]> git.karo-electronics.de Git - linux-beck.git/commitdiff
iio:magnetometer:ak8975: triggered buffer support
authorGregor Boirie <gregor.boirie@parrot.com>
Fri, 8 Apr 2016 15:09:08 +0000 (17:09 +0200)
committerJonathan Cameron <jic23@kernel.org>
Sun, 10 Apr 2016 12:36:23 +0000 (13:36 +0100)
This will be used together with an external trigger (e.g hrtimer based
software trigger).

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
drivers/iio/magnetometer/Kconfig
drivers/iio/magnetometer/ak8975.c

index 021dc5361f53e8de2a5ebd7e18a58912c3a41c43..d9834ed023db7134149c1a725263c0b9ffd779f6 100644 (file)
@@ -9,6 +9,8 @@ config AK8975
        tristate "Asahi Kasei AK 3-Axis Magnetometer"
        depends on I2C
        depends on GPIOLIB || COMPILE_TEST
+       select IIO_BUFFER
+       select IIO_TRIGGERED_BUFFER
        help
          Say yes here to build support for Asahi Kasei AK8975, AK8963,
          AK09911 or AK09912 3-Axis Magnetometer.
index 48d127a45d90d9dfd05d05e239f117db462d3b04..1e6898141f884bd0e461a33fc4045cbb3fb08dcd 100644 (file)
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/regulator/consumer.h>
+
 /*
  * Register definitions, as well as various shifts and masks to get at the
  * individual fields of the registers.
@@ -633,22 +639,15 @@ static int wait_conversion_complete_interrupt(struct ak8975_data *data)
        return ret > 0 ? 0 : -ETIME;
 }
 
-/*
- * Emits the raw flux value for the x, y, or z axis.
- */
-static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
+static int ak8975_start_read_axis(struct ak8975_data *data,
+                                 const struct i2c_client *client)
 {
-       struct ak8975_data *data = iio_priv(indio_dev);
-       struct i2c_client *client = data->client;
-       int ret;
-
-       mutex_lock(&data->lock);
-
        /* Set up the device for taking a sample. */
-       ret = ak8975_set_mode(data, MODE_ONCE);
+       int ret = ak8975_set_mode(data, MODE_ONCE);
+
        if (ret < 0) {
                dev_err(&client->dev, "Error in setting operating mode\n");
-               goto exit;
+               return ret;
        }
 
        /* Wait for the conversion to complete. */
@@ -659,7 +658,7 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
        else
                ret = wait_conversion_complete_polled(data);
        if (ret < 0)
-               goto exit;
+               return ret;
 
        /* This will be executed only for non-interrupt based waiting case */
        if (ret & data->def->ctrl_masks[ST1_DRDY]) {
@@ -667,32 +666,45 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
                                               data->def->ctrl_regs[ST2]);
                if (ret < 0) {
                        dev_err(&client->dev, "Error in reading ST2\n");
-                       goto exit;
+                       return ret;
                }
                if (ret & (data->def->ctrl_masks[ST2_DERR] |
                           data->def->ctrl_masks[ST2_HOFL])) {
                        dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
-                       ret = -EINVAL;
-                       goto exit;
+                       return -EINVAL;
                }
        }
 
-       /* Read the flux value from the appropriate register
-          (the register is specified in the iio device attributes). */
-       ret = i2c_smbus_read_word_data(client, data->def->data_regs[index]);
-       if (ret < 0) {
-               dev_err(&client->dev, "Read axis data fails\n");
+       return 0;
+}
+
+/* Retrieve raw flux value for one of the x, y, or z axis.  */
+static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
+{
+       struct ak8975_data *data = iio_priv(indio_dev);
+       const struct i2c_client *client = data->client;
+       const struct ak_def *def = data->def;
+       int ret;
+
+       mutex_lock(&data->lock);
+
+       ret = ak8975_start_read_axis(data, client);
+       if (ret)
+               goto exit;
+
+       ret = i2c_smbus_read_word_data(client, def->data_regs[index]);
+       if (ret < 0)
                goto exit;
-       }
 
        mutex_unlock(&data->lock);
 
        /* Clamp to valid range. */
-       *val = clamp_t(s16, ret, -data->def->range, data->def->range);
+       *val = clamp_t(s16, ret, -def->range, def->range);
        return IIO_VAL_INT;
 
 exit:
        mutex_unlock(&data->lock);
+       dev_err(&client->dev, "Error in reading axis\n");
        return ret;
 }
 
@@ -722,12 +734,22 @@ static int ak8975_read_raw(struct iio_dev *indio_dev,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |          \
                             BIT(IIO_CHAN_INFO_SCALE),                  \
                .address = index,                                       \
+               .scan_index = index,                                    \
+               .scan_type = {                                          \
+                       .sign = 's',                                    \
+                       .realbits = 16,                                 \
+                       .storagebits = 16,                              \
+                       .endianness = IIO_CPU                           \
+               }                                                       \
        }
 
 static const struct iio_chan_spec ak8975_channels[] = {
        AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),
+       IIO_CHAN_SOFT_TIMESTAMP(3),
 };
 
+static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };
+
 static const struct iio_info ak8975_info = {
        .read_raw = &ak8975_read_raw,
        .driver_module = THIS_MODULE,
@@ -756,6 +778,56 @@ static const char *ak8975_match_acpi_device(struct device *dev,
        return dev_name(dev);
 }
 
+static void ak8975_fill_buffer(struct iio_dev *indio_dev)
+{
+       struct ak8975_data *data = iio_priv(indio_dev);
+       const struct i2c_client *client = data->client;
+       const struct ak_def *def = data->def;
+       int ret;
+       s16 buff[8]; /* 3 x 16 bits axis values + 1 aligned 64 bits timestamp */
+
+       mutex_lock(&data->lock);
+
+       ret = ak8975_start_read_axis(data, client);
+       if (ret)
+               goto unlock;
+
+       /*
+        * For each axis, read the flux value from the appropriate register
+        * (the register is specified in the iio device attributes).
+        */
+       ret = i2c_smbus_read_i2c_block_data_or_emulated(client,
+                                                       def->data_regs[0],
+                                                       3 * sizeof(buff[0]),
+                                                       (u8 *)buff);
+       if (ret < 0)
+               goto unlock;
+
+       mutex_unlock(&data->lock);
+
+       /* Clamp to valid range. */
+       buff[0] = clamp_t(s16, le16_to_cpu(buff[0]), -def->range, def->range);
+       buff[1] = clamp_t(s16, le16_to_cpu(buff[1]), -def->range, def->range);
+       buff[2] = clamp_t(s16, le16_to_cpu(buff[2]), -def->range, def->range);
+
+       iio_push_to_buffers_with_timestamp(indio_dev, buff, iio_get_time_ns());
+       return;
+
+unlock:
+       mutex_unlock(&data->lock);
+       dev_err(&client->dev, "Error in reading axes block\n");
+}
+
+static irqreturn_t ak8975_handle_trigger(int irq, void *p)
+{
+       const struct iio_poll_func *pf = p;
+       struct iio_dev *indio_dev = pf->indio_dev;
+
+       ak8975_fill_buffer(indio_dev);
+       iio_trigger_notify_done(indio_dev->trig);
+       return IRQ_HANDLED;
+}
+
 static int ak8975_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
 {
@@ -845,15 +917,27 @@ static int ak8975_probe(struct i2c_client *client,
        indio_dev->channels = ak8975_channels;
        indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);
        indio_dev->info = &ak8975_info;
+       indio_dev->available_scan_masks = ak8975_scan_masks;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->name = name;
 
-       err = iio_device_register(indio_dev);
-       if (err)
+       err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,
+                                        NULL);
+       if (err) {
+               dev_err(&client->dev, "triggered buffer setup failed\n");
                goto power_off;
+       }
+
+       err = iio_device_register(indio_dev);
+       if (err) {
+               dev_err(&client->dev, "device register failed\n");
+               goto cleanup_buffer;
+       }
 
        return 0;
 
+cleanup_buffer:
+       iio_triggered_buffer_cleanup(indio_dev);
 power_off:
        ak8975_power_off(client);
        return err;
@@ -864,6 +948,7 @@ static int ak8975_remove(struct i2c_client *client)
        struct iio_dev *indio_dev = i2c_get_clientdata(client);
 
        iio_device_unregister(indio_dev);
+       iio_triggered_buffer_cleanup(indio_dev);
        ak8975_power_off(client);
 
        return 0;