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 } 155 156 /* 157 * Fill the last trailing 0s which are unfilled with increments of 158 * 100 milli celsius till 1023 code 159 */ 160 i = TABLE_SIZE - 1; 161 while (!derived_table[i]) 162 i--; 163 164 i++; 165 inc = 1; 166 while (i < TABLE_SIZE) { 167 derived_table[i] = derived_table[i - 1] + inc * 100; 168 i++; 169 } 170 171 return 0; 172 } 173 174 struct k3_thermal_data; 175 176 struct k3_j72xx_bandgap { 177 struct device *dev; 178 void __iomem *base; 179 void __iomem *cfg2_base; 180 void __iomem *fuse_base; 181 struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS]; 182 }; 183 184 /* common data structures */ 185 struct k3_thermal_data { 186 struct k3_j72xx_bandgap *bgp; 187 u32 ctrl_offset; 188 u32 stat_offset; 189 }; 190 191 static int two_cmp(int tmp, int mask) 192 { 193 tmp = ~(tmp); 194 tmp &= mask; 195 tmp += 1; 196 197 /* Return negative value */ 198 return (0 - tmp); 199 } 200 201 static unsigned int vtm_get_best_value(unsigned int s0, unsigned int s1, 202 unsigned int s2) 203 { 204 int d01 = abs(s0 - s1); 205 int d02 = abs(s0 - s2); 206 int d12 = abs(s1 - s2); 207 208 if (d01 <= d02 && d01 <= d12) 209 return (s0 + s1) / 2; 210 211 if (d02 <= d01 && d02 <= d12) 212 return (s0 + s2) / 2; 213 214 return (s1 + s2) / 2; 215 } 216 217 static inline int k3_bgp_read_temp(struct k3_thermal_data *devdata, 218 int *temp) 219 { 220 struct k3_j72xx_bandgap *bgp; 221 unsigned int dtemp, s0, s1, s2; 222 223 bgp = devdata->bgp; 224 /* 225 * Errata is applicable for am654 pg 1.0 silicon/J7ES. There 226 * is a variation of the order for certain degree centigrade on AM654. 227 * Work around that by getting the average of two closest 228 * readings out of three readings everytime we want to 229 * report temperatures. 230 * 231 * Errata workaround. 232 */ 233 s0 = readl(bgp->base + devdata->stat_offset) & 234 K3_VTM_TS_STAT_DTEMP_MASK; 235 s1 = readl(bgp->base + devdata->stat_offset) & 236 K3_VTM_TS_STAT_DTEMP_MASK; 237 s2 = readl(bgp->base + devdata->stat_offset) & 238 K3_VTM_TS_STAT_DTEMP_MASK; 239 dtemp = vtm_get_best_value(s0, s1, s2); 240 241 if (dtemp < 0 || dtemp >= TABLE_SIZE) 242 return -EINVAL; 243 244 *temp = derived_table[dtemp]; 245 246 return 0; 247 } 248 249 /* Get temperature callback function for thermal zone */ 250 static int k3_thermal_get_temp(struct thermal_zone_device *tz, int *temp) 251 { 252 struct k3_thermal_data *data = tz->devdata; 253 int ret = 0; 254 255 ret = k3_bgp_read_temp(data, temp); 256 if (ret) 257 return ret; 258 259 return ret; 260 } 261 262 static const struct thermal_zone_device_ops k3_of_thermal_ops = { 263 .get_temp = k3_thermal_get_temp, 264 }; 265 266 static int k3_j72xx_bandgap_temp_to_adc_code(int temp) 267 { 268 int low = 0, high = TABLE_SIZE - 1, mid; 269 270 if (temp > 160000 || temp < -50000) 271 return -EINVAL; 272 273 /* Binary search to find the adc code */ 274 while (low < (high - 1)) { 275 mid = (low + high) / 2; 276 if (temp <= derived_table[mid]) 277 high = mid; 278 else 279 low = mid; 280 } 281 282 return mid; 283 } 284 285 static void get_efuse_values(int id, struct k3_thermal_data *data, int *err, 286 struct k3_j72xx_bandgap *bgp) 287 { 288 int i, tmp, pow; 289 int ct_offsets[5][K3_VTM_CORRECTION_TEMP_CNT] = { 290 { 0x0, 0x8, 0x4 }, 291 { 0x0, 0x8, 0x4 }, 292 { 0x0, -1, 0x4 }, 293 { 0x0, 0xC, -1 }, 294 { 0x0, 0xc, 0x8 } 295 }; 296 int ct_bm[5][K3_VTM_CORRECTION_TEMP_CNT] = { 297 { 0x3f, 0x1fe000, 0x1ff }, 298 { 0xfc0, 0x1fe000, 0x3fe00 }, 299 { 0x3f000, 0x7f800000, 0x7fc0000 }, 300 { 0xfc0000, 0x1fe0, 0x1f800000 }, 301 { 0x3f000000, 0x1fe000, 0x1ff0 } 302 }; 303 304 for (i = 0; i < 3; i++) { 305 /* Extract the offset value using bit-mask */ 306 if (ct_offsets[id][i] == -1 && i == 1) { 307 /* 25C offset Case of Sensor 2 split between 2 regs */ 308 tmp = (readl(bgp->fuse_base + 0x8) & 0xE0000000) >> (29); 309 tmp |= ((readl(bgp->fuse_base + 0xC) & 0x1F) << 3); 310 pow = tmp & 0x80; 311 } else if (ct_offsets[id][i] == -1 && i == 2) { 312 /* 125C Case of Sensor 3 split between 2 regs */ 313 tmp = (readl(bgp->fuse_base + 0x4) & 0xF8000000) >> (27); 314 tmp |= ((readl(bgp->fuse_base + 0x8) & 0xF) << 5); 315 pow = tmp & 0x100; 316 } else { 317 tmp = readl(bgp->fuse_base + ct_offsets[id][i]); 318 tmp &= ct_bm[id][i]; 319 tmp = tmp >> __ffs(ct_bm[id][i]); 320 321 /* Obtain the sign bit pow*/ 322 pow = ct_bm[id][i] >> __ffs(ct_bm[id][i]); 323 pow += 1; 324 pow /= 2; 325 } 326 327 /* Check for negative value */ 328 if (tmp & pow) { 329 /* 2's complement value */ 330 tmp = two_cmp(tmp, ct_bm[id][i] >> __ffs(ct_bm[id][i])); 331 } 332 err[i] = tmp; 333 } 334 335 /* Err value for 150C is set to 0 */ 336 err[i] = 0; 337 } 338 339 static void print_look_up_table(struct device *dev, int *ref_table) 340 { 341 int i; 342 343 dev_dbg(dev, "The contents of derived array\n"); 344 dev_dbg(dev, "Code Temperature\n"); 345 for (i = 0; i < TABLE_SIZE; i++) 346 dev_dbg(dev, "%d %d %d\n", i, derived_table[i], ref_table[i]); 347 } 348 349 struct k3_j72xx_bandgap_data { 350 unsigned int has_errata_i2128; 351 }; 352 353 static int k3_j72xx_bandgap_probe(struct platform_device *pdev) 354 { 355 int ret = 0, cnt, val, id; 356 int high_max, low_temp; 357 struct resource *res; 358 struct device *dev = &pdev->dev; 359 struct k3_j72xx_bandgap *bgp; 360 struct k3_thermal_data *data; 361 int workaround_needed = 0; 362 const struct k3_j72xx_bandgap_data *driver_data; 363 struct thermal_zone_device *ti_thermal; 364 int *ref_table; 365 struct err_values err_vals; 366 367 const s64 golden_factors[] = { 368 -490019999999999936, 369 3251200000000000, 370 -1705800000000, 371 603730000, 372 -92627, 373 }; 374 375 const s64 pvt_wa_factors[] = { 376 -415230000000000000, 377 3126600000000000, 378 -1157800000000, 379 }; 380 381 bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL); 382 if (!bgp) 383 return -ENOMEM; 384 385 bgp->dev = dev; 386 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 387 bgp->base = devm_ioremap_resource(dev, res); 388 if (IS_ERR(bgp->base)) 389 return PTR_ERR(bgp->base); 390 391 res = platform_get_resource(pdev, IORESOURCE_MEM, 1); 392 bgp->cfg2_base = devm_ioremap_resource(dev, res); 393 if (IS_ERR(bgp->cfg2_base)) 394 return PTR_ERR(bgp->cfg2_base); 395 396 res = platform_get_resource(pdev, IORESOURCE_MEM, 2); 397 bgp->fuse_base = devm_ioremap_resource(dev, res); 398 if (IS_ERR(bgp->fuse_base)) 399 return PTR_ERR(bgp->fuse_base); 400 401 driver_data = of_device_get_match_data(dev); 402 if (driver_data) 403 workaround_needed = driver_data->has_errata_i2128; 404 405 pm_runtime_enable(dev); 406 ret = pm_runtime_get_sync(dev); 407 if (ret < 0) { 408 pm_runtime_put_noidle(dev); 409 pm_runtime_disable(dev); 410 return ret; 411 } 412 413 /* Get the sensor count in the VTM */ 414 val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET); 415 cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK; 416 cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK); 417 418 data = devm_kcalloc(bgp->dev, cnt, sizeof(*data), GFP_KERNEL); 419 if (!data) { 420 ret = -ENOMEM; 421 goto err_alloc; 422 } 423 424 ref_table = kzalloc(sizeof(*ref_table) * TABLE_SIZE, GFP_KERNEL); 425 if (!ref_table) { 426 ret = -ENOMEM; 427 goto err_alloc; 428 } 429 430 derived_table = devm_kzalloc(bgp->dev, sizeof(*derived_table) * TABLE_SIZE, 431 GFP_KERNEL); 432 if (!derived_table) { 433 ret = -ENOMEM; 434 goto err_free_ref_table; 435 } 436 437 /* Workaround not needed if bit30/bit31 is set even for J721e */ 438 if (workaround_needed && (readl(bgp->fuse_base + 0x0) & 0xc0000000) == 0xc0000000) 439 workaround_needed = false; 440 441 dev_dbg(bgp->dev, "Work around %sneeded\n", 442 workaround_needed ? "not " : ""); 443 444 if (!workaround_needed) 445 init_table(5, ref_table, golden_factors); 446 else 447 init_table(3, ref_table, pvt_wa_factors); 448 449 /* Register the thermal sensors */ 450 for (id = 0; id < cnt; id++) { 451 data[id].bgp = bgp; 452 data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + id * 0x20; 453 data[id].stat_offset = data[id].ctrl_offset + 454 K3_VTM_TMPSENS_STAT_OFFSET; 455 456 if (workaround_needed) { 457 /* ref adc values for -40C, 30C & 125C respectively */ 458 err_vals.refs[0] = MINUS40CREF; 459 err_vals.refs[1] = PLUS30CREF; 460 err_vals.refs[2] = PLUS125CREF; 461 err_vals.refs[3] = PLUS150CREF; 462 get_efuse_values(id, &data[id], err_vals.errs, bgp); 463 } 464 465 if (id == 0 && workaround_needed) 466 prep_lookup_table(&err_vals, ref_table); 467 else if (id == 0 && !workaround_needed) 468 memcpy(derived_table, ref_table, TABLE_SIZE * 4); 469 470 val = readl(data[id].bgp->cfg2_base + data[id].ctrl_offset); 471 val |= (K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN | 472 K3_VTM_TMPSENS_CTRL_SOC | 473 K3_VTM_TMPSENS_CTRL_CLRZ | BIT(4)); 474 writel(val, data[id].bgp->cfg2_base + data[id].ctrl_offset); 475 476 bgp->ts_data[id] = &data[id]; 477 ti_thermal = devm_thermal_of_zone_register(bgp->dev, id, &data[id], 478 &k3_of_thermal_ops); 479 if (IS_ERR(ti_thermal)) { 480 dev_err(bgp->dev, "thermal zone device is NULL\n"); 481 ret = PTR_ERR(ti_thermal); 482 goto err_free_ref_table; 483 } 484 } 485 486 /* 487 * Program TSHUT thresholds 488 * Step 1: set the thresholds to ~123C and 105C WKUP_VTM_MISC_CTRL2 489 * Step 2: WKUP_VTM_TMPSENS_CTRL_j set the MAXT_OUTRG_EN bit 490 * This is already taken care as per of init 491 * Step 3: WKUP_VTM_MISC_CTRL set the ANYMAXT_OUTRG_ALERT_EN bit 492 */ 493 high_max = k3_j72xx_bandgap_temp_to_adc_code(MAX_TEMP); 494 low_temp = k3_j72xx_bandgap_temp_to_adc_code(COOL_DOWN_TEMP); 495 496 writel((low_temp << 16) | high_max, data[0].bgp->cfg2_base + 497 K3_VTM_MISC_CTRL2_OFFSET); 498 mdelay(100); 499 writel(K3_VTM_ANYMAXT_OUTRG_ALERT_EN, data[0].bgp->cfg2_base + 500 K3_VTM_MISC_CTRL_OFFSET); 501 502 platform_set_drvdata(pdev, bgp); 503 504 print_look_up_table(dev, ref_table); 505 /* 506 * Now that the derived_table has the appropriate look up values 507 * Free up the ref_table 508 */ 509 kfree(ref_table); 510 511 return 0; 512 513 err_free_ref_table: 514 kfree(ref_table); 515 516 err_alloc: 517 pm_runtime_put_sync(&pdev->dev); 518 pm_runtime_disable(&pdev->dev); 519 520 return ret; 521 } 522 523 static int k3_j72xx_bandgap_remove(struct platform_device *pdev) 524 { 525 pm_runtime_put_sync(&pdev->dev); 526 pm_runtime_disable(&pdev->dev); 527 528 return 0; 529 } 530 531 static const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j721e_data = { 532 .has_errata_i2128 = 1, 533 }; 534 535 static const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j7200_data = { 536 .has_errata_i2128 = 0, 537 }; 538 539 static const struct of_device_id of_k3_j72xx_bandgap_match[] = { 540 { 541 .compatible = "ti,j721e-vtm", 542 .data = &k3_j72xx_bandgap_j721e_data, 543 }, 544 { 545 .compatible = "ti,j7200-vtm", 546 .data = &k3_j72xx_bandgap_j7200_data, 547 }, 548 { /* sentinel */ }, 549 }; 550 MODULE_DEVICE_TABLE(of, of_k3_j72xx_bandgap_match); 551 552 static struct platform_driver k3_j72xx_bandgap_sensor_driver = { 553 .probe = k3_j72xx_bandgap_probe, 554 .remove = k3_j72xx_bandgap_remove, 555 .driver = { 556 .name = "k3-j72xx-soc-thermal", 557 .of_match_table = of_k3_j72xx_bandgap_match, 558 }, 559 }; 560 561 module_platform_driver(k3_j72xx_bandgap_sensor_driver); 562 563 MODULE_DESCRIPTION("K3 bandgap temperature sensor driver"); 564 MODULE_LICENSE("GPL"); 565 MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>"); 566