exynos5250-cpufreq.c revision bbcf071969b20f356877c8067986be0a2dcaa2aa
1/*
2 * Copyright (c) 2010-20122Samsung Electronics Co., Ltd.
3 *		http://www.samsung.com
4 *
5 * EXYNOS5250 - CPU frequency scaling support
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10*/
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/err.h>
15#include <linux/clk.h>
16#include <linux/io.h>
17#include <linux/slab.h>
18#include <linux/cpufreq.h>
19#include <linux/of.h>
20#include <linux/of_address.h>
21
22#include "exynos-cpufreq.h"
23
24static struct clk *cpu_clk;
25static struct clk *moutcore;
26static struct clk *mout_mpll;
27static struct clk *mout_apll;
28static struct exynos_dvfs_info *cpufreq;
29
30static unsigned int exynos5250_volt_table[] = {
31	1300000, 1250000, 1225000, 1200000, 1150000,
32	1125000, 1100000, 1075000, 1050000, 1025000,
33	1012500, 1000000,  975000,  950000,  937500,
34	925000
35};
36
37static struct cpufreq_frequency_table exynos5250_freq_table[] = {
38	{0, L0, 1700 * 1000},
39	{0, L1, 1600 * 1000},
40	{0, L2, 1500 * 1000},
41	{0, L3, 1400 * 1000},
42	{0, L4, 1300 * 1000},
43	{0, L5, 1200 * 1000},
44	{0, L6, 1100 * 1000},
45	{0, L7, 1000 * 1000},
46	{0, L8,  900 * 1000},
47	{0, L9,  800 * 1000},
48	{0, L10, 700 * 1000},
49	{0, L11, 600 * 1000},
50	{0, L12, 500 * 1000},
51	{0, L13, 400 * 1000},
52	{0, L14, 300 * 1000},
53	{0, L15, 200 * 1000},
54	{0, 0, CPUFREQ_TABLE_END},
55};
56
57static struct apll_freq apll_freq_5250[] = {
58	/*
59	 * values:
60	 * freq
61	 * clock divider for ARM, CPUD, ACP, PERIPH, ATB, PCLK_DBG, APLL, ARM2
62	 * clock divider for COPY, HPM, RESERVED
63	 * PLL M, P, S
64	 */
65	APLL_FREQ(1700, 0, 3, 7, 7, 7, 3, 5, 0, 0, 2, 0, 425, 6, 0),
66	APLL_FREQ(1600, 0, 3, 7, 7, 7, 1, 4, 0, 0, 2, 0, 200, 3, 0),
67	APLL_FREQ(1500, 0, 2, 7, 7, 7, 1, 4, 0, 0, 2, 0, 250, 4, 0),
68	APLL_FREQ(1400, 0, 2, 7, 7, 6, 1, 4, 0, 0, 2, 0, 175, 3, 0),
69	APLL_FREQ(1300, 0, 2, 7, 7, 6, 1, 3, 0, 0, 2, 0, 325, 6, 0),
70	APLL_FREQ(1200, 0, 2, 7, 7, 5, 1, 3, 0, 0, 2, 0, 200, 4, 0),
71	APLL_FREQ(1100, 0, 3, 7, 7, 5, 1, 3, 0, 0, 2, 0, 275, 6, 0),
72	APLL_FREQ(1000, 0, 1, 7, 7, 4, 1, 2, 0, 0, 2, 0, 125, 3, 0),
73	APLL_FREQ(900,  0, 1, 7, 7, 4, 1, 2, 0, 0, 2, 0, 150, 4, 0),
74	APLL_FREQ(800,  0, 1, 7, 7, 4, 1, 2, 0, 0, 2, 0, 100, 3, 0),
75	APLL_FREQ(700,  0, 1, 7, 7, 3, 1, 1, 0, 0, 2, 0, 175, 3, 1),
76	APLL_FREQ(600,  0, 1, 7, 7, 3, 1, 1, 0, 0, 2, 0, 200, 4, 1),
77	APLL_FREQ(500,  0, 1, 7, 7, 2, 1, 1, 0, 0, 2, 0, 125, 3, 1),
78	APLL_FREQ(400,  0, 1, 7, 7, 2, 1, 1, 0, 0, 2, 0, 100, 3, 1),
79	APLL_FREQ(300,  0, 1, 7, 7, 1, 1, 1, 0, 0, 2, 0, 200, 4, 2),
80	APLL_FREQ(200,  0, 1, 7, 7, 1, 1, 1, 0, 0, 2, 0, 100, 3, 2),
81};
82
83static void set_clkdiv(unsigned int div_index)
84{
85	unsigned int tmp;
86
87	/* Change Divider - CPU0 */
88
89	tmp = apll_freq_5250[div_index].clk_div_cpu0;
90
91	__raw_writel(tmp, cpufreq->cmu_regs + EXYNOS5_CLKDIV_CPU0);
92
93	while (__raw_readl(cpufreq->cmu_regs + EXYNOS5_CLKDIV_STATCPU0)
94	       & 0x11111111)
95		cpu_relax();
96
97	/* Change Divider - CPU1 */
98	tmp = apll_freq_5250[div_index].clk_div_cpu1;
99
100	__raw_writel(tmp, cpufreq->cmu_regs + EXYNOS5_CLKDIV_CPU1);
101
102	while (__raw_readl(cpufreq->cmu_regs + EXYNOS5_CLKDIV_STATCPU1) & 0x11)
103		cpu_relax();
104}
105
106static void set_apll(unsigned int index)
107{
108	unsigned int tmp;
109	unsigned int freq = apll_freq_5250[index].freq;
110
111	/* MUX_CORE_SEL = MPLL, ARMCLK uses MPLL for lock time */
112	clk_set_parent(moutcore, mout_mpll);
113
114	do {
115		cpu_relax();
116		tmp = (__raw_readl(cpufreq->cmu_regs + EXYNOS5_CLKMUX_STATCPU)
117			>> 16);
118		tmp &= 0x7;
119	} while (tmp != 0x2);
120
121	clk_set_rate(mout_apll, freq * 1000);
122
123	/* MUX_CORE_SEL = APLL */
124	clk_set_parent(moutcore, mout_apll);
125
126	do {
127		cpu_relax();
128		tmp = __raw_readl(cpufreq->cmu_regs + EXYNOS5_CLKMUX_STATCPU);
129		tmp &= (0x7 << 16);
130	} while (tmp != (0x1 << 16));
131}
132
133static void exynos5250_set_frequency(unsigned int old_index,
134				  unsigned int new_index)
135{
136	if (old_index > new_index) {
137		set_clkdiv(new_index);
138		set_apll(new_index);
139	} else if (old_index < new_index) {
140		set_apll(new_index);
141		set_clkdiv(new_index);
142	}
143}
144
145int exynos5250_cpufreq_init(struct exynos_dvfs_info *info)
146{
147	struct device_node *np;
148	unsigned long rate;
149
150	/*
151	 * HACK: This is a temporary workaround to get access to clock
152	 * controller registers directly and remove static mappings and
153	 * dependencies on platform headers. It is necessary to enable
154	 * Exynos multi-platform support and will be removed together with
155	 * this whole driver as soon as Exynos gets migrated to use
156	 * cpufreq-dt driver.
157	 */
158	np = of_find_compatible_node(NULL, NULL, "samsung,exynos5250-clock");
159	if (!np) {
160		pr_err("%s: failed to find clock controller DT node\n",
161			__func__);
162		return -ENODEV;
163	}
164
165	info->cmu_regs = of_iomap(np, 0);
166	if (!info->cmu_regs) {
167		pr_err("%s: failed to map CMU registers\n", __func__);
168		return -EFAULT;
169	}
170
171	cpu_clk = clk_get(NULL, "armclk");
172	if (IS_ERR(cpu_clk))
173		return PTR_ERR(cpu_clk);
174
175	moutcore = clk_get(NULL, "mout_cpu");
176	if (IS_ERR(moutcore))
177		goto err_moutcore;
178
179	mout_mpll = clk_get(NULL, "mout_mpll");
180	if (IS_ERR(mout_mpll))
181		goto err_mout_mpll;
182
183	rate = clk_get_rate(mout_mpll) / 1000;
184
185	mout_apll = clk_get(NULL, "mout_apll");
186	if (IS_ERR(mout_apll))
187		goto err_mout_apll;
188
189	info->mpll_freq_khz = rate;
190	/* 800Mhz */
191	info->pll_safe_idx = L9;
192	info->cpu_clk = cpu_clk;
193	info->volt_table = exynos5250_volt_table;
194	info->freq_table = exynos5250_freq_table;
195	info->set_freq = exynos5250_set_frequency;
196
197	cpufreq = info;
198
199	return 0;
200
201err_mout_apll:
202	clk_put(mout_mpll);
203err_mout_mpll:
204	clk_put(moutcore);
205err_moutcore:
206	clk_put(cpu_clk);
207
208	pr_err("%s: failed initialization\n", __func__);
209	return -EINVAL;
210}
211