1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 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., Ltd 7 */ 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 0x00 16 #define DMARD10_REG_AFEM 0x0c 17 #define DMARD10_REG_STADR 0x12 18 #define DMARD10_REG_STAINT 0x1c 19 #define DMARD10_REG_MISC2 0x1f 20 #define DMARD10_REG_PD 0x21 21 22 #define DMARD10_MODE_OFF 0x00 23 #define DMARD10_MODE_STANDBY 0x02 24 #define DMARD10_MODE_ACTIVE 0x06 25 #define DMARD10_MODE_READ_OTP 0x12 26 #define DMARD10_MODE_RESET_DATA_PATH 0x82 27 28 /* AFEN set 1, ATM[2:0]=b'000 (normal), EN_Z/Y/X/T=1 */ 29 #define DMARD10_VALUE_AFEM_AFEN_NORMAL 0x8f 30 /* ODR[3:0]=b'0111 (100Hz), CCK[3:0]=b'0100 (204.8kHZ) */ 31 #define DMARD10_VALUE_CKSEL_ODR_100_204 0x74 32 /* INTC[6:5]=b'00 */ 33 #define DMARD10_VALUE_INTC 0x00 34 /* TAP1/TAP2 Average 2 */ 35 #define DMARD10_VALUE_TAPNS_AVE_2 0x11 36 37 #define DMARD10_VALUE_STADR 0x55 38 #define DMARD10_VALUE_STAINT 0xaa 39 #define DMARD10_VALUE_MISC2_OSCA_EN 0x08 40 #define DMARD10_VALUE_PD_RST 0x52 41 42 /* Offsets into the buffer read in dmard10_read_raw() */ 43 #define DMARD10_X_OFFSET 1 44 #define DMARD10_Y_OFFSET 2 45 #define DMARD10_Z_OFFSET 3 46 47 /* 48 * a value of + or -128 corresponds to + or - 1G 49 * scale = 9.81 / 128 = 0.076640625 50 */ 51 52 static 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 63 static 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 69 struct dmard10_data { 70 struct i2c_client *client; 71 }; 72 73 /* Init sequence taken from the android driver */ 74 static 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 mode 88 */ 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 */ 127 static 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 } 137 138 static 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 to 150 * 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 } 168 169 static const struct iio_info dmard10_info = { 170 .read_raw = dmard10_read_raw, 171 }; 172 173 static void dmard10_shutdown_cleanup(void *client) 174 { 175 dmard10_shutdown(client); 176 } 177 178 static 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 } 219 220 static int dmard10_suspend(struct device *dev) 221 { 222 return dmard10_shutdown(to_i2c_client(dev)); 223 } 224 225 static int dmard10_resume(struct device *dev) 226 { 227 return dmard10_reset(to_i2c_client(dev)); 228 } 229 230 static DEFINE_SIMPLE_DEV_PM_OPS(dmard10_pm_ops, dmard10_suspend, 231 dmard10_resume); 232 233 static const struct i2c_device_id dmard10_i2c_id[] = { 234 {"dmard10", 0}, 235 {} 236 }; 237 MODULE_DEVICE_TABLE(i2c, dmard10_i2c_id); 238 239 static 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 }; 247 248 module_i2c_driver(dmard10_driver); 249 250 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 251 MODULE_DESCRIPTION("Domintech ARD10 3-Axis Accelerometer driver"); 252 MODULE_LICENSE("GPL v2"); 253