[PATCH v3 1/3] iio: ad_sigma_delta: Allow to provide custom data register address

[Stefan Popa]

From: Lars-Peter Clausen <l...@metafoo.de>

Some newer devices from the Sigma-Delta ADC family do have their data
register at a different address than the current default address. Add a
parameter to the ad_sigma_delta_info struct which allows to override the
default address.

Signed-off-by: Lars-Peter Clausen <l...@metafoo.de>
Signed-off-by: Stefan Popa <stefan.p...@analog.com>
---
Changes in v2:
        - Added this commit.
Changes in v3:
        - Nothing changed.

 drivers/iio/adc/ad_sigma_delta.c       | 22 +++++++++++++++++-----
 include/linux/iio/adc/ad_sigma_delta.h |  3 +++
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c
index fc95107..ff5f2da 100644
--- a/drivers/iio/adc/ad_sigma_delta.c
+++ b/drivers/iio/adc/ad_sigma_delta.c
@@ -278,6 +278,7 @@ int ad_sigma_delta_single_conversion(struct iio_dev 
*indio_dev,
 {
        struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
        unsigned int sample, raw_sample;
+       unsigned int data_reg;
        int ret = 0;
 
        if (iio_buffer_enabled(indio_dev))
@@ -305,7 +306,12 @@ int ad_sigma_delta_single_conversion(struct iio_dev 
*indio_dev,
        if (ret < 0)
                goto out;
 
-       ret = ad_sd_read_reg(sigma_delta, AD_SD_REG_DATA,
+       if (sigma_delta->info->data_reg != 0)
+               data_reg = sigma_delta->info->data_reg;
+       else
+               data_reg = AD_SD_REG_DATA;
+
+       ret = ad_sd_read_reg(sigma_delta, data_reg,
                DIV_ROUND_UP(chan->scan_type.realbits + chan->scan_type.shift, 
8),
                &raw_sample);
 
@@ -392,6 +398,7 @@ static irqreturn_t ad_sd_trigger_handler(int irq, void *p)
        struct iio_dev *indio_dev = pf->indio_dev;
        struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
        unsigned int reg_size;
+       unsigned int data_reg;
        uint8_t data[16];
        int ret;
 
@@ -401,18 +408,23 @@ static irqreturn_t ad_sd_trigger_handler(int irq, void *p)
                        indio_dev->channels[0].scan_type.shift;
        reg_size = DIV_ROUND_UP(reg_size, 8);
 
+       if (sigma_delta->info->data_reg != 0)
+               data_reg = sigma_delta->info->data_reg;
+       else
+               data_reg = AD_SD_REG_DATA;
+
        switch (reg_size) {
        case 4:
        case 2:
        case 1:
-               ret = ad_sd_read_reg_raw(sigma_delta, AD_SD_REG_DATA,
-                       reg_size, &data[0]);
+               ret = ad_sd_read_reg_raw(sigma_delta, data_reg, reg_size,
+                       &data[0]);
                break;
        case 3:
                /* We store 24 bit samples in a 32 bit word. Keep the upper
                 * byte set to zero. */
-               ret = ad_sd_read_reg_raw(sigma_delta, AD_SD_REG_DATA,
-                       reg_size, &data[1]);
+               ret = ad_sd_read_reg_raw(sigma_delta, data_reg, reg_size,
+                       &data[1]);
                break;
        }
 
diff --git a/include/linux/iio/adc/ad_sigma_delta.h 
b/include/linux/iio/adc/ad_sigma_delta.h
index 730ead1..7e84351 100644
--- a/include/linux/iio/adc/ad_sigma_delta.h
+++ b/include/linux/iio/adc/ad_sigma_delta.h
@@ -39,6 +39,8 @@ struct iio_dev;
  *             if there is just one read-only sample data shift register.
  * @addr_shift: Shift of the register address in the communications register.
  * @read_mask: Mask for the communications register having the read bit set.
+ * @data_reg: Address of the data register, if 0 the default address of 0x3 
will
+ *   be used.
  */
 struct ad_sigma_delta_info {
        int (*set_channel)(struct ad_sigma_delta *, unsigned int channel);
@@ -47,6 +49,7 @@ struct ad_sigma_delta_info {
        bool has_registers;
        unsigned int addr_shift;
        unsigned int read_mask;
+       unsigned int data_reg;
 };
 
 /**
-- 
2.7.4