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
49 static int *derived_table;
50
compute_value(int index,const s64 * factors,int nr_factors,int reduction)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
init_table(int factors_size,int * table,const s64 * factors)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
create_table_segments(struct err_values * err_vals,int seg,int * ref_table)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
prep_lookup_table(struct err_values * err_vals,int * ref_table)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 struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS];
181 };
182
183 /* common data structures */
184 struct k3_thermal_data {
185 struct k3_j72xx_bandgap *bgp;
186 u32 ctrl_offset;
187 u32 stat_offset;
188 };
189
two_cmp(int tmp,int mask)190 static 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
vtm_get_best_value(unsigned int s0,unsigned int s1,unsigned int s2)200 static 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
k3_bgp_read_temp(struct k3_thermal_data * devdata,int * temp)216 static 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 */
k3_thermal_get_temp(struct thermal_zone_device * tz,int * temp)249 static 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
254 static const struct thermal_zone_device_ops k3_of_thermal_ops = {
255 .get_temp = k3_thermal_get_temp,
256 };
257
k3_j72xx_bandgap_temp_to_adc_code(int temp)258 static 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
get_efuse_values(int id,struct k3_thermal_data * data,int * err,void __iomem * fuse_base)277 static 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
print_look_up_table(struct device * dev,int * ref_table)331 static 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
341 struct k3_j72xx_bandgap_data {
342 const bool has_errata_i2128;
343 };
344
k3_j72xx_bandgap_probe(struct platform_device * pdev)345 static 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
514 err_free_ref_table:
515 kfree(ref_table);
516
517 err_alloc:
518 pm_runtime_put_sync(&pdev->dev);
519 pm_runtime_disable(&pdev->dev);
520
521 return ret;
522 }
523
k3_j72xx_bandgap_remove(struct platform_device * pdev)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 static const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j721e_data = {
533 .has_errata_i2128 = true,
534 };
535
536 static const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j7200_data = {
537 .has_errata_i2128 = false,
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