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/platform_device.h> 14#include <linux/pm_runtime.h> 15#include <linux/err.h> 16#include <linux/types.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 49static int *derived_table; 50 51static 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 63static 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 */ 77struct err_values { 78 int refs[4]; 79 int errs[4]; 80}; 81 82static 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 128static 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 174struct k3_thermal_data; 175 176struct k3_j72xx_bandgap { 177 struct device *dev; 178 void __iomem *base; 179 void __iomem *cfg2_base; 180 struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS]; 181}; 182 183/* common data structures */ 184struct k3_thermal_data { 185 struct k3_j72xx_bandgap *bgp; 186 u32 ctrl_offset; 187 u32 stat_offset; 188}; 189 190static int two_cmp(int tmp, int mask) 191{ 192 tmp = ~(tmp); 193 tmp &= mask; 194 tmp += 1; 195 196 /* Return negative value */ 197 return (0 - tmp); 198} 199 200static unsigned int vtm_get_best_value(unsigned int s0, unsigned int s1, 201 unsigned int s2) 202{ 203 int d01 = abs(s0 - s1); 204 int d02 = abs(s0 - s2); 205 int d12 = abs(s1 - s2); 206 207 if (d01 <= d02 && d01 <= d12) 208 return (s0 + s1) / 2; 209 210 if (d02 <= d01 && d02 <= d12) 211 return (s0 + s2) / 2; 212 213 return (s1 + s2) / 2; 214} 215 216static inline int k3_bgp_read_temp(struct k3_thermal_data *devdata, 217 int *temp) 218{ 219 struct k3_j72xx_bandgap *bgp; 220 unsigned int dtemp, s0, s1, s2; 221 222 bgp = devdata->bgp; 223 /* 224 * Errata is applicable for am654 pg 1.0 silicon/J7ES. There 225 * is a variation of the order for certain degree centigrade on AM654. 226 * Work around that by getting the average of two closest 227 * readings out of three readings everytime we want to 228 * report temperatures. 229 * 230 * Errata workaround. 231 */ 232 s0 = readl(bgp->base + devdata->stat_offset) & 233 K3_VTM_TS_STAT_DTEMP_MASK; 234 s1 = readl(bgp->base + devdata->stat_offset) & 235 K3_VTM_TS_STAT_DTEMP_MASK; 236 s2 = readl(bgp->base + devdata->stat_offset) & 237 K3_VTM_TS_STAT_DTEMP_MASK; 238 dtemp = vtm_get_best_value(s0, s1, s2); 239 240 if (dtemp < 0 || dtemp >= TABLE_SIZE) 241 return -EINVAL; 242 243 *temp = derived_table[dtemp]; 244 245 return 0; 246} 247 248/* Get temperature callback function for thermal zone */ 249static int k3_thermal_get_temp(struct thermal_zone_device *tz, int *temp) 250{ 251 return k3_bgp_read_temp(thermal_zone_device_priv(tz), temp); 252} 253 254static const struct thermal_zone_device_ops k3_of_thermal_ops = { 255 .get_temp = k3_thermal_get_temp, 256}; 257 258static int k3_j72xx_bandgap_temp_to_adc_code(int temp) 259{ 260 int low = 0, high = TABLE_SIZE - 1, mid; 261 262 if (temp > 160000 || temp < -50000) 263 return -EINVAL; 264 265 /* Binary search to find the adc code */ 266 while (low < (high - 1)) { 267 mid = (low + high) / 2; 268 if (temp <= derived_table[mid]) 269 high = mid; 270 else 271 low = mid; 272 } 273 274 return mid; 275} 276 277static void get_efuse_values(int id, struct k3_thermal_data *data, int *err, 278 void __iomem *fuse_base) 279{ 280 int i, tmp, pow; 281 int ct_offsets[5][K3_VTM_CORRECTION_TEMP_CNT] = { 282 { 0x0, 0x8, 0x4 }, 283 { 0x0, 0x8, 0x4 }, 284 { 0x0, -1, 0x4 }, 285 { 0x0, 0xC, -1 }, 286 { 0x0, 0xc, 0x8 } 287 }; 288 int ct_bm[5][K3_VTM_CORRECTION_TEMP_CNT] = { 289 { 0x3f, 0x1fe000, 0x1ff }, 290 { 0xfc0, 0x1fe000, 0x3fe00 }, 291 { 0x3f000, 0x7f800000, 0x7fc0000 }, 292 { 0xfc0000, 0x1fe0, 0x1f800000 }, 293 { 0x3f000000, 0x1fe000, 0x1ff0 } 294 }; 295 296 for (i = 0; i < 3; i++) { 297 /* Extract the offset value using bit-mask */ 298 if (ct_offsets[id][i] == -1 && i == 1) { 299 /* 25C offset Case of Sensor 2 split between 2 regs */ 300 tmp = (readl(fuse_base + 0x8) & 0xE0000000) >> (29); 301 tmp |= ((readl(fuse_base + 0xC) & 0x1F) << 3); 302 pow = tmp & 0x80; 303 } else if (ct_offsets[id][i] == -1 && i == 2) { 304 /* 125C Case of Sensor 3 split between 2 regs */ 305 tmp = (readl(fuse_base + 0x4) & 0xF8000000) >> (27); 306 tmp |= ((readl(fuse_base + 0x8) & 0xF) << 5); 307 pow = tmp & 0x100; 308 } else { 309 tmp = readl(fuse_base + ct_offsets[id][i]); 310 tmp &= ct_bm[id][i]; 311 tmp = tmp >> __ffs(ct_bm[id][i]); 312 313 /* Obtain the sign bit pow*/ 314 pow = ct_bm[id][i] >> __ffs(ct_bm[id][i]); 315 pow += 1; 316 pow /= 2; 317 } 318 319 /* Check for negative value */ 320 if (tmp & pow) { 321 /* 2's complement value */ 322 tmp = two_cmp(tmp, ct_bm[id][i] >> __ffs(ct_bm[id][i])); 323 } 324 err[i] = tmp; 325 } 326 327 /* Err value for 150C is set to 0 */ 328 err[i] = 0; 329} 330 331static void print_look_up_table(struct device *dev, int *ref_table) 332{ 333 int i; 334 335 dev_dbg(dev, "The contents of derived array\n"); 336 dev_dbg(dev, "Code Temperature\n"); 337 for (i = 0; i < TABLE_SIZE; i++) 338 dev_dbg(dev, "%d %d %d\n", i, derived_table[i], ref_table[i]); 339} 340 341struct k3_j72xx_bandgap_data { 342 const bool has_errata_i2128; 343}; 344 345static int k3_j72xx_bandgap_probe(struct platform_device *pdev) 346{ 347 int ret = 0, cnt, val, id; 348 int high_max, low_temp; 349 struct resource *res; 350 struct device *dev = &pdev->dev; 351 struct k3_j72xx_bandgap *bgp; 352 struct k3_thermal_data *data; 353 bool workaround_needed = false; 354 const struct k3_j72xx_bandgap_data *driver_data; 355 struct thermal_zone_device *ti_thermal; 356 int *ref_table; 357 struct err_values err_vals; 358 void __iomem *fuse_base; 359 360 const s64 golden_factors[] = { 361 -490019999999999936, 362 3251200000000000, 363 -1705800000000, 364 603730000, 365 -92627, 366 }; 367 368 const s64 pvt_wa_factors[] = { 369 -415230000000000000, 370 3126600000000000, 371 -1157800000000, 372 }; 373 374 bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL); 375 if (!bgp) 376 return -ENOMEM; 377 378 bgp->dev = dev; 379 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 380 bgp->base = devm_ioremap_resource(dev, res); 381 if (IS_ERR(bgp->base)) 382 return PTR_ERR(bgp->base); 383 384 res = platform_get_resource(pdev, IORESOURCE_MEM, 1); 385 bgp->cfg2_base = devm_ioremap_resource(dev, res); 386 if (IS_ERR(bgp->cfg2_base)) 387 return PTR_ERR(bgp->cfg2_base); 388 389 driver_data = of_device_get_match_data(dev); 390 if (driver_data) 391 workaround_needed = driver_data->has_errata_i2128; 392 393 /* 394 * Some of TI's J721E SoCs require a software trimming procedure 395 * for the temperature monitors to function properly. To determine 396 * if this particular SoC is NOT affected, both bits in the 397 * WKUP_SPARE_FUSE0[31:30] will be set (0xC0000000) indicating 398 * when software trimming should NOT be applied. 399 * 400 * https://www.ti.com/lit/er/sprz455c/sprz455c.pdf 401 */ 402 if (workaround_needed) { 403 res = platform_get_resource(pdev, IORESOURCE_MEM, 2); 404 fuse_base = devm_ioremap_resource(dev, res); 405 if (IS_ERR(fuse_base)) 406 return PTR_ERR(fuse_base); 407 408 if ((readl(fuse_base) & 0xc0000000) == 0xc0000000) 409 workaround_needed = false; 410 } 411 412 dev_dbg(bgp->dev, "Work around %sneeded\n", 413 workaround_needed ? "" : "not "); 414 415 pm_runtime_enable(dev); 416 ret = pm_runtime_get_sync(dev); 417 if (ret < 0) { 418 pm_runtime_put_noidle(dev); 419 pm_runtime_disable(dev); 420 return ret; 421 } 422 423 /* Get the sensor count in the VTM */ 424 val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET); 425 cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK; 426 cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK); 427 428 data = devm_kcalloc(bgp->dev, cnt, sizeof(*data), GFP_KERNEL); 429 if (!data) { 430 ret = -ENOMEM; 431 goto err_alloc; 432 } 433 434 ref_table = kzalloc(sizeof(*ref_table) * TABLE_SIZE, GFP_KERNEL); 435 if (!ref_table) { 436 ret = -ENOMEM; 437 goto err_alloc; 438 } 439 440 derived_table = devm_kzalloc(bgp->dev, sizeof(*derived_table) * TABLE_SIZE, 441 GFP_KERNEL); 442 if (!derived_table) { 443 ret = -ENOMEM; 444 goto err_free_ref_table; 445 } 446 447 if (!workaround_needed) 448 init_table(5, ref_table, golden_factors); 449 else 450 init_table(3, ref_table, pvt_wa_factors); 451 452 /* Register the thermal sensors */ 453 for (id = 0; id < cnt; id++) { 454 data[id].bgp = bgp; 455 data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + id * 0x20; 456 data[id].stat_offset = data[id].ctrl_offset + 457 K3_VTM_TMPSENS_STAT_OFFSET; 458 459 if (workaround_needed) { 460 /* ref adc values for -40C, 30C & 125C respectively */ 461 err_vals.refs[0] = MINUS40CREF; 462 err_vals.refs[1] = PLUS30CREF; 463 err_vals.refs[2] = PLUS125CREF; 464 err_vals.refs[3] = PLUS150CREF; 465 get_efuse_values(id, &data[id], err_vals.errs, fuse_base); 466 } 467 468 if (id == 0 && workaround_needed) 469 prep_lookup_table(&err_vals, ref_table); 470 else if (id == 0 && !workaround_needed) 471 memcpy(derived_table, ref_table, TABLE_SIZE * 4); 472 473 val = readl(data[id].bgp->cfg2_base + data[id].ctrl_offset); 474 val |= (K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN | 475 K3_VTM_TMPSENS_CTRL_SOC | 476 K3_VTM_TMPSENS_CTRL_CLRZ | BIT(4)); 477 writel(val, data[id].bgp->cfg2_base + data[id].ctrl_offset); 478 479 bgp->ts_data[id] = &data[id]; 480 ti_thermal = devm_thermal_of_zone_register(bgp->dev, id, &data[id], 481 &k3_of_thermal_ops); 482 if (IS_ERR(ti_thermal)) { 483 dev_err(bgp->dev, "thermal zone device is NULL\n"); 484 ret = PTR_ERR(ti_thermal); 485 goto err_free_ref_table; 486 } 487 } 488 489 /* 490 * Program TSHUT thresholds 491 * Step 1: set the thresholds to ~123C and 105C WKUP_VTM_MISC_CTRL2 492 * Step 2: WKUP_VTM_TMPSENS_CTRL_j set the MAXT_OUTRG_EN bit 493 * This is already taken care as per of init 494 * Step 3: WKUP_VTM_MISC_CTRL set the ANYMAXT_OUTRG_ALERT_EN bit 495 */ 496 high_max = k3_j72xx_bandgap_temp_to_adc_code(MAX_TEMP); 497 low_temp = k3_j72xx_bandgap_temp_to_adc_code(COOL_DOWN_TEMP); 498 499 writel((low_temp << 16) | high_max, data[0].bgp->cfg2_base + 500 K3_VTM_MISC_CTRL2_OFFSET); 501 mdelay(100); 502 writel(K3_VTM_ANYMAXT_OUTRG_ALERT_EN, data[0].bgp->cfg2_base + 503 K3_VTM_MISC_CTRL_OFFSET); 504 505 print_look_up_table(dev, ref_table); 506 /* 507 * Now that the derived_table has the appropriate look up values 508 * Free up the ref_table 509 */ 510 kfree(ref_table); 511 512 return 0; 513 514err_free_ref_table: 515 kfree(ref_table); 516 517err_alloc: 518 pm_runtime_put_sync(&pdev->dev); 519 pm_runtime_disable(&pdev->dev); 520 521 return ret; 522} 523 524static void k3_j72xx_bandgap_remove(struct platform_device *pdev) 525{ 526 pm_runtime_put_sync(&pdev->dev); 527 pm_runtime_disable(&pdev->dev); 528} 529 530static const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j721e_data = { 531 .has_errata_i2128 = true, 532}; 533 534static const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j7200_data = { 535 .has_errata_i2128 = false, 536}; 537 538static const struct of_device_id of_k3_j72xx_bandgap_match[] = { 539 { 540 .compatible = "ti,j721e-vtm", 541 .data = &k3_j72xx_bandgap_j721e_data, 542 }, 543 { 544 .compatible = "ti,j7200-vtm", 545 .data = &k3_j72xx_bandgap_j7200_data, 546 }, 547 { /* sentinel */ }, 548}; 549MODULE_DEVICE_TABLE(of, of_k3_j72xx_bandgap_match); 550 551static struct platform_driver k3_j72xx_bandgap_sensor_driver = { 552 .probe = k3_j72xx_bandgap_probe, 553 .remove_new = k3_j72xx_bandgap_remove, 554 .driver = { 555 .name = "k3-j72xx-soc-thermal", 556 .of_match_table = of_k3_j72xx_bandgap_match, 557 }, 558}; 559 560module_platform_driver(k3_j72xx_bandgap_sensor_driver); 561 562MODULE_DESCRIPTION("K3 bandgap temperature sensor driver"); 563MODULE_LICENSE("GPL"); 564MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>"); 565