Simplify code and reduce code size by using regmap to access i2c registers.
Cc: Robert Rosengren <robert.rosengren@xxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
v2: Drop byte swapping code; it is handled by regmap internally
Note that the SMBUs word access code in regmap has a bug, resulting
in byte swapped accesses if the i2c controller only supports SMBus
accesses. I will submit patch to fix the code in the regmap subsystem
separately.
drivers/hwmon/Kconfig | 1 +
drivers/hwmon/ads7828.c | 70 ++++++++++++++++++-------------------------------
2 files changed, 27 insertions(+), 44 deletions(-)
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index b1aaf93..9ea71ea 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1389,6 +1389,7 @@ config SENSORS_ADS1015
config SENSORS_ADS7828
tristate "Texas Instruments ADS7828 and compatibles"
depends on I2C
+ select REGMAP_I2C
help
If you say yes here you get support for Texas Instruments ADS7828 and
ADS7830 8-channel A/D converters. ADS7828 resolution is 12-bit, while
diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c
index a622d40..071f779 100644
--- a/drivers/hwmon/ads7828.c
+++ b/drivers/hwmon/ads7828.c
@@ -30,14 +30,12 @@
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/init.h>
-#include <linux/jiffies.h>
#include <linux/module.h>
-#include <linux/mutex.h>
#include <linux/platform_data/ads7828.h>
+#include <linux/regmap.h>
#include <linux/slab.h>
/* The ADS7828 registers */
-#define ADS7828_NCH 8 /* 8 channels supported */
#define ADS7828_CMD_SD_SE 0x80 /* Single ended inputs */
#define ADS7828_CMD_PD1 0x04 /* Internal vref OFF && A/D ON */
#define ADS7828_CMD_PD3 0x0C /* Internal vref ON && A/D ON */
@@ -50,17 +48,12 @@ enum ads7828_chips { ads7828, ads7830 };
/* Client specific data */
struct ads7828_data {
- struct i2c_client *client;
- struct mutex update_lock; /* Mutex protecting updates */
- unsigned long last_updated; /* Last updated time (in jiffies) */
- u16 adc_input[ADS7828_NCH]; /* ADS7828_NCH samples */
- bool valid; /* Validity flag */
+ struct regmap *regmap;
bool diff_input; /* Differential input */
bool ext_vref; /* External voltage reference */
unsigned int vref_mv; /* voltage reference value */
u8 cmd_byte; /* Command byte without channel bits */
unsigned int lsb_resol; /* Resolution of the ADC sample LSB */
- s32 (*read_channel)(const struct i2c_client *client, u8 command);
};
/* Command byte C2,C1,C0 - see datasheet */
@@ -69,42 +62,22 @@ static inline u8 ads7828_cmd_byte(u8 cmd, int ch)
return cmd | (((ch >> 1) | (ch & 0x01) << 2) << 4);
}
-/* Update data for the device (all 8 channels) */
-static struct ads7828_data *ads7828_update_device(struct device *dev)
-{
- struct ads7828_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 + HZ / 2)
- || !data->valid) {
- unsigned int ch;
- dev_dbg(&client->dev, "Starting ads7828 update\n");
-
- for (ch = 0; ch < ADS7828_NCH; ch++) {
- u8 cmd = ads7828_cmd_byte(data->cmd_byte, ch);
- data->adc_input[ch] = data->read_channel(client, cmd);
- }
- data->last_updated = jiffies;
- data->valid = true;
- }
-
- mutex_unlock(&data->update_lock);
-
- return data;
-}
-
/* sysfs callback function */
static ssize_t ads7828_show_in(struct device *dev, struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
- struct ads7828_data *data = ads7828_update_device(dev);
- unsigned int value = DIV_ROUND_CLOSEST(data->adc_input[attr->index] *
- data->lsb_resol, 1000);
+ struct ads7828_data *data = dev_get_drvdata(dev);
+ u8 cmd = ads7828_cmd_byte(data->cmd_byte, attr->index);
+ unsigned int regval;
+ int err;
- return sprintf(buf, "%d\n", value);
+ err = regmap_read(data->regmap, cmd, ®val);
+ if (err < 0)
+ return err;
+
+ return sprintf(buf, "%d\n",
+ DIV_ROUND_CLOSEST(regval * data->lsb_resol, 1000));
}
static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ads7828_show_in, NULL, 0);
@@ -130,6 +103,16 @@ static struct attribute *ads7828_attrs[] = {
ATTRIBUTE_GROUPS(ads7828);
+static const struct regmap_config ads2828_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 16,
+};
+
+static const struct regmap_config ads2830_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
static int ads7828_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -160,19 +143,18 @@ static int ads7828_probe(struct i2c_client *client,
/* ADS7828 uses 12-bit samples, while ADS7830 is 8-bit */
if (id->driver_data == ads7828) {
data->lsb_resol = DIV_ROUND_CLOSEST(data->vref_mv * 1000, 4096);
- data->read_channel = i2c_smbus_read_word_swapped;
+ data->regmap = devm_regmap_init_i2c(client,
+ &ads2828_regmap_config);
} else {
data->lsb_resol = DIV_ROUND_CLOSEST(data->vref_mv * 1000, 256);
- data->read_channel = i2c_smbus_read_byte_data;
+ data->regmap = devm_regmap_init_i2c(client,
+ &ads2830_regmap_config);
}
data->cmd_byte = data->ext_vref ? ADS7828_CMD_PD1 : ADS7828_CMD_PD3;
if (!data->diff_input)
data->cmd_byte |= ADS7828_CMD_SD_SE;
- data->client = client;
- mutex_init(&data->update_lock);
-
hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
data,
ads7828_groups);
--
2.1.0
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