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cpufreq: imx6q: Set max suspend_freq to avoid changes during suspend
[mirror_ubuntu-bionic-kernel.git] / drivers / cpufreq / imx6q-cpufreq.c
CommitLineData
1dd538f0
SG
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>
b494b48d 10#include <linux/cpu.h>
1dd538f0 11#include <linux/cpufreq.h>
1dd538f0
SG
12#include <linux/err.h>
13#include <linux/module.h>
14#include <linux/of.h>
e4db1c74 15#include <linux/pm_opp.h>
1dd538f0
SG
16#include <linux/platform_device.h>
17#include <linux/regulator/consumer.h>
18
19#define PU_SOC_VOLTAGE_NORMAL 1250000
20#define PU_SOC_VOLTAGE_HIGH 1275000
21#define FREQ_1P2_GHZ 1200000000
22
23static struct regulator *arm_reg;
24static struct regulator *pu_reg;
25static struct regulator *soc_reg;
26
27static struct clk *arm_clk;
28static struct clk *pll1_sys_clk;
29static struct clk *pll1_sw_clk;
30static struct clk *step_clk;
31static struct clk *pll2_pfd2_396m_clk;
32
a35fc5a3
BP
33/* clk used by i.MX6UL */
34static struct clk *pll2_bus_clk;
35static struct clk *secondary_sel_clk;
36
1dd538f0 37static struct device *cpu_dev;
cc87b8a8 38static bool free_opp;
1dd538f0
SG
39static struct cpufreq_frequency_table *freq_table;
40static unsigned int transition_latency;
41
b4573d1d
AH
42static u32 *imx6_soc_volt;
43static u32 soc_opp_count;
44
9c0ebcf7 45static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
1dd538f0 46{
47d43ba7 47 struct dev_pm_opp *opp;
1dd538f0 48 unsigned long freq_hz, volt, volt_old;
d4019f0a 49 unsigned int old_freq, new_freq;
1dd538f0
SG
50 int ret;
51
d4019f0a
VK
52 new_freq = freq_table[index].frequency;
53 freq_hz = new_freq * 1000;
54 old_freq = clk_get_rate(arm_clk) / 1000;
1dd538f0 55
5d4879cd 56 opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
1dd538f0 57 if (IS_ERR(opp)) {
1dd538f0
SG
58 dev_err(cpu_dev, "failed to find OPP for %ld\n", freq_hz);
59 return PTR_ERR(opp);
60 }
61
5d4879cd 62 volt = dev_pm_opp_get_voltage(opp);
8a31d9d9
VK
63 dev_pm_opp_put(opp);
64
1dd538f0
SG
65 volt_old = regulator_get_voltage(arm_reg);
66
67 dev_dbg(cpu_dev, "%u MHz, %ld mV --> %u MHz, %ld mV\n",
d4019f0a
VK
68 old_freq / 1000, volt_old / 1000,
69 new_freq / 1000, volt / 1000);
5a571c35 70
1dd538f0 71 /* scaling up? scale voltage before frequency */
d4019f0a 72 if (new_freq > old_freq) {
22d0628a
AH
73 if (!IS_ERR(pu_reg)) {
74 ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
75 if (ret) {
76 dev_err(cpu_dev, "failed to scale vddpu up: %d\n", ret);
77 return ret;
78 }
b4573d1d
AH
79 }
80 ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
81 if (ret) {
82 dev_err(cpu_dev, "failed to scale vddsoc up: %d\n", ret);
83 return ret;
84 }
1dd538f0
SG
85 ret = regulator_set_voltage_tol(arm_reg, volt, 0);
86 if (ret) {
87 dev_err(cpu_dev,
88 "failed to scale vddarm up: %d\n", ret);
d4019f0a 89 return ret;
1dd538f0 90 }
1dd538f0
SG
91 }
92
93 /*
94 * The setpoints are selected per PLL/PDF frequencies, so we need to
95 * reprogram PLL for frequency scaling. The procedure of reprogramming
96 * PLL1 is as below.
a35fc5a3
BP
97 * For i.MX6UL, it has a secondary clk mux, the cpu frequency change
98 * flow is slightly different from other i.MX6 OSC.
99 * The cpu frequeny change flow for i.MX6(except i.MX6UL) is as below:
1dd538f0
SG
100 * - Enable pll2_pfd2_396m_clk and reparent pll1_sw_clk to it
101 * - Reprogram pll1_sys_clk and reparent pll1_sw_clk back to it
102 * - Disable pll2_pfd2_396m_clk
103 */
a35fc5a3
BP
104 if (of_machine_is_compatible("fsl,imx6ul")) {
105 /*
106 * When changing pll1_sw_clk's parent to pll1_sys_clk,
107 * CPU may run at higher than 528MHz, this will lead to
108 * the system unstable if the voltage is lower than the
109 * voltage of 528MHz, so lower the CPU frequency to one
110 * half before changing CPU frequency.
111 */
112 clk_set_rate(arm_clk, (old_freq >> 1) * 1000);
1dd538f0 113 clk_set_parent(pll1_sw_clk, pll1_sys_clk);
a35fc5a3
BP
114 if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk))
115 clk_set_parent(secondary_sel_clk, pll2_bus_clk);
116 else
117 clk_set_parent(secondary_sel_clk, pll2_pfd2_396m_clk);
118 clk_set_parent(step_clk, secondary_sel_clk);
119 clk_set_parent(pll1_sw_clk, step_clk);
120 } else {
121 clk_set_parent(step_clk, pll2_pfd2_396m_clk);
122 clk_set_parent(pll1_sw_clk, step_clk);
123 if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk)) {
124 clk_set_rate(pll1_sys_clk, new_freq * 1000);
125 clk_set_parent(pll1_sw_clk, pll1_sys_clk);
126 }
1dd538f0
SG
127 }
128
129 /* Ensure the arm clock divider is what we expect */
d4019f0a 130 ret = clk_set_rate(arm_clk, new_freq * 1000);
1dd538f0
SG
131 if (ret) {
132 dev_err(cpu_dev, "failed to set clock rate: %d\n", ret);
133 regulator_set_voltage_tol(arm_reg, volt_old, 0);
d4019f0a 134 return ret;
1dd538f0
SG
135 }
136
137 /* scaling down? scale voltage after frequency */
d4019f0a 138 if (new_freq < old_freq) {
1dd538f0 139 ret = regulator_set_voltage_tol(arm_reg, volt, 0);
5a571c35 140 if (ret) {
1dd538f0
SG
141 dev_warn(cpu_dev,
142 "failed to scale vddarm down: %d\n", ret);
5a571c35
VK
143 ret = 0;
144 }
b4573d1d
AH
145 ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
146 if (ret) {
147 dev_warn(cpu_dev, "failed to scale vddsoc down: %d\n", ret);
148 ret = 0;
149 }
22d0628a
AH
150 if (!IS_ERR(pu_reg)) {
151 ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
152 if (ret) {
153 dev_warn(cpu_dev, "failed to scale vddpu down: %d\n", ret);
154 ret = 0;
155 }
1dd538f0
SG
156 }
157 }
158
d4019f0a 159 return 0;
1dd538f0
SG
160}
161
162static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
163{
5aa1599f
LC
164 int ret;
165
652ed95d 166 policy->clk = arm_clk;
5aa1599f
LC
167 ret = cpufreq_generic_init(policy, freq_table, transition_latency);
168 policy->suspend_freq = policy->max;
169
170 return ret;
1dd538f0
SG
171}
172
1dd538f0 173static struct cpufreq_driver imx6q_cpufreq_driver = {
ae6b4271 174 .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
4f6ba385 175 .verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7 176 .target_index = imx6q_set_target,
652ed95d 177 .get = cpufreq_generic_get,
1dd538f0 178 .init = imx6q_cpufreq_init,
1dd538f0 179 .name = "imx6q-cpufreq",
4f6ba385 180 .attr = cpufreq_generic_attr,
5aa1599f 181 .suspend = cpufreq_generic_suspend,
1dd538f0
SG
182};
183
184static int imx6q_cpufreq_probe(struct platform_device *pdev)
185{
186 struct device_node *np;
47d43ba7 187 struct dev_pm_opp *opp;
1dd538f0
SG
188 unsigned long min_volt, max_volt;
189 int num, ret;
b4573d1d
AH
190 const struct property *prop;
191 const __be32 *val;
192 u32 nr, i, j;
1dd538f0 193
b494b48d
SH
194 cpu_dev = get_cpu_device(0);
195 if (!cpu_dev) {
196 pr_err("failed to get cpu0 device\n");
197 return -ENODEV;
198 }
1dd538f0 199
cdc58d60 200 np = of_node_get(cpu_dev->of_node);
1dd538f0
SG
201 if (!np) {
202 dev_err(cpu_dev, "failed to find cpu0 node\n");
203 return -ENOENT;
204 }
205
f8269c19
PZ
206 arm_clk = clk_get(cpu_dev, "arm");
207 pll1_sys_clk = clk_get(cpu_dev, "pll1_sys");
208 pll1_sw_clk = clk_get(cpu_dev, "pll1_sw");
209 step_clk = clk_get(cpu_dev, "step");
210 pll2_pfd2_396m_clk = clk_get(cpu_dev, "pll2_pfd2_396m");
1dd538f0
SG
211 if (IS_ERR(arm_clk) || IS_ERR(pll1_sys_clk) || IS_ERR(pll1_sw_clk) ||
212 IS_ERR(step_clk) || IS_ERR(pll2_pfd2_396m_clk)) {
213 dev_err(cpu_dev, "failed to get clocks\n");
214 ret = -ENOENT;
f8269c19 215 goto put_clk;
1dd538f0
SG
216 }
217
a35fc5a3
BP
218 if (of_machine_is_compatible("fsl,imx6ul")) {
219 pll2_bus_clk = clk_get(cpu_dev, "pll2_bus");
220 secondary_sel_clk = clk_get(cpu_dev, "secondary_sel");
221 if (IS_ERR(pll2_bus_clk) || IS_ERR(secondary_sel_clk)) {
222 dev_err(cpu_dev, "failed to get clocks specific to imx6ul\n");
223 ret = -ENOENT;
224 goto put_clk;
225 }
226 }
227
f8269c19 228 arm_reg = regulator_get(cpu_dev, "arm");
22d0628a 229 pu_reg = regulator_get_optional(cpu_dev, "pu");
f8269c19 230 soc_reg = regulator_get(cpu_dev, "soc");
54cad2fc
IT
231 if (PTR_ERR(arm_reg) == -EPROBE_DEFER ||
232 PTR_ERR(soc_reg) == -EPROBE_DEFER ||
233 PTR_ERR(pu_reg) == -EPROBE_DEFER) {
234 ret = -EPROBE_DEFER;
235 dev_dbg(cpu_dev, "regulators not ready, defer\n");
236 goto put_reg;
237 }
22d0628a 238 if (IS_ERR(arm_reg) || IS_ERR(soc_reg)) {
1dd538f0
SG
239 dev_err(cpu_dev, "failed to get regulators\n");
240 ret = -ENOENT;
f8269c19 241 goto put_reg;
1dd538f0
SG
242 }
243
20b7cbe2
JT
244 /*
245 * We expect an OPP table supplied by platform.
246 * Just, incase the platform did not supply the OPP
247 * table, it will try to get it.
248 */
5d4879cd 249 num = dev_pm_opp_get_opp_count(cpu_dev);
1dd538f0 250 if (num < 0) {
8f8d37b2 251 ret = dev_pm_opp_of_add_table(cpu_dev);
20b7cbe2
JT
252 if (ret < 0) {
253 dev_err(cpu_dev, "failed to init OPP table: %d\n", ret);
f8269c19 254 goto put_reg;
20b7cbe2
JT
255 }
256
cc87b8a8
VK
257 /* Because we have added the OPPs here, we must free them */
258 free_opp = true;
259
20b7cbe2
JT
260 num = dev_pm_opp_get_opp_count(cpu_dev);
261 if (num < 0) {
262 ret = num;
263 dev_err(cpu_dev, "no OPP table is found: %d\n", ret);
cc87b8a8 264 goto out_free_opp;
20b7cbe2 265 }
1dd538f0
SG
266 }
267
5d4879cd 268 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
1dd538f0
SG
269 if (ret) {
270 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
f8269c19 271 goto put_reg;
1dd538f0
SG
272 }
273
b4573d1d
AH
274 /* Make imx6_soc_volt array's size same as arm opp number */
275 imx6_soc_volt = devm_kzalloc(cpu_dev, sizeof(*imx6_soc_volt) * num, GFP_KERNEL);
276 if (imx6_soc_volt == NULL) {
277 ret = -ENOMEM;
278 goto free_freq_table;
279 }
280
281 prop = of_find_property(np, "fsl,soc-operating-points", NULL);
282 if (!prop || !prop->value)
283 goto soc_opp_out;
284
285 /*
286 * Each OPP is a set of tuples consisting of frequency and
287 * voltage like <freq-kHz vol-uV>.
288 */
289 nr = prop->length / sizeof(u32);
290 if (nr % 2 || (nr / 2) < num)
291 goto soc_opp_out;
292
293 for (j = 0; j < num; j++) {
294 val = prop->value;
295 for (i = 0; i < nr / 2; i++) {
296 unsigned long freq = be32_to_cpup(val++);
297 unsigned long volt = be32_to_cpup(val++);
298 if (freq_table[j].frequency == freq) {
299 imx6_soc_volt[soc_opp_count++] = volt;
300 break;
301 }
302 }
303 }
304
305soc_opp_out:
306 /* use fixed soc opp volt if no valid soc opp info found in dtb */
307 if (soc_opp_count != num) {
308 dev_warn(cpu_dev, "can NOT find valid fsl,soc-operating-points property in dtb, use default value!\n");
309 for (j = 0; j < num; j++)
310 imx6_soc_volt[j] = PU_SOC_VOLTAGE_NORMAL;
311 if (freq_table[num - 1].frequency * 1000 == FREQ_1P2_GHZ)
312 imx6_soc_volt[num - 1] = PU_SOC_VOLTAGE_HIGH;
313 }
314
1dd538f0
SG
315 if (of_property_read_u32(np, "clock-latency", &transition_latency))
316 transition_latency = CPUFREQ_ETERNAL;
317
b4573d1d
AH
318 /*
319 * Calculate the ramp time for max voltage change in the
320 * VDDSOC and VDDPU regulators.
321 */
322 ret = regulator_set_voltage_time(soc_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
323 if (ret > 0)
324 transition_latency += ret * 1000;
22d0628a
AH
325 if (!IS_ERR(pu_reg)) {
326 ret = regulator_set_voltage_time(pu_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
327 if (ret > 0)
328 transition_latency += ret * 1000;
329 }
b4573d1d 330
1dd538f0
SG
331 /*
332 * OPP is maintained in order of increasing frequency, and
333 * freq_table initialised from OPP is therefore sorted in the
334 * same order.
335 */
5d4879cd 336 opp = dev_pm_opp_find_freq_exact(cpu_dev,
1dd538f0 337 freq_table[0].frequency * 1000, true);
5d4879cd 338 min_volt = dev_pm_opp_get_voltage(opp);
8a31d9d9 339 dev_pm_opp_put(opp);
5d4879cd 340 opp = dev_pm_opp_find_freq_exact(cpu_dev,
1dd538f0 341 freq_table[--num].frequency * 1000, true);
5d4879cd 342 max_volt = dev_pm_opp_get_voltage(opp);
8a31d9d9
VK
343 dev_pm_opp_put(opp);
344
1dd538f0
SG
345 ret = regulator_set_voltage_time(arm_reg, min_volt, max_volt);
346 if (ret > 0)
347 transition_latency += ret * 1000;
348
1dd538f0
SG
349 ret = cpufreq_register_driver(&imx6q_cpufreq_driver);
350 if (ret) {
351 dev_err(cpu_dev, "failed register driver: %d\n", ret);
352 goto free_freq_table;
353 }
354
355 of_node_put(np);
356 return 0;
357
358free_freq_table:
5d4879cd 359 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
cc87b8a8
VK
360out_free_opp:
361 if (free_opp)
8f8d37b2 362 dev_pm_opp_of_remove_table(cpu_dev);
f8269c19
PZ
363put_reg:
364 if (!IS_ERR(arm_reg))
365 regulator_put(arm_reg);
366 if (!IS_ERR(pu_reg))
367 regulator_put(pu_reg);
368 if (!IS_ERR(soc_reg))
369 regulator_put(soc_reg);
370put_clk:
371 if (!IS_ERR(arm_clk))
372 clk_put(arm_clk);
373 if (!IS_ERR(pll1_sys_clk))
374 clk_put(pll1_sys_clk);
375 if (!IS_ERR(pll1_sw_clk))
376 clk_put(pll1_sw_clk);
377 if (!IS_ERR(step_clk))
378 clk_put(step_clk);
379 if (!IS_ERR(pll2_pfd2_396m_clk))
380 clk_put(pll2_pfd2_396m_clk);
a35fc5a3
BP
381 if (!IS_ERR(pll2_bus_clk))
382 clk_put(pll2_bus_clk);
383 if (!IS_ERR(secondary_sel_clk))
384 clk_put(secondary_sel_clk);
1dd538f0
SG
385 of_node_put(np);
386 return ret;
387}
388
389static int imx6q_cpufreq_remove(struct platform_device *pdev)
390{
391 cpufreq_unregister_driver(&imx6q_cpufreq_driver);
5d4879cd 392 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
cc87b8a8 393 if (free_opp)
8f8d37b2 394 dev_pm_opp_of_remove_table(cpu_dev);
f8269c19 395 regulator_put(arm_reg);
22d0628a
AH
396 if (!IS_ERR(pu_reg))
397 regulator_put(pu_reg);
f8269c19
PZ
398 regulator_put(soc_reg);
399 clk_put(arm_clk);
400 clk_put(pll1_sys_clk);
401 clk_put(pll1_sw_clk);
402 clk_put(step_clk);
403 clk_put(pll2_pfd2_396m_clk);
a35fc5a3
BP
404 clk_put(pll2_bus_clk);
405 clk_put(secondary_sel_clk);
1dd538f0
SG
406
407 return 0;
408}
409
410static struct platform_driver imx6q_cpufreq_platdrv = {
411 .driver = {
412 .name = "imx6q-cpufreq",
1dd538f0
SG
413 },
414 .probe = imx6q_cpufreq_probe,
415 .remove = imx6q_cpufreq_remove,
416};
417module_platform_driver(imx6q_cpufreq_platdrv);
418
419MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
420MODULE_DESCRIPTION("Freescale i.MX6Q cpufreq driver");
421MODULE_LICENSE("GPL");