[PATCH v2 3/3] iio: mxc4005: add data ready trigger for mxc4005

From: Teodora Baluta
Date: Thu Aug 13 2015 - 13:32:17 EST

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@xxxxxxxxx>
---
drivers/iio/accel/mxc4005.c | 159 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 158 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c
index 5f4813d..0c47bfe 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 +36,15 @@
#define MXC4005_REG_ZOUT_UPPER 0x07
#define MXC4005_REG_ZOUT_LOWER 0x08

+#define MXC4005_REG_INT_SRC1 0x01
+#define MXC4005_REG_INT_SRC2_BIT_DRDY 0x01
+
+#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 +67,10 @@ struct mxc4005_data {
struct i2c_client *client;
struct mutex mutex;
struct regmap *regmap;
+ struct iio_trigger *dready_trig;
+ int64_t timestamp;
__be16 buffer[3];
+ bool trigger_enabled;
};

/*
@@ -97,6 +112,7 @@ static bool mxc4005_is_readable_reg(struct device *dev, unsigned int reg)
case MXC4005_REG_ZOUT_UPPER:
case MXC4005_REG_ZOUT_LOWER:
case MXC4005_REG_DEVICE_ID:
+ case MXC4005_REG_INT_SRC1:
case MXC4005_REG_CONTROL:
return true;
default:
@@ -107,6 +123,8 @@ 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:
@@ -300,7 +318,7 @@ static irqreturn_t mxc4005_trigger_handler(int irq, void *private)
goto err;

iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
- iio_get_time_ns());
+ data->timestamp);

err:
iio_trigger_notify_done(indio_dev->trig);
@@ -308,6 +326,103 @@ err:
return IRQ_HANDLED;
}

+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->client->dev,
+ "failed to update reg_int_mask1");
+ return ret;
+ }
+
+ data->trigger_enabled = state;
+ mutex_unlock(&data->mutex);
+
+ return 0;
+}
+
+static const struct iio_trigger_ops mxc4005_trigger_ops = {
+ .set_trigger_state = mxc4005_set_trigger_state,
+ .owner = THIS_MODULE,
+};
+
+static irqreturn_t mxc4005_irq_thrd_handler(int irq, void *private)
+{
+ struct iio_dev *indio_dev = private;
+ struct mxc4005_data *data = iio_priv(indio_dev);
+ unsigned int reg;
+ int ret;
+
+ ret = regmap_read(data->regmap, MXC4005_REG_INT_SRC1, &reg);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "failed to read reg_int_src1\n");
+ goto exit;
+ }
+
+ /* clear interrupt */
+ ret = regmap_write(data->regmap, MXC4005_REG_INT_CLR1,
+ MXC4005_REG_INT_CLR1_BIT_DRDYC);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "failed to write to reg_int_clr1\n");
+ goto exit;
+ }
+
+exit:
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t mxc4005_irq_handler(int irq, void *private)
+{
+ struct iio_dev *indio_dev = private;
+ struct mxc4005_data *data = iio_priv(indio_dev);
+
+ data->timestamp = iio_get_time_ns();
+
+ if (data->trigger_enabled)
+ iio_trigger_poll(data->dready_trig);
+
+ return IRQ_WAKE_THREAD;
+}
+
+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;
@@ -373,6 +488,43 @@ 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) {
+ ret = devm_request_threaded_irq(&client->dev, client->irq,
+ mxc4005_irq_handler,
+ mxc4005_irq_thrd_handler,
+ IRQF_TRIGGER_FALLING |
+ IRQF_ONESHOT,
+ MXC4005_IRQ_NAME,
+ indio_dev);
+ if (ret) {
+ dev_err(&client->dev,
+ "failed to init threaded irq\n");
+ goto err_buffer_cleanup;
+ }
+
+ data->dready_trig = devm_iio_trigger_alloc(&client->dev,
+ "%s-dev%d",
+ indio_dev->name,
+ indio_dev->id);
+ if (!data->dready_trig)
+ return -ENOMEM;
+
+ 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,
@@ -382,6 +534,8 @@ 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);

@@ -391,10 +545,13 @@ 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;
}
--
1.9.1

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