soc: mediatek: SVS: add debug commands

The purpose of SVS is to help find the suitable voltages
for DVFS. Therefore, if SVS bank voltages are concerned
to be wrong, we can show/disable SVS bank voltages by
this patch.

Signed-off-by: Roger Lu <roger.lu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Link: https://lore.kernel.org/r/20220516004311.18358-6-roger.lu@mediatek.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

drivers/soc/mediatek/mtk-svs.c

@@ -7,6 +7,7 @@
 #include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/cpuidle.h>
+#include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
@@ -23,6 +24,7 @@
 #include <linux/pm_opp.h>
 #include <linux/pm_runtime.h>
 #include <linux/regulator/consumer.h>
+#include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/thermal.h>
@@ -69,6 +71,39 @@
 
 static DEFINE_SPINLOCK(svs_lock);
 
+#define debug_fops_ro(name)						\
+	static int svs_##name##_debug_open(struct inode *inode,		\
+					   struct file *filp)		\
+	{								\
+		return single_open(filp, svs_##name##_debug_show,	\
+				   inode->i_private);			\
+	}								\
+	static const struct file_operations svs_##name##_debug_fops = {	\
+		.owner = THIS_MODULE,					\
+		.open = svs_##name##_debug_open,			\
+		.read = seq_read,					\
+		.llseek = seq_lseek,					\
+		.release = single_release,				\
+	}
+
+#define debug_fops_rw(name)						\
+	static int svs_##name##_debug_open(struct inode *inode,		\
+					   struct file *filp)		\
+	{								\
+		return single_open(filp, svs_##name##_debug_show,	\
+				   inode->i_private);			\
+	}								\
+	static const struct file_operations svs_##name##_debug_fops = {	\
+		.owner = THIS_MODULE,					\
+		.open = svs_##name##_debug_open,			\
+		.read = seq_read,					\
+		.write = svs_##name##_debug_write,			\
+		.llseek = seq_lseek,					\
+		.release = single_release,				\
+	}
+
+#define svs_dentry_data(name)	{__stringify(name), &svs_##name##_debug_fops}
+
 /**
  * enum svsb_phase - svs bank phase enumeration
  * @SVSB_PHASE_ERROR: svs bank encounters unexpected condition
@@ -268,6 +303,7 @@ struct svs_platform_data {
  * @tzone_name: thermal zone name
  * @phase: bank current phase
  * @volt_od: bank voltage overdrive
+ * @reg_data: bank register data in different phase for debug purpose
  * @pm_runtime_enabled_count: bank pm runtime enabled count
  * @mode_support: bank mode support.
  * @freq_base: reference frequency for bank init
@@ -326,6 +362,7 @@ struct svs_bank {
 	char *tzone_name;
 	enum svsb_phase phase;
 	s32 volt_od;
+	u32 reg_data[SVSB_PHASE_MAX][SVS_REG_MAX];
 	u32 pm_runtime_enabled_count;
 	u32 mode_support;
 	u32 freq_base;
@@ -467,6 +504,220 @@ static int svs_adjust_pm_opp_volts(struct svs_bank *svsb)
 	return ret;
 }
 
+static int svs_dump_debug_show(struct seq_file *m, void *p)
+{
+	struct svs_platform *svsp = (struct svs_platform *)m->private;
+	struct svs_bank *svsb;
+	unsigned long svs_reg_addr;
+	u32 idx, i, j, bank_id;
+
+	for (i = 0; i < svsp->efuse_max; i++)
+		if (svsp->efuse && svsp->efuse[i])
+			seq_printf(m, "M_HW_RES%d = 0x%08x\n",
+				   i, svsp->efuse[i]);
+
+	for (i = 0; i < svsp->tefuse_max; i++)
+		if (svsp->tefuse)
+			seq_printf(m, "THERMAL_EFUSE%d = 0x%08x\n",
+				   i, svsp->tefuse[i]);
+
+	for (bank_id = 0, idx = 0; idx < svsp->bank_max; idx++, bank_id++) {
+		svsb = &svsp->banks[idx];
+
+		for (i = SVSB_PHASE_INIT01; i <= SVSB_PHASE_MON; i++) {
+			seq_printf(m, "Bank_number = %u\n", bank_id);
+
+			if (i == SVSB_PHASE_INIT01 || i == SVSB_PHASE_INIT02)
+				seq_printf(m, "mode = init%d\n", i);
+			else if (i == SVSB_PHASE_MON)
+				seq_puts(m, "mode = mon\n");
+			else
+				seq_puts(m, "mode = error\n");
+
+			for (j = DESCHAR; j < SVS_REG_MAX; j++) {
+				svs_reg_addr = (unsigned long)(svsp->base +
+							       svsp->regs[j]);
+				seq_printf(m, "0x%08lx = 0x%08x\n",
+					   svs_reg_addr, svsb->reg_data[i][j]);
+			}
+		}
+	}
+
+	return 0;
+}
+
+debug_fops_ro(dump);
+
+static int svs_enable_debug_show(struct seq_file *m, void *v)
+{
+	struct svs_bank *svsb = (struct svs_bank *)m->private;
+
+	switch (svsb->phase) {
+	case SVSB_PHASE_ERROR:
+		seq_puts(m, "disabled\n");
+		break;
+	case SVSB_PHASE_INIT01:
+		seq_puts(m, "init1\n");
+		break;
+	case SVSB_PHASE_INIT02:
+		seq_puts(m, "init2\n");
+		break;
+	case SVSB_PHASE_MON:
+		seq_puts(m, "mon mode\n");
+		break;
+	default:
+		seq_puts(m, "unknown\n");
+		break;
+	}
+
+	return 0;
+}
+
+static ssize_t svs_enable_debug_write(struct file *filp,
+				      const char __user *buffer,
+				      size_t count, loff_t *pos)
+{
+	struct svs_bank *svsb = file_inode(filp)->i_private;
+	struct svs_platform *svsp = dev_get_drvdata(svsb->dev);
+	unsigned long flags;
+	int enabled, ret;
+	char *buf = NULL;
+
+	if (count >= PAGE_SIZE)
+		return -EINVAL;
+
+	buf = (char *)memdup_user_nul(buffer, count);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	ret = kstrtoint(buf, 10, &enabled);
+	if (ret)
+		return ret;
+
+	if (!enabled) {
+		spin_lock_irqsave(&svs_lock, flags);
+		svsp->pbank = svsb;
+		svsb->mode_support = SVSB_MODE_ALL_DISABLE;
+		svs_switch_bank(svsp);
+		svs_writel_relaxed(svsp, SVSB_EN_OFF, SVSEN);
+		svs_writel_relaxed(svsp, SVSB_INTSTS_CLEAN, INTSTS);
+		spin_unlock_irqrestore(&svs_lock, flags);
+
+		svsb->phase = SVSB_PHASE_ERROR;
+		svs_adjust_pm_opp_volts(svsb);
+	}
+
+	kfree(buf);
+
+	return count;
+}
+
+debug_fops_rw(enable);
+
+static int svs_status_debug_show(struct seq_file *m, void *v)
+{
+	struct svs_bank *svsb = (struct svs_bank *)m->private;
+	struct dev_pm_opp *opp;
+	int tzone_temp = 0, ret;
+	u32 i;
+
+	ret = thermal_zone_get_temp(svsb->tzd, &tzone_temp);
+	if (ret)
+		seq_printf(m, "%s: temperature ignore\n", svsb->name);
+	else
+		seq_printf(m, "%s: temperature = %d\n", svsb->name, tzone_temp);
+
+	for (i = 0; i < svsb->opp_count; i++) {
+		opp = dev_pm_opp_find_freq_exact(svsb->opp_dev,
+						 svsb->opp_dfreq[i], true);
+		if (IS_ERR(opp)) {
+			seq_printf(m, "%s: cannot find freq = %u (%ld)\n",
+				   svsb->name, svsb->opp_dfreq[i],
+				   PTR_ERR(opp));
+			return PTR_ERR(opp);
+		}
+
+		seq_printf(m, "opp_freq[%02u]: %u, opp_volt[%02u]: %lu, ",
+			   i, svsb->opp_dfreq[i], i,
+			   dev_pm_opp_get_voltage(opp));
+		seq_printf(m, "svsb_volt[%02u]: 0x%x, freq_pct[%02u]: %u\n",
+			   i, svsb->volt[i], i, svsb->freq_pct[i]);
+		dev_pm_opp_put(opp);
+	}
+
+	return 0;
+}
+
+debug_fops_ro(status);
+
+static int svs_create_debug_cmds(struct svs_platform *svsp)
+{
+	struct svs_bank *svsb;
+	struct dentry *svs_dir, *svsb_dir, *file_entry;
+	const char *d = "/sys/kernel/debug/svs";
+	u32 i, idx;
+
+	struct svs_dentry {
+		const char *name;
+		const struct file_operations *fops;
+	};
+
+	struct svs_dentry svs_entries[] = {
+		svs_dentry_data(dump),
+	};
+
+	struct svs_dentry svsb_entries[] = {
+		svs_dentry_data(enable),
+		svs_dentry_data(status),
+	};
+
+	svs_dir = debugfs_create_dir("svs", NULL);
+	if (IS_ERR(svs_dir)) {
+		dev_err(svsp->dev, "cannot create %s: %ld\n",
+			d, PTR_ERR(svs_dir));
+		return PTR_ERR(svs_dir);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(svs_entries); i++) {
+		file_entry = debugfs_create_file(svs_entries[i].name, 0664,
+						 svs_dir, svsp,
+						 svs_entries[i].fops);
+		if (IS_ERR(file_entry)) {
+			dev_err(svsp->dev, "cannot create %s/%s: %ld\n",
+				d, svs_entries[i].name, PTR_ERR(file_entry));
+			return PTR_ERR(file_entry);
+		}
+	}
+
+	for (idx = 0; idx < svsp->bank_max; idx++) {
+		svsb = &svsp->banks[idx];
+
+		if (svsb->mode_support == SVSB_MODE_ALL_DISABLE)
+			continue;
+
+		svsb_dir = debugfs_create_dir(svsb->name, svs_dir);
+		if (IS_ERR(svsb_dir)) {
+			dev_err(svsp->dev, "cannot create %s/%s: %ld\n",
+				d, svsb->name, PTR_ERR(svsb_dir));
+			return PTR_ERR(svsb_dir);
+		}
+
+		for (i = 0; i < ARRAY_SIZE(svsb_entries); i++) {
+			file_entry = debugfs_create_file(svsb_entries[i].name,
+							 0664, svsb_dir, svsb,
+							 svsb_entries[i].fops);
+			if (IS_ERR(file_entry)) {
+				dev_err(svsp->dev, "no %s/%s/%s?: %ld\n",
+					d, svsb->name, svsb_entries[i].name,
+					PTR_ERR(file_entry));
+				return PTR_ERR(file_entry);
+			}
+		}
+	}
+
+	return 0;
+}
+
 static u32 interpolate(u32 f0, u32 f1, u32 v0, u32 v1, u32 fx)
 {
 	u32 vx;
@@ -591,6 +842,16 @@ static void svs_set_bank_phase(struct svs_platform *svsp,
 	}
 }
 
+static inline void svs_save_bank_register_data(struct svs_platform *svsp,
+					       enum svsb_phase phase)
+{
+	struct svs_bank *svsb = svsp->pbank;
+	enum svs_reg_index rg_i;
+
+	for (rg_i = DESCHAR; rg_i < SVS_REG_MAX; rg_i++)
+		svsb->reg_data[phase][rg_i] = svs_readl_relaxed(svsp, rg_i);
+}
+
 static inline void svs_error_isr_handler(struct svs_platform *svsp)
 {
 	struct svs_bank *svsb = svsp->pbank;
@@ -605,6 +866,8 @@ static inline void svs_error_isr_handler(struct svs_platform *svsp)
 		svs_readl_relaxed(svsp, SMSTATE1));
 	dev_err(svsb->dev, "TEMP = 0x%08x\n", svs_readl_relaxed(svsp, TEMP));
 
+	svs_save_bank_register_data(svsp, SVSB_PHASE_ERROR);
+
 	svsb->phase = SVSB_PHASE_ERROR;
 	svs_writel_relaxed(svsp, SVSB_EN_OFF, SVSEN);
 	svs_writel_relaxed(svsp, SVSB_INTSTS_CLEAN, INTSTS);
@@ -619,6 +882,8 @@ static inline void svs_init01_isr_handler(struct svs_platform *svsp)
 		 svs_readl_relaxed(svsp, VDESIGN30),
 		 svs_readl_relaxed(svsp, DCVALUES));
 
+	svs_save_bank_register_data(svsp, SVSB_PHASE_INIT01);
+
 	svsb->phase = SVSB_PHASE_INIT01;
 	svsb->dc_voffset_in = ~(svs_readl_relaxed(svsp, DCVALUES) &
 				GENMASK(15, 0)) + 1;
@@ -644,6 +909,8 @@ static inline void svs_init02_isr_handler(struct svs_platform *svsp)
 		 svs_readl_relaxed(svsp, VOP30),
 		 svs_readl_relaxed(svsp, DCVALUES));
 
+	svs_save_bank_register_data(svsp, SVSB_PHASE_INIT02);
+
 	svsb->phase = SVSB_PHASE_INIT02;
 	svsb->get_volts(svsp);
 
@@ -655,6 +922,8 @@ static inline void svs_mon_mode_isr_handler(struct svs_platform *svsp)
 {
 	struct svs_bank *svsb = svsp->pbank;
 
+	svs_save_bank_register_data(svsp, SVSB_PHASE_MON);
+
 	svsb->phase = SVSB_PHASE_MON;
 	svsb->get_volts(svsp);
 
@@ -1626,6 +1895,12 @@ static int svs_probe(struct platform_device *pdev)
 		goto svs_probe_iounmap;
 	}
 
+	ret = svs_create_debug_cmds(svsp);
+	if (ret) {
+		dev_err(svsp->dev, "svs create debug cmds fail: %d\n", ret);
+		goto svs_probe_iounmap;
+	}
+
 	return 0;
 
 svs_probe_iounmap: