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authorBen Dooks <ben-linux@fluff.org>2010-01-25 23:41:30 -0500
committerBen Dooks <ben-linux@fluff.org>2010-02-20 17:33:54 -0500
commitf7be9abaa5f4a64fdcca6808bb7eacb3547e574e (patch)
tree0c14f12dcf4828bcdb8096faf0a577b3cc0c942e /arch/arm/mach-s3c64xx/cpufreq.c
parent88fc68a280709f3fb9488986ab39eac330d17b6d (diff)
ARM: S3C64XX: Move core support to mach-s3c64xx
Move the core S3C64XX support to mach-s3c64xx as it is unlikely to be used outside of this directory. Also move the SoC header files in with it. This includes the clock, cpu, cpufreq, dma, gpiolib and pll support. Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Diffstat (limited to 'arch/arm/mach-s3c64xx/cpufreq.c')
-rw-r--r--arch/arm/mach-s3c64xx/cpufreq.c270
1 files changed, 270 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c64xx/cpufreq.c b/arch/arm/mach-s3c64xx/cpufreq.c
new file mode 100644
index 000000000000..74c0e8347de5
--- /dev/null
+++ b/arch/arm/mach-s3c64xx/cpufreq.c
@@ -0,0 +1,270 @@
1/* linux/arch/arm/plat-s3c64xx/cpufreq.c
2 *
3 * Copyright 2009 Wolfson Microelectronics plc
4 *
5 * S3C64xx CPUfreq 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/kernel.h>
13#include <linux/types.h>
14#include <linux/init.h>
15#include <linux/cpufreq.h>
16#include <linux/clk.h>
17#include <linux/err.h>
18#include <linux/regulator/consumer.h>
19
20static struct clk *armclk;
21static struct regulator *vddarm;
22static unsigned long regulator_latency;
23
24#ifdef CONFIG_CPU_S3C6410
25struct s3c64xx_dvfs {
26 unsigned int vddarm_min;
27 unsigned int vddarm_max;
28};
29
30static struct s3c64xx_dvfs s3c64xx_dvfs_table[] = {
31 [0] = { 1000000, 1150000 },
32 [1] = { 1050000, 1150000 },
33 [2] = { 1100000, 1150000 },
34 [3] = { 1200000, 1350000 },
35};
36
37static struct cpufreq_frequency_table s3c64xx_freq_table[] = {
38 { 0, 66000 },
39 { 0, 133000 },
40 { 1, 222000 },
41 { 1, 266000 },
42 { 2, 333000 },
43 { 2, 400000 },
44 { 2, 532000 },
45 { 2, 533000 },
46 { 3, 667000 },
47 { 0, CPUFREQ_TABLE_END },
48};
49#endif
50
51static int s3c64xx_cpufreq_verify_speed(struct cpufreq_policy *policy)
52{
53 if (policy->cpu != 0)
54 return -EINVAL;
55
56 return cpufreq_frequency_table_verify(policy, s3c64xx_freq_table);
57}
58
59static unsigned int s3c64xx_cpufreq_get_speed(unsigned int cpu)
60{
61 if (cpu != 0)
62 return 0;
63
64 return clk_get_rate(armclk) / 1000;
65}
66
67static int s3c64xx_cpufreq_set_target(struct cpufreq_policy *policy,
68 unsigned int target_freq,
69 unsigned int relation)
70{
71 int ret;
72 unsigned int i;
73 struct cpufreq_freqs freqs;
74 struct s3c64xx_dvfs *dvfs;
75
76 ret = cpufreq_frequency_table_target(policy, s3c64xx_freq_table,
77 target_freq, relation, &i);
78 if (ret != 0)
79 return ret;
80
81 freqs.cpu = 0;
82 freqs.old = clk_get_rate(armclk) / 1000;
83 freqs.new = s3c64xx_freq_table[i].frequency;
84 freqs.flags = 0;
85 dvfs = &s3c64xx_dvfs_table[s3c64xx_freq_table[i].index];
86
87 if (freqs.old == freqs.new)
88 return 0;
89
90 pr_debug("cpufreq: Transition %d-%dkHz\n", freqs.old, freqs.new);
91
92 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
93
94#ifdef CONFIG_REGULATOR
95 if (vddarm && freqs.new > freqs.old) {
96 ret = regulator_set_voltage(vddarm,
97 dvfs->vddarm_min,
98 dvfs->vddarm_max);
99 if (ret != 0) {
100 pr_err("cpufreq: Failed to set VDDARM for %dkHz: %d\n",
101 freqs.new, ret);
102 goto err;
103 }
104 }
105#endif
106
107 ret = clk_set_rate(armclk, freqs.new * 1000);
108 if (ret < 0) {
109 pr_err("cpufreq: Failed to set rate %dkHz: %d\n",
110 freqs.new, ret);
111 goto err;
112 }
113
114#ifdef CONFIG_REGULATOR
115 if (vddarm && freqs.new < freqs.old) {
116 ret = regulator_set_voltage(vddarm,
117 dvfs->vddarm_min,
118 dvfs->vddarm_max);
119 if (ret != 0) {
120 pr_err("cpufreq: Failed to set VDDARM for %dkHz: %d\n",
121 freqs.new, ret);
122 goto err_clk;
123 }
124 }
125#endif
126
127 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
128
129 pr_debug("cpufreq: Set actual frequency %lukHz\n",
130 clk_get_rate(armclk) / 1000);
131
132 return 0;
133
134err_clk:
135 if (clk_set_rate(armclk, freqs.old * 1000) < 0)
136 pr_err("Failed to restore original clock rate\n");
137err:
138 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
139
140 return ret;
141}
142
143#ifdef CONFIG_REGULATOR
144static void __init s3c64xx_cpufreq_config_regulator(void)
145{
146 int count, v, i, found;
147 struct cpufreq_frequency_table *freq;
148 struct s3c64xx_dvfs *dvfs;
149
150 count = regulator_count_voltages(vddarm);
151 if (count < 0) {
152 pr_err("cpufreq: Unable to check supported voltages\n");
153 }
154
155 freq = s3c64xx_freq_table;
156 while (count > 0 && freq->frequency != CPUFREQ_TABLE_END) {
157 if (freq->frequency == CPUFREQ_ENTRY_INVALID)
158 continue;
159
160 dvfs = &s3c64xx_dvfs_table[freq->index];
161 found = 0;
162
163 for (i = 0; i < count; i++) {
164 v = regulator_list_voltage(vddarm, i);
165 if (v >= dvfs->vddarm_min && v <= dvfs->vddarm_max)
166 found = 1;
167 }
168
169 if (!found) {
170 pr_debug("cpufreq: %dkHz unsupported by regulator\n",
171 freq->frequency);
172 freq->frequency = CPUFREQ_ENTRY_INVALID;
173 }
174
175 freq++;
176 }
177
178 /* Guess based on having to do an I2C/SPI write; in future we
179 * will be able to query the regulator performance here. */
180 regulator_latency = 1 * 1000 * 1000;
181}
182#endif
183
184static int __init s3c64xx_cpufreq_driver_init(struct cpufreq_policy *policy)
185{
186 int ret;
187 struct cpufreq_frequency_table *freq;
188
189 if (policy->cpu != 0)
190 return -EINVAL;
191
192 if (s3c64xx_freq_table == NULL) {
193 pr_err("cpufreq: No frequency information for this CPU\n");
194 return -ENODEV;
195 }
196
197 armclk = clk_get(NULL, "armclk");
198 if (IS_ERR(armclk)) {
199 pr_err("cpufreq: Unable to obtain ARMCLK: %ld\n",
200 PTR_ERR(armclk));
201 return PTR_ERR(armclk);
202 }
203
204#ifdef CONFIG_REGULATOR
205 vddarm = regulator_get(NULL, "vddarm");
206 if (IS_ERR(vddarm)) {
207 ret = PTR_ERR(vddarm);
208 pr_err("cpufreq: Failed to obtain VDDARM: %d\n", ret);
209 pr_err("cpufreq: Only frequency scaling available\n");
210 vddarm = NULL;
211 } else {
212 s3c64xx_cpufreq_config_regulator();
213 }
214#endif
215
216 freq = s3c64xx_freq_table;
217 while (freq->frequency != CPUFREQ_TABLE_END) {
218 unsigned long r;
219
220 /* Check for frequencies we can generate */
221 r = clk_round_rate(armclk, freq->frequency * 1000);
222 r /= 1000;
223 if (r != freq->frequency) {
224 pr_debug("cpufreq: %dkHz unsupported by clock\n",
225 freq->frequency);
226 freq->frequency = CPUFREQ_ENTRY_INVALID;
227 }
228
229 /* If we have no regulator then assume startup
230 * frequency is the maximum we can support. */
231 if (!vddarm && freq->frequency > s3c64xx_cpufreq_get_speed(0))
232 freq->frequency = CPUFREQ_ENTRY_INVALID;
233
234 freq++;
235 }
236
237 policy->cur = clk_get_rate(armclk) / 1000;
238
239 /* Datasheet says PLL stabalisation time (if we were to use
240 * the PLLs, which we don't currently) is ~300us worst case,
241 * but add some fudge.
242 */
243 policy->cpuinfo.transition_latency = (500 * 1000) + regulator_latency;
244
245 ret = cpufreq_frequency_table_cpuinfo(policy, s3c64xx_freq_table);
246 if (ret != 0) {
247 pr_err("cpufreq: Failed to configure frequency table: %d\n",
248 ret);
249 regulator_put(vddarm);
250 clk_put(armclk);
251 }
252
253 return ret;
254}
255
256static struct cpufreq_driver s3c64xx_cpufreq_driver = {
257 .owner = THIS_MODULE,
258 .flags = 0,
259 .verify = s3c64xx_cpufreq_verify_speed,
260 .target = s3c64xx_cpufreq_set_target,
261 .get = s3c64xx_cpufreq_get_speed,
262 .init = s3c64xx_cpufreq_driver_init,
263 .name = "s3c",
264};
265
266static int __init s3c64xx_cpufreq_init(void)
267{
268 return cpufreq_register_driver(&s3c64xx_cpufreq_driver);
269}
270module_init(s3c64xx_cpufreq_init);