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Message-Id: <1467258119-14071-3-git-send-email-linux@roeck-us.net>
Date: Wed, 29 Jun 2016 20:41:59 -0700
From: Guenter Roeck <linux@...ck-us.net>
To: Jean Delvare <jdelvare@...e.com>
Cc: Nishanth Menon <nm@...com>, linux-hwmon@...r.kernel.org,
linux-kernel@...r.kernel.org, Guenter Roeck <linux@...ck-us.net>
Subject: [PATCH v3 3/3] 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.
Signed-off-by: Guenter Roeck <linux@...ck-us.net>
---
v3: Add missing 'select REGMAP_I2C'
Fix typo in description
Adjust to changes in patch 1/3
v2: Set use_single_rw to indicate that the chip can not perform
read operations crossing register boundaries.
Use REGCACHE_RBTREE instead REGCACHE_FLAT. REGCACHE_FLAT does not
initialize the cache from the chip unless num_reg_defaults_raw is
provided. If it is provided without actual cache values, it complains
with 'No cache defaults, reading back from HW'. REGCACHE_RBTREE
automatically initializes register values from the chip if no
defaults are provided, and does not complain about it.
drivers/hwmon/Kconfig | 1 +
drivers/hwmon/tmp102.c | 148 +++++++++++++++++++++++--------------------------
2 files changed, 71 insertions(+), 78 deletions(-)
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index ff940075bb90..731378853eea 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1538,6 +1538,7 @@ 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.
diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
index 82a8a29af2e4..a942a2574a4d 100644
--- a/drivers/hwmon/tmp102.c
+++ b/drivers/hwmon/tmp102.c
@@ -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, ®);
+ 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, ®);
+ 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, ®val);
+ 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 */
--
2.5.0
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