aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/mach-s5pv210/cpufreq.c
blob: a6f22920a2c20bd40fbdb9bfebbbb111af4f1fbc (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
/* linux/arch/arm/mach-s5pv210/cpufreq.c
 *
 * Copyright (c) 2010 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 *
 * CPU frequency scaling for S5PC110/S5PV210
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/cpufreq.h>

#include <mach/map.h>
#include <mach/regs-clock.h>

static struct clk *cpu_clk;
static struct clk *dmc0_clk;
static struct clk *dmc1_clk;
static struct cpufreq_freqs freqs;

/* APLL M,P,S values for 1G/800Mhz */
#define APLL_VAL_1000	((1 << 31) | (125 << 16) | (3 << 8) | 1)
#define APLL_VAL_800	((1 << 31) | (100 << 16) | (3 << 8) | 1)

/*
 * DRAM configurations to calculate refresh counter for changing
 * frequency of memory.
 */
struct dram_conf {
	unsigned long freq;	/* HZ */
	unsigned long refresh;	/* DRAM refresh counter * 1000 */
};

/* DRAM configuration (DMC0 and DMC1) */
static struct dram_conf s5pv210_dram_conf[2];

enum perf_level {
	L0, L1, L2, L3, L4,
};

enum s5pv210_mem_type {
	LPDDR	= 0x1,
	LPDDR2	= 0x2,
	DDR2	= 0x4,
};

enum s5pv210_dmc_port {
	DMC0 = 0,
	DMC1,
};

static struct cpufreq_frequency_table s5pv210_freq_table[] = {
	{L0, 1000*1000},
	{L1, 800*1000},
	{L2, 400*1000},
	{L3, 200*1000},
	{L4, 100*1000},
	{0, CPUFREQ_TABLE_END},
};

static u32 clkdiv_val[5][11] = {
	/*
	 * Clock divider value for following
	 * { APLL, A2M, HCLK_MSYS, PCLK_MSYS,
	 *   HCLK_DSYS, PCLK_DSYS, HCLK_PSYS, PCLK_PSYS,
	 *   ONEDRAM, MFC, G3D }
	 */

	/* L0 : [1000/200/100][166/83][133/66][200/200] */
	{0, 4, 4, 1, 3, 1, 4, 1, 3, 0, 0},

	/* L1 : [800/200/100][166/83][133/66][200/200] */
	{0, 3, 3, 1, 3, 1, 4, 1, 3, 0, 0},

	/* L2 : [400/200/100][166/83][133/66][200/200] */
	{1, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},

	/* L3 : [200/200/100][166/83][133/66][200/200] */
	{3, 3, 1, 1, 3, 1, 4, 1, 3, 0, 0},

	/* L4 : [100/100/100][83/83][66/66][100/100] */
	{7, 7, 0, 0, 7, 0, 9, 0, 7, 0, 0},
};

/*
 * This function set DRAM refresh counter
 * accoriding to operating frequency of DRAM
 * ch: DMC port number 0 or 1
 * freq: Operating frequency of DRAM(KHz)
 */
static void s5pv210_set_refresh(enum s5pv210_dmc_port ch, unsigned long freq)
{
	unsigned long tmp, tmp1;
	void __iomem *reg = NULL;

	if (ch == DMC0)
		reg = (S5P_VA_DMC0 + 0x30);
	else if (ch == DMC1)
		reg = (S5P_VA_DMC1 + 0x30);
	else
		printk(KERN_ERR "Cannot find DMC port\n");

	/* Find current DRAM frequency */
	tmp = s5pv210_dram_conf[ch].freq;

	do_div(tmp, freq);

	tmp1 = s5pv210_dram_conf[ch].refresh;

	do_div(tmp1, tmp);

	__raw_writel(tmp1, reg);
}

int s5pv210_verify_speed(struct cpufreq_policy *policy)
{
	if (policy->cpu)
		return -EINVAL;

	return cpufreq_frequency_table_verify(policy, s5pv210_freq_table);
}

unsigned int s5pv210_getspeed(unsigned int cpu)
{
	if (cpu)
		return 0;

	return clk_get_rate(cpu_clk) / 1000;
}

static int s5pv210_target(struct cpufreq_policy *policy,
			  unsigned int target_freq,
			  unsigned int relation)
{
	unsigned long reg;
	unsigned int index, priv_index;
	unsigned int pll_changing = 0;
	unsigned int bus_speed_changing = 0;

	freqs.old = s5pv210_getspeed(0);

	if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
					   target_freq, relation, &index))
		return -EINVAL;

	freqs.new = s5pv210_freq_table[index].frequency;
	freqs.cpu = 0;

	if (freqs.new == freqs.old)
		return 0;

	/* Finding current running level index */
	if (cpufreq_frequency_table_target(policy, s5pv210_freq_table,
					   freqs.old, relation, &priv_index))
		return -EINVAL;

	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	if (freqs.new > freqs.old) {
		/* Voltage up: will be implemented */
	}

	/* Check if there need to change PLL */
	if ((index == L0) || (priv_index == L0))
		pll_changing = 1;

	/* Check if there need to change System bus clock */
	if ((index == L4) || (priv_index == L4))
		bus_speed_changing = 1;

	if (bus_speed_changing) {
		/*
		 * Reconfigure DRAM refresh counter value for minimum
		 * temporary clock while changing divider.
		 * expected clock is 83Mhz : 7.8usec/(1/83Mhz) = 0x287
		 */
		if (pll_changing)
			s5pv210_set_refresh(DMC1, 83000);
		else
			s5pv210_set_refresh(DMC1, 100000);

		s5pv210_set_refresh(DMC0, 83000);
	}

	/*
	 * APLL should be changed in this level
	 * APLL -> MPLL(for stable transition) -> APLL
	 * Some clock source's clock API are not prepared.
	 * Do not use clock API in below code.
	 */
	if (pll_changing) {
		/*
		 * 1. Temporary Change divider for MFC and G3D
		 * SCLKA2M(200/1=200)->(200/4=50)Mhz
		 */
		reg = __raw_readl(S5P_CLK_DIV2);
		reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
		reg |= (3 << S5P_CLKDIV2_G3D_SHIFT) |
			(3 << S5P_CLKDIV2_MFC_SHIFT);
		__raw_writel(reg, S5P_CLK_DIV2);

		/* For MFC, G3D dividing */
		do {
			reg = __raw_readl(S5P_CLKDIV_STAT0);
		} while (reg & ((1 << 16) | (1 << 17)));

		/*
		 * 2. Change SCLKA2M(200Mhz)to SCLKMPLL in MFC_MUX, G3D MUX
		 * (200/4=50)->(667/4=166)Mhz
		 */
		reg = __raw_readl(S5P_CLK_SRC2);
		reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
		reg |= (1 << S5P_CLKSRC2_G3D_SHIFT) |
			(1 << S5P_CLKSRC2_MFC_SHIFT);
		__raw_writel(reg, S5P_CLK_SRC2);

		do {
			reg = __raw_readl(S5P_CLKMUX_STAT1);
		} while (reg & ((1 << 7) | (1 << 3)));

		/*
		 * 3. DMC1 refresh count for 133Mhz if (index == L4) is
		 * true refresh counter is already programed in upper
		 * code. 0x287@83Mhz
		 */
		if (!bus_speed_changing)
			s5pv210_set_refresh(DMC1, 133000);

		/* 4. SCLKAPLL -> SCLKMPLL */
		reg = __raw_readl(S5P_CLK_SRC0);
		reg &= ~(S5P_CLKSRC0_MUX200_MASK);
		reg |= (0x1 << S5P_CLKSRC0_MUX200_SHIFT);
		__raw_writel(reg, S5P_CLK_SRC0);

		do {
			reg = __raw_readl(S5P_CLKMUX_STAT0);
		} while (reg & (0x1 << 18));

	}

	/* Change divider */
	reg = __raw_readl(S5P_CLK_DIV0);

	reg &= ~(S5P_CLKDIV0_APLL_MASK | S5P_CLKDIV0_A2M_MASK |
		S5P_CLKDIV0_HCLK200_MASK | S5P_CLKDIV0_PCLK100_MASK |
		S5P_CLKDIV0_HCLK166_MASK | S5P_CLKDIV0_PCLK83_MASK |
		S5P_CLKDIV0_HCLK133_MASK | S5P_CLKDIV0_PCLK66_MASK);

	reg |= ((clkdiv_val[index][0] << S5P_CLKDIV0_APLL_SHIFT) |
		(clkdiv_val[index][1] << S5P_CLKDIV0_A2M_SHIFT) |
		(clkdiv_val[index][2] << S5P_CLKDIV0_HCLK200_SHIFT) |
		(clkdiv_val[index][3] << S5P_CLKDIV0_PCLK100_SHIFT) |
		(clkdiv_val[index][4] << S5P_CLKDIV0_HCLK166_SHIFT) |
		(clkdiv_val[index][5] << S5P_CLKDIV0_PCLK83_SHIFT) |
		(clkdiv_val[index][6] << S5P_CLKDIV0_HCLK133_SHIFT) |
		(clkdiv_val[index][7] << S5P_CLKDIV0_PCLK66_SHIFT));

	__raw_writel(reg, S5P_CLK_DIV0);

	do {
		reg = __raw_readl(S5P_CLKDIV_STAT0);
	} while (reg & 0xff);

	/* ARM MCS value changed */
	reg = __raw_readl(S5P_ARM_MCS_CON);
	reg &= ~0x3;
	if (index >= L3)
		reg |= 0x3;
	else
		reg |= 0x1;

	__raw_writel(reg, S5P_ARM_MCS_CON);

	if (pll_changing) {
		/* 5. Set Lock time = 30us*24Mhz = 0x2cf */
		__raw_writel(0x2cf, S5P_APLL_LOCK);

		/*
		 * 6. Turn on APLL
		 * 6-1. Set PMS values
		 * 6-2. Wait untile the PLL is locked
		 */
		if (index == L0)
			__raw_writel(APLL_VAL_1000, S5P_APLL_CON);
		else
			__raw_writel(APLL_VAL_800, S5P_APLL_CON);

		do {
			reg = __raw_readl(S5P_APLL_CON);
		} while (!(reg & (0x1 << 29)));

		/*
		 * 7. Change souce clock from SCLKMPLL(667Mhz)
		 * to SCLKA2M(200Mhz) in MFC_MUX and G3D MUX
		 * (667/4=166)->(200/4=50)Mhz
		 */
		reg = __raw_readl(S5P_CLK_SRC2);
		reg &= ~(S5P_CLKSRC2_G3D_MASK | S5P_CLKSRC2_MFC_MASK);
		reg |= (0 << S5P_CLKSRC2_G3D_SHIFT) |
			(0 << S5P_CLKSRC2_MFC_SHIFT);
		__raw_writel(reg, S5P_CLK_SRC2);

		do {
			reg = __raw_readl(S5P_CLKMUX_STAT1);
		} while (reg & ((1 << 7) | (1 << 3)));

		/*
		 * 8. Change divider for MFC and G3D
		 * (200/4=50)->(200/1=200)Mhz
		 */
		reg = __raw_readl(S5P_CLK_DIV2);
		reg &= ~(S5P_CLKDIV2_G3D_MASK | S5P_CLKDIV2_MFC_MASK);
		reg |= (clkdiv_val[index][10] << S5P_CLKDIV2_G3D_SHIFT) |
			(clkdiv_val[index][9] << S5P_CLKDIV2_MFC_SHIFT);
		__raw_writel(reg, S5P_CLK_DIV2);

		/* For MFC, G3D dividing */
		do {
			reg = __raw_readl(S5P_CLKDIV_STAT0);
		} while (reg & ((1 << 16) | (1 << 17)));

		/* 9. Change MPLL to APLL in MSYS_MUX */
		reg = __raw_readl(S5P_CLK_SRC0);
		reg &= ~(S5P_CLKSRC0_MUX200_MASK);
		reg |= (0x0 << S5P_CLKSRC0_MUX200_SHIFT);
		__raw_writel(reg, S5P_CLK_SRC0);

		do {
			reg = __raw_readl(S5P_CLKMUX_STAT0);
		} while (reg & (0x1 << 18));

		/*
		 * 10. DMC1 refresh counter
		 * L4 : DMC1 = 100Mhz 7.8us/(1/100) = 0x30c
		 * Others : DMC1 = 200Mhz 7.8us/(1/200) = 0x618
		 */
		if (!bus_speed_changing)
			s5pv210_set_refresh(DMC1, 200000);
	}

	/*
	 * L4 level need to change memory bus speed, hence onedram clock divier
	 * and memory refresh parameter should be changed
	 */
	if (bus_speed_changing) {
		reg = __raw_readl(S5P_CLK_DIV6);
		reg &= ~S5P_CLKDIV6_ONEDRAM_MASK;
		reg |= (clkdiv_val[index][8] << S5P_CLKDIV6_ONEDRAM_SHIFT);
		__raw_writel(reg, S5P_CLK_DIV6);

		do {
			reg = __raw_readl(S5P_CLKDIV_STAT1);
		} while (reg & (1 << 15));

		/* Reconfigure DRAM refresh counter value */
		if (index != L4) {
			/*
			 * DMC0 : 166Mhz
			 * DMC1 : 200Mhz
			 */
			s5pv210_set_refresh(DMC0, 166000);
			s5pv210_set_refresh(DMC1, 200000);
		} else {
			/*
			 * DMC0 : 83Mhz
			 * DMC1 : 100Mhz
			 */
			s5pv210_set_refresh(DMC0, 83000);
			s5pv210_set_refresh(DMC1, 100000);
		}
	}

	if (freqs.new < freqs.old) {
		/* Voltage down: will be implemented */
	}

	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	printk(KERN_DEBUG "Perf changed[L%d]\n", index);

	return 0;
}

#ifdef CONFIG_PM
static int s5pv210_cpufreq_suspend(struct cpufreq_policy *policy,
				   pm_message_t pmsg)
{
	return 0;
}

static int s5pv210_cpufreq_resume(struct cpufreq_policy *policy)
{
	return 0;
}
#endif

static int check_mem_type(void __iomem *dmc_reg)
{
	unsigned long val;

	val = __raw_readl(dmc_reg + 0x4);
	val = (val & (0xf << 8));

	return val >> 8;
}

static int __init s5pv210_cpu_init(struct cpufreq_policy *policy)
{
	unsigned long mem_type;

	cpu_clk = clk_get(NULL, "armclk");
	if (IS_ERR(cpu_clk))
		return PTR_ERR(cpu_clk);

	dmc0_clk = clk_get(NULL, "sclk_dmc0");
	if (IS_ERR(dmc0_clk)) {
		clk_put(cpu_clk);
		return PTR_ERR(dmc0_clk);
	}

	dmc1_clk = clk_get(NULL, "hclk_msys");
	if (IS_ERR(dmc1_clk)) {
		clk_put(dmc0_clk);
		clk_put(cpu_clk);
		return PTR_ERR(dmc1_clk);
	}

	if (policy->cpu != 0)
		return -EINVAL;

	/*
	 * check_mem_type : This driver only support LPDDR & LPDDR2.
	 * other memory type is not supported.
	 */
	mem_type = check_mem_type(S5P_VA_DMC0);

	if ((mem_type != LPDDR) && (mem_type != LPDDR2)) {
		printk(KERN_ERR "CPUFreq doesn't support this memory type\n");
		return -EINVAL;
	}

	/* Find current refresh counter and frequency each DMC */
	s5pv210_dram_conf[0].refresh = (__raw_readl(S5P_VA_DMC0 + 0x30) * 1000);
	s5pv210_dram_conf[0].freq = clk_get_rate(dmc0_clk);

	s5pv210_dram_conf[1].refresh = (__raw_readl(S5P_VA_DMC1 + 0x30) * 1000);
	s5pv210_dram_conf[1].freq = clk_get_rate(dmc1_clk);

	policy->cur = policy->min = policy->max = s5pv210_getspeed(0);

	cpufreq_frequency_table_get_attr(s5pv210_freq_table, policy->cpu);

	policy->cpuinfo.transition_latency = 40000;

	return cpufreq_frequency_table_cpuinfo(policy, s5pv210_freq_table);
}

static struct cpufreq_driver s5pv210_driver = {
	.flags		= CPUFREQ_STICKY,
	.verify		= s5pv210_verify_speed,
	.target		= s5pv210_target,
	.get		= s5pv210_getspeed,
	.init		= s5pv210_cpu_init,
	.name		= "s5pv210",
#ifdef CONFIG_PM
	.suspend	= s5pv210_cpufreq_suspend,
	.resume		= s5pv210_cpufreq_resume,
#endif
};

static int __init s5pv210_cpufreq_init(void)
{
	return cpufreq_register_driver(&s5pv210_driver);
}

late_initcall(s5pv210_cpufreq_init);