1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2019 TDK-InvenSense, Inc. 4 */ 5 6 #include <linux/kernel.h> 7 #include <linux/device.h> 8 #include <linux/string.h> 9 10 #include "inv_mpu_aux.h" 11 #include "inv_mpu_iio.h" 12 #include "inv_mpu_magn.h" 13 14 /* 15 * MPU9xxx magnetometer are AKM chips on I2C aux bus 16 * MPU9150 is AK8975 17 * MPU9250 is AK8963 18 */ 19 #define INV_MPU_MAGN_I2C_ADDR 0x0C 20 21 #define INV_MPU_MAGN_REG_WIA 0x00 22 #define INV_MPU_MAGN_BITS_WIA 0x48 23 24 #define INV_MPU_MAGN_REG_ST1 0x02 25 #define INV_MPU_MAGN_BIT_DRDY 0x01 26 #define INV_MPU_MAGN_BIT_DOR 0x02 27 28 #define INV_MPU_MAGN_REG_DATA 0x03 29 30 #define INV_MPU_MAGN_REG_ST2 0x09 31 #define INV_MPU_MAGN_BIT_HOFL 0x08 32 #define INV_MPU_MAGN_BIT_BITM 0x10 33 34 #define INV_MPU_MAGN_REG_CNTL1 0x0A 35 #define INV_MPU_MAGN_BITS_MODE_PWDN 0x00 36 #define INV_MPU_MAGN_BITS_MODE_SINGLE 0x01 37 #define INV_MPU_MAGN_BITS_MODE_FUSE 0x0F 38 #define INV_MPU9250_MAGN_BIT_OUTPUT_BIT 0x10 39 40 #define INV_MPU9250_MAGN_REG_CNTL2 0x0B 41 #define INV_MPU9250_MAGN_BIT_SRST 0x01 42 43 #define INV_MPU_MAGN_REG_ASAX 0x10 44 #define INV_MPU_MAGN_REG_ASAY 0x11 45 #define INV_MPU_MAGN_REG_ASAZ 0x12 46 47 static bool inv_magn_supported(const struct inv_mpu6050_state *st) 48 { 49 switch (st->chip_type) { 50 case INV_MPU9150: 51 case INV_MPU9250: 52 case INV_MPU9255: 53 return true; 54 default: 55 return false; 56 } 57 } 58 59 /* init magnetometer chip */ 60 static int inv_magn_init(struct inv_mpu6050_state *st) 61 { 62 uint8_t val; 63 uint8_t asa[3]; 64 int32_t sensitivity; 65 int ret; 66 67 /* check whoami */ 68 ret = inv_mpu_aux_read(st, INV_MPU_MAGN_I2C_ADDR, INV_MPU_MAGN_REG_WIA, 69 &val, sizeof(val)); 70 if (ret) 71 return ret; 72 if (val != INV_MPU_MAGN_BITS_WIA) 73 return -ENODEV; 74 75 /* software reset for MPU925x only */ 76 switch (st->chip_type) { 77 case INV_MPU9250: 78 case INV_MPU9255: 79 ret = inv_mpu_aux_write(st, INV_MPU_MAGN_I2C_ADDR, 80 INV_MPU9250_MAGN_REG_CNTL2, 81 INV_MPU9250_MAGN_BIT_SRST); 82 if (ret) 83 return ret; 84 break; 85 default: 86 break; 87 } 88 89 /* read fuse ROM data */ 90 ret = inv_mpu_aux_write(st, INV_MPU_MAGN_I2C_ADDR, 91 INV_MPU_MAGN_REG_CNTL1, 92 INV_MPU_MAGN_BITS_MODE_FUSE); 93 if (ret) 94 return ret; 95 96 ret = inv_mpu_aux_read(st, INV_MPU_MAGN_I2C_ADDR, INV_MPU_MAGN_REG_ASAX, 97 asa, sizeof(asa)); 98 if (ret) 99 return ret; 100 101 /* switch back to power-down */ 102 ret = inv_mpu_aux_write(st, INV_MPU_MAGN_I2C_ADDR, 103 INV_MPU_MAGN_REG_CNTL1, 104 INV_MPU_MAGN_BITS_MODE_PWDN); 105 if (ret) 106 return ret; 107 108 /* 109 * Sensor sentivity 110 * 1 uT = 0.01 G and value is in micron (1e6) 111 * sensitvity = x uT * 0.01 * 1e6 112 */ 113 switch (st->chip_type) { 114 case INV_MPU9150: 115 /* sensor sensitivity is 0.3 uT */ 116 sensitivity = 3000; 117 break; 118 case INV_MPU9250: 119 case INV_MPU9255: 120 /* sensor sensitivity in 16 bits mode: 0.15 uT */ 121 sensitivity = 1500; 122 break; 123 default: 124 return -EINVAL; 125 } 126 127 /* 128 * Sensitivity adjustement and scale to Gauss 129 * 130 * Hadj = H * (((ASA - 128) * 0.5 / 128) + 1) 131 * Factor simplification: 132 * Hadj = H * ((ASA + 128) / 256) 133 * 134 * raw_to_gauss = Hadj * sensitivity 135 */ 136 st->magn_raw_to_gauss[0] = (((int32_t)asa[0] + 128) * sensitivity) / 256; 137 st->magn_raw_to_gauss[1] = (((int32_t)asa[1] + 128) * sensitivity) / 256; 138 st->magn_raw_to_gauss[2] = (((int32_t)asa[2] + 128) * sensitivity) / 256; 139 140 return 0; 141 } 142 143 /** 144 * inv_mpu_magn_probe() - probe and setup magnetometer chip 145 * @st: driver internal state 146 * 147 * Returns 0 on success, a negative error code otherwise 148 * 149 * It is probing the chip and setting up all needed i2c transfers. 150 * Noop if there is no magnetometer in the chip. 151 */ 152 int inv_mpu_magn_probe(struct inv_mpu6050_state *st) 153 { 154 uint8_t val; 155 int ret; 156 157 /* quit if chip is not supported */ 158 if (!inv_magn_supported(st)) 159 return 0; 160 161 /* configure i2c master aux port */ 162 ret = inv_mpu_aux_init(st); 163 if (ret) 164 return ret; 165 166 /* check and init mag chip */ 167 ret = inv_magn_init(st); 168 if (ret) 169 return ret; 170 171 /* 172 * configure mpu i2c master accesses 173 * i2c SLV0: read sensor data, 7 bytes data(6)-ST2 174 * Byte swap data to store them in big-endian in impair address groups 175 */ 176 ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_ADDR(0), 177 INV_MPU6050_BIT_I2C_SLV_RNW | INV_MPU_MAGN_I2C_ADDR); 178 if (ret) 179 return ret; 180 181 ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_REG(0), 182 INV_MPU_MAGN_REG_DATA); 183 if (ret) 184 return ret; 185 186 ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 187 INV_MPU6050_BIT_SLV_EN | 188 INV_MPU6050_BIT_SLV_BYTE_SW | 189 INV_MPU6050_BIT_SLV_GRP | 190 INV_MPU9X50_BYTES_MAGN); 191 if (ret) 192 return ret; 193 194 /* i2c SLV1: launch single measurement */ 195 ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_ADDR(1), 196 INV_MPU_MAGN_I2C_ADDR); 197 if (ret) 198 return ret; 199 200 ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_REG(1), 201 INV_MPU_MAGN_REG_CNTL1); 202 if (ret) 203 return ret; 204 205 /* add 16 bits mode for MPU925x */ 206 val = INV_MPU_MAGN_BITS_MODE_SINGLE; 207 switch (st->chip_type) { 208 case INV_MPU9250: 209 case INV_MPU9255: 210 val |= INV_MPU9250_MAGN_BIT_OUTPUT_BIT; 211 break; 212 default: 213 break; 214 } 215 ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_DO(1), val); 216 if (ret) 217 return ret; 218 219 return regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(1), 220 INV_MPU6050_BIT_SLV_EN | 1); 221 } 222 223 /** 224 * inv_mpu_magn_set_rate() - set magnetometer sampling rate 225 * @st: driver internal state 226 * @fifo_rate: mpu set fifo rate 227 * 228 * Returns 0 on success, a negative error code otherwise 229 * 230 * Limit sampling frequency to the maximum value supported by the 231 * magnetometer chip. Resulting in duplicated data for higher frequencies. 232 * Noop if there is no magnetometer in the chip. 233 */ 234 int inv_mpu_magn_set_rate(const struct inv_mpu6050_state *st, int fifo_rate) 235 { 236 uint8_t d; 237 238 /* quit if chip is not supported */ 239 if (!inv_magn_supported(st)) 240 return 0; 241 242 /* 243 * update i2c master delay to limit mag sampling to max frequency 244 * compute fifo_rate divider d: rate = fifo_rate / (d + 1) 245 */ 246 if (fifo_rate > INV_MPU_MAGN_FREQ_HZ_MAX) 247 d = fifo_rate / INV_MPU_MAGN_FREQ_HZ_MAX - 1; 248 else 249 d = 0; 250 251 return regmap_write(st->map, INV_MPU6050_REG_I2C_SLV4_CTRL, d); 252 } 253 254 /** 255 * inv_mpu_magn_set_orient() - fill magnetometer mounting matrix 256 * @st: driver internal state 257 * 258 * Returns 0 on success, a negative error code otherwise 259 * 260 * Fill magnetometer mounting matrix using the provided chip matrix. 261 */ 262 int inv_mpu_magn_set_orient(struct inv_mpu6050_state *st) 263 { 264 const char *orient; 265 char *str; 266 int i; 267 268 /* fill magnetometer orientation */ 269 switch (st->chip_type) { 270 case INV_MPU9150: 271 case INV_MPU9250: 272 case INV_MPU9255: 273 /* x <- y */ 274 st->magn_orient.rotation[0] = st->orientation.rotation[3]; 275 st->magn_orient.rotation[1] = st->orientation.rotation[4]; 276 st->magn_orient.rotation[2] = st->orientation.rotation[5]; 277 /* y <- x */ 278 st->magn_orient.rotation[3] = st->orientation.rotation[0]; 279 st->magn_orient.rotation[4] = st->orientation.rotation[1]; 280 st->magn_orient.rotation[5] = st->orientation.rotation[2]; 281 /* z <- -z */ 282 for (i = 0; i < 3; ++i) { 283 orient = st->orientation.rotation[6 + i]; 284 /* use length + 2 for adding minus sign if needed */ 285 str = devm_kzalloc(regmap_get_device(st->map), 286 strlen(orient) + 2, GFP_KERNEL); 287 if (str == NULL) 288 return -ENOMEM; 289 if (strcmp(orient, "0") == 0) { 290 strcpy(str, orient); 291 } else if (orient[0] == '-') { 292 strcpy(str, &orient[1]); 293 } else { 294 str[0] = '-'; 295 strcpy(&str[1], orient); 296 } 297 st->magn_orient.rotation[6 + i] = str; 298 } 299 break; 300 default: 301 st->magn_orient = st->orientation; 302 break; 303 } 304 305 return 0; 306 } 307 308 /** 309 * inv_mpu_magn_read() - read magnetometer data 310 * @st: driver internal state 311 * @axis: IIO modifier axis value 312 * @val: store corresponding axis value 313 * 314 * Returns 0 on success, a negative error code otherwise 315 */ 316 int inv_mpu_magn_read(struct inv_mpu6050_state *st, int axis, int *val) 317 { 318 unsigned int status; 319 __be16 data; 320 uint8_t addr; 321 int ret; 322 323 /* quit if chip is not supported */ 324 if (!inv_magn_supported(st)) 325 return -ENODEV; 326 327 /* Mag data: XH,XL,YH,YL,ZH,ZL */ 328 switch (axis) { 329 case IIO_MOD_X: 330 addr = 0; 331 break; 332 case IIO_MOD_Y: 333 addr = 2; 334 break; 335 case IIO_MOD_Z: 336 addr = 4; 337 break; 338 default: 339 return -EINVAL; 340 } 341 addr += INV_MPU6050_REG_EXT_SENS_DATA; 342 343 /* check i2c status and read raw data */ 344 ret = regmap_read(st->map, INV_MPU6050_REG_I2C_MST_STATUS, &status); 345 if (ret) 346 return ret; 347 348 if (status & INV_MPU6050_BIT_I2C_SLV0_NACK || 349 status & INV_MPU6050_BIT_I2C_SLV1_NACK) 350 return -EIO; 351 352 ret = regmap_bulk_read(st->map, addr, &data, sizeof(data)); 353 if (ret) 354 return ret; 355 356 *val = (int16_t)be16_to_cpu(data); 357 358 return IIO_VAL_INT; 359 } 360