From 2e00c2b35710d858814fb4162755e5bfea267fa1 Mon Sep 17 00:00:00 2001
From: Rahix <rahix@rahix.de>
Date: Sun, 21 Jul 2019 14:49:42 +0200
Subject: [PATCH] feat(epicardium): Add a lock for i2c
Multiple tasks might access the i2c bus simultaneously. To prevent
race conditions, this patch introduces a lock which tasks should
acquire before accessing the bus.
Signed-off-by: Rahix <rahix@rahix.de>
---
epicardium/main.c | 1 +
epicardium/modules/bhi.c | 21 ++++++++++++++-------
epicardium/modules/i2c.c | 33 +++++++++++++++++++++++++++++++++
epicardium/modules/meson.build | 1 +
epicardium/modules/modules.h | 5 +++++
epicardium/modules/pmic.c | 17 +++++++++++++----
6 files changed, 67 insertions(+), 11 deletions(-)
create mode 100644 epicardium/modules/i2c.c
diff --git a/epicardium/main.c b/epicardium/main.c
index e6ac3ea9..b7ab3419 100644
--- a/epicardium/main.c
+++ b/epicardium/main.c
@@ -60,6 +60,7 @@ int main(void)
fatfs_init();
api_interrupt_init();
stream_init();
+ i2c_init();
LOG_INFO("startup", "Initializing tasks ...");
diff --git a/epicardium/modules/bhi.c b/epicardium/modules/bhi.c
index 5e05e672..79ce0a72 100644
--- a/epicardium/modules/bhi.c
+++ b/epicardium/modules/bhi.c
@@ -115,7 +115,8 @@ int epic_bhi160_enable_sensor(
return -ENODEV;
}
- if (xSemaphoreTake(bhi160_mutex, LOCK_WAIT) == pdTRUE) {
+ if (i2c_lock() == 0 &&
+ xSemaphoreTake(bhi160_mutex, LOCK_WAIT) == pdTRUE) {
struct stream_info *stream = &bhi160_streams[sensor_type];
stream->item_size = bhi160_lookup_data_size(sensor_type);
/* TODO: Sanity check length */
@@ -138,6 +139,7 @@ int epic_bhi160_enable_sensor(
0,
config->dynamic_range /* dynamic range is sensor dependent */
);
+ i2c_unlock();
xSemaphoreGive(bhi160_mutex);
} else {
return -EBUSY;
@@ -153,13 +155,15 @@ int epic_bhi160_disable_sensor(enum bhi160_sensor_type sensor_type)
return -ENODEV;
}
- if (xSemaphoreTake(bhi160_mutex, LOCK_WAIT) == pdTRUE) {
+ if (i2c_lock() == 0 &&
+ xSemaphoreTake(bhi160_mutex, LOCK_WAIT) == pdTRUE) {
struct stream_info *stream = &bhi160_streams[sensor_type];
stream_deregister(bhi160_lookup_sd(sensor_type), stream);
vQueueDelete(stream->queue);
stream->queue = NULL;
bhy_disable_virtual_sensor(vs_id, VS_WAKEUP);
+ i2c_unlock();
xSemaphoreGive(bhi160_mutex);
} else {
return -EBUSY;
@@ -233,7 +237,8 @@ static int bhi160_fetch_fifo(void)
/* Number of bytes left in BHI160's FIFO buffer */
uint16_t bytes_left_in_fifo = 1;
- if (xSemaphoreTake(bhi160_mutex, LOCK_WAIT) != pdTRUE) {
+ if (i2c_lock() < 0 ||
+ xSemaphoreTake(bhi160_mutex, LOCK_WAIT) != pdTRUE) {
return -EBUSY;
}
@@ -282,6 +287,7 @@ static int bhi160_fetch_fifo(void)
}
xSemaphoreGive(bhi160_mutex);
+ i2c_unlock();
return 0;
}
@@ -310,8 +316,8 @@ void vBhi160Task(void *pvParameters)
bhi160_mutex = xSemaphoreCreateMutexStatic(&bhi160_mutex_data);
/* Take Mutex during initialization, just in case */
- if (xSemaphoreTake(bhi160_mutex, 0) != pdTRUE) {
- LOG_CRIT("bhi160", "Failed to acquire BHI160 mutex!");
+ if (i2c_lock() < 0 || xSemaphoreTake(bhi160_mutex, 0) != pdTRUE) {
+ LOG_CRIT("bhi160", "Failed to acquire BHI160/i2c mutex!");
vTaskDelay(portMAX_DELAY);
}
@@ -336,8 +342,7 @@ void vBhi160Task(void *pvParameters)
vTaskDelay(portMAX_DELAY);
}
- /* Wait for first two interrupts */
- ulTaskNotifyTake(pdTRUE, pdMS_TO_TICKS(100));
+ /* Wait for first interrupt */
ulTaskNotifyTake(pdTRUE, pdMS_TO_TICKS(100));
/* Remap axes to match card10 layout */
@@ -356,6 +361,8 @@ void vBhi160Task(void *pvParameters)
xSemaphoreGive(bhi160_mutex);
+ i2c_unlock();
+
/* ----------------------------------------- */
while (1) {
diff --git a/epicardium/modules/i2c.c b/epicardium/modules/i2c.c
new file mode 100644
index 00000000..f7ba63e3
--- /dev/null
+++ b/epicardium/modules/i2c.c
@@ -0,0 +1,33 @@
+#include "modules/log.h"
+#include "modules/modules.h"
+
+#include "FreeRTOS.h"
+#include "task.h"
+#include "semphr.h"
+
+#include <errno.h>
+
+static StaticSemaphore_t i2c_mutex_data;
+static SemaphoreHandle_t i2c_mutex;
+
+int i2c_init(void)
+{
+ i2c_mutex = xSemaphoreCreateMutexStatic(&i2c_mutex_data);
+ return 0;
+}
+
+int i2c_lock(void)
+{
+ if (xSemaphoreTake(i2c_mutex, pdMS_TO_TICKS(100)) != pdTRUE) {
+ LOG_WARN("i2c", "Mutex is busy");
+ return -EBUSY;
+ }
+ return 0;
+}
+
+void i2c_unlock(void)
+{
+ if (xSemaphoreGive(i2c_mutex) != pdTRUE) {
+ LOG_ERR("i2c", "Mutex was not acquired correctly");
+ }
+}
diff --git a/epicardium/modules/meson.build b/epicardium/modules/meson.build
index e59aeaee..0732576c 100644
--- a/epicardium/modules/meson.build
+++ b/epicardium/modules/meson.build
@@ -3,6 +3,7 @@ module_sources = files(
'display.c',
'fatfs.c',
'fatfs_fileops.c',
+ 'i2c.c',
'leds.c',
'log.c',
'pmic.c',
diff --git a/epicardium/modules/modules.h b/epicardium/modules/modules.h
index f09caa39..d1e92dcd 100644
--- a/epicardium/modules/modules.h
+++ b/epicardium/modules/modules.h
@@ -26,6 +26,11 @@ void vPmicTask(void *pvParameters);
#define BHI160_MUTEX_WAIT_MS 50
void vBhi160Task(void *pvParameters);
+/* ---------- I2C ---------------------------------------------------------- */
+int i2c_init(void);
+int i2c_lock(void);
+void i2c_unlock(void);
+
// Forces an unlock of the display. Only to be used in epicardium
void disp_forcelock();
#endif /* MODULES_H */
diff --git a/epicardium/modules/pmic.c b/epicardium/modules/pmic.c
index a41b38aa..64f6526f 100644
--- a/epicardium/modules/pmic.c
+++ b/epicardium/modules/pmic.c
@@ -27,9 +27,9 @@ void pmic_interrupt_callback(void *_)
void vPmicTask(void *pvParameters)
{
- int count = 0;
+ int count = 0;
portTickType delay = portMAX_DELAY;
- pmic_task_id = xTaskGetCurrentTaskHandle();
+ pmic_task_id = xTaskGetCurrentTaskHandle();
while (1) {
ulTaskNotifyTake(pdTRUE, delay);
@@ -43,7 +43,13 @@ void vPmicTask(void *pvParameters)
MAX77650_setSFT_RST(0x2);
}
+ while (i2c_lock() < 0) {
+ LOG_WARN("pmic", "Failed to acquire i2c. Retrying.");
+ vTaskDelay(pdMS_TO_TICKS(500));
+ }
+
uint8_t int_flag = MAX77650_getINT_GLBL();
+ i2c_unlock();
if (int_flag & MAX77650_INT_nEN_F) {
/* Button was pressed */
@@ -62,8 +68,11 @@ void vPmicTask(void *pvParameters)
/* 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);
+ LOG_WARN(
+ "pmic",
+ "Unhandled PMIC Interrupt: %x",
+ int_flag
+ );
}
if (delay != portMAX_DELAY) {
--
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