diff options
Diffstat (limited to 'drivers/iio/accel/dmard10.c')
| -rw-r--r-- | drivers/iio/accel/dmard10.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/drivers/iio/accel/dmard10.c b/drivers/iio/accel/dmard10.c new file mode 100644 index 000000000..9518ea001 --- /dev/null +++ b/drivers/iio/accel/dmard10.c @@ -0,0 +1,265 @@ +/** + * 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 = 9.81 / 128 = 0.076640625 + */ + +static const int dmard10_nscale = 76640625; + +#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 = { + .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"); |