ti-adc081c: Initial triggered buffer support

Using this requires software triggers like CONFIG_IIO_HRTIMER_TRIGGER.

The device can be configured to do internal periodic sampling but does not
offer some sort of interrupt on data ready. Interrupts can only trigger when
values get out of a specific range.

Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 64 insertions, 13 deletions

diff --git a/drivers/iio/adc/ti-adc081c.c b/drivers/iio/adc/ti-adc081c.c
index b977340fbdb8..9fd032d9f402 100644
--- a/drivers/iio/adc/ti-adc081c.c
+++ b/drivers/iio/adc/ti-adc081c.c
@@ -24,6 +24,9 @@
 #include <linux/of.h>
 
 #include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 #include <linux/regulator/consumer.h>
 
 struct adc081c {
@@ -69,21 +72,42 @@ static int adc081c_read_raw(struct iio_dev *iio,
         return -EINVAL;
 }
 
-static const struct iio_chan_spec adc081c_channel = {
-        .type = IIO_VOLTAGE,
-        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
-        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
-};
+#define ADCxx1C_CHAN(_bits) {                                   \
+        .type = IIO_VOLTAGE,                                    \
+        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
+        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
+        .scan_type = {                                          \
+                .sign = 'u',                                    \
+                .realbits = (_bits),                            \
+                .storagebits = 16,                              \
+                .shift = 12 - (_bits),                          \
+                .endianness = IIO_CPU,                          \
+        },                                                      \
+}
+
+#define DEFINE_ADCxx1C_CHANNELS(_name, _bits)                           \
+        static const struct iio_chan_spec _name ## _channels[] = {      \
+                ADCxx1C_CHAN((_bits)),                                  \
+                IIO_CHAN_SOFT_TIMESTAMP(1),                             \
+        };                                                              \
+
+#define ADC081C_NUM_CHANNELS 2
 
 struct adcxx1c_model {
+        const struct iio_chan_spec* channels;
         int bits;
 };
 
-#define ADCxx1C_MODEL(_bits)                                            \
+#define ADCxx1C_MODEL(_name, _bits)                                     \
         {                                                               \
+                .channels = _name ## _channels,                         \
                 .bits = (_bits),                                        \
         }
 
+DEFINE_ADCxx1C_CHANNELS(adc081c,  8);
+DEFINE_ADCxx1C_CHANNELS(adc101c, 10);
+DEFINE_ADCxx1C_CHANNELS(adc121c, 12);
+
 /* Model ids are indexes in _models array */
 enum adcxx1c_model_id {
         ADC081C = 0,
@@ -92,9 +116,9 @@ enum adcxx1c_model_id {
 };
 
 static struct adcxx1c_model adcxx1c_models[] = {
-        ADCxx1C_MODEL( 8),
-        ADCxx1C_MODEL(10),
-        ADCxx1C_MODEL(12),
+        ADCxx1C_MODEL(adc081c,  8),
+        ADCxx1C_MODEL(adc101c, 10),
+        ADCxx1C_MODEL(adc121c, 12),
 };
 
 static const struct iio_info adc081c_info = {
@@ -102,6 +126,24 @@ static const struct iio_info adc081c_info = {
         .driver_module = THIS_MODULE,
 };
 
+static irqreturn_t adc081c_trigger_handler(int irq, void *p)
+{
+        struct iio_poll_func *pf = p;
+        struct iio_dev *indio_dev = pf->indio_dev;
+        struct adc081c *data = iio_priv(indio_dev);
+        u16 buf[8]; /* 2 bytes data + 6 bytes padding + 8 bytes timestamp */
+        int ret;
+
+        ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES);
+        if (ret < 0)
+                goto out;
+        buf[0] = ret;
+        iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns());
+out:
+        iio_trigger_notify_done(indio_dev->trig);
+        return IRQ_HANDLED;
+}
+
 static int adc081c_probe(struct i2c_client *client,
                          const struct i2c_device_id *id)
 {
@@ -134,18 +176,26 @@ static int adc081c_probe(struct i2c_client *client,
         iio->modes = INDIO_DIRECT_MODE;
         iio->info = &adc081c_info;
 
-        iio->channels = &adc081c_channel;
-        iio->num_channels = 1;
+        iio->channels = model->channels;
+        iio->num_channels = ADC081C_NUM_CHANNELS;
+
+        err = iio_triggered_buffer_setup(iio, NULL, adc081c_trigger_handler, NULL);
+        if (err < 0) {
+                dev_err(&client->dev, "iio triggered buffer setup failed\n");
+                goto err_regulator_disable;
+        }
 
         err = iio_device_register(iio);
         if (err < 0)
-                goto regulator_disable;
+                goto err_buffer_cleanup;
 
         i2c_set_clientdata(client, iio);
 
         return 0;
 
-regulator_disable:
+err_buffer_cleanup:
+        iio_triggered_buffer_cleanup(iio);
+err_regulator_disable:
         regulator_disable(adc->ref);
 
         return err;
@@ -157,6 +207,7 @@ static int adc081c_remove(struct i2c_client *client)
         struct adc081c *adc = iio_priv(iio);
 
         iio_device_unregister(iio);
+        iio_triggered_buffer_cleanup(iio);
         regulator_disable(adc->ref);
 
         return 0;