[PATCH 1/8] hwmon: (lm83) Cleanup, conversion to regmap and with_info API order

[PATCH 1/8] hwmon: (lm83) Cleanup, conversion to regmap and with_info API order

[Guenter Roeck]

Clean up driver code, use regmap and with_info API to improve readability
and reduce code size.

----------------------------------------------------------------
Guenter Roeck (8):
      hwmon: (lm83) Reorder include files to be in alphabetic order
      hwmon: (lm83) Move lm83_id to avoid forward declaration
      hwmon: (lm83) Replace new_client with client
      hwmon: (lm83) Use regmap
      hwmon: (lm83) Replace temperature conversion macros with standard functions
      hwmon: (lm83) Demote log message if chip identification fails
      hwmon: (lm83) Explain why LM82 may be misdetected as LM83
      hwmon: (lm83) Convert to use with_info API

 drivers/hwmon/lm83.c | 476 ++++++++++++++++++++++++++++++---------------------
 1 file changed, 284 insertions(+), 192 deletions(-)

[PATCH 1/8] hwmon: (lm83) Reorder include files to be in alphabetic order

[Guenter Roeck]

Reorder include files to be in alphabetic order to simplify
driver maintenance.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lm83.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/hwmon/lm83.c b/drivers/hwmon/lm83.c
index 74fd7aa373a3..44d720af2473 100644
--- a/drivers/hwmon/lm83.c
+++ b/drivers/hwmon/lm83.c
@@ -18,15 +18,15 @@
  * http://www.national.com/pf/LM/LM82.html
  */
 
-#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
 #include <linux/init.h>
-#include <linux/slab.h>
 #include <linux/jiffies.h>
-#include <linux/i2c.h>
-#include <linux/hwmon-sysfs.h>
 #include <linux/hwmon.h>
-#include <linux/err.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/slab.h>
 #include <linux/sysfs.h>
 
 /*
-- 
2.33.0

[PATCH 2/8] hwmon: (lm83) Move lm83_id to avoid forward declaration

[Guenter Roeck]

There is no need to keep lm83_id at the end of the driver. Move it
forward to where it is needed to avoid a forward declaration.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lm83.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/hwmon/lm83.c b/drivers/hwmon/lm83.c
index 44d720af2473..2bb4bceef551 100644
--- a/drivers/hwmon/lm83.c
+++ b/drivers/hwmon/lm83.c
@@ -317,7 +317,12 @@ static int lm83_detect(struct i2c_client *new_client,
 	return 0;
 }
 
-static const struct i2c_device_id lm83_id[];
+static const struct i2c_device_id lm83_id[] = {
+	{ "lm83", lm83 },
+	{ "lm82", lm82 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, lm83_id);
 
 static int lm83_probe(struct i2c_client *new_client)
 {
@@ -352,13 +357,6 @@ static int lm83_probe(struct i2c_client *new_client)
  * Driver data (common to all clients)
  */
 
-static const struct i2c_device_id lm83_id[] = {
-	{ "lm83", lm83 },
-	{ "lm82", lm82 },
-	{ }
-};
-MODULE_DEVICE_TABLE(i2c, lm83_id);
-
 static struct i2c_driver lm83_driver = {
 	.class		= I2C_CLASS_HWMON,
 	.driver = {
-- 
2.33.0

[PATCH 3/8] hwmon: (lm83) Replace new_client with client

[Guenter Roeck]

It has no value to name a variable 'new_client' in probe and detect
functions; it is obvious that the client is new. Use 'client' as
variable name instead.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lm83.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/hwmon/lm83.c b/drivers/hwmon/lm83.c
index 2bb4bceef551..fdd89cc481fa 100644
--- a/drivers/hwmon/lm83.c
+++ b/drivers/hwmon/lm83.c
@@ -272,10 +272,10 @@ static const struct attribute_group lm83_group_opt = {
  */
 
 /* Return 0 if detection is successful, -ENODEV otherwise */
-static int lm83_detect(struct i2c_client *new_client,
+static int lm83_detect(struct i2c_client *client,
 		       struct i2c_board_info *info)
 {
-	struct i2c_adapter *adapter = new_client->adapter;
+	struct i2c_adapter *adapter = client->adapter;
 	const char *name;
 	u8 man_id, chip_id;
 
@@ -283,20 +283,20 @@ static int lm83_detect(struct i2c_client *new_client,
 		return -ENODEV;
 
 	/* Detection */
-	if ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1) & 0xA8) ||
-	    (i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2) & 0x48) ||
-	    (i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG) & 0x41)) {
+	if ((i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1) & 0xA8) ||
+	    (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2) & 0x48) ||
+	    (i2c_smbus_read_byte_data(client, LM83_REG_R_CONFIG) & 0x41)) {
 		dev_dbg(&adapter->dev, "LM83 detection failed at 0x%02x\n",
-			new_client->addr);
+			client->addr);
 		return -ENODEV;
 	}
 
 	/* Identification */
-	man_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_MAN_ID);
+	man_id = i2c_smbus_read_byte_data(client, LM83_REG_R_MAN_ID);
 	if (man_id != 0x01)	/* National Semiconductor */
 		return -ENODEV;
 
-	chip_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_CHIP_ID);
+	chip_id = i2c_smbus_read_byte_data(client, LM83_REG_R_CHIP_ID);
 	switch (chip_id) {
 	case 0x03:
 		name = "lm83";
@@ -324,17 +324,17 @@ static const struct i2c_device_id lm83_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, lm83_id);
 
-static int lm83_probe(struct i2c_client *new_client)
+static int lm83_probe(struct i2c_client *client)
 {
 	struct device *hwmon_dev;
 	struct lm83_data *data;
 
-	data = devm_kzalloc(&new_client->dev, sizeof(struct lm83_data),
+	data = devm_kzalloc(&client->dev, sizeof(struct lm83_data),
 			    GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
 
-	data->client = new_client;
+	data->client = client;
 	mutex_init(&data->update_lock);
 
 	/*
@@ -344,11 +344,11 @@ static int lm83_probe(struct i2c_client *new_client)
 	 * declare 1 and 3 common, and then 2 and 4 only for the LM83.
 	 */
 	data->groups[0] = &lm83_group;
-	if (i2c_match_id(lm83_id, new_client)->driver_data == lm83)
+	if (i2c_match_id(lm83_id, client)->driver_data == lm83)
 		data->groups[1] = &lm83_group_opt;
 
-	hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
-							   new_client->name,
+	hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
+							   client->name,
 							   data, data->groups);
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }
-- 
2.33.0

[PATCH 4/8] hwmon: (lm83) Use regmap

[Guenter Roeck]

Using local caching in this driver had few benefits. It used cached values
for two seconds and then re-read all registers from the chip even if the
user only accessed a single attribute. On top of that, alarm attributes
were stale for up to four seconds (the first status register read reports
and clears an alarm, the second reports it cleared). Use regmap instead
for caching. Do not re-read non-volatile registers, and do not cache
volatile registers.

As part of this change, handle register read and write address differences
in regmap code. This is necessary to avoid problems with caching in the
regmap core, and ultimately simplifies the code.

Also, errors observed when reading from and writing to registers are no
longer ignored.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lm83.c | 176 +++++++++++++++++++++++++++----------------
 1 file changed, 111 insertions(+), 65 deletions(-)

diff --git a/drivers/hwmon/lm83.c b/drivers/hwmon/lm83.c
index fdd89cc481fa..c9605957e400 100644
--- a/drivers/hwmon/lm83.c
+++ b/drivers/hwmon/lm83.c
@@ -21,11 +21,11 @@
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
-#include <linux/jiffies.h>
 #include <linux/hwmon.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 
@@ -77,7 +77,7 @@ enum chips { lm83, lm82 };
 				 (val) < 0 ? ((val) - 500) / 1000 : \
 				 ((val) + 500) / 1000)
 
-static const u8 LM83_REG_R_TEMP[] = {
+static const u8 LM83_REG_TEMP[] = {
 	LM83_REG_R_LOCAL_TEMP,
 	LM83_REG_R_REMOTE1_TEMP,
 	LM83_REG_R_REMOTE2_TEMP,
@@ -89,62 +89,82 @@ static const u8 LM83_REG_R_TEMP[] = {
 	LM83_REG_R_TCRIT,
 };
 
-static const u8 LM83_REG_W_HIGH[] = {
-	LM83_REG_W_LOCAL_HIGH,
-	LM83_REG_W_REMOTE1_HIGH,
-	LM83_REG_W_REMOTE2_HIGH,
-	LM83_REG_W_REMOTE3_HIGH,
-	LM83_REG_W_TCRIT,
-};
-
 /*
  * Client data (each client gets its own)
  */
 
 struct lm83_data {
-	struct i2c_client *client;
+	struct regmap *regmap;
 	const struct attribute_group *groups[3];
-	struct mutex update_lock;
-	bool valid; /* false until following fields are valid */
-	unsigned long last_updated; /* in jiffies */
-
-	/* registers values */
-	s8 temp[9];	/* 0..3: input 1-4,
-			   4..7: high limit 1-4,
-			   8   : critical limit */
-	u16 alarms; /* bitvector, combined */
 };
 
-static struct lm83_data *lm83_update_device(struct device *dev)
+/* regmap code */
+
+static int lm83_regmap_reg_read(void *context, unsigned int reg, unsigned int *val)
 {
-	struct lm83_data *data = dev_get_drvdata(dev);
-	struct i2c_client *client = data->client;
-
-	mutex_lock(&data->update_lock);
-
-	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
-		int nr;
-
-		dev_dbg(&client->dev, "Updating lm83 data.\n");
-		for (nr = 0; nr < 9; nr++) {
-			data->temp[nr] =
-			    i2c_smbus_read_byte_data(client,
-			    LM83_REG_R_TEMP[nr]);
-		}
-		data->alarms =
-		    i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
-		    + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
-		    << 8);
-
-		data->last_updated = jiffies;
-		data->valid = true;
+	struct i2c_client *client = context;
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(client, reg);
+	if (ret < 0)
+		return ret;
+
+	*val = ret;
+	return 0;
+}
+
+/*
+ * The regmap write function maps read register addresses to write register
+ * addresses. This is necessary for regmap register caching to work.
+ * An alternative would be to clear the regmap cache whenever a register is
+ * written, but that would be much more expensive.
+ */
+static int lm83_regmap_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct i2c_client *client = context;
+
+	switch (reg) {
+	case LM83_REG_R_CONFIG:
+	case LM83_REG_R_LOCAL_HIGH:
+	case LM83_REG_R_REMOTE2_HIGH:
+		reg += 0x06;
+		break;
+	case LM83_REG_R_REMOTE1_HIGH:
+	case LM83_REG_R_REMOTE3_HIGH:
+	case LM83_REG_R_TCRIT:
+		reg += 0x18;
+		break;
+	default:
+		break;
 	}
 
-	mutex_unlock(&data->update_lock);
+	return i2c_smbus_write_byte_data(client, reg, val);
+}
 
-	return data;
+static bool lm83_regmap_is_volatile(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case LM83_REG_R_LOCAL_TEMP:
+	case LM83_REG_R_REMOTE1_TEMP:
+	case LM83_REG_R_REMOTE2_TEMP:
+	case LM83_REG_R_REMOTE3_TEMP:
+	case LM83_REG_R_STATUS1:
+	case LM83_REG_R_STATUS2:
+		return true;
+	default:
+		return false;
+	}
 }
 
+static const struct regmap_config lm83_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.cache_type = REGCACHE_RBTREE,
+	.volatile_reg = lm83_regmap_is_volatile,
+	.reg_read = lm83_regmap_reg_read,
+	.reg_write = lm83_regmap_reg_write,
+};
+
 /*
  * Sysfs stuff
  */
@@ -153,8 +173,15 @@ static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
 			 char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
-	struct lm83_data *data = lm83_update_device(dev);
-	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
+	struct lm83_data *data = dev_get_drvdata(dev);
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(data->regmap, LM83_REG_TEMP[attr->index], &regval);
+	if (ret)
+		return ret;
+
+	return sprintf(buf, "%d\n", TEMP_FROM_REG((s8)regval));
 }
 
 static ssize_t temp_store(struct device *dev,
@@ -163,38 +190,57 @@ static ssize_t temp_store(struct device *dev,
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 	struct lm83_data *data = dev_get_drvdata(dev);
-	struct i2c_client *client = data->client;
+	unsigned int regval;
 	long val;
-	int nr = attr->index;
 	int err;
 
 	err = kstrtol(buf, 10, &val);
 	if (err < 0)
 		return err;
 
-	mutex_lock(&data->update_lock);
-	data->temp[nr] = TEMP_TO_REG(val);
-	i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
-				  data->temp[nr]);
-	mutex_unlock(&data->update_lock);
-	return count;
+	regval = TEMP_TO_REG(val);
+	err = regmap_write(data->regmap, LM83_REG_TEMP[attr->index], regval);
+	return err ? : count;
 }
 
 static ssize_t alarms_show(struct device *dev, struct device_attribute *dummy,
 			   char *buf)
 {
-	struct lm83_data *data = lm83_update_device(dev);
-	return sprintf(buf, "%d\n", data->alarms);
+	struct lm83_data *data = dev_get_drvdata(dev);
+	unsigned int alarms, regval;
+	int err;
+
+	err = regmap_read(data->regmap, LM83_REG_R_STATUS1, &regval);
+	if (err < 0)
+		return err;
+	alarms = regval;
+	err = regmap_read(data->regmap, LM83_REG_R_STATUS2, &regval);
+	if (err < 0)
+		return err;
+	alarms |= regval << 8;
+
+	return sprintf(buf, "%u\n", alarms);
 }
 
 static ssize_t alarm_show(struct device *dev,
 			  struct device_attribute *devattr, char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
-	struct lm83_data *data = lm83_update_device(dev);
+	struct lm83_data *data = dev_get_drvdata(dev);
 	int bitnr = attr->index;
-
-	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
+	unsigned int alarm;
+	int reg, err;
+
+	if (bitnr < 8) {
+		reg = LM83_REG_R_STATUS1;
+	} else {
+		reg = LM83_REG_R_STATUS2;
+		bitnr -= 8;
+	}
+	err = regmap_read(data->regmap, reg, &alarm);
+	if (err < 0)
+		return err;
+	return sprintf(buf, "%d\n", (alarm >> bitnr) & 1);
 }
 
 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
@@ -326,16 +372,17 @@ MODULE_DEVICE_TABLE(i2c, lm83_id);
 
 static int lm83_probe(struct i2c_client *client)
 {
+	struct device *dev = &client->dev;
 	struct device *hwmon_dev;
 	struct lm83_data *data;
 
-	data = devm_kzalloc(&client->dev, sizeof(struct lm83_data),
-			    GFP_KERNEL);
+	data = devm_kzalloc(dev, sizeof(struct lm83_data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
 
-	data->client = client;
-	mutex_init(&data->update_lock);
+	data->regmap = devm_regmap_init(dev, NULL, client, &lm83_regmap_config);
+	if (IS_ERR(data->regmap))
+		return PTR_ERR(data->regmap);
 
 	/*
 	 * Register sysfs hooks
@@ -347,8 +394,7 @@ static int lm83_probe(struct i2c_client *client)
 	if (i2c_match_id(lm83_id, client)->driver_data == lm83)
 		data->groups[1] = &lm83_group_opt;
 
-	hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
-							   client->name,
+	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 							   data, data->groups);
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }
-- 
2.33.0

[PATCH 5/8] hwmon: (lm83) Replace temperature conversion macros with standard functions

[Guenter Roeck]

Replace TEMP_FROM_REG with direct calculation and TEMP_TO_REG
with standard functions/macros.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lm83.c | 15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

diff --git a/drivers/hwmon/lm83.c b/drivers/hwmon/lm83.c
index c9605957e400..434bd5b903d2 100644
--- a/drivers/hwmon/lm83.c
+++ b/drivers/hwmon/lm83.c
@@ -66,17 +66,6 @@ enum chips { lm83, lm82 };
 #define LM83_REG_R_TCRIT		0x42
 #define LM83_REG_W_TCRIT		0x5A
 
-/*
- * Conversions and various macros
- * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
- */
-
-#define TEMP_FROM_REG(val)	((val) * 1000)
-#define TEMP_TO_REG(val)	((val) <= -128000 ? -128 : \
-				 (val) >= 127000 ? 127 : \
-				 (val) < 0 ? ((val) - 500) / 1000 : \
-				 ((val) + 500) / 1000)
-
 static const u8 LM83_REG_TEMP[] = {
 	LM83_REG_R_LOCAL_TEMP,
 	LM83_REG_R_REMOTE1_TEMP,
@@ -181,7 +170,7 @@ static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
 	if (ret)
 		return ret;
 
-	return sprintf(buf, "%d\n", TEMP_FROM_REG((s8)regval));
+	return sprintf(buf, "%d\n", (s8)regval * 1000);
 }
 
 static ssize_t temp_store(struct device *dev,
@@ -198,7 +187,7 @@ static ssize_t temp_store(struct device *dev,
 	if (err < 0)
 		return err;
 
-	regval = TEMP_TO_REG(val);
+	regval = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);
 	err = regmap_write(data->regmap, LM83_REG_TEMP[attr->index], regval);
 	return err ? : count;
 }
-- 
2.33.0

[PATCH 6/8] hwmon: (lm83) Demote log message if chip identification fails

[Guenter Roeck]

There should be no message in the kernel function if the detect function
fails to identify a chip; this is perfectly normal and does not warrant
a kernel log entry. Demote message to debug.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lm83.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hwmon/lm83.c b/drivers/hwmon/lm83.c
index 434bd5b903d2..82d7ef264f6f 100644
--- a/drivers/hwmon/lm83.c
+++ b/drivers/hwmon/lm83.c
@@ -341,9 +341,9 @@ static int lm83_detect(struct i2c_client *client,
 		break;
 	default:
 		/* identification failed */
-		dev_info(&adapter->dev,
-			 "Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
-			 man_id, chip_id);
+		dev_dbg(&adapter->dev,
+			"Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
+			man_id, chip_id);
 		return -ENODEV;
 	}
 
-- 
2.33.0

[PATCH 7/8] hwmon: (lm83) Explain why LM82 may be misdetected as LM83

[Guenter Roeck]

According to the March 2013 revision of the LM82 datasheet, the latest
LM82 die revision is 0x03. This was confirmed and observed with a real
chip. Further details in this revision of the LM82 datasheet suggest that
LM82 is now just a repackaged LM83. Such versions of LM82 will be detected
as LM83. Add comment to the code explaining why this may happen.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lm83.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/hwmon/lm83.c b/drivers/hwmon/lm83.c
index 82d7ef264f6f..d9ee01ca8aed 100644
--- a/drivers/hwmon/lm83.c
+++ b/drivers/hwmon/lm83.c
@@ -334,6 +334,14 @@ static int lm83_detect(struct i2c_client *client,
 	chip_id = i2c_smbus_read_byte_data(client, LM83_REG_R_CHIP_ID);
 	switch (chip_id) {
 	case 0x03:
+		/*
+		 * According to the LM82 datasheet dated March 2013, recent
+		 * revisions of LM82 have a die revision of 0x03. This was
+		 * confirmed with a real chip. Further details in this revision
+		 * of the LM82 datasheet strongly suggest that LM82 is just a
+		 * repackaged LM83. It is therefore impossible to distinguish
+		 * those chips from LM83, and they will be misdetected as LM83.
+		 */
 		name = "lm83";
 		break;
 	case 0x01:
-- 
2.33.0

[PATCH 8/8] hwmon: (lm83) Convert to use with_info API

[Guenter Roeck]

Use with_info API to reduce code size and simplify the code.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lm83.c | 315 +++++++++++++++++++++++++------------------
 1 file changed, 183 insertions(+), 132 deletions(-)

diff --git a/drivers/hwmon/lm83.c b/drivers/hwmon/lm83.c
index d9ee01ca8aed..7047de234ee1 100644
--- a/drivers/hwmon/lm83.c
+++ b/drivers/hwmon/lm83.c
@@ -18,11 +18,11 @@
  * http://www.national.com/pf/LM/LM82.html
  */
 
+#include <linux/bits.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/hwmon.h>
-#include <linux/hwmon-sysfs.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/regmap.h>
@@ -71,11 +71,30 @@ static const u8 LM83_REG_TEMP[] = {
 	LM83_REG_R_REMOTE1_TEMP,
 	LM83_REG_R_REMOTE2_TEMP,
 	LM83_REG_R_REMOTE3_TEMP,
+};
+
+static const u8 LM83_REG_MAX[] = {
 	LM83_REG_R_LOCAL_HIGH,
 	LM83_REG_R_REMOTE1_HIGH,
 	LM83_REG_R_REMOTE2_HIGH,
 	LM83_REG_R_REMOTE3_HIGH,
-	LM83_REG_R_TCRIT,
+};
+
+/* alarm and fault registers and bits, indexed by channel */
+static const u8 LM83_ALARM_REG[] = {
+	LM83_REG_R_STATUS1, LM83_REG_R_STATUS2, LM83_REG_R_STATUS1, LM83_REG_R_STATUS2
+};
+
+static const u8 LM83_MAX_ALARM_BIT[] = {
+	BIT(6), BIT(7), BIT(4), BIT(4)
+};
+
+static const u8 LM83_CRIT_ALARM_BIT[] = {
+	BIT(0), BIT(0), BIT(1), BIT(1)
+};
+
+static const u8 LM83_FAULT_BIT[] = {
+	0, BIT(5), BIT(2), BIT(2)
 };
 
 /*
@@ -84,7 +103,7 @@ static const u8 LM83_REG_TEMP[] = {
 
 struct lm83_data {
 	struct regmap *regmap;
-	const struct attribute_group *groups[3];
+	enum chips type;
 };
 
 /* regmap code */
@@ -154,157 +173,197 @@ static const struct regmap_config lm83_regmap_config = {
 	.reg_write = lm83_regmap_reg_write,
 };
 
-/*
- * Sysfs stuff
- */
+/* hwmon API */
 
-static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
-			 char *buf)
+static int lm83_temp_read(struct device *dev, u32 attr, int channel, long *val)
 {
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 	struct lm83_data *data = dev_get_drvdata(dev);
 	unsigned int regval;
-	int ret;
-
-	ret = regmap_read(data->regmap, LM83_REG_TEMP[attr->index], &regval);
-	if (ret)
-		return ret;
+	int err;
 
-	return sprintf(buf, "%d\n", (s8)regval * 1000);
+	switch (attr) {
+	case hwmon_temp_input:
+		err = regmap_read(data->regmap, LM83_REG_TEMP[channel], &regval);
+		if (err < 0)
+			return err;
+		*val = (s8)regval * 1000;
+		break;
+	case hwmon_temp_max:
+		err = regmap_read(data->regmap, LM83_REG_MAX[channel], &regval);
+		if (err < 0)
+			return err;
+		*val = (s8)regval * 1000;
+		break;
+	case hwmon_temp_crit:
+		err = regmap_read(data->regmap, LM83_REG_R_TCRIT, &regval);
+		if (err < 0)
+			return err;
+		*val = (s8)regval * 1000;
+		break;
+	case hwmon_temp_max_alarm:
+		err = regmap_read(data->regmap, LM83_ALARM_REG[channel], &regval);
+		if (err < 0)
+			return err;
+		*val = !!(regval & LM83_MAX_ALARM_BIT[channel]);
+		break;
+	case hwmon_temp_crit_alarm:
+		err = regmap_read(data->regmap, LM83_ALARM_REG[channel], &regval);
+		if (err < 0)
+			return err;
+		*val = !!(regval & LM83_CRIT_ALARM_BIT[channel]);
+		break;
+	case hwmon_temp_fault:
+		err = regmap_read(data->regmap, LM83_ALARM_REG[channel], &regval);
+		if (err < 0)
+			return err;
+		*val = !!(regval & LM83_FAULT_BIT[channel]);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
 }
 
-static ssize_t temp_store(struct device *dev,
-			  struct device_attribute *devattr, const char *buf,
-			  size_t count)
+static int lm83_temp_write(struct device *dev, u32 attr, int channel, long val)
 {
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 	struct lm83_data *data = dev_get_drvdata(dev);
 	unsigned int regval;
-	long val;
 	int err;
 
-	err = kstrtol(buf, 10, &val);
-	if (err < 0)
-		return err;
-
 	regval = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);
-	err = regmap_write(data->regmap, LM83_REG_TEMP[attr->index], regval);
-	return err ? : count;
+
+	switch (attr) {
+	case hwmon_temp_max:
+		err = regmap_write(data->regmap, LM83_REG_MAX[channel], regval);
+		if (err < 0)
+			return err;
+		break;
+	case hwmon_temp_crit:
+		err = regmap_write(data->regmap, LM83_REG_R_TCRIT, regval);
+		if (err < 0)
+			return err;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
 }
 
-static ssize_t alarms_show(struct device *dev, struct device_attribute *dummy,
-			   char *buf)
+static int lm83_chip_read(struct device *dev, u32 attr, int channel, long *val)
 {
 	struct lm83_data *data = dev_get_drvdata(dev);
-	unsigned int alarms, regval;
+	unsigned int regval;
 	int err;
 
-	err = regmap_read(data->regmap, LM83_REG_R_STATUS1, &regval);
-	if (err < 0)
-		return err;
-	alarms = regval;
-	err = regmap_read(data->regmap, LM83_REG_R_STATUS2, &regval);
-	if (err < 0)
-		return err;
-	alarms |= regval << 8;
+	switch (attr) {
+	case hwmon_chip_alarms:
+		err = regmap_read(data->regmap, LM83_REG_R_STATUS1, &regval);
+		if (err < 0)
+			return err;
+		*val = regval;
+		err = regmap_read(data->regmap, LM83_REG_R_STATUS2, &regval);
+		if (err < 0)
+			return err;
+		*val |= regval << 8;
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
 
-	return sprintf(buf, "%u\n", alarms);
+	return 0;
 }
 
-static ssize_t alarm_show(struct device *dev,
-			  struct device_attribute *devattr, char *buf)
+static int lm83_read(struct device *dev, enum hwmon_sensor_types type,
+		     u32 attr, int channel, long *val)
 {
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
-	struct lm83_data *data = dev_get_drvdata(dev);
-	int bitnr = attr->index;
-	unsigned int alarm;
-	int reg, err;
-
-	if (bitnr < 8) {
-		reg = LM83_REG_R_STATUS1;
-	} else {
-		reg = LM83_REG_R_STATUS2;
-		bitnr -= 8;
+	switch (type) {
+	case hwmon_chip:
+		return lm83_chip_read(dev, attr, channel, val);
+	case hwmon_temp:
+		return lm83_temp_read(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
 	}
-	err = regmap_read(data->regmap, reg, &alarm);
-	if (err < 0)
-		return err;
-	return sprintf(buf, "%d\n", (alarm >> bitnr) & 1);
 }
 
-static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
-static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, 1);
-static SENSOR_DEVICE_ATTR_RO(temp3_input, temp, 2);
-static SENSOR_DEVICE_ATTR_RO(temp4_input, temp, 3);
-static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 4);
-static SENSOR_DEVICE_ATTR_RW(temp2_max, temp, 5);
-static SENSOR_DEVICE_ATTR_RW(temp3_max, temp, 6);
-static SENSOR_DEVICE_ATTR_RW(temp4_max, temp, 7);
-static SENSOR_DEVICE_ATTR_RO(temp1_crit, temp, 8);
-static SENSOR_DEVICE_ATTR_RO(temp2_crit, temp, 8);
-static SENSOR_DEVICE_ATTR_RW(temp3_crit, temp, 8);
-static SENSOR_DEVICE_ATTR_RO(temp4_crit, temp, 8);
-
-/* Individual alarm files */
-static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 0);
-static SENSOR_DEVICE_ATTR_RO(temp3_crit_alarm, alarm, 1);
-static SENSOR_DEVICE_ATTR_RO(temp3_fault, alarm, 2);
-static SENSOR_DEVICE_ATTR_RO(temp3_max_alarm, alarm, 4);
-static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 6);
-static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 8);
-static SENSOR_DEVICE_ATTR_RO(temp4_crit_alarm, alarm, 9);
-static SENSOR_DEVICE_ATTR_RO(temp4_fault, alarm, 10);
-static SENSOR_DEVICE_ATTR_RO(temp4_max_alarm, alarm, 12);
-static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 13);
-static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 15);
-/* Raw alarm file for compatibility */
-static DEVICE_ATTR_RO(alarms);
-
-static struct attribute *lm83_attributes[] = {
-	&sensor_dev_attr_temp1_input.dev_attr.attr,
-	&sensor_dev_attr_temp3_input.dev_attr.attr,
-	&sensor_dev_attr_temp1_max.dev_attr.attr,
-	&sensor_dev_attr_temp3_max.dev_attr.attr,
-	&sensor_dev_attr_temp1_crit.dev_attr.attr,
-	&sensor_dev_attr_temp3_crit.dev_attr.attr,
-
-	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
-	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
-	&sensor_dev_attr_temp3_fault.dev_attr.attr,
-	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
-	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
-	&dev_attr_alarms.attr,
-	NULL
-};
+static int lm83_write(struct device *dev, enum hwmon_sensor_types type,
+		      u32 attr, int channel, long val)
+{
+	switch (type) {
+	case hwmon_temp:
+		return lm83_temp_write(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
 
-static const struct attribute_group lm83_group = {
-	.attrs = lm83_attributes,
-};
+static umode_t lm83_is_visible(const void *_data, enum hwmon_sensor_types type,
+			       u32 attr, int channel)
+{
+	const struct lm83_data *data = _data;
 
-static struct attribute *lm83_attributes_opt[] = {
-	&sensor_dev_attr_temp2_input.dev_attr.attr,
-	&sensor_dev_attr_temp4_input.dev_attr.attr,
-	&sensor_dev_attr_temp2_max.dev_attr.attr,
-	&sensor_dev_attr_temp4_max.dev_attr.attr,
-	&sensor_dev_attr_temp2_crit.dev_attr.attr,
-	&sensor_dev_attr_temp4_crit.dev_attr.attr,
-
-	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
-	&sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
-	&sensor_dev_attr_temp4_fault.dev_attr.attr,
-	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
-	&sensor_dev_attr_temp2_fault.dev_attr.attr,
-	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
+	/*
+	 * LM82 only supports a single external channel, modeled as channel 2.
+	 */
+	if (data->type == lm82 && (channel == 1 || channel == 3))
+		return 0;
+
+	switch (type) {
+	case hwmon_chip:
+		if (attr == hwmon_chip_alarms)
+			return 0444;
+		break;
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_input:
+		case hwmon_temp_max_alarm:
+		case hwmon_temp_crit_alarm:
+			return 0444;
+		case hwmon_temp_fault:
+			if (channel)
+				return 0444;
+			break;
+		case hwmon_temp_max:
+			return 0644;
+		case hwmon_temp_crit:
+			if (channel == 2)
+				return 0644;
+			return 0444;
+		default:
+			break;
+		}
+		break;
+	default:
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static const struct hwmon_channel_info *lm83_info[] = {
+	HWMON_CHANNEL_INFO(chip, HWMON_C_ALARMS),
+	HWMON_CHANNEL_INFO(temp,
+			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM,
+			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
+			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
+			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT
+			   ),
 	NULL
 };
 
-static const struct attribute_group lm83_group_opt = {
-	.attrs = lm83_attributes_opt,
+static const struct hwmon_ops lm83_hwmon_ops = {
+	.is_visible = lm83_is_visible,
+	.read = lm83_read,
+	.write = lm83_write,
 };
 
-/*
- * Real code
- */
+static const struct hwmon_chip_info lm83_chip_info = {
+	.ops = &lm83_hwmon_ops,
+	.info = lm83_info,
+};
 
 /* Return 0 if detection is successful, -ENODEV otherwise */
 static int lm83_detect(struct i2c_client *client,
@@ -381,18 +440,10 @@ static int lm83_probe(struct i2c_client *client)
 	if (IS_ERR(data->regmap))
 		return PTR_ERR(data->regmap);
 
-	/*
-	 * Register sysfs hooks
-	 * The LM82 can only monitor one external diode which is
-	 * at the same register as the LM83 temp3 entry - so we
-	 * declare 1 and 3 common, and then 2 and 4 only for the LM83.
-	 */
-	data->groups[0] = &lm83_group;
-	if (i2c_match_id(lm83_id, client)->driver_data == lm83)
-		data->groups[1] = &lm83_group_opt;
+	data->type = i2c_match_id(lm83_id, client)->driver_data;
 
-	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
-							   data, data->groups);
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
+							 data, &lm83_chip_info, NULL);
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }
 
-- 
2.33.0