Re: [PATCH v2] iio: accel: Add driver for the MiraMEMS DA311 3-axis 12-bit digital accelerometer

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

Hi,

On 09/22/2016 08:10 PM, Jonathan Cameron wrote:
> On 22/09/16 14:42, Hans de Goede wrote:
>> This driver is based on the DA311 Android driver which can be found here:
>> https://git.matricom.net/Firmware/kernel_amlogic_meson-common/tree/1e70113a5befd07debb68f537156def84c5be57a/drivers/amlogic/input/sensor
>> the mir3da_* files are the DA311 driver.
>>
>> Unfortunately there is no datasheet.
>>
> I was crossing my fingers that it was similar to the 312 which does have
> a datasheet on their website. No such luck.

Yeah, I also looked at the da312 datasheet, but no luck indeed.

> Looks good. Couple of really minor comment inline. I'd like this to sit
> on the mailing list a bit longer. Unfortunately it's just missed the
> upcoming merge window so we have lots and lots of time :)
>
> Jonathan
>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>> Changes in v2:
>> -Add proper prefix to patch Subject
>> -Use i2c_smbus_read_word_data() instead of i2c_smbus_read_i2c_block_data()
>> ---
>>  .../devicetree/bindings/i2c/trivial-devices.txt    |   1 +
>>  drivers/iio/accel/Kconfig                          |  10 +
>>  drivers/iio/accel/Makefile                         |   1 +
>>  drivers/iio/accel/da311.c                          | 305 +++++++++++++++++++++
>>  4 files changed, 317 insertions(+)
>>  create mode 100644 drivers/iio/accel/da311.c
>>
>> diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>> index 21ca02e..8ad9064 100644
>> --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>> +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>> @@ -122,6 +122,7 @@ microchip,mcp4662-502	Microchip 8-bit Dual I2C Digital Potentiometer with NV Mem
>>  microchip,mcp4662-103	Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (10k)
>>  microchip,mcp4662-503	Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (50k)
>>  microchip,mcp4662-104	Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (100k)
>> +miramems,da311		MiraMEMS DA311 3-axis 12-bit digital accelerometer
>>  national,lm63		Temperature sensor with integrated fan control
>>  national,lm75		I2C TEMP SENSOR
>>  national,lm80		Serial Interface ACPI-Compatible Microprocessor System Hardware Monitor
>> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
>> index 6236fd5..c94348f 100644
>> --- a/drivers/iio/accel/Kconfig
>> +++ b/drivers/iio/accel/Kconfig
>> @@ -52,6 +52,16 @@ config BMC150_ACCEL_SPI
>>  	tristate
>>  	select REGMAP_SPI
>>
>> +config DA311
>> +	tristate "MiraMEMS DA311 3-axis 12-bit digital accelerometer driver"
>> +	depends on I2C
>> +	help
>> +	  Say yes here to build support for the MiraMEMS DA311 3-axis 12-bit
>> +	  digital accelerometer.
>> +
>> +	  To compile this driver as a module, choose M here: the
>> +	  module will be called da311.
>> +
>>  config DMARD06
>>  	tristate "Domintech DMARD06 Digital Accelerometer Driver"
>>  	depends on OF || COMPILE_TEST
>> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
>> index 9f51559..601ca59 100644
>> --- a/drivers/iio/accel/Makefile
>> +++ b/drivers/iio/accel/Makefile
>> @@ -8,6 +8,7 @@ obj-$(CONFIG_BMA220) += bma220_spi.o
>>  obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
>>  obj-$(CONFIG_BMC150_ACCEL_I2C) += bmc150-accel-i2c.o
>>  obj-$(CONFIG_BMC150_ACCEL_SPI) += bmc150-accel-spi.o
>> +obj-$(CONFIG_DA311)	+= da311.o
>>  obj-$(CONFIG_DMARD06)	+= dmard06.o
>>  obj-$(CONFIG_DMARD09)	+= dmard09.o
>>  obj-$(CONFIG_DMARD10)	+= dmard10.o
>> diff --git a/drivers/iio/accel/da311.c b/drivers/iio/accel/da311.c
>> new file mode 100644
>> index 0000000..8c852f5
>> --- /dev/null
>> +++ b/drivers/iio/accel/da311.c
>> @@ -0,0 +1,305 @@
>> +/**
>> + * IIO driver for the MiraMEMS DA311 3-axis accelerometer
>> + *
>> + * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
>> + * Copyright (c) 2011-2013 MiraMEMS Sensing 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 DA311_CHIP_ID			0x13
>> +
>> +/*
>> + * Note register addressed go from 0 - 0x3f and then wrap.
>> + * For some reason there are 2 banks with 0 - 0x3f addresses,
>> + * rather then a single 0-0x7f bank.
>> + */
>> +
>> +/* Bank 0 regs */
>> +#define DA311_REG_BANK			0x0000
>> +#define DA311_REG_LDO_REG		0x0006
>> +#define DA311_REG_CHIP_ID		0x000f
>> +#define DA311_REG_TEMP_CFG_REG		0x001f
>> +#define DA311_REG_CTRL_REG1		0x0020
>> +#define DA311_REG_CTRL_REG3		0x0022
>> +#define DA311_REG_CTRL_REG4		0x0023
>> +#define DA311_REG_CTRL_REG5		0x0024
>> +#define DA311_REG_CTRL_REG6		0x0025
>> +#define DA311_REG_STATUS_REG		0x0027
>> +#define DA311_REG_OUT_X_L		0x0028
>> +#define DA311_REG_OUT_X_H		0x0029
>> +#define DA311_REG_OUT_Y_L		0x002a
>> +#define DA311_REG_OUT_Y_H		0x002b
>> +#define DA311_REG_OUT_Z_L		0x002c
>> +#define DA311_REG_OUT_Z_H		0x002d
>> +#define DA311_REG_INT1_CFG		0x0030
>> +#define DA311_REG_INT1_SRC		0x0031
>> +#define DA311_REG_INT1_THS		0x0032
>> +#define DA311_REG_INT1_DURATION		0x0033
>> +#define DA311_REG_INT2_CFG		0x0034
>> +#define DA311_REG_INT2_SRC		0x0035
>> +#define DA311_REG_INT2_THS		0x0036
>> +#define DA311_REG_INT2_DURATION		0x0037
>> +#define DA311_REG_CLICK_CFG		0x0038
>> +#define DA311_REG_CLICK_SRC		0x0039
>> +#define DA311_REG_CLICK_THS		0x003a
>> +#define DA311_REG_TIME_LIMIT		0x003b
>> +#define DA311_REG_TIME_LATENCY		0x003c
>> +#define DA311_REG_TIME_WINDOW		0x003d
>> +
>> +/* Bank 1 regs */
>> +#define DA311_REG_SOFT_RESET		0x0105
>> +#define DA311_REG_OTP_XOFF_L		0x0110
>> +#define DA311_REG_OTP_XOFF_H		0x0111
>> +#define DA311_REG_OTP_YOFF_L		0x0112
>> +#define DA311_REG_OTP_YOFF_H		0x0113
>> +#define DA311_REG_OTP_ZOFF_L		0x0114
>> +#define DA311_REG_OTP_ZOFF_H		0x0115
>> +#define DA311_REG_OTP_XSO		0x0116
>> +#define DA311_REG_OTP_YSO		0x0117
>> +#define DA311_REG_OTP_ZSO		0x0118
>> +#define DA311_REG_OTP_TRIM_OSC		0x011b
>> +#define DA311_REG_LPF_ABSOLUTE		0x011c
>> +#define DA311_REG_TEMP_OFF1		0x0127
>> +#define DA311_REG_TEMP_OFF2		0x0128
>> +#define DA311_REG_TEMP_OFF3		0x0129
>> +#define DA311_REG_OTP_TRIM_THERM_H	0x011a
>> +
>> +/*
>> + * a value of + or -1024 corresponds to + or - 1G
>> + * scale = 1 / 1024 = 0.000976562
>> + */
>> +
>> +static const int da311_nscale = 976562;
>> +
>> +#define DA311_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 da311_channels[] = {
>> +	/* | 0x80 comes from the android driver */
>> +	DA311_CHANNEL(DA311_REG_OUT_X_L | 0x80, X),
>> +	DA311_CHANNEL(DA311_REG_OUT_Y_L | 0x80, Y),
>> +	DA311_CHANNEL(DA311_REG_OUT_Z_L | 0x80, Z),
>> +};
>> +
>> +struct da311_data {
>> +	struct i2c_client *client;
>> +};
>> +
>> +static int da311_register_mask_write(struct i2c_client *client, u16 addr,
>> +				     u8 mask, u8 data)
>> +{
>> +	int ret;
>> +	u8 tmp_data = 0;
>> +
>> +	if (addr & 0xff00) {
>> +		/* Select bank 1 */
>> +		ret = i2c_smbus_write_byte_data(client, DA311_REG_BANK, 0x01);
>> +		if (ret < 0)
>> +			return ret;
>> +	}
>> +
>> +	if (mask != 0xff) {
>> +		ret = i2c_smbus_read_byte_data(client, addr);
>> +		if (ret < 0)
>> +			return ret;
>> +		tmp_data = ret;
>> +	}
>> +
>> +	tmp_data &= ~mask;
>> +	tmp_data |= data & mask;
>> +	ret = i2c_smbus_write_byte_data(client, addr & 0xff, tmp_data);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	if (addr & 0xff00) {
>> +		/* Back to bank 0 */
>> +		ret = i2c_smbus_write_byte_data(client, DA311_REG_BANK, 0x00);
>> +		if (ret < 0)
>> +			return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +/* Init sequence taken from the android driver */
>> +static int da311_reset(struct i2c_client *client)
>> +{
>> +	const struct {
>> +		u16 addr;
>> +		u8 mask;
>> +		u8 data;
>> +	} init_data[] = {
>> +		{ DA311_REG_TEMP_CFG_REG,       0xff,   0x08 },
>> +		{ DA311_REG_CTRL_REG5,          0xff,   0x80 },
>> +		{ DA311_REG_CTRL_REG4,          0x30,   0x00 },
>> +		{ DA311_REG_CTRL_REG1,          0xff,   0x6f },
>> +		{ DA311_REG_TEMP_CFG_REG,       0xff,   0x88 },
>> +		{ DA311_REG_LDO_REG,            0xff,   0x02 },
>> +		{ DA311_REG_OTP_TRIM_OSC,       0xff,   0x27 },
>> +		{ DA311_REG_LPF_ABSOLUTE,       0xff,   0x30 },
>> +		{ DA311_REG_TEMP_OFF1,          0xff,   0x3f },
>> +		{ DA311_REG_TEMP_OFF2,          0xff,   0xff },
>> +		{ DA311_REG_TEMP_OFF3,          0xff,   0x0f },
> Nice ;)  Not much we can do about this without a datasheet. Ah well.

Yes, ah well indeed.

>> +	};
>> +	int i, ret;
>> +
>> +	/* Reset */
>> +	ret = da311_register_mask_write(client, DA311_REG_SOFT_RESET,
>> +					0xff, 0xaa);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	for (i = 0; i < ARRAY_SIZE(init_data); i++) {
>> +		ret = da311_register_mask_write(client,
>> +						init_data[i].addr,
>> +						init_data[i].mask,
>> +						init_data[i].data);
>> +		if (ret < 0)
>> +			return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int da311_enable(struct i2c_client *client, bool enable)
>> +{
>> +	u8 data = enable ? 0x00 : 0x20;
> This feels ever so slightly like a magic number that ought to be
> a define rather than inline.  Probably using BIT(5) to define it.
> I guess this would be more obvious if we had a datasheet to tell us
> what to call it etc.

The problem is we've no clue what to call the define, so I would
prefer to just keep this as is.

>> +
>> +	return da311_register_mask_write(client, DA311_REG_TEMP_CFG_REG,
>> +					 0x20, data);
>> +}
>> +
>> +static int da311_read_raw(struct iio_dev *indio_dev,
>> +				struct iio_chan_spec const *chan,
>> +				int *val, int *val2, long mask)
>> +{
>> +	struct da311_data *data = iio_priv(indio_dev);
>> +	int ret;
>> +
>> +	switch (mask) {
>> +	case IIO_CHAN_INFO_RAW:
>> +		ret = i2c_smbus_read_word_data(data->client, chan->address);
>> +		if (ret < 0)
>> +			return ret;
>> +		/*
>> +		 * Values are 12 bits, stored as 16 bits with the 4
>> +		 * least significant bits always 0.
>> +		 */
>> +		*val = ((short)le16_to_cpu(ret)) >> 4;
>> +		return IIO_VAL_INT;
>> +	case IIO_CHAN_INFO_SCALE:
>> +		*val = 0;
>> +		*val2 = da311_nscale;
>> +		return IIO_VAL_INT_PLUS_NANO;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +}
>> +
>> +static const struct iio_info da311_info = {
>> +	.driver_module	= THIS_MODULE,
>> +	.read_raw	= da311_read_raw,
>> +};
>> +
>> +static int da311_probe(struct i2c_client *client,
>> +			const struct i2c_device_id *id)
>> +{
>> +	int ret;
>> +	struct iio_dev *indio_dev;
>> +	struct da311_data *data;
>> +
>> +	ret = i2c_smbus_read_byte_data(client, DA311_REG_CHIP_ID);
>> +	if (ret != DA311_CHIP_ID)
>> +		return (ret < 0) ? ret : -ENODEV;
>> +
>> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
>> +	if (!indio_dev)
>> +		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 = &da311_info;
>> +	indio_dev->name = "da311";
>> +	indio_dev->modes = INDIO_DIRECT_MODE;
>> +	indio_dev->channels = da311_channels;
>> +	indio_dev->num_channels = ARRAY_SIZE(da311_channels);
>> +
>> +	ret = da311_reset(client);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	ret = da311_enable(client, true);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	ret = iio_device_register(indio_dev);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "device_register failed\n");
>> +		da311_enable(client, false);
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int da311_remove(struct i2c_client *client)
>> +{
>> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
>> +
>> +	iio_device_unregister(indio_dev);
>> +
>> +	return da311_enable(client, false);
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int da311_suspend(struct device *dev)
>> +{
>> +	return da311_enable(to_i2c_client(dev), false);
>> +}
>> +
>> +static int da311_resume(struct device *dev)
>> +{
>> +	return da311_enable(to_i2c_client(dev), true);
>> +}
>> +#endif
> I'd just go with the __maybe_unused option rather than the
> define protection.

Hmm, almost all the drivers I've looked at / know of use
#ifdef here, including the ones under iio/accel.

So I would also prefer to just keep this as is.

Let me know if you want a v3 with anything changed.

Thanks & Regards,

Hans


>> +
>> +static SIMPLE_DEV_PM_OPS(da311_pm_ops, da311_suspend, da311_resume);
>> +
>> +static const struct i2c_device_id da311_i2c_id[] = {
>> +	{"da311", 0},
>> +	{}
>> +};
>> +MODULE_DEVICE_TABLE(i2c, da311_i2c_id);
>> +
>> +static struct i2c_driver da311_driver = {
>> +	.driver = {
>> +		.name = "da311",
>> +		.pm = &da311_pm_ops,
>> +	},
>> +	.probe		= da311_probe,
>> +	.remove		= da311_remove,
>> +	.id_table	= da311_i2c_id,
>> +};
>> +
>> +module_i2c_driver(da311_driver);
>> +
>> +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
>> +MODULE_DESCRIPTION("MiraMEMS DA311 3-Axis Accelerometer driver");
>> +MODULE_LICENSE("GPL v2");
>>
>