1 files changed, 318 insertions, 139 deletions

diff --git a/drivers/hwmon/max31827.c b/drivers/hwmon/max31827.c
index 602f4e4f81ff..9b2e56c040df 100644
--- a/drivers/hwmon/max31827.c
+++ b/drivers/hwmon/max31827.c
@@ -10,8 +10,9 @@
 #include <linux/delay.h>
 #include <linux/hwmon.h>
 #include <linux/i2c.h>
-#include <linux/mutex.h>
+#include <linux/of_device.h>
 #include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
 
 #define MAX31827_T_REG			0x0
 #define MAX31827_CONFIGURATION_REG	0x2
@@ -22,30 +23,85 @@
 
 #define MAX31827_CONFIGURATION_1SHOT_MASK	BIT(0)
 #define MAX31827_CONFIGURATION_CNV_RATE_MASK	GENMASK(3, 1)
+#define MAX31827_CONFIGURATION_PEC_EN_MASK	BIT(4)
+#define MAX31827_CONFIGURATION_TIMEOUT_MASK	BIT(5)
+#define MAX31827_CONFIGURATION_RESOLUTION_MASK	GENMASK(7, 6)
+#define MAX31827_CONFIGURATION_ALRM_POL_MASK	BIT(8)
+#define MAX31827_CONFIGURATION_COMP_INT_MASK	BIT(9)
+#define MAX31827_CONFIGURATION_FLT_Q_MASK	GENMASK(11, 10)
 #define MAX31827_CONFIGURATION_U_TEMP_STAT_MASK	BIT(14)
 #define MAX31827_CONFIGURATION_O_TEMP_STAT_MASK	BIT(15)
 
-#define MAX31827_12_BIT_CNV_TIME	141
+#define MAX31827_ALRM_POL_LOW	0x0
+#define MAX31827_ALRM_POL_HIGH	0x1
+#define MAX31827_FLT_Q_1	0x0
+#define MAX31827_FLT_Q_4	0x2
 
-#define MAX31827_CNV_1_DIV_64_HZ	0x1
-#define MAX31827_CNV_1_DIV_32_HZ	0x2
-#define MAX31827_CNV_1_DIV_16_HZ	0x3
-#define MAX31827_CNV_1_DIV_4_HZ		0x4
-#define MAX31827_CNV_1_HZ		0x5
-#define MAX31827_CNV_4_HZ		0x6
-#define MAX31827_CNV_8_HZ		0x7
+#define MAX31827_8_BIT_CNV_TIME		9
+#define MAX31827_9_BIT_CNV_TIME		18
+#define MAX31827_10_BIT_CNV_TIME	35
+#define MAX31827_12_BIT_CNV_TIME	140
 
 #define MAX31827_16_BIT_TO_M_DGR(x)	(sign_extend32(x, 15) * 1000 / 16)
 #define MAX31827_M_DGR_TO_16_BIT(x)	(((x) << 4) / 1000)
 #define MAX31827_DEVICE_ENABLE(x)	((x) ? 0xA : 0x0)
 
+/*
+ * The enum passed in the .data pointer of struct of_device_id must
+ * start with a value != 0 since that is a requirement for using
+ * device_get_match_data().
+ */
+enum chips { max31827 = 1, max31828, max31829 };
+
+enum max31827_cnv {
+	MAX31827_CNV_1_DIV_64_HZ = 1,
+	MAX31827_CNV_1_DIV_32_HZ,
+	MAX31827_CNV_1_DIV_16_HZ,
+	MAX31827_CNV_1_DIV_4_HZ,
+	MAX31827_CNV_1_HZ,
+	MAX31827_CNV_4_HZ,
+	MAX31827_CNV_8_HZ,
+};
+
+static const u16 max31827_conversions[] = {
+	[MAX31827_CNV_1_DIV_64_HZ] = 64000,
+	[MAX31827_CNV_1_DIV_32_HZ] = 32000,
+	[MAX31827_CNV_1_DIV_16_HZ] = 16000,
+	[MAX31827_CNV_1_DIV_4_HZ] = 4000,
+	[MAX31827_CNV_1_HZ] = 1000,
+	[MAX31827_CNV_4_HZ] = 250,
+	[MAX31827_CNV_8_HZ] = 125,
+};
+
+enum max31827_resolution {
+	MAX31827_RES_8_BIT = 0,
+	MAX31827_RES_9_BIT,
+	MAX31827_RES_10_BIT,
+	MAX31827_RES_12_BIT,
+};
+
+static const u16 max31827_resolutions[] = {
+	[MAX31827_RES_8_BIT] = 1000,
+	[MAX31827_RES_9_BIT] = 500,
+	[MAX31827_RES_10_BIT] = 250,
+	[MAX31827_RES_12_BIT] = 62,
+};
+
+static const u16 max31827_conv_times[] = {
+	[MAX31827_RES_8_BIT] = MAX31827_8_BIT_CNV_TIME,
+	[MAX31827_RES_9_BIT] = MAX31827_9_BIT_CNV_TIME,
+	[MAX31827_RES_10_BIT] = MAX31827_10_BIT_CNV_TIME,
+	[MAX31827_RES_12_BIT] = MAX31827_12_BIT_CNV_TIME,
+};
+
 struct max31827_state {
 	/*
 	 * Prevent simultaneous access to the i2c client.
 	 */
-	struct mutex lock;
 	struct regmap *regmap;
 	bool enable;
+	unsigned int resolution;
+	unsigned int update_interval;
 };
 
 static const struct regmap_config max31827_regmap = {
@@ -54,49 +110,54 @@ static const struct regmap_config max31827_regmap = {
 	.max_register = 0xA,
 };
 
-static int write_alarm_val(struct max31827_state *st, unsigned int reg,
-			   long val)
+static int shutdown_write(struct max31827_state *st, unsigned int reg,
+			  unsigned int mask, unsigned int val)
 {
 	unsigned int cfg;
-	unsigned int tmp;
+	unsigned int cnv_rate;
 	int ret;
 
-	val = MAX31827_M_DGR_TO_16_BIT(val);
-
 	/*
-	 * Before the Temperature Threshold Alarm and Alarm Hysteresis Threshold
-	 * register values are changed over I2C, the part must be in shutdown
-	 * mode.
-	 *
-	 * Mutex is used to ensure, that some other process doesn't change the
-	 * configuration register.
+	 * Before the Temperature Threshold Alarm, Alarm Hysteresis Threshold
+	 * and Resolution bits from Configuration register are changed over I2C,
+	 * the part must be in shutdown mode.
 	 */
-	mutex_lock(&st->lock);
-
 	if (!st->enable) {
-		ret = regmap_write(st->regmap, reg, val);
-		goto unlock;
+		if (!mask)
+			return regmap_write(st->regmap, reg, val);
+		return regmap_update_bits(st->regmap, reg, mask, val);
 	}
 
 	ret = regmap_read(st->regmap, MAX31827_CONFIGURATION_REG, &cfg);
 	if (ret)
-		goto unlock;
+		return ret;
 
-	tmp = cfg & ~(MAX31827_CONFIGURATION_1SHOT_MASK |
+	cnv_rate = MAX31827_CONFIGURATION_CNV_RATE_MASK & cfg;
+	cfg = cfg & ~(MAX31827_CONFIGURATION_1SHOT_MASK |
 		      MAX31827_CONFIGURATION_CNV_RATE_MASK);
-	ret = regmap_write(st->regmap, MAX31827_CONFIGURATION_REG, tmp);
+	ret = regmap_write(st->regmap, MAX31827_CONFIGURATION_REG, cfg);
 	if (ret)
-		goto unlock;
+		return ret;
+
+	if (!mask)
+		ret = regmap_write(st->regmap, reg, val);
+	else
+		ret = regmap_update_bits(st->regmap, reg, mask, val);
 
-	ret = regmap_write(st->regmap, reg, val);
 	if (ret)
-		goto unlock;
+		return ret;
 
-	ret = regmap_write(st->regmap, MAX31827_CONFIGURATION_REG, cfg);
+	return regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
+				  MAX31827_CONFIGURATION_CNV_RATE_MASK,
+				  cnv_rate);
+}
 
-unlock:
-	mutex_unlock(&st->lock);
-	return ret;
+static int write_alarm_val(struct max31827_state *st, unsigned int reg,
+			   long val)
+{
+	val = MAX31827_M_DGR_TO_16_BIT(val);
+
+	return shutdown_write(st, reg, 0, val);
 }
 
 static umode_t max31827_is_visible(const void *state,
@@ -149,29 +210,26 @@ static int max31827_read(struct device *dev, enum hwmon_sensor_types type,
 
 			break;
 		case hwmon_temp_input:
-			mutex_lock(&st->lock);
-
 			if (!st->enable) {
-				/*
-				 * This operation requires mutex protection,
-				 * because the chip configuration should not
-				 * be changed during the conversion process.
-				 */
-
 				ret = regmap_update_bits(st->regmap,
 							 MAX31827_CONFIGURATION_REG,
 							 MAX31827_CONFIGURATION_1SHOT_MASK,
 							 1);
-				if (ret) {
-					mutex_unlock(&st->lock);
+				if (ret)
 					return ret;
-				}
-
-				msleep(MAX31827_12_BIT_CNV_TIME);
+				msleep(max31827_conv_times[st->resolution]);
 			}
-			ret = regmap_read(st->regmap, MAX31827_T_REG, &uval);
 
-			mutex_unlock(&st->lock);
+			/*
+			 * For 12-bit resolution the conversion time is 140 ms,
+			 * thus an additional 15 ms is needed to complete the
+			 * conversion: 125 ms + 15 ms = 140 ms
+			 */
+			if (max31827_resolutions[st->resolution] == 12 &&
+			    st->update_interval == 125)
+				usleep_range(15000, 20000);
+
+			ret = regmap_read(st->regmap, MAX31827_T_REG, &uval);
 
 			if (ret)
 				break;
@@ -243,32 +301,7 @@ static int max31827_read(struct device *dev, enum hwmon_sensor_types type,
 
 			uval = FIELD_GET(MAX31827_CONFIGURATION_CNV_RATE_MASK,
 					 uval);
-			switch (uval) {
-			case MAX31827_CNV_1_DIV_64_HZ:
-				*val = 64000;
-				break;
-			case MAX31827_CNV_1_DIV_32_HZ:
-				*val = 32000;
-				break;
-			case MAX31827_CNV_1_DIV_16_HZ:
-				*val = 16000;
-				break;
-			case MAX31827_CNV_1_DIV_4_HZ:
-				*val = 4000;
-				break;
-			case MAX31827_CNV_1_HZ:
-				*val = 1000;
-				break;
-			case MAX31827_CNV_4_HZ:
-				*val = 250;
-				break;
-			case MAX31827_CNV_8_HZ:
-				*val = 125;
-				break;
-			default:
-				*val = 0;
-				break;
-			}
+			*val = max31827_conversions[uval];
 		}
 		break;
 
@@ -284,6 +317,7 @@ static int max31827_write(struct device *dev, enum hwmon_sensor_types type,
 			  u32 attr, int channel, long val)
 {
 	struct max31827_state *st = dev_get_drvdata(dev);
+	int res = 1;
 	int ret;
 
 	switch (type) {
@@ -293,7 +327,6 @@ static int max31827_write(struct device *dev, enum hwmon_sensor_types type,
 			if (val >> 1)
 				return -EINVAL;
 
-			mutex_lock(&st->lock);
 			/**
 			 * The chip should not be enabled while a conversion is
 			 * performed. Neither should the chip be enabled when
@@ -302,15 +335,11 @@ static int max31827_write(struct device *dev, enum hwmon_sensor_types type,
 
 			st->enable = val;
 
-			ret = regmap_update_bits(st->regmap,
-						 MAX31827_CONFIGURATION_REG,
-						 MAX31827_CONFIGURATION_1SHOT_MASK |
-						 MAX31827_CONFIGURATION_CNV_RATE_MASK,
-						 MAX31827_DEVICE_ENABLE(val));
-
-			mutex_unlock(&st->lock);
-
-			return ret;
+			return regmap_update_bits(st->regmap,
+						  MAX31827_CONFIGURATION_REG,
+						  MAX31827_CONFIGURATION_1SHOT_MASK |
+						  MAX31827_CONFIGURATION_CNV_RATE_MASK,
+						  MAX31827_DEVICE_ENABLE(val));
 
 		case hwmon_temp_max:
 			return write_alarm_val(st, MAX31827_TH_REG, val);
@@ -329,61 +358,205 @@ static int max31827_write(struct device *dev, enum hwmon_sensor_types type,
 		}
 
 	case hwmon_chip:
-		if (attr == hwmon_chip_update_interval) {
+		switch (attr) {
+		case hwmon_chip_update_interval:
 			if (!st->enable)
 				return -EINVAL;
 
-			switch (val) {
-			case 125:
-				val = MAX31827_CNV_8_HZ;
-				break;
-			case 250:
-				val = MAX31827_CNV_4_HZ;
-				break;
-			case 1000:
-				val = MAX31827_CNV_1_HZ;
-				break;
-			case 4000:
-				val = MAX31827_CNV_1_DIV_4_HZ;
-				break;
-			case 16000:
-				val = MAX31827_CNV_1_DIV_16_HZ;
-				break;
-			case 32000:
-				val = MAX31827_CNV_1_DIV_32_HZ;
-				break;
-			case 64000:
-				val = MAX31827_CNV_1_DIV_64_HZ;
-				break;
-			default:
-				return -EINVAL;
-			}
+			/*
+			 * Convert the desired conversion rate into register
+			 * bits. res is already initialized with 1.
+			 *
+			 * This was inspired by lm73 driver.
+			 */
+			while (res < ARRAY_SIZE(max31827_conversions) &&
+			       val < max31827_conversions[res])
+				res++;
 
-			val = FIELD_PREP(MAX31827_CONFIGURATION_CNV_RATE_MASK,
-					 val);
+			if (res == ARRAY_SIZE(max31827_conversions))
+				res = ARRAY_SIZE(max31827_conversions) - 1;
 
-			return regmap_update_bits(st->regmap,
-						  MAX31827_CONFIGURATION_REG,
-						  MAX31827_CONFIGURATION_CNV_RATE_MASK,
-						  val);
-		}
-		break;
+			res = FIELD_PREP(MAX31827_CONFIGURATION_CNV_RATE_MASK,
+					 res);
+
+			ret = regmap_update_bits(st->regmap,
+						 MAX31827_CONFIGURATION_REG,
+						 MAX31827_CONFIGURATION_CNV_RATE_MASK,
+						 res);
+			if (ret)
+				return ret;
+
+			st->update_interval = val;
 
+			return 0;
+		case hwmon_chip_pec:
+			return regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
+						  MAX31827_CONFIGURATION_PEC_EN_MASK,
+						  val ? MAX31827_CONFIGURATION_PEC_EN_MASK : 0);
+		default:
+			return -EOPNOTSUPP;
+		}
 	default:
 		return -EOPNOTSUPP;
 	}
+}
+
+static ssize_t temp1_resolution_show(struct device *dev,
+				     struct device_attribute *devattr,
+				     char *buf)
+{
+	struct max31827_state *st = dev_get_drvdata(dev);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(st->regmap, MAX31827_CONFIGURATION_REG, &val);
+	if (ret)
+		return ret;
 
-	return -EOPNOTSUPP;
+	val = FIELD_GET(MAX31827_CONFIGURATION_RESOLUTION_MASK, val);
+
+	return sysfs_emit(buf, "%u\n", max31827_resolutions[val]);
 }
 
-static int max31827_init_client(struct max31827_state *st)
+static ssize_t temp1_resolution_store(struct device *dev,
+				      struct device_attribute *devattr,
+				      const char *buf, size_t count)
 {
+	struct max31827_state *st = dev_get_drvdata(dev);
+	unsigned int idx = 0;
+	unsigned int val;
+	int ret;
+
+	ret = kstrtouint(buf, 10, &val);
+	if (ret)
+		return ret;
+
+	/*
+	 * Convert the desired resolution into register
+	 * bits. idx is already initialized with 0.
+	 *
+	 * This was inspired by lm73 driver.
+	 */
+	while (idx < ARRAY_SIZE(max31827_resolutions) &&
+	       val < max31827_resolutions[idx])
+		idx++;
+
+	if (idx == ARRAY_SIZE(max31827_resolutions))
+		idx = ARRAY_SIZE(max31827_resolutions) - 1;
+
+	st->resolution = idx;
+
+	ret = shutdown_write(st, MAX31827_CONFIGURATION_REG,
+			     MAX31827_CONFIGURATION_RESOLUTION_MASK,
+			     FIELD_PREP(MAX31827_CONFIGURATION_RESOLUTION_MASK,
+					idx));
+
+	return ret ? ret : count;
+}
+
+static DEVICE_ATTR_RW(temp1_resolution);
+
+static struct attribute *max31827_attrs[] = {
+	&dev_attr_temp1_resolution.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(max31827);
+
+static const struct i2c_device_id max31827_i2c_ids[] = {
+	{ "max31827", max31827 },
+	{ "max31828", max31828 },
+	{ "max31829", max31829 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max31827_i2c_ids);
+
+static int max31827_init_client(struct max31827_state *st,
+				struct device *dev)
+{
+	struct fwnode_handle *fwnode;
+	unsigned int res = 0;
+	u32 data, lsb_idx;
+	enum chips type;
+	bool prop;
+	int ret;
+
+	fwnode = dev_fwnode(dev);
+
 	st->enable = true;
+	res |= MAX31827_DEVICE_ENABLE(1);
 
-	return regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
-				  MAX31827_CONFIGURATION_1SHOT_MASK |
-					  MAX31827_CONFIGURATION_CNV_RATE_MASK,
-				  MAX31827_DEVICE_ENABLE(1));
+	res |= MAX31827_CONFIGURATION_RESOLUTION_MASK;
+
+	prop = fwnode_property_read_bool(fwnode, "adi,comp-int");
+	res |= FIELD_PREP(MAX31827_CONFIGURATION_COMP_INT_MASK, prop);
+
+	prop = fwnode_property_read_bool(fwnode, "adi,timeout-enable");
+	res |= FIELD_PREP(MAX31827_CONFIGURATION_TIMEOUT_MASK, !prop);
+
+	type = (enum chips)(uintptr_t)device_get_match_data(dev);
+
+	if (fwnode_property_present(fwnode, "adi,alarm-pol")) {
+		ret = fwnode_property_read_u32(fwnode, "adi,alarm-pol", &data);
+		if (ret)
+			return ret;
+
+		res |= FIELD_PREP(MAX31827_CONFIGURATION_ALRM_POL_MASK, !!data);
+	} else {
+		/*
+		 * Set default value.
+		 */
+		switch (type) {
+		case max31827:
+		case max31828:
+			res |= FIELD_PREP(MAX31827_CONFIGURATION_ALRM_POL_MASK,
+					  MAX31827_ALRM_POL_LOW);
+			break;
+		case max31829:
+			res |= FIELD_PREP(MAX31827_CONFIGURATION_ALRM_POL_MASK,
+					  MAX31827_ALRM_POL_HIGH);
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+	}
+
+	if (fwnode_property_present(fwnode, "adi,fault-q")) {
+		ret = fwnode_property_read_u32(fwnode, "adi,fault-q", &data);
+		if (ret)
+			return ret;
+
+		/*
+		 * Convert the desired fault queue into register bits.
+		 */
+		if (data != 0)
+			lsb_idx = __ffs(data);
+
+		if (hweight32(data) != 1 || lsb_idx > 4) {
+			dev_err(dev, "Invalid data in adi,fault-q\n");
+			return -EINVAL;
+		}
+
+		res |= FIELD_PREP(MAX31827_CONFIGURATION_FLT_Q_MASK, lsb_idx);
+	} else {
+		/*
+		 * Set default value.
+		 */
+		switch (type) {
+		case max31827:
+			res |= FIELD_PREP(MAX31827_CONFIGURATION_FLT_Q_MASK,
+					  MAX31827_FLT_Q_1);
+			break;
+		case max31828:
+		case max31829:
+			res |= FIELD_PREP(MAX31827_CONFIGURATION_FLT_Q_MASK,
+					  MAX31827_FLT_Q_4);
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+	}
+
+	return regmap_write(st->regmap, MAX31827_CONFIGURATION_REG, res);
 }
 
 static const struct hwmon_channel_info *max31827_info[] = {
@@ -391,7 +564,7 @@ static const struct hwmon_channel_info *max31827_info[] = {
 					 HWMON_T_MIN_HYST | HWMON_T_MIN_ALARM |
 					 HWMON_T_MAX | HWMON_T_MAX_HYST |
 					 HWMON_T_MAX_ALARM),
-	HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL),
+	HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL | HWMON_C_PEC),
 	NULL,
 };
 
@@ -420,38 +593,44 @@ static int max31827_probe(struct i2c_client *client)
 	if (!st)
 		return -ENOMEM;
 
-	mutex_init(&st->lock);
-
 	st->regmap = devm_regmap_init_i2c(client, &max31827_regmap);
 	if (IS_ERR(st->regmap))
 		return dev_err_probe(dev, PTR_ERR(st->regmap),
 				     "Failed to allocate regmap.\n");
 
-	err = max31827_init_client(st);
+	err = devm_regulator_get_enable(dev, "vref");
+	if (err)
+		return dev_err_probe(dev, err, "failed to enable regulator\n");
+
+	err = max31827_init_client(st, dev);
 	if (err)
 		return err;
 
 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, st,
 							 &max31827_chip_info,
-							 NULL);
+							 max31827_groups);
 
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }
 
-static const struct i2c_device_id max31827_i2c_ids[] = {
-	{ "max31827", 0 },
-	{ }
-};
-MODULE_DEVICE_TABLE(i2c, max31827_i2c_ids);
-
 static const struct of_device_id max31827_of_match[] = {
-	{ .compatible = "adi,max31827" },
+	{
+		.compatible = "adi,max31827",
+		.data = (void *)max31827
+	},
+	{
+		.compatible = "adi,max31828",
+		.data = (void *)max31828
+	},
+	{
+		.compatible = "adi,max31829",
+		.data = (void *)max31829
+	},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, max31827_of_match);
 
 static struct i2c_driver max31827_driver = {
-	.class = I2C_CLASS_HWMON,
 	.driver = {
 		.name = "max31827",
 		.of_match_table = max31827_of_match,