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Commit 28a340db authored by Guenter Roeck's avatar Guenter Roeck
Browse files

hwmon: (tmp102) Convert to use regmap, and drop local cache 



By converting the driver to regmap, we can use regmap to cache non-volatile
registers. Stop caching the temperature register; while potentially reading
it more often can result in reading it more often than necessary, this is
offset by the gain due to not re-reading the limit registers.

A positive side effect of this change is that limit registers can now be
read and updated before the first temperature conversion is complete.

Acked-by: default avatarNishanth Menon <nm@ti.com>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent a9f92ccf

drivers/hwmon/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -1561,6 +1561,7 @@ config SENSORS_TMP102 
	tristate "Texas Instruments TMP102"

	depends on I2C

	depends on THERMAL || !THERMAL_OF

	select REGMAP_I2C

	help

	  If you say yes here you get support for Texas Instruments TMP102

	  sensor chips.

drivers/hwmon/tmp102.c

+70 −78
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/mutex.h>

#include <linux/device.h>

#include <linux/jiffies.h>

#include <linux/regmap.h>

#include <linux/thermal.h>

#include <linux/of.h>
@@ -61,13 +62,9 @@ 
#define CONVERSION_TIME_MS		35	/* in milli-seconds */



struct tmp102 {

	struct i2c_client *client;

	struct mutex lock;

	struct regmap *regmap;

	u16 config_orig;

	unsigned long last_update;

	unsigned long ready_time;

	bool valid;

	int temp[3];

};



/* convert left adjusted 13-bit TMP102 register value to milliCelsius */
@@ -82,45 +79,22 @@ static inline u16 tmp102_mC_to_reg(int val) 
	return (val * 128) / 1000;

}



static const u8 tmp102_reg[] = {

	TMP102_TEMP_REG,

	TMP102_TLOW_REG,

	TMP102_THIGH_REG,

};



static void tmp102_update_device(struct device *dev)

{

	struct tmp102 *tmp102 = dev_get_drvdata(dev);

	struct i2c_client *client = tmp102->client;



	mutex_lock(&tmp102->lock);

	if (!tmp102->valid ||

	    time_after(jiffies, tmp102->last_update + HZ / 3)) {

		int i;

		for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {

			int status = i2c_smbus_read_word_swapped(client,

								 tmp102_reg[i]);

			if (status > -1)

				tmp102->temp[i] = tmp102_reg_to_mC(status);

		}

		tmp102->last_update = jiffies;

		tmp102->valid = true;

	}

	mutex_unlock(&tmp102->lock);

}



static int tmp102_read_temp(void *dev, int *temp)

{

	struct tmp102 *tmp102 = dev_get_drvdata(dev);

	unsigned int reg;

	int ret;



	if (time_before(jiffies, tmp102->ready_time)) {

		dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);

		return -EAGAIN;

	}



	tmp102_update_device(dev);

	ret = regmap_read(tmp102->regmap, TMP102_TEMP_REG, &reg);

	if (ret < 0)

		return ret;



	*temp = tmp102->temp[0];

	*temp = tmp102_reg_to_mC(reg);



	return 0;

}
@@ -131,13 +105,19 @@ static ssize_t tmp102_show_temp(struct device *dev, 
{

	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);

	struct tmp102 *tmp102 = dev_get_drvdata(dev);

	int regaddr = sda->index;

	unsigned int reg;

	int err;



	if (time_before(jiffies, tmp102->ready_time))

	if (regaddr == TMP102_TEMP_REG &&

	    time_before(jiffies, tmp102->ready_time))

		return -EAGAIN;



	tmp102_update_device(dev);

	err = regmap_read(tmp102->regmap, regaddr, &reg);

	if (err < 0)

		return err;



	return sprintf(buf, "%d\n", tmp102->temp[sda->index]);

	return sprintf(buf, "%d\n", tmp102_reg_to_mC(reg));

}



static ssize_t tmp102_set_temp(struct device *dev,
@@ -146,29 +126,26 @@ static ssize_t tmp102_set_temp(struct device *dev, 
{

	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);

	struct tmp102 *tmp102 = dev_get_drvdata(dev);

	struct i2c_client *client = tmp102->client;

	int reg = sda->index;

	long val;

	int status;

	int err;



	if (kstrtol(buf, 10, &val) < 0)

		return -EINVAL;

	val = clamp_val(val, -256000, 255000);



	mutex_lock(&tmp102->lock);

	tmp102->temp[sda->index] = val;

	status = i2c_smbus_write_word_swapped(client, tmp102_reg[sda->index],

					      tmp102_mC_to_reg(val));

	mutex_unlock(&tmp102->lock);

	return status ? : count;

	err = regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(val));

	return err ? : count;

}



static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL,

			  TMP102_TEMP_REG);



static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,

			  tmp102_set_temp, 1);

			  tmp102_set_temp, TMP102_TLOW_REG);



static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,

			  tmp102_set_temp, 2);

			  tmp102_set_temp, TMP102_THIGH_REG);



static struct attribute *tmp102_attrs[] = {

	&sensor_dev_attr_temp1_input.dev_attr.attr,
@@ -185,19 +162,39 @@ static const struct thermal_zone_of_device_ops tmp102_of_thermal_ops = { 
static void tmp102_restore_config(void *data)

{

	struct tmp102 *tmp102 = data;

	struct i2c_client *client = tmp102->client;



	i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,

				     tmp102->config_orig);

	regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig);

}



static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg)

{

	return reg != TMP102_TEMP_REG;

}



static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg)

{

	return reg == TMP102_TEMP_REG;

}



static const struct regmap_config tmp102_regmap_config = {

	.reg_bits = 8,

	.val_bits = 16,

	.max_register = TMP102_THIGH_REG,

	.writeable_reg = tmp102_is_writeable_reg,

	.volatile_reg = tmp102_is_volatile_reg,

	.val_format_endian = REGMAP_ENDIAN_BIG,

	.cache_type = REGCACHE_RBTREE,

	.use_single_rw = true,

};



static int tmp102_probe(struct i2c_client *client,

				  const struct i2c_device_id *id)

{

	struct device *dev = &client->dev;

	struct device *hwmon_dev;

	struct tmp102 *tmp102;

	int status;

	unsigned int regval;

	int err;



	if (!i2c_check_functionality(client->adapter,

				     I2C_FUNC_SMBUS_WORD_DATA)) {
@@ -211,35 +208,36 @@ static int tmp102_probe(struct i2c_client *client, 
		return -ENOMEM;



	i2c_set_clientdata(client, tmp102);

	tmp102->client = client;



	status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);

	if (status < 0) {

	tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config);

	if (IS_ERR(tmp102->regmap))

		return PTR_ERR(tmp102->regmap);



	err = regmap_read(tmp102->regmap, TMP102_CONF_REG, &regval);

	if (err < 0) {

		dev_err(dev, "error reading config register\n");

		return status;

		return err;

	}



	if ((status & ~TMP102_CONFREG_MASK) !=

	if ((regval & ~TMP102_CONFREG_MASK) !=

	    (TMP102_CONF_R0 | TMP102_CONF_R1)) {

		dev_err(dev, "unexpected config register value\n");

		return -ENODEV;

	}



	tmp102->config_orig = status;

	tmp102->config_orig = regval;



	devm_add_action(dev, tmp102_restore_config, tmp102);



	status &= ~TMP102_CONFIG_CLEAR;

	status |= TMP102_CONFIG_SET;

	regval &= ~TMP102_CONFIG_CLEAR;

	regval |= TMP102_CONFIG_SET;



	status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, status);

	if (status < 0) {

	err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval);

	if (err < 0) {

		dev_err(dev, "error writing config register\n");

		return status;

		return err;

	}



	mutex_init(&tmp102->lock);



	tmp102->ready_time = jiffies;

	if (tmp102->config_orig & TMP102_CONF_SD) {

		/*
@@ -268,30 +266,24 @@ static int tmp102_probe(struct i2c_client *client, 
static int tmp102_suspend(struct device *dev)

{

	struct i2c_client *client = to_i2c_client(dev);

	int config;



	config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);

	if (config < 0)

		return config;

	struct tmp102 *tmp102 = i2c_get_clientdata(client);



	config |= TMP102_CONF_SD;

	return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);

	return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,

				  TMP102_CONF_SD, TMP102_CONF_SD);

}



static int tmp102_resume(struct device *dev)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct tmp102 *tmp102 = i2c_get_clientdata(client);

	int config;

	int err;



	config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);

	if (config < 0)

		return config;

	err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,

				 TMP102_CONF_SD, 0);



	tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);



	config &= ~TMP102_CONF_SD;

	return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);

	return err;

}

#endif /* CONFIG_PM */