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
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 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
two_cmp(int tmp,int mask)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
vtm_get_best_value(unsigned int s0,unsigned int s1,unsigned int s2)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
k3_bgp_read_temp(struct k3_thermal_data * devdata,int * temp)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 */
k3_thermal_get_temp(struct thermal_zone_device * tz,int * temp)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
k3_j72xx_bandgap_temp_to_adc_code(int temp)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
get_efuse_values(int id,struct k3_thermal_data * data,int * err,struct k3_j72xx_bandgap * bgp)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
print_look_up_table(struct device * dev,int * ref_table)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
k3_j72xx_bandgap_probe(struct platform_device * pdev)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
k3_j72xx_bandgap_remove(struct platform_device * pdev)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