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7056d423 CC |
1 | /* |
2 | * arch/arm/mach-tegra/cpu-tegra.c | |
3 | * | |
4 | * Copyright (C) 2010 Google, Inc. | |
5 | * | |
6 | * Author: | |
7 | * Colin Cross <ccross@google.com> | |
8 | * Based on arch/arm/plat-omap/cpu-omap.c, (C) 2005 Nokia Corporation | |
9 | * | |
10 | * This software is licensed under the terms of the GNU General Public | |
11 | * License version 2, as published by the Free Software Foundation, and | |
12 | * may be copied, distributed, and modified under those terms. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | */ | |
20 | ||
21 | #include <linux/kernel.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/types.h> | |
24 | #include <linux/sched.h> | |
25 | #include <linux/cpufreq.h> | |
26 | #include <linux/delay.h> | |
27 | #include <linux/init.h> | |
28 | #include <linux/err.h> | |
29 | #include <linux/clk.h> | |
30 | #include <linux/io.h> | |
31 | ||
32 | #include <asm/system.h> | |
33 | ||
34 | #include <mach/hardware.h> | |
35 | #include <mach/clk.h> | |
36 | ||
37 | /* Frequency table index must be sequential starting at 0 */ | |
38 | static struct cpufreq_frequency_table freq_table[] = { | |
39 | { 0, 312000 }, | |
40 | { 1, 456000 }, | |
41 | { 2, 608000 }, | |
42 | { 3, 760000 }, | |
43 | { 4, 816000 }, | |
44 | { 5, 912000 }, | |
45 | { 6, 1000000 }, | |
46 | { 7, CPUFREQ_TABLE_END }, | |
47 | }; | |
48 | ||
49 | #define NUM_CPUS 2 | |
50 | ||
51 | static struct clk *cpu_clk; | |
52 | ||
53 | static unsigned long target_cpu_speed[NUM_CPUS]; | |
54 | ||
55 | int tegra_verify_speed(struct cpufreq_policy *policy) | |
56 | { | |
57 | return cpufreq_frequency_table_verify(policy, freq_table); | |
58 | } | |
59 | ||
60 | unsigned int tegra_getspeed(unsigned int cpu) | |
61 | { | |
62 | unsigned long rate; | |
63 | ||
64 | if (cpu >= NUM_CPUS) | |
65 | return 0; | |
66 | ||
67 | rate = clk_get_rate(cpu_clk) / 1000; | |
68 | return rate; | |
69 | } | |
70 | ||
71 | static int tegra_update_cpu_speed(void) | |
72 | { | |
73 | int i; | |
74 | unsigned long rate = 0; | |
75 | int ret = 0; | |
76 | struct cpufreq_freqs freqs; | |
77 | ||
78 | for_each_online_cpu(i) | |
79 | rate = max(rate, target_cpu_speed[i]); | |
80 | ||
81 | freqs.old = tegra_getspeed(0); | |
82 | freqs.new = rate; | |
83 | ||
84 | if (freqs.old == freqs.new) | |
85 | return ret; | |
86 | ||
87 | for_each_online_cpu(freqs.cpu) | |
88 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
89 | ||
90 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
91 | printk(KERN_DEBUG "cpufreq-tegra: transition: %u --> %u\n", | |
92 | freqs.old, freqs.new); | |
93 | #endif | |
94 | ||
95 | ret = clk_set_rate_cansleep(cpu_clk, freqs.new * 1000); | |
96 | if (ret) { | |
97 | pr_err("cpu-tegra: Failed to set cpu frequency to %d kHz\n", | |
98 | freqs.new); | |
99 | return ret; | |
100 | } | |
101 | ||
102 | for_each_online_cpu(freqs.cpu) | |
103 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
104 | ||
105 | return 0; | |
106 | } | |
107 | ||
108 | static int tegra_target(struct cpufreq_policy *policy, | |
109 | unsigned int target_freq, | |
110 | unsigned int relation) | |
111 | { | |
112 | int idx; | |
113 | unsigned int freq; | |
114 | ||
115 | cpufreq_frequency_table_target(policy, freq_table, target_freq, | |
116 | relation, &idx); | |
117 | ||
118 | freq = freq_table[idx].frequency; | |
119 | ||
120 | target_cpu_speed[policy->cpu] = freq; | |
121 | ||
122 | return tegra_update_cpu_speed(); | |
123 | } | |
124 | ||
125 | static int tegra_cpu_init(struct cpufreq_policy *policy) | |
126 | { | |
127 | if (policy->cpu >= NUM_CPUS) | |
128 | return -EINVAL; | |
129 | ||
130 | cpu_clk = clk_get_sys(NULL, "cpu"); | |
131 | if (IS_ERR(cpu_clk)) | |
132 | return PTR_ERR(cpu_clk); | |
133 | ||
134 | cpufreq_frequency_table_cpuinfo(policy, freq_table); | |
135 | cpufreq_frequency_table_get_attr(freq_table, policy->cpu); | |
136 | policy->cur = tegra_getspeed(policy->cpu); | |
137 | target_cpu_speed[policy->cpu] = policy->cur; | |
138 | ||
139 | /* FIXME: what's the actual transition time? */ | |
140 | policy->cpuinfo.transition_latency = 300 * 1000; | |
141 | ||
142 | policy->shared_type = CPUFREQ_SHARED_TYPE_ALL; | |
143 | cpumask_copy(policy->related_cpus, cpu_possible_mask); | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | static int tegra_cpu_exit(struct cpufreq_policy *policy) | |
149 | { | |
150 | cpufreq_frequency_table_cpuinfo(policy, freq_table); | |
151 | clk_put(cpu_clk); | |
152 | return 0; | |
153 | } | |
154 | ||
155 | static struct freq_attr *tegra_cpufreq_attr[] = { | |
156 | &cpufreq_freq_attr_scaling_available_freqs, | |
157 | NULL, | |
158 | }; | |
159 | ||
160 | static struct cpufreq_driver tegra_cpufreq_driver = { | |
161 | .verify = tegra_verify_speed, | |
162 | .target = tegra_target, | |
163 | .get = tegra_getspeed, | |
164 | .init = tegra_cpu_init, | |
165 | .exit = tegra_cpu_exit, | |
166 | .name = "tegra", | |
167 | .attr = tegra_cpufreq_attr, | |
168 | }; | |
169 | ||
170 | static int __init tegra_cpufreq_init(void) | |
171 | { | |
172 | return cpufreq_register_driver(&tegra_cpufreq_driver); | |
173 | } | |
174 | ||
175 | static void __exit tegra_cpufreq_exit(void) | |
176 | { | |
177 | cpufreq_unregister_driver(&tegra_cpufreq_driver); | |
178 | } | |
179 | ||
180 | ||
181 | MODULE_AUTHOR("Colin Cross <ccross@android.com>"); | |
182 | MODULE_DESCRIPTION("cpufreq driver for Nvidia Tegra2"); | |
183 | MODULE_LICENSE("GPL"); | |
184 | module_init(tegra_cpufreq_init); | |
185 | module_exit(tegra_cpufreq_exit); |