[PATCH v2] iio: accel: Add support for Freescale MMA7660FC

[PATCH v2] iio: accel: Add support for Freescale MMA7660FC

[Constantin Musca]

Minimal implementation of an IIO driver for the Freescale
MMA7660FC 3-axis accelerometer. Datasheet:
http://www.freescale.com.cn/files/sensors/doc/data_sheet/MMA7660FC.pdf

Includes:
- ACPI support;
- read_raw for x,y,z axes;
- reading and setting the scale (range) parameter.
- power management

Signed-off-by: Constantin Musca <constantin.musca@intel.com>
---
 drivers/iio/accel/Kconfig   |  10 ++
 drivers/iio/accel/Makefile  |   2 +
 drivers/iio/accel/mma7660.c | 275 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 287 insertions(+)
 create mode 100644 drivers/iio/accel/mma7660.c

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index e4a758c..2e6a0e6 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -54,6 +54,16 @@ config HID_SENSOR_ACCEL_3D
 	  To compile this driver as a module, choose M here: the
 	  module will be called hid-sensor-accel-3d.
 
+config MMA7660
+	tristate "Freescale MMA7660FC 3-Axis Accelerometer Driver"
+	depends on I2C
+	help
+	  Say yes here to get support for the Freescale MMA7660FC 3-Axis
+	  accelerometer.
+
+	  Choosing M will build the driver as a module. If so, the module
+	  will be called mma7660.
+
 config IIO_ST_ACCEL_3AXIS
 	tristate "STMicroelectronics accelerometers 3-Axis Driver"
 	depends on (I2C || SPI_MASTER) && SYSFS
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index 71b6794..ba1165f 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -15,6 +15,8 @@ obj-$(CONFIG_MMA7455)		+= mma7455_core.o
 obj-$(CONFIG_MMA7455_I2C)	+= mma7455_i2c.o
 obj-$(CONFIG_MMA7455_SPI)	+= mma7455_spi.o
 
+obj-$(CONFIG_MMA7660)	+= mma7660.o
+
 obj-$(CONFIG_MMA8452)	+= mma8452.o
 
 obj-$(CONFIG_MMA9551_CORE)	+= mma9551_core.o
diff --git a/drivers/iio/accel/mma7660.c b/drivers/iio/accel/mma7660.c
new file mode 100644
index 0000000..9aad91d
--- /dev/null
+++ b/drivers/iio/accel/mma7660.c
@@ -0,0 +1,275 @@
+/**
+ * Freescale MMA7660FC 3-Axis Accelerometer
+ *
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * IIO driver for Freescale MMA7660FC; 7-bit I2C address: 0x4c.
+ */
+
+#include <linux/acpi.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define MMA7660_DRIVER_NAME	"mma7660"
+
+#define MMA7660_REG_XOUT	0x00
+#define MMA7660_REG_YOUT	0x01
+#define MMA7660_REG_ZOUT	0x02
+#define MMA7660_REG_OUT_BIT_ALERT	BIT(6)
+
+#define MMA7660_REG_MODE	0x07
+#define MMA7660_REG_MODE_BIT_MODE	BIT(0)
+#define MMA7660_REG_MODE_BIT_TON	BIT(2)
+
+#define MMA7660_MODE_STANDBY	0
+#define MMA7660_MODE_ACTIVE		1
+
+#define MMA7660_I2C_READ_RETRIES	5
+
+/*
+ * The accelerometer has one measurement range:
+ *
+ * -1.5g - +1.5g (6-bit, signed)
+ *
+ * scale1 = (1.5 + 1.5) * 9.81 / (2^6 - 1)     = 0.467142857
+ */
+
+#define MMA7660_SCALE_AVAIL	"0.467142857"
+
+const int mma7660_nscale = 467142857;
+
+#define MMA7660_CHANNEL(reg, axis) {	\
+	.type = IIO_ACCEL,	\
+	.address = reg,	\
+	.modified = 1,	\
+	.channel2 = IIO_MOD_##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 mma7660_channels[] = {
+	MMA7660_CHANNEL(MMA7660_REG_XOUT, X),
+	MMA7660_CHANNEL(MMA7660_REG_YOUT, Y),
+	MMA7660_CHANNEL(MMA7660_REG_ZOUT, Z),
+};
+
+struct mma7660_data {
+	struct i2c_client *client;
+	struct mutex lock;
+	u8 mode;
+};
+
+static IIO_CONST_ATTR(in_accel_scale_available, MMA7660_SCALE_AVAIL);
+
+static struct attribute *mma7660_attributes[] = {
+	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group mma7660_attribute_group = {
+	.attrs = mma7660_attributes
+};
+
+static int mma7660_set_mode(struct mma7660_data *data, u8 mode)
+{
+	int ret;
+	struct i2c_client *client = data->client;
+
+	if (mode > 1)
+		return -EINVAL;
+
+	if (mode == data->mode)
+		return 0;
+
+	ret = i2c_smbus_read_byte_data(client, MMA7660_REG_MODE);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to change sensor mode\n");
+		return ret;
+	}
+
+	if (mode == MMA7660_MODE_ACTIVE) {
+		ret &= ~MMA7660_REG_MODE_BIT_TON;
+		ret |= MMA7660_REG_MODE_BIT_MODE;
+	} else {
+		ret &= ~MMA7660_REG_MODE_BIT_TON;
+		ret &= ~MMA7660_REG_MODE_BIT_MODE;
+	}
+
+	ret = i2c_smbus_write_byte_data(client, MMA7660_REG_MODE, ret);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to change sensor mode\n");
+		return ret;
+	}
+
+	data->mode = mode;
+	return ret;
+}
+
+static int mma7660_read_accel(struct mma7660_data *data, u8 address)
+{
+	int ret, retries = MMA7660_I2C_READ_RETRIES;
+	struct i2c_client *client = data->client;
+
+	if (address > 2)
+		return -EINVAL;
+
+	do {
+		ret = i2c_smbus_read_byte_data(client, address);
+		if (ret < 0) {
+			dev_err(&client->dev, "register read failed\n");
+			return ret;
+		}
+	} while (--retries > 0 && ret & MMA7660_REG_OUT_BIT_ALERT);
+
+	if (retries == 0) {
+		dev_err(&client->dev, "all register read retries failed");
+		return -ETIMEDOUT;
+	}
+
+	return ret;
+}
+
+static int mma7660_read_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int *val, int *val2, long mask)
+{
+	struct mma7660_data *data = iio_priv(indio_dev);
+	int ret;
+
+	if (chan->type != IIO_ACCEL)
+		return -EINVAL;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&data->lock);
+		ret = mma7660_read_accel(data, chan->address);
+		mutex_unlock(&data->lock);
+		if (ret < 0)
+			return ret;
+		*val = sign_extend32(ret, 5);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = mma7660_nscale;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info mma7660_info = {
+	.driver_module	= THIS_MODULE,
+	.read_raw		= mma7660_read_raw,
+	.attrs			= &mma7660_attribute_group,
+};
+
+static int mma7660_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	int ret;
+	struct iio_dev *indio_dev;
+	struct mma7660_data *data;
+
+	indio_dev = iio_device_alloc(sizeof(*data));
+	if (!indio_dev) {
+		dev_err(&client->dev, "iio allocation failed!\n");
+		return -ENOMEM;
+	}
+
+	data = iio_priv(indio_dev);
+	data->client = client;
+	i2c_set_clientdata(client, indio_dev);
+	mutex_init(&data->lock);
+	data->mode = -1;
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->info = &mma7660_info;
+	indio_dev->name = MMA7660_DRIVER_NAME;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = mma7660_channels;
+	indio_dev->num_channels = ARRAY_SIZE(mma7660_channels);
+
+	ret = mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
+	if (ret < 0)
+		return ret;
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(&client->dev, "device_register failed\n");
+		mma7660_set_mode(data, MMA7660_MODE_STANDBY);
+	}
+
+	return ret;
+}
+
+static int mma7660_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+	iio_device_unregister(indio_dev);
+
+	return mma7660_set_mode(iio_priv(indio_dev), MMA7660_MODE_STANDBY);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mma7660_suspend(struct device *dev)
+{
+	struct mma7660_data *data;
+
+	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+	return mma7660_set_mode(data, MMA7660_MODE_STANDBY);
+}
+
+static int mma7660_resume(struct device *dev)
+{
+	struct mma7660_data *data;
+
+	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+	return mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
+}
+
+static SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend, mma7660_resume);
+
+#define MMA7660_PM_OPS (&mma7660_pm_ops)
+#else
+#define MMA7660_PM_OPS NULL
+#endif
+
+static const struct i2c_device_id mma7660_i2c_id[] = {
+	{"MMA7660", 0},
+	{}
+};
+
+static const struct acpi_device_id mma7660_acpi_id[] = {
+	{"MMA7660", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id);
+
+static struct i2c_driver mma7660_driver = {
+	.driver = {
+		.name = "mma7660",
+		.pm = MMA7660_PM_OPS,
+		.acpi_match_table = ACPI_PTR(mma7660_acpi_id),
+	},
+	.probe		= mma7660_probe,
+	.remove		= mma7660_remove,
+	.id_table	= mma7660_i2c_id,
+};
+
+module_i2c_driver(mma7660_driver);
+
+MODULE_AUTHOR("Constantin Musca <constantin.musca@intel.com>");
+MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1

Re: [PATCH v2] iio: accel: Add support for Freescale MMA7660FC

[Peter Meerwald-Stadler]

On Fri, 29 Apr 2016, Constantin Musca wrote:

> Minimal implementation of an IIO driver for the Freescale
> MMA7660FC 3-axis accelerometer. Datasheet:
> http://www.freescale.com.cn/files/sensors/doc/data_sheet/MMA7660FC.pdf

comments below
 
> Includes:
> - ACPI support;
> - read_raw for x,y,z axes;
> - reading and setting the scale (range) parameter.
> - power management
> 
> Signed-off-by: Constantin Musca <constantin.musca@intel.com>
> ---
>  drivers/iio/accel/Kconfig   |  10 ++
>  drivers/iio/accel/Makefile  |   2 +
>  drivers/iio/accel/mma7660.c | 275 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 287 insertions(+)
>  create mode 100644 drivers/iio/accel/mma7660.c
> 
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index e4a758c..2e6a0e6 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -54,6 +54,16 @@ config HID_SENSOR_ACCEL_3D
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called hid-sensor-accel-3d.
>  
> +config MMA7660
> +	tristate "Freescale MMA7660FC 3-Axis Accelerometer Driver"
> +	depends on I2C
> +	help
> +	  Say yes here to get support for the Freescale MMA7660FC 3-Axis
> +	  accelerometer.
> +
> +	  Choosing M will build the driver as a module. If so, the module
> +	  will be called mma7660.
> +
>  config IIO_ST_ACCEL_3AXIS
>  	tristate "STMicroelectronics accelerometers 3-Axis Driver"
>  	depends on (I2C || SPI_MASTER) && SYSFS
> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
> index 71b6794..ba1165f 100644
> --- a/drivers/iio/accel/Makefile
> +++ b/drivers/iio/accel/Makefile
> @@ -15,6 +15,8 @@ obj-$(CONFIG_MMA7455)		+= mma7455_core.o
>  obj-$(CONFIG_MMA7455_I2C)	+= mma7455_i2c.o
>  obj-$(CONFIG_MMA7455_SPI)	+= mma7455_spi.o
>  
> +obj-$(CONFIG_MMA7660)	+= mma7660.o
> +
>  obj-$(CONFIG_MMA8452)	+= mma8452.o
>  
>  obj-$(CONFIG_MMA9551_CORE)	+= mma9551_core.o
> diff --git a/drivers/iio/accel/mma7660.c b/drivers/iio/accel/mma7660.c
> new file mode 100644
> index 0000000..9aad91d
> --- /dev/null
> +++ b/drivers/iio/accel/mma7660.c
> @@ -0,0 +1,275 @@
> +/**
> + * Freescale MMA7660FC 3-Axis Accelerometer
> + *
> + * Copyright (c) 2016, Intel Corporation.
> + *
> + * This file is subject to the terms and conditions of version 2 of
> + * the GNU General Public License. See the file COPYING in the main
> + * directory of this archive for more details.
> + *
> + * IIO driver for Freescale MMA7660FC; 7-bit I2C address: 0x4c.
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +
> +#define MMA7660_DRIVER_NAME	"mma7660"
> +
> +#define MMA7660_REG_XOUT	0x00
> +#define MMA7660_REG_YOUT	0x01
> +#define MMA7660_REG_ZOUT	0x02
> +#define MMA7660_REG_OUT_BIT_ALERT	BIT(6)
> +
> +#define MMA7660_REG_MODE	0x07
> +#define MMA7660_REG_MODE_BIT_MODE	BIT(0)
> +#define MMA7660_REG_MODE_BIT_TON	BIT(2)
> +
> +#define MMA7660_MODE_STANDBY	0
> +#define MMA7660_MODE_ACTIVE		1

those two could be an enum?

> +
> +#define MMA7660_I2C_READ_RETRIES	5
> +
> +/*
> + * The accelerometer has one measurement range:
> + *
> + * -1.5g - +1.5g (6-bit, signed)
> + *
> + * scale1 = (1.5 + 1.5) * 9.81 / (2^6 - 1)     = 0.467142857

why named scale1?

> + */
> +
> +#define MMA7660_SCALE_AVAIL	"0.467142857"
> +
> +const int mma7660_nscale = 467142857;
> +
> +#define MMA7660_CHANNEL(reg, axis) {	\
> +	.type = IIO_ACCEL,	\
> +	.address = reg,	\
> +	.modified = 1,	\
> +	.channel2 = IIO_MOD_##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 mma7660_channels[] = {
> +	MMA7660_CHANNEL(MMA7660_REG_XOUT, X),
> +	MMA7660_CHANNEL(MMA7660_REG_YOUT, Y),
> +	MMA7660_CHANNEL(MMA7660_REG_ZOUT, Z),
> +};
> +
> +struct mma7660_data {
> +	struct i2c_client *client;
> +	struct mutex lock;
> +	u8 mode;

use enum here

> +};
> +
> +static IIO_CONST_ATTR(in_accel_scale_available, MMA7660_SCALE_AVAIL);
> +
> +static struct attribute *mma7660_attributes[] = {
> +	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group mma7660_attribute_group = {
> +	.attrs = mma7660_attributes
> +};
> +
> +static int mma7660_set_mode(struct mma7660_data *data, u8 mode)
> +{
> +	int ret;
> +	struct i2c_client *client = data->client;
> +
> +	if (mode > 1)
> +		return -EINVAL;

check can probably be dropped

> +
> +	if (mode == data->mode)
> +		return 0;
> +
> +	ret = i2c_smbus_read_byte_data(client, MMA7660_REG_MODE);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "failed to change sensor mode\n");

to read

> +		return ret;
> +	}
> +
> +	if (mode == MMA7660_MODE_ACTIVE) {
> +		ret &= ~MMA7660_REG_MODE_BIT_TON;
> +		ret |= MMA7660_REG_MODE_BIT_MODE;
> +	} else {
> +		ret &= ~MMA7660_REG_MODE_BIT_TON;
> +		ret &= ~MMA7660_REG_MODE_BIT_MODE;
> +	}
> +
> +	ret = i2c_smbus_write_byte_data(client, MMA7660_REG_MODE, ret);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "failed to change sensor mode\n");
> +		return ret;
> +	}
> +
> +	data->mode = mode;
> +	return ret;
> +}
> +
> +static int mma7660_read_accel(struct mma7660_data *data, u8 address)
> +{
> +	int ret, retries = MMA7660_I2C_READ_RETRIES;
> +	struct i2c_client *client = data->client;
> +
> +	if (address > 2)
> +		return -EINVAL;

check needed?

> +
> +	do {
> +		ret = i2c_smbus_read_byte_data(client, address);
> +		if (ret < 0) {
> +			dev_err(&client->dev, "register read failed\n");
> +			return ret;
> +		}
> +	} while (--retries > 0 && ret & MMA7660_REG_OUT_BIT_ALERT);

if READ_RETRIES were 1, this would always fail, no matter what 
OUT_BIT_ALERT is 

> +
> +	if (retries == 0) {
> +		dev_err(&client->dev, "all register read retries failed");
> +		return -ETIMEDOUT;
> +	}
> +
> +	return ret;
> +}
> +
> +static int mma7660_read_raw(struct iio_dev *indio_dev,
> +				struct iio_chan_spec const *chan,
> +				int *val, int *val2, long mask)
> +{
> +	struct mma7660_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	if (chan->type != IIO_ACCEL)
> +		return -EINVAL;

check needed?

> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		mutex_lock(&data->lock);
> +		ret = mma7660_read_accel(data, chan->address);
> +		mutex_unlock(&data->lock);
> +		if (ret < 0)
> +			return ret;
> +		*val = sign_extend32(ret, 5);
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = 0;
> +		*val2 = mma7660_nscale;

nscale is NANO, not MICRO?

> +		return IIO_VAL_INT_PLUS_MICRO;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static const struct iio_info mma7660_info = {
> +	.driver_module	= THIS_MODULE,
> +	.read_raw		= mma7660_read_raw,
> +	.attrs			= &mma7660_attribute_group,
> +};
> +
> +static int mma7660_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	int ret;
> +	struct iio_dev *indio_dev;
> +	struct mma7660_data *data;
> +
> +	indio_dev = iio_device_alloc(sizeof(*data));

devm_

> +	if (!indio_dev) {
> +		dev_err(&client->dev, "iio allocation failed!\n");
> +		return -ENOMEM;
> +	}
> +
> +	data = iio_priv(indio_dev);
> +	data->client = client;
> +	i2c_set_clientdata(client, indio_dev);
> +	mutex_init(&data->lock);
> +	data->mode = -1;

MODE_STANDBY probably

> +
> +	indio_dev->dev.parent = &client->dev;
> +	indio_dev->info = &mma7660_info;
> +	indio_dev->name = MMA7660_DRIVER_NAME;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = mma7660_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(mma7660_channels);
> +
> +	ret = mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "device_register failed\n");
> +		mma7660_set_mode(data, MMA7660_MODE_STANDBY);
> +	}
> +
> +	return ret;
> +}
> +
> +static int mma7660_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> +	iio_device_unregister(indio_dev);
> +
> +	return mma7660_set_mode(iio_priv(indio_dev), MMA7660_MODE_STANDBY);
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int mma7660_suspend(struct device *dev)
> +{
> +	struct mma7660_data *data;
> +
> +	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
> +
> +	return mma7660_set_mode(data, MMA7660_MODE_STANDBY);
> +}
> +
> +static int mma7660_resume(struct device *dev)
> +{
> +	struct mma7660_data *data;
> +
> +	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
> +
> +	return mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
> +}
> +
> +static SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend, mma7660_resume);
> +
> +#define MMA7660_PM_OPS (&mma7660_pm_ops)
> +#else
> +#define MMA7660_PM_OPS NULL
> +#endif
> +
> +static const struct i2c_device_id mma7660_i2c_id[] = {
> +	{"MMA7660", 0},

really uppercase?

> +	{}
> +};
> +
> +static const struct acpi_device_id mma7660_acpi_id[] = {
> +	{"MMA7660", 0},
> +	{}
> +};
> +
> +MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id);
> +
> +static struct i2c_driver mma7660_driver = {
> +	.driver = {
> +		.name = "mma7660",
> +		.pm = MMA7660_PM_OPS,
> +		.acpi_match_table = ACPI_PTR(mma7660_acpi_id),
> +	},
> +	.probe		= mma7660_probe,
> +	.remove		= mma7660_remove,
> +	.id_table	= mma7660_i2c_id,
> +};
> +
> +module_i2c_driver(mma7660_driver);
> +
> +MODULE_AUTHOR("Constantin Musca <constantin.musca@intel.com>");
> +MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver");
> +MODULE_LICENSE("GPL v2");
> 

-- 

Peter Meerwald-Stadler
+43-664-2444418 (mobile)

Re: [PATCH v2] iio: accel: Add support for Freescale MMA7660FC

[Constantin Musca]

Thanks. Please see patch v3.

Constantin

On 29.04.2016 11:05, Peter Meerwald-Stadler wrote:
> On Fri, 29 Apr 2016, Constantin Musca wrote:
>
>> Minimal implementation of an IIO driver for the Freescale
>> MMA7660FC 3-axis accelerometer. Datasheet:
>> http://www.freescale.com.cn/files/sensors/doc/data_sheet/MMA7660FC.pdf
> comments below
>   
>> Includes:
>> - ACPI support;
>> - read_raw for x,y,z axes;
>> - reading and setting the scale (range) parameter.
>> - power management
>>
>> Signed-off-by: Constantin Musca <constantin.musca@intel.com>
>> ---
>>   drivers/iio/accel/Kconfig   |  10 ++
>>   drivers/iio/accel/Makefile  |   2 +
>>   drivers/iio/accel/mma7660.c | 275 ++++++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 287 insertions(+)
>>   create mode 100644 drivers/iio/accel/mma7660.c
>>
>> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
>> index e4a758c..2e6a0e6 100644
>> --- a/drivers/iio/accel/Kconfig
>> +++ b/drivers/iio/accel/Kconfig
>> @@ -54,6 +54,16 @@ config HID_SENSOR_ACCEL_3D
>>   	  To compile this driver as a module, choose M here: the
>>   	  module will be called hid-sensor-accel-3d.
>>   
>> +config MMA7660
>> +	tristate "Freescale MMA7660FC 3-Axis Accelerometer Driver"
>> +	depends on I2C
>> +	help
>> +	  Say yes here to get support for the Freescale MMA7660FC 3-Axis
>> +	  accelerometer.
>> +
>> +	  Choosing M will build the driver as a module. If so, the module
>> +	  will be called mma7660.
>> +
>>   config IIO_ST_ACCEL_3AXIS
>>   	tristate "STMicroelectronics accelerometers 3-Axis Driver"
>>   	depends on (I2C || SPI_MASTER) && SYSFS
>> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
>> index 71b6794..ba1165f 100644
>> --- a/drivers/iio/accel/Makefile
>> +++ b/drivers/iio/accel/Makefile
>> @@ -15,6 +15,8 @@ obj-$(CONFIG_MMA7455)		+= mma7455_core.o
>>   obj-$(CONFIG_MMA7455_I2C)	+= mma7455_i2c.o
>>   obj-$(CONFIG_MMA7455_SPI)	+= mma7455_spi.o
>>   
>> +obj-$(CONFIG_MMA7660)	+= mma7660.o
>> +
>>   obj-$(CONFIG_MMA8452)	+= mma8452.o
>>   
>>   obj-$(CONFIG_MMA9551_CORE)	+= mma9551_core.o
>> diff --git a/drivers/iio/accel/mma7660.c b/drivers/iio/accel/mma7660.c
>> new file mode 100644
>> index 0000000..9aad91d
>> --- /dev/null
>> +++ b/drivers/iio/accel/mma7660.c
>> @@ -0,0 +1,275 @@
>> +/**
>> + * Freescale MMA7660FC 3-Axis Accelerometer
>> + *
>> + * Copyright (c) 2016, Intel Corporation.
>> + *
>> + * This file is subject to the terms and conditions of version 2 of
>> + * the GNU General Public License. See the file COPYING in the main
>> + * directory of this archive for more details.
>> + *
>> + * IIO driver for Freescale MMA7660FC; 7-bit I2C address: 0x4c.
>> + */
>> +
>> +#include <linux/acpi.h>
>> +#include <linux/i2c.h>
>> +#include <linux/module.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/sysfs.h>
>> +
>> +#define MMA7660_DRIVER_NAME	"mma7660"
>> +
>> +#define MMA7660_REG_XOUT	0x00
>> +#define MMA7660_REG_YOUT	0x01
>> +#define MMA7660_REG_ZOUT	0x02
>> +#define MMA7660_REG_OUT_BIT_ALERT	BIT(6)
>> +
>> +#define MMA7660_REG_MODE	0x07
>> +#define MMA7660_REG_MODE_BIT_MODE	BIT(0)
>> +#define MMA7660_REG_MODE_BIT_TON	BIT(2)
>> +
>> +#define MMA7660_MODE_STANDBY	0
>> +#define MMA7660_MODE_ACTIVE		1
> those two could be an enum?
>
>> +
>> +#define MMA7660_I2C_READ_RETRIES	5
>> +
>> +/*
>> + * The accelerometer has one measurement range:
>> + *
>> + * -1.5g - +1.5g (6-bit, signed)
>> + *
>> + * scale1 = (1.5 + 1.5) * 9.81 / (2^6 - 1)     = 0.467142857
> why named scale1?
>
>> + */
>> +
>> +#define MMA7660_SCALE_AVAIL	"0.467142857"
>> +
>> +const int mma7660_nscale = 467142857;
>> +
>> +#define MMA7660_CHANNEL(reg, axis) {	\
>> +	.type = IIO_ACCEL,	\
>> +	.address = reg,	\
>> +	.modified = 1,	\
>> +	.channel2 = IIO_MOD_##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 mma7660_channels[] = {
>> +	MMA7660_CHANNEL(MMA7660_REG_XOUT, X),
>> +	MMA7660_CHANNEL(MMA7660_REG_YOUT, Y),
>> +	MMA7660_CHANNEL(MMA7660_REG_ZOUT, Z),
>> +};
>> +
>> +struct mma7660_data {
>> +	struct i2c_client *client;
>> +	struct mutex lock;
>> +	u8 mode;
> use enum here
>
>> +};
>> +
>> +static IIO_CONST_ATTR(in_accel_scale_available, MMA7660_SCALE_AVAIL);
>> +
>> +static struct attribute *mma7660_attributes[] = {
>> +	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
>> +	NULL,
>> +};
>> +
>> +static const struct attribute_group mma7660_attribute_group = {
>> +	.attrs = mma7660_attributes
>> +};
>> +
>> +static int mma7660_set_mode(struct mma7660_data *data, u8 mode)
>> +{
>> +	int ret;
>> +	struct i2c_client *client = data->client;
>> +
>> +	if (mode > 1)
>> +		return -EINVAL;
> check can probably be dropped
>
>> +
>> +	if (mode == data->mode)
>> +		return 0;
>> +
>> +	ret = i2c_smbus_read_byte_data(client, MMA7660_REG_MODE);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "failed to change sensor mode\n");
> to read
>
>> +		return ret;
>> +	}
>> +
>> +	if (mode == MMA7660_MODE_ACTIVE) {
>> +		ret &= ~MMA7660_REG_MODE_BIT_TON;
>> +		ret |= MMA7660_REG_MODE_BIT_MODE;
>> +	} else {
>> +		ret &= ~MMA7660_REG_MODE_BIT_TON;
>> +		ret &= ~MMA7660_REG_MODE_BIT_MODE;
>> +	}
>> +
>> +	ret = i2c_smbus_write_byte_data(client, MMA7660_REG_MODE, ret);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "failed to change sensor mode\n");
>> +		return ret;
>> +	}
>> +
>> +	data->mode = mode;
>> +	return ret;
>> +}
>> +
>> +static int mma7660_read_accel(struct mma7660_data *data, u8 address)
>> +{
>> +	int ret, retries = MMA7660_I2C_READ_RETRIES;
>> +	struct i2c_client *client = data->client;
>> +
>> +	if (address > 2)
>> +		return -EINVAL;
> check needed?
>
>> +
>> +	do {
>> +		ret = i2c_smbus_read_byte_data(client, address);
>> +		if (ret < 0) {
>> +			dev_err(&client->dev, "register read failed\n");
>> +			return ret;
>> +		}
>> +	} while (--retries > 0 && ret & MMA7660_REG_OUT_BIT_ALERT);
> if READ_RETRIES were 1, this would always fail, no matter what
> OUT_BIT_ALERT is
>
>> +
>> +	if (retries == 0) {
>> +		dev_err(&client->dev, "all register read retries failed");
>> +		return -ETIMEDOUT;
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int mma7660_read_raw(struct iio_dev *indio_dev,
>> +				struct iio_chan_spec const *chan,
>> +				int *val, int *val2, long mask)
>> +{
>> +	struct mma7660_data *data = iio_priv(indio_dev);
>> +	int ret;
>> +
>> +	if (chan->type != IIO_ACCEL)
>> +		return -EINVAL;
> check needed?
>
>> +
>> +	switch (mask) {
>> +	case IIO_CHAN_INFO_RAW:
>> +		mutex_lock(&data->lock);
>> +		ret = mma7660_read_accel(data, chan->address);
>> +		mutex_unlock(&data->lock);
>> +		if (ret < 0)
>> +			return ret;
>> +		*val = sign_extend32(ret, 5);
>> +		return IIO_VAL_INT;
>> +	case IIO_CHAN_INFO_SCALE:
>> +		*val = 0;
>> +		*val2 = mma7660_nscale;
> nscale is NANO, not MICRO?
>
>> +		return IIO_VAL_INT_PLUS_MICRO;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +
>> +	return -EINVAL;
>> +}
>> +
>> +static const struct iio_info mma7660_info = {
>> +	.driver_module	= THIS_MODULE,
>> +	.read_raw		= mma7660_read_raw,
>> +	.attrs			= &mma7660_attribute_group,
>> +};
>> +
>> +static int mma7660_probe(struct i2c_client *client,
>> +			const struct i2c_device_id *id)
>> +{
>> +	int ret;
>> +	struct iio_dev *indio_dev;
>> +	struct mma7660_data *data;
>> +
>> +	indio_dev = iio_device_alloc(sizeof(*data));
> devm_
>
>> +	if (!indio_dev) {
>> +		dev_err(&client->dev, "iio allocation failed!\n");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	data = iio_priv(indio_dev);
>> +	data->client = client;
>> +	i2c_set_clientdata(client, indio_dev);
>> +	mutex_init(&data->lock);
>> +	data->mode = -1;
> MODE_STANDBY probably
>
>> +
>> +	indio_dev->dev.parent = &client->dev;
>> +	indio_dev->info = &mma7660_info;
>> +	indio_dev->name = MMA7660_DRIVER_NAME;
>> +	indio_dev->modes = INDIO_DIRECT_MODE;
>> +	indio_dev->channels = mma7660_channels;
>> +	indio_dev->num_channels = ARRAY_SIZE(mma7660_channels);
>> +
>> +	ret = mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	ret = iio_device_register(indio_dev);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "device_register failed\n");
>> +		mma7660_set_mode(data, MMA7660_MODE_STANDBY);
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int mma7660_remove(struct i2c_client *client)
>> +{
>> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
>> +
>> +	iio_device_unregister(indio_dev);
>> +
>> +	return mma7660_set_mode(iio_priv(indio_dev), MMA7660_MODE_STANDBY);
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int mma7660_suspend(struct device *dev)
>> +{
>> +	struct mma7660_data *data;
>> +
>> +	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
>> +
>> +	return mma7660_set_mode(data, MMA7660_MODE_STANDBY);
>> +}
>> +
>> +static int mma7660_resume(struct device *dev)
>> +{
>> +	struct mma7660_data *data;
>> +
>> +	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
>> +
>> +	return mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
>> +}
>> +
>> +static SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend, mma7660_resume);
>> +
>> +#define MMA7660_PM_OPS (&mma7660_pm_ops)
>> +#else
>> +#define MMA7660_PM_OPS NULL
>> +#endif
>> +
>> +static const struct i2c_device_id mma7660_i2c_id[] = {
>> +	{"MMA7660", 0},
> really uppercase?
>
>> +	{}
>> +};
>> +
>> +static const struct acpi_device_id mma7660_acpi_id[] = {
>> +	{"MMA7660", 0},
>> +	{}
>> +};
>> +
>> +MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id);
>> +
>> +static struct i2c_driver mma7660_driver = {
>> +	.driver = {
>> +		.name = "mma7660",
>> +		.pm = MMA7660_PM_OPS,
>> +		.acpi_match_table = ACPI_PTR(mma7660_acpi_id),
>> +	},
>> +	.probe		= mma7660_probe,
>> +	.remove		= mma7660_remove,
>> +	.id_table	= mma7660_i2c_id,
>> +};
>> +
>> +module_i2c_driver(mma7660_driver);
>> +
>> +MODULE_AUTHOR("Constantin Musca <constantin.musca@intel.com>");
>> +MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver");
>> +MODULE_LICENSE("GPL v2");
>>