/** * 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 = { .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");