OpenE2K
/
linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

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: Nishanth Menon <nm@ti.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Guenter Roeck 2016-06-20 09:55:46 -07:00
parent a9f92ccf33
commit 28a340db90
2 changed files with 71 additions and 78 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/hwmon/Kconfig
View File

@ -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.

148
drivers/hwmon/tmp102.c
View File

@ -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;
struct tmp102 *tmp102 = i2c_get_clientdata(client);
config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
if (config < 0)
return config;
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 */