staging:iio:adc:ad7291: Add regulator, reference voltage and scale handling

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/iio/adc/ad7291.c b/drivers/staging/iio/adc/ad7291.c
index b34af692612f5ee42dd85d2af0348254c945d004..84c638d4f34594b853486c43f729922c6002beda 100644 (file)
--- a/drivers/staging/iio/adc/ad7291.c
+++ b/drivers/staging/iio/adc/ad7291.c
@@ -14,6 +14,8 @@
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/regulator/consumer.h>
+#include <linux/err.h>
 
 #include "../iio.h"
 #include "../sysfs.h"
@@ -27,8 +29,8 @@
  *
  * The noise-delayed bit as per datasheet suggestion is always enabled.
  *
- * Extref control should be based on regulator provision - not handled.
  */
+
 /*
  * AD7291 registers definition
  */
@@ -61,16 +63,21 @@
  * AD7291 value masks
  */
 #define AD7291_CHANNEL_MASK            0xF000
+#define AD7291_BITS                    12
 #define AD7291_VALUE_MASK              0xFFF
 #define AD7291_T_VALUE_SIGN            0x400
 #define AD7291_T_VALUE_FLOAT_OFFSET    2
 #define AD7291_T_VALUE_FLOAT_MASK      0x2
 
+#define AD7291_BITS                    12
+
 struct ad7291_chip_info {
-       struct i2c_client *client;
-       u16 command;
-       u8 c_mask;      /* Active voltage channels for events */
-       struct mutex state_lock;
+       struct i2c_client       *client;
+       struct regulator        *reg;
+       u16                     int_vref_mv;
+       u16                     command;
+       u8                      c_mask; /* Active voltage channels for events */
+       struct mutex            state_lock;
 };
 
 static int ad7291_i2c_read(struct ad7291_chip_info *chip, u8 reg, u16 *data)
@@ -420,6 +427,7 @@ static int ad7291_read_raw(struct iio_dev *indio_dev,
 {
        int ret;
        struct ad7291_chip_info *chip = iio_priv(indio_dev);
+       unsigned int scale_uv;
        u16 regval;
        s16 signval;
 
@@ -471,6 +479,11 @@ static int ad7291_read_raw(struct iio_dev *indio_dev,
                        signval = (s16)((swab16((u16)ret) & 0x0FFF) << 4) >> 4;
                        *val = signval;
                        return IIO_VAL_INT;
+       case (1 << IIO_CHAN_INFO_SCALE_SHARED):
+               scale_uv = (chip->int_vref_mv * 1000) >> AD7291_BITS;
+               *val =  scale_uv / 1000;
+               *val2 = (scale_uv % 1000) * 1000;
+               return IIO_VAL_INT_PLUS_MICRO;
        default:
                return -EINVAL;
        }
@@ -479,6 +492,7 @@ static int ad7291_read_raw(struct iio_dev *indio_dev,
 #define AD7291_VOLTAGE_CHAN(_chan)                                     \
 {                                                                      \
        .type = IIO_VOLTAGE,                                            \
+       .info_mask = (1 << IIO_CHAN_INFO_SCALE_SHARED),                 \
        .indexed = 1,                                                   \
        .channel = _chan,                                               \
        .event_mask = IIO_EV_BIT(IIO_EV_TYPE_THRESH, IIO_EV_DIR_RISING)|\
@@ -524,7 +538,7 @@ static int __devinit ad7291_probe(struct i2c_client *client,
 {
        struct ad7291_chip_info *chip;
        struct iio_dev *indio_dev;
-       int ret = 0;
+       int ret = 0, voltage_uv = 0;
 
        indio_dev = iio_allocate_device(sizeof(*chip));
        if (indio_dev == NULL) {
@@ -532,6 +546,15 @@ static int __devinit ad7291_probe(struct i2c_client *client,
                goto error_ret;
        }
        chip = iio_priv(indio_dev);
+
+       chip->reg = regulator_get(&client->dev, "vcc");
+       if (!IS_ERR(chip->reg)) {
+               ret = regulator_enable(chip->reg);
+               if (ret)
+                       goto error_put_reg;
+               voltage_uv = regulator_get_voltage(chip->reg);
+       }
+
        mutex_init(&chip->state_lock);
        /* this is only used for device removal purposes */
        i2c_set_clientdata(client, indio_dev);
@@ -540,6 +563,13 @@ static int __devinit ad7291_probe(struct i2c_client *client,
        /* Tsense always enabled */
        chip->command = AD7291_NOISE_DELAY | AD7291_T_SENSE_MASK;
 
+       if (voltage_uv) {
+               chip->int_vref_mv = voltage_uv / 1000;
+               chip->command |= AD7291_EXT_REF;
+       } else {
+               chip->int_vref_mv = 2500; /* Build-in ref */
+       }
+
        indio_dev->name = id->name;
        indio_dev->channels = ad7291_channels;
        indio_dev->num_channels = ARRAY_SIZE(ad7291_channels);
@@ -556,7 +586,7 @@ static int __devinit ad7291_probe(struct i2c_client *client,
                                           id->name,
                                           indio_dev);
                if (ret)
-                       goto error_free_dev;
+                       goto error_disable_reg;
 
                /* set irq polarity low level */
                chip->command |= AD7291_ALERT_POLARITY;
@@ -572,7 +602,7 @@ static int __devinit ad7291_probe(struct i2c_client *client,
        if (ret)
                goto error_unreg_irq;
 
-       dev_info(&client->dev, "%s temperature sensor registered.\n",
+       dev_info(&client->dev, "%s ADC registered.\n",
                         id->name);
 
        return 0;
@@ -580,7 +610,13 @@ static int __devinit ad7291_probe(struct i2c_client *client,
 error_unreg_irq:
        if (client->irq)
                free_irq(client->irq, indio_dev);
-error_free_dev:
+error_disable_reg:
+       if (!IS_ERR(chip->reg))
+               regulator_disable(chip->reg);
+error_put_reg:
+       if (!IS_ERR(chip->reg))
+               regulator_put(chip->reg);
+
        iio_free_device(indio_dev);
 error_ret:
        return ret;
@@ -589,9 +625,16 @@ error_ret:
 static int __devexit ad7291_remove(struct i2c_client *client)
 {
        struct iio_dev *indio_dev = i2c_get_clientdata(client);
+       struct ad7291_chip_info *chip = iio_priv(indio_dev);
 
        if (client->irq)
                free_irq(client->irq, indio_dev);
+
+       if (!IS_ERR(chip->reg)) {
+               regulator_disable(chip->reg);
+               regulator_put(chip->reg);
+       }
+
        iio_device_unregister(indio_dev);
 
        return 0;