epicardium/drivers/display/api.c

+#include "epicardium.h"
+#include "drivers/display/lcd.h"
+#include "drivers/display/epic_ctx.h"
+
+#include "FreeRTOS.h"
+#include "LCD_Driver.h"
+#include "gpio.h"
+#include "task.h"
+#include "tmr.h"
+#include "tmr_utils.h"
+
+#include <machine/endian.h>
+#include <string.h>
+
+static TaskHandle_t lock = NULL;
+
+static int check_lock()
+{
+	TaskHandle_t task = xTaskGetCurrentTaskHandle();
+	if (task != lock) {
+		return -EBUSY;
+	} else {
+		return 0;
+	}
+}
+
+static uint16_t rgb888_to_rgb565(uint8_t *bytes)
+{
+	return ((bytes[0] & 0b11111000) << 8) | ((bytes[1] & 0b11111100) << 3) |
+	       (bytes[2] >> 3);
+}
+
+static inline void
+rgb565_to_rgb888(uint16_t pixel, uint8_t *red, uint8_t *green, uint8_t *blue)
+{
+	*blue  = (pixel & 31) << 3;
+	*green = ((pixel >> 5) & 63) << 2;
+	*red   = ((pixel >> 11) & 31) << 3;
+}
+
+int epic_disp_print(
+	int16_t posx,
+	int16_t posy,
+	const char *pString,
+	uint16_t fg,
+	uint16_t bg
+) {
+	return epic_disp_print_adv(DISP_FONT20, posx, posy, pString, fg, bg);
+}
+
+static const float font_map[] = {
+	[DISP_FONT8] = 8.0f,   [DISP_FONT12] = 12.0f, [DISP_FONT16] = 16.0f,
+	[DISP_FONT20] = 20.0f, [DISP_FONT24] = 24.0f,
+};
+
+int epic_disp_print_adv(
+	uint8_t font,
+	int16_t posx,
+	int16_t posy,
+	const char *pString,
+	uint16_t fg,
+	uint16_t bg
+) {
+	uint8_t r, g, b;
+	int cl = check_lock();
+	if (cl < 0) {
+		return cl;
+	}
+
+	if (font >= (sizeof(font_map) / sizeof(font_map[0]))) {
+		return -EINVAL;
+	}
+
+	float font_size = font_map[font];
+	ctx_font_size(epicardium_ctx, font_size);
+
+	if (fg != bg) {
+		/* non-transparent background */
+		rgb565_to_rgb888(bg, &r, &g, &b);
+		ctx_rgba8(epicardium_ctx, r, g, b, 255);
+		float width = ctx_text_width(epicardium_ctx, pString);
+		ctx_rectangle(epicardium_ctx, posx, posy, width, font_size);
+		ctx_fill(epicardium_ctx);
+	}
+
+	rgb565_to_rgb888(fg, &r, &g, &b);
+	ctx_rgba8(epicardium_ctx, r, g, b, 255);
+	ctx_move_to(epicardium_ctx, posx, (float)posy + font_size * 0.8f);
+	ctx_text(epicardium_ctx, pString);
+
+	return 0;
+}
+
+int epic_disp_clear(uint16_t color)
+{
+	int cl = check_lock();
+	if (cl < 0) {
+		return cl;
+	}
+
+	/*
+	 * We could use ctx for this but it's much easier to just clear the
+	 * framebuffer directly.
+	 */
+	for (size_t i = 0; i < sizeof(epicardium_ctx_fb); i += 2) {
+		epicardium_ctx_fb[i]     = color >> 8;
+		epicardium_ctx_fb[i + 1] = color & 0xff;
+	}
+
+	return 0;
+}
+
+int epic_disp_pixel(int16_t x, int16_t y, uint16_t color)
+{
+	int cl = check_lock();
+	if (cl < 0) {
+		return cl;
+	}
+
+	uint8_t r, g, b;
+	rgb565_to_rgb888(color, &r, &g, &b);
+	ctx_set_pixel_u8(epicardium_ctx, x, y, r, g, b, 255);
+
+	return 0;
+}
+
+static uint16_t rgb565_pixel_from_buf(
+	uint8_t *img,
+	enum epic_rgb_format format,
+	int16_t width,
+	int16_t x,
+	int16_t y,
+	uint8_t *alpha
+) {
+	uint16_t tmp16;
+	uint8_t rgba[4];
+
+	switch (format) {
+	case EPIC_RGB565:
+		*alpha = 255;
+		memcpy(&tmp16, &img[y * width * 2 + x * 2], 2);
+		return tmp16;
+	case EPIC_RGBA5551:
+		memcpy(&tmp16, &img[y * width * 2 + x * 2], 2);
+		*alpha = (tmp16 & 0x01) ? 255 : 0;
+		return (tmp16 & 0xFFC0) | ((tmp16 & 0x3E) >> 1);
+	case EPIC_RGB8:
+		*alpha = 255;
+		memcpy(rgba, &img[y * width * 3 + x * 3], 3);
+		return rgb888_to_rgb565(rgba);
+	case EPIC_RGBA8:
+		memcpy(rgba, &img[y * width * 4 + x * 4], 4);
+		*alpha = rgba[3];
+		return rgb888_to_rgb565(rgba);
+	default:
+		return 0xFFFF;
+	}
+}
+
+int epic_disp_blit(
+	int16_t pos_x,
+	int16_t pos_y,
+	int16_t width,
+	int16_t height,
+	void *img,
+	enum epic_rgb_format format
+) {
+	int cl = check_lock();
+	if (cl < 0) {
+		return cl;
+	}
+
+	for (int16_t xsrc = 0; xsrc < width; xsrc += 1) {
+		for (int16_t ysrc = 0; ysrc < height; ysrc += 1) {
+			int16_t xscreen = pos_x + xsrc;
+			int16_t yscreen = pos_y + ysrc;
+			size_t offset   = yscreen * 160 * 2 + xscreen * 2;
+			if (xscreen < 0 || xscreen >= 160 || yscreen < 0 ||
+			    yscreen >= 80) {
+				continue;
+			}
+
+			uint8_t alpha  = 255;
+			uint16_t pixel = rgb565_pixel_from_buf(
+				img, format, width, xsrc, ysrc, &alpha
+			);
+
+			if (alpha == 0) {
+				continue;
+			}
+
+			epicardium_ctx_fb[offset]     = (pixel & 0xFF00) >> 8;
+			epicardium_ctx_fb[offset + 1] = pixel & 0xFF;
+		}
+	}
+
+	return 0;
+}
+
+int epic_disp_line(
+	int16_t xstart,
+	int16_t ystart,
+	int16_t xend,
+	int16_t yend,
+	uint16_t color,
+	enum disp_linestyle linestyle,
+	uint16_t pixelsize
+) {
+	int cl = check_lock();
+	if (cl < 0) {
+		return cl;
+	}
+
+	float xstartf = xstart, ystartf = ystart, xendf = xend, yendf = yend;
+
+	/*
+	 * For odd line widths, shift the line by half a pixel so it aligns
+	 * perfectly with the pixel grid.
+	 */
+	if (pixelsize % 2 == 1) {
+		xstartf += 0.5f;
+		ystartf += 0.5f;
+		yendf += 0.5f;
+		xendf += 0.5f;
+	}
+
+	uint8_t r, g, b;
+	rgb565_to_rgb888(color, &r, &g, &b);
+	ctx_rgba8_stroke(epicardium_ctx, r, g, b, 255);
+
+	ctx_line_width(epicardium_ctx, pixelsize);
+	ctx_move_to(epicardium_ctx, xstartf, ystartf);
+	ctx_line_to(epicardium_ctx, xendf, yendf);
+	ctx_stroke(epicardium_ctx);
+
+	return 0;
+}
+
+int epic_disp_rect(
+	int16_t xstart,
+	int16_t ystart,
+	int16_t xend,
+	int16_t yend,
+	uint16_t color,
+	enum disp_fillstyle fillstyle,
+	uint16_t pixelsize
+) {
+	int cl = check_lock();
+	if (cl < 0)
+		return cl;
+
+	uint8_t r, g, b;
+	rgb565_to_rgb888(color, &r, &g, &b);
+
+	ctx_rectangle(
+		epicardium_ctx,
+		xstart,
+		ystart,
+		xend - xstart + 1,
+		yend - ystart + 1
+	);
+
+	switch (fillstyle) {
+	case FILLSTYLE_EMPTY:
+		ctx_rgba8_stroke(epicardium_ctx, r, g, b, 255);
+		ctx_line_width(epicardium_ctx, pixelsize);
+		ctx_stroke(epicardium_ctx);
+		break;
+	case FILLSTYLE_FILLED:
+		ctx_rgba8(epicardium_ctx, r, g, b, 255);
+		ctx_fill(epicardium_ctx);
+		break;
+	}
+
+	return 0;
+}
+
+int epic_disp_circ(
+	int16_t x,
+	int16_t y,
+	uint16_t rad,
+	uint16_t color,
+	enum disp_fillstyle fillstyle,
+	uint16_t pixelsize
+) {
+	int cl = check_lock();
+	if (cl < 0)
+		return cl;
+
+	uint8_t r, g, b;
+	rgb565_to_rgb888(color, &r, &g, &b);
+
+	ctx_arc(epicardium_ctx, x, y, rad, 0.0f, CTX_PI * 1.95, 0);
+
+	switch (fillstyle) {
+	case FILLSTYLE_EMPTY:
+		ctx_rgba8_stroke(epicardium_ctx, r, g, b, 255);
+		ctx_line_width(epicardium_ctx, pixelsize);
+		ctx_stroke(epicardium_ctx);
+		break;
+	case FILLSTYLE_FILLED:
+		ctx_rgba8(epicardium_ctx, r, g, b, 255);
+		ctx_fill(epicardium_ctx);
+		break;
+	}
+
+	return 0;
+}
+
+int epic_disp_update()
+{
+	int cl = check_lock();
+	if (cl < 0) {
+		return cl;
+	}
+
+	lcd_write_fb(epicardium_ctx_fb);
+
+	return 0;
+}
+
+int epic_disp_framebuffer(union disp_framebuffer *fb)
+{
+	int cl = check_lock();
+	if (cl < 0) {
+		return cl;
+	}
+
+	/*
+	 * Flip the screen because that's what this API call historically
+	 * expects.
+	 */
+	lcd_set_screenflip(true);
+	lcd_write_fb(fb->raw);
+	lcd_set_screenflip(false);
+	return 0;
+}
+
+int epic_disp_backlight(uint16_t brightness)
+{
+	/* TODO: lock? */
+	if (brightness == 0) {
+		lcd_set_sleep(true);
+	} else {
+		lcd_set_sleep(false);
+	}
+	LCD_SetBacklight(brightness);
+	return 0;
+}
+
+int epic_disp_open()
+{
+	TaskHandle_t task = xTaskGetCurrentTaskHandle();
+	if (lock == task) {
+		return 0;
+	} else if (lock == NULL) {
+		lock = task;
+		return 0;
+	} else {
+		return -EBUSY;
+	}
+}
+
+int epic_disp_close()
+{
+	if (check_lock() < 0 && lock != NULL) {
+		return -EBUSY;
+	} else {
+		lock = NULL;
+		return 0;
+	}
+}
+
+void disp_update_backlight_clock(void)
+{
+	LCD_UpdateBacklightClock();
+}
+
+void disp_forcelock()
+{
+	TaskHandle_t task = xTaskGetCurrentTaskHandle();
+	lock              = task;
+}

epicardium/drivers/display/epic_ctx.h

+#pragma once
+
+#include "ctx.h"
+
+extern Ctx *epicardium_ctx;
+extern uint8_t epicardium_ctx_fb[160 * 80 * 2];

epicardium/drivers/display/init.c

+#include "drivers/display/lcd.h"
+#include "drivers/display/epic_ctx.h"
+#include "drivers/drivers.h"
+#include "display.h"
+
+#include "ctx.h"
+
+#include <stdint.h>
+#include <machine/endian.h>
+
+#if BYTE_ORDER == LITTLE_ENDIAN
+#define CARD10_CTX_FORMAT CTX_FORMAT_RGB565_BYTESWAPPED
+#else
+#define CARD10_CTX_FORMAT CTX_FORMAT_RGB565
+#endif
+
+uint8_t epicardium_ctx_fb[160 * 80 * 2] = { 0 };
+Ctx *epicardium_ctx                     = NULL;
+
+void disp_init(void)
+{
+	/*
+	 * The bootloader has already initialized the display, so we only need
+	 * to do the bare minimum here.
+	 */
+	lcd_reconfigure();
+
+	/*
+	 * Initialize the graphics context.
+	 */
+	disp_ctx_reinit();
+}
+
+void disp_ctx_reinit(void)
+{
+	if (epicardium_ctx != NULL) {
+		ctx_free(epicardium_ctx);
+	}
+
+	epicardium_ctx = ctx_new_for_framebuffer(
+		epicardium_ctx_fb, 160, 80, 160 * 2, CARD10_CTX_FORMAT
+	);
+
+	/* set some defaults */
+	ctx_rgba(epicardium_ctx, 1.0f, 1.0f, 1.0f, 1.0f);
+	ctx_rgba_stroke(epicardium_ctx, 1.0f, 1.0f, 1.0f, 1.0f);
+	ctx_font(epicardium_ctx, "ctx-mono");
+}

epicardium/drivers/display/lcd.c

+#include "os/core.h"
+
+#include "MAX77650-Arduino-Library.h"
+#include "gpio.h"
+#include "mxc_delay.h"
+#include "portexpander.h"
+#include "spi.h"
+
+#include <machine/endian.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+/* HAL Interfaces {{{ */
+static const gpio_cfg_t GPIO_PIN_DC = {
+	PORT_1, PIN_6, GPIO_FUNC_OUT, GPIO_PAD_NONE
+};
+
+static void lcd_hw_init(void)
+{
+	GPIO_Config(&GPIO_PIN_DC);
+
+	/* for the reset pin */
+	if (!portexpander_detected()) {
+		/* Open-drain */
+		MAX77650_setDRV(false);
+		/* Output */
+		MAX77650_setDIR(false);
+	}
+}
+
+static void lcd_set_dc(bool state)
+{
+	if (state) {
+		GPIO_OutSet(&GPIO_PIN_DC);
+	} else {
+		GPIO_OutClr(&GPIO_PIN_DC);
+	}
+}
+
+static void lcd_set_rst(bool state)
+{
+	if (!portexpander_detected()) {
+		MAX77650_setDO(state ? true : false);
+	} else {
+		portexpander_out_put(PIN_4, state ? 0xFF : 0);
+	}
+}
+
+/** Bit Rate. Display has 15 MHz limit */
+#define SPI_SPEED (15 * 1000 * 1000)
+
+static void lcd_spi_write(const uint8_t *data, size_t count)
+{
+	const sys_cfg_spi_t spi_master_cfg = {
+		.map    = MAP_A,
+		.ss0    = Enable,
+		.ss1    = Disable,
+		.ss2    = Disable,
+		.num_io = 2,
+	};
+	spi_req_t request = {
+		.ssel     = 0,
+		.deass    = 1,
+		.ssel_pol = SPI17Y_POL_LOW,
+		.tx_data  = data,
+		.rx_data  = NULL,
+		.width    = SPI17Y_WIDTH_1,
+		.len      = count,
+		.bits     = 8,
+		.rx_num   = 0,
+		.tx_num   = 0,
+		.callback = NULL,
+	};
+	if (SPI_Init(SPI2, 0, SPI_SPEED, spi_master_cfg) != 0) {
+		panic("Error configuring display SPI");
+	}
+	SPI_MasterTrans(SPI2, &request);
+}
+
+static void lcd_delay(size_t millis)
+{
+	// TODO: Is this what we want?
+	mxc_delay(millis * 1000);
+}
+/* HAL Interfaces }}} */
+
+enum lcd_commands {
+	/** Sleep In */
+	LCD_SLPIN = 0x10,
+	/** Sleep Out */
+	LCD_SLPOUT = 0x11,
+	/** Display Inversion On */
+	LCD_INVON = 0x21,
+	/** Display On */
+	LCD_DISPON = 0x29,
+	/** Column Address Set */
+	LCD_CASET = 0x2A,
+	/** Row Address Set */
+	LCD_RASET = 0x2B,
+	/** Memory Write */
+	LCD_RAMWR = 0x2C,
+	/** Memory Data Access Control */
+	LCD_MADCTL = 0x36,
+	/** Interface Pixel Format */
+	LCD_COLMOD = 0x3A,
+	/** Frame Rate Control (In normal mode/ Full colors) */
+	LCD_FRMCTR1 = 0xB1,
+	/** Frame Rate Control (In Idle mode/ 8-colors) */
+	LCD_FRMCTR2 = 0xB2,
+	/** Frame Rate Control (In Partial mode/ full colors) */
+	LCD_FRMCTR3 = 0xB3,
+	/** Display Inversion Control */
+	LCD_INVCTR = 0xB4,
+	/** Power Control 1 */
+	LCD_PWCTR1 = 0xC0,
+	/** Power Control 2 */
+	LCD_PWCTR2 = 0xC1,
+	/** Power Control 3 (in Normal mode/ Full colors) */
+	LCD_PWCTR3 = 0xC2,
+	/** Power Control 4 (in Idle mode/ 8-colors) */
+	LCD_PWCTR4 = 0xC3,
+	/** Power Control 5 (in Partial mode/ full-colors) */
+	LCD_PWCTR5 = 0xC4,
+	/** VCOM Control 1 */
+	LCD_VMCTR1 = 0xC5,
+	/** Gamma (+ polarity) Correction Characteristics Setting */
+	LCD_GMCTRP1 = 0xE0,
+	/** Gamma (- polarity) Correction Characteristics Setting */
+	LCD_GMCTRN1 = 0xE1,
+};
+
+enum madctl_bits {
+	MADCTL_MY  = 0x80,
+	MADCTL_MX  = 0x40,
+	MADCTL_MV  = 0x20,
+	MADCTL_ML  = 0x10,
+	MADCTL_RGB = 0x08,
+	MADCTL_MH  = 0x04,
+};
+
+static void
+lcd_send_command(enum lcd_commands cmd, const uint8_t *args, size_t count)
+{
+	lcd_set_dc(false);
+	lcd_spi_write((uint8_t *)&cmd, 1);
+	if (args != NULL && count != 0) {
+		lcd_set_dc(true);
+		lcd_spi_write(args, count);
+	}
+}
+
+static void lcd_hard_reset(void)
+{
+	lcd_delay(20);
+	lcd_set_rst(false);
+	lcd_delay(20);
+	lcd_set_rst(true);
+	lcd_delay(20);
+}
+
+void lcd_set_sleep(bool sleep)
+{
+	static int current_sleep = -1;
+
+	if (sleep == current_sleep) {
+		return;
+	}
+	current_sleep = sleep;
+
+	if (sleep) {
+		lcd_send_command(LCD_SLPIN, NULL, 0);
+	} else {
+		lcd_send_command(LCD_SLPOUT, NULL, 0);
+	}
+}
+
+/**
+ * Perform a minimal initialization under the assumption that the bootloader has
+ * already turned on the display.  This is faster and prevents visible
+ * reinitialization artifacts.
+ */
+void lcd_reconfigure(void)
+{
+	/* Invert Display (twice for unknown reasons ...). */
+	lcd_send_command(LCD_INVON, NULL, 0);
+	lcd_send_command(LCD_INVON, NULL, 0);
+
+	/* Set framerate control values for all modes to the same values. */
+	const uint8_t frmctr[] = { 0x05, 0x3A, 0x3A, 0x05, 0x3A, 0x3A };
+	lcd_send_command(LCD_FRMCTR1, frmctr, 3);
+	lcd_send_command(LCD_FRMCTR2, frmctr, 3);
+	lcd_send_command(LCD_FRMCTR3, frmctr, 6);
+
+	/* Set display inversion control (unsure what this does?). */
+	const uint8_t invctr[] = { 0x03 };
+	lcd_send_command(LCD_INVCTR, invctr, sizeof(invctr));
+
+	/* Configure GVDD voltage to 4.7V. */
+	const uint8_t pwctr1[] = { 0x62, 0x02, 0x04 };
+	lcd_send_command(LCD_PWCTR1, pwctr1, sizeof(pwctr1));
+
+	/* Configure only ignored bits? */
+	const uint8_t pwctr2[] = { 0xC0 };
+	lcd_send_command(LCD_PWCTR2, pwctr2, sizeof(pwctr2));
+
+	/*
+	 * Configure "large" amount of current in operational amplifier and
+	 * booster step-ups for all modes.
+	 */
+	const uint8_t pwctr3[] = { 0x0D, 0x00 }, pwctr4[] = { 0x8D, 0x6A },
+		      pwctr5[] = { 0x8D, 0xEE };
+	lcd_send_command(LCD_PWCTR3, pwctr3, sizeof(pwctr3));
+	lcd_send_command(LCD_PWCTR4, pwctr4, sizeof(pwctr4));
+	lcd_send_command(LCD_PWCTR5, pwctr5, sizeof(pwctr5));
+
+	/* Configure VCOMH voltage to 2.850V. */
+	const uint8_t vmctr1[] = { 0x0E };
+	lcd_send_command(LCD_VMCTR1, vmctr1, sizeof(vmctr1));
+
+	/* Write positive and negative gamma correction values. */
+	const uint8_t gmctrp1[] = {
+		0x10, 0x0E, 0x02, 0x03, 0x0E, 0x07, 0x02, 0x07,
+		0x0A, 0x12, 0x27, 0x37, 0x00, 0x0D, 0x0E, 0x10,
+	};
+	const uint8_t gmctrn1[] = {
+		0x10, 0x0E, 0x03, 0x03, 0x0F, 0x06, 0x02, 0x08,
+		0x0A, 0x13, 0x26, 0x36, 0x00, 0x0D, 0x0E, 0x10,
+	};
+	lcd_send_command(LCD_GMCTRP1, gmctrp1, sizeof(gmctrp1));
+	lcd_send_command(LCD_GMCTRN1, gmctrn1, sizeof(gmctrn1));
+
+	/* Configure 16-bit pixel format. */
+	const uint8_t colmod[] = { 0x05 };
+	lcd_send_command(LCD_COLMOD, colmod, sizeof(colmod));
+
+	/*
+	 * Configure "MADCTL", which defines the pixel and color access order.
+	 */
+	const uint8_t madctl[] = { MADCTL_MX | MADCTL_MV | MADCTL_RGB };
+	/*
+	 * Waveshare Driver:
+	 * const uint8_t madctl[] = { MADCTL_MY | MADCTL_MV | MADCTL_RGB };
+	 */
+	lcd_send_command(LCD_MADCTL, madctl, sizeof(madctl));
+
+	/* Turn the display on. */
+	lcd_send_command(LCD_DISPON, NULL, 0);
+}
+
+/**
+ * Perform a full initialization of the display.  This will ensure the display
+ * is in a deterministic state.
+ */
+void lcd_initialize(void)
+{
+	lcd_hw_init();
+
+	lcd_hard_reset();
+
+	lcd_send_command(LCD_SLPOUT, NULL, 0);
+	lcd_delay(120);
+
+	lcd_reconfigure();
+}
+
+/**
+ * Write a partial display update.
+ *
+ * The rectangle from column ``xstart`` to ``xend`` (inclusive) and row
+ * ``ystart`` to ``yend`` (inclusive) will be updated with the contents of
+ * ``fb``.
+ *
+ * ``fb`` **must** have a size of
+ * ``(xend - xstart + 1) * (yend - ystart + 1) * 2`` bytes.
+ */
+void lcd_write_fb_partial(
+	uint16_t xstart,
+	uint16_t ystart,
+	uint16_t xend,
+	uint16_t yend,
+	const uint8_t *fb
+) {
+	uint16_t param_buffer[2];
+
+	/* Column start and end are offset by 1. */
+	param_buffer[0] = __htons(xstart + 1);
+	param_buffer[1] = __htons(xend + 1);
+	lcd_send_command(
+		LCD_CASET, (uint8_t *)param_buffer, sizeof(param_buffer)
+	);
+
+	/* Row start and end are offset by a magic 26. */
+	param_buffer[0] = __htons(ystart + 26);
+	param_buffer[1] = __htons(yend + 26);
+	lcd_send_command(
+		LCD_RASET, (uint8_t *)param_buffer, sizeof(param_buffer)
+	);
+
+	/* Now write out the actual framebuffer contents. */
+	size_t fb_size = (xend - xstart + 1) * (yend - ystart + 1) * 2;
+	lcd_send_command(LCD_RAMWR, fb, fb_size);
+}
+
+/**
+ * Write out a full framebuffer update.
+ *
+ * ``fb`` **must** be 160 * 80 * 2 = **25600** bytes in size.  The pixels are
+ * ordered in rows starting at the top left of the screen.  Each pixel must have
+ * its bytes laid out as big endian (while the CPU is little endian!).
+ */
+void lcd_write_fb(const uint8_t *fb)
+{
+	lcd_write_fb_partial(0, 0, 159, 79, fb);
+}
+
+/**
+ * Flip the screen orientation upside down.
+ *
+ * Historically we had software perform a flip of the framebuffer before
+ * sending it out.  This function provides a way to make the hardware accept
+ * such a flipped framebuffer.  This exists mostly to support the
+ * :c:func:`epic_disp_framebuffer()` API call for legacy l0dables.
+ */
+void lcd_set_screenflip(bool flipped)
+{
+	const uint8_t madctl_upright[] = { MADCTL_MX | MADCTL_MV | MADCTL_RGB };
+	const uint8_t madctl_flipped[] = { MADCTL_MY | MADCTL_MV | MADCTL_RGB };
+	if (flipped) {
+		lcd_send_command(LCD_MADCTL, madctl_flipped, 1);
+	} else {
+		lcd_send_command(LCD_MADCTL, madctl_upright, 1);
+	}
+}

epicardium/drivers/display/lcd.h

+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+
+void lcd_set_sleep(bool sleep);
+void lcd_reconfigure(void);
+void lcd_initialize(void);
+void lcd_write_fb_partial(
+	uint16_t xstart,
+	uint16_t ystart,
+	uint16_t xend,
+	uint16_t yend,
+	const uint8_t *fb
+);
+void lcd_write_fb(const uint8_t *fb);
+void lcd_set_screenflip(bool flipped);

epicardium/drivers/drivers.h

+#ifndef DRIVERS_H
+#define DRIVERS_H
+
+#include "FreeRTOS.h"
+#include "gpio.h"
+#include "os/mutex.h"
+#include "epicardium.h"
+
+#include <stdint.h>
+#include <stdbool.h>
+
+/* ---------- Serial ------------------------------------------------------- */
+#define SERIAL_READ_BUFFER_SIZE 128
+#define SERIAL_WRITE_STREAM_BUFFER_SIZE 512
+void serial_init();
+void vSerialTask(void *pvParameters);
+void serial_enqueue_char(char chr);
+void serial_flush(void);
+extern TaskHandle_t serial_task_id;
+/* Turn off the print queue and do prints synchroneous from now on. */
+void serial_return_to_synchronous();
+
+// For the eSetBit xTaskNotify task semaphore trigger
+enum serial_notify{
+	SERIAL_WRITE_NOTIFY = 0x01,
+	SERIAL_READ_NOTIFY  = 0x02,
+};
+
+/* ---------- PMIC --------------------------------------------------------- */
+void vPmicTask(void *pvParameters);
+
+/* ---------- Watchdog ----------------------------------------------------- */
+void watchdog_init();
+void watchdog_clearer_init();
+
+/* Critical battery voltage */
+#define BATTERY_CRITICAL   3.40f
+
+enum pmic_amux_signal {
+	PMIC_AMUX_DISABLED    = 0x0,
+	PMIC_AMUX_CHGIN_U     = 0x1,
+	PMIC_AMUX_CHGIN_I     = 0x2,
+	PMIC_AMUX_BATT_U      = 0x3,
+	PMIC_AMUX_BATT_CHG_I  = 0x4,
+	PMIC_AMUX_BATT_DIS_I  = 0x5,
+	PMIC_AMUX_BATT_NULL_I = 0x6,
+	PMIC_AMUX_THM_U       = 0x7,
+	PMIC_AMUX_TBIAS_U     = 0x8,
+	PMIC_AMUX_AGND_U      = 0x9,
+	PMIC_AMUX_SYS_U       = 0xA,
+	_PMIC_AMUX_MAX,
+};
+
+/*
+ * Read a value from the PMIC's AMUX.  The result is already converted into its
+ * proper unit.  See the MAX77650 datasheet for details.
+ */
+int pmic_read_amux(enum pmic_amux_signal sig, float *result);
+
+
+/* ---------- Display ------------------------------------------------------ */
+/* Do display and graphics initialization/configuration. */
+void disp_init(void);
+/* Reinitialize the graphics context. */
+void disp_ctx_reinit(void);
+/* Forces an unlock of the display. Only to be used in Epicardium */
+void disp_forcelock();
+void disp_update_backlight_clock(void);
+
+/* ---------- BHI160 ------------------------------------------------------- */
+#define BHI160_FIFO_SIZE             128
+#define BHI160_MUTEX_WAIT_MS          50
+void vBhi160Task(void *pvParameters);
+
+/* ---------- BME680 ------------------------------------------------------- */
+void bme680_periodic(int period);
+
+/* ---------- MAX86150 ----------------------------------------------------- */
+#define MAX86150_MUTEX_WAIT_MS		50
+void vMAX86150Task(void *pvParameters);
+void max86150_mutex_init(void);
+
+
+/* ---------- MAX30001 ----------------------------------------------------- */
+void vMAX30001Task(void *pvParameters);
+void max30001_mutex_init(void);
+
+/* ---------- GPIO --------------------------------------------------------- */
+extern gpio_cfg_t gpio_configs[];
+
+/* ---------- BSEC / BME680 ------------------------------------------------ */
+int bsec_activate(void);
+void vBSECTask(void *pvParameters);
+bool bsec_active(void);
+struct bme680_sensor_data;
+int bsec_read_bme680(struct bme680_sensor_data *data);
+
+/* ---------- Sleep -------------------------------------------------------- */
+void sleep_deepsleep(void);
+
+/* ---------- RNG ---------------------------------------------------------- */
+void rng_init(void);
+
+#endif /* DRIVERS_H */

epicardium/drivers/gpio.c

+#include "epicardium.h"
+#include "gpio.h"
+#include "max32665.h"
+#include "mxc_sys.h"
+#include "adc.h"
+#include "mxc_errors.h"
+#include "os/core.h"
+#include "modules/modules.h"
+
+/*
+ * Despite what the schematic (currently, 2019-08-18) says these are the correct
+ * pins for wristband GPIO 1-4 (not 0-3 as the schematic states)
+ */
+gpio_cfg_t gpio_configs[] = {
+	[EPIC_GPIO_WRISTBAND_1] = { PORT_0,
+				    PIN_21,
+				    GPIO_FUNC_OUT,
+				    GPIO_PAD_NONE },
+	[EPIC_GPIO_WRISTBAND_2] = { PORT_0,
+				    PIN_22,
+				    GPIO_FUNC_OUT,
+				    GPIO_PAD_NONE },
+	[EPIC_GPIO_WRISTBAND_3] = { PORT_0,
+				    PIN_29,
+				    GPIO_FUNC_OUT,
+				    GPIO_PAD_NONE },
+	[EPIC_GPIO_WRISTBAND_4] = { PORT_0,
+				    PIN_20,
+				    GPIO_FUNC_OUT,
+				    GPIO_PAD_NONE },
+};
+
+static int s_adc_channels[] = {
+	[EPIC_GPIO_WRISTBAND_1] = ADC_CH_5,
+	[EPIC_GPIO_WRISTBAND_2] = ADC_CH_6,
+	/* on P0.29, there is no ADC available
+	 * see GPIO matrix in MAX32665-MAX32668.pdf,
+	 * pages 32,33
+	 */
+	[EPIC_GPIO_WRISTBAND_3] = -1,
+	[EPIC_GPIO_WRISTBAND_4] = ADC_CH_4,
+};
+
+int epic_gpio_set_pin_mode(uint8_t pin, uint8_t mode)
+{
+	if (pin < EPIC_GPIO_WRISTBAND_1 || pin > EPIC_GPIO_WRISTBAND_4)
+		return -EINVAL;
+
+	gpio_cfg_t *cfg = &gpio_configs[pin];
+
+	if (mode & EPIC_GPIO_MODE_ADC) {
+		if (s_adc_channels[pin] == -1) {
+			LOG_WARN("gpio", "ADC not available on pin %d", pin);
+			return -EINVAL;
+		}
+		cfg->func = GPIO_FUNC_ALT1;
+		if (mode & EPIC_GPIO_MODE_OUT) {
+			return -EINVAL;
+		}
+	} else if (mode & EPIC_GPIO_MODE_IN) {
+		cfg->func = GPIO_FUNC_IN;
+		if (mode & EPIC_GPIO_MODE_OUT) {
+			return -EINVAL;
+		}
+	} else if (mode & EPIC_GPIO_MODE_OUT) {
+		cfg->func = GPIO_FUNC_OUT;
+		if (mode & EPIC_GPIO_MODE_IN) {
+			return -EINVAL;
+		}
+	} else {
+		return -EINVAL;
+	}
+
+	if (!(mode & EPIC_GPIO_MODE_ADC)) {
+		if (mode & EPIC_GPIO_PULL_UP) {
+			cfg->pad = GPIO_PAD_PULL_UP;
+		} else if (mode & EPIC_GPIO_PULL_DOWN) {
+			cfg->pad = GPIO_PAD_PULL_DOWN;
+		} else {
+			cfg->pad = GPIO_PAD_NONE;
+		}
+	} else {
+		cfg->pad = GPIO_PAD_NONE;
+	}
+
+	if (GPIO_Config(cfg) != E_NO_ERROR)
+		return -EINVAL;
+	return 0;
+}
+
+int epic_gpio_get_pin_mode(uint8_t pin)
+{
+	if (pin < EPIC_GPIO_WRISTBAND_1 || pin > EPIC_GPIO_WRISTBAND_4)
+		return -EINVAL;
+
+	gpio_cfg_t *cfg = &gpio_configs[pin];
+	int res         = 0;
+	if (cfg->func == GPIO_FUNC_IN)
+		res |= EPIC_GPIO_MODE_IN;
+	else if (cfg->func == GPIO_FUNC_OUT)
+		res |= EPIC_GPIO_MODE_OUT;
+	else if (cfg->func == GPIO_FUNC_ALT1)
+		res |= EPIC_GPIO_MODE_ADC;
+	if (cfg->pad == GPIO_PAD_PULL_UP)
+		res |= EPIC_GPIO_PULL_UP;
+	else if (cfg->pad == GPIO_PAD_PULL_DOWN)
+		res |= EPIC_GPIO_PULL_DOWN;
+
+	return res;
+}
+
+int epic_gpio_write_pin(uint8_t pin, bool on)
+{
+	if (pin < EPIC_GPIO_WRISTBAND_1 || pin > EPIC_GPIO_WRISTBAND_4)
+		return -EINVAL;
+
+	gpio_cfg_t *cfg = &gpio_configs[pin];
+	if (cfg->func == GPIO_FUNC_IN)
+		return -EINVAL;
+
+	if (on)
+		GPIO_OutSet(cfg);
+	else
+		GPIO_OutClr(cfg);
+
+	return 0;
+}
+
+int epic_gpio_read_pin(uint8_t pin)
+{
+	if (pin < EPIC_GPIO_WRISTBAND_1 || pin > EPIC_GPIO_WRISTBAND_4)
+		return -EINVAL;
+
+	gpio_cfg_t *cfg = &gpio_configs[pin];
+	if (cfg->func == GPIO_FUNC_OUT) {
+		return GPIO_OutGet(cfg) != 0;
+	} else if (cfg->func == GPIO_FUNC_IN) {
+		return GPIO_InGet(cfg) != 0;
+	} else if (cfg->func == GPIO_FUNC_ALT1) {
+		hwlock_acquire(HWLOCK_ADC);
+		ADC_StartConvert(s_adc_channels[pin], 0, 0);
+		uint16_t value;
+		int rc = ADC_GetData(&value);
+		hwlock_release(HWLOCK_ADC);
+		if (rc < 0) {
+			return -EIO;
+		}
+		return (int)value;
+	} else {
+		return -EINVAL;
+	}
+}

epicardium/drivers/leds.c

+#include "leds.h"
+#include "pmic.h"
+#include "FreeRTOS.h"
+#include "timers.h"
+#include "task.h"
+#include "epicardium.h"
+#include "modules/modules.h"
+
+#include <stdbool.h>
+
+/*
+ * TODO: create smth like vTaskDelay(pdMS_TO_TICKS(//put ms here)) for us,
+ *       remove blocking delay from /lib/leds.c to avoid process blocking
+ */
+
+#define NUM_LEDS 15 /* Take from lib/card10/leds.c */
+
+static void do_update(void)
+{
+	hwlock_acquire(HWLOCK_LED);
+	hwlock_acquire(HWLOCK_I2C);
+
+	leds_update_power();
+	leds_update();
+
+	hwlock_release(HWLOCK_I2C);
+	hwlock_release(HWLOCK_LED);
+}
+
+void epic_leds_set(int led, uint8_t r, uint8_t g, uint8_t b)
+{
+	if (led == PERSONAL_STATE_LED && personal_state_enabled())
+		return;
+
+	leds_prep(led, r, g, b);
+	do_update();
+}
+
+void epic_leds_set_hsv(int led, float h, float s, float v)
+{
+	if (led == PERSONAL_STATE_LED && personal_state_enabled())
+		return;
+
+	leds_prep_hsv(led, h, s, v);
+	do_update();
+}
+
+void epic_leds_prep(int led, uint8_t r, uint8_t g, uint8_t b)
+{
+	if (led == PERSONAL_STATE_LED && personal_state_enabled())
+		return;
+
+	leds_prep(led, r, g, b);
+}
+
+int epic_leds_get_rgb(int led, uint8_t *rgb)
+{
+	if (led == PERSONAL_STATE_LED && personal_state_enabled())
+		return -EPERM;
+	if (led < 0 || led >= NUM_LEDS)
+		return -EINVAL;
+
+	leds_get_rgb(led, rgb);
+	return 0;
+}
+
+void epic_leds_prep_hsv(int led, float h, float s, float v)
+{
+	if (led == PERSONAL_STATE_LED && personal_state_enabled())
+		return;
+
+	leds_prep_hsv(led, h, s, v);
+}
+
+void epic_leds_set_all(uint8_t *pattern_ptr, uint8_t len)
+{
+	uint8_t(*pattern)[3] = (uint8_t(*)[3])pattern_ptr;
+	for (int i = 0; i < len; i++) {
+		if (i == PERSONAL_STATE_LED && personal_state_enabled())
+			continue;
+
+		leds_prep(i, pattern[i][0], pattern[i][1], pattern[i][2]);
+	}
+	do_update();
+}
+
+void epic_leds_set_all_hsv(float *pattern_ptr, uint8_t len)
+{
+	float(*pattern)[3] = (float(*)[3])pattern_ptr;
+	for (int i = 0; i < len; i++) {
+		if (i == PERSONAL_STATE_LED && personal_state_enabled())
+			continue;
+
+		leds_prep_hsv(i, pattern[i][0], pattern[i][1], pattern[i][2]);
+	}
+	do_update();
+}
+
+void epic_leds_dim_top(uint8_t value)
+{
+	leds_set_dim_top(value);
+	if (personal_state_enabled() == 0) {
+		do_update();
+	}
+}
+
+void epic_leds_dim_bottom(uint8_t value)
+{
+	leds_set_dim_bottom(value);
+	if (personal_state_enabled() == 0) {
+		do_update();
+	}
+}
+
+void epic_leds_set_rocket(int led, uint8_t value)
+{
+	hwlock_acquire(HWLOCK_I2C);
+	pmic_set_led(led, value > 31 ? 31 : value);
+	hwlock_release(HWLOCK_I2C);
+}
+
+int epic_leds_get_rocket(int led)
+{
+	int ret = 0;
+
+	hwlock_acquire(HWLOCK_I2C);
+	ret = pmic_get_led(led);
+	hwlock_release(HWLOCK_I2C);
+	return ret;
+}
+
+static StaticTimer_t flash_timer_data[3];
+static TimerHandle_t flash_timer[] = { NULL, NULL, NULL };
+
+static void rocket_timer_callback(TimerHandle_t flash_timer)
+{
+	uint32_t id = (uint32_t)pvTimerGetTimerID(flash_timer);
+	epic_leds_set_rocket(id, 0);
+}
+
+void epic_leds_flash_rocket(int led, uint8_t value, int millis)
+{
+	int ticks  = millis * (configTICK_RATE_HZ / 1000);
+	int32_t id = led;
+	if (flash_timer[id] == NULL) {
+		flash_timer[id] = xTimerCreateStatic(
+			"flashtimer",
+			ticks,
+			pdFALSE,
+			(void *)id,
+			rocket_timer_callback,
+			&flash_timer_data[id]
+		);
+		epic_leds_set_rocket(led, value);
+	}
+	epic_leds_set_rocket(led, value);
+	xTimerChangePeriod(flash_timer[id], ticks, 0);
+}
+void epic_set_flashlight(bool power)
+{
+	hwlock_acquire(HWLOCK_I2C);
+	leds_flashlight(power);
+	hwlock_release(HWLOCK_I2C);
+}
+
+void epic_leds_update(void)
+{
+	do_update();
+}
+
+void epic_leds_set_powersave(bool eco)
+{
+	hwlock_acquire(HWLOCK_I2C);
+	leds_powersave(eco);
+	hwlock_release(HWLOCK_I2C);
+}
+
+void epic_leds_set_gamma_table(uint8_t rgb_channel, uint8_t *gamma_table)
+{
+	leds_set_gamma_table(rgb_channel, gamma_table);
+}
+
+void epic_leds_clear_all(uint8_t r, uint8_t g, uint8_t b)
+{
+	for (int i = 0; i < NUM_LEDS; i++) {
+		if (i == PERSONAL_STATE_LED && personal_state_enabled())
+			continue;
+
+		leds_prep(i, r, g, b);
+	}
+
+	do_update();
+}

epicardium/modules/light_sensor.c → epicardium/drivers/light_sensor.c

 #include "epicardium.h"
-#include "modules/log.h"
+#include "os/core.h"
+#include "os/work_queue.h"
 #include "modules/modules.h"
 
 #include "mxc_config.h"
@@ -27,26 +28,32 @@ static int light_sensor_init()
 	return 0;
 }
 
-static void readAdcCallback()
+uint16_t epic_light_sensor_read()
 {
-	if (hwlock_acquire(HWLOCK_ADC, 0) != 0) {
-		/* Can't do much about this here ... Retry next time */
-		return;
-	}
+	hwlock_acquire(HWLOCK_ADC);
 
 	ADC_StartConvert(ADC_CH_7, 0, 0);
 	ADC_GetData(&last_value);
 
 	hwlock_release(HWLOCK_ADC);
+	return last_value;
+}
+
+static void workpoll(void *data)
+{
+	epic_light_sensor_read();
+}
+
+static void poll(TimerHandle_t xTimer)
+{
+	workqueue_schedule(workpoll, NULL);
 }
 
 int epic_light_sensor_run()
 {
 	int ret = 0;
 
-	if (hwlock_acquire(HWLOCK_ADC, pdMS_TO_TICKS(500)) != 0) {
-		return -EBUSY;
-	}
+	hwlock_acquire(HWLOCK_ADC);
 
 	light_sensor_init();
 
@@ -56,7 +63,7 @@ int epic_light_sensor_run()
 			READ_FREQ,
 			pdTRUE,
 			NULL,
-			readAdcCallback,
+			poll,
 			&poll_timer_buffer
 		);
 		// since &poll_timer_buffer is not NULL, xTimerCreateStatic should allways succeed, so

epicardium/modules/max30001.c → epicardium/drivers/max30001.c

@@ -9,17 +9,14 @@
 
 #include "FreeRTOS.h"
 #include "task.h"
-#include "semphr.h"
 #include "queue.h"
 
-#include "api/interrupt-sender.h"
 #include "epicardium.h"
-#include "modules/log.h"
+#include "os/core.h"
 #include "modules/modules.h"
 #include "modules/stream.h"
-
-/* Ticks to wait when trying to acquire lock */
-#define LOCK_WAIT pdMS_TO_TICKS(MAX30001_MUTEX_WAIT_MS)
+#include "os/mutex.h"
+#include "user_core/interrupts.h"
 
 /* Interrupt Pin */
 static const gpio_cfg_t max30001_interrupt_pin = {
@@ -36,8 +33,7 @@ static const gpio_cfg_t analog_switch = {
 static TaskHandle_t max30001_task_id = NULL;
 
 /* MAX30001 Mutex */
-static StaticSemaphore_t max30001_mutex_data;
-static SemaphoreHandle_t max30001_mutex = NULL;
+static struct mutex max30001_mutex = { 0 };
 
 /* Stream */
 static struct stream_info max30001_stream;
@@ -54,15 +50,8 @@ int epic_max30001_enable_sensor(struct max30001_sensor_config *config)
 {
 	int result = 0;
 
-	result = hwlock_acquire(HWLOCK_SPI_ECG, pdMS_TO_TICKS(100));
-	if (result < 0) {
-		return result;
-	}
-
-	if (xSemaphoreTake(max30001_mutex, LOCK_WAIT) != pdTRUE) {
-		result = -EBUSY;
-		goto out_free_spi;
-	}
+	mutex_lock(&max30001_mutex);
+	hwlock_acquire(HWLOCK_SPI_ECG);
 
 	struct stream_info *stream = &max30001_stream;
 	;
@@ -97,9 +86,8 @@ int epic_max30001_enable_sensor(struct max30001_sensor_config *config)
 	result                 = SD_MAX30001_ECG;
 
 out_free_both:
-	xSemaphoreGive(max30001_mutex);
-out_free_spi:
 	hwlock_release(HWLOCK_SPI_ECG);
+	mutex_unlock(&max30001_mutex);
 	return result;
 }
 
@@ -107,15 +95,8 @@ int epic_max30001_disable_sensor(void)
 {
 	int result = 0;
 
-	result = hwlock_acquire(HWLOCK_SPI_ECG, pdMS_TO_TICKS(100));
-	if (result < 0) {
-		return result;
-	}
-
-	if (xSemaphoreTake(max30001_mutex, LOCK_WAIT) != pdTRUE) {
-		result = -EBUSY;
-		goto out_free_spi;
-	}
+	mutex_lock(&max30001_mutex);
+	hwlock_acquire(HWLOCK_SPI_ECG);
 
 	struct stream_info *stream = &max30001_stream;
 	result                     = stream_deregister(SD_MAX30001_ECG, stream);
@@ -134,9 +115,8 @@ int epic_max30001_disable_sensor(void)
 
 	result = 0;
 out_free_both:
-	xSemaphoreGive(max30001_mutex);
-out_free_spi:
 	hwlock_release(HWLOCK_SPI_ECG);
+	mutex_unlock(&max30001_mutex);
 	return result;
 }
 
@@ -155,16 +135,18 @@ static void max30001_handle_samples(int16_t *sensor_data, int16_t n)
 
 	while (n--) {
 		uint16_t data = -*sensor_data++;
-		if (xQueueSend(
-			    max30001_stream.queue,
-			    &data,
-			    MAX30001_MUTEX_WAIT_MS) != pdTRUE) {
-			LOG_WARN(
-				"max30001",
-				"queue full"); // TODO; handle queue full
+
+		/* Discard overflow.  See discussion in !316. */
+		if (xQueueSend(max30001_stream.queue, &data, 0) != pdTRUE) {
+			if (!max30001_stream.was_full) {
+				LOG_WARN("max30001", "queue full");
 			}
+			max30001_stream.was_full = true;
+		} else {
+			max30001_stream.was_full = false;
 		}
-	api_interrupt_trigger(EPIC_INT_MAX30001_ECG);
+	}
+	interrupt_trigger(EPIC_INT_MAX30001_ECG);
 }
 
 /***** Functions *****/
@@ -301,23 +283,16 @@ static int max30001_fetch_fifo(void)
 {
 	int result = 0;
 
-	result = hwlock_acquire(HWLOCK_SPI_ECG, pdMS_TO_TICKS(100));
-	if (result < 0) {
-		return result;
-	}
-
-	if (xSemaphoreTake(max30001_mutex, LOCK_WAIT) != pdTRUE) {
-		result = -EBUSY;
-		goto out_free_spi;
-	}
+	mutex_lock(&max30001_mutex);
+	hwlock_acquire(HWLOCK_SPI_ECG);
 
 	uint32_t ecgFIFO, readECGSamples, ETAG[32], status;
 	int16_t ecgSample[32];
-	const int EINT_STATUS_MASK       = 1 << 23;
-	const int FIFO_OVF_MASK          = 0x7;
-	const int FIFO_VALID_SAMPLE_MASK = 0x0;
-	const int FIFO_FAST_SAMPLE_MASK  = 0x1;
-	const int ETAG_BITS_MASK         = 0x7;
+	const uint32_t EINT_STATUS_MASK       = 1 << 23;
+	const uint32_t FIFO_OVF_MASK          = 0x7;
+	const uint32_t FIFO_VALID_SAMPLE_MASK = 0x0;
+	const uint32_t FIFO_FAST_SAMPLE_MASK  = 0x1;
+	const uint32_t ETAG_BITS_MASK         = 0x7;
 
 	status = ecg_read_reg(STATUS); // Read the STATUS register
 
@@ -347,9 +322,8 @@ static int max30001_fetch_fifo(void)
 		max30001_handle_samples(ecgSample, readECGSamples);
 	}
 
-	xSemaphoreGive(max30001_mutex);
-out_free_spi:
 	hwlock_release(HWLOCK_SPI_ECG);
+	mutex_unlock(&max30001_mutex);
 	return result;
 }
 
@@ -370,22 +344,17 @@ static void max300001_interrupt_callback(void *_)
 }
 /* }}} */
 
+void max30001_mutex_init(void)
+{
+	mutex_create(&max30001_mutex);
+}
+
 void vMAX30001Task(void *pvParameters)
 {
 	max30001_task_id = xTaskGetCurrentTaskHandle();
-	max30001_mutex   = xSemaphoreCreateMutexStatic(&max30001_mutex_data);
 
-	int lockret = hwlock_acquire(HWLOCK_SPI_ECG, pdMS_TO_TICKS(100));
-	if (lockret < 0) {
-		LOG_CRIT("max30001", "Failed to acquire SPI lock!");
-		vTaskDelay(portMAX_DELAY);
-	}
-
-	/* Take Mutex during initialization, just in case */
-	if (xSemaphoreTake(max30001_mutex, 0) != pdTRUE) {
-		LOG_CRIT("max30001", "Failed to acquire MAX30001 mutex!");
-		vTaskDelay(portMAX_DELAY);
-	}
+	mutex_lock(&max30001_mutex);
+	hwlock_acquire(HWLOCK_SPI_ECG);
 
 	/* Install interrupt callback */
 	GPIO_Config(&max30001_interrupt_pin);
@@ -406,20 +375,15 @@ void vMAX30001Task(void *pvParameters)
 	GPIO_Config(&analog_switch);
 	GPIO_OutClr(&analog_switch); // Wrist
 
-	xSemaphoreGive(max30001_mutex);
 	hwlock_release(HWLOCK_SPI_ECG);
+	mutex_unlock(&max30001_mutex);
 
 	/* ----------------------------------------- */
 
 	while (1) {
 		if (max30001_sensor_active) {
 			int ret = max30001_fetch_fifo();
-			if (ret == -EBUSY) {
-				LOG_WARN(
-					"max30001", "Could not acquire mutex?"
-				);
-				continue;
-			} else if (ret < 0) {
+			if (ret < 0) {
 				LOG_ERR("max30001", "Unknown error: %d", -ret);
 			}
 		}

epicardium/drivers/max86150.c

+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include "max86150.h"
+#include "epicardium.h"
+#include "os/core.h"
+#include "modules/stream.h"
+#include "gpio.h"
+#include "pmic.h"
+#include "user_core/interrupts.h"
+
+#include "FreeRTOS.h"
+#include "task.h"
+#include "queue.h"
+
+#include "modules/modules.h"
+
+static const gpio_cfg_t max86150_interrupt_pin = {
+	PORT_1, PIN_13, GPIO_FUNC_IN, GPIO_PAD_PULL_UP
+};
+
+/* MAX86150 Task ID */
+static TaskHandle_t max86150_task_id = NULL;
+
+/* MAX86150 Mutex */
+static struct mutex max86150_mutex = { 0 };
+
+/* Stream */
+static struct stream_info max86150_stream;
+
+/* Active */
+static bool max86150_sensor_active = false;
+
+int epic_max86150_enable_sensor(
+	struct max86150_sensor_config *config, size_t config_size
+) {
+	int result = 0;
+
+	if (sizeof(struct max86150_sensor_config) != config_size) {
+		return -EINVAL;
+	}
+
+	mutex_lock(&max86150_mutex);
+	hwlock_acquire(HWLOCK_I2C);
+
+	struct stream_info *stream = &max86150_stream;
+	stream->item_size          = sizeof(struct max86150_sensor_data);
+	stream->queue =
+		xQueueCreate(config->sample_buffer_len, stream->item_size);
+	if (stream->queue == NULL) {
+		result = -ENOMEM;
+		goto out_free;
+	}
+
+	uint8_t ppg_sample_rate;
+
+	if (config->ppg_sample_rate == 10) {
+		ppg_sample_rate = MAX86150_PPG_SAMPLERATE_10;
+	} else if (config->ppg_sample_rate == 20) {
+		ppg_sample_rate = MAX86150_PPG_SAMPLERATE_20;
+	} else if (config->ppg_sample_rate == 50) {
+		ppg_sample_rate = MAX86150_PPG_SAMPLERATE_50;
+	} else if (config->ppg_sample_rate == 84) {
+		ppg_sample_rate = MAX86150_PPG_SAMPLERATE_84;
+	} else if (config->ppg_sample_rate == 100) {
+		ppg_sample_rate = MAX86150_PPG_SAMPLERATE_100;
+	} else if (config->ppg_sample_rate == 200) {
+		ppg_sample_rate = MAX86150_PPG_SAMPLERATE_200;
+	} else if (config->ppg_sample_rate == 400) {
+		ppg_sample_rate = MAX86150_PPG_SAMPLERATE_400;
+	} else {
+		result = -EINVAL;
+		goto out_free;
+	}
+
+	result = stream_register(SD_MAX86150, stream);
+	if (result < 0) {
+		vQueueDelete(stream->queue);
+		goto out_free;
+	}
+
+	bool begin_result = max86150_begin();
+	if (!begin_result) {
+		result = -ENODEV;
+		vQueueDelete(stream->queue);
+		goto out_free;
+	}
+
+	max86150_setup(ppg_sample_rate);
+	max86150_get_int1();
+	max86150_get_int2();
+
+	max86150_sensor_active = true;
+	result                 = SD_MAX86150;
+
+out_free:
+	hwlock_release(HWLOCK_I2C);
+	mutex_unlock(&max86150_mutex);
+	return result;
+}
+
+int epic_max86150_disable_sensor(void)
+{
+	int result = 0;
+
+	mutex_lock(&max86150_mutex);
+	hwlock_acquire(HWLOCK_I2C);
+
+	max86150_shut_down();
+	max86150_sensor_active = false;
+
+	struct stream_info *stream = &max86150_stream;
+	result                     = stream_deregister(SD_MAX86150, stream);
+	if (result == 0) {
+		vQueueDelete(stream->queue);
+		stream->queue = NULL;
+	}
+
+	hwlock_release(HWLOCK_I2C);
+	mutex_unlock(&max86150_mutex);
+	return result;
+}
+
+static int max86150_handle_sample(struct max86150_sensor_data *data)
+{
+	//LOG_INFO("max86150", "Sample! %ld, %ld, %ld", data->red, data->ir, data->ecg);
+
+	if (max86150_stream.queue == NULL) {
+		return -ESRCH;
+	}
+
+	/* Discard overflow.  See discussion in !316. */
+	if (xQueueSend(max86150_stream.queue, data, 0) != pdTRUE) {
+		if (!max86150_stream.was_full) {
+			LOG_WARN("max86150", "queue full");
+		}
+		max86150_stream.was_full = true;
+	} else {
+		max86150_stream.was_full = false;
+	}
+
+	return 0;
+}
+
+static int max86150_fetch_fifo(void)
+{
+	int result = 0;
+
+	mutex_lock(&max86150_mutex);
+	hwlock_acquire(HWLOCK_I2C);
+
+	struct max86150_sensor_data sample;
+
+	// There is a recommendation from Maxim not to read the entire FIFO, but rather a fixed number of samples.
+	// See https://os.mbed.com/users/laserdad/code/MAX86150_ECG_PPG//file/3c728f3d1f10/main.cpp/
+	// So we should not use max86150_check() but max86150_get_sample().
+	int n = 0;
+	while (max86150_get_sample(&sample.red, &sample.ir, &sample.ecg) > 0) {
+		n++;
+		result = max86150_handle_sample(&sample);
+		// stop in case of errors
+		if (result < 0) {
+			n = 0;
+			break;
+		}
+	}
+	hwlock_release(HWLOCK_I2C);
+	mutex_unlock(&max86150_mutex);
+
+	if (n > 0) {
+		interrupt_trigger(EPIC_INT_MAX86150);
+	}
+	//LOG_INFO("max86150", "%d", n);
+	return result;
+}
+
+/*
+ * Callback for the MAX86150 interrupt pin.  This callback is called from the
+ * SDK's GPIO interrupt driver, in interrupt context.
+ */
+static void max86150_interrupt_callback(void *_)
+{
+	BaseType_t xHigherPriorityTaskWoken = pdFALSE;
+
+	if (max86150_task_id != NULL) {
+		vTaskNotifyGiveFromISR(
+			max86150_task_id, &xHigherPriorityTaskWoken
+		);
+		portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
+	}
+}
+/* }}} */
+
+void max86150_mutex_init(void)
+{
+	mutex_create(&max86150_mutex);
+}
+
+void vMAX86150Task(void *pvParameters)
+{
+	max86150_task_id = xTaskGetCurrentTaskHandle();
+
+	mutex_lock(&max86150_mutex);
+	hwlock_acquire(HWLOCK_I2C);
+
+	/* Install interrupt callback */
+	GPIO_Config(&max86150_interrupt_pin);
+	GPIO_RegisterCallback(
+		&max86150_interrupt_pin, max86150_interrupt_callback, NULL
+	);
+	GPIO_IntConfig(
+		&max86150_interrupt_pin, GPIO_INT_EDGE, GPIO_INT_FALLING
+	);
+	GPIO_IntEnable(&max86150_interrupt_pin);
+	NVIC_SetPriority(
+		(IRQn_Type)MXC_GPIO_GET_IRQ(max86150_interrupt_pin.port), 2
+	);
+	NVIC_EnableIRQ(
+		(IRQn_Type)MXC_GPIO_GET_IRQ(max86150_interrupt_pin.port)
+	);
+
+	hwlock_release(HWLOCK_I2C);
+	mutex_unlock(&max86150_mutex);
+
+	/* ----------------------------------------- */
+
+	while (1) {
+		if (max86150_sensor_active) {
+			//LOG_INFO("max86150", "Interrupt!");
+			mutex_lock(&max86150_mutex);
+			hwlock_acquire(HWLOCK_I2C);
+
+			int i1 = max86150_get_int1();
+
+			hwlock_release(HWLOCK_I2C);
+			mutex_unlock(&max86150_mutex);
+
+			//LOG_INFO("max86150", "%d", i1);
+
+			if (i1 & 16) {
+				interrupt_trigger(EPIC_INT_MAX86150_PROX);
+			}
+
+			int ret = max86150_fetch_fifo();
+			if (ret < 0) {
+				LOG_ERR("max86150", "Unknown error: %d", -ret);
+			}
+		}
+		/*
+		 * Wait for interrupt.  After two seconds, fetch FIFO anyway
+		 *
+		 * In the future, reads using epic_stream_read() might also
+		 * trigger a FIFO fetch, from outside this task.
+		 */
+		ulTaskNotifyTake(pdTRUE, pdMS_TO_TICKS(2000));
+	}
+}

epicardium/drivers/meson.build

+driver_sources = files(
+  'bhi.c',
+  'bsec.c',
+  'bme680.c',
+  'buttons.c',
+  'gpio.c',
+  'leds.c',
+  'light_sensor.c',
+  'max86150.c',
+  'max30001.c',
+  'pmic.c',
+  'rtc.c',
+  'serial.c',
+  'sleep.c',
+  'rng.c',
+  'usb.c',
+  'vibra.c',
+  'watchdog.c',
+  'ws2812.c',
+
+  'display/lcd.c',
+  'display/api.c',
+  'display/init.c',
+)

epicardium/drivers/pmic.c

+#include "epicardium.h"
+#include "modules/modules.h"
+#include "drivers/drivers.h"
+#include "os/core.h"
+#include "os/config.h"
+#include "user_core/user_core.h"
+
+#include "card10.h"
+#include "pmic.h"
+#include "MAX77650-Arduino-Library.h"
+
+#include "max32665.h"
+#include "mxc_sys.h"
+#include "mxc_pins.h"
+#include "adc.h"
+
+#include "FreeRTOS.h"
+#include "task.h"
+#include "timers.h"
+
+#include <stdio.h>
+#include <string.h>
+
+/* Task ID for the pmic handler */
+static TaskHandle_t pmic_task_id = NULL;
+
+enum {
+	/* An irq was received, probably the power button */
+	PMIC_NOTIFY_IRQ = 1,
+	/* The timer has ticked and we should check the battery voltage again */
+	PMIC_NOTIFY_MONITOR = 2,
+};
+
+void pmic_interrupt_callback(void *_)
+{
+	BaseType_t xHigherPriorityTaskWoken = pdFALSE;
+	if (pmic_task_id != NULL) {
+		xTaskNotifyFromISR(
+			pmic_task_id,
+			PMIC_NOTIFY_IRQ,
+			eSetBits,
+			&xHigherPriorityTaskWoken
+		);
+		portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
+	}
+}
+
+int pmic_read_amux(enum pmic_amux_signal sig, float *result)
+{
+	int ret = 0;
+
+	if (sig > _PMIC_AMUX_MAX) {
+		return -EINVAL;
+	}
+
+	hwlock_acquire(HWLOCK_ADC);
+	hwlock_acquire(HWLOCK_I2C);
+
+	/* Select the correct channel for this measurement.  */
+	MAX77650_setMUX_SEL(sig);
+
+	/*
+	 * According to the datasheet, the voltage will stabilize within 0.3us.
+	 * Just to be sure, we'll wait a little longer.  In the meantime,
+	 * release the I2C mutex.
+	 */
+	hwlock_release(HWLOCK_I2C);
+
+	vTaskDelay(pdMS_TO_TICKS(5));
+	hwlock_acquire(HWLOCK_I2C);
+
+	uint16_t adc_data;
+	ADC_StartConvert(ADC_CH_0, 0, 0);
+	ADC_GetData(&adc_data);
+
+	/* Turn MUX back to neutral so it does not waste power.  */
+	MAX77650_setMUX_SEL(PMIC_AMUX_DISABLED);
+
+	/* Convert ADC measurement to SI Volts */
+	float adc_voltage = (float)adc_data / 1023.0f * 1.22f;
+
+	/*
+	 * Convert value according to PMIC formulas (Table 7)
+	 */
+	switch (sig) {
+	case PMIC_AMUX_CHGIN_U:
+		*result = adc_voltage / 0.167f;
+		break;
+	case PMIC_AMUX_CHGIN_I:
+		*result = adc_voltage / 2.632f;
+		break;
+	case PMIC_AMUX_BATT_U:
+		*result = adc_voltage / 0.272f;
+		break;
+	case PMIC_AMUX_BATT_CHG_I:
+		*result = adc_voltage / 1.25f;
+		break;
+	case PMIC_AMUX_BATT_NULL_I:
+	case PMIC_AMUX_THM_U:
+	case PMIC_AMUX_TBIAS_U:
+	case PMIC_AMUX_AGND_U:
+		*result = adc_voltage;
+		break;
+	case PMIC_AMUX_SYS_U:
+		*result = adc_voltage / 0.26f;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	hwlock_release(HWLOCK_I2C);
+	hwlock_release(HWLOCK_ADC);
+
+	return ret;
+}
+
+/*
+ * Read the interrupt flag register and handle all interrupts which the PMIC has
+ * sent.  In most cases this will be the buttons.
+ */
+static uint8_t pmic_poll_interrupts(void)
+{
+	hwlock_acquire(HWLOCK_I2C);
+
+	uint8_t int_flag = MAX77650_getINT_GLBL();
+	hwlock_release(HWLOCK_I2C);
+
+	/* TODO: Remove when all interrupts are handled */
+	if (int_flag & ~(MAX77650_INT_nEN_F | MAX77650_INT_nEN_R)) {
+		LOG_WARN("pmic", "Unhandled PMIC Interrupt: %x", int_flag);
+	}
+
+	return int_flag;
+}
+
+__attribute__((noreturn)) static void pmic_die(float u_batt)
+{
+	/* Stop core 1 */
+	core1_stop();
+
+	/* Grab the screen */
+	disp_forcelock();
+
+	/* Turn it on in case it was off */
+	epic_disp_backlight(100);
+
+	/* Draw an error screen */
+	epic_disp_clear(0x0000);
+
+	epic_disp_print(0, 0, " Battery", 0xffff, 0x0000);
+	epic_disp_print(0, 20, " critical", 0xffff, 0x0000);
+	epic_disp_print(0, 40, "  !!!!", 0xffff, 0x0000);
+	epic_disp_update();
+
+	/* Vibrate violently */
+	epic_vibra_set(true);
+
+	/* Wait a bit */
+	for (int i = 0; i < 50000000; i++)
+		__NOP();
+
+	/* We have some of headroom to keep the RTC going.
+	 * The battery protection circuit will shut down
+	 * the system at 3.0 V */
+
+	/* TODO: Wake-up when USB is attached again */
+	sleep_deepsleep();
+	card10_reset();
+}
+
+/*
+ * Check the battery voltage.  If it drops too low, turn card10 off.
+ */
+static void pmic_check_battery()
+{
+	float u_batt;
+	int res;
+
+	/**
+	 * 0 = uncertain, ask config
+	 * 1 = disabled
+	 * 2 = enabled
+	 */
+	static int pmic_do_battery_check = 0;
+
+	if (pmic_do_battery_check == 0) {
+		if (config_get_boolean_with_default("battery_check", true)) {
+			pmic_do_battery_check = 2;
+		} else {
+			pmic_do_battery_check = 1;
+			LOG_WARN(
+				"pmic",
+				"Battery check was disabled by config!"
+			);
+		}
+	}
+
+	if (pmic_do_battery_check == 1) {
+		/* Disabled, ignore */
+		return;
+	}
+
+	res = pmic_read_amux(PMIC_AMUX_BATT_U, &u_batt);
+	if (res < 0) {
+		LOG_ERR("pmic",
+			"Failed reading battery voltage: %s (%d)",
+			strerror(-res),
+			res);
+		return;
+	}
+
+	LOG_DEBUG(
+		"pmic",
+		"Battery is at %d.%03d V",
+		(int)u_batt,
+		(int)(u_batt * 1000.0) % 1000
+	);
+
+	if (u_batt < BATTERY_CRITICAL) {
+		pmic_die(u_batt);
+	}
+}
+
+/*
+ * API-call for battery voltage
+ */
+int epic_read_battery_voltage(float *result)
+{
+	return pmic_read_amux(PMIC_AMUX_BATT_U, result);
+}
+
+/*
+ * API-call for battery current
+ */
+int epic_read_battery_current(float *result)
+{
+	return pmic_read_amux(PMIC_AMUX_BATT_CHG_I, result);
+}
+
+/*
+ * API-call for charge voltage
+ */
+int epic_read_chargein_voltage(float *result)
+{
+	return pmic_read_amux(PMIC_AMUX_CHGIN_U, result);
+}
+
+/*
+ * API-call for charge voltage
+ */
+int epic_read_chargein_current(float *result)
+{
+	return pmic_read_amux(PMIC_AMUX_BATT_CHG_I, result);
+}
+
+/*
+ * API-call for system voltage
+ */
+int epic_read_system_voltage(float *result)
+{
+	return pmic_read_amux(PMIC_AMUX_SYS_U, result);
+}
+
+/*
+ * API-call for thermistor voltage
+ *
+ * Thermistor is as 10k at room temperature,
+ * voltage divided with another 10k.
+ * (50% V_bias at room temperature)
+ */
+int epic_read_thermistor_voltage(float *result)
+{
+	return pmic_read_amux(PMIC_AMUX_THM_U, result);
+}
+
+static StaticTimer_t pmic_timer_data;
+static void vPmicTimerCb(TimerHandle_t xTimer)
+{
+	/*
+	 * Tell the PMIC task to check the battery again.
+	 */
+	xTaskNotify(pmic_task_id, PMIC_NOTIFY_MONITOR, eSetBits);
+}
+
+void vPmicTask(void *pvParameters)
+{
+	pmic_task_id       = xTaskGetCurrentTaskHandle();
+	uint8_t interrupts = 0;
+	uint32_t reason    = 0;
+
+	ADC_Init(0x9, NULL);
+	GPIO_Config(&gpio_cfg_adc0);
+
+	TickType_t button_start_tick = 0;
+
+	pmic_check_battery();
+
+	TimerHandle_t pmic_timer = xTimerCreateStatic(
+		"PMIC Timer",
+		pdMS_TO_TICKS(60 * 1000),
+		pdTRUE,
+		NULL,
+		vPmicTimerCb,
+		&pmic_timer_data
+	);
+	if (pmic_timer == NULL) {
+		LOG_CRIT("pmic", "Could not create timer.");
+		vTaskDelay(portMAX_DELAY);
+	}
+	xTimerStart(pmic_timer, 0);
+
+	/* Clear all pending interrupts. */
+	pmic_poll_interrupts();
+
+	while (1) {
+		interrupts |= pmic_poll_interrupts();
+		if (interrupts == 0) {
+			reason |= ulTaskNotifyTake(pdTRUE, portMAX_DELAY);
+		}
+
+		/* New interrupts */
+		if (reason & PMIC_NOTIFY_IRQ) {
+			reason ^= PMIC_NOTIFY_IRQ;
+			interrupts |= pmic_poll_interrupts();
+		}
+
+		if (interrupts & MAX77650_INT_nEN_R) {
+			/* Ignored in this state */
+			/* This can happen if the button is pressed
+			 * during boot and released now. */
+			interrupts ^= MAX77650_INT_nEN_R; /* Mark as handled. */
+		}
+
+		if (interrupts & MAX77650_INT_nEN_F) {
+			/* Button was pressed */
+			interrupts ^= MAX77650_INT_nEN_F; /* Mark as handled. */
+
+			button_start_tick = xTaskGetTickCount();
+			while (true) {
+				TickType_t duration =
+					xTaskGetTickCount() - button_start_tick;
+
+				if (duration > pdMS_TO_TICKS(1000)) {
+					disp_forcelock();
+					disp_ctx_reinit();
+
+					/* Turn it on in case it was off */
+					epic_disp_backlight(100);
+
+					epic_disp_clear(0x0000);
+
+					char buf[20];
+					sprintf(buf,
+						"Off in %d",
+						7 - (int)(duration + 500) /
+								1000);
+					epic_disp_print(
+						0,
+						0,
+						"Sleep zZz..",
+						0xffff,
+						0x0000
+					);
+					epic_disp_print(
+						0, 25, buf, 0xf000, 0x0000
+					);
+					epic_disp_print(
+						0,
+						50,
+						"   Reset ->",
+						0xffff,
+						0x0000
+					);
+					epic_disp_update();
+				}
+
+				if (duration >= pdMS_TO_TICKS(1000)) {
+					if (epic_buttons_read(
+						    BUTTON_RIGHT_TOP)) {
+						disp_forcelock();
+						disp_ctx_reinit();
+
+						/* Turn it on in case it was off */
+						epic_disp_backlight(100);
+
+						epic_disp_clear(0x0000);
+						epic_disp_print(
+							55,
+							30,
+							"Reset!",
+							0xf800,
+							0x0000
+						);
+						epic_disp_update();
+
+						serial_return_to_synchronous();
+						LOG_WARN(
+							"pmic",
+							"Resetting ..."
+						);
+						card10_reset();
+					}
+				}
+
+				if (interrupts & MAX77650_INT_nEN_R) {
+					/* Button is released */
+					interrupts ^=
+						MAX77650_INT_nEN_R; /* Mark as handled. */
+
+					if (duration < pdMS_TO_TICKS(1000)) {
+						return_to_menu();
+					}
+
+					if (duration > pdMS_TO_TICKS(1000)) {
+						serial_return_to_synchronous();
+						LOG_WARN("pmic", "Poweroff");
+						sleep_deepsleep();
+						card10_reset();
+					}
+					break;
+				}
+
+				reason |= ulTaskNotifyTake(
+					pdTRUE, pdMS_TO_TICKS(200)
+				);
+				if (reason & PMIC_NOTIFY_IRQ) {
+					/* New interrupts */
+					reason ^= PMIC_NOTIFY_IRQ;
+					interrupts |= pmic_poll_interrupts();
+				}
+			}
+		}
+
+		if (reason & PMIC_NOTIFY_MONITOR) {
+			reason ^= PMIC_NOTIFY_MONITOR;
+			pmic_check_battery();
+		}
+	}
+}

epicardium/drivers/rng.c

+#include "epicardium.h"
+#include "modules/modules.h"
+#include "drivers/drivers.h"
+
+#include "MAX77650-Arduino-Library.h"
+#include "tiny-AES-c/aes.h"
+#include "SHA256/mark2/sha256.h"
+
+#include "mxc_sys.h"
+#include "adc.h"
+#include "mxc_delay.h"
+#include "rtc.h"
+#include "trng.h"
+
+#include <string.h>
+
+static struct AES_ctx aes_ctx;
+
+int epic_trng_read(uint8_t *dest, size_t size)
+{
+	if (dest == NULL)
+		return -EFAULT;
+
+	TRNG_Init(NULL);
+	TRNG_Read(MXC_TRNG, dest, size);
+
+	return 0;
+}
+
+int epic_csprng_read(uint8_t *dest, size_t size)
+{
+	if (size >= AES_BLOCKLEN) {
+		int block_count = size / AES_BLOCKLEN;
+		AES_CTR_xcrypt_buffer(
+			&aes_ctx, dest, block_count * AES_BLOCKLEN
+		);
+		size -= block_count * AES_BLOCKLEN;
+		dest += block_count * AES_BLOCKLEN;
+	}
+
+	if (size > 0) {
+		uint8_t out[AES_BLOCKLEN];
+		AES_CTR_xcrypt_buffer(&aes_ctx, out, sizeof(out));
+		memcpy(dest, out, size);
+	}
+
+	return 0;
+}
+
+void rng_init(void)
+{
+	uint8_t key[AES_BLOCKLEN];
+	uint8_t iv[AES_BLOCKLEN];
+	uint8_t hash[32];
+	sha256_context ctx;
+	int i;
+
+	sha256_init(&ctx);
+
+	/* Seed from TRNG.
+	 * Takes about 10 ms. */
+	for (i = 0; i < 256; i++) {
+		uint8_t entropy[AES_BLOCKLEN];
+		epic_trng_read(entropy, AES_BLOCKLEN);
+		sha256_hash(&ctx, entropy, AES_BLOCKLEN);
+	}
+
+	// Seed from RTC
+	uint32_t sec, subsec;
+	while (RTC_GetTime(&sec, &subsec) == E_BUSY) {
+		mxc_delay(4000);
+	}
+	sha256_hash(&ctx, &sec, sizeof(sec));
+	sha256_hash(&ctx, &subsec, sizeof(subsec));
+
+	// Seed from SysTick
+	uint32_t systick = SysTick->VAL;
+	sha256_hash(&ctx, &systick, sizeof(systick));
+
+	/* Seed from ADC.
+	 * Takes about 50 ms */
+	ADC_Init(0x9, NULL);
+	GPIO_Config(&gpio_cfg_adc0);
+	MAX77650_setMUX_SEL(PMIC_AMUX_BATT_U);
+	for (i = 0; i < 256; i++) {
+		uint16_t adc_data;
+		ADC_StartConvert(ADC_CH_0, 0, 0);
+		ADC_GetData(&adc_data);
+		sha256_hash(&ctx, &adc_data, sizeof(adc_data));
+	}
+	MAX77650_setMUX_SEL(PMIC_AMUX_DISABLED);
+
+	sha256_done(&ctx, hash);
+	memcpy(key, hash, AES_BLOCKLEN);
+	memcpy(iv, hash + AES_BLOCKLEN, AES_BLOCKLEN);
+	AES_init_ctx_iv(&aes_ctx, key, iv);
+}

epicardium/drivers/rtc.c

+#include "epicardium.h"
+#include "os/core.h"
+#include "modules/modules.h"
+#include "user_core/interrupts.h"
+
+#include "FreeRTOS.h"
+#include "task.h"
+
+#include "rtc.h"
+
+#include <stdint.h>
+
+uint64_t monotonic_offset = 0;
+
+uint32_t epic_rtc_get_monotonic_seconds(void)
+{
+	return epic_rtc_get_seconds() + monotonic_offset / 1000ULL;
+}
+
+uint64_t epic_rtc_get_monotonic_milliseconds(void)
+{
+	return epic_rtc_get_milliseconds() + monotonic_offset;
+}
+
+uint32_t epic_rtc_get_seconds(void)
+{
+	uint32_t sec, subsec;
+
+	/*
+	 * TODO:  Find out what causes the weird behavior of this function.  The
+	 *        time needed for this call seems to depend on the frequency at
+	 *        which it is called.
+	 */
+	while (RTC_GetTime(&sec, &subsec) == E_BUSY) {
+		vTaskDelay(pdMS_TO_TICKS(4));
+	}
+
+	return sec;
+}
+
+uint64_t epic_rtc_get_milliseconds(void)
+{
+	uint32_t sec, subsec;
+
+	while (RTC_GetTime(&sec, &subsec) == E_BUSY) {
+		vTaskDelay(pdMS_TO_TICKS(4));
+	}
+
+	// Without the bias of 999 (0.24 milliseconds), this decoding function is
+	// numerically unstable:
+	//
+	// Encoding 5 milliseconds into 20 subsecs (using the encoding function in
+	// epic_rtc_set_milliseconds) and decoding it without the bias of 999 yields
+	// 4 milliseconds.
+	//
+	// The following invariants should hold when encoding / decoding from and to
+	// milliseconds / subseconds:
+	//
+	// - 0 <= encode(ms) < 4096 for 0 <= ms < 1000
+	// - decode(encode(ms)) == ms for 0 <= ms < 1000
+	// - 0 <= decode(subsec) < 1000 for 0 <= subsec < 4096
+	//
+	// These invariants were proven experimentally.
+	return (subsec * 1000ULL + 999ULL) / 4096 + sec * 1000ULL;
+}
+
+void epic_rtc_set_milliseconds(uint64_t milliseconds)
+{
+	uint32_t sec, subsec;
+	uint64_t old_milliseconds, diff;
+
+	old_milliseconds = epic_rtc_get_milliseconds();
+
+	sec    = milliseconds / 1000;
+	subsec = (milliseconds % 1000);
+	subsec *= 4096;
+	subsec /= 1000;
+
+	while (RTC_Init(MXC_RTC, sec, subsec, NULL) == E_BUSY)
+		;
+	while (RTC_EnableRTCE(MXC_RTC) == E_BUSY)
+		;
+
+	diff = old_milliseconds - milliseconds;
+	monotonic_offset += diff;
+}
+
+/* We need to use interrupt_trigger_unsafe() here */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+void RTC_IRQHandler(void)
+{
+	int flags = RTC_GetFlags();
+
+	if (flags & MXC_F_RTC_CTRL_ALDF) {
+		RTC_ClearFlags(MXC_F_RTC_CTRL_ALDF);
+		interrupt_trigger_unsafe(EPIC_INT_RTC_ALARM);
+	} else {
+		LOG_WARN("rtc", "Unknown IRQ caught!");
+		/* Disable IRQ so it does not retrigger */
+		NVIC_DisableIRQ(RTC_IRQn);
+	}
+}
+#pragma GCC diagnostic pop
+
+int epic_rtc_schedule_alarm(uint32_t timestamp)
+{
+	int res;
+
+	/*
+	 * Check if the timestamp lies in the past and if so, trigger
+	 * immediately.
+	 */
+	if (epic_rtc_get_seconds() >= timestamp) {
+		interrupt_trigger(EPIC_INT_RTC_ALARM);
+		return 0;
+	}
+
+	NVIC_EnableIRQ(RTC_IRQn);
+
+	while ((res = RTC_SetTimeofdayAlarm(MXC_RTC, timestamp)) == E_BUSY)
+		;
+
+	if (res != E_SUCCESS) {
+		return -EINVAL;
+	}
+
+	return 0;
+}

epicardium/drivers/serial.c

+#include "epicardium.h"
+#include "os/core.h"
+#include "modules/modules.h"
+#include "drivers/drivers.h"
+#include "user_core/interrupts.h"
+
+#include "max32665.h"
+#include "usb/cdcacm.h"
+#include "uart.h"
+
+#include "FreeRTOS.h"
+#include "task.h"
+#include "queue.h"
+#include "stream_buffer.h"
+
+#include <stdint.h>
+#include <stdio.h>
+
+/* The serial console in use (UART0) */
+extern mxc_uart_regs_t *ConsoleUart;
+
+/* Task ID for the serial handler */
+TaskHandle_t serial_task_id = NULL;
+
+/* Read queue, filled by both UART and CDCACM */
+static QueueHandle_t read_queue;
+/* Stream Buffer for handling all writes to serial */
+static StreamBufferHandle_t write_stream_buffer = NULL;
+
+void serial_init()
+{
+	/* Setup read queue */
+	static uint8_t buffer[sizeof(char) * SERIAL_READ_BUFFER_SIZE];
+	static StaticQueue_t read_queue_data;
+	read_queue = xQueueCreateStatic(
+		SERIAL_READ_BUFFER_SIZE, sizeof(char), buffer, &read_queue_data
+	);
+
+	/* Setup write queue */
+	static uint8_t ucWrite_stream_buffer[SERIAL_WRITE_STREAM_BUFFER_SIZE];
+	static StaticStreamBuffer_t xStream_buffer_struct;
+	write_stream_buffer = xStreamBufferCreateStatic(
+		sizeof(ucWrite_stream_buffer),
+		1,
+		ucWrite_stream_buffer,
+		&xStream_buffer_struct
+	);
+}
+
+void serial_return_to_synchronous()
+{
+	write_stream_buffer = NULL;
+}
+
+static void write_str_(const char *str, size_t length)
+{
+	if (length == 0) {
+		return;
+	}
+
+	/*
+	 * Check if the stream buffer is even initialized yet
+	 */
+	if (write_stream_buffer == NULL) {
+		UART_Write(ConsoleUart, (uint8_t *)str, length);
+		cdcacm_write((uint8_t *)str, length);
+		return;
+	}
+
+	if (xPortIsInsideInterrupt()) {
+		BaseType_t resched1 = pdFALSE;
+		BaseType_t resched2 = pdFALSE;
+
+		/*
+		 * Enter a critial section so no other task can write to the
+		 * stream buffer.
+		 */
+		uint32_t basepri = __get_BASEPRI();
+		taskENTER_CRITICAL_FROM_ISR();
+
+		xStreamBufferSendFromISR(
+			write_stream_buffer, str, length, &resched1
+		);
+
+		taskEXIT_CRITICAL_FROM_ISR(basepri);
+
+		if (serial_task_id != NULL) {
+			xTaskNotifyFromISR(
+				serial_task_id,
+				SERIAL_WRITE_NOTIFY,
+				eSetBits,
+				&resched2
+			);
+		}
+
+		/* Yield if this write woke up a higher priority task */
+		portYIELD_FROM_ISR(resched1 || resched2);
+	} else {
+		size_t bytes_sent = 0;
+		size_t index      = 0;
+		do {
+			taskENTER_CRITICAL();
+			/*
+			 * Wait time needs to be zero, because we are in a
+			 * critical section.
+			 */
+			bytes_sent = xStreamBufferSend(
+				write_stream_buffer,
+				&str[index],
+				length - index,
+				0
+			);
+			index += bytes_sent;
+			taskEXIT_CRITICAL();
+			if (serial_task_id != NULL) {
+				xTaskNotify(
+					serial_task_id,
+					SERIAL_WRITE_NOTIFY,
+					eSetBits
+				);
+				if (bytes_sent == 0) {
+					vTaskDelay(1);
+				} else {
+					portYIELD();
+				}
+			}
+		} while (index < length);
+	}
+}
+
+/*
+ * API-call to write a string.  Output goes to CDCACM, UART and BLE
+ *
+ * This is user data from core 1.
+ */
+void epic_uart_write_str(const char *str, size_t length)
+{
+	/* Make sure that we are not in an interrupt when talking to BLE.
+	 * Should not be the case if this is called from core 1
+	 * anyways. */
+	if (!xPortIsInsideInterrupt()) {
+		ble_uart_write((uint8_t *)str, length);
+	}
+	write_str_(str, length);
+}
+
+static void serial_flush_from_isr(void)
+{
+	uint8_t rx_data[32];
+	size_t received_bytes;
+
+	BaseType_t resched = pdFALSE;
+	BaseType_t woken   = pdFALSE;
+
+	uint32_t basepri = __get_BASEPRI();
+	taskENTER_CRITICAL_FROM_ISR();
+
+	do {
+		received_bytes = xStreamBufferReceiveFromISR(
+			write_stream_buffer,
+			(void *)rx_data,
+			sizeof(rx_data),
+			&woken
+		);
+		resched |= woken;
+
+		if (received_bytes == 0) {
+			break;
+		}
+
+		/*
+		 * The SDK-driver for UART is not reentrant
+		 * which means we need to perform UART writes
+		 * in a critical section.
+		 */
+
+		UART_Write(ConsoleUart, (uint8_t *)&rx_data, received_bytes);
+	} while (received_bytes > 0);
+
+	taskEXIT_CRITICAL_FROM_ISR(basepri);
+
+	portYIELD_FROM_ISR(resched);
+}
+
+static void serial_flush_from_thread(void)
+{
+	uint8_t rx_data[32];
+	size_t received_bytes;
+
+	do {
+		taskENTER_CRITICAL();
+		received_bytes = xStreamBufferReceive(
+			write_stream_buffer,
+			(void *)rx_data,
+			sizeof(rx_data),
+			0
+		);
+		taskEXIT_CRITICAL();
+
+		if (received_bytes == 0) {
+			break;
+		}
+
+		/*
+		 * The SDK-driver for UART is not reentrant
+		 * which means we need to perform UART writes
+		 * in a critical section.
+		 */
+		taskENTER_CRITICAL();
+		UART_Write(ConsoleUart, (uint8_t *)&rx_data, received_bytes);
+		taskEXIT_CRITICAL();
+
+		cdcacm_write((uint8_t *)&rx_data, received_bytes);
+	} while (received_bytes > 0);
+}
+
+/*
+ * Flush all characters which are currently waiting to be printed.
+ *
+ * If this function is called from an ISR, it will only flush to hardware UART
+ * while a call from thread mode will flush to UART, CDC-ACM, and BLE Serial.
+ */
+void serial_flush(void)
+{
+	if (xPortIsInsideInterrupt()) {
+		serial_flush_from_isr();
+	} else {
+		serial_flush_from_thread();
+	}
+}
+
+/*
+ * API-call to read a character from the queue.
+ */
+int epic_uart_read_char(void)
+{
+	char chr;
+	if (xQueueReceive(read_queue, &chr, 0) == pdTRUE) {
+		return (int)chr;
+	}
+	return (-1);
+}
+
+/*
+ * API-call to read data from the queue.
+ */
+int epic_uart_read_str(char *buf, size_t cnt)
+{
+	size_t i = 0;
+
+	for (i = 0; i < cnt; i++) {
+		if (xQueueReceive(read_queue, &buf[i], 0) != pdTRUE) {
+			break;
+		}
+	}
+
+	return i;
+}
+
+/*
+ * Write a string from epicardium. Output goes to CDCACM and UART
+ *
+ * This mainly log data from epicardium, not user date from core 1.
+ */
+long _write_epicardium(int fd, const char *buf, size_t cnt)
+{
+	/*
+	 * Only print one line at a time.  Insert `\r` between lines so they are
+	 * properly displayed on the serial console.
+	 */
+	size_t i, last = 0;
+	for (i = 0; i < cnt; i++) {
+		if (buf[i] == '\n') {
+			write_str_(&buf[last], i - last);
+			write_str_("\r", 1);
+			last = i;
+		}
+	}
+	write_str_(&buf[last], cnt - last);
+	return cnt;
+}
+
+/* Interrupt handler needed for SDK UART implementation */
+void UART0_IRQHandler(void)
+{
+	UART_Handler(ConsoleUart);
+}
+
+static void uart_callback(uart_req_t *req, int error)
+{
+	BaseType_t xHigherPriorityTaskWoken = pdFALSE;
+	xTaskNotifyFromISR(
+		serial_task_id,
+		SERIAL_READ_NOTIFY,
+		eSetBits,
+		&xHigherPriorityTaskWoken
+	);
+	portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
+}
+
+void serial_enqueue_char(char chr)
+{
+	if (chr == 0x3) {
+		/* Control-C */
+		interrupt_trigger(EPIC_INT_CTRL_C);
+	}
+
+	if (xQueueSend(read_queue, &chr, 100) == errQUEUE_FULL) {
+		/* Queue overran, wait a bit */
+		vTaskDelay(portTICK_PERIOD_MS * 50);
+	}
+
+	interrupt_trigger(EPIC_INT_UART_RX);
+}
+
+void vSerialTask(void *pvParameters)
+{
+	serial_task_id = xTaskGetCurrentTaskHandle();
+
+	/* Setup UART interrupt */
+	NVIC_ClearPendingIRQ(UART0_IRQn);
+	NVIC_DisableIRQ(UART0_IRQn);
+	NVIC_SetPriority(UART0_IRQn, 6);
+	NVIC_EnableIRQ(UART0_IRQn);
+
+	unsigned char data;
+	uart_req_t read_req = {
+		.data     = &data,
+		.len      = 1,
+		.callback = uart_callback,
+	};
+
+	while (1) {
+		int ret = UART_ReadAsync(ConsoleUart, &read_req);
+		if (ret != E_NO_ERROR && ret != E_BUSY) {
+			LOG_ERR("serial", "error reading uart: %d", ret);
+			vTaskDelay(portMAX_DELAY);
+		}
+
+		ret = ulTaskNotifyTake(pdTRUE, portMAX_DELAY);
+
+		if (ret & SERIAL_WRITE_NOTIFY) {
+			serial_flush_from_thread();
+		}
+
+		if (ret & SERIAL_READ_NOTIFY) {
+			if (read_req.num > 0) {
+				serial_enqueue_char(*read_req.data);
+			}
+
+			while (UART_NumReadAvail(ConsoleUart) > 0) {
+				serial_enqueue_char(UART_ReadByte(ConsoleUart));
+			}
+
+			while (cdcacm_num_read_avail() > 0) {
+				serial_enqueue_char(cdcacm_read());
+			}
+		}
+	}
+}

epicardium/drivers/sleep.c

+#include "epicardium.h"
+#include "modules/modules.h"
+#include "os/core.h"
+
+#include "card10.h"
+#include "simo.h"
+#include "lp.h"
+#include "max86150.h"
+#include "MAX77650-Arduino-Library.h"
+
+#include "bb_drv.h"
+
+#include "max32665.h"
+#include "mxc_sys.h"
+#include "mxc_pins.h"
+
+#include <stdint.h>
+#include <limits.h>
+
+/* Most code is taken and adapted rom EvKitExamples/LP/main.c */
+
+static uint32_t old_clkcn;
+static uint32_t old_perckcn0, old_perckcn1;
+
+void GPIOWAKE_IRQHandler(void)
+{
+	/* Nothing to do here */
+}
+
+static void switchToHIRC(void)
+{
+	MXC_GCR->clkcn &= ~(MXC_S_GCR_CLKCN_PSC_DIV128);
+	MXC_GCR->clkcn |= MXC_S_GCR_CLKCN_PSC_DIV4;
+	MXC_GCR->clkcn |= MXC_F_GCR_CLKCN_HIRC_EN;
+
+	MXC_SETFIELD(
+		MXC_GCR->clkcn,
+		MXC_F_GCR_CLKCN_CLKSEL,
+		MXC_S_GCR_CLKCN_CLKSEL_HIRC
+	);
+
+	while (!(MXC_GCR->clkcn & MXC_F_GCR_CLKCN_CKRDY))
+		; /* Wait for the clock switch to occur */
+
+	/* Disable the now unused 96 MHz clock */
+	MXC_GCR->clkcn &= ~(MXC_F_GCR_CLKCN_HIRC96M_EN);
+
+	SystemCoreClockUpdate();
+}
+
+static void deepsleep(void)
+{
+	SIMO_setVregO_B(810); /* Reduce VCOREB to 0.81 V */
+	LP_FastWakeupEnable();
+	LP_EnterDeepSleepMode();
+	SIMO_setVregO_B(1000); /* Restore VCOREB to 1 V */
+}
+
+static void turnOffClocks(void)
+{
+	old_perckcn0 = MXC_GCR->perckcn0;
+	old_perckcn1 = MXC_GCR->perckcn1;
+
+	/* Allow the USB Switch to be turned off in deepsleep and backup modes. */
+	/* TODO: should this be the default setting? */
+	LP_USBSWLPDisable();
+
+	/* Disable all peripheral clocks except GPIO0 (needed for interrupt wakeup) */
+	MXC_GCR->perckcn0 = 0xFFFFFFFE;
+	MXC_GCR->perckcn1 = 0xFFFFFFFF;
+}
+
+static void turnOnClocks(void)
+{
+	MXC_GCR->perckcn0 = old_perckcn0;
+	MXC_GCR->perckcn1 = old_perckcn1;
+}
+
+/*
+ * Move most GPIOs into a special low power state with the fact
+ * in mind that the external 3.3 V are switched off.
+ *
+ * E.g. this means that the SD card pins need to be pulled low
+ * to preven them from backfeeding into the 3.3 V rail via their
+ * external pull-up resistors.
+ *
+ * Pins needed to talk to the PMIC are left untouched.
+ * ECG AOUT and 32 kHz out as well.
+ */
+static void gpio_low_power(void)
+{
+	/* clang-format off */
+	const gpio_cfg_t pins_low_power[] = {
+		{ PORT_0, PIN_0, GPIO_FUNC_IN, GPIO_PAD_PULL_UP },      // FLash
+		{ PORT_0, PIN_1, GPIO_FUNC_IN, GPIO_PAD_PULL_UP },      // Flash
+		{ PORT_0, PIN_2, GPIO_FUNC_IN, GPIO_PAD_PULL_UP },      // Flash
+		{ PORT_0, PIN_3, GPIO_FUNC_IN, GPIO_PAD_PULL_UP },      // Flash
+		{ PORT_0, PIN_4, GPIO_FUNC_IN, GPIO_PAD_PULL_UP },      // Flash
+		{ PORT_0, PIN_5, GPIO_FUNC_IN, GPIO_PAD_PULL_UP },      // Flash
+		{ PORT_0, PIN_6, GPIO_FUNC_OUT, GPIO_PAD_NONE },        // I2C 3.3V
+		{ PORT_0, PIN_7, GPIO_FUNC_OUT, GPIO_PAD_NONE },        // I2C 3.3V
+		{ PORT_0, PIN_8, GPIO_FUNC_OUT, GPIO_PAD_NONE },        // Motor
+		{ PORT_0, PIN_9, GPIO_FUNC_IN, GPIO_PAD_PULL_UP },      // UART TX
+		{ PORT_0, PIN_10, GPIO_FUNC_IN, GPIO_PAD_PULL_UP },     // UART RX
+		{ PORT_0, PIN_11, GPIO_FUNC_IN, GPIO_PAD_PULL_DOWN },   // BMA400 interrupt
+		// 0, 12: PMIC IRQ
+		{ PORT_0, PIN_13, GPIO_FUNC_IN, GPIO_PAD_NONE },        // BHI160 interrupt, not sure if PP
+		// 0, 14: PMIC I2C
+		// 0, 15: PMIC I2C
+		{ PORT_0, PIN_16, GPIO_FUNC_IN, GPIO_PAD_PULL_UP },     // PMIC AMUX
+		{ PORT_0, PIN_17, GPIO_FUNC_IN, GPIO_PAD_PULL_DOWN },   // SOA GPIO
+		// 0, 18: ECG AOUT
+		// 0, 19: 32 kHz
+		{ PORT_0, PIN_20, GPIO_FUNC_IN, GPIO_PAD_PULL_DOWN },   // Wristband 1
+		{ PORT_0, PIN_21, GPIO_FUNC_IN, GPIO_PAD_PULL_DOWN },   // Wristband 2
+		{ PORT_0, PIN_22, GPIO_FUNC_IN, GPIO_PAD_PULL_DOWN },   // Wristband 3
+		{ PORT_0, PIN_23, GPIO_FUNC_OUT, GPIO_PAD_NONE },       // IR-LED
+		{ PORT_0, PIN_24, GPIO_FUNC_OUT, GPIO_PAD_NONE },       // display SS
+		{ PORT_0, PIN_25, GPIO_FUNC_OUT, GPIO_PAD_NONE },       // display MOSI
+		{ PORT_0, PIN_26, GPIO_FUNC_IN, GPIO_PAD_PULL_DOWN },   // SOA GPIO
+		{ PORT_0, PIN_27, GPIO_FUNC_OUT, GPIO_PAD_NONE },       // display SCK
+		{ PORT_0, PIN_28, GPIO_FUNC_OUT, GPIO_PAD_NONE },       // Backlight
+		{ PORT_0, PIN_29, GPIO_FUNC_IN, GPIO_PAD_PULL_DOWN },   // Wristband 4
+		// 0, 30: PMIC power hold
+		{ PORT_0, PIN_31, GPIO_FUNC_OUT, GPIO_PAD_NONE },   // ECG switch
+
+		{ PORT_1, PIN_0, GPIO_FUNC_OUT, GPIO_PAD_NONE },    // SDHC
+		{ PORT_1, PIN_1, GPIO_FUNC_OUT, GPIO_PAD_NONE },    // SDHC
+		{ PORT_1, PIN_2, GPIO_FUNC_OUT, GPIO_PAD_NONE },    // SDHC
+		{ PORT_1, PIN_3, GPIO_FUNC_OUT, GPIO_PAD_NONE },    // SDHC
+		{ PORT_1, PIN_4, GPIO_FUNC_OUT, GPIO_PAD_NONE },    // SDHC
+		{ PORT_1, PIN_5, GPIO_FUNC_OUT, GPIO_PAD_NONE },    // SDHC
+		{ PORT_1, PIN_6, GPIO_FUNC_OUT, GPIO_PAD_NONE },    // display RS
+		{ PORT_1, PIN_7, GPIO_FUNC_IN, GPIO_PAD_PULL_UP },  // Portexpander interrupt
+		{ PORT_1, PIN_8, GPIO_FUNC_IN, GPIO_PAD_PULL_UP },  // ECG CS TODO: better OUT high
+		{ PORT_1, PIN_9, GPIO_FUNC_OUT, GPIO_PAD_NONE },    // ECG SDI
+		{ PORT_1, PIN_10, GPIO_FUNC_IN, GPIO_PAD_PULL_UP }, // ECG SDO
+		{ PORT_1, PIN_11, GPIO_FUNC_IN, GPIO_PAD_PULL_UP }, // ECG SCK
+		{ PORT_1, PIN_11, GPIO_FUNC_IN, GPIO_PAD_PULL_UP }, // ECG INT
+		{ PORT_1, PIN_13, GPIO_FUNC_IN, GPIO_PAD_NONE },    // PPG Interrupt
+		{ PORT_1, PIN_14, GPIO_FUNC_OUT, GPIO_PAD_NONE },   // RGB LEDs
+		{ PORT_1, PIN_15, GPIO_FUNC_OUT, GPIO_PAD_NONE },   // RGB LEDs
+	};
+	/* clang-format on */
+
+	const unsigned int num_pins =
+		(sizeof(pins_low_power) / sizeof(gpio_cfg_t));
+	for (size_t i = 0; i < num_pins; i++) {
+		GPIO_OutClr(&pins_low_power[i]);
+		GPIO_Config(&pins_low_power[i]);
+	}
+}
+
+/*
+ * Go to deepsleep, turning off peripherals.
+ *
+ * This functions returns after waking up again.
+ * Currently the only wakeup source is an interrupt
+ * from the PMIC.
+ *
+ * Some peripherals and GPIOs are moved into a low
+ * power state before going to sleep. There is no guarantee
+ * that all peripherals will be moved to a low power state
+ *
+ * TODO: Move BHI160, BMA400, BME680, MAX30001 into a low
+ * power state.
+ *
+ * The state of the GPIOs and generally all peripherials
+ * on board is not restored after a wakeup.
+ */
+void sleep_deepsleep(void)
+{
+	LOG_WARN("pmic", "Powersave");
+	epic_disp_backlight(0);
+	epic_leds_set_rocket(0, 0);
+	epic_leds_set_rocket(1, 0);
+	epic_leds_set_rocket(2, 0);
+#if 1
+	/* This will fail if there is no
+     * harmonic board attached */
+	max86150_begin();
+	max86150_get_int1();
+	max86150_get_int2();
+	max86150_shut_down();
+#endif
+	epic_bhi160_disable_all_sensors();
+	epic_bme680_deinit();
+	epic_max30001_disable_sensor();
+	MAX77650_setEN_SBB2(0b100);
+	MAX77650_setSBIA_LPM(true);
+	core1_stop();
+	MAX77650_getINT_GLBL();
+	gpio_low_power();
+	if (ble_is_enabled()) {
+		BbDrvDisable();
+	}
+	turnOffClocks();
+
+	SYS_ClockSourceEnable(SYS_CLOCK_HIRC);
+	old_clkcn = MXC_GCR->clkcn;
+	switchToHIRC();
+	deepsleep();
+
+	/* Now wait for an interrupt to wake us up */
+
+	turnOnClocks();
+	MXC_GCR->clkcn = old_clkcn;
+	while (!(MXC_GCR->clkcn & MXC_F_GCR_CLKCN_CKRDY))
+		; /* Wait for the clock switch to occur */
+	SystemCoreClockUpdate();
+	MAX77650_setEN_SBB2(0b110);
+}
+
+int epic_sleep(uint32_t ms)
+{
+	/* Allow the interrupt module to break us out of a call to
+	 * epic_sleep() */
+	uint32_t count = ulTaskNotifyTake(pdTRUE, pdMS_TO_TICKS(ms));
+
+	if (count == 0) {
+		return 0;
+	} else {
+		return INT_MAX;
+	}
+}

epicardium/drivers/usb.c

+/**
+ *
+ * Implementation of public epic_usb_ interface
+ *
+ * Configuration and FLASH-specific implementation of USB mass storage device
+ * Configuration of USB CDCACM device
+ *
+ * USB descriptors for both are defined here.
+ *
+ */
+
+#include "epicardium.h"
+
+#include "fs/filesystem.h"
+#include "os/config.h"
+
+#include "usb/cdcacm.h"
+#include "usb/mass_storage.h"
+#include "usb/descriptors.h"
+#include "usb/epc_usb.h"
+
+#include "os/core.h"
+
+#include "mx25lba.h"
+#include "msc.h"
+
+#include "mxc_sys.h"
+#include "wdt.h"
+
+/* memory access callbacks for the mass storage (FLASH) device */
+static int mscmem_init();
+static uint32_t mscmem_size(void);
+static int mscmem_read(uint32_t lba, uint8_t *buffer);
+static int mscmem_write(uint32_t lba, uint8_t *buffer);
+static int mscmem_start();
+static int mscmem_stop();
+static int mscmem_ready();
+
+/* USB descriptors, definition at the end of this file */
+static usb_device_descriptor_t device_descriptor_cdcacm
+	__attribute__((aligned(4)));
+static struct config_descriptor_cdcacm config_descriptor_cdcacm
+	__attribute__((aligned(4)));
+static usb_device_descriptor_t device_descriptor_msc
+	__attribute__((aligned(4)));
+static struct config_descriptor_msc config_descriptor_msc
+	__attribute__((aligned(4)));
+
+/* definitions of config structs */
+static const msc_mem_t s_mscCallbacks = {
+	mscmem_init, mscmem_start, mscmem_stop,  mscmem_ready,
+	mscmem_size, mscmem_read,  mscmem_write,
+};
+
+static struct esb_device_descriptors s_dd_cdcacm = {
+	.device = &device_descriptor_cdcacm, .cdcacm = &config_descriptor_cdcacm
+};
+
+static struct esb_device_descriptors s_dd_msc = {
+	.device = &device_descriptor_msc, .msc = &config_descriptor_msc
+};
+
+static struct esb_config s_cfg_cdcacm = {
+	.name        = "cdcacm",
+	.init        = esb_cdc_init,
+	.configure   = esb_cdc_configure,
+	.deconfigure = esb_cdc_deconfigure,
+	.deinit      = NULL,
+
+	.descriptors = &s_dd_cdcacm,
+	.deviceData  = NULL,
+};
+
+static struct esb_config s_cfg_msc = {
+	.name        = "msc FLASH",
+	.init        = esb_msc_init,
+	.configure   = esb_msc_configure,
+	.deconfigure = esb_msc_deconfigure,
+	.deinit      = NULL,
+
+	.descriptors = &s_dd_msc,
+	.deviceData  = (void *)&s_mscCallbacks,
+};
+
+/* function implementations */
+
+static int dirty = 0;
+static int mscmem_init()
+{
+	LOG_DEBUG("msc", "mem.init");
+	fatfs_detach();
+	return mx25_init();
+}
+
+static uint32_t mscmem_size(void)
+{
+	return mx25_size();
+}
+
+static int mscmem_read(uint32_t lba, uint8_t *buffer)
+{
+	/* Reset the watchdog as this interrupt might be
+	 * firing back to back for a few seconds. */
+	WDT_ResetTimer(MXC_WDT0);
+	return mx25_read(lba, buffer);
+}
+
+static int mscmem_write(uint32_t lba, uint8_t *buffer)
+{
+	if (dirty == 0) {
+		//bootloader_dirty();
+	}
+	dirty = 2;
+	/* Reset the watchdog as this interrupt might be
+	 * firing back to back for a few seconds. */
+	WDT_ResetTimer(MXC_WDT0);
+	return mx25_write(lba, buffer);
+}
+
+static int mscmem_start()
+{
+	return mx25_start();
+}
+
+static int mscmem_stop()
+{
+	LOG_DEBUG("msc", "mem.stop");
+	int ret = mx25_stop();
+	fatfs_schedule_attach();
+	return ret;
+}
+
+static int mscmem_ready()
+{
+	if (dirty) {
+		dirty--;
+		if (dirty == 0) {
+			LOG_DEBUG("msc", "sync");
+			mx25_sync();
+			//bootloader_clean();
+		}
+	}
+	return mx25_ready();
+}
+
+static bool s_fsDetached = false;
+int epic_usb_shutdown(void)
+{
+	esb_deinit();
+	if (s_fsDetached) {
+		fatfs_attach();
+		load_config();
+	}
+	return 0;
+}
+
+int epic_usb_storage(void)
+{
+	esb_deinit();
+	s_fsDetached = true;
+	return esb_init(&s_cfg_msc);
+}
+
+int epic_usb_cdcacm(void)
+{
+	esb_deinit();
+	if (s_fsDetached) {
+		fatfs_attach();
+		load_config();
+	}
+	return esb_init(&s_cfg_cdcacm);
+}
+
+/* clang-format off */
+static usb_device_descriptor_t device_descriptor_cdcacm = {
+	.bLength            = 0x12,
+	.bDescriptorType    = DT_DEVICE,
+	.bcdUSB             = 0x0110,
+	.bDeviceClass       = CLS_COMM,
+	.bDeviceSubClass    = 0x00,
+	.bDeviceProtocol    = 0x00,
+	.bMaxPacketSize     = 0x40,
+	.idVendor           = VNDR_MAXIM,
+	.idProduct          = 0x003C,
+	.bcdDevice          = 0x0100,
+	.iManufacturer      = 0x01,
+	.iProduct           = 0x02,
+	.iSerialNumber      = 0x00,
+	.bNumConfigurations = 0x01
+};
+
+static struct config_descriptor_cdcacm config_descriptor_cdcacm = {
+    .config = {
+        .bLength            = 0x09,
+        .bDescriptorType    = DT_CONFIG,
+        .wTotalLength       = 0x0043,     /*  sizeof(struct config_descriptor_cdcacm) */
+        .bNumInterfaces     = 0x02,
+        .bConfigurationValue= 0x01,
+        .iConfiguration     = 0x00,
+        .bmAttributes       = 0xE0,       /*  (self-powered, remote wakeup) */
+        .bMaxPower          = 0x01,       /*  MaxPower is 2ma (units are 2ma/bit) */
+    },
+    .comm_interface = { /*  First Interface Descriptor For Comm Class Interface */
+        .bLength            = 0x09,
+        .bDescriptorType    = DT_INTERFACE,
+        .bInterfaceNumber   = 0x00,
+        .bAlternateSetting  = 0x00,
+        .bNumEndpoints      = 0x01,
+        .bInterfaceClass    = CLS_COMM,
+        .bInterfaceSubClass = SCLS_ACM,
+        .bInterfaceProtocol = 0x00,
+        .iInterface         = 0x00,
+    },
+    .header_functional = {
+        0x05,         /*  bFunctionalLength = 5           */
+        DT_FUNCTIONAL,/*  bDescriptorType                 */
+        0x00,         /*  bDescriptorSubtype              */
+        0x10, 0x01,   /*  bcdCDC                          */
+    },
+    .call_management = {
+        0x05,         /*  bFunctionalLength = 5           */
+        DT_FUNCTIONAL,/*  bDescriptorType                 */
+        0x01,         /*  bDescriptorSubtype              */
+        0x03,         /*  bmCapabilities = Device handles call management itself (0x01), management over data class (0x02) */
+        0x01,         /*  bmDataInterface                 */
+    },
+    .acm_functional = {
+        0x04,         /*  bFunctionalLength = 4           */
+        DT_FUNCTIONAL,/*  bDescriptorType                 */
+        0x02,         /*  bDescriptorSubtype              */
+        0x02,         /*  bmCapabilities                  */
+    },
+    .union_functional = {
+        0x05,         /*  bFunctionalLength = 5           */
+        DT_FUNCTIONAL,/*  bDescriptorType                 */
+        0x06,         /*  bDescriptorSubtype              */
+        0x00,         /*  bmMasterInterface               */
+        0x01,         /*  bmSlaveInterface0               */
+    },
+    .endpoint_notify = {
+        .bLength            = 0x07,
+        .bDescriptorType    = DT_ENDPOINT,
+        .bEndpointAddress   = 0x80 | ESB_ENDPOINT_CDCACM_NOTIFY,
+        .bmAttributes       = ATTR_INTERRUPT,
+        .wMaxPacketSize     = 0x0040,
+        .bInterval          = 0xff,
+    },
+    .data_interface = {
+        .bLength            = 0x09,
+        .bDescriptorType    = DT_INTERFACE,
+        .bInterfaceNumber   = 0x01,
+        .bAlternateSetting  = 0x00,
+        .bNumEndpoints      = 0x02,
+        .bInterfaceClass    = CLS_DATA,
+        .bInterfaceSubClass = 0x00,
+        .bInterfaceProtocol = 0x00,
+        .iInterface         = 0x00, //not 1?
+    },
+    .endpoint_out = {
+        .bLength            = 0x07,
+        .bDescriptorType    = DT_ENDPOINT,
+        .bEndpointAddress   = ESB_ENDPOINT_CDCACM_OUT,
+        .bmAttributes       = ATTR_BULK,
+        .wMaxPacketSize     = 0x0040,
+        .bInterval          = 0x00,
+    },
+    .endpoint_in = {
+        .bLength            = 0x07,
+        .bDescriptorType    = DT_ENDPOINT,
+        .bEndpointAddress   = 0x80 | ESB_ENDPOINT_CDCACM_IN,
+        .bmAttributes       = ATTR_BULK,
+        .wMaxPacketSize     = 0x0040,
+        .bInterval          = 0x00
+    }
+};
+
+static usb_device_descriptor_t device_descriptor_msc = {
+	.bLength            = 0x12,
+	.bDescriptorType    = DT_DEVICE,
+	.bcdUSB             = 0x0200,
+	.bDeviceClass       = CLS_UNSPECIFIED,
+	.bDeviceSubClass    = 0x00,
+	.bDeviceProtocol    = 0x00,
+	.bMaxPacketSize     = 0x40,
+	.idVendor           = VNDR_MAXIM,
+	.idProduct          = 0x4402,
+	.bcdDevice          = 0x0100,
+	.iManufacturer      = 0x01,
+	.iProduct           = 0x02,
+	.iSerialNumber      = 0x03,
+	.bNumConfigurations = 0x01
+};
+
+static struct config_descriptor_msc config_descriptor_msc =
+{
+    .config = {
+        .bLength            = 0x09,
+        .bDescriptorType    = DT_CONFIG,
+        .wTotalLength       = 0x0020,
+        .bNumInterfaces     = 0x01,
+        .bConfigurationValue= 0x01,
+        .iConfiguration     = 0x00,
+        .bmAttributes       = 0xC0,       /* (self-powered, no remote wakeup) */
+        .bMaxPower          = 0x32,
+    },
+    .msc_interface = {
+        .bLength                = 0x09,
+        .bDescriptorType        = DT_INTERFACE,
+        .bInterfaceNumber       = 0x00,
+        .bAlternateSetting      = 0x00,
+        .bNumEndpoints          = 0x02,
+        .bInterfaceClass        = CLS_MASS_STOR,
+        .bInterfaceSubClass     = SCLS_SCSI_CMDS,
+        .bInterfaceProtocol     = PROT_BULK_TRANS,
+        .iInterface             = 0x00,
+    },
+    .endpoint_out = {
+        .bLength            = 0x07,
+        .bDescriptorType    = DT_ENDPOINT,
+        .bEndpointAddress   = ESB_ENDPOINT_MSC_OUT,
+        .bmAttributes       = ATTR_BULK,
+        .wMaxPacketSize     = 0x0040,
+        .bInterval          = 0x00,
+    },
+    .endpoint_in = {
+        .bLength            = 0x07,
+        .bDescriptorType    = DT_ENDPOINT,
+        .bEndpointAddress   = 0x80 | ESB_ENDPOINT_MSC_IN,
+        .bmAttributes       = ATTR_BULK,
+        .wMaxPacketSize     = 0x0040,
+        .bInterval          = 0x00
+    }
+};
+/* clang-format on */

epicardium/drivers/vibra.c

+#include "gpio.h"
+#include "FreeRTOS.h"
+#include "timers.h"
+
+static const gpio_cfg_t motor_pin = {
+	PORT_0, PIN_8, GPIO_FUNC_OUT, GPIO_PAD_NONE
+};
+
+static StaticTimer_t vibra_timer_data;
+static TimerHandle_t vibra_timer = NULL;
+
+void epic_vibra_set(int status)
+{
+	if (status) {
+		GPIO_OutSet(&motor_pin);
+	} else {
+		GPIO_OutClr(&motor_pin);
+	}
+}
+
+void vTimerCallback()
+{
+	epic_vibra_set(0);
+}
+
+void epic_vibra_vibrate(int millis)
+{
+	int ticks = millis * (configTICK_RATE_HZ / 1000);
+
+	if (vibra_timer == NULL) {
+		vibra_timer = xTimerCreateStatic(
+			"vibratimer",
+			1,
+			pdFALSE, /* one-shot */
+			0,
+			vTimerCallback,
+			&vibra_timer_data);
+	}
+
+	/* Make sure the duration is valid */
+	if (ticks < 1) {
+		/* Disable a potentially running motor / timer */
+		epic_vibra_set(0);
+		xTimerStop(vibra_timer, 0);
+		return;
+	}
+
+	if (vibra_timer != NULL) {
+		epic_vibra_set(1);
+		xTimerChangePeriod(vibra_timer, ticks, 0);
+	}
+}

epicardium/modules/watchdog.c → epicardium/drivers/watchdog.c

-#include "modules/log.h"
+#include "os/core.h"
 #include "modules/modules.h"
 
 #include "timers.h"