1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * TI Bandgap temperature sensor driver for J72XX SoC Family 4 * 5 * Copyright (C) 2021 Texas Instruments Incorporated - http://www.ti.com/ 6 */ 7 8 #include <linux/math.h> 9 #include <linux/math64.h> 10 #include <linux/module.h> 11 #include <linux/init.h> 12 #include <linux/kernel.h> 13 #include <linux/pm_runtime.h> 14 #include <linux/err.h> 15 #include <linux/types.h> 16 #include <linux/of_platform.h> 17 #include <linux/io.h> 18 #include <linux/thermal.h> 19 #include <linux/of.h> 20 #include <linux/delay.h> 21 #include <linux/slab.h> 22 23 #define K3_VTM_DEVINFO_PWR0_OFFSET 0x4 24 #define K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK 0xf0 25 #define K3_VTM_TMPSENS0_CTRL_OFFSET 0x300 26 #define K3_VTM_MISC_CTRL_OFFSET 0xc 27 #define K3_VTM_TMPSENS_STAT_OFFSET 0x8 28 #define K3_VTM_ANYMAXT_OUTRG_ALERT_EN 0x1 29 #define K3_VTM_MISC_CTRL2_OFFSET 0x10 30 #define K3_VTM_TS_STAT_DTEMP_MASK 0x3ff 31 #define K3_VTM_MAX_NUM_TS 8 32 #define K3_VTM_TMPSENS_CTRL_SOC BIT(5) 33 #define K3_VTM_TMPSENS_CTRL_CLRZ BIT(6) 34 #define K3_VTM_TMPSENS_CTRL_CLKON_REQ BIT(7) 35 #define K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN BIT(11) 36 37 #define K3_VTM_CORRECTION_TEMP_CNT 3 38 39 #define MINUS40CREF 5 40 #define PLUS30CREF 253 41 #define PLUS125CREF 730 42 #define PLUS150CREF 940 43 44 #define TABLE_SIZE 1024 45 #define MAX_TEMP 123000 46 #define COOL_DOWN_TEMP 105000 47 48 #define FACTORS_REDUCTION 13 49 static int *derived_table; 50 51 static int compute_value(int index, const s64 *factors, int nr_factors, 52 int reduction) 53 { 54 s64 value = 0; 55 int i; 56 57 for (i = 0; i < nr_factors; i++) 58 value += factors[i] * int_pow(index, i); 59 60 return (int)div64_s64(value, int_pow(10, reduction)); 61 } 62 63 static void init_table(int factors_size, int *table, const s64 *factors) 64 { 65 int i; 66 67 for (i = 0; i < TABLE_SIZE; i++) 68 table[i] = compute_value(i, factors, factors_size, 69 FACTORS_REDUCTION); 70 } 71 72 /** 73 * struct err_values - structure containing error/reference values 74 * @refs: reference error values for -40C, 30C, 125C & 150C 75 * @errs: Actual error values for -40C, 30C, 125C & 150C read from the efuse 76 */ 77 struct err_values { 78 int refs[4]; 79 int errs[4]; 80 }; 81 82 static void create_table_segments(struct err_values *err_vals, int seg, 83 int *ref_table) 84 { 85 int m = 0, c, num, den, i, err, idx1, idx2, err1, err2, ref1, ref2; 86 87 if (seg == 0) 88 idx1 = 0; 89 else 90 idx1 = err_vals->refs[seg]; 91 92 idx2 = err_vals->refs[seg + 1]; 93 err1 = err_vals->errs[seg]; 94 err2 = err_vals->errs[seg + 1]; 95 ref1 = err_vals->refs[seg]; 96 ref2 = err_vals->refs[seg + 1]; 97 98 /* 99 * Calculate the slope with adc values read from the register 100 * as the y-axis param and err in adc value as x-axis param 101 */ 102 num = ref2 - ref1; 103 den = err2 - err1; 104 if (den) 105 m = num / den; 106 c = ref2 - m * err2; 107 108 /* 109 * Take care of divide by zero error if error values are same 110 * Or when the slope is 0 111 */ 112 if (den != 0 && m != 0) { 113 for (i = idx1; i <= idx2; i++) { 114 err = (i - c) / m; 115 if (((i + err) < 0) || ((i + err) >= TABLE_SIZE)) 116 continue; 117 derived_table[i] = ref_table[i + err]; 118 } 119 } else { /* Constant error take care of divide by zero */ 120 for (i = idx1; i <= idx2; i++) { 121 if (((i + err1) < 0) || ((i + err1) >= TABLE_SIZE)) 122 continue; 123 derived_table[i] = ref_table[i + err1]; 124 } 125 } 126 } 127 128 static int prep_lookup_table(struct err_values *err_vals, int *ref_table) 129 { 130 int inc, i, seg; 131 132 /* 133 * Fill up the lookup table under 3 segments 134 * region -40C to +30C 135 * region +30C to +125C 136 * region +125C to +150C 137 */ 138 for (seg = 0; seg < 3; seg++) 139 create_table_segments(err_vals, seg, ref_table); 140 141 /* Get to the first valid temperature */ 142 i = 0; 143 while (!derived_table[i]) 144 i++; 145 146 /* 147 * Get to the last zero index and back fill the temperature for 148 * sake of continuity 149 */ 150 if (i) { 151 /* 300 milli celsius steps */ 152 while (i--) 153 derived_table[i] = derived_table[i + 1] - 300; 154 /* case 0 */ 155 derived_table[i] = derived_table[i + 1] - 300; 156 } 157 158 /* 159 * Fill the last trailing 0s which are unfilled with increments of 160 * 100 milli celsius till 1023 code 161 */ 162 i = TABLE_SIZE - 1; 163 while (!derived_table[i]) 164 i--; 165 166 i++; 167 inc = 1; 168 while (i < TABLE_SIZE) { 169 derived_table[i] = derived_table[i - 1] + inc * 100; 170 i++; 171 } 172 173 return 0; 174 } 175 176 struct k3_thermal_data; 177 178 struct k3_j72xx_bandgap { 179 struct device *dev; 180 void __iomem *base; 181 void __iomem *cfg2_base; 182 void __iomem *fuse_base; 183 struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS]; 184 }; 185 186 /* common data structures */ 187 struct k3_thermal_data { 188 struct k3_j72xx_bandgap *bgp; 189 u32 ctrl_offset; 190 u32 stat_offset; 191 }; 192 193 static int two_cmp(int tmp, int mask) 194 { 195 tmp = ~(tmp); 196 tmp &= mask; 197 tmp += 1; 198 199 /* Return negative value */ 200 return (0 - tmp); 201 } 202 203 static unsigned int vtm_get_best_value(unsigned int s0, unsigned int s1, 204 unsigned int s2) 205 { 206 int d01 = abs(s0 - s1); 207 int d02 = abs(s0 - s2); 208 int d12 = abs(s1 - s2); 209 210 if (d01 <= d02 && d01 <= d12) 211 return (s0 + s1) / 2; 212 213 if (d02 <= d01 && d02 <= d12) 214 return (s0 + s2) / 2; 215 216 return (s1 + s2) / 2; 217 } 218 219 static inline int k3_bgp_read_temp(struct k3_thermal_data *devdata, 220 int *temp) 221 { 222 struct k3_j72xx_bandgap *bgp; 223 unsigned int dtemp, s0, s1, s2; 224 225 bgp = devdata->bgp; 226 /* 227 * Errata is applicable for am654 pg 1.0 silicon/J7ES. There 228 * is a variation of the order for certain degree centigrade on AM654. 229 * Work around that by getting the average of two closest 230 * readings out of three readings everytime we want to 231 * report temperatures. 232 * 233 * Errata workaround. 234 */ 235 s0 = readl(bgp->base + devdata->stat_offset) & 236 K3_VTM_TS_STAT_DTEMP_MASK; 237 s1 = readl(bgp->base + devdata->stat_offset) & 238 K3_VTM_TS_STAT_DTEMP_MASK; 239 s2 = readl(bgp->base + devdata->stat_offset) & 240 K3_VTM_TS_STAT_DTEMP_MASK; 241 dtemp = vtm_get_best_value(s0, s1, s2); 242 243 if (dtemp < 0 || dtemp >= TABLE_SIZE) 244 return -EINVAL; 245 246 *temp = derived_table[dtemp]; 247 248 return 0; 249 } 250 251 /* Get temperature callback function for thermal zone */ 252 static int k3_thermal_get_temp(void *devdata, int *temp) 253 { 254 struct k3_thermal_data *data = devdata; 255 int ret = 0; 256 257 ret = k3_bgp_read_temp(data, temp); 258 if (ret) 259 return ret; 260 261 return ret; 262 } 263 264 static const struct thermal_zone_of_device_ops k3_of_thermal_ops = { 265 .get_temp = k3_thermal_get_temp, 266 }; 267 268 static int k3_j72xx_bandgap_temp_to_adc_code(int temp) 269 { 270 int low = 0, high = TABLE_SIZE - 1, mid; 271 272 if (temp > 160000 || temp < -50000) 273 return -EINVAL; 274 275 /* Binary search to find the adc code */ 276 while (low < (high - 1)) { 277 mid = (low + high) / 2; 278 if (temp <= derived_table[mid]) 279 high = mid; 280 else 281 low = mid; 282 } 283 284 return mid; 285 } 286 287 static void get_efuse_values(int id, struct k3_thermal_data *data, int *err, 288 struct k3_j72xx_bandgap *bgp) 289 { 290 int i, tmp, pow; 291 int ct_offsets[5][K3_VTM_CORRECTION_TEMP_CNT] = { 292 { 0x0, 0x8, 0x4 }, 293 { 0x0, 0x8, 0x4 }, 294 { 0x0, -1, 0x4 }, 295 { 0x0, 0xC, -1 }, 296 { 0x0, 0xc, 0x8 } 297 }; 298 int ct_bm[5][K3_VTM_CORRECTION_TEMP_CNT] = { 299 { 0x3f, 0x1fe000, 0x1ff }, 300 { 0xfc0, 0x1fe000, 0x3fe00 }, 301 { 0x3f000, 0x7f800000, 0x7fc0000 }, 302 { 0xfc0000, 0x1fe0, 0x1f800000 }, 303 { 0x3f000000, 0x1fe000, 0x1ff0 } 304 }; 305 306 for (i = 0; i < 3; i++) { 307 /* Extract the offset value using bit-mask */ 308 if (ct_offsets[id][i] == -1 && i == 1) { 309 /* 25C offset Case of Sensor 2 split between 2 regs */ 310 tmp = (readl(bgp->fuse_base + 0x8) & 0xE0000000) >> (29); 311 tmp |= ((readl(bgp->fuse_base + 0xC) & 0x1F) << 3); 312 pow = tmp & 0x80; 313 } else if (ct_offsets[id][i] == -1 && i == 2) { 314 /* 125C Case of Sensor 3 split between 2 regs */ 315 tmp = (readl(bgp->fuse_base + 0x4) & 0xF8000000) >> (27); 316 tmp |= ((readl(bgp->fuse_base + 0x8) & 0xF) << 5); 317 pow = tmp & 0x100; 318 } else { 319 tmp = readl(bgp->fuse_base + ct_offsets[id][i]); 320 tmp &= ct_bm[id][i]; 321 tmp = tmp >> __ffs(ct_bm[id][i]); 322 323 /* Obtain the sign bit pow*/ 324 pow = ct_bm[id][i] >> __ffs(ct_bm[id][i]); 325 pow += 1; 326 pow /= 2; 327 } 328 329 /* Check for negative value */ 330 if (tmp & pow) { 331 /* 2's complement value */ 332 tmp = two_cmp(tmp, ct_bm[id][i] >> __ffs(ct_bm[id][i])); 333 } 334 err[i] = tmp; 335 } 336 337 /* Err value for 150C is set to 0 */ 338 err[i] = 0; 339 } 340 341 static void print_look_up_table(struct device *dev, int *ref_table) 342 { 343 int i; 344 345 dev_dbg(dev, "The contents of derived array\n"); 346 dev_dbg(dev, "Code Temperature\n"); 347 for (i = 0; i < TABLE_SIZE; i++) 348 dev_dbg(dev, "%d %d %d\n", i, derived_table[i], ref_table[i]); 349 } 350 351 struct k3_j72xx_bandgap_data { 352 unsigned int has_errata_i2128; 353 }; 354 355 static int k3_j72xx_bandgap_probe(struct platform_device *pdev) 356 { 357 int ret = 0, cnt, val, id; 358 int high_max, low_temp; 359 struct resource *res; 360 struct device *dev = &pdev->dev; 361 struct k3_j72xx_bandgap *bgp; 362 struct k3_thermal_data *data; 363 int workaround_needed = 0; 364 const struct k3_j72xx_bandgap_data *driver_data; 365 struct thermal_zone_device *ti_thermal; 366 int *ref_table; 367 struct err_values err_vals; 368 369 const s64 golden_factors[] = { 370 -490019999999999936, 371 3251200000000000, 372 -1705800000000, 373 603730000, 374 -92627, 375 }; 376 377 const s64 pvt_wa_factors[] = { 378 -415230000000000000, 379 3126600000000000, 380 -1157800000000, 381 }; 382 383 bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL); 384 if (!bgp) 385 return -ENOMEM; 386 387 bgp->dev = dev; 388 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 389 bgp->base = devm_ioremap_resource(dev, res); 390 if (IS_ERR(bgp->base)) 391 return PTR_ERR(bgp->base); 392 393 res = platform_get_resource(pdev, IORESOURCE_MEM, 1); 394 bgp->cfg2_base = devm_ioremap_resource(dev, res); 395 if (IS_ERR(bgp->cfg2_base)) 396 return PTR_ERR(bgp->cfg2_base); 397 398 res = platform_get_resource(pdev, IORESOURCE_MEM, 2); 399 bgp->fuse_base = devm_ioremap_resource(dev, res); 400 if (IS_ERR(bgp->fuse_base)) 401 return PTR_ERR(bgp->fuse_base); 402 403 driver_data = of_device_get_match_data(dev); 404 if (driver_data) 405 workaround_needed = driver_data->has_errata_i2128; 406 407 pm_runtime_enable(dev); 408 ret = pm_runtime_get_sync(dev); 409 if (ret < 0) { 410 pm_runtime_put_noidle(dev); 411 pm_runtime_disable(dev); 412 return ret; 413 } 414 415 /* Get the sensor count in the VTM */ 416 val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET); 417 cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK; 418 cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK); 419 420 data = devm_kcalloc(bgp->dev, cnt, sizeof(*data), GFP_KERNEL); 421 if (!data) { 422 ret = -ENOMEM; 423 goto err_alloc; 424 } 425 426 ref_table = kzalloc(sizeof(*ref_table) * TABLE_SIZE, GFP_KERNEL); 427 if (!ref_table) { 428 ret = -ENOMEM; 429 goto err_alloc; 430 } 431 432 derived_table = devm_kzalloc(bgp->dev, sizeof(*derived_table) * TABLE_SIZE, 433 GFP_KERNEL); 434 if (!derived_table) { 435 ret = -ENOMEM; 436 goto err_alloc; 437 } 438 439 /* Workaround not needed if bit30/bit31 is set even for J721e */ 440 if (workaround_needed && (readl(bgp->fuse_base + 0x0) & 0xc0000000) == 0xc0000000) 441 workaround_needed = false; 442 443 dev_dbg(bgp->dev, "Work around %sneeded\n", 444 workaround_needed ? "not " : ""); 445 446 if (!workaround_needed) 447 init_table(5, ref_table, golden_factors); 448 else 449 init_table(3, ref_table, pvt_wa_factors); 450 451 /* Register the thermal sensors */ 452 for (id = 0; id < cnt; id++) { 453 data[id].bgp = bgp; 454 data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + id * 0x20; 455 data[id].stat_offset = data[id].ctrl_offset + 456 K3_VTM_TMPSENS_STAT_OFFSET; 457 458 if (workaround_needed) { 459 /* ref adc values for -40C, 30C & 125C respectively */ 460 err_vals.refs[0] = MINUS40CREF; 461 err_vals.refs[1] = PLUS30CREF; 462 err_vals.refs[2] = PLUS125CREF; 463 err_vals.refs[3] = PLUS150CREF; 464 get_efuse_values(id, &data[id], err_vals.errs, bgp); 465 } 466 467 if (id == 0 && workaround_needed) 468 prep_lookup_table(&err_vals, ref_table); 469 else if (id == 0 && !workaround_needed) 470 memcpy(derived_table, ref_table, TABLE_SIZE * 4); 471 472 val = readl(data[id].bgp->cfg2_base + data[id].ctrl_offset); 473 val |= (K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN | 474 K3_VTM_TMPSENS_CTRL_SOC | 475 K3_VTM_TMPSENS_CTRL_CLRZ | BIT(4)); 476 writel(val, data[id].bgp->cfg2_base + data[id].ctrl_offset); 477 478 bgp->ts_data[id] = &data[id]; 479 ti_thermal = 480 devm_thermal_zone_of_sensor_register(bgp->dev, id, 481 &data[id], 482 &k3_of_thermal_ops); 483 if (IS_ERR(ti_thermal)) { 484 dev_err(bgp->dev, "thermal zone device is NULL\n"); 485 ret = PTR_ERR(ti_thermal); 486 goto err_alloc; 487 } 488 } 489 490 /* 491 * Program TSHUT thresholds 492 * Step 1: set the thresholds to ~123C and 105C WKUP_VTM_MISC_CTRL2 493 * Step 2: WKUP_VTM_TMPSENS_CTRL_j set the MAXT_OUTRG_EN bit 494 * This is already taken care as per of init 495 * Step 3: WKUP_VTM_MISC_CTRL set the ANYMAXT_OUTRG_ALERT_EN bit 496 */ 497 high_max = k3_j72xx_bandgap_temp_to_adc_code(MAX_TEMP); 498 low_temp = k3_j72xx_bandgap_temp_to_adc_code(COOL_DOWN_TEMP); 499 500 writel((low_temp << 16) | high_max, data[0].bgp->cfg2_base + 501 K3_VTM_MISC_CTRL2_OFFSET); 502 mdelay(100); 503 writel(K3_VTM_ANYMAXT_OUTRG_ALERT_EN, data[0].bgp->cfg2_base + 504 K3_VTM_MISC_CTRL_OFFSET); 505 506 platform_set_drvdata(pdev, bgp); 507 508 print_look_up_table(dev, ref_table); 509 /* 510 * Now that the derived_table has the appropriate look up values 511 * Free up the ref_table 512 */ 513 kfree(ref_table); 514 515 return 0; 516 517 err_alloc: 518 pm_runtime_put_sync(&pdev->dev); 519 pm_runtime_disable(&pdev->dev); 520 521 return ret; 522 } 523 524 static int k3_j72xx_bandgap_remove(struct platform_device *pdev) 525 { 526 pm_runtime_put_sync(&pdev->dev); 527 pm_runtime_disable(&pdev->dev); 528 529 return 0; 530 } 531 532 const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j721e_data = { 533 .has_errata_i2128 = 1, 534 }; 535 536 const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j7200_data = { 537 .has_errata_i2128 = 0, 538 }; 539 540 static const struct of_device_id of_k3_j72xx_bandgap_match[] = { 541 { 542 .compatible = "ti,j721e-vtm", 543 .data = &k3_j72xx_bandgap_j721e_data, 544 }, 545 { 546 .compatible = "ti,j7200-vtm", 547 .data = &k3_j72xx_bandgap_j7200_data, 548 }, 549 { /* sentinel */ }, 550 }; 551 MODULE_DEVICE_TABLE(of, of_k3_j72xx_bandgap_match); 552 553 static struct platform_driver k3_j72xx_bandgap_sensor_driver = { 554 .probe = k3_j72xx_bandgap_probe, 555 .remove = k3_j72xx_bandgap_remove, 556 .driver = { 557 .name = "k3-j72xx-soc-thermal", 558 .of_match_table = of_k3_j72xx_bandgap_match, 559 }, 560 }; 561 562 module_platform_driver(k3_j72xx_bandgap_sensor_driver); 563 564 MODULE_DESCRIPTION("K3 bandgap temperature sensor driver"); 565 MODULE_LICENSE("GPL"); 566 MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>"); 567