1 // SPDX-License-Identifier: GPL-2.0
3 * TI Bandgap temperature sensor driver for J72XX SoC Family
5 * Copyright (C) 2021 Texas Instruments Incorporated - http://www.ti.com/
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>
18 #include <linux/thermal.h>
20 #include <linux/delay.h>
21 #include <linux/slab.h>
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)
37 #define K3_VTM_CORRECTION_TEMP_CNT 3
40 #define PLUS30CREF 253
41 #define PLUS125CREF 730
42 #define PLUS150CREF 940
44 #define TABLE_SIZE 1024
45 #define MAX_TEMP 123000
46 #define COOL_DOWN_TEMP 105000
48 #define FACTORS_REDUCTION 13
49 static int *derived_table;
51 static int compute_value(int index, const s64 *factors, int nr_factors,
57 for (i = 0; i < nr_factors; i++)
58 value += factors[i] * int_pow(index, i);
60 return (int)div64_s64(value, int_pow(10, reduction));
63 static void init_table(int factors_size, int *table, const s64 *factors)
67 for (i = 0; i < TABLE_SIZE; i++)
68 table[i] = compute_value(i, factors, factors_size,
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
82 static void create_table_segments(struct err_values *err_vals, int seg,
85 int m = 0, c, num, den, i, err, idx1, idx2, err1, err2, ref1, ref2;
90 idx1 = err_vals->refs[seg];
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];
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
109 * Take care of divide by zero error if error values are same
110 * Or when the slope is 0
112 if (den != 0 && m != 0) {
113 for (i = idx1; i <= idx2; i++) {
115 if (((i + err) < 0) || ((i + err) >= TABLE_SIZE))
117 derived_table[i] = ref_table[i + err];
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))
123 derived_table[i] = ref_table[i + err1];
128 static int prep_lookup_table(struct err_values *err_vals, int *ref_table)
133 * Fill up the lookup table under 3 segments
134 * region -40C to +30C
135 * region +30C to +125C
136 * region +125C to +150C
138 for (seg = 0; seg < 3; seg++)
139 create_table_segments(err_vals, seg, ref_table);
141 /* Get to the first valid temperature */
143 while (!derived_table[i])
147 * Get to the last zero index and back fill the temperature for
151 /* 300 milli celsius steps */
153 derived_table[i] = derived_table[i + 1] - 300;
157 * Fill the last trailing 0s which are unfilled with increments of
158 * 100 milli celsius till 1023 code
161 while (!derived_table[i])
166 while (i < TABLE_SIZE) {
167 derived_table[i] = derived_table[i - 1] + inc * 100;
174 struct k3_thermal_data;
176 struct k3_j72xx_bandgap {
179 void __iomem *cfg2_base;
180 struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS];
183 /* common data structures */
184 struct k3_thermal_data {
185 struct k3_j72xx_bandgap *bgp;
190 static int two_cmp(int tmp, int mask)
196 /* Return negative value */
200 static unsigned int vtm_get_best_value(unsigned int s0, unsigned int s1,
203 int d01 = abs(s0 - s1);
204 int d02 = abs(s0 - s2);
205 int d12 = abs(s1 - s2);
207 if (d01 <= d02 && d01 <= d12)
208 return (s0 + s1) / 2;
210 if (d02 <= d01 && d02 <= d12)
211 return (s0 + s2) / 2;
213 return (s1 + s2) / 2;
216 static inline int k3_bgp_read_temp(struct k3_thermal_data *devdata,
219 struct k3_j72xx_bandgap *bgp;
220 unsigned int dtemp, s0, s1, s2;
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.
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);
240 if (dtemp < 0 || dtemp >= TABLE_SIZE)
243 *temp = derived_table[dtemp];
248 /* Get temperature callback function for thermal zone */
249 static int k3_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
251 return k3_bgp_read_temp(tz->devdata, temp);
254 static const struct thermal_zone_device_ops k3_of_thermal_ops = {
255 .get_temp = k3_thermal_get_temp,
258 static int k3_j72xx_bandgap_temp_to_adc_code(int temp)
260 int low = 0, high = TABLE_SIZE - 1, mid;
262 if (temp > 160000 || temp < -50000)
265 /* Binary search to find the adc code */
266 while (low < (high - 1)) {
267 mid = (low + high) / 2;
268 if (temp <= derived_table[mid])
277 static void get_efuse_values(int id, struct k3_thermal_data *data, int *err,
278 void __iomem *fuse_base)
281 int ct_offsets[5][K3_VTM_CORRECTION_TEMP_CNT] = {
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 }
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);
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);
309 tmp = readl(fuse_base + ct_offsets[id][i]);
311 tmp = tmp >> __ffs(ct_bm[id][i]);
313 /* Obtain the sign bit pow*/
314 pow = ct_bm[id][i] >> __ffs(ct_bm[id][i]);
319 /* Check for negative value */
321 /* 2's complement value */
322 tmp = two_cmp(tmp, ct_bm[id][i] >> __ffs(ct_bm[id][i]));
327 /* Err value for 150C is set to 0 */
331 static void print_look_up_table(struct device *dev, int *ref_table)
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]);
341 struct k3_j72xx_bandgap_data {
342 const bool has_errata_i2128;
345 static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
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;
357 struct err_values err_vals;
358 void __iomem *fuse_base;
360 const s64 golden_factors[] = {
368 const s64 pvt_wa_factors[] = {
374 bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL);
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);
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);
389 driver_data = of_device_get_match_data(dev);
391 workaround_needed = driver_data->has_errata_i2128;
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.
400 * https://www.ti.com/lit/er/sprz455c/sprz455c.pdf
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);
408 if ((readl(fuse_base) & 0xc0000000) == 0xc0000000)
409 workaround_needed = false;
412 dev_dbg(bgp->dev, "Work around %sneeded\n",
413 workaround_needed ? "" : "not ");
415 pm_runtime_enable(dev);
416 ret = pm_runtime_get_sync(dev);
418 pm_runtime_put_noidle(dev);
419 pm_runtime_disable(dev);
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);
428 data = devm_kcalloc(bgp->dev, cnt, sizeof(*data), GFP_KERNEL);
434 ref_table = kzalloc(sizeof(*ref_table) * TABLE_SIZE, GFP_KERNEL);
440 derived_table = devm_kzalloc(bgp->dev, sizeof(*derived_table) * TABLE_SIZE,
442 if (!derived_table) {
444 goto err_free_ref_table;
447 if (!workaround_needed)
448 init_table(5, ref_table, golden_factors);
450 init_table(3, ref_table, pvt_wa_factors);
452 /* Register the thermal sensors */
453 for (id = 0; id < cnt; id++) {
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;
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);
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);
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);
479 bgp->ts_data[id] = &data[id];
480 ti_thermal = devm_thermal_of_zone_register(bgp->dev, id, &data[id],
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;
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
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);
499 writel((low_temp << 16) | high_max, data[0].bgp->cfg2_base +
500 K3_VTM_MISC_CTRL2_OFFSET);
502 writel(K3_VTM_ANYMAXT_OUTRG_ALERT_EN, data[0].bgp->cfg2_base +
503 K3_VTM_MISC_CTRL_OFFSET);
505 platform_set_drvdata(pdev, bgp);
507 print_look_up_table(dev, ref_table);
509 * Now that the derived_table has the appropriate look up values
510 * Free up the ref_table
520 pm_runtime_put_sync(&pdev->dev);
521 pm_runtime_disable(&pdev->dev);
526 static int k3_j72xx_bandgap_remove(struct platform_device *pdev)
528 pm_runtime_put_sync(&pdev->dev);
529 pm_runtime_disable(&pdev->dev);
534 static const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j721e_data = {
535 .has_errata_i2128 = true,
538 static const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j7200_data = {
539 .has_errata_i2128 = false,
542 static const struct of_device_id of_k3_j72xx_bandgap_match[] = {
544 .compatible = "ti,j721e-vtm",
545 .data = &k3_j72xx_bandgap_j721e_data,
548 .compatible = "ti,j7200-vtm",
549 .data = &k3_j72xx_bandgap_j7200_data,
553 MODULE_DEVICE_TABLE(of, of_k3_j72xx_bandgap_match);
555 static struct platform_driver k3_j72xx_bandgap_sensor_driver = {
556 .probe = k3_j72xx_bandgap_probe,
557 .remove = k3_j72xx_bandgap_remove,
559 .name = "k3-j72xx-soc-thermal",
560 .of_match_table = of_k3_j72xx_bandgap_match,
564 module_platform_driver(k3_j72xx_bandgap_sensor_driver);
566 MODULE_DESCRIPTION("K3 bandgap temperature sensor driver");
567 MODULE_LICENSE("GPL");
568 MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");