Re: [PATCH v2] iio: accel: Add driver for dmard10 3-axis Accelerometer

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 25-09-16 10:38, Jonathan Cameron wrote:
> On 19/09/16 19:48, Hans de Goede wrote:
>> Add a driver for the Domintech ARD10 3-axis Accelerometer, based on the
>> android driver found here: https://github.com/domintech/dmard10
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> Hi Hans,
>
> I'm wondering if I missed it in your other accelerometer drivers
> (if so please send fixes!)
>
> Units of acceleration in IIO are m/s^2. We try to stick
> to SI units where possible (there are some quirks due to
> early attempts to maintain compatibility with Hwmon units).

Ah, good catch. I'll send a v3 fixing this, I'll also
fix this in the v3 of the da311 driver. I did not make this mistake
in the mCube mc3230 driver.

Regards,

Hans


>
> Otherwise, very nice.
>
> Jonathan
>> ---
>> Changes in v2:
>> -prefix all defines with DMARD10_ and uppercase them all
>> -Cleanup typography of some comments
>> -Use defines for offsets in databuffer
>> -Use i2c_smbus_write_byte_data() where applicable
>> -Reduce unnecessarily large buffer size in dmard10_shutdown()
>> -Use __le16 buffer in dmard10_read_raw()
>> ---
>>  .../devicetree/bindings/i2c/trivial-devices.txt    |   1 +
>>  drivers/iio/accel/Kconfig                          |  10 +
>>  drivers/iio/accel/Makefile                         |   1 +
>>  drivers/iio/accel/dmard10.c                        | 266 +++++++++++++++++++++
>>  4 files changed, 278 insertions(+)
>>  create mode 100644 drivers/iio/accel/dmard10.c
>>
>> diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>> index fbbad64..21ca02e 100644
>> --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>> +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>> @@ -39,6 +39,7 @@ dallas,ds75		Digital Thermometer and Thermostat
>>  dlg,da9053		DA9053: flexible system level PMIC with multicore support
>>  dlg,da9063		DA9063: system PMIC for quad-core application processors
>>  domintech,dmard09	DMARD09: 3-axis Accelerometer
>> +domintech,dmard10	DMARD10: 3-axis Accelerometer
>>  epson,rx8010		I2C-BUS INTERFACE REAL TIME CLOCK MODULE
>>  epson,rx8025		High-Stability. I2C-Bus INTERFACE REAL TIME CLOCK MODULE
>>  epson,rx8581		I2C-BUS INTERFACE REAL TIME CLOCK MODULE
>> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
>> index 6bf1b64..6236fd5 100644
>> --- a/drivers/iio/accel/Kconfig
>> +++ b/drivers/iio/accel/Kconfig
>> @@ -73,6 +73,16 @@ config DMARD09
>>  	  Choosing M will build the driver as a module. If so, the module
>>  	  will be called dmard09.
>>
>> +config DMARD10
>> +	tristate "Domintech DMARD10 3-axis Accelerometer Driver"
>> +	depends on I2C
>> +	help
>> +	  Say yes here to get support for the Domintech DMARD10 3-axis
>> +	  accelerometer.
>> +
>> +	  Choosing M will build the driver as a module. If so, the module
>> +	  will be called dmard10.
>> +
>>  config HID_SENSOR_ACCEL_3D
>>  	depends on HID_SENSOR_HUB
>>  	select IIO_BUFFER
>> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
>> index 07a0c72..9f51559 100644
>> --- a/drivers/iio/accel/Makefile
>> +++ b/drivers/iio/accel/Makefile
>> @@ -10,6 +10,7 @@ obj-$(CONFIG_BMC150_ACCEL_I2C) += bmc150-accel-i2c.o
>>  obj-$(CONFIG_BMC150_ACCEL_SPI) += bmc150-accel-spi.o
>>  obj-$(CONFIG_DMARD06)	+= dmard06.o
>>  obj-$(CONFIG_DMARD09)	+= dmard09.o
>> +obj-$(CONFIG_DMARD10)	+= dmard10.o
>>  obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o
>>  obj-$(CONFIG_KXCJK1013) += kxcjk-1013.o
>>  obj-$(CONFIG_KXSD9)	+= kxsd9.o
>> diff --git a/drivers/iio/accel/dmard10.c b/drivers/iio/accel/dmard10.c
>> new file mode 100644
>> index 0000000..f8bacd2
>> --- /dev/null
>> +++ b/drivers/iio/accel/dmard10.c
>> @@ -0,0 +1,266 @@
>> +/**
>> + * IIO driver for the 3-axis accelerometer Domintech ARD10.
>> + *
>> + * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
>> + * Copyright (c) 2012 Domintech Technology Co., Ltd
>> + *
>> + * 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.
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/i2c.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/sysfs.h>
>> +#include <linux/byteorder/generic.h>
>> +
>> +#define DMARD10_REG_ACTR			0x00
>> +#define DMARD10_REG_AFEM			0x0c
>> +#define DMARD10_REG_STADR			0x12
>> +#define DMARD10_REG_STAINT			0x1c
>> +#define DMARD10_REG_MISC2			0x1f
>> +#define DMARD10_REG_PD				0x21
>> +
>> +#define DMARD10_MODE_OFF			0x00
>> +#define DMARD10_MODE_STANDBY			0x02
>> +#define DMARD10_MODE_ACTIVE			0x06
>> +#define DMARD10_MODE_READ_OTP			0x12
>> +#define DMARD10_MODE_RESET_DATA_PATH		0x82
>> +
>> +/* AFEN set 1, ATM[2:0]=b'000 (normal), EN_Z/Y/X/T=1 */
>> +#define DMARD10_VALUE_AFEM_AFEN_NORMAL		0x8f
>> +/* ODR[3:0]=b'0111 (100Hz), CCK[3:0]=b'0100 (204.8kHZ) */
>> +#define DMARD10_VALUE_CKSEL_ODR_100_204		0x74
>> +/* INTC[6:5]=b'00 */
>> +#define DMARD10_VALUE_INTC			0x00
>> +/* TAP1/TAP2 Average 2 */
>> +#define DMARD10_VALUE_TAPNS_AVE_2		0x11
>> +
>> +#define DMARD10_VALUE_STADR			0x55
>> +#define DMARD10_VALUE_STAINT			0xaa
>> +#define DMARD10_VALUE_MISC2_OSCA_EN		0x08
>> +#define DMARD10_VALUE_PD_RST			0x52
>> +
>> +/* Offsets into the buffer read in dmard10_read_raw() */
>> +#define DMARD10_X_OFFSET			1
>> +#define DMARD10_Y_OFFSET			2
>> +#define DMARD10_Z_OFFSET			3
>> +
>> +/*
>> + * a value of + or -128 corresponds to + or - 1G
>> + * scale = 1 / 128 = 0.007812500
> Units in IIO for acceleration are m/s^2
> Also for reference if it had been the above we have the
> fractional return types which make this sort of value
> easier to handle (also useful via in kernel interfaces
> as it may never be necessary to do the division)..
>> + */
>> +
>> +static const int dmard10_nscale = 7812500;
>> +
>> +#define DMARD10_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 dmard10_channels[] = {
>> +	DMARD10_CHANNEL(DMARD10_X_OFFSET, X),
>> +	DMARD10_CHANNEL(DMARD10_Y_OFFSET, Y),
>> +	DMARD10_CHANNEL(DMARD10_Z_OFFSET, Z),
>> +};
>> +
>> +struct dmard10_data {
>> +	struct i2c_client *client;
>> +};
>> +
>> +/* Init sequence taken from the android driver */
>> +static int dmard10_reset(struct i2c_client *client)
>> +{
>> +	unsigned char buffer[7];
>> +	int ret;
>> +
>> +	/* 1. Powerdown reset */
>> +	ret = i2c_smbus_write_byte_data(client, DMARD10_REG_PD,
>> +						DMARD10_VALUE_PD_RST);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	/*
>> +	 * 2. ACTR => Standby mode => Download OTP to parameter reg =>
>> +	 *    Standby mode => Reset data path => Standby mode
>> +	 */
>> +	buffer[0] = DMARD10_REG_ACTR;
>> +	buffer[1] = DMARD10_MODE_STANDBY;
>> +	buffer[2] = DMARD10_MODE_READ_OTP;
>> +	buffer[3] = DMARD10_MODE_STANDBY;
>> +	buffer[4] = DMARD10_MODE_RESET_DATA_PATH;
>> +	buffer[5] = DMARD10_MODE_STANDBY;
>> +	ret = i2c_master_send(client, buffer, 6);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	/* 3. OSCA_EN = 1, TSTO = b'000 (INT1 = normal, TEST0 = normal) */
>> +	ret = i2c_smbus_write_byte_data(client, DMARD10_REG_MISC2,
>> +						DMARD10_VALUE_MISC2_OSCA_EN);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	/* 4. AFEN = 1 (AFE will powerdown after ADC) */
>> +	buffer[0] = DMARD10_REG_AFEM;
>> +	buffer[1] = DMARD10_VALUE_AFEM_AFEN_NORMAL;
>> +	buffer[2] = DMARD10_VALUE_CKSEL_ODR_100_204;
>> +	buffer[3] = DMARD10_VALUE_INTC;
>> +	buffer[4] = DMARD10_VALUE_TAPNS_AVE_2;
>> +	buffer[5] = 0x00; /* DLYC, no delay timing */
>> +	buffer[6] = 0x07; /* INTD=1 push-pull, INTA=1 active high, AUTOT=1 */
>> +	ret = i2c_master_send(client, buffer, 7);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	/* 5. Activation mode */
>> +	ret = i2c_smbus_write_byte_data(client, DMARD10_REG_ACTR,
>> +						DMARD10_MODE_ACTIVE);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	return 0;
>> +}
>> +
>> +/* Shutdown sequence taken from the android driver */
>> +static int dmard10_shutdown(struct i2c_client *client)
>> +{
>> +	unsigned char buffer[3];
>> +
>> +	buffer[0] = DMARD10_REG_ACTR;
>> +	buffer[1] = DMARD10_MODE_STANDBY;
>> +	buffer[2] = DMARD10_MODE_OFF;
>> +
>> +	return i2c_master_send(client, buffer, 3);
>> +}
>> +
>> +static int dmard10_read_raw(struct iio_dev *indio_dev,
>> +				struct iio_chan_spec const *chan,
>> +				int *val, int *val2, long mask)
>> +{
>> +	struct dmard10_data *data = iio_priv(indio_dev);
>> +	__le16 buf[4];
>> +	int ret;
>> +
>> +	switch (mask) {
>> +	case IIO_CHAN_INFO_RAW:
>> +		/*
>> +		 * Read 8 bytes starting at the REG_STADR register, trying to
>> +		 * read the individual X, Y, Z registers will always read 0.
>> +		 */
>> +		ret = i2c_smbus_read_i2c_block_data(data->client,
>> +						    DMARD10_REG_STADR,
>> +						    sizeof(buf), (u8 *)buf);
>> +		if (ret < 0)
>> +			return ret;
>> +		ret = le16_to_cpu(buf[chan->address]);
>> +		*val = sign_extend32(ret, 12);
>> +		return IIO_VAL_INT;
>> +	case IIO_CHAN_INFO_SCALE:
>> +		*val = 0;
>> +		*val2 = dmard10_nscale;
>> +		return IIO_VAL_INT_PLUS_NANO;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +}
>> +
>> +static const struct iio_info dmard10_info = {
>> +	.driver_module	= THIS_MODULE,
>> +	.read_raw	= dmard10_read_raw,
>> +};
>> +
>> +static int dmard10_probe(struct i2c_client *client,
>> +			const struct i2c_device_id *id)
>> +{
>> +	int ret;
>> +	struct iio_dev *indio_dev;
>> +	struct dmard10_data *data;
>> +
>> +	/* These 2 registers have special POR reset values used for id */
>> +	ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STADR);
>> +	if (ret != DMARD10_VALUE_STADR)
>> +		return (ret < 0) ? ret : -ENODEV;
>> +
>> +	ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STAINT);
>> +	if (ret != DMARD10_VALUE_STAINT)
>> +		return (ret < 0) ? ret : -ENODEV;
>> +
>> +	indio_dev = devm_iio_device_alloc(&client->dev, 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);
>> +
>> +	indio_dev->dev.parent = &client->dev;
>> +	indio_dev->info = &dmard10_info;
>> +	indio_dev->name = "dmard10";
>> +	indio_dev->modes = INDIO_DIRECT_MODE;
>> +	indio_dev->channels = dmard10_channels;
>> +	indio_dev->num_channels = ARRAY_SIZE(dmard10_channels);
>> +
>> +	ret = dmard10_reset(client);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	ret = iio_device_register(indio_dev);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "device_register failed\n");
>> +		dmard10_shutdown(client);
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int dmard10_remove(struct i2c_client *client)
>> +{
>> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
>> +
>> +	iio_device_unregister(indio_dev);
>> +
>> +	return dmard10_shutdown(client);
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int dmard10_suspend(struct device *dev)
>> +{
>> +	return dmard10_shutdown(to_i2c_client(dev));
>> +}
>> +
>> +static int dmard10_resume(struct device *dev)
>> +{
>> +	return dmard10_reset(to_i2c_client(dev));
>> +}
>> +#endif
>> +
>> +static SIMPLE_DEV_PM_OPS(dmard10_pm_ops, dmard10_suspend, dmard10_resume);
>> +
>> +static const struct i2c_device_id dmard10_i2c_id[] = {
>> +	{"dmard10", 0},
>> +	{}
>> +};
>> +MODULE_DEVICE_TABLE(i2c, dmard10_i2c_id);
>> +
>> +static struct i2c_driver dmard10_driver = {
>> +	.driver = {
>> +		.name = "dmard10",
>> +		.pm = &dmard10_pm_ops,
>> +	},
>> +	.probe		= dmard10_probe,
>> +	.remove		= dmard10_remove,
>> +	.id_table	= dmard10_i2c_id,
>> +};
>> +
>> +module_i2c_driver(dmard10_driver);
>> +
>> +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
>> +MODULE_DESCRIPTION("Domintech ARD10 3-Axis Accelerometer driver");
>> +MODULE_LICENSE("GPL v2");
>>
>