[PATCH v2] hwmon (pmbus/max20730): add device monitoring via debugfs

[Ugur Usug]

Add debugfs interface support for accessing device specific registers (MFR_VOUT_MIN, MFR_DEVSET1 and MFR_DEVSET2) and others including OPERATION, ON_OFF_CONFIG, SMB_ALERT_MASK, VOUT_MODE, VOUT_COMMAND and VOUT_MAX.

Signed-off-by: Ugur Usug <ugur.usug@xxxxxxxxxxxxxxxxxxx>
---
 drivers/hwmon/pmbus/max20730.c | 364 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 363 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/pmbus/max20730.c b/drivers/hwmon/pmbus/max20730.c
index a151a2b..aa5e2be 100644
--- a/drivers/hwmon/pmbus/max20730.c
+++ b/drivers/hwmon/pmbus/max20730.c
@@ -8,6 +8,7 @@
  */
 
 #include <linux/bits.h>
+#include <linux/debugfs.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
@@ -26,16 +27,368 @@ enum chips {
 	max20743
 };
 
+enum {
+	MAX20730_DEBUGFS_VOUT_MIN = 0,
+	MAX20730_DEBUGFS_FREQUENCY,
+	MAX20730_DEBUGFS_PG_DELAY,
+	MAX20730_DEBUGFS_INTERNAL_GAIN,
+	MAX20730_DEBUGFS_BOOT_VOLTAGE,
+	MAX20730_DEBUGFS_OUT_V_RAMP_RATE,
+	MAX20730_DEBUGFS_OC_PROTECT_MODE,
+	MAX20730_DEBUGFS_SS_TIMING,
+	MAX20730_DEBUGFS_IMAX,
+	MAX20730_DEBUGFS_OPERATION,
+	MAX20730_DEBUGFS_ON_OFF_CONFIG,
+	MAX20730_DEBUGFS_SMBALERT_MASK,
+	MAX20730_DEBUGFS_VOUT_MODE,
+	MAX20730_DEBUGFS_VOUT_COMMAND,
+	MAX20730_DEBUGFS_VOUT_MAX,
+	MAX20730_DEBUGFS_NUM_ENTRIES
+};
+
 struct max20730_data {
 	enum chips id;
 	struct pmbus_driver_info info;
 	struct mutex lock;	/* Used to protect against parallel writes */
 	u16 mfr_devset1;
+	u16 mfr_devset2;
+	u16 mfr_voutmin;
 };
 
 #define to_max20730_data(x)  container_of(x, struct max20730_data, info)
 
+#define PMBUS_SMB_ALERT_MASK	0x1B
+
+#define MAX20730_MFR_VOUT_MIN	0xd1
 #define MAX20730_MFR_DEVSET1	0xd2
+#define MAX20730_MFR_DEVSET2	0xd3
+
+#define MAX20730_MFR_VOUT_MIN_MASK		GENMASK(9, 0)
+#define MAX20730_MFR_VOUT_MIN_BIT_POS		0
+
+#define MAX20730_MFR_DEVSET1_RGAIN_MASK		(BIT(13) | BIT(14))
+#define MAX20730_MFR_DEVSET1_OTP_MASK		(BIT(11) | BIT(12))
+#define MAX20730_MFR_DEVSET1_VBOOT_MASK		(BIT(8) | BIT(9))
+#define MAX20730_MFR_DEVSET1_OCP_MASK		(BIT(5) | BIT(6))
+#define MAX20730_MFR_DEVSET1_FSW_MASK		GENMASK(4, 2)
+#define MAX20730_MFR_DEVSET1_TSTAT_MASK		(BIT(0) | BIT(1))
+
+#define MAX20730_MFR_DEVSET1_RGAIN_BIT_POS	13
+#define MAX20730_MFR_DEVSET1_OTP_BIT_POS	11
+#define MAX20730_MFR_DEVSET1_VBOOT_BIT_POS	8
+#define MAX20730_MFR_DEVSET1_OCP_BIT_POS	5
+#define MAX20730_MFR_DEVSET1_FSW_BIT_POS	2
+#define MAX20730_MFR_DEVSET1_TSTAT_BIT_POS	0
+
+#define MAX20730_MFR_DEVSET2_IMAX_MASK		GENMASK(10, 8)
+#define MAX20730_MFR_DEVSET2_VRATE		(BIT(6) | BIT(7))
+#define MAX20730_MFR_DEVSET2_OCPM_MASK		BIT(5)
+#define MAX20730_MFR_DEVSET2_SS_MASK		(BIT(0) | BIT(1))
+
+#define MAX20730_MFR_DEVSET2_IMAX_BIT_POS	8
+#define MAX20730_MFR_DEVSET2_VRATE_BIT_POS	6
+#define MAX20730_MFR_DEVSET2_OCPM_BIT_POS	5
+#define MAX20730_MFR_DEVSET2_SS_BIT_POS		0
+
+#define DEBUG_FS_DATA_MAX			8
+
+struct max20730_debugfs_data {
+	struct i2c_client *client;
+	int debugfs_entries[MAX20730_DEBUGFS_NUM_ENTRIES];
+};
+
+#define to_psu(x, y) container_of((x), \
+			struct max20730_debugfs_data, debugfs_entries[(y)])
+
+#ifdef CONFIG_DEBUG_FS
+static ssize_t max20730_debugfs_read(struct file *file, char __user *buf,
+				      size_t count, loff_t *ppos)
+{
+	int ret, len;
+	int *idxp = file->private_data;
+	int idx = *idxp;
+	struct max20730_debugfs_data *psu = to_psu(idxp, idx);
+	const struct pmbus_driver_info *info;
+	const struct max20730_data *data;
+	char tbuf[DEBUG_FS_DATA_MAX + 2] = { 0 };
+	u16 val;
+
+	info = pmbus_get_driver_info(psu->client);
+	data = to_max20730_data(info);
+
+	switch (idx) {
+	case MAX20730_DEBUGFS_VOUT_MIN:
+		len = snprintf(tbuf, 5, "%d", data->mfr_voutmin);
+		break;
+	case MAX20730_DEBUGFS_FREQUENCY:
+		val = (data->mfr_devset1 & MAX20730_MFR_DEVSET1_FSW_MASK)
+			>> MAX20730_MFR_DEVSET1_FSW_BIT_POS;
+		if (val == 0)
+			ret = 400;
+		else if (val == 1)
+			ret = 500;
+		else if (val == 2 || val == 3)
+			ret = 600;
+		else if (val == 4)
+			ret = 700;
+		else if (val == 5)
+			ret = 800;
+		else
+			ret = 900;
+		len = snprintf(tbuf, 4, "%d", ret);
+		break;
+	case MAX20730_DEBUGFS_PG_DELAY:
+		val = (data->mfr_devset1 & MAX20730_MFR_DEVSET1_TSTAT_MASK)
+			>> MAX20730_MFR_DEVSET1_TSTAT_BIT_POS;
+
+		if (val == 0)
+			strcpy(tbuf, "2000");
+		else if (val == 1)
+			strcpy(tbuf, "125");
+		else if (val == 2)
+			strcpy(tbuf, "62.5");
+		else
+			strcpy(tbuf, "32");
+		len = strnlen(tbuf, DEBUG_FS_DATA_MAX);
+		break;
+
+	case MAX20730_DEBUGFS_INTERNAL_GAIN:
+		val = (data->mfr_devset1 & MAX20730_MFR_DEVSET1_RGAIN_MASK)
+			>> MAX20730_MFR_DEVSET1_RGAIN_BIT_POS;
+
+		if (data->id == max20734) {
+			/* AN6209 */
+			if (val == 0)
+				strcpy(tbuf, "0.8");
+			else if (val == 1)
+				strcpy(tbuf, "3.2");
+			else if (val == 2)
+				strcpy(tbuf, "1.6");
+			else
+				strcpy(tbuf, "6.4");
+		} else if (data->id == max20730 || data->id == max20710) {
+			/* AN6042 or AN6140 */
+			if (val == 0)
+				strcpy(tbuf, "0.9");
+			else if (val == 1)
+				strcpy(tbuf, "3.6");
+			else if (val == 2)
+				strcpy(tbuf, "1.8");
+			else
+				strcpy(tbuf, "7.2");
+		} else if (data->id == max20743) {
+			/* AN6042 */
+			if (val == 0)
+				strcpy(tbuf, "0.45");
+			else if (val == 1)
+				strcpy(tbuf, "1.8");
+			else if (val == 2)
+				strcpy(tbuf, "0.9");
+			else
+				strcpy(tbuf, "3.6");
+		} else
+			return -EINVAL;
+
+		len = strnlen(tbuf, DEBUG_FS_DATA_MAX);
+		break;
+	case MAX20730_DEBUGFS_BOOT_VOLTAGE:
+		val = (data->mfr_devset1 & MAX20730_MFR_DEVSET1_VBOOT_MASK)
+			>> MAX20730_MFR_DEVSET1_VBOOT_BIT_POS;
+
+		if (val == 0)
+			strcpy(tbuf, "0.6484");
+		else if (val == 1)
+			strcpy(tbuf, "0.8984");
+		else if (val == 2)
+			strcpy(tbuf, "1.0");
+		else
+			return -EINVAL;
+
+		len = strnlen(tbuf, DEBUG_FS_DATA_MAX);
+		break;
+	case MAX20730_DEBUGFS_OUT_V_RAMP_RATE:
+		val = (data->mfr_devset2 & MAX20730_MFR_DEVSET2_VRATE)
+			>> MAX20730_MFR_DEVSET2_VRATE_BIT_POS;
+
+		if (val == 0)
+			ret = 4;
+		else if (val == 1)
+			ret = 2;
+		else if (val == 2)
+			ret = 1;
+		else
+			return -EINVAL;
+
+		len = snprintf(tbuf, 2, "%d", ret);
+		break;
+	case MAX20730_DEBUGFS_OC_PROTECT_MODE:
+		ret = (data->mfr_devset2 & MAX20730_MFR_DEVSET2_OCPM_MASK)
+			>> MAX20730_MFR_DEVSET2_OCPM_BIT_POS;
+		len = snprintf(tbuf, 2, "%d", ret);
+		break;
+	case MAX20730_DEBUGFS_SS_TIMING:
+		val = (data->mfr_devset2 & MAX20730_MFR_DEVSET2_SS_MASK)
+			>> MAX20730_MFR_DEVSET2_SS_BIT_POS;
+
+		if (val == 0)
+			strcpy(tbuf, "0.75");
+		else if (val == 1)
+			strcpy(tbuf, "1.5");
+		else if (val == 2)
+			strcpy(tbuf, "3");
+		else
+			strcpy(tbuf, "6");
+
+		len = strnlen(tbuf, DEBUG_FS_DATA_MAX);
+		break;
+	case MAX20730_DEBUGFS_IMAX:
+		ret = (data->mfr_devset2 & MAX20730_MFR_DEVSET2_IMAX_MASK)
+			>> MAX20730_MFR_DEVSET2_IMAX_BIT_POS;
+		len = snprintf(tbuf, 2, "%d", ret);
+		break;
+	case MAX20730_DEBUGFS_OPERATION:
+		ret = i2c_smbus_read_byte_data(psu->client, PMBUS_OPERATION);
+		if (ret < 0)
+			return ret;
+		len = snprintf(tbuf, 2, "%d", ret);
+		break;
+	case MAX20730_DEBUGFS_ON_OFF_CONFIG:
+		ret = i2c_smbus_read_byte_data(psu->client, PMBUS_ON_OFF_CONFIG);
+		if (ret < 0)
+			return ret;
+		len = snprintf(tbuf, 2, "%d", ret);
+		break;
+	case MAX20730_DEBUGFS_SMBALERT_MASK:
+		ret = i2c_smbus_read_word_data(psu->client,
+							PMBUS_SMB_ALERT_MASK);
+		if (ret < 0)
+			return ret;
+		len = snprintf(tbuf, 3, "%d", ret);
+		break;
+	case MAX20730_DEBUGFS_VOUT_MODE:
+		ret = i2c_smbus_read_byte_data(psu->client, PMBUS_VOUT_MODE);
+		if (ret < 0)
+			return ret;
+		len = snprintf(tbuf, 2, "%d", ret);
+		break;
+	case MAX20730_DEBUGFS_VOUT_COMMAND:
+		ret = i2c_smbus_read_word_data(psu->client, PMBUS_VOUT_COMMAND);
+		if (ret < 0)
+			return ret;
+		len = snprintf(tbuf, 3, "%d", ret);
+		break;
+	case MAX20730_DEBUGFS_VOUT_MAX:
+		ret = i2c_smbus_read_word_data(psu->client, PMBUS_VOUT_MAX);
+		if (ret < 0)
+			return ret;
+		len = snprintf(tbuf, 3, "%d", ret);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	tbuf[len] = '\n';
+	len += 2;
+
+	return simple_read_from_buffer(buf, count, ppos, tbuf, len);
+}
+
+static const struct file_operations max20730_fops = {
+	.llseek = noop_llseek,
+	.read = max20730_debugfs_read,
+	.write = NULL,
+	.open = simple_open,
+};
+
+static int max20730_init_debugfs(struct i2c_client *client,
+				struct max20730_data *data)
+{
+	int ret, i;
+	struct dentry *debugfs;
+	struct dentry *max20730_dir;
+	struct max20730_debugfs_data *psu;
+
+	ret = i2c_smbus_read_word_data(client, MAX20730_MFR_DEVSET2);
+	if (ret < 0)
+		return ret;
+	data->mfr_devset2 = ret;
+
+	ret = i2c_smbus_read_word_data(client, MAX20730_MFR_VOUT_MIN);
+	if (ret < 0)
+		return ret;
+	data->mfr_voutmin = ret;
+
+	psu = devm_kzalloc(&client->dev, sizeof(*psu), GFP_KERNEL);
+	if (!psu)
+		return -ENOMEM;
+	psu->client = client;
+
+	debugfs = pmbus_get_debugfs_dir(client);
+	if (!debugfs)
+		return -ENOENT;
+
+	max20730_dir = debugfs_create_dir(client->name, debugfs);
+	if (!max20730_dir)
+		return -ENOENT;
+
+	for (i = 0; i < MAX20730_DEBUGFS_NUM_ENTRIES; ++i)
+		psu->debugfs_entries[i] = i;
+
+	debugfs_create_file("vout_min", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_VOUT_MIN],
+			    &max20730_fops);
+	debugfs_create_file("frequency", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_FREQUENCY],
+			    &max20730_fops);
+	debugfs_create_file("power_good_delay", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_PG_DELAY],
+			    &max20730_fops);
+	debugfs_create_file("internal_gain", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_INTERNAL_GAIN],
+			    &max20730_fops);
+	debugfs_create_file("boot_voltage", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_BOOT_VOLTAGE],
+			    &max20730_fops);
+	debugfs_create_file("out_voltage_ramp_rate", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_OUT_V_RAMP_RATE],
+			    &max20730_fops);
+	debugfs_create_file("oc_protection_mode", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_OC_PROTECT_MODE],
+			    &max20730_fops);
+	debugfs_create_file("soft_start_timing", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_SS_TIMING],
+			    &max20730_fops);
+	debugfs_create_file("imax", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_IMAX],
+			    &max20730_fops);
+	debugfs_create_file("operation", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_OPERATION],
+			    &max20730_fops);
+	debugfs_create_file("on_off_config", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_ON_OFF_CONFIG],
+			    &max20730_fops);
+	debugfs_create_file("smbalert_mask", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_SMBALERT_MASK],
+			    &max20730_fops);
+	debugfs_create_file("vout_mode", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_VOUT_MODE],
+			    &max20730_fops);
+	debugfs_create_file("vout_command", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_VOUT_COMMAND],
+			    &max20730_fops);
+	debugfs_create_file("vout_max", 0444, max20730_dir,
+			    &psu->debugfs_entries[MAX20730_DEBUGFS_VOUT_MAX],
+			    &max20730_fops);
+
+	return 0;
+}
+#else
+static int max20730_init_debugfs(struct i2c_client *client,
+				struct max20730_data *data)
+{
+	return 0;
+}
+#endif /* CONFIG_DEBUG_FS */
 
 /*
  * Convert discreet value to direct data format. Strictly speaking, all passed
@@ -370,7 +723,16 @@ static int max20730_probe(struct i2c_client *client,
 		return ret;
 	data->mfr_devset1 = ret;
 
-	return pmbus_do_probe(client, id, &data->info);
+	ret = pmbus_do_probe(client, id, &data->info);
+	if (ret < 0)
+		return ret;
+
+	ret = max20730_init_debugfs(client, data);
+	if (ret)
+		dev_warn(dev, "Failed to register debugfs: %d\n",
+			 ret);
+
+	return 0;
 }
 
 static const struct i2c_device_id max20730_id[] = {
-- 
2.7.4