From e60c164cdb50a0aa268165e57de0a4cd0d58fcdf Mon Sep 17 00:00:00 2001
From: David Brownell <dbrownell@users.sourceforge.net>
Date: Sat, 2 Jan 2010 15:53:03 -0800
Subject: [PATCH] ARM: ADIv5 symbol and comment cleanup
Instead of magic numbers, use their AP_REG_* constants. Rename
the ROM address symbol as BASE to match ARM's documentation.
Comment various other symbols in the header; add some missing ones.
Remove an unused struct. Add some doxygen for stuff including the
DAP structure and initialization.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
---
src/target/arm_adi_v5.c | 75 +++++++++++++++++++++++++++++++----------
src/target/arm_adi_v5.h | 48 ++++++++++++++++++++------
2 files changed, 94 insertions(+), 29 deletions(-)
diff --git a/src/target/arm_adi_v5.c b/src/target/arm_adi_v5.c
index 6ca50ab7c..59f5638ec 100644
--- a/src/target/arm_adi_v5.c
+++ b/src/target/arm_adi_v5.c
@@ -7,7 +7,7 @@
* *
* Copyright (C) 2009 by Oyvind Harboe *
* oyvind.harboe@zylin.com *
- * *
+ * *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
@@ -23,16 +23,34 @@
* Free Software Foundation, Inc., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
***************************************************************************/
-/***************************************************************************
- * *
- * This file implements support for the ARM Debug Interface v5 (ADI_V5) *
- * *
- * ARM(tm) Debug Interface v5 Architecture Specification ARM IHI 0031A *
- * *
- * CoreSight(tm) DAP-Lite TRM, ARM DDI 0316D *
- * Cortex-M3(tm) TRM, ARM DDI 0337G *
- * *
-***************************************************************************/
+
+/**
+ * @file
+ * This file implements support for the ARM Debug Interface version 5 (ADIv5)
+ * debugging architecture. Compared with previous versions, this includes
+ * a low pin-count Serial Wire Debug (SWD) alternative to JTAG for message
+ * transport, and focusses on memory mapped resources as defined by the
+ * CoreSight architecture.
+ *
+ * A key concept in ADIv5 is the Debug Access Port, or DAP. A DAP has two
+ * basic components: a Debug Port (DP) transporting messages to and from a
+ * debugger, and an Access Port (AP) accessing resources. Three types of DP
+ * are defined. One uses only JTAG for communication, and is called JTAG-DP.
+ * One uses only SWD for communication, and is called SW-DP. The third can
+ * use either SWD or JTAG, and is called SWJ-DP. The most common type of AP
+ * is used to access memory mapped resources and is called a MEM-AP. Also a
+ * JTAG-AP is also defined, bridging to JTAG resources; those are uncommon.
+ */
+
+/*
+ * Relevant specifications from ARM include:
+ *
+ * ARM(tm) Debug Interface v5 Architecture Specification ARM IHI 0031A
+ * CoreSight(tm) v1.0 Architecture Specification ARM IHI 0029B
+ *
+ * CoreSight(tm) DAP-Lite TRM, ARM DDI 0316D
+ * Cortex-M3(tm) TRM, ARM DDI 0337G
+ */
#ifdef HAVE_CONFIG_H
#include "config.h"
@@ -950,6 +968,13 @@ int mem_ap_read_buf_u8(struct swjdp_common *swjdp, uint8_t *buffer, int count, u
return retval;
}
+/**
+ * Initialize a DAP.
+ *
+ * @todo Rename this. We also need an initialization scheme which account
+ * for SWD transports not just JTAG; that will need to address differences
+ * in layering. (JTAG is useful without any debug target; but not SWD.)
+ */
int ahbap_debugport_init(struct swjdp_common *swjdp)
{
uint32_t idreg, romaddr, dummy;
@@ -959,9 +984,17 @@ int ahbap_debugport_init(struct swjdp_common *swjdp)
LOG_DEBUG(" ");
+ /* Default MEM-AP setup.
+ *
+ * REVISIT AP #0 may be an inappropriate default for this.
+ * Should we probe, or receve a hint from the caller?
+ * Presumably we can ignore the possibility of multiple APs.
+ */
swjdp->apsel = 0;
swjdp->ap_csw_value = -1;
swjdp->ap_tar_value = -1;
+
+ /* DP initialization */
swjdp->trans_mode = TRANS_MODE_ATOMIC;
dap_dp_read_reg(swjdp, &dummy, DP_CTRL_STAT);
dap_dp_write_reg(swjdp, SSTICKYERR, DP_CTRL_STAT);
@@ -999,8 +1032,14 @@ int ahbap_debugport_init(struct swjdp_common *swjdp)
dap_dp_write_reg(swjdp, swjdp->dp_ctrl_stat, DP_CTRL_STAT);
dap_dp_read_reg(swjdp, &dummy, DP_CTRL_STAT);
- dap_ap_read_reg_u32(swjdp, 0xFC, &idreg);
- dap_ap_read_reg_u32(swjdp, 0xF8, &romaddr);
+ /*
+ * REVISIT this isn't actually *initializing* anything in an AP,
+ * and doesn't care if it's a MEM-AP at all (much less AHB-AP).
+ * Should it? If the ROM address is valid, is this the right
+ * place to scan the table and do any topology detection?
+ */
+ dap_ap_read_reg_u32(swjdp, AP_REG_IDR, &idreg);
+ dap_ap_read_reg_u32(swjdp, AP_REG_BASE, &romaddr);
LOG_DEBUG("AHB-AP ID Register 0x%" PRIx32 ", Debug ROM Address 0x%" PRIx32 "", idreg, romaddr);
@@ -1035,8 +1074,8 @@ int dap_info_command(struct command_context *cmd_ctx, struct swjdp_common *swjdp
apselold = swjdp->apsel;
dap_ap_select(swjdp, apsel);
- dap_ap_read_reg_u32(swjdp, 0xF8, &dbgbase);
- dap_ap_read_reg_u32(swjdp, 0xFC, &apid);
+ dap_ap_read_reg_u32(swjdp, AP_REG_BASE, &dbgbase);
+ dap_ap_read_reg_u32(swjdp, AP_REG_IDR, &apid);
swjdp_transaction_endcheck(swjdp);
/* Now we read ROM table ID registers, ref. ARM IHI 0029B sec */
mem_ap = ((apid&0x10000) && ((apid&0x0F) != 0));
@@ -1387,7 +1426,7 @@ DAP_COMMAND_HANDLER(dap_baseaddr_command)
if (apselsave != apsel)
dap_ap_select(swjdp, apsel);
- dap_ap_read_reg_u32(swjdp, 0xF8, &baseaddr);
+ dap_ap_read_reg_u32(swjdp, AP_REG_BASE, &baseaddr);
retval = swjdp_transaction_endcheck(swjdp);
command_print(CMD_CTX, "0x%8.8" PRIx32, baseaddr);
@@ -1436,7 +1475,7 @@ DAP_COMMAND_HANDLER(dap_apsel_command)
}
dap_ap_select(swjdp, apsel);
- dap_ap_read_reg_u32(swjdp, 0xFC, &apid);
+ dap_ap_read_reg_u32(swjdp, AP_REG_IDR, &apid);
retval = swjdp_transaction_endcheck(swjdp);
command_print(CMD_CTX, "ap %" PRIi32 " selected, identification register 0x%8.8" PRIx32,
apsel, apid);
@@ -1464,7 +1503,7 @@ DAP_COMMAND_HANDLER(dap_apid_command)
if (apselsave != apsel)
dap_ap_select(swjdp, apsel);
- dap_ap_read_reg_u32(swjdp, 0xFC, &apid);
+ dap_ap_read_reg_u32(swjdp, AP_REG_IDR, &apid);
retval = swjdp_transaction_endcheck(swjdp);
command_print(CMD_CTX, "0x%8.8" PRIx32, apid);
if (apselsave != apsel)
diff --git a/src/target/arm_adi_v5.h b/src/target/arm_adi_v5.h
index a78193c6d..2a0968440 100644
--- a/src/target/arm_adi_v5.h
+++ b/src/target/arm_adi_v5.h
@@ -23,6 +23,13 @@
#ifndef ARM_ADI_V5_H
#define ARM_ADI_V5_H
+/**
+ * @file
+ * This defines formats and data structures used to talk to ADIv5 entities.
+ * Those include a DAP, different types of Debug Port (DP), and memory mapped
+ * resources accessed through a MEM-AP.
+ */
+
#include "arm_jtag.h"
#define DAP_IR_DPACC 0xA
@@ -30,14 +37,22 @@
#define DPAP_WRITE 0
#define DPAP_READ 1
+
+/* A[3:0] for DP registers (for JTAG, stored in DPACC) */
#define DP_ZERO 0
#define DP_CTRL_STAT 0x4
#define DP_SELECT 0x8
#define DP_RDBUFF 0xC
+/* Fields of the DP's CTRL/STAT register */
#define CORUNDETECT (1 << 0)
#define SSTICKYORUN (1 << 1)
+/* 3:2 - transaction mode (e.g. pushed compare) */
#define SSTICKYERR (1 << 5)
+#define READOK (1 << 6)
+#define WDATAERR (1 << 7)
+/* 11:8 - mask lanes for pushed compare or verify ops */
+/* 21:12 - transaction counter */
#define CDBGRSTREQ (1 << 26)
#define CDBGRSTACK (1 << 27)
#define CDBGPWRUPREQ (1 << 28)
@@ -45,26 +60,35 @@
#define CSYSPWRUPREQ (1 << 30)
#define CSYSPWRUPACK (1 << 31)
-#define AP_REG_CSW 0x00
+/* MEM-AP register addresses */
+/* TODO: rename as MEM_AP_REG_* */
+#define AP_REG_CSW 0x00
#define AP_REG_TAR 0x04
#define AP_REG_DRW 0x0C
#define AP_REG_BD0 0x10
#define AP_REG_BD1 0x14
#define AP_REG_BD2 0x18
#define AP_REG_BD3 0x1C
-#define AP_REG_DBGROMA 0xF8
+#define AP_REG_CFG 0xF4 /* big endian? */
+#define AP_REG_BASE 0xF8
+
+/* Generic AP register address */
#define AP_REG_IDR 0xFC
+/* Fields of the MEM-AP's CSW register */
#define CSW_8BIT 0
#define CSW_16BIT 1
#define CSW_32BIT 2
-
#define CSW_ADDRINC_MASK (3 << 4)
#define CSW_ADDRINC_OFF 0
#define CSW_ADDRINC_SINGLE (1 << 4)
#define CSW_ADDRINC_PACKED (2 << 4)
-#define CSW_HPROT (1 << 25)
-#define CSW_MASTER_DEBUG (1 << 29)
+#define CSW_DEVICE_EN (1 << 6)
+#define CSW_TRIN_PROG (1 << 7)
+#define CSW_SPIDEN (1 << 23)
+/* 30:24 - implementation-defined! */
+#define CSW_HPROT (1 << 25) /* ? */
+#define CSW_MASTER_DEBUG (1 << 29) /* ? */
#define CSW_DBGSWENABLE (1 << 31)
/* transaction mode */
@@ -74,12 +98,14 @@
/* Freerunning transactions with delays and overrun checking */
#define TRANS_MODE_COMPOSITE 2
-struct swjdp_reg
-{
- int addr;
- struct arm_jtag *jtag_info;
-};
-
+/**
+ * This represents an ARM Debug Interface (v5) Debug Access Port (DAP).
+ * A DAP has two types of component: one Debug Port (DP), which is a
+ * transport agent; and at least one Access Port (AP), controlling
+ * resource access. Most common is a MEM-AP, for memory access.
+ *
+ * @todo Rename "swjdp_common" as "dap". Use of SWJ-DP is optional!
+ */
struct swjdp_common
{
struct arm_jtag *jtag_info;
--
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