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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * IIO driver for the 3-axis accelerometer Domintech ARD10.4 *5 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>6 * Copyright (c) 2012 Domintech Technology Co., Ltd7 */8 9#include <linux/module.h>10#include <linux/i2c.h>11#include <linux/iio/iio.h>12#include <linux/iio/sysfs.h>13#include <linux/byteorder/generic.h>14 15#define DMARD10_REG_ACTR 0x0016#define DMARD10_REG_AFEM 0x0c17#define DMARD10_REG_STADR 0x1218#define DMARD10_REG_STAINT 0x1c19#define DMARD10_REG_MISC2 0x1f20#define DMARD10_REG_PD 0x2121 22#define DMARD10_MODE_OFF 0x0023#define DMARD10_MODE_STANDBY 0x0224#define DMARD10_MODE_ACTIVE 0x0625#define DMARD10_MODE_READ_OTP 0x1226#define DMARD10_MODE_RESET_DATA_PATH 0x8227 28/* AFEN set 1, ATM[2:0]=b'000 (normal), EN_Z/Y/X/T=1 */29#define DMARD10_VALUE_AFEM_AFEN_NORMAL 0x8f30/* ODR[3:0]=b'0111 (100Hz), CCK[3:0]=b'0100 (204.8kHZ) */31#define DMARD10_VALUE_CKSEL_ODR_100_204 0x7432/* INTC[6:5]=b'00 */33#define DMARD10_VALUE_INTC 0x0034/* TAP1/TAP2 Average 2 */35#define DMARD10_VALUE_TAPNS_AVE_2 0x1136 37#define DMARD10_VALUE_STADR 0x5538#define DMARD10_VALUE_STAINT 0xaa39#define DMARD10_VALUE_MISC2_OSCA_EN 0x0840#define DMARD10_VALUE_PD_RST 0x5241 42/* Offsets into the buffer read in dmard10_read_raw() */43#define DMARD10_X_OFFSET 144#define DMARD10_Y_OFFSET 245#define DMARD10_Z_OFFSET 346 47/*48 * a value of + or -128 corresponds to + or - 1G49 * scale = 9.81 / 128 = 0.07664062550 */51 52static const int dmard10_nscale = 76640625;53 54#define DMARD10_CHANNEL(reg, axis) { \55 .type = IIO_ACCEL, \56 .address = reg, \57 .modified = 1, \58 .channel2 = IIO_MOD_##axis, \59 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \60 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \61}62 63static const struct iio_chan_spec dmard10_channels[] = {64 DMARD10_CHANNEL(DMARD10_X_OFFSET, X),65 DMARD10_CHANNEL(DMARD10_Y_OFFSET, Y),66 DMARD10_CHANNEL(DMARD10_Z_OFFSET, Z),67};68 69struct dmard10_data {70 struct i2c_client *client;71};72 73/* Init sequence taken from the android driver */74static int dmard10_reset(struct i2c_client *client)75{76 unsigned char buffer[7];77 int ret;78 79 /* 1. Powerdown reset */80 ret = i2c_smbus_write_byte_data(client, DMARD10_REG_PD,81 DMARD10_VALUE_PD_RST);82 if (ret < 0)83 return ret;84 85 /*86 * 2. ACTR => Standby mode => Download OTP to parameter reg =>87 * Standby mode => Reset data path => Standby mode88 */89 buffer[0] = DMARD10_REG_ACTR;90 buffer[1] = DMARD10_MODE_STANDBY;91 buffer[2] = DMARD10_MODE_READ_OTP;92 buffer[3] = DMARD10_MODE_STANDBY;93 buffer[4] = DMARD10_MODE_RESET_DATA_PATH;94 buffer[5] = DMARD10_MODE_STANDBY;95 ret = i2c_master_send(client, buffer, 6);96 if (ret < 0)97 return ret;98 99 /* 3. OSCA_EN = 1, TSTO = b'000 (INT1 = normal, TEST0 = normal) */100 ret = i2c_smbus_write_byte_data(client, DMARD10_REG_MISC2,101 DMARD10_VALUE_MISC2_OSCA_EN);102 if (ret < 0)103 return ret;104 105 /* 4. AFEN = 1 (AFE will powerdown after ADC) */106 buffer[0] = DMARD10_REG_AFEM;107 buffer[1] = DMARD10_VALUE_AFEM_AFEN_NORMAL;108 buffer[2] = DMARD10_VALUE_CKSEL_ODR_100_204;109 buffer[3] = DMARD10_VALUE_INTC;110 buffer[4] = DMARD10_VALUE_TAPNS_AVE_2;111 buffer[5] = 0x00; /* DLYC, no delay timing */112 buffer[6] = 0x07; /* INTD=1 push-pull, INTA=1 active high, AUTOT=1 */113 ret = i2c_master_send(client, buffer, 7);114 if (ret < 0)115 return ret;116 117 /* 5. Activation mode */118 ret = i2c_smbus_write_byte_data(client, DMARD10_REG_ACTR,119 DMARD10_MODE_ACTIVE);120 if (ret < 0)121 return ret;122 123 return 0;124}125 126/* Shutdown sequence taken from the android driver */127static int dmard10_shutdown(struct i2c_client *client)128{129 unsigned char buffer[3];130 131 buffer[0] = DMARD10_REG_ACTR;132 buffer[1] = DMARD10_MODE_STANDBY;133 buffer[2] = DMARD10_MODE_OFF;134 135 return i2c_master_send(client, buffer, 3);136}137 138static int dmard10_read_raw(struct iio_dev *indio_dev,139 struct iio_chan_spec const *chan,140 int *val, int *val2, long mask)141{142 struct dmard10_data *data = iio_priv(indio_dev);143 __le16 buf[4];144 int ret;145 146 switch (mask) {147 case IIO_CHAN_INFO_RAW:148 /*149 * Read 8 bytes starting at the REG_STADR register, trying to150 * read the individual X, Y, Z registers will always read 0.151 */152 ret = i2c_smbus_read_i2c_block_data(data->client,153 DMARD10_REG_STADR,154 sizeof(buf), (u8 *)buf);155 if (ret < 0)156 return ret;157 ret = le16_to_cpu(buf[chan->address]);158 *val = sign_extend32(ret, 12);159 return IIO_VAL_INT;160 case IIO_CHAN_INFO_SCALE:161 *val = 0;162 *val2 = dmard10_nscale;163 return IIO_VAL_INT_PLUS_NANO;164 default:165 return -EINVAL;166 }167}168 169static const struct iio_info dmard10_info = {170 .read_raw = dmard10_read_raw,171};172 173static void dmard10_shutdown_cleanup(void *client)174{175 dmard10_shutdown(client);176}177 178static int dmard10_probe(struct i2c_client *client)179{180 int ret;181 struct iio_dev *indio_dev;182 struct dmard10_data *data;183 184 /* These 2 registers have special POR reset values used for id */185 ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STADR);186 if (ret != DMARD10_VALUE_STADR)187 return (ret < 0) ? ret : -ENODEV;188 189 ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STAINT);190 if (ret != DMARD10_VALUE_STAINT)191 return (ret < 0) ? ret : -ENODEV;192 193 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));194 if (!indio_dev) {195 dev_err(&client->dev, "iio allocation failed!\n");196 return -ENOMEM;197 }198 199 data = iio_priv(indio_dev);200 data->client = client;201 202 indio_dev->info = &dmard10_info;203 indio_dev->name = "dmard10";204 indio_dev->modes = INDIO_DIRECT_MODE;205 indio_dev->channels = dmard10_channels;206 indio_dev->num_channels = ARRAY_SIZE(dmard10_channels);207 208 ret = dmard10_reset(client);209 if (ret < 0)210 return ret;211 212 ret = devm_add_action_or_reset(&client->dev, dmard10_shutdown_cleanup,213 client);214 if (ret)215 return ret;216 217 return devm_iio_device_register(&client->dev, indio_dev);218}219 220static int dmard10_suspend(struct device *dev)221{222 return dmard10_shutdown(to_i2c_client(dev));223}224 225static int dmard10_resume(struct device *dev)226{227 return dmard10_reset(to_i2c_client(dev));228}229 230static DEFINE_SIMPLE_DEV_PM_OPS(dmard10_pm_ops, dmard10_suspend,231 dmard10_resume);232 233static const struct i2c_device_id dmard10_i2c_id[] = {234 { "dmard10" },235 {}236};237MODULE_DEVICE_TABLE(i2c, dmard10_i2c_id);238 239static struct i2c_driver dmard10_driver = {240 .driver = {241 .name = "dmard10",242 .pm = pm_sleep_ptr(&dmard10_pm_ops),243 },244 .probe = dmard10_probe,245 .id_table = dmard10_i2c_id,246};247 248module_i2c_driver(dmard10_driver);249 250MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");251MODULE_DESCRIPTION("Domintech ARD10 3-Axis Accelerometer driver");252MODULE_LICENSE("GPL v2");253