iio: ti-adc0832: add triggered buffer support

This adds triggered buffer support for the ti-adc0832 driver.  Tested with
ADC0831 and ADC0832 by using SYSFS trigger.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 60426685d55d80e01b370a94d45f8bb2cf8d13fa..c3fe98d2dc3bbd1e18393ba8f2663d82a0d01dae 100644 (file)
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -459,6 +459,8 @@ config TI_ADC081C
 config TI_ADC0832
        tristate "Texas Instruments ADC0831/ADC0832/ADC0834/ADC0838"
        depends on SPI
+       select IIO_BUFFER
+       select IIO_TRIGGERED_BUFFER
        help
          If you say yes here you get support for Texas Instruments ADC0831,
          ADC0832, ADC0834, ADC0838 ADC chips.

diff --git a/drivers/iio/adc/ti-adc0832.c b/drivers/iio/adc/ti-adc0832.c
index f4ba23effe9ad9c71fd9d947c3259cc4bbbd2537..e952e94a14afaffba57c04c283bfc01230213c06 100644 (file)
--- a/drivers/iio/adc/ti-adc0832.c
+++ b/drivers/iio/adc/ti-adc0832.c
@@ -14,6 +14,10 @@
 #include <linux/spi/spi.h>
 #include <linux/iio/iio.h>
 #include <linux/regulator/consumer.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
 
 enum {
        adc0831,
@@ -38,10 +42,16 @@ struct adc0832 {
                .indexed = 1,                                           \
                .channel = chan,                                        \
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
-               .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE)    \
+               .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
+               .scan_index = chan,                                     \
+               .scan_type = {                                          \
+                       .sign = 'u',                                    \
+                       .realbits = 8,                                  \
+                       .storagebits = 8,                               \
+               },                                                      \
        }
 
-#define ADC0832_VOLTAGE_CHANNEL_DIFF(chan1, chan2)                     \
+#define ADC0832_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si)                 \
        {                                                               \
                .type = IIO_VOLTAGE,                                    \
                .indexed = 1,                                           \
@@ -49,18 +59,26 @@ struct adc0832 {
                .channel2 = (chan2),                                    \
                .differential = 1,                                      \
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
-               .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE)    \
+               .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
+               .scan_index = si,                                       \
+               .scan_type = {                                          \
+                       .sign = 'u',                                    \
+                       .realbits = 8,                                  \
+                       .storagebits = 8,                               \
+               },                                                      \
        }
 
 static const struct iio_chan_spec adc0831_channels[] = {
-       ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1, 0),
+       IIO_CHAN_SOFT_TIMESTAMP(1),
 };
 
 static const struct iio_chan_spec adc0832_channels[] = {
        ADC0832_VOLTAGE_CHANNEL(0),
        ADC0832_VOLTAGE_CHANNEL(1),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1, 2),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0, 3),
+       IIO_CHAN_SOFT_TIMESTAMP(4),
 };
 
 static const struct iio_chan_spec adc0834_channels[] = {
@@ -68,10 +86,11 @@ static const struct iio_chan_spec adc0834_channels[] = {
        ADC0832_VOLTAGE_CHANNEL(1),
        ADC0832_VOLTAGE_CHANNEL(2),
        ADC0832_VOLTAGE_CHANNEL(3),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(2, 3),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(3, 2),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1, 4),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0, 5),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(2, 3, 6),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(3, 2, 7),
+       IIO_CHAN_SOFT_TIMESTAMP(8),
 };
 
 static const struct iio_chan_spec adc0838_channels[] = {
@@ -83,14 +102,15 @@ static const struct iio_chan_spec adc0838_channels[] = {
        ADC0832_VOLTAGE_CHANNEL(5),
        ADC0832_VOLTAGE_CHANNEL(6),
        ADC0832_VOLTAGE_CHANNEL(7),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(2, 3),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(3, 2),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(4, 5),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(5, 4),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(6, 7),
-       ADC0832_VOLTAGE_CHANNEL_DIFF(7, 6),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0, 9),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(2, 3, 10),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(3, 2, 11),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(4, 5, 12),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(5, 4, 13),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(6, 7, 14),
+       ADC0832_VOLTAGE_CHANNEL_DIFF(7, 6, 15),
+       IIO_CHAN_SOFT_TIMESTAMP(16),
 };
 
 static int adc0831_adc_conversion(struct adc0832 *adc)
@@ -178,6 +198,42 @@ static const struct iio_info adc0832_info = {
        .driver_module = THIS_MODULE,
 };
 
+static irqreturn_t adc0832_trigger_handler(int irq, void *p)
+{
+       struct iio_poll_func *pf = p;
+       struct iio_dev *indio_dev = pf->indio_dev;
+       struct adc0832 *adc = iio_priv(indio_dev);
+       u8 data[24] = { }; /* 16x 1 byte ADC data + 8 bytes timestamp */
+       int scan_index;
+       int i = 0;
+
+       mutex_lock(&adc->lock);
+
+       for_each_set_bit(scan_index, indio_dev->active_scan_mask,
+                        indio_dev->masklength) {
+               const struct iio_chan_spec *scan_chan =
+                               &indio_dev->channels[scan_index];
+               int ret = adc0832_adc_conversion(adc, scan_chan->channel,
+                                                scan_chan->differential);
+               if (ret < 0) {
+                       dev_warn(&adc->spi->dev,
+                                "failed to get conversion data\n");
+                       goto out;
+               }
+
+               data[i] = ret;
+               i++;
+       }
+       iio_push_to_buffers_with_timestamp(indio_dev, data,
+                                          iio_get_time_ns(indio_dev));
+out:
+       mutex_unlock(&adc->lock);
+
+       iio_trigger_notify_done(indio_dev->trig);
+
+       return IRQ_HANDLED;
+}
+
 static int adc0832_probe(struct spi_device *spi)
 {
        struct iio_dev *indio_dev;
@@ -233,9 +289,20 @@ static int adc0832_probe(struct spi_device *spi)
 
        spi_set_drvdata(spi, indio_dev);
 
+       ret = iio_triggered_buffer_setup(indio_dev, NULL,
+                                        adc0832_trigger_handler, NULL);
+       if (ret)
+               goto err_reg_disable;
+
        ret = iio_device_register(indio_dev);
        if (ret)
-               regulator_disable(adc->reg);
+               goto err_buffer_cleanup;
+
+       return 0;
+err_buffer_cleanup:
+       iio_triggered_buffer_cleanup(indio_dev);
+err_reg_disable:
+       regulator_disable(adc->reg);
 
        return ret;
 }
@@ -246,6 +313,7 @@ static int adc0832_remove(struct spi_device *spi)
        struct adc0832 *adc = iio_priv(indio_dev);
 
        iio_device_unregister(indio_dev);
+       iio_triggered_buffer_cleanup(indio_dev);
        regulator_disable(adc->reg);
 
        return 0;