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hwmon: (ads2828) Convert to use regmap

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Simplify code and reduce code size by using regmap to access i2c registers.

Reviewed-and-Tested-by: Robert Rosengren <robert.rosengren@axis.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Guenter Roeck 2015-01-16 10:08:27 -08:00
parent 9130880a1c
commit bea0bab0fc
2 changed files with 27 additions and 44 deletions
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1
drivers/hwmon/Kconfig
View File

@ -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

70
drivers/hwmon/ads7828.c
View File

@ -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, &regval);
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);