cpufreq: imx6q: Fix handling EPROBE_DEFER from regulator
[linux-2.6-block.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{
652ed95d 164 policy->clk = arm_clk;
17922ddd 165 return cpufreq_generic_init(policy, freq_table, transition_latency);
1dd538f0
SG
166}
167
1dd538f0 168static struct cpufreq_driver imx6q_cpufreq_driver = {
ae6b4271 169 .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
4f6ba385 170 .verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7 171 .target_index = imx6q_set_target,
652ed95d 172 .get = cpufreq_generic_get,
1dd538f0 173 .init = imx6q_cpufreq_init,
1dd538f0 174 .name = "imx6q-cpufreq",
4f6ba385 175 .attr = cpufreq_generic_attr,
1dd538f0
SG
176};
177
178static int imx6q_cpufreq_probe(struct platform_device *pdev)
179{
180 struct device_node *np;
47d43ba7 181 struct dev_pm_opp *opp;
1dd538f0
SG
182 unsigned long min_volt, max_volt;
183 int num, ret;
b4573d1d
AH
184 const struct property *prop;
185 const __be32 *val;
186 u32 nr, i, j;
1dd538f0 187
b494b48d
SK
188 cpu_dev = get_cpu_device(0);
189 if (!cpu_dev) {
190 pr_err("failed to get cpu0 device\n");
191 return -ENODEV;
192 }
1dd538f0 193
cdc58d60 194 np = of_node_get(cpu_dev->of_node);
1dd538f0
SG
195 if (!np) {
196 dev_err(cpu_dev, "failed to find cpu0 node\n");
197 return -ENOENT;
198 }
199
f8269c19
PZ
200 arm_clk = clk_get(cpu_dev, "arm");
201 pll1_sys_clk = clk_get(cpu_dev, "pll1_sys");
202 pll1_sw_clk = clk_get(cpu_dev, "pll1_sw");
203 step_clk = clk_get(cpu_dev, "step");
204 pll2_pfd2_396m_clk = clk_get(cpu_dev, "pll2_pfd2_396m");
1dd538f0
SG
205 if (IS_ERR(arm_clk) || IS_ERR(pll1_sys_clk) || IS_ERR(pll1_sw_clk) ||
206 IS_ERR(step_clk) || IS_ERR(pll2_pfd2_396m_clk)) {
207 dev_err(cpu_dev, "failed to get clocks\n");
208 ret = -ENOENT;
f8269c19 209 goto put_clk;
1dd538f0
SG
210 }
211
a35fc5a3
BP
212 if (of_machine_is_compatible("fsl,imx6ul")) {
213 pll2_bus_clk = clk_get(cpu_dev, "pll2_bus");
214 secondary_sel_clk = clk_get(cpu_dev, "secondary_sel");
215 if (IS_ERR(pll2_bus_clk) || IS_ERR(secondary_sel_clk)) {
216 dev_err(cpu_dev, "failed to get clocks specific to imx6ul\n");
217 ret = -ENOENT;
218 goto put_clk;
219 }
220 }
221
f8269c19 222 arm_reg = regulator_get(cpu_dev, "arm");
22d0628a 223 pu_reg = regulator_get_optional(cpu_dev, "pu");
f8269c19 224 soc_reg = regulator_get(cpu_dev, "soc");
54cad2fc
IT
225 if (PTR_ERR(arm_reg) == -EPROBE_DEFER ||
226 PTR_ERR(soc_reg) == -EPROBE_DEFER ||
227 PTR_ERR(pu_reg) == -EPROBE_DEFER) {
228 ret = -EPROBE_DEFER;
229 dev_dbg(cpu_dev, "regulators not ready, defer\n");
230 goto put_reg;
231 }
22d0628a 232 if (IS_ERR(arm_reg) || IS_ERR(soc_reg)) {
1dd538f0
SG
233 dev_err(cpu_dev, "failed to get regulators\n");
234 ret = -ENOENT;
f8269c19 235 goto put_reg;
1dd538f0
SG
236 }
237
20b7cbe2
JT
238 /*
239 * We expect an OPP table supplied by platform.
240 * Just, incase the platform did not supply the OPP
241 * table, it will try to get it.
242 */
5d4879cd 243 num = dev_pm_opp_get_opp_count(cpu_dev);
1dd538f0 244 if (num < 0) {
8f8d37b2 245 ret = dev_pm_opp_of_add_table(cpu_dev);
20b7cbe2
JT
246 if (ret < 0) {
247 dev_err(cpu_dev, "failed to init OPP table: %d\n", ret);
f8269c19 248 goto put_reg;
20b7cbe2
JT
249 }
250
cc87b8a8
VK
251 /* Because we have added the OPPs here, we must free them */
252 free_opp = true;
253
20b7cbe2
JT
254 num = dev_pm_opp_get_opp_count(cpu_dev);
255 if (num < 0) {
256 ret = num;
257 dev_err(cpu_dev, "no OPP table is found: %d\n", ret);
cc87b8a8 258 goto out_free_opp;
20b7cbe2 259 }
1dd538f0
SG
260 }
261
5d4879cd 262 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
1dd538f0
SG
263 if (ret) {
264 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
f8269c19 265 goto put_reg;
1dd538f0
SG
266 }
267
b4573d1d
AH
268 /* Make imx6_soc_volt array's size same as arm opp number */
269 imx6_soc_volt = devm_kzalloc(cpu_dev, sizeof(*imx6_soc_volt) * num, GFP_KERNEL);
270 if (imx6_soc_volt == NULL) {
271 ret = -ENOMEM;
272 goto free_freq_table;
273 }
274
275 prop = of_find_property(np, "fsl,soc-operating-points", NULL);
276 if (!prop || !prop->value)
277 goto soc_opp_out;
278
279 /*
280 * Each OPP is a set of tuples consisting of frequency and
281 * voltage like <freq-kHz vol-uV>.
282 */
283 nr = prop->length / sizeof(u32);
284 if (nr % 2 || (nr / 2) < num)
285 goto soc_opp_out;
286
287 for (j = 0; j < num; j++) {
288 val = prop->value;
289 for (i = 0; i < nr / 2; i++) {
290 unsigned long freq = be32_to_cpup(val++);
291 unsigned long volt = be32_to_cpup(val++);
292 if (freq_table[j].frequency == freq) {
293 imx6_soc_volt[soc_opp_count++] = volt;
294 break;
295 }
296 }
297 }
298
299soc_opp_out:
300 /* use fixed soc opp volt if no valid soc opp info found in dtb */
301 if (soc_opp_count != num) {
302 dev_warn(cpu_dev, "can NOT find valid fsl,soc-operating-points property in dtb, use default value!\n");
303 for (j = 0; j < num; j++)
304 imx6_soc_volt[j] = PU_SOC_VOLTAGE_NORMAL;
305 if (freq_table[num - 1].frequency * 1000 == FREQ_1P2_GHZ)
306 imx6_soc_volt[num - 1] = PU_SOC_VOLTAGE_HIGH;
307 }
308
1dd538f0
SG
309 if (of_property_read_u32(np, "clock-latency", &transition_latency))
310 transition_latency = CPUFREQ_ETERNAL;
311
b4573d1d
AH
312 /*
313 * Calculate the ramp time for max voltage change in the
314 * VDDSOC and VDDPU regulators.
315 */
316 ret = regulator_set_voltage_time(soc_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
317 if (ret > 0)
318 transition_latency += ret * 1000;
22d0628a
AH
319 if (!IS_ERR(pu_reg)) {
320 ret = regulator_set_voltage_time(pu_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
321 if (ret > 0)
322 transition_latency += ret * 1000;
323 }
b4573d1d 324
1dd538f0
SG
325 /*
326 * OPP is maintained in order of increasing frequency, and
327 * freq_table initialised from OPP is therefore sorted in the
328 * same order.
329 */
5d4879cd 330 opp = dev_pm_opp_find_freq_exact(cpu_dev,
1dd538f0 331 freq_table[0].frequency * 1000, true);
5d4879cd 332 min_volt = dev_pm_opp_get_voltage(opp);
8a31d9d9 333 dev_pm_opp_put(opp);
5d4879cd 334 opp = dev_pm_opp_find_freq_exact(cpu_dev,
1dd538f0 335 freq_table[--num].frequency * 1000, true);
5d4879cd 336 max_volt = dev_pm_opp_get_voltage(opp);
8a31d9d9
VK
337 dev_pm_opp_put(opp);
338
1dd538f0
SG
339 ret = regulator_set_voltage_time(arm_reg, min_volt, max_volt);
340 if (ret > 0)
341 transition_latency += ret * 1000;
342
1dd538f0
SG
343 ret = cpufreq_register_driver(&imx6q_cpufreq_driver);
344 if (ret) {
345 dev_err(cpu_dev, "failed register driver: %d\n", ret);
346 goto free_freq_table;
347 }
348
349 of_node_put(np);
350 return 0;
351
352free_freq_table:
5d4879cd 353 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
cc87b8a8
VK
354out_free_opp:
355 if (free_opp)
8f8d37b2 356 dev_pm_opp_of_remove_table(cpu_dev);
f8269c19
PZ
357put_reg:
358 if (!IS_ERR(arm_reg))
359 regulator_put(arm_reg);
360 if (!IS_ERR(pu_reg))
361 regulator_put(pu_reg);
362 if (!IS_ERR(soc_reg))
363 regulator_put(soc_reg);
364put_clk:
365 if (!IS_ERR(arm_clk))
366 clk_put(arm_clk);
367 if (!IS_ERR(pll1_sys_clk))
368 clk_put(pll1_sys_clk);
369 if (!IS_ERR(pll1_sw_clk))
370 clk_put(pll1_sw_clk);
371 if (!IS_ERR(step_clk))
372 clk_put(step_clk);
373 if (!IS_ERR(pll2_pfd2_396m_clk))
374 clk_put(pll2_pfd2_396m_clk);
a35fc5a3
BP
375 if (!IS_ERR(pll2_bus_clk))
376 clk_put(pll2_bus_clk);
377 if (!IS_ERR(secondary_sel_clk))
378 clk_put(secondary_sel_clk);
1dd538f0
SG
379 of_node_put(np);
380 return ret;
381}
382
383static int imx6q_cpufreq_remove(struct platform_device *pdev)
384{
385 cpufreq_unregister_driver(&imx6q_cpufreq_driver);
5d4879cd 386 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
cc87b8a8 387 if (free_opp)
8f8d37b2 388 dev_pm_opp_of_remove_table(cpu_dev);
f8269c19 389 regulator_put(arm_reg);
22d0628a
AH
390 if (!IS_ERR(pu_reg))
391 regulator_put(pu_reg);
f8269c19
PZ
392 regulator_put(soc_reg);
393 clk_put(arm_clk);
394 clk_put(pll1_sys_clk);
395 clk_put(pll1_sw_clk);
396 clk_put(step_clk);
397 clk_put(pll2_pfd2_396m_clk);
a35fc5a3
BP
398 clk_put(pll2_bus_clk);
399 clk_put(secondary_sel_clk);
1dd538f0
SG
400
401 return 0;
402}
403
404static struct platform_driver imx6q_cpufreq_platdrv = {
405 .driver = {
406 .name = "imx6q-cpufreq",
1dd538f0
SG
407 },
408 .probe = imx6q_cpufreq_probe,
409 .remove = imx6q_cpufreq_remove,
410};
411module_platform_driver(imx6q_cpufreq_platdrv);
412
413MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
414MODULE_DESCRIPTION("Freescale i.MX6Q cpufreq driver");
415MODULE_LICENSE("GPL");