iio: mxc4005: add data ready trigger for mxc4005

Add iio trigger for the data ready interrupt that signals new
measurements for the X, Y and Z axes.

Signed-off-by: Teodora Baluta <teodora.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c
index 390eaf8..e72e218 100644 (file)
--- a/drivers/iio/accel/mxc4005.c
+++ b/drivers/iio/accel/mxc4005.c
@@ -17,13 +17,16 @@
 #include <linux/i2c.h>
 #include <linux/iio/iio.h>
 #include <linux/acpi.h>
+#include <linux/gpio/consumer.h>
 #include <linux/regmap.h>
 #include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/iio/trigger_consumer.h>
 
 #define MXC4005_DRV_NAME               "mxc4005"
+#define MXC4005_IRQ_NAME               "mxc4005_event"
 #define MXC4005_REGMAP_NAME            "mxc4005_regmap"
 
 #define MXC4005_REG_XOUT_UPPER         0x03
@@ -33,6 +36,12 @@
 #define MXC4005_REG_ZOUT_UPPER         0x07
 #define MXC4005_REG_ZOUT_LOWER         0x08
 
+#define MXC4005_REG_INT_MASK1          0x0B
+#define MXC4005_REG_INT_MASK1_BIT_DRDYE        0x01
+
+#define MXC4005_REG_INT_CLR1           0x01
+#define MXC4005_REG_INT_CLR1_BIT_DRDYC 0x01
+
 #define MXC4005_REG_CONTROL            0x0D
 #define MXC4005_REG_CONTROL_MASK_FSR   GENMASK(6, 5)
 #define MXC4005_CONTROL_FSR_SHIFT      5
@@ -55,7 +64,9 @@ struct mxc4005_data {
        struct device *dev;
        struct mutex mutex;
        struct regmap *regmap;
+       struct iio_trigger *dready_trig;
        __be16 buffer[8];
+       bool trigger_enabled;
 };
 
 /*
@@ -107,6 +118,8 @@ static bool mxc4005_is_readable_reg(struct device *dev, unsigned int reg)
 static bool mxc4005_is_writeable_reg(struct device *dev, unsigned int reg)
 {
        switch (reg) {
+       case MXC4005_REG_INT_CLR1:
+       case MXC4005_REG_INT_MASK1:
        case MXC4005_REG_CONTROL:
                return true;
        default:
@@ -307,6 +320,91 @@ err:
        return IRQ_HANDLED;
 }
 
+static int mxc4005_clr_intr(struct mxc4005_data *data)
+{
+       int ret;
+
+       /* clear interrupt */
+       ret = regmap_write(data->regmap, MXC4005_REG_INT_CLR1,
+                          MXC4005_REG_INT_CLR1_BIT_DRDYC);
+       if (ret < 0) {
+               dev_err(data->dev, "failed to write to reg_int_clr1\n");
+               return ret;
+       }
+
+       return 0;
+}
+
+static int mxc4005_set_trigger_state(struct iio_trigger *trig,
+                                    bool state)
+{
+       struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+       struct mxc4005_data *data = iio_priv(indio_dev);
+       int ret;
+
+       mutex_lock(&data->mutex);
+       if (state) {
+               ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1,
+                                  MXC4005_REG_INT_MASK1_BIT_DRDYE);
+       } else {
+               ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1,
+                                  ~MXC4005_REG_INT_MASK1_BIT_DRDYE);
+       }
+
+       if (ret < 0) {
+               mutex_unlock(&data->mutex);
+               dev_err(data->dev, "failed to update reg_int_mask1");
+               return ret;
+       }
+
+       data->trigger_enabled = state;
+       mutex_unlock(&data->mutex);
+
+       return 0;
+}
+
+static int mxc4005_trigger_try_reen(struct iio_trigger *trig)
+{
+       struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+       struct mxc4005_data *data = iio_priv(indio_dev);
+
+       if (!data->dready_trig)
+               return 0;
+
+       return mxc4005_clr_intr(data);
+}
+
+static const struct iio_trigger_ops mxc4005_trigger_ops = {
+       .set_trigger_state = mxc4005_set_trigger_state,
+       .try_reenable = mxc4005_trigger_try_reen,
+       .owner = THIS_MODULE,
+};
+
+static int mxc4005_gpio_probe(struct i2c_client *client,
+                             struct mxc4005_data *data)
+{
+       struct device *dev;
+       struct gpio_desc *gpio;
+       int ret;
+
+       if (!client)
+               return -EINVAL;
+
+       dev = &client->dev;
+
+       gpio = devm_gpiod_get_index(dev, "mxc4005_int", 0, GPIOD_IN);
+       if (IS_ERR(gpio)) {
+               dev_err(dev, "failed to get acpi gpio index\n");
+               return PTR_ERR(gpio);
+       }
+
+       ret = gpiod_to_irq(gpio);
+
+       dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
+
+       return ret;
+}
+
 static int mxc4005_chip_init(struct mxc4005_data *data)
 {
        int ret;
@@ -363,7 +461,7 @@ static int mxc4005_probe(struct i2c_client *client,
        indio_dev->info = &mxc4005_info;
 
        ret = iio_triggered_buffer_setup(indio_dev,
-                                        &iio_pollfunc_store_time,
+                                        iio_pollfunc_store_time,
                                         mxc4005_trigger_handler,
                                         NULL);
        if (ret < 0) {
@@ -372,6 +470,43 @@ static int mxc4005_probe(struct i2c_client *client,
                return ret;
        }
 
+       if (client->irq < 0)
+               client->irq = mxc4005_gpio_probe(client, data);
+
+       if (client->irq > 0) {
+               data->dready_trig = devm_iio_trigger_alloc(&client->dev,
+                                                          "%s-dev%d",
+                                                          indio_dev->name,
+                                                          indio_dev->id);
+               if (!data->dready_trig)
+                       return -ENOMEM;
+
+               ret = devm_request_threaded_irq(&client->dev, client->irq,
+                                               iio_trigger_generic_data_rdy_poll,
+                                               NULL,
+                                               IRQF_TRIGGER_FALLING |
+                                               IRQF_ONESHOT,
+                                               MXC4005_IRQ_NAME,
+                                               data->dready_trig);
+               if (ret) {
+                       dev_err(&client->dev,
+                               "failed to init threaded irq\n");
+                       goto err_buffer_cleanup;
+               }
+
+               data->dready_trig->dev.parent = &client->dev;
+               data->dready_trig->ops = &mxc4005_trigger_ops;
+               iio_trigger_set_drvdata(data->dready_trig, indio_dev);
+               indio_dev->trig = data->dready_trig;
+               iio_trigger_get(indio_dev->trig);
+               ret = iio_trigger_register(data->dready_trig);
+               if (ret) {
+                       dev_err(&client->dev,
+                               "failed to register trigger\n");
+                       goto err_trigger_unregister;
+               }
+       }
+
        ret = iio_device_register(indio_dev);
        if (ret < 0) {
                dev_err(&client->dev,
@@ -381,6 +516,8 @@ static int mxc4005_probe(struct i2c_client *client,
 
        return 0;
 
+err_trigger_unregister:
+       iio_trigger_unregister(data->dready_trig);
 err_buffer_cleanup:
        iio_triggered_buffer_cleanup(indio_dev);
 
@@ -390,10 +527,13 @@ err_buffer_cleanup:
 static int mxc4005_remove(struct i2c_client *client)
 {
        struct iio_dev *indio_dev = i2c_get_clientdata(client);
+       struct mxc4005_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 0;
 }