OMAP: PM debug: Add PRCM register dump support

Allows dumping out current register contents from the debug filesystem, and
also allows user to add arbitrary register save points into code. Current
register contents are available under debugfs at:

[debugfs]/pm_debug/registers/current

To add a save point, do following:

From module init (or somewhere before the save call, called only once):
  pm_dbg_init_regset(n); // n=1..4, allocates memory for dump area #n

From arbitrary code location:
  pm_dbg_regset_save(n); // n=1..4, saves registers to dump area #n

After this, the register dump can be seen under [debugfs]/pm_debug/registers/n

Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-omap2/pm-debug.c

@@ -52,6 +52,8 @@ int omap2_pm_debug;
 	regs[reg_count].name = #reg; \
 	regs[reg_count++].val = __raw_readl(OMAP2_IO_ADDRESS(0x480fe000 + (off)))
 
+static int __init pm_dbg_init(void);
+
 void omap2_pm_dump(int mode, int resume, unsigned int us)
 {
 	struct reg {
@@ -157,6 +159,8 @@ void omap2_pm_dump(int mode, int resume, unsigned int us)
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 
+static void pm_dbg_regset_store(u32 *ptr);
+
 struct dentry *pm_dbg_dir;
 
 static int pm_dbg_init_done;
@@ -166,6 +170,160 @@ enum {
 	DEBUG_FILE_TIMERS,
 };
 
+struct pm_module_def {
+	char name[8]; /* Name of the module */
+	short type; /* CM or PRM */
+	unsigned short offset;
+	int low; /* First register address on this module */
+	int high; /* Last register address on this module */
+};
+
+#define MOD_CM 0
+#define MOD_PRM 1
+
+static const struct pm_module_def *pm_dbg_reg_modules;
+static const struct pm_module_def omap3_pm_reg_modules[] = {
+	{ "IVA2", MOD_CM, OMAP3430_IVA2_MOD, 0, 0x4c },
+	{ "OCP", MOD_CM, OCP_MOD, 0, 0x10 },
+	{ "MPU", MOD_CM, MPU_MOD, 4, 0x4c },
+	{ "CORE", MOD_CM, CORE_MOD, 0, 0x4c },
+	{ "SGX", MOD_CM, OMAP3430ES2_SGX_MOD, 0, 0x4c },
+	{ "WKUP", MOD_CM, WKUP_MOD, 0, 0x40 },
+	{ "CCR", MOD_CM, PLL_MOD, 0, 0x70 },
+	{ "DSS", MOD_CM, OMAP3430_DSS_MOD, 0, 0x4c },
+	{ "CAM", MOD_CM, OMAP3430_CAM_MOD, 0, 0x4c },
+	{ "PER", MOD_CM, OMAP3430_PER_MOD, 0, 0x4c },
+	{ "EMU", MOD_CM, OMAP3430_EMU_MOD, 0x40, 0x54 },
+	{ "NEON", MOD_CM, OMAP3430_NEON_MOD, 0x20, 0x48 },
+	{ "USB", MOD_CM, OMAP3430ES2_USBHOST_MOD, 0, 0x4c },
+
+	{ "IVA2", MOD_PRM, OMAP3430_IVA2_MOD, 0x50, 0xfc },
+	{ "OCP", MOD_PRM, OCP_MOD, 4, 0x1c },
+	{ "MPU", MOD_PRM, MPU_MOD, 0x58, 0xe8 },
+	{ "CORE", MOD_PRM, CORE_MOD, 0x58, 0xf8 },
+	{ "SGX", MOD_PRM, OMAP3430ES2_SGX_MOD, 0x58, 0xe8 },
+	{ "WKUP", MOD_PRM, WKUP_MOD, 0xa0, 0xb0 },
+	{ "CCR", MOD_PRM, PLL_MOD, 0x40, 0x70 },
+	{ "DSS", MOD_PRM, OMAP3430_DSS_MOD, 0x58, 0xe8 },
+	{ "CAM", MOD_PRM, OMAP3430_CAM_MOD, 0x58, 0xe8 },
+	{ "PER", MOD_PRM, OMAP3430_PER_MOD, 0x58, 0xe8 },
+	{ "EMU", MOD_PRM, OMAP3430_EMU_MOD, 0x58, 0xe4 },
+	{ "GLBL", MOD_PRM, OMAP3430_GR_MOD, 0x20, 0xe4 },
+	{ "NEON", MOD_PRM, OMAP3430_NEON_MOD, 0x58, 0xe8 },
+	{ "USB", MOD_PRM, OMAP3430ES2_USBHOST_MOD, 0x58, 0xe8 },
+	{ "", 0, 0, 0, 0 },
+};
+
+#define PM_DBG_MAX_REG_SETS 4
+
+static void *pm_dbg_reg_set[PM_DBG_MAX_REG_SETS];
+
+static int pm_dbg_get_regset_size(void)
+{
+	static int regset_size;
+
+	if (regset_size == 0) {
+		int i = 0;
+
+		while (pm_dbg_reg_modules[i].name[0] != 0) {
+			regset_size += pm_dbg_reg_modules[i].high +
+				4 - pm_dbg_reg_modules[i].low;
+			i++;
+		}
+	}
+	return regset_size;
+}
+
+static int pm_dbg_show_regs(struct seq_file *s, void *unused)
+{
+	int i, j;
+	unsigned long val;
+	int reg_set = (int)s->private;
+	u32 *ptr;
+	void *store = NULL;
+	int regs;
+	int linefeed;
+
+	if (reg_set == 0) {
+		store = kmalloc(pm_dbg_get_regset_size(), GFP_KERNEL);
+		ptr = store;
+		pm_dbg_regset_store(ptr);
+	} else {
+		ptr = pm_dbg_reg_set[reg_set - 1];
+	}
+
+	i = 0;
+
+	while (pm_dbg_reg_modules[i].name[0] != 0) {
+		regs = 0;
+		linefeed = 0;
+		if (pm_dbg_reg_modules[i].type == MOD_CM)
+			seq_printf(s, "MOD: CM_%s (%08x)\n",
+				pm_dbg_reg_modules[i].name,
+				(u32)(OMAP3430_CM_BASE +
+				pm_dbg_reg_modules[i].offset));
+		else
+			seq_printf(s, "MOD: PRM_%s (%08x)\n",
+				pm_dbg_reg_modules[i].name,
+				(u32)(OMAP3430_PRM_BASE +
+				pm_dbg_reg_modules[i].offset));
+
+		for (j = pm_dbg_reg_modules[i].low;
+			j <= pm_dbg_reg_modules[i].high; j += 4) {
+			val = *(ptr++);
+			if (val != 0) {
+				regs++;
+				if (linefeed) {
+					seq_printf(s, "\n");
+					linefeed = 0;
+				}
+				seq_printf(s, "  %02x => %08lx", j, val);
+				if (regs % 4 == 0)
+					linefeed = 1;
+			}
+		}
+		seq_printf(s, "\n");
+		i++;
+	}
+
+	if (store != NULL)
+		kfree(store);
+
+	return 0;
+}
+
+static void pm_dbg_regset_store(u32 *ptr)
+{
+	int i, j;
+	u32 val;
+
+	i = 0;
+
+	while (pm_dbg_reg_modules[i].name[0] != 0) {
+		for (j = pm_dbg_reg_modules[i].low;
+			j <= pm_dbg_reg_modules[i].high; j += 4) {
+			if (pm_dbg_reg_modules[i].type == MOD_CM)
+				val = cm_read_mod_reg(
+					pm_dbg_reg_modules[i].offset, j);
+			else
+				val = prm_read_mod_reg(
+					pm_dbg_reg_modules[i].offset, j);
+			*(ptr++) = val;
+		}
+		i++;
+	}
+}
+
+int pm_dbg_regset_save(int reg_set)
+{
+	if (pm_dbg_reg_set[reg_set-1] == NULL)
+		return -EINVAL;
+
+	pm_dbg_regset_store(pm_dbg_reg_set[reg_set-1]);
+
+	return 0;
+}
+
 static const char pwrdm_state_names[][4] = {
 	"OFF",
 	"RET",
@@ -280,6 +438,11 @@ static int pm_dbg_open(struct inode *inode, struct file *file)
 	};
 }
 
+static int pm_dbg_reg_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, pm_dbg_show_regs, inode->i_private);
+}
+
 static const struct file_operations debug_fops = {
 	.open           = pm_dbg_open,
 	.read           = seq_read,
@@ -287,6 +450,40 @@ static const struct file_operations debug_fops = {
 	.release        = single_release,
 };
 
+static const struct file_operations debug_reg_fops = {
+	.open           = pm_dbg_reg_open,
+	.read           = seq_read,
+	.llseek         = seq_lseek,
+	.release        = single_release,
+};
+
+int pm_dbg_regset_init(int reg_set)
+{
+	char name[2];
+
+	if (!pm_dbg_init_done)
+		pm_dbg_init();
+
+	if (reg_set < 1 || reg_set > PM_DBG_MAX_REG_SETS ||
+		pm_dbg_reg_set[reg_set-1] != NULL)
+		return -EINVAL;
+
+	pm_dbg_reg_set[reg_set-1] =
+		kmalloc(pm_dbg_get_regset_size(), GFP_KERNEL);
+
+	if (pm_dbg_reg_set[reg_set-1] == NULL)
+		return -ENOMEM;
+
+	if (pm_dbg_dir != NULL) {
+		sprintf(name, "%d", reg_set);
+
+		(void) debugfs_create_file(name, S_IRUGO,
+			pm_dbg_dir, (void *)reg_set, &debug_reg_fops);
+	}
+
+	return 0;
+}
+
 static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
 {
 	int i;
@@ -304,8 +501,20 @@ static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
 
 static int __init pm_dbg_init(void)
 {
+	int i;
 	struct dentry *d;
+	char name[2];
 
+	if (pm_dbg_init_done)
+		return 0;
+
+	if (cpu_is_omap34xx())
+		pm_dbg_reg_modules = omap3_pm_reg_modules;
+	else {
+		printk(KERN_ERR "%s: only OMAP3 supported\n", __func__);
+		return -ENODEV;
+	}
+		
 	d = debugfs_create_dir("pm_debug", NULL);
 	if (IS_ERR(d))
 		return PTR_ERR(d);
@@ -317,11 +526,26 @@ static int __init pm_dbg_init(void)
 
 	pwrdm_for_each(pwrdms_setup, NULL);
 
+	pm_dbg_dir = debugfs_create_dir("registers", d);
+	if (IS_ERR(pm_dbg_dir))
+		return PTR_ERR(pm_dbg_dir);
+
+	(void) debugfs_create_file("current", S_IRUGO,
+		pm_dbg_dir, (void *)0, &debug_reg_fops);
+
+	for (i = 0; i < PM_DBG_MAX_REG_SETS; i++)
+		if (pm_dbg_reg_set[i] != NULL) {
+			sprintf(name, "%d", i+1);
+			(void) debugfs_create_file(name, S_IRUGO,
+				pm_dbg_dir, (void *)(i+1), &debug_reg_fops);
+
+		}
+
 	pm_dbg_init_done = 1;
 
 	return 0;
 }
-late_initcall(pm_dbg_init);
+arch_initcall(pm_dbg_init);
 
 #else
 void pm_dbg_update_time(struct powerdomain *pwrdm, int prev) {}

arch/arm/mach-omap2/pm.h

@@ -17,10 +17,14 @@
 extern void omap2_pm_dump(int mode, int resume, unsigned int us);
 extern int omap2_pm_debug;
 extern void pm_dbg_update_time(struct powerdomain *pwrdm, int prev);
+extern int pm_dbg_regset_save(int reg_set);
+extern int pm_dbg_regset_init(int reg_set);
 #else
 #define omap2_pm_dump(mode, resume, us)		do {} while (0);
 #define omap2_pm_debug				0
 #define pm_dbg_update_time(pwrdm, prev) do {} while (0);
+#define pm_dbg_regset_save(reg_set) do {} while (0);
+#define pm_dbg_regset_init(reg_set) do {} while (0);
 #endif /* CONFIG_PM_DEBUG */
 
 extern void omap24xx_idle_loop_suspend(void);