iio: accel: Add triggered buffer support for BMA220

Signed-off-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 63 insertions, 2 deletions

diff --git a/drivers/iio/accel/bma220_spi.c b/drivers/iio/accel/bma220_spi.c
index 7343575e84ba..1098d10df8e8 100644
--- a/drivers/iio/accel/bma220_spi.c
+++ b/drivers/iio/accel/bma220_spi.c
@@ -11,9 +11,12 @@
 #include <linux/acpi.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/iio/buffer.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/spi/spi.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 
 #define BMA220_REG_ID                           0x00
 #define BMA220_REG_ACCEL_X                      0x02
@@ -39,8 +42,22 @@
         .channel2 = IIO_MOD_##axis,                                     \
         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),           \
+        .scan_index = index,                                            \
+        .scan_type = {                                                  \
+                .sign = 's',                                            \
+                .realbits = 6,                                          \
+                .storagebits = 8,                                       \
+                .shift = BMA220_DATA_SHIFT,                             \
+                .endianness = IIO_CPU,                                  \
+        },                                                              \
 }
 
+enum bma220_axis {
+        AXIS_X,
+        AXIS_Y,
+        AXIS_Z,
+};
+
 static IIO_CONST_ATTR(in_accel_scale_available, BMA220_SCALE_AVAILABLE);
 
 static struct attribute *bma220_attributes[] = {
@@ -59,6 +76,7 @@ static const int bma220_scale_table[][4] = {
 struct bma220_data {
         struct spi_device *spi_device;
         struct mutex lock;
+        s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 8x8 timestamp */
         u8 tx_buf[2] ____cacheline_aligned;
 };
 
@@ -66,6 +84,7 @@ static const struct iio_chan_spec bma220_channels[] = {
         BMA220_ACCEL_CHANNEL(0, BMA220_REG_ACCEL_X, X),
         BMA220_ACCEL_CHANNEL(1, BMA220_REG_ACCEL_Y, Y),
         BMA220_ACCEL_CHANNEL(2, BMA220_REG_ACCEL_Z, Z),
+        IIO_CHAN_SOFT_TIMESTAMP(3),
 };
 
 static inline int bma220_read_reg(struct spi_device *spi, u8 reg)
@@ -73,6 +92,35 @@ static inline int bma220_read_reg(struct spi_device *spi, u8 reg)
         return spi_w8r8(spi, reg | BMA220_READ_MASK);
 }
 
+static const unsigned long bma220_accel_scan_masks[] = {
+        BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
+        0
+};
+
+static irqreturn_t bma220_trigger_handler(int irq, void *p)
+{
+        int ret;
+        struct iio_poll_func *pf = p;
+        struct iio_dev *indio_dev = pf->indio_dev;
+        struct bma220_data *data = iio_priv(indio_dev);
+        struct spi_device *spi = data->spi_device;
+
+        mutex_lock(&data->lock);
+        data->tx_buf[0] = BMA220_REG_ACCEL_X | BMA220_READ_MASK;
+        ret = spi_write_then_read(spi, data->tx_buf, 1, data->buffer,
+                                  ARRAY_SIZE(bma220_channels) - 1);
+        if (ret < 0)
+                goto err;
+
+        iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+                                           pf->timestamp);
+err:
+        mutex_unlock(&data->lock);
+        iio_trigger_notify_done(indio_dev->trig);
+
+        return IRQ_HANDLED;
+}
+
 static int bma220_read_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int *val, int *val2, long mask)
@@ -199,18 +247,30 @@ static int bma220_probe(struct spi_device *spi)
         indio_dev->modes = INDIO_DIRECT_MODE;
         indio_dev->channels = bma220_channels;
         indio_dev->num_channels = ARRAY_SIZE(bma220_channels);
+        indio_dev->available_scan_masks = bma220_accel_scan_masks;
 
         ret = bma220_init(data->spi_device);
         if (ret < 0)
                 return ret;
 
+        ret = iio_triggered_buffer_setup(indio_dev, NULL,
+                                         bma220_trigger_handler, NULL);
+        if (ret < 0) {
+                dev_err(&spi->dev, "iio triggered buffer setup failed\n");
+                goto err_suspend;
+        }
+
         ret = iio_device_register(indio_dev);
         if (ret < 0) {
                 dev_err(&spi->dev, "iio_device_register failed\n");
-                return bma220_deinit(spi);
+                iio_triggered_buffer_cleanup(indio_dev);
+                goto err_suspend;
         }
 
-        return ret;
+        return 0;
+
+err_suspend:
+        return bma220_deinit(spi);
 }
 
 static int bma220_remove(struct spi_device *spi)
@@ -218,6 +278,7 @@ static int bma220_remove(struct spi_device *spi)
         struct iio_dev *indio_dev = spi_get_drvdata(spi);
 
         iio_device_unregister(indio_dev);
+        iio_triggered_buffer_cleanup(indio_dev);
 
         return bma220_deinit(spi);
 }