iio: accel: Add driver for the MiraMEMS DA311 3-axis 12-bit digital accelerometer

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.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Documentation/devicetree/bindings/i2c/trivial-devices.txt

@@ -125,6 +125,7 @@ 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

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

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

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 = 9.81 / 1024 = 0.009580078
+ */
+
+static const int da311_nscale = 9580078;
+
+#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 },
+	};
+	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;
+
+	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)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
+
+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");