summaryrefslogtreecommitdiff
path: root/drivers/cpufreq/imx6q-cpufreq.c
blob: 47ccfa6b17b73080ae6ddca6d1da00ae1c6301a0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2013 Freescale Semiconductor, Inc.
 */

#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/nvmem-consumer.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/pm_opp.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>

#define PU_SOC_VOLTAGE_NORMAL	1250000
#define PU_SOC_VOLTAGE_HIGH	1275000
#define FREQ_1P2_GHZ		1200000000

static struct regulator *arm_reg;
static struct regulator *pu_reg;
static struct regulator *soc_reg;

enum IMX6_CPUFREQ_CLKS {
	ARM,
	PLL1_SYS,
	STEP,
	PLL1_SW,
	PLL2_PFD2_396M,
	/* MX6UL requires two more clks */
	PLL2_BUS,
	SECONDARY_SEL,
};
#define IMX6Q_CPUFREQ_CLK_NUM		5
#define IMX6UL_CPUFREQ_CLK_NUM		7

static int num_clks;
static struct clk_bulk_data clks[] = {
	{ .id = "arm" },
	{ .id = "pll1_sys" },
	{ .id = "step" },
	{ .id = "pll1_sw" },
	{ .id = "pll2_pfd2_396m" },
	{ .id = "pll2_bus" },
	{ .id = "secondary_sel" },
};

static struct device *cpu_dev;
static bool free_opp;
static struct cpufreq_frequency_table *freq_table;
static unsigned int max_freq;
static unsigned int transition_latency;

static u32 *imx6_soc_volt;
static u32 soc_opp_count;

static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
{
	struct dev_pm_opp *opp;
	unsigned long freq_hz, volt, volt_old;
	unsigned int old_freq, new_freq;
	bool pll1_sys_temp_enabled = false;
	int ret;

	new_freq = freq_table[index].frequency;
	freq_hz = new_freq * 1000;
	old_freq = clk_get_rate(clks[ARM].clk) / 1000;

	opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
	if (IS_ERR(opp)) {
		dev_err(cpu_dev, "failed to find OPP for %ld\n", freq_hz);
		return PTR_ERR(opp);
	}

	volt = dev_pm_opp_get_voltage(opp);
	dev_pm_opp_put(opp);

	volt_old = regulator_get_voltage(arm_reg);

	dev_dbg(cpu_dev, "%u MHz, %ld mV --> %u MHz, %ld mV\n",
		old_freq / 1000, volt_old / 1000,
		new_freq / 1000, volt / 1000);

	/* scaling up?  scale voltage before frequency */
	if (new_freq > old_freq) {
		if (!IS_ERR(pu_reg)) {
			ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
			if (ret) {
				dev_err(cpu_dev, "failed to scale vddpu up: %d\n", ret);
				return ret;
			}
		}
		ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
		if (ret) {
			dev_err(cpu_dev, "failed to scale vddsoc up: %d\n", ret);
			return ret;
		}
		ret = regulator_set_voltage_tol(arm_reg, volt, 0);
		if (ret) {
			dev_err(cpu_dev,
				"failed to scale vddarm up: %d\n", ret);
			return ret;
		}
	}

	/*
	 * The setpoints are selected per PLL/PDF frequencies, so we need to
	 * reprogram PLL for frequency scaling.  The procedure of reprogramming
	 * PLL1 is as below.
	 * For i.MX6UL, it has a secondary clk mux, the cpu frequency change
	 * flow is slightly different from other i.MX6 OSC.
	 * The cpu frequeny change flow for i.MX6(except i.MX6UL) is as below:
	 *  - Enable pll2_pfd2_396m_clk and reparent pll1_sw_clk to it
	 *  - Reprogram pll1_sys_clk and reparent pll1_sw_clk back to it
	 *  - Disable pll2_pfd2_396m_clk
	 */
	if (of_machine_is_compatible("fsl,imx6ul") ||
	    of_machine_is_compatible("fsl,imx6ull")) {
		/*
		 * When changing pll1_sw_clk's parent to pll1_sys_clk,
		 * CPU may run at higher than 528MHz, this will lead to
		 * the system unstable if the voltage is lower than the
		 * voltage of 528MHz, so lower the CPU frequency to one
		 * half before changing CPU frequency.
		 */
		clk_set_rate(clks[ARM].clk, (old_freq >> 1) * 1000);
		clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk);
		if (freq_hz > clk_get_rate(clks[PLL2_PFD2_396M].clk))
			clk_set_parent(clks[SECONDARY_SEL].clk,
				       clks[PLL2_BUS].clk);
		else
			clk_set_parent(clks[SECONDARY_SEL].clk,
				       clks[PLL2_PFD2_396M].clk);
		clk_set_parent(clks[STEP].clk, clks[SECONDARY_SEL].clk);
		clk_set_parent(clks[PLL1_SW].clk, clks[STEP].clk);
		if (freq_hz > clk_get_rate(clks[PLL2_BUS].clk)) {
			clk_set_rate(clks[PLL1_SYS].clk, new_freq * 1000);
			clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk);
		}
	} else {
		clk_set_parent(clks[STEP].clk, clks[PLL2_PFD2_396M].clk);
		clk_set_parent(clks[PLL1_SW].clk, clks[STEP].clk);
		if (freq_hz > clk_get_rate(clks[PLL2_PFD2_396M].clk)) {
			clk_set_rate(clks[PLL1_SYS].clk, new_freq * 1000);
			clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk);
		} else {
			/* pll1_sys needs to be enabled for divider rate change to work. */
			pll1_sys_temp_enabled = true;
			clk_prepare_enable(clks[PLL1_SYS].clk);
		}
	}

	/* Ensure the arm clock divider is what we expect */
	ret = clk_set_rate(clks[ARM].clk, new_freq * 1000);
	if (ret) {
		int ret1;

		dev_err(cpu_dev, "failed to set clock rate: %d\n", ret);
		ret1 = regulator_set_voltage_tol(arm_reg, volt_old, 0);
		if (ret1)
			dev_warn(cpu_dev,
				 "failed to restore vddarm voltage: %d\n", ret1);
		return ret;
	}

	/* PLL1 is only needed until after ARM-PODF is set. */
	if (pll1_sys_temp_enabled)
		clk_disable_unprepare(clks[PLL1_SYS].clk);

	/* scaling down?  scale voltage after frequency */
	if (new_freq < old_freq) {
		ret = regulator_set_voltage_tol(arm_reg, volt, 0);
		if (ret)
			dev_warn(cpu_dev,
				 "failed to scale vddarm down: %d\n", ret);
		ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
		if (ret)
			dev_warn(cpu_dev, "failed to scale vddsoc down: %d\n", ret);
		if (!IS_ERR(pu_reg)) {
			ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
			if (ret)
				dev_warn(cpu_dev, "failed to scale vddpu down: %d\n", ret);
		}
	}

	return 0;
}

static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
{
	int ret;

	policy->clk = clks[ARM].clk;
	ret = cpufreq_generic_init(policy, freq_table, transition_latency);
	policy->suspend_freq = max_freq;
	dev_pm_opp_of_register_em(policy->cpus);

	return ret;
}

static struct cpufreq_driver imx6q_cpufreq_driver = {
	.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK |
		 CPUFREQ_IS_COOLING_DEV,
	.verify = cpufreq_generic_frequency_table_verify,
	.target_index = imx6q_set_target,
	.get = cpufreq_generic_get,
	.init = imx6q_cpufreq_init,
	.name = "imx6q-cpufreq",
	.attr = cpufreq_generic_attr,
	.suspend = cpufreq_generic_suspend,
};

#define OCOTP_CFG3			0x440
#define OCOTP_CFG3_SPEED_SHIFT		16
#define OCOTP_CFG3_SPEED_1P2GHZ		0x3
#define OCOTP_CFG3_SPEED_996MHZ		0x2
#define OCOTP_CFG3_SPEED_852MHZ		0x1

static void imx6q_opp_check_speed_grading(struct device *dev)
{
	struct device_node *np;
	void __iomem *base;
	u32 val;

	np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-ocotp");
	if (!np)
		return;

	base = of_iomap(np, 0);
	if (!base) {
		dev_err(dev, "failed to map ocotp\n");
		goto put_node;
	}

	/*
	 * SPEED_GRADING[1:0] defines the max speed of ARM:
	 * 2b'11: 1200000000Hz;
	 * 2b'10: 996000000Hz;
	 * 2b'01: 852000000Hz; -- i.MX6Q Only, exclusive with 996MHz.
	 * 2b'00: 792000000Hz;
	 * We need to set the max speed of ARM according to fuse map.
	 */
	val = readl_relaxed(base + OCOTP_CFG3);
	val >>= OCOTP_CFG3_SPEED_SHIFT;
	val &= 0x3;

	if (val < OCOTP_CFG3_SPEED_996MHZ)
		if (dev_pm_opp_disable(dev, 996000000))
			dev_warn(dev, "failed to disable 996MHz OPP\n");

	if (of_machine_is_compatible("fsl,imx6q") ||
	    of_machine_is_compatible("fsl,imx6qp")) {
		if (val != OCOTP_CFG3_SPEED_852MHZ)
			if (dev_pm_opp_disable(dev, 852000000))
				dev_warn(dev, "failed to disable 852MHz OPP\n");
		if (val != OCOTP_CFG3_SPEED_1P2GHZ)
			if (dev_pm_opp_disable(dev, 1200000000))
				dev_warn(dev, "failed to disable 1.2GHz OPP\n");
	}
	iounmap(base);
put_node:
	of_node_put(np);
}

#define OCOTP_CFG3_6UL_SPEED_696MHZ	0x2
#define OCOTP_CFG3_6ULL_SPEED_792MHZ	0x2
#define OCOTP_CFG3_6ULL_SPEED_900MHZ	0x3

static int imx6ul_opp_check_speed_grading(struct device *dev)
{
	u32 val;
	int ret = 0;

	if (of_find_property(dev->of_node, "nvmem-cells", NULL)) {
		ret = nvmem_cell_read_u32(dev, "speed_grade", &val);
		if (ret)
			return ret;
	} else {
		struct device_node *np;
		void __iomem *base;

		np = of_find_compatible_node(NULL, NULL, "fsl,imx6ul-ocotp");
		if (!np)
			return -ENOENT;

		base = of_iomap(np, 0);
		of_node_put(np);
		if (!base) {
			dev_err(dev, "failed to map ocotp\n");
			return -EFAULT;
		}

		val = readl_relaxed(base + OCOTP_CFG3);
		iounmap(base);
	}

	/*
	 * Speed GRADING[1:0] defines the max speed of ARM:
	 * 2b'00: Reserved;
	 * 2b'01: 528000000Hz;
	 * 2b'10: 696000000Hz on i.MX6UL, 792000000Hz on i.MX6ULL;
	 * 2b'11: 900000000Hz on i.MX6ULL only;
	 * We need to set the max speed of ARM according to fuse map.
	 */
	val >>= OCOTP_CFG3_SPEED_SHIFT;
	val &= 0x3;

	if (of_machine_is_compatible("fsl,imx6ul")) {
		if (val != OCOTP_CFG3_6UL_SPEED_696MHZ)
			if (dev_pm_opp_disable(dev, 696000000))
				dev_warn(dev, "failed to disable 696MHz OPP\n");
	}

	if (of_machine_is_compatible("fsl,imx6ull")) {
		if (val != OCOTP_CFG3_6ULL_SPEED_792MHZ)
			if (dev_pm_opp_disable(dev, 792000000))
				dev_warn(dev, "failed to disable 792MHz OPP\n");

		if (val != OCOTP_CFG3_6ULL_SPEED_900MHZ)
			if (dev_pm_opp_disable(dev, 900000000))
				dev_warn(dev, "failed to disable 900MHz OPP\n");
	}

	return ret;
}

static int imx6q_cpufreq_probe(struct platform_device *pdev)
{
	struct device_node *np;
	struct dev_pm_opp *opp;
	unsigned long min_volt, max_volt;
	int num, ret;
	const struct property *prop;
	const __be32 *val;
	u32 nr, i, j;

	cpu_dev = get_cpu_device(0);
	if (!cpu_dev) {
		pr_err("failed to get cpu0 device\n");
		return -ENODEV;
	}

	np = of_node_get(cpu_dev->of_node);
	if (!np) {
		dev_err(cpu_dev, "failed to find cpu0 node\n");
		return -ENOENT;
	}

	if (of_machine_is_compatible("fsl,imx6ul") ||
	    of_machine_is_compatible("fsl,imx6ull"))
		num_clks = IMX6UL_CPUFREQ_CLK_NUM;
	else
		num_clks = IMX6Q_CPUFREQ_CLK_NUM;

	ret = clk_bulk_get(cpu_dev, num_clks, clks);
	if (ret)
		goto put_node;

	arm_reg = regulator_get(cpu_dev, "arm");
	pu_reg = regulator_get_optional(cpu_dev, "pu");
	soc_reg = regulator_get(cpu_dev, "soc");
	if (PTR_ERR(arm_reg) == -EPROBE_DEFER ||
			PTR_ERR(soc_reg) == -EPROBE_DEFER ||
			PTR_ERR(pu_reg) == -EPROBE_DEFER) {
		ret = -EPROBE_DEFER;
		dev_dbg(cpu_dev, "regulators not ready, defer\n");
		goto put_reg;
	}
	if (IS_ERR(arm_reg) || IS_ERR(soc_reg)) {
		dev_err(cpu_dev, "failed to get regulators\n");
		ret = -ENOENT;
		goto put_reg;
	}

	ret = dev_pm_opp_of_add_table(cpu_dev);
	if (ret < 0) {
		dev_err(cpu_dev, "failed to init OPP table: %d\n", ret);
		goto put_reg;
	}

	if (of_machine_is_compatible("fsl,imx6ul") ||
	    of_machine_is_compatible("fsl,imx6ull")) {
		ret = imx6ul_opp_check_speed_grading(cpu_dev);
		if (ret) {
			if (ret == -EPROBE_DEFER)
				goto put_node;

			dev_err(cpu_dev, "failed to read ocotp: %d\n",
				ret);
			goto put_node;
		}
	} else {
		imx6q_opp_check_speed_grading(cpu_dev);
	}

	/* Because we have added the OPPs here, we must free them */
	free_opp = true;
	num = dev_pm_opp_get_opp_count(cpu_dev);
	if (num < 0) {
		ret = num;
		dev_err(cpu_dev, "no OPP table is found: %d\n", ret);
		goto out_free_opp;
	}

	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
	if (ret) {
		dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
		goto out_free_opp;
	}

	/* Make imx6_soc_volt array's size same as arm opp number */
	imx6_soc_volt = devm_kcalloc(cpu_dev, num, sizeof(*imx6_soc_volt),
				     GFP_KERNEL);
	if (imx6_soc_volt == NULL) {
		ret = -ENOMEM;
		goto free_freq_table;
	}

	prop = of_find_property(np, "fsl,soc-operating-points", NULL);
	if (!prop || !prop->value)
		goto soc_opp_out;

	/*
	 * Each OPP is a set of tuples consisting of frequency and
	 * voltage like <freq-kHz vol-uV>.
	 */
	nr = prop->length / sizeof(u32);
	if (nr % 2 || (nr / 2) < num)
		goto soc_opp_out;

	for (j = 0; j < num; j++) {
		val = prop->value;
		for (i = 0; i < nr / 2; i++) {
			unsigned long freq = be32_to_cpup(val++);
			unsigned long volt = be32_to_cpup(val++);
			if (freq_table[j].frequency == freq) {
				imx6_soc_volt[soc_opp_count++] = volt;
				break;
			}
		}
	}

soc_opp_out:
	/* use fixed soc opp volt if no valid soc opp info found in dtb */
	if (soc_opp_count != num) {
		dev_warn(cpu_dev, "can NOT find valid fsl,soc-operating-points property in dtb, use default value!\n");
		for (j = 0; j < num; j++)
			imx6_soc_volt[j] = PU_SOC_VOLTAGE_NORMAL;
		if (freq_table[num - 1].frequency * 1000 == FREQ_1P2_GHZ)
			imx6_soc_volt[num - 1] = PU_SOC_VOLTAGE_HIGH;
	}

	if (of_property_read_u32(np, "clock-latency", &transition_latency))
		transition_latency = CPUFREQ_ETERNAL;

	/*
	 * Calculate the ramp time for max voltage change in the
	 * VDDSOC and VDDPU regulators.
	 */
	ret = regulator_set_voltage_time(soc_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
	if (ret > 0)
		transition_latency += ret * 1000;
	if (!IS_ERR(pu_reg)) {
		ret = regulator_set_voltage_time(pu_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
		if (ret > 0)
			transition_latency += ret * 1000;
	}

	/*
	 * OPP is maintained in order of increasing frequency, and
	 * freq_table initialised from OPP is therefore sorted in the
	 * same order.
	 */
	max_freq = freq_table[--num].frequency;
	opp = dev_pm_opp_find_freq_exact(cpu_dev,
				  freq_table[0].frequency * 1000, true);
	min_volt = dev_pm_opp_get_voltage(opp);
	dev_pm_opp_put(opp);
	opp = dev_pm_opp_find_freq_exact(cpu_dev, max_freq * 1000, true);
	max_volt = dev_pm_opp_get_voltage(opp);
	dev_pm_opp_put(opp);

	ret = regulator_set_voltage_time(arm_reg, min_volt, max_volt);
	if (ret > 0)
		transition_latency += ret * 1000;

	ret = cpufreq_register_driver(&imx6q_cpufreq_driver);
	if (ret) {
		dev_err(cpu_dev, "failed register driver: %d\n", ret);
		goto free_freq_table;
	}

	of_node_put(np);
	return 0;

free_freq_table:
	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
out_free_opp:
	if (free_opp)
		dev_pm_opp_of_remove_table(cpu_dev);
put_reg:
	if (!IS_ERR(arm_reg))
		regulator_put(arm_reg);
	if (!IS_ERR(pu_reg))
		regulator_put(pu_reg);
	if (!IS_ERR(soc_reg))
		regulator_put(soc_reg);

	clk_bulk_put(num_clks, clks);
put_node:
	of_node_put(np);

	return ret;
}

static int imx6q_cpufreq_remove(struct platform_device *pdev)
{
	cpufreq_unregister_driver(&imx6q_cpufreq_driver);
	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
	if (free_opp)
		dev_pm_opp_of_remove_table(cpu_dev);
	regulator_put(arm_reg);
	if (!IS_ERR(pu_reg))
		regulator_put(pu_reg);
	regulator_put(soc_reg);

	clk_bulk_put(num_clks, clks);

	return 0;
}

static struct platform_driver imx6q_cpufreq_platdrv = {
	.driver = {
		.name	= "imx6q-cpufreq",
	},
	.probe		= imx6q_cpufreq_probe,
	.remove		= imx6q_cpufreq_remove,
};
module_platform_driver(imx6q_cpufreq_platdrv);

MODULE_ALIAS("platform:imx6q-cpufreq");
MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
MODULE_DESCRIPTION("Freescale i.MX6Q cpufreq driver");
MODULE_LICENSE("GPL");