iio: accel: Add trigger support for STK8BA50
authorTiberiu Breana <tiberiu.a.breana@intel.com>
Wed, 24 Jun 2015 13:54:46 +0000 (16:54 +0300)
committerJonathan Cameron <jic23@kernel.org>
Sun, 5 Jul 2015 13:41:02 +0000 (14:41 +0100)
Add data-ready interrupts and trigger support for STK8BA50.

Additional changes:
- read_accel now returns raw acceleration data instead of the
  sign_extend32 value
- read_raw will now enable/disable the sensor with each reading

Change-Id: I9c2d7be4256b2dcc5546e4432308ea54f8004333
Signed-off-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
drivers/iio/accel/stk8ba50.c

index 9836880..16cee63 100644 (file)
  */
 
 #include <linux/acpi.h>
+#include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
+#include <linux/interrupt.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/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
 
 #define STK8BA50_REG_XOUT                      0x02
 #define STK8BA50_REG_YOUT                      0x04
@@ -24,6 +30,8 @@
 #define STK8BA50_REG_BWSEL                     0x10
 #define STK8BA50_REG_POWMODE                   0x11
 #define STK8BA50_REG_SWRST                     0x14
+#define STK8BA50_REG_INTEN2                    0x17
+#define STK8BA50_REG_INTMAP2                   0x1A
 
 #define STK8BA50_MODE_NORMAL                   0
 #define STK8BA50_MODE_SUSPEND                  1
 #define STK8BA50_DATA_SHIFT                    6
 #define STK8BA50_RESET_CMD                     0xB6
 #define STK8BA50_SR_1792HZ_IDX                 7
+#define STK8BA50_DREADY_INT_MASK               0x10
+#define STK8BA50_DREADY_INT_MAP                        0x81
+#define STK8BA50_ALL_CHANNEL_MASK              7
+#define STK8BA50_ALL_CHANNEL_SIZE              6
 
 #define STK8BA50_DRIVER_NAME                   "stk8ba50"
+#define STK8BA50_GPIO                          "stk8ba50_gpio"
+#define STK8BA50_IRQ_NAME                      "stk8ba50_event"
 
 #define STK8BA50_SCALE_AVAIL                   "0.0384 0.0767 0.1534 0.3069"
 
@@ -68,14 +82,29 @@ static const struct {
        {0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792}
 };
 
+/* Used to map scan mask bits to their corresponding channel register. */
+static const int stk8ba50_channel_table[] = {
+       STK8BA50_REG_XOUT,
+       STK8BA50_REG_YOUT,
+       STK8BA50_REG_ZOUT
+};
+
 struct stk8ba50_data {
        struct i2c_client *client;
        struct mutex lock;
        int range;
        u8 sample_rate_idx;
+       struct iio_trigger *dready_trig;
+       bool dready_trigger_on;
+       /*
+        * 3 x 16-bit channels (10-bit data, 6-bit padding) +
+        * 1 x 16 padding +
+        * 4 x 16 64-bit timestamp
+        */
+       s16 buffer[8];
 };
 
-#define STK8BA50_ACCEL_CHANNEL(reg, axis) {                            \
+#define STK8BA50_ACCEL_CHANNEL(index, reg, axis) {                     \
        .type = IIO_ACCEL,                                              \
        .address = reg,                                                 \
        .modified = 1,                                                  \
@@ -83,12 +112,21 @@ struct stk8ba50_data {
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),           \
                                    BIT(IIO_CHAN_INFO_SAMP_FREQ),       \
+       .scan_index = index,                                            \
+       .scan_type = {                                                  \
+               .sign = 's',                                            \
+               .realbits = 10,                                         \
+               .storagebits = 16,                                      \
+               .shift = STK8BA50_DATA_SHIFT,                           \
+               .endianness = IIO_CPU,                                  \
+       },                                                              \
 }
 
 static const struct iio_chan_spec stk8ba50_channels[] = {
-       STK8BA50_ACCEL_CHANNEL(STK8BA50_REG_XOUT, X),
-       STK8BA50_ACCEL_CHANNEL(STK8BA50_REG_YOUT, Y),
-       STK8BA50_ACCEL_CHANNEL(STK8BA50_REG_ZOUT, Z),
+       STK8BA50_ACCEL_CHANNEL(0, STK8BA50_REG_XOUT, X),
+       STK8BA50_ACCEL_CHANNEL(1, STK8BA50_REG_YOUT, Y),
+       STK8BA50_ACCEL_CHANNEL(2, STK8BA50_REG_ZOUT, Z),
+       IIO_CHAN_SOFT_TIMESTAMP(3),
 };
 
 static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL);
@@ -116,7 +154,61 @@ static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg)
                return ret;
        }
 
-       return sign_extend32(ret >> STK8BA50_DATA_SHIFT, 9);
+       return ret;
+}
+
+static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig,
+                                              bool state)
+{
+       struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+       struct stk8ba50_data *data = iio_priv(indio_dev);
+       int ret;
+
+       if (state)
+               ret = i2c_smbus_write_byte_data(data->client,
+                       STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
+       else
+               ret = i2c_smbus_write_byte_data(data->client,
+                       STK8BA50_REG_INTEN2, 0x00);
+
+       if (ret < 0)
+               dev_err(&data->client->dev, "failed to set trigger state\n");
+       else
+               data->dready_trigger_on = state;
+
+       return ret;
+}
+
+static const struct iio_trigger_ops stk8ba50_trigger_ops = {
+       .set_trigger_state = stk8ba50_data_rdy_trigger_set_state,
+       .owner = THIS_MODULE,
+};
+
+static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode)
+{
+       int ret;
+       u8 masked_reg;
+       struct i2c_client *client = data->client;
+
+       ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE);
+       if (ret < 0)
+               goto exit_err;
+
+       if (mode)
+               masked_reg = ret | STK8BA50_MODE_POWERBIT;
+       else
+               masked_reg = ret & (~STK8BA50_MODE_POWERBIT);
+
+       ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE,
+                                       masked_reg);
+       if (ret < 0)
+               goto exit_err;
+
+       return ret;
+
+exit_err:
+       dev_err(&client->dev, "failed to change sensor mode\n");
+       return ret;
 }
 
 static int stk8ba50_read_raw(struct iio_dev *indio_dev,
@@ -124,11 +216,26 @@ static int stk8ba50_read_raw(struct iio_dev *indio_dev,
                             int *val, int *val2, long mask)
 {
        struct stk8ba50_data *data = iio_priv(indio_dev);
+       int ret;
 
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
+               if (iio_buffer_enabled(indio_dev))
+                       return -EBUSY;
                mutex_lock(&data->lock);
-               *val = stk8ba50_read_accel(data, chan->address);
+               ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
+               if (ret < 0) {
+                       mutex_unlock(&data->lock);
+                       return -EINVAL;
+               }
+               ret = stk8ba50_read_accel(data, chan->address);
+               if (ret < 0) {
+                       stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
+                       mutex_unlock(&data->lock);
+                       return -EINVAL;
+               }
+               *val = sign_extend32(ret >> STK8BA50_DATA_SHIFT, 9);
+               stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
                mutex_unlock(&data->lock);
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
@@ -208,30 +315,100 @@ static const struct iio_info stk8ba50_info = {
        .attrs                  = &stk8ba50_attribute_group,
 };
 
-static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode)
+static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
+{
+       struct iio_poll_func *pf = p;
+       struct iio_dev *indio_dev = pf->indio_dev;
+       struct stk8ba50_data *data = iio_priv(indio_dev);
+       int bit, ret, i = 0;
+
+       mutex_lock(&data->lock);
+       /*
+        * Do a bulk read if all channels are requested,
+        * from 0x02 (XOUT1) to 0x07 (ZOUT2)
+        */
+       if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) {
+               ret = i2c_smbus_read_i2c_block_data(data->client,
+                                                   STK8BA50_REG_XOUT,
+                                                   STK8BA50_ALL_CHANNEL_SIZE,
+                                                   (u8 *)data->buffer);
+               if (ret < STK8BA50_ALL_CHANNEL_SIZE) {
+                       dev_err(&data->client->dev, "register read failed\n");
+                       goto err;
+               }
+       } else {
+               for_each_set_bit(bit, indio_dev->active_scan_mask,
+                                indio_dev->masklength) {
+                       ret = stk8ba50_read_accel(data,
+                                                 stk8ba50_channel_table[bit]);
+                       if (ret < 0)
+                               goto err;
+
+                       data->buffer[i++] = ret;
+               }
+       }
+       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 irqreturn_t stk8ba50_data_rdy_trig_poll(int irq, void *private)
 {
+       struct iio_dev *indio_dev = private;
+       struct stk8ba50_data *data = iio_priv(indio_dev);
+
+       if (data->dready_trigger_on)
+               iio_trigger_poll(data->dready_trig);
+
+       return IRQ_HANDLED;
+}
+
+static int stk8ba50_buffer_preenable(struct iio_dev *indio_dev)
+{
+       struct stk8ba50_data *data = iio_priv(indio_dev);
+
+       return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
+}
+
+static int stk8ba50_buffer_postdisable(struct iio_dev *indio_dev)
+{
+       struct stk8ba50_data *data = iio_priv(indio_dev);
+
+       return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
+}
+
+static const struct iio_buffer_setup_ops stk8ba50_buffer_setup_ops = {
+       .preenable   = stk8ba50_buffer_preenable,
+       .postenable  = iio_triggered_buffer_postenable,
+       .predisable  = iio_triggered_buffer_predisable,
+       .postdisable = stk8ba50_buffer_postdisable,
+};
+
+static int stk8ba50_gpio_probe(struct i2c_client *client)
+{
+       struct device *dev;
+       struct gpio_desc *gpio;
        int ret;
-       u8 masked_reg;
-       struct i2c_client *client = data->client;
 
-       ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE);
-       if (ret < 0)
-               goto exit_err;
+       if (!client)
+               return -EINVAL;
 
-       if (mode)
-               masked_reg = ret | STK8BA50_MODE_POWERBIT;
-       else
-               masked_reg = ret & (~STK8BA50_MODE_POWERBIT);
+       dev = &client->dev;
 
-       ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE,
-                                       masked_reg);
-       if (ret < 0)
-               goto exit_err;
+       /* data ready gpio interrupt pin */
+       gpio = devm_gpiod_get_index(dev, STK8BA50_GPIO, 0, GPIOD_IN);
+       if (IS_ERR(gpio)) {
+               dev_err(dev, "acpi gpio get index failed\n");
+               return PTR_ERR(gpio);
+       }
 
-       return ret;
+       ret = gpiod_to_irq(gpio);
+       dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
 
-exit_err:
-       dev_err(&client->dev, "failed to change sensor mode\n");
        return ret;
 }
 
@@ -274,14 +451,78 @@ static int stk8ba50_probe(struct i2c_client *client,
        /* The default sampling rate is 1792 Hz (maximum) */
        data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX;
 
+       /* Set up interrupts */
+       ret = i2c_smbus_write_byte_data(client,
+                       STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
+       if (ret < 0) {
+               dev_err(&client->dev, "failed to set up interrupts\n");
+               goto err_power_off;
+       }
+       ret = i2c_smbus_write_byte_data(client,
+                       STK8BA50_REG_INTMAP2, STK8BA50_DREADY_INT_MAP);
+       if (ret < 0) {
+               dev_err(&client->dev, "failed to set up interrupts\n");
+               goto err_power_off;
+       }
+
+       if (client->irq < 0)
+               client->irq = stk8ba50_gpio_probe(client);
+
+       if (client->irq >= 0) {
+               ret = devm_request_threaded_irq(&client->dev, client->irq,
+                                               stk8ba50_data_rdy_trig_poll,
+                                               NULL,
+                                               IRQF_TRIGGER_RISING |
+                                               IRQF_ONESHOT,
+                                               STK8BA50_IRQ_NAME,
+                                               indio_dev);
+               if (ret < 0) {
+                       dev_err(&client->dev, "request irq %d failed\n",
+                               client->irq);
+                       goto err_power_off;
+               }
+
+               data->dready_trig = devm_iio_trigger_alloc(&client->dev,
+                                                          "%s-dev%d",
+                                                          indio_dev->name,
+                                                          indio_dev->id);
+               if (!data->dready_trig) {
+                       ret = -ENOMEM;
+                       goto err_power_off;
+               }
+
+               data->dready_trig->dev.parent = &client->dev;
+               data->dready_trig->ops = &stk8ba50_trigger_ops;
+               iio_trigger_set_drvdata(data->dready_trig, indio_dev);
+               ret = iio_trigger_register(data->dready_trig);
+               if (ret) {
+                       dev_err(&client->dev, "iio trigger register failed\n");
+                       goto err_power_off;
+               }
+       }
+
+       ret = iio_triggered_buffer_setup(indio_dev,
+                                        iio_pollfunc_store_time,
+                                        stk8ba50_trigger_handler,
+                                        &stk8ba50_buffer_setup_ops);
+       if (ret < 0) {
+               dev_err(&client->dev, "iio triggered buffer setup failed\n");
+               goto err_trigger_unregister;
+       }
+
        ret = iio_device_register(indio_dev);
        if (ret < 0) {
                dev_err(&client->dev, "device_register failed\n");
-               goto err_power_off;
+               goto err_buffer_cleanup;
        }
 
        return ret;
 
+err_buffer_cleanup:
+       iio_triggered_buffer_cleanup(indio_dev);
+err_trigger_unregister:
+       if (data->dready_trig)
+               iio_trigger_unregister(data->dready_trig);
 err_power_off:
        stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
        return ret;
@@ -290,10 +531,15 @@ err_power_off:
 static int stk8ba50_remove(struct i2c_client *client)
 {
        struct iio_dev *indio_dev = i2c_get_clientdata(client);
+       struct stk8ba50_data *data = iio_priv(indio_dev);
 
        iio_device_unregister(indio_dev);
+       iio_triggered_buffer_cleanup(indio_dev);
+
+       if (data->dready_trig)
+               iio_trigger_unregister(data->dready_trig);
 
-       return stk8ba50_set_power(iio_priv(indio_dev), STK8BA50_MODE_SUSPEND);
+       return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
 }
 
 #ifdef CONFIG_PM_SLEEP