iio: accel: Add support for Sensortek STK8312
Minimal implementation of an IIO driver for the Sensortek STK8312 3-axis accelerometer. Datasheet: http://www.syi-group.com/uploadpic/data/201361817562681623.pdf Includes: - ACPI support; - read_raw for x,y,z axes; - reading and setting the scale (range) parameter. - power management Signed-off-by: Tiberiu Breana <tiberiu.a.breana@intel.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Tiberiu Breana
Jonathan Cameron
parent
c16bff4844
commit
90bad33acb
@ -136,4 +136,15 @@ config MMA9553
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To compile this driver as a module, choose M here: the module
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will be called mma9553.
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config STK8312
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tristate "Sensortek STK8312 3-Axis Accelerometer Driver"
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depends on I2C
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help
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Say yes here to get support for the Sensortek STK8312 3-axis
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accelerometer.
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Choosing M will build the driver as a module. If so, the module
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will be called stk8312.
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endmenu
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@ -14,6 +14,8 @@ obj-$(CONFIG_MMA9551_CORE) += mma9551_core.o
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obj-$(CONFIG_MMA9551) += mma9551.o
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obj-$(CONFIG_MMA9553) += mma9553.o
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obj-$(CONFIG_STK8312) += stk8312.o
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obj-$(CONFIG_IIO_SSP_SENSORS_COMMONS) += ssp_accel_sensor.o
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obj-$(CONFIG_IIO_ST_ACCEL_3AXIS) += st_accel.o
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390
drivers/iio/accel/stk8312.c
Normal file
390
drivers/iio/accel/stk8312.c
Normal file
@ -0,0 +1,390 @@
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/**
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* Sensortek STK8312 3-Axis Accelerometer
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*
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* Copyright (c) 2015, Intel Corporation.
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*
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* This file is subject to the terms and conditions of version 2 of
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* the GNU General Public License. See the file COPYING in the main
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* directory of this archive for more details.
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*
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* IIO driver for STK8312; 7-bit I2C address: 0x3D.
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*/
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#include <linux/acpi.h>
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#include <linux/i2c.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/delay.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#define STK8312_REG_XOUT 0x00
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#define STK8312_REG_YOUT 0x01
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#define STK8312_REG_ZOUT 0x02
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#define STK8312_REG_MODE 0x07
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#define STK8312_REG_STH 0x13
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#define STK8312_REG_RESET 0x20
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#define STK8312_REG_AFECTRL 0x24
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#define STK8312_REG_OTPADDR 0x3D
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#define STK8312_REG_OTPDATA 0x3E
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#define STK8312_REG_OTPCTRL 0x3F
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#define STK8312_MODE_ACTIVE 1
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#define STK8312_MODE_STANDBY 0
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#define STK8312_MODE_MASK 0x01
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#define STK8312_RNG_MASK 0xC0
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#define STK8312_RNG_SHIFT 6
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#define STK8312_READ_RETRIES 16
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#define STK8312_DRIVER_NAME "stk8312"
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/*
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* The accelerometer has two measurement ranges:
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*
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* -6g - +6g (8-bit, signed)
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* -16g - +16g (8-bit, signed)
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*
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* scale1 = (6 + 6) * 9.81 / (2^8 - 1) = 0.4616
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* scale2 = (16 + 16) * 9.81 / (2^8 - 1) = 1.2311
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*/
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#define STK8312_SCALE_AVAIL "0.4616 1.2311"
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static const int stk8312_scale_table[][2] = {
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{0, 461600}, {1, 231100}
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};
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#define STK8312_ACCEL_CHANNEL(reg, axis) { \
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.type = IIO_ACCEL, \
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.address = reg, \
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.modified = 1, \
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.channel2 = IIO_MOD_##axis, \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
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}
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static const struct iio_chan_spec stk8312_channels[] = {
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STK8312_ACCEL_CHANNEL(STK8312_REG_XOUT, X),
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STK8312_ACCEL_CHANNEL(STK8312_REG_YOUT, Y),
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STK8312_ACCEL_CHANNEL(STK8312_REG_ZOUT, Z),
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};
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struct stk8312_data {
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struct i2c_client *client;
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struct mutex lock;
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int range;
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u8 mode;
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};
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static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
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static struct attribute *stk8312_attributes[] = {
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&iio_const_attr_in_accel_scale_available.dev_attr.attr,
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NULL,
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};
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static const struct attribute_group stk8312_attribute_group = {
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.attrs = stk8312_attributes
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};
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static int stk8312_otp_init(struct stk8312_data *data)
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{
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int ret;
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int count = 10;
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struct i2c_client *client = data->client;
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ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);
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if (ret < 0)
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goto exit_err;
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ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);
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if (ret < 0)
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goto exit_err;
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do {
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usleep_range(1000, 5000);
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ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);
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if (ret < 0)
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goto exit_err;
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count--;
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} while (!(ret & 0x80) && count > 0);
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if (count == 0)
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goto exit_err;
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ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
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if (ret < 0)
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goto exit_err;
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ret = i2c_smbus_write_byte_data(data->client,
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STK8312_REG_AFECTRL, ret);
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if (ret < 0)
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goto exit_err;
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msleep(150);
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return ret;
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exit_err:
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dev_err(&client->dev, "failed to initialize sensor\n");
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return ret;
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}
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static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
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{
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int ret;
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u8 masked_reg;
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struct i2c_client *client = data->client;
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if (mode > 1)
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return -EINVAL;
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else if (mode == data->mode)
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return 0;
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ret = i2c_smbus_read_byte_data(client, STK8312_REG_MODE);
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if (ret < 0) {
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dev_err(&client->dev, "failed to change sensor mode\n");
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return ret;
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}
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masked_reg = ret & (~STK8312_MODE_MASK);
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masked_reg |= mode;
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ret = i2c_smbus_write_byte_data(client,
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STK8312_REG_MODE, masked_reg);
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if (ret < 0) {
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dev_err(&client->dev, "failed to change sensor mode\n");
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return ret;
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}
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data->mode = mode;
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if (mode == STK8312_MODE_ACTIVE) {
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/* Need to run OTP sequence before entering active mode */
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usleep_range(1000, 5000);
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ret = stk8312_otp_init(data);
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}
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return ret;
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}
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static int stk8312_set_range(struct stk8312_data *data, u8 range)
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{
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int ret;
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u8 masked_reg;
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u8 mode;
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struct i2c_client *client = data->client;
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if (range != 1 && range != 2)
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return -EINVAL;
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else if (range == data->range)
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return 0;
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mode = data->mode;
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/* We need to go in standby mode to modify registers */
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ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
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if (ret < 0)
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return ret;
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ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
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if (ret < 0) {
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dev_err(&client->dev, "failed to change sensor range\n");
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return ret;
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}
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masked_reg = ret & (~STK8312_RNG_MASK);
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masked_reg |= range << STK8312_RNG_SHIFT;
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ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
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if (ret < 0)
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dev_err(&client->dev, "failed to change sensor range\n");
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else
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data->range = range;
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return stk8312_set_mode(data, mode);
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}
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static int stk8312_read_accel(struct stk8312_data *data, u8 address)
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{
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int ret;
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struct i2c_client *client = data->client;
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if (address > 2)
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return -EINVAL;
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ret = i2c_smbus_read_byte_data(client, address);
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if (ret < 0) {
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dev_err(&client->dev, "register read failed\n");
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return ret;
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}
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return sign_extend32(ret, 7);
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}
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static int stk8312_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct stk8312_data *data = iio_priv(indio_dev);
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if (chan->type != IIO_ACCEL)
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return -EINVAL;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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mutex_lock(&data->lock);
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*val = stk8312_read_accel(data, chan->address);
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mutex_unlock(&data->lock);
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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*val = stk8312_scale_table[data->range - 1][0];
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*val2 = stk8312_scale_table[data->range - 1][1];
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return IIO_VAL_INT_PLUS_MICRO;
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}
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return -EINVAL;
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}
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static int stk8312_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val, int val2, long mask)
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{
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int i;
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int index = -1;
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int ret;
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struct stk8312_data *data = iio_priv(indio_dev);
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switch (mask) {
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case IIO_CHAN_INFO_SCALE:
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for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
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if (val == stk8312_scale_table[i][0] &&
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val2 == stk8312_scale_table[i][1]) {
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index = i + 1;
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break;
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}
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if (index < 0)
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return -EINVAL;
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mutex_lock(&data->lock);
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ret = stk8312_set_range(data, index);
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mutex_unlock(&data->lock);
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return ret;
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}
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return -EINVAL;
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}
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static const struct iio_info stk8312_info = {
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.driver_module = THIS_MODULE,
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.read_raw = stk8312_read_raw,
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.write_raw = stk8312_write_raw,
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.attrs = &stk8312_attribute_group,
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};
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static int stk8312_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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int ret;
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struct iio_dev *indio_dev;
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struct stk8312_data *data;
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
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if (!indio_dev) {
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dev_err(&client->dev, "iio allocation failed!\n");
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return -ENOMEM;
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}
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data = iio_priv(indio_dev);
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data->client = client;
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i2c_set_clientdata(client, indio_dev);
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mutex_init(&data->lock);
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indio_dev->dev.parent = &client->dev;
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indio_dev->info = &stk8312_info;
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indio_dev->name = STK8312_DRIVER_NAME;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = stk8312_channels;
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indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);
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/* A software reset is recommended at power-on */
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ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);
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if (ret < 0) {
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dev_err(&client->dev, "failed to reset sensor\n");
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return ret;
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}
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ret = stk8312_set_range(data, 1);
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if (ret < 0)
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return ret;
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ret = stk8312_set_mode(data, STK8312_MODE_ACTIVE);
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if (ret < 0)
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return ret;
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ret = iio_device_register(indio_dev);
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if (ret < 0) {
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dev_err(&client->dev, "device_register failed\n");
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stk8312_set_mode(data, STK8312_MODE_STANDBY);
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}
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return ret;
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}
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static int stk8312_remove(struct i2c_client *client)
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{
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struct iio_dev *indio_dev = i2c_get_clientdata(client);
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iio_device_unregister(indio_dev);
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return stk8312_set_mode(iio_priv(indio_dev), STK8312_MODE_STANDBY);
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}
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#ifdef CONFIG_PM_SLEEP
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static int stk8312_suspend(struct device *dev)
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{
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struct stk8312_data *data;
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data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
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return stk8312_set_mode(data, STK8312_MODE_STANDBY);
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}
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static int stk8312_resume(struct device *dev)
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{
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struct stk8312_data *data;
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data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
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return stk8312_set_mode(data, STK8312_MODE_ACTIVE);
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}
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static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
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#define STK8312_PM_OPS (&stk8312_pm_ops)
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#else
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#define STK8312_PM_OPS NULL
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#endif
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static const struct i2c_device_id stk8312_i2c_id[] = {
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{"STK8312", 0},
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{}
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};
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static const struct acpi_device_id stk8312_acpi_id[] = {
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{"STK8312", 0},
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{}
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};
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MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);
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static struct i2c_driver stk8312_driver = {
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.driver = {
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.name = "stk8312",
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.pm = STK8312_PM_OPS,
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.acpi_match_table = ACPI_PTR(stk8312_acpi_id),
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},
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.probe = stk8312_probe,
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.remove = stk8312_remove,
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.id_table = stk8312_i2c_id,
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};
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module_i2c_driver(stk8312_driver);
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MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
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MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
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MODULE_LICENSE("GPL v2");
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