Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger...
[firefly-linux-kernel-4.4.55.git] / drivers / hwmon / ads7828.c
index a622d40eec1788ca73e138e41a7518aa98049cd5..bce4e9ff21bff76606484f0a04ad1bf52b1ffee2 100644 (file)
 #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 +48,9 @@ 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 */
-       bool diff_input;                /* Differential input */
-       bool ext_vref;                  /* External voltage reference */
-       unsigned int vref_mv;           /* voltage reference value */
+       struct regmap *regmap;
        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 +59,22 @@ 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 +100,16 @@ 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)
 {
@@ -137,42 +117,40 @@ static int ads7828_probe(struct i2c_client *client,
        struct ads7828_platform_data *pdata = dev_get_platdata(dev);
        struct ads7828_data *data;
        struct device *hwmon_dev;
+       unsigned int vref_mv = ADS7828_INT_VREF_MV;
+       bool diff_input = false;
+       bool ext_vref = false;
 
        data = devm_kzalloc(dev, sizeof(struct ads7828_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;
 
        if (pdata) {
-               data->diff_input = pdata->diff_input;
-               data->ext_vref = pdata->ext_vref;
-               if (data->ext_vref)
-                       data->vref_mv = pdata->vref_mv;
+               diff_input = pdata->diff_input;
+               ext_vref = pdata->ext_vref;
+               if (ext_vref && pdata->vref_mv)
+                       vref_mv = pdata->vref_mv;
        }
 
-       /* Bound Vref with min/max values if it was provided */
-       if (data->vref_mv)
-               data->vref_mv = clamp_val(data->vref_mv,
-                                         ADS7828_EXT_VREF_MV_MIN,
-                                         ADS7828_EXT_VREF_MV_MAX);
-       else
-               data->vref_mv = ADS7828_INT_VREF_MV;
+       /* Bound Vref with min/max values */
+       vref_mv = clamp_val(vref_mv, ADS7828_EXT_VREF_MV_MIN,
+                           ADS7828_EXT_VREF_MV_MAX);
 
        /* 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->lsb_resol = DIV_ROUND_CLOSEST(vref_mv * 1000, 4096);
+               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->lsb_resol = DIV_ROUND_CLOSEST(vref_mv * 1000, 256);
+               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 = ext_vref ? ADS7828_CMD_PD1 : ADS7828_CMD_PD3;
+       if (!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);