GNU Linux-libre 4.19.314-gnu1
[releases.git] / drivers / cpufreq / imx6q-cpufreq.c
1 /*
2  * Copyright (C) 2013 Freescale Semiconductor, Inc.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8
9 #include <linux/clk.h>
10 #include <linux/cpu.h>
11 #include <linux/cpufreq.h>
12 #include <linux/cpu_cooling.h>
13 #include <linux/err.h>
14 #include <linux/module.h>
15 #include <linux/nvmem-consumer.h>
16 #include <linux/of.h>
17 #include <linux/of_address.h>
18 #include <linux/pm_opp.h>
19 #include <linux/platform_device.h>
20 #include <linux/regulator/consumer.h>
21
22 #define PU_SOC_VOLTAGE_NORMAL   1250000
23 #define PU_SOC_VOLTAGE_HIGH     1275000
24 #define FREQ_1P2_GHZ            1200000000
25
26 static struct regulator *arm_reg;
27 static struct regulator *pu_reg;
28 static struct regulator *soc_reg;
29
30 enum IMX6_CPUFREQ_CLKS {
31         ARM,
32         PLL1_SYS,
33         STEP,
34         PLL1_SW,
35         PLL2_PFD2_396M,
36         /* MX6UL requires two more clks */
37         PLL2_BUS,
38         SECONDARY_SEL,
39 };
40 #define IMX6Q_CPUFREQ_CLK_NUM           5
41 #define IMX6UL_CPUFREQ_CLK_NUM          7
42
43 static int num_clks;
44 static struct clk_bulk_data clks[] = {
45         { .id = "arm" },
46         { .id = "pll1_sys" },
47         { .id = "step" },
48         { .id = "pll1_sw" },
49         { .id = "pll2_pfd2_396m" },
50         { .id = "pll2_bus" },
51         { .id = "secondary_sel" },
52 };
53
54 static struct device *cpu_dev;
55 static struct thermal_cooling_device *cdev;
56 static bool free_opp;
57 static struct cpufreq_frequency_table *freq_table;
58 static unsigned int max_freq;
59 static unsigned int transition_latency;
60
61 static u32 *imx6_soc_volt;
62 static u32 soc_opp_count;
63
64 static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
65 {
66         struct dev_pm_opp *opp;
67         unsigned long freq_hz, volt, volt_old;
68         unsigned int old_freq, new_freq;
69         bool pll1_sys_temp_enabled = false;
70         int ret;
71
72         new_freq = freq_table[index].frequency;
73         freq_hz = new_freq * 1000;
74         old_freq = clk_get_rate(clks[ARM].clk) / 1000;
75
76         opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
77         if (IS_ERR(opp)) {
78                 dev_err(cpu_dev, "failed to find OPP for %ld\n", freq_hz);
79                 return PTR_ERR(opp);
80         }
81
82         volt = dev_pm_opp_get_voltage(opp);
83         dev_pm_opp_put(opp);
84
85         volt_old = regulator_get_voltage(arm_reg);
86
87         dev_dbg(cpu_dev, "%u MHz, %ld mV --> %u MHz, %ld mV\n",
88                 old_freq / 1000, volt_old / 1000,
89                 new_freq / 1000, volt / 1000);
90
91         /* scaling up?  scale voltage before frequency */
92         if (new_freq > old_freq) {
93                 if (!IS_ERR(pu_reg)) {
94                         ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
95                         if (ret) {
96                                 dev_err(cpu_dev, "failed to scale vddpu up: %d\n", ret);
97                                 return ret;
98                         }
99                 }
100                 ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
101                 if (ret) {
102                         dev_err(cpu_dev, "failed to scale vddsoc up: %d\n", ret);
103                         return ret;
104                 }
105                 ret = regulator_set_voltage_tol(arm_reg, volt, 0);
106                 if (ret) {
107                         dev_err(cpu_dev,
108                                 "failed to scale vddarm up: %d\n", ret);
109                         return ret;
110                 }
111         }
112
113         /*
114          * The setpoints are selected per PLL/PDF frequencies, so we need to
115          * reprogram PLL for frequency scaling.  The procedure of reprogramming
116          * PLL1 is as below.
117          * For i.MX6UL, it has a secondary clk mux, the cpu frequency change
118          * flow is slightly different from other i.MX6 OSC.
119          * The cpu frequeny change flow for i.MX6(except i.MX6UL) is as below:
120          *  - Enable pll2_pfd2_396m_clk and reparent pll1_sw_clk to it
121          *  - Reprogram pll1_sys_clk and reparent pll1_sw_clk back to it
122          *  - Disable pll2_pfd2_396m_clk
123          */
124         if (of_machine_is_compatible("fsl,imx6ul") ||
125             of_machine_is_compatible("fsl,imx6ull")) {
126                 /*
127                  * When changing pll1_sw_clk's parent to pll1_sys_clk,
128                  * CPU may run at higher than 528MHz, this will lead to
129                  * the system unstable if the voltage is lower than the
130                  * voltage of 528MHz, so lower the CPU frequency to one
131                  * half before changing CPU frequency.
132                  */
133                 clk_set_rate(clks[ARM].clk, (old_freq >> 1) * 1000);
134                 clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk);
135                 if (freq_hz > clk_get_rate(clks[PLL2_PFD2_396M].clk))
136                         clk_set_parent(clks[SECONDARY_SEL].clk,
137                                        clks[PLL2_BUS].clk);
138                 else
139                         clk_set_parent(clks[SECONDARY_SEL].clk,
140                                        clks[PLL2_PFD2_396M].clk);
141                 clk_set_parent(clks[STEP].clk, clks[SECONDARY_SEL].clk);
142                 clk_set_parent(clks[PLL1_SW].clk, clks[STEP].clk);
143                 if (freq_hz > clk_get_rate(clks[PLL2_BUS].clk)) {
144                         clk_set_rate(clks[PLL1_SYS].clk, new_freq * 1000);
145                         clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk);
146                 }
147         } else {
148                 clk_set_parent(clks[STEP].clk, clks[PLL2_PFD2_396M].clk);
149                 clk_set_parent(clks[PLL1_SW].clk, clks[STEP].clk);
150                 if (freq_hz > clk_get_rate(clks[PLL2_PFD2_396M].clk)) {
151                         clk_set_rate(clks[PLL1_SYS].clk, new_freq * 1000);
152                         clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk);
153                 } else {
154                         /* pll1_sys needs to be enabled for divider rate change to work. */
155                         pll1_sys_temp_enabled = true;
156                         clk_prepare_enable(clks[PLL1_SYS].clk);
157                 }
158         }
159
160         /* Ensure the arm clock divider is what we expect */
161         ret = clk_set_rate(clks[ARM].clk, new_freq * 1000);
162         if (ret) {
163                 int ret1;
164
165                 dev_err(cpu_dev, "failed to set clock rate: %d\n", ret);
166                 ret1 = regulator_set_voltage_tol(arm_reg, volt_old, 0);
167                 if (ret1)
168                         dev_warn(cpu_dev,
169                                  "failed to restore vddarm voltage: %d\n", ret1);
170                 return ret;
171         }
172
173         /* PLL1 is only needed until after ARM-PODF is set. */
174         if (pll1_sys_temp_enabled)
175                 clk_disable_unprepare(clks[PLL1_SYS].clk);
176
177         /* scaling down?  scale voltage after frequency */
178         if (new_freq < old_freq) {
179                 ret = regulator_set_voltage_tol(arm_reg, volt, 0);
180                 if (ret) {
181                         dev_warn(cpu_dev,
182                                  "failed to scale vddarm down: %d\n", ret);
183                         ret = 0;
184                 }
185                 ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
186                 if (ret) {
187                         dev_warn(cpu_dev, "failed to scale vddsoc down: %d\n", ret);
188                         ret = 0;
189                 }
190                 if (!IS_ERR(pu_reg)) {
191                         ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
192                         if (ret) {
193                                 dev_warn(cpu_dev, "failed to scale vddpu down: %d\n", ret);
194                                 ret = 0;
195                         }
196                 }
197         }
198
199         return 0;
200 }
201
202 static void imx6q_cpufreq_ready(struct cpufreq_policy *policy)
203 {
204         cdev = of_cpufreq_cooling_register(policy);
205
206         if (!cdev)
207                 dev_err(cpu_dev,
208                         "running cpufreq without cooling device: %ld\n",
209                         PTR_ERR(cdev));
210 }
211
212 static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
213 {
214         int ret;
215
216         policy->clk = clks[ARM].clk;
217         ret = cpufreq_generic_init(policy, freq_table, transition_latency);
218         policy->suspend_freq = max_freq;
219
220         return ret;
221 }
222
223 static int imx6q_cpufreq_exit(struct cpufreq_policy *policy)
224 {
225         cpufreq_cooling_unregister(cdev);
226
227         return 0;
228 }
229
230 static struct cpufreq_driver imx6q_cpufreq_driver = {
231         .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
232         .verify = cpufreq_generic_frequency_table_verify,
233         .target_index = imx6q_set_target,
234         .get = cpufreq_generic_get,
235         .init = imx6q_cpufreq_init,
236         .exit = imx6q_cpufreq_exit,
237         .name = "imx6q-cpufreq",
238         .ready = imx6q_cpufreq_ready,
239         .attr = cpufreq_generic_attr,
240         .suspend = cpufreq_generic_suspend,
241 };
242
243 static void imx6x_disable_freq_in_opp(struct device *dev, unsigned long freq)
244 {
245         int ret = dev_pm_opp_disable(dev, freq);
246
247         if (ret < 0 && ret != -ENODEV)
248                 dev_warn(dev, "failed to disable %ldMHz OPP\n", freq / 1000000);
249 }
250
251 #define OCOTP_CFG3                      0x440
252 #define OCOTP_CFG3_SPEED_SHIFT          16
253 #define OCOTP_CFG3_SPEED_1P2GHZ         0x3
254 #define OCOTP_CFG3_SPEED_996MHZ         0x2
255 #define OCOTP_CFG3_SPEED_852MHZ         0x1
256
257 static void imx6q_opp_check_speed_grading(struct device *dev)
258 {
259         struct device_node *np;
260         void __iomem *base;
261         u32 val;
262
263         np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-ocotp");
264         if (!np)
265                 return;
266
267         base = of_iomap(np, 0);
268         if (!base) {
269                 dev_err(dev, "failed to map ocotp\n");
270                 goto put_node;
271         }
272
273         /*
274          * SPEED_GRADING[1:0] defines the max speed of ARM:
275          * 2b'11: 1200000000Hz;
276          * 2b'10: 996000000Hz;
277          * 2b'01: 852000000Hz; -- i.MX6Q Only, exclusive with 996MHz.
278          * 2b'00: 792000000Hz;
279          * We need to set the max speed of ARM according to fuse map.
280          */
281         val = readl_relaxed(base + OCOTP_CFG3);
282         val >>= OCOTP_CFG3_SPEED_SHIFT;
283         val &= 0x3;
284
285         if (val < OCOTP_CFG3_SPEED_996MHZ)
286                 imx6x_disable_freq_in_opp(dev, 996000000);
287
288         if (of_machine_is_compatible("fsl,imx6q") ||
289             of_machine_is_compatible("fsl,imx6qp")) {
290                 if (val != OCOTP_CFG3_SPEED_852MHZ)
291                         imx6x_disable_freq_in_opp(dev, 852000000);
292
293                 if (val != OCOTP_CFG3_SPEED_1P2GHZ)
294                         imx6x_disable_freq_in_opp(dev, 1200000000);
295         }
296         iounmap(base);
297 put_node:
298         of_node_put(np);
299 }
300
301 #define OCOTP_CFG3_6UL_SPEED_696MHZ     0x2
302 #define OCOTP_CFG3_6ULL_SPEED_792MHZ    0x2
303 #define OCOTP_CFG3_6ULL_SPEED_900MHZ    0x3
304
305 static int imx6ul_opp_check_speed_grading(struct device *dev)
306 {
307         u32 val;
308         int ret = 0;
309
310         if (of_find_property(dev->of_node, "nvmem-cells", NULL)) {
311                 ret = nvmem_cell_read_u32(dev, "speed_grade", &val);
312                 if (ret)
313                         return ret;
314         } else {
315                 struct device_node *np;
316                 void __iomem *base;
317
318                 np = of_find_compatible_node(NULL, NULL, "fsl,imx6ul-ocotp");
319                 if (!np)
320                         np = of_find_compatible_node(NULL, NULL,
321                                                      "fsl,imx6ull-ocotp");
322                 if (!np)
323                         return -ENOENT;
324
325                 base = of_iomap(np, 0);
326                 of_node_put(np);
327                 if (!base) {
328                         dev_err(dev, "failed to map ocotp\n");
329                         return -EFAULT;
330                 }
331
332                 val = readl_relaxed(base + OCOTP_CFG3);
333                 iounmap(base);
334         }
335
336         /*
337          * Speed GRADING[1:0] defines the max speed of ARM:
338          * 2b'00: Reserved;
339          * 2b'01: 528000000Hz;
340          * 2b'10: 696000000Hz on i.MX6UL, 792000000Hz on i.MX6ULL;
341          * 2b'11: 900000000Hz on i.MX6ULL only;
342          * We need to set the max speed of ARM according to fuse map.
343          */
344         val >>= OCOTP_CFG3_SPEED_SHIFT;
345         val &= 0x3;
346
347         if (of_machine_is_compatible("fsl,imx6ul"))
348                 if (val != OCOTP_CFG3_6UL_SPEED_696MHZ)
349                         imx6x_disable_freq_in_opp(dev, 696000000);
350
351         if (of_machine_is_compatible("fsl,imx6ull")) {
352                 if (val < OCOTP_CFG3_6ULL_SPEED_792MHZ)
353                         imx6x_disable_freq_in_opp(dev, 792000000);
354
355                 if (val != OCOTP_CFG3_6ULL_SPEED_900MHZ)
356                         imx6x_disable_freq_in_opp(dev, 900000000);
357         }
358
359         return ret;
360 }
361
362 static int imx6q_cpufreq_probe(struct platform_device *pdev)
363 {
364         struct device_node *np;
365         struct dev_pm_opp *opp;
366         unsigned long min_volt, max_volt;
367         int num, ret;
368         const struct property *prop;
369         const __be32 *val;
370         u32 nr, i, j;
371
372         cpu_dev = get_cpu_device(0);
373         if (!cpu_dev) {
374                 pr_err("failed to get cpu0 device\n");
375                 return -ENODEV;
376         }
377
378         np = of_node_get(cpu_dev->of_node);
379         if (!np) {
380                 dev_err(cpu_dev, "failed to find cpu0 node\n");
381                 return -ENOENT;
382         }
383
384         if (of_machine_is_compatible("fsl,imx6ul") ||
385             of_machine_is_compatible("fsl,imx6ull"))
386                 num_clks = IMX6UL_CPUFREQ_CLK_NUM;
387         else
388                 num_clks = IMX6Q_CPUFREQ_CLK_NUM;
389
390         ret = clk_bulk_get(cpu_dev, num_clks, clks);
391         if (ret)
392                 goto put_node;
393
394         arm_reg = regulator_get(cpu_dev, "arm");
395         pu_reg = regulator_get_optional(cpu_dev, "pu");
396         soc_reg = regulator_get(cpu_dev, "soc");
397         if (PTR_ERR(arm_reg) == -EPROBE_DEFER ||
398                         PTR_ERR(soc_reg) == -EPROBE_DEFER ||
399                         PTR_ERR(pu_reg) == -EPROBE_DEFER) {
400                 ret = -EPROBE_DEFER;
401                 dev_dbg(cpu_dev, "regulators not ready, defer\n");
402                 goto put_reg;
403         }
404         if (IS_ERR(arm_reg) || IS_ERR(soc_reg)) {
405                 dev_err(cpu_dev, "failed to get regulators\n");
406                 ret = -ENOENT;
407                 goto put_reg;
408         }
409
410         ret = dev_pm_opp_of_add_table(cpu_dev);
411         if (ret < 0) {
412                 dev_err(cpu_dev, "failed to init OPP table: %d\n", ret);
413                 goto put_reg;
414         }
415
416         if (of_machine_is_compatible("fsl,imx6ul") ||
417             of_machine_is_compatible("fsl,imx6ull")) {
418                 ret = imx6ul_opp_check_speed_grading(cpu_dev);
419                 if (ret == -EPROBE_DEFER)
420                         return ret;
421                 if (ret) {
422                         dev_err(cpu_dev, "failed to read ocotp: %d\n",
423                                 ret);
424                         return ret;
425                 }
426         } else {
427                 imx6q_opp_check_speed_grading(cpu_dev);
428         }
429
430         /* Because we have added the OPPs here, we must free them */
431         free_opp = true;
432         num = dev_pm_opp_get_opp_count(cpu_dev);
433         if (num < 0) {
434                 ret = num;
435                 dev_err(cpu_dev, "no OPP table is found: %d\n", ret);
436                 goto out_free_opp;
437         }
438
439         ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
440         if (ret) {
441                 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
442                 goto out_free_opp;
443         }
444
445         /* Make imx6_soc_volt array's size same as arm opp number */
446         imx6_soc_volt = devm_kcalloc(cpu_dev, num, sizeof(*imx6_soc_volt),
447                                      GFP_KERNEL);
448         if (imx6_soc_volt == NULL) {
449                 ret = -ENOMEM;
450                 goto free_freq_table;
451         }
452
453         prop = of_find_property(np, "fsl,soc-operating-points", NULL);
454         if (!prop || !prop->value)
455                 goto soc_opp_out;
456
457         /*
458          * Each OPP is a set of tuples consisting of frequency and
459          * voltage like <freq-kHz vol-uV>.
460          */
461         nr = prop->length / sizeof(u32);
462         if (nr % 2 || (nr / 2) < num)
463                 goto soc_opp_out;
464
465         for (j = 0; j < num; j++) {
466                 val = prop->value;
467                 for (i = 0; i < nr / 2; i++) {
468                         unsigned long freq = be32_to_cpup(val++);
469                         unsigned long volt = be32_to_cpup(val++);
470                         if (freq_table[j].frequency == freq) {
471                                 imx6_soc_volt[soc_opp_count++] = volt;
472                                 break;
473                         }
474                 }
475         }
476
477 soc_opp_out:
478         /* use fixed soc opp volt if no valid soc opp info found in dtb */
479         if (soc_opp_count != num) {
480                 dev_warn(cpu_dev, "can NOT find valid fsl,soc-operating-points property in dtb, use default value!\n");
481                 for (j = 0; j < num; j++)
482                         imx6_soc_volt[j] = PU_SOC_VOLTAGE_NORMAL;
483                 if (freq_table[num - 1].frequency * 1000 == FREQ_1P2_GHZ)
484                         imx6_soc_volt[num - 1] = PU_SOC_VOLTAGE_HIGH;
485         }
486
487         if (of_property_read_u32(np, "clock-latency", &transition_latency))
488                 transition_latency = CPUFREQ_ETERNAL;
489
490         /*
491          * Calculate the ramp time for max voltage change in the
492          * VDDSOC and VDDPU regulators.
493          */
494         ret = regulator_set_voltage_time(soc_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
495         if (ret > 0)
496                 transition_latency += ret * 1000;
497         if (!IS_ERR(pu_reg)) {
498                 ret = regulator_set_voltage_time(pu_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
499                 if (ret > 0)
500                         transition_latency += ret * 1000;
501         }
502
503         /*
504          * OPP is maintained in order of increasing frequency, and
505          * freq_table initialised from OPP is therefore sorted in the
506          * same order.
507          */
508         max_freq = freq_table[--num].frequency;
509         opp = dev_pm_opp_find_freq_exact(cpu_dev,
510                                   freq_table[0].frequency * 1000, true);
511         min_volt = dev_pm_opp_get_voltage(opp);
512         dev_pm_opp_put(opp);
513         opp = dev_pm_opp_find_freq_exact(cpu_dev, max_freq * 1000, true);
514         max_volt = dev_pm_opp_get_voltage(opp);
515         dev_pm_opp_put(opp);
516
517         ret = regulator_set_voltage_time(arm_reg, min_volt, max_volt);
518         if (ret > 0)
519                 transition_latency += ret * 1000;
520
521         ret = cpufreq_register_driver(&imx6q_cpufreq_driver);
522         if (ret) {
523                 dev_err(cpu_dev, "failed register driver: %d\n", ret);
524                 goto free_freq_table;
525         }
526
527         of_node_put(np);
528         return 0;
529
530 free_freq_table:
531         dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
532 out_free_opp:
533         if (free_opp)
534                 dev_pm_opp_of_remove_table(cpu_dev);
535 put_reg:
536         if (!IS_ERR(arm_reg))
537                 regulator_put(arm_reg);
538         if (!IS_ERR(pu_reg))
539                 regulator_put(pu_reg);
540         if (!IS_ERR(soc_reg))
541                 regulator_put(soc_reg);
542
543         clk_bulk_put(num_clks, clks);
544 put_node:
545         of_node_put(np);
546
547         return ret;
548 }
549
550 static int imx6q_cpufreq_remove(struct platform_device *pdev)
551 {
552         cpufreq_unregister_driver(&imx6q_cpufreq_driver);
553         dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
554         if (free_opp)
555                 dev_pm_opp_of_remove_table(cpu_dev);
556         regulator_put(arm_reg);
557         if (!IS_ERR(pu_reg))
558                 regulator_put(pu_reg);
559         regulator_put(soc_reg);
560
561         clk_bulk_put(num_clks, clks);
562
563         return 0;
564 }
565
566 static struct platform_driver imx6q_cpufreq_platdrv = {
567         .driver = {
568                 .name   = "imx6q-cpufreq",
569         },
570         .probe          = imx6q_cpufreq_probe,
571         .remove         = imx6q_cpufreq_remove,
572 };
573 module_platform_driver(imx6q_cpufreq_platdrv);
574
575 MODULE_ALIAS("platform:imx6q-cpufreq");
576 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
577 MODULE_DESCRIPTION("Freescale i.MX6Q cpufreq driver");
578 MODULE_LICENSE("GPL");