hwmon: (ads2828) Convert to use regmap

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>

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index c24394086b4015ad08c1587b0cd562e22f8562ec..d931cbbed24069a072385725f5c1fd454e04acdb 100644 (file)
--- 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 a622d40eec1788ca73e138e41a7518aa98049cd5..071f779d5e484a311567b32b624b4ebe3818a92b 100644 (file)
--- 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, &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);