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>

1 files changed, 141 insertions, 1 deletions

diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c
index 390eaf8cb2f8..e72e218c2696 100644
--- 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;
 }