[PATCH 0/3] iio: accel: add support for Memsic MXC4005

[PATCH 0/3] iio: accel: add support for Memsic MXC4005

[Teodora Baluta]

This patch set adds support for Memsic MXC4005XC 3-axis accelerometer
sensor. The first patch adds basic support for the accelerometer, with
raw readings, the second patch adds support for buffer mode and the last
one adds the data ready trigger.

Teodora Baluta (3):
  iio: accel: add support for mxc4005 accelerometer
  iio: mxc4005: add triggered buffer mode for mxc4005
  iio: mxc4005: add data ready trigger for mxc4005

 drivers/iio/accel/Kconfig   |  13 +
 drivers/iio/accel/Makefile  |   2 +
 drivers/iio/accel/mxc4005.c | 601 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 616 insertions(+)
 create mode 100644 drivers/iio/accel/mxc4005.c

-- 
1.9.1

[PATCH 1/3] iio: accel: add support for mxc4005 accelerometer

[Teodora Baluta]

This patch adds support for Memsic MXC4005XC 3-axis accelerometer. The
current implementation is a minimal one as it adds raw readings for the
three axes and setting scale from userspace.

Signed-off-by: Teodora Baluta <teodora.baluta@intel.com>
---
 drivers/iio/accel/Kconfig   |  11 ++
 drivers/iio/accel/Makefile  |   2 +
 drivers/iio/accel/mxc4005.c | 373 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 386 insertions(+)
 create mode 100644 drivers/iio/accel/mxc4005.c

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 00e7bcb..7f534a3 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -137,6 +137,17 @@ config MMA9553
 	  To compile this driver as a module, choose M here: the module
 	  will be called mma9553.
 
+config MXC4005
+	tristate "Memsic MXC4005XC 3-Axis Accelerometer Driver"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  Say yes here to build support for the Memsic MXC4005XC 3-axis
+	  accelerometer.
+
+	  To compile this driver as a module, choose M. The module will be
+	  called mxc4005.
+
 config STK8312
 	tristate "Sensortek STK8312 3-Axis Accelerometer Driver"
 	depends on I2C
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index ebd2675..020dda0 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -14,6 +14,8 @@ obj-$(CONFIG_MMA9551_CORE)	+= mma9551_core.o
 obj-$(CONFIG_MMA9551)		+= mma9551.o
 obj-$(CONFIG_MMA9553)		+= mma9553.o
 
+obj-$(CONFIG_MXC4005)		+= mxc4005.o
+
 obj-$(CONFIG_STK8312)		+= stk8312.o
 obj-$(CONFIG_STK8BA50)		+= stk8ba50.o
 
diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c
new file mode 100644
index 0000000..0f0410c
--- /dev/null
+++ b/drivers/iio/accel/mxc4005.c
@@ -0,0 +1,373 @@
+/*
+ * 3-axis accelerometer driver for MXC4005XC Memsic sensor
+ *
+ * Copyright (c) 2014, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/acpi.h>
+#include <linux/regmap.h>
+#include <linux/iio/sysfs.h>
+
+#define MXC4005_DRV_NAME		"mxc4005"
+#define MXC4005_REGMAP_NAME		"mxc4005_regmap"
+
+#define MXC4005_REG_XOUT_UPPER		0x03
+#define MXC4005_REG_XOUT_LOWER		0x04
+#define MXC4005_REG_YOUT_UPPER		0x05
+#define MXC4005_REG_YOUT_LOWER		0x06
+#define MXC4005_REG_ZOUT_UPPER		0x07
+#define MXC4005_REG_ZOUT_LOWER		0x08
+
+#define MXC4005_REG_CONTROL		0x0D
+#define MXC4005_REG_CONTROL_MASK_FSR	GENMASK(6, 5)
+#define MXC4005_CONTROL_FSR_SHIFT	5
+
+#define MXC4005_REG_DEVICE_ID		0x0E
+
+#define MXC4005_AXIS_TO_REG(axis)	(MXC4005_REG_XOUT_UPPER + (axis * 2))
+
+enum mxc4005_axis {
+	AXIS_X,
+	AXIS_Y,
+	AXIS_Z,
+};
+
+enum mxc4005_range {
+	MXC4005_RANGE_2G,
+	MXC4005_RANGE_4G,
+	MXC4005_RANGE_8G,
+};
+
+struct mxc4005_data {
+	struct i2c_client *client;
+	struct mutex mutex;
+	struct regmap *regmap;
+};
+
+/*
+ * MXC4005 can operate in the following ranges:
+ * +/- 2G, 4G, 8G (the default +/-2G)
+ *
+ * (2 + 2) * 9.81 / (2^12 - 1) = 0.009582
+ * (4 + 4) * 9.81 / (2^12 - 1) = 0.019164
+ * (8 + 8) * 9.81 / (2^12 - 1) = 0.038329
+ */
+static const struct {
+	u8 range;
+	u16 scale;
+} mxc4005_scale_table[] = {
+	{MXC4005_RANGE_2G, 9582},
+	{MXC4005_RANGE_4G, 19164},
+	{MXC4005_RANGE_8G, 38329},
+};
+
+
+static IIO_CONST_ATTR(in_accel_scale_available, "0.009582 0.019164 0.038329");
+
+static struct attribute *mxc4005_attributes[] = {
+	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group mxc4005_attrs_group = {
+	.attrs = mxc4005_attributes,
+};
+
+static bool mxc4005_is_readable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case MXC4005_REG_XOUT_UPPER:
+	case MXC4005_REG_XOUT_LOWER:
+	case MXC4005_REG_YOUT_UPPER:
+	case MXC4005_REG_YOUT_LOWER:
+	case MXC4005_REG_ZOUT_UPPER:
+	case MXC4005_REG_ZOUT_LOWER:
+	case MXC4005_REG_DEVICE_ID:
+	case MXC4005_REG_CONTROL:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool mxc4005_is_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case MXC4005_REG_CONTROL:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config mxc4005_regmap_config = {
+	.name = MXC4005_DRV_NAME,
+
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = MXC4005_REG_DEVICE_ID,
+	.cache_type = REGCACHE_NONE,
+
+	.readable_reg = mxc4005_is_readable_reg,
+	.writeable_reg = mxc4005_is_writeable_reg,
+};
+
+static int mxc4005_read_axis(struct mxc4005_data *data,
+			     int axis)
+{
+	u16 reg;
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, MXC4005_AXIS_TO_REG(axis),
+			       (u8 *) &reg, 2);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "failed to read axis %d\n", axis);
+		return ret;
+	}
+
+	return reg;
+}
+
+static int mxc4005_read_scale(struct mxc4005_data *data)
+{
+	unsigned int reg;
+	int ret;
+	int i;
+
+	ret = regmap_read(data->regmap, MXC4005_REG_CONTROL, &reg);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "failed to read reg_control");
+		return ret;
+	}
+
+	i = reg >> MXC4005_CONTROL_FSR_SHIFT;
+
+	if (i < 0 || i >= ARRAY_SIZE(mxc4005_scale_table))
+		return -EINVAL;
+
+	return mxc4005_scale_table[i].scale;
+}
+
+static int mxc4005_set_scale(struct mxc4005_data *data, int val)
+{
+	int i;
+	int ret;
+	int scale;
+
+	for (i = 0; i < ARRAY_SIZE(mxc4005_scale_table); i++) {
+		if (mxc4005_scale_table[i].scale == val) {
+			scale = i << MXC4005_CONTROL_FSR_SHIFT;
+			ret = regmap_update_bits(data->regmap,
+						 MXC4005_REG_CONTROL,
+						 MXC4005_REG_CONTROL_MASK_FSR,
+						 scale);
+			if (ret < 0)
+				dev_err(&data->client->dev,
+					"failed to write reg_control %d\n",
+					ret);
+			return ret;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int mxc4005_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	struct mxc4005_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_ACCEL:
+			if (iio_buffer_enabled(indio_dev))
+				return -EBUSY;
+
+			mutex_lock(&data->mutex);
+			ret = mxc4005_read_axis(data, chan->address);
+			mutex_unlock(&data->mutex);
+			if (ret < 0)
+				return ret;
+			ret = be16_to_cpu(ret);
+			*val = sign_extend32(ret >> 4, 11);
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		mutex_lock(&data->mutex);
+		ret = mxc4005_read_scale(data);
+		mutex_unlock(&data->mutex);
+		if (ret < 0)
+			return ret;
+
+		*val2 = ret;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int mxc4005_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int val, int val2, long mask)
+{
+	struct mxc4005_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		if (val != 0)
+			return -EINVAL;
+
+		mutex_lock(&data->mutex);
+		ret = mxc4005_set_scale(data, val2);
+		mutex_unlock(&data->mutex);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static const struct iio_info mxc4005_info = {
+	.driver_module	= THIS_MODULE,
+	.read_raw	= mxc4005_read_raw,
+	.write_raw	= mxc4005_write_raw,
+	.attrs		= &mxc4005_attrs_group,
+};
+
+#define MXC4005_CHANNEL(_axis) {				\
+	.type = IIO_ACCEL,					\
+	.modified = 1,						\
+	.channel2 = IIO_MOD_##_axis,				\
+	.address = AXIS_##_axis,				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+}
+
+static const struct iio_chan_spec mxc4005_channels[] = {
+	MXC4005_CHANNEL(X),
+	MXC4005_CHANNEL(Y),
+	MXC4005_CHANNEL(Z),
+};
+
+static int mxc4005_chip_init(struct mxc4005_data *data)
+{
+	int ret;
+	unsigned int reg;
+
+	ret = regmap_read(data->regmap, MXC4005_REG_DEVICE_ID, &reg);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "failed to read chip id\n");
+		return ret;
+	}
+
+	dev_dbg(&data->client->dev, "MXC4005 chip id %d\n", reg);
+
+	return 0;
+}
+
+static int mxc4005_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct mxc4005_data *data;
+	struct iio_dev *indio_dev;
+	struct regmap *regmap;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	regmap = devm_regmap_init_i2c(client, &mxc4005_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "failed to initialize regmap\n");
+		return PTR_ERR(regmap);
+	}
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+	data->regmap = regmap;
+
+	ret = mxc4005_chip_init(data);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to init chip\n");
+		return ret;
+	}
+
+	mutex_init(&data->mutex);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->channels = mxc4005_channels;
+	indio_dev->num_channels = ARRAY_SIZE(mxc4005_channels);
+	indio_dev->name = MXC4005_DRV_NAME;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &mxc4005_info;
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(&client->dev,
+			"unable to register iio device %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int mxc4005_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+	iio_device_unregister(indio_dev);
+
+	return 0;
+}
+
+static const struct acpi_device_id mxc4005_acpi_match[] = {
+	{"MXC4005",	0},
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, mxc4005_acpi_match);
+
+static const struct i2c_device_id mxc4005_id[] = {
+	{"mxc4005",	0},
+	{ },
+};
+
+MODULE_DEVICE_TABLE(i2c, mxc4005_id);
+
+static struct i2c_driver mxc4005_driver = {
+	.driver = {
+		.name = MXC4005_DRV_NAME,
+		.acpi_match_table = ACPI_PTR(mxc4005_acpi_match),
+	},
+	.probe		= mxc4005_probe,
+	.remove		= mxc4005_remove,
+	.id_table	= mxc4005_id,
+};
+
+module_i2c_driver(mxc4005_driver);
+
+MODULE_AUTHOR("Teodora Baluta <teodora.baluta@intel.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MXC4005 3-axis accelerometer driver");
-- 
1.9.1

[PATCH 2/3] iio: mxc4005: add triggered buffer mode for mxc4005

[Teodora Baluta]

This patch adds support for buffered readings for the 3-axis
accelerometer mxc4005.

Signed-off-by: Teodora Baluta <teodora.baluta@intel.com>
---
 drivers/iio/accel/Kconfig   |  2 ++
 drivers/iio/accel/mxc4005.c | 75 ++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 73 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 7f534a3..e8d135e 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -140,6 +140,8 @@ config MMA9553
 config MXC4005
 	tristate "Memsic MXC4005XC 3-Axis Accelerometer Driver"
 	depends on I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
 	select REGMAP_I2C
 	help
 	  Say yes here to build support for the Memsic MXC4005XC 3-axis
diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c
index 0f0410c..114c14d 100644
--- a/drivers/iio/accel/mxc4005.c
+++ b/drivers/iio/accel/mxc4005.c
@@ -19,6 +19,9 @@
 #include <linux/acpi.h>
 #include <linux/regmap.h>
 #include <linux/iio/sysfs.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_REGMAP_NAME		"mxc4005_regmap"
@@ -54,6 +57,7 @@ struct mxc4005_data {
 	struct i2c_client *client;
 	struct mutex mutex;
 	struct regmap *regmap;
+	s16 buffer[8];
 };
 
 /*
@@ -125,6 +129,20 @@ static const struct regmap_config mxc4005_regmap_config = {
 	.writeable_reg = mxc4005_is_writeable_reg,
 };
 
+static int mxc4005_read_xyz(struct mxc4005_data *data)
+{
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, MXC4005_REG_XOUT_UPPER,
+			       (u8 *) data->buffer, sizeof(data->buffer));
+	if (ret < 0) {
+		dev_err(&data->client->dev, "failed to read axes\n");
+		return ret;
+	}
+
+	return 0;
+}
+
 static int mxc4005_read_axis(struct mxc4005_data *data,
 			     int axis)
 {
@@ -190,6 +208,7 @@ static int mxc4005_read_raw(struct iio_dev *indio_dev,
 			    int *val, int *val2, long mask)
 {
 	struct mxc4005_data *data = iio_priv(indio_dev);
+	int axis = chan->scan_index;
 	int ret;
 
 	switch (mask) {
@@ -200,12 +219,13 @@ static int mxc4005_read_raw(struct iio_dev *indio_dev,
 				return -EBUSY;
 
 			mutex_lock(&data->mutex);
-			ret = mxc4005_read_axis(data, chan->address);
+			ret = mxc4005_read_axis(data, axis);
 			mutex_unlock(&data->mutex);
 			if (ret < 0)
 				return ret;
 			ret = be16_to_cpu(ret);
-			*val = sign_extend32(ret >> 4, 11);
+			*val = sign_extend32(ret >> chan->scan_type.shift,
+					     chan->scan_type.realbits - 1);
 			return IIO_VAL_INT;
 		default:
 			return -EINVAL;
@@ -259,17 +279,47 @@ static const struct iio_info mxc4005_info = {
 	.type = IIO_ACCEL,					\
 	.modified = 1,						\
 	.channel2 = IIO_MOD_##_axis,				\
-	.address = AXIS_##_axis,				\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+	.scan_index = AXIS_##_axis,				\
+	.scan_type = {						\
+		.sign = 's',					\
+		.realbits = 12,					\
+		.storagebits = 16,				\
+		.shift = 4,					\
+		.endianness = IIO_BE,				\
+	},							\
 }
 
 static const struct iio_chan_spec mxc4005_channels[] = {
 	MXC4005_CHANNEL(X),
 	MXC4005_CHANNEL(Y),
 	MXC4005_CHANNEL(Z),
+	IIO_CHAN_SOFT_TIMESTAMP(3),
 };
 
+static irqreturn_t mxc4005_trigger_handler(int irq, void *private)
+{
+	struct iio_poll_func *pf = private;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct mxc4005_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->mutex);
+	ret = mxc4005_read_xyz(data);
+	mutex_unlock(&data->mutex);
+	if (ret < 0)
+		goto err;
+
+	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+					   iio_get_time_ns());
+
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
 static int mxc4005_chip_init(struct mxc4005_data *data)
 {
 	int ret;
@@ -324,14 +374,29 @@ static int mxc4005_probe(struct i2c_client *client,
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &mxc4005_info;
 
+	ret = iio_triggered_buffer_setup(indio_dev,
+					 &iio_pollfunc_store_time,
+					 mxc4005_trigger_handler,
+					 NULL);
+	if (ret < 0) {
+		dev_err(&client->dev,
+			"failed to setup iio triggered buffer\n");
+		return ret;
+	}
+
 	ret = iio_device_register(indio_dev);
 	if (ret < 0) {
 		dev_err(&client->dev,
 			"unable to register iio device %d\n", ret);
-		return ret;
+		goto err_buffer_cleanup;
 	}
 
 	return 0;
+
+err_buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+
+	return ret;
 }
 
 static int mxc4005_remove(struct i2c_client *client)
@@ -340,6 +405,8 @@ static int mxc4005_remove(struct i2c_client *client)
 
 	iio_device_unregister(indio_dev);
 
+	iio_triggered_buffer_cleanup(indio_dev);
+
 	return 0;
 }
 
-- 
1.9.1

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

[Teodora Baluta]

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>
---
 drivers/iio/accel/mxc4005.c | 163 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 162 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c
index 114c14d..1127eca 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
@@ -57,7 +69,10 @@ struct mxc4005_data {
 	struct i2c_client *client;
 	struct mutex mutex;
 	struct regmap *regmap;
+	struct iio_trigger *dready_trig;
+	int64_t timestamp;
 	s16 buffer[8];
+	bool trigger_enabled;
 };
 
 /*
@@ -99,6 +114,7 @@ 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:
@@ -109,6 +125,8 @@ 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:
@@ -312,7 +330,7 @@ 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);
@@ -320,6 +338,106 @@ 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);
+	}
+	mutex_unlock(&data->mutex);
+
+	if (ret < 0) {
+		dev_err(&data->client->dev,
+			"failed to update reg_int_mask1");
+		return ret;
+	}
+
+	data->trigger_enabled = state;
+
+	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;
+
+	mutex_lock(&data->mutex);
+	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:
+	mutex_unlock(&data->mutex);
+
+	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;
@@ -384,6 +502,43 @@ 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,
@@ -393,6 +548,8 @@ 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);
 
@@ -402,10 +559,14 @@ 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

Re: [PATCH 1/3] iio: accel: add support for mxc4005 accelerometer

[Peter Meerwald]

On Fri, 31 Jul 2015, Teodora Baluta wrote:

> This patch adds support for Memsic MXC4005XC 3-axis accelerometer. The
> current implementation is a minimal one as it adds raw readings for the
> three axes and setting scale from userspace.

some comments below
 
> Signed-off-by: Teodora Baluta <teodora.baluta@intel.com>
> ---
>  drivers/iio/accel/Kconfig   |  11 ++
>  drivers/iio/accel/Makefile  |   2 +
>  drivers/iio/accel/mxc4005.c | 373 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 386 insertions(+)
>  create mode 100644 drivers/iio/accel/mxc4005.c
> 
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index 00e7bcb..7f534a3 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -137,6 +137,17 @@ config MMA9553
>  	  To compile this driver as a module, choose M here: the module
>  	  will be called mma9553.
>  
> +config MXC4005
> +	tristate "Memsic MXC4005XC 3-Axis Accelerometer Driver"
> +	depends on I2C
> +	select REGMAP_I2C
> +	help
> +	  Say yes here to build support for the Memsic MXC4005XC 3-axis
> +	  accelerometer.
> +
> +	  To compile this driver as a module, choose M. The module will be
> +	  called mxc4005.
> +
>  config STK8312
>  	tristate "Sensortek STK8312 3-Axis Accelerometer Driver"
>  	depends on I2C
> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
> index ebd2675..020dda0 100644
> --- a/drivers/iio/accel/Makefile
> +++ b/drivers/iio/accel/Makefile
> @@ -14,6 +14,8 @@ obj-$(CONFIG_MMA9551_CORE)	+= mma9551_core.o
>  obj-$(CONFIG_MMA9551)		+= mma9551.o
>  obj-$(CONFIG_MMA9553)		+= mma9553.o
>  
> +obj-$(CONFIG_MXC4005)		+= mxc4005.o
> +
>  obj-$(CONFIG_STK8312)		+= stk8312.o
>  obj-$(CONFIG_STK8BA50)		+= stk8ba50.o
>  
> diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c
> new file mode 100644
> index 0000000..0f0410c
> --- /dev/null
> +++ b/drivers/iio/accel/mxc4005.c
> @@ -0,0 +1,373 @@
> +/*
> + * 3-axis accelerometer driver for MXC4005XC Memsic sensor
> + *
> + * Copyright (c) 2014, Intel Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/iio/iio.h>
> +#include <linux/acpi.h>
> +#include <linux/regmap.h>
> +#include <linux/iio/sysfs.h>
> +
> +#define MXC4005_DRV_NAME		"mxc4005"
> +#define MXC4005_REGMAP_NAME		"mxc4005_regmap"
> +
> +#define MXC4005_REG_XOUT_UPPER		0x03
> +#define MXC4005_REG_XOUT_LOWER		0x04
> +#define MXC4005_REG_YOUT_UPPER		0x05
> +#define MXC4005_REG_YOUT_LOWER		0x06
> +#define MXC4005_REG_ZOUT_UPPER		0x07
> +#define MXC4005_REG_ZOUT_LOWER		0x08
> +
> +#define MXC4005_REG_CONTROL		0x0D
> +#define MXC4005_REG_CONTROL_MASK_FSR	GENMASK(6, 5)
> +#define MXC4005_CONTROL_FSR_SHIFT	5
> +
> +#define MXC4005_REG_DEVICE_ID		0x0E
> +
> +#define MXC4005_AXIS_TO_REG(axis)	(MXC4005_REG_XOUT_UPPER + (axis * 2))

maybe parenthesis around (axis)

> +
> +enum mxc4005_axis {
> +	AXIS_X,
> +	AXIS_Y,
> +	AXIS_Z,
> +};
> +
> +enum mxc4005_range {
> +	MXC4005_RANGE_2G,
> +	MXC4005_RANGE_4G,
> +	MXC4005_RANGE_8G,
> +};
> +
> +struct mxc4005_data {
> +	struct i2c_client *client;
> +	struct mutex mutex;
> +	struct regmap *regmap;
> +};
> +
> +/*
> + * MXC4005 can operate in the following ranges:
> + * +/- 2G, 4G, 8G (the default +/-2G)
> + *
> + * (2 + 2) * 9.81 / (2^12 - 1) = 0.009582
> + * (4 + 4) * 9.81 / (2^12 - 1) = 0.019164
> + * (8 + 8) * 9.81 / (2^12 - 1) = 0.038329
> + */
> +static const struct {
> +	u8 range;
> +	u16 scale;

scale should be int

> +} mxc4005_scale_table[] = {
> +	{MXC4005_RANGE_2G, 9582},
> +	{MXC4005_RANGE_4G, 19164},
> +	{MXC4005_RANGE_8G, 38329},
> +};
> +
> +
> +static IIO_CONST_ATTR(in_accel_scale_available, "0.009582 0.019164 0.038329");
> +
> +static struct attribute *mxc4005_attributes[] = {
> +	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group mxc4005_attrs_group = {
> +	.attrs = mxc4005_attributes,
> +};
> +
> +static bool mxc4005_is_readable_reg(struct device *dev, unsigned int reg)
> +{
> +	switch (reg) {
> +	case MXC4005_REG_XOUT_UPPER:
> +	case MXC4005_REG_XOUT_LOWER:
> +	case MXC4005_REG_YOUT_UPPER:
> +	case MXC4005_REG_YOUT_LOWER:
> +	case MXC4005_REG_ZOUT_UPPER:
> +	case MXC4005_REG_ZOUT_LOWER:
> +	case MXC4005_REG_DEVICE_ID:
> +	case MXC4005_REG_CONTROL:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
> +static bool mxc4005_is_writeable_reg(struct device *dev, unsigned int reg)
> +{
> +	switch (reg) {
> +	case MXC4005_REG_CONTROL:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
> +static const struct regmap_config mxc4005_regmap_config = {
> +	.name = MXC4005_DRV_NAME,
> +
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +
> +	.max_register = MXC4005_REG_DEVICE_ID,
> +	.cache_type = REGCACHE_NONE,
> +
> +	.readable_reg = mxc4005_is_readable_reg,
> +	.writeable_reg = mxc4005_is_writeable_reg,
> +};
> +
> +static int mxc4005_read_axis(struct mxc4005_data *data,
> +			     int axis)
> +{
> +	u16 reg;

be16

> +	int ret;
> +
> +	ret = regmap_bulk_read(data->regmap, MXC4005_AXIS_TO_REG(axis),
> +			       (u8 *) &reg, 2);

sizeof(reg) probably

> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "failed to read axis %d\n", axis);
> +		return ret;
> +	}
> +
> +	return reg;
> +}
> +
> +static int mxc4005_read_scale(struct mxc4005_data *data)
> +{
> +	unsigned int reg;
> +	int ret;
> +	int i;
> +
> +	ret = regmap_read(data->regmap, MXC4005_REG_CONTROL, &reg);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "failed to read reg_control");

\n missing

> +		return ret;
> +	}
> +
> +	i = reg >> MXC4005_CONTROL_FSR_SHIFT;

maybe mask the relevant bits...

> +
> +	if (i < 0 || i >= ARRAY_SIZE(mxc4005_scale_table))
> +		return -EINVAL;

.. instead of returning an error

> +
> +	return mxc4005_scale_table[i].scale;
> +}
> +
> +static int mxc4005_set_scale(struct mxc4005_data *data, int val)
> +{
> +	int i;
> +	int ret;
> +	int scale;
> +
> +	for (i = 0; i < ARRAY_SIZE(mxc4005_scale_table); i++) {
> +		if (mxc4005_scale_table[i].scale == val) {
> +			scale = i << MXC4005_CONTROL_FSR_SHIFT;

reg would be a better name for variable scale (and consistent with 
read_scale()), could be moved to local scope

> +			ret = regmap_update_bits(data->regmap,
> +						 MXC4005_REG_CONTROL,
> +						 MXC4005_REG_CONTROL_MASK_FSR,
> +						 scale);
> +			if (ret < 0)
> +				dev_err(&data->client->dev,
> +					"failed to write reg_control %d\n",
> +					ret);

ret is only shown here, but not for read_scale();
maybe "failed to write reg_control, ret = %d\n" would be clearer

> +			return ret;
> +		}
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int mxc4005_read_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int *val, int *val2, long mask)
> +{
> +	struct mxc4005_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		switch (chan->type) {
> +		case IIO_ACCEL:
> +			if (iio_buffer_enabled(indio_dev))
> +				return -EBUSY;
> +
> +			mutex_lock(&data->mutex);
> +			ret = mxc4005_read_axis(data, chan->address);
> +			mutex_unlock(&data->mutex);
> +			if (ret < 0)
> +				return ret;
> +			ret = be16_to_cpu(ret);

I'd move the be16_to_cpu() to read_axis()

> +			*val = sign_extend32(ret >> 4, 11);
> +			return IIO_VAL_INT;
> +		default:
> +			return -EINVAL;
> +		}
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = 0;

maybe move this assignment down where you set val2

> +		mutex_lock(&data->mutex);
> +		ret = mxc4005_read_scale(data);
> +		mutex_unlock(&data->mutex);
> +		if (ret < 0)
> +			return ret;
> +
> +		*val2 = ret;
> +		return IIO_VAL_INT_PLUS_MICRO;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int mxc4005_write_raw(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *chan,
> +			     int val, int val2, long mask)
> +{
> +	struct mxc4005_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SCALE:
> +		if (val != 0)
> +			return -EINVAL;
> +
> +		mutex_lock(&data->mutex);
> +		ret = mxc4005_set_scale(data, val2);
> +		mutex_unlock(&data->mutex);
> +		break;

return ret;

> +	default:
> +		ret = -EINVAL;

return -EINVAL;

> +	}
> +
> +	return ret;
> +}
> +
> +static const struct iio_info mxc4005_info = {
> +	.driver_module	= THIS_MODULE,
> +	.read_raw	= mxc4005_read_raw,
> +	.write_raw	= mxc4005_write_raw,
> +	.attrs		= &mxc4005_attrs_group,
> +};
> +
> +#define MXC4005_CHANNEL(_axis) {				\
> +	.type = IIO_ACCEL,					\
> +	.modified = 1,						\
> +	.channel2 = IIO_MOD_##_axis,				\
> +	.address = AXIS_##_axis,				\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
> +	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
> +}
> +
> +static const struct iio_chan_spec mxc4005_channels[] = {
> +	MXC4005_CHANNEL(X),
> +	MXC4005_CHANNEL(Y),
> +	MXC4005_CHANNEL(Z),
> +};
> +
> +static int mxc4005_chip_init(struct mxc4005_data *data)
> +{
> +	int ret;
> +	unsigned int reg;
> +
> +	ret = regmap_read(data->regmap, MXC4005_REG_DEVICE_ID, &reg);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "failed to read chip id\n");
> +		return ret;
> +	}
> +
> +	dev_dbg(&data->client->dev, "MXC4005 chip id %d\n", reg);

probably better to format as %02x

> +
> +	return 0;
> +}
> +
> +static int mxc4005_probe(struct i2c_client *client,
> +			 const struct i2c_device_id *id)
> +{
> +	struct mxc4005_data *data;
> +	struct iio_dev *indio_dev;
> +	struct regmap *regmap;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	regmap = devm_regmap_init_i2c(client, &mxc4005_regmap_config);
> +	if (IS_ERR(regmap)) {
> +		dev_err(&client->dev, "failed to initialize regmap\n");
> +		return PTR_ERR(regmap);
> +	}
> +
> +	data = iio_priv(indio_dev);
> +	i2c_set_clientdata(client, indio_dev);
> +	data->client = client;
> +	data->regmap = regmap;
> +
> +	ret = mxc4005_chip_init(data);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "failed to init chip\n");
> +		return ret;
> +	}
> +
> +	mutex_init(&data->mutex);
> +
> +	indio_dev->dev.parent = &client->dev;
> +	indio_dev->channels = mxc4005_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(mxc4005_channels);
> +	indio_dev->name = MXC4005_DRV_NAME;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->info = &mxc4005_info;
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0) {
> +		dev_err(&client->dev,
> +			"unable to register iio device %d\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int mxc4005_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> +	iio_device_unregister(indio_dev);
> +
> +	return 0;
> +}
> +
> +static const struct acpi_device_id mxc4005_acpi_match[] = {
> +	{"MXC4005",	0},
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(acpi, mxc4005_acpi_match);
> +
> +static const struct i2c_device_id mxc4005_id[] = {
> +	{"mxc4005",	0},
> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, mxc4005_id);
> +
> +static struct i2c_driver mxc4005_driver = {
> +	.driver = {
> +		.name = MXC4005_DRV_NAME,
> +		.acpi_match_table = ACPI_PTR(mxc4005_acpi_match),
> +	},
> +	.probe		= mxc4005_probe,
> +	.remove		= mxc4005_remove,
> +	.id_table	= mxc4005_id,
> +};
> +
> +module_i2c_driver(mxc4005_driver);
> +
> +MODULE_AUTHOR("Teodora Baluta <teodora.baluta@intel.com>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("MXC4005 3-axis accelerometer driver");
> 

-- 

Peter Meerwald
+43-664-2444418 (mobile)

Re: [PATCH 2/3] iio: mxc4005: add triggered buffer mode for mxc4005

[Peter Meerwald]

On Fri, 31 Jul 2015, Teodora Baluta wrote:

> This patch adds support for buffered readings for the 3-axis
> accelerometer mxc4005.

some comments below
 
> Signed-off-by: Teodora Baluta <teodora.baluta@intel.com>
> ---
>  drivers/iio/accel/Kconfig   |  2 ++
>  drivers/iio/accel/mxc4005.c | 75 ++++++++++++++++++++++++++++++++++++++++++---
>  2 files changed, 73 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index 7f534a3..e8d135e 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -140,6 +140,8 @@ config MMA9553
>  config MXC4005
>  	tristate "Memsic MXC4005XC 3-Axis Accelerometer Driver"
>  	depends on I2C
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
>  	select REGMAP_I2C
>  	help
>  	  Say yes here to build support for the Memsic MXC4005XC 3-axis
> diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c
> index 0f0410c..114c14d 100644
> --- a/drivers/iio/accel/mxc4005.c
> +++ b/drivers/iio/accel/mxc4005.c
> @@ -19,6 +19,9 @@
>  #include <linux/acpi.h>
>  #include <linux/regmap.h>
>  #include <linux/iio/sysfs.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_REGMAP_NAME		"mxc4005_regmap"
> @@ -54,6 +57,7 @@ struct mxc4005_data {
>  	struct i2c_client *client;
>  	struct mutex mutex;
>  	struct regmap *regmap;
> +	s16 buffer[8];

be16 buffer[3]; ?!

>  };
>  
>  /*
> @@ -125,6 +129,20 @@ static const struct regmap_config mxc4005_regmap_config = {
>  	.writeable_reg = mxc4005_is_writeable_reg,
>  };
>  
> +static int mxc4005_read_xyz(struct mxc4005_data *data)
> +{
> +	int ret;
> +
> +	ret = regmap_bulk_read(data->regmap, MXC4005_REG_XOUT_UPPER,
> +			       (u8 *) data->buffer, sizeof(data->buffer));

sizeof(data->buffer) == sizeof(s16) * 8 == 16 bytes, but actually the 
sensor data is just 6 bytes!?

> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "failed to read axes\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
>  static int mxc4005_read_axis(struct mxc4005_data *data,
>  			     int axis)
>  {
> @@ -190,6 +208,7 @@ static int mxc4005_read_raw(struct iio_dev *indio_dev,
>  			    int *val, int *val2, long mask)
>  {
>  	struct mxc4005_data *data = iio_priv(indio_dev);
> +	int axis = chan->scan_index;

why?
BTW w.r.t the initial patch: chan->address could store the register 
address directly, so MXC4005_AXIS_TO_REG() could be dropped

>  	int ret;
>  
>  	switch (mask) {
> @@ -200,12 +219,13 @@ static int mxc4005_read_raw(struct iio_dev *indio_dev,
>  				return -EBUSY;
>  
>  			mutex_lock(&data->mutex);
> -			ret = mxc4005_read_axis(data, chan->address);
> +			ret = mxc4005_read_axis(data, axis);
>  			mutex_unlock(&data->mutex);
>  			if (ret < 0)
>  				return ret;
>  			ret = be16_to_cpu(ret);
> -			*val = sign_extend32(ret >> 4, 11);
> +			*val = sign_extend32(ret >> chan->scan_type.shift,
> +					     chan->scan_type.realbits - 1);
>  			return IIO_VAL_INT;
>  		default:
>  			return -EINVAL;
> @@ -259,17 +279,47 @@ static const struct iio_info mxc4005_info = {
>  	.type = IIO_ACCEL,					\
>  	.modified = 1,						\
>  	.channel2 = IIO_MOD_##_axis,				\
> -	.address = AXIS_##_axis,				\
>  	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
>  	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
> +	.scan_index = AXIS_##_axis,				\
> +	.scan_type = {						\
> +		.sign = 's',					\
> +		.realbits = 12,					\
> +		.storagebits = 16,				\
> +		.shift = 4,					\
> +		.endianness = IIO_BE,				\
> +	},							\
>  }
>  
>  static const struct iio_chan_spec mxc4005_channels[] = {
>  	MXC4005_CHANNEL(X),
>  	MXC4005_CHANNEL(Y),
>  	MXC4005_CHANNEL(Z),
> +	IIO_CHAN_SOFT_TIMESTAMP(3),
>  };
>  
> +static irqreturn_t mxc4005_trigger_handler(int irq, void *private)
> +{
> +	struct iio_poll_func *pf = private;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct mxc4005_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	mutex_lock(&data->mutex);
> +	ret = mxc4005_read_xyz(data);

this always reads all channels, what if only one channel is enabled by the 
user? use available_scan_masks...

> +	mutex_unlock(&data->mutex);
> +	if (ret < 0)
> +		goto err;
> +
> +	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
> +					   iio_get_time_ns());
> +
> +err:
> +	iio_trigger_notify_done(indio_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
>  static int mxc4005_chip_init(struct mxc4005_data *data)
>  {
>  	int ret;
> @@ -324,14 +374,29 @@ static int mxc4005_probe(struct i2c_client *client,
>  	indio_dev->modes = INDIO_DIRECT_MODE;
>  	indio_dev->info = &mxc4005_info;
>  
> +	ret = iio_triggered_buffer_setup(indio_dev,
> +					 &iio_pollfunc_store_time,
> +					 mxc4005_trigger_handler,
> +					 NULL);
> +	if (ret < 0) {
> +		dev_err(&client->dev,
> +			"failed to setup iio triggered buffer\n");
> +		return ret;
> +	}
> +
>  	ret = iio_device_register(indio_dev);
>  	if (ret < 0) {
>  		dev_err(&client->dev,
>  			"unable to register iio device %d\n", ret);
> -		return ret;
> +		goto err_buffer_cleanup;
>  	}
>  
>  	return 0;
> +
> +err_buffer_cleanup:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +
> +	return ret;
>  }
>  
>  static int mxc4005_remove(struct i2c_client *client)
> @@ -340,6 +405,8 @@ static int mxc4005_remove(struct i2c_client *client)
>  
>  	iio_device_unregister(indio_dev);
>  
> +	iio_triggered_buffer_cleanup(indio_dev);
> +
>  	return 0;
>  }
>  
> 

-- 

Peter Meerwald
+43-664-2444418 (mobile)

Re: [PATCH 2/3] iio: mxc4005: add triggered buffer mode for mxc4005

[Teodora Baluta]

On Fri, Jul 31, 2015 at 06:43:57PM +0200, Peter Meerwald wrote:
> On Fri, 31 Jul 2015, Teodora Baluta wrote:
> 
> > This patch adds support for buffered readings for the 3-axis
> > accelerometer mxc4005.
> 
> some comments below

Thanks for the review, Peter. I will send a version 2 patch set as soon
as possible to address the comments.

Teodora

>  
> > Signed-off-by: Teodora Baluta <teodora.baluta@intel.com>
> > ---
> >  drivers/iio/accel/Kconfig   |  2 ++
> >  drivers/iio/accel/mxc4005.c | 75 ++++++++++++++++++++++++++++++++++++++++++---
> >  2 files changed, 73 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> > index 7f534a3..e8d135e 100644
> > --- a/drivers/iio/accel/Kconfig
> > +++ b/drivers/iio/accel/Kconfig
> > @@ -140,6 +140,8 @@ config MMA9553
> >  config MXC4005
> >  	tristate "Memsic MXC4005XC 3-Axis Accelerometer Driver"
> >  	depends on I2C
> > +	select IIO_BUFFER
> > +	select IIO_TRIGGERED_BUFFER
> >  	select REGMAP_I2C
> >  	help
> >  	  Say yes here to build support for the Memsic MXC4005XC 3-axis
> > diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c
> > index 0f0410c..114c14d 100644
> > --- a/drivers/iio/accel/mxc4005.c
> > +++ b/drivers/iio/accel/mxc4005.c
> > @@ -19,6 +19,9 @@
> >  #include <linux/acpi.h>
> >  #include <linux/regmap.h>
> >  #include <linux/iio/sysfs.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_REGMAP_NAME		"mxc4005_regmap"
> > @@ -54,6 +57,7 @@ struct mxc4005_data {
> >  	struct i2c_client *client;
> >  	struct mutex mutex;
> >  	struct regmap *regmap;
> > +	s16 buffer[8];
> 
> be16 buffer[3]; ?!
> 
> >  };
> >  
> >  /*
> > @@ -125,6 +129,20 @@ static const struct regmap_config mxc4005_regmap_config = {
> >  	.writeable_reg = mxc4005_is_writeable_reg,
> >  };
> >  
> > +static int mxc4005_read_xyz(struct mxc4005_data *data)
> > +{
> > +	int ret;
> > +
> > +	ret = regmap_bulk_read(data->regmap, MXC4005_REG_XOUT_UPPER,
> > +			       (u8 *) data->buffer, sizeof(data->buffer));
> 
> sizeof(data->buffer) == sizeof(s16) * 8 == 16 bytes, but actually the 
> sensor data is just 6 bytes!?
> 
> > +	if (ret < 0) {
> > +		dev_err(&data->client->dev, "failed to read axes\n");
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> >  static int mxc4005_read_axis(struct mxc4005_data *data,
> >  			     int axis)
> >  {
> > @@ -190,6 +208,7 @@ static int mxc4005_read_raw(struct iio_dev *indio_dev,
> >  			    int *val, int *val2, long mask)
> >  {
> >  	struct mxc4005_data *data = iio_priv(indio_dev);
> > +	int axis = chan->scan_index;
> 
> why?
> BTW w.r.t the initial patch: chan->address could store the register 
> address directly, so MXC4005_AXIS_TO_REG() could be dropped
> 
> >  	int ret;
> >  
> >  	switch (mask) {
> > @@ -200,12 +219,13 @@ static int mxc4005_read_raw(struct iio_dev *indio_dev,
> >  				return -EBUSY;
> >  
> >  			mutex_lock(&data->mutex);
> > -			ret = mxc4005_read_axis(data, chan->address);
> > +			ret = mxc4005_read_axis(data, axis);
> >  			mutex_unlock(&data->mutex);
> >  			if (ret < 0)
> >  				return ret;
> >  			ret = be16_to_cpu(ret);
> > -			*val = sign_extend32(ret >> 4, 11);
> > +			*val = sign_extend32(ret >> chan->scan_type.shift,
> > +					     chan->scan_type.realbits - 1);
> >  			return IIO_VAL_INT;
> >  		default:
> >  			return -EINVAL;
> > @@ -259,17 +279,47 @@ static const struct iio_info mxc4005_info = {
> >  	.type = IIO_ACCEL,					\
> >  	.modified = 1,						\
> >  	.channel2 = IIO_MOD_##_axis,				\
> > -	.address = AXIS_##_axis,				\
> >  	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
> >  	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
> > +	.scan_index = AXIS_##_axis,				\
> > +	.scan_type = {						\
> > +		.sign = 's',					\
> > +		.realbits = 12,					\
> > +		.storagebits = 16,				\
> > +		.shift = 4,					\
> > +		.endianness = IIO_BE,				\
> > +	},							\
> >  }
> >  
> >  static const struct iio_chan_spec mxc4005_channels[] = {
> >  	MXC4005_CHANNEL(X),
> >  	MXC4005_CHANNEL(Y),
> >  	MXC4005_CHANNEL(Z),
> > +	IIO_CHAN_SOFT_TIMESTAMP(3),
> >  };
> >  
> > +static irqreturn_t mxc4005_trigger_handler(int irq, void *private)
> > +{
> > +	struct iio_poll_func *pf = private;
> > +	struct iio_dev *indio_dev = pf->indio_dev;
> > +	struct mxc4005_data *data = iio_priv(indio_dev);
> > +	int ret;
> > +
> > +	mutex_lock(&data->mutex);
> > +	ret = mxc4005_read_xyz(data);
> 
> this always reads all channels, what if only one channel is enabled by the 
> user? use available_scan_masks...
> 
> > +	mutex_unlock(&data->mutex);
> > +	if (ret < 0)
> > +		goto err;
> > +
> > +	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
> > +					   iio_get_time_ns());
> > +
> > +err:
> > +	iio_trigger_notify_done(indio_dev->trig);
> > +
> > +	return IRQ_HANDLED;
> > +}
> > +
> >  static int mxc4005_chip_init(struct mxc4005_data *data)
> >  {
> >  	int ret;
> > @@ -324,14 +374,29 @@ static int mxc4005_probe(struct i2c_client *client,
> >  	indio_dev->modes = INDIO_DIRECT_MODE;
> >  	indio_dev->info = &mxc4005_info;
> >  
> > +	ret = iio_triggered_buffer_setup(indio_dev,
> > +					 &iio_pollfunc_store_time,
> > +					 mxc4005_trigger_handler,
> > +					 NULL);
> > +	if (ret < 0) {
> > +		dev_err(&client->dev,
> > +			"failed to setup iio triggered buffer\n");
> > +		return ret;
> > +	}
> > +
> >  	ret = iio_device_register(indio_dev);
> >  	if (ret < 0) {
> >  		dev_err(&client->dev,
> >  			"unable to register iio device %d\n", ret);
> > -		return ret;
> > +		goto err_buffer_cleanup;
> >  	}
> >  
> >  	return 0;
> > +
> > +err_buffer_cleanup:
> > +	iio_triggered_buffer_cleanup(indio_dev);
> > +
> > +	return ret;
> >  }
> >  
> >  static int mxc4005_remove(struct i2c_client *client)
> > @@ -340,6 +405,8 @@ static int mxc4005_remove(struct i2c_client *client)
> >  
> >  	iio_device_unregister(indio_dev);
> >  
> > +	iio_triggered_buffer_cleanup(indio_dev);
> > +
> >  	return 0;
> >  }
> >  
> > 
> 
> -- 
> 
> Peter Meerwald
> +43-664-2444418 (mobile)