diff options
author | Tony Lindgren <tony@atomide.com> | 2005-07-10 14:58:20 -0400 |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2005-07-10 14:58:20 -0400 |
commit | ec6bced6c7b92904f5ead39c9c1b8dc734e6eff0 (patch) | |
tree | f29a540369cd7c2196b9afd682b1e2943bbb80f7 /arch/arm/plat-omap | |
parent | d3b83419117c8f7fd762b488b67393b94fa94762 (diff) |
[PATCH] ARM: 2803/1: OMAP update 11/11: Add cpufreq support
Patch from Tony Lindgren
This patch adds minimal cpufreq support for OMAP
taking advantage of the clock framework.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/plat-omap')
-rw-r--r-- | arch/arm/plat-omap/Makefile | 1 | ||||
-rw-r--r-- | arch/arm/plat-omap/cpu-omap.c | 128 |
2 files changed, 129 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/Makefile b/arch/arm/plat-omap/Makefile index 3be25ebfc45e..531e11af54d4 100644 --- a/arch/arm/plat-omap/Makefile +++ b/arch/arm/plat-omap/Makefile | |||
@@ -14,3 +14,4 @@ obj-$(CONFIG_ARCH_OMAP16XX) += ocpi.o | |||
14 | # Power Management | 14 | # Power Management |
15 | obj-$(CONFIG_PM) += pm.o sleep.o | 15 | obj-$(CONFIG_PM) += pm.o sleep.o |
16 | 16 | ||
17 | obj-$(CONFIG_CPU_FREQ) += cpu-omap.o | ||
diff --git a/arch/arm/plat-omap/cpu-omap.c b/arch/arm/plat-omap/cpu-omap.c new file mode 100644 index 000000000000..409aac2c4b9d --- /dev/null +++ b/arch/arm/plat-omap/cpu-omap.c | |||
@@ -0,0 +1,128 @@ | |||
1 | /* | ||
2 | * linux/arch/arm/plat-omap/cpu-omap.c | ||
3 | * | ||
4 | * CPU frequency scaling for OMAP | ||
5 | * | ||
6 | * Copyright (C) 2005 Nokia Corporation | ||
7 | * Written by Tony Lindgren <tony@atomide.com> | ||
8 | * | ||
9 | * Based on cpu-sa1110.c, Copyright (C) 2001 Russell King | ||
10 | * | ||
11 | * This program is free software; you can redistribute it and/or modify | ||
12 | * it under the terms of the GNU General Public License version 2 as | ||
13 | * published by the Free Software Foundation. | ||
14 | */ | ||
15 | #include <linux/types.h> | ||
16 | #include <linux/kernel.h> | ||
17 | #include <linux/sched.h> | ||
18 | #include <linux/cpufreq.h> | ||
19 | #include <linux/delay.h> | ||
20 | #include <linux/init.h> | ||
21 | #include <linux/err.h> | ||
22 | |||
23 | #include <asm/hardware.h> | ||
24 | #include <asm/mach-types.h> | ||
25 | #include <asm/io.h> | ||
26 | #include <asm/system.h> | ||
27 | |||
28 | #include <asm/hardware/clock.h> | ||
29 | |||
30 | /* TODO: Add support for SDRAM timing changes */ | ||
31 | |||
32 | int omap_verify_speed(struct cpufreq_policy *policy) | ||
33 | { | ||
34 | struct clk * mpu_clk; | ||
35 | |||
36 | if (policy->cpu) | ||
37 | return -EINVAL; | ||
38 | |||
39 | cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, | ||
40 | policy->cpuinfo.max_freq); | ||
41 | mpu_clk = clk_get(NULL, "mpu"); | ||
42 | if (IS_ERR(mpu_clk)) | ||
43 | return PTR_ERR(mpu_clk); | ||
44 | policy->min = clk_round_rate(mpu_clk, policy->min * 1000) / 1000; | ||
45 | policy->max = clk_round_rate(mpu_clk, policy->max * 1000) / 1000; | ||
46 | cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, | ||
47 | policy->cpuinfo.max_freq); | ||
48 | clk_put(mpu_clk); | ||
49 | |||
50 | return 0; | ||
51 | } | ||
52 | |||
53 | unsigned int omap_getspeed(unsigned int cpu) | ||
54 | { | ||
55 | struct clk * mpu_clk; | ||
56 | unsigned long rate; | ||
57 | |||
58 | if (cpu) | ||
59 | return 0; | ||
60 | |||
61 | mpu_clk = clk_get(NULL, "mpu"); | ||
62 | if (IS_ERR(mpu_clk)) | ||
63 | return 0; | ||
64 | rate = clk_get_rate(mpu_clk) / 1000; | ||
65 | clk_put(mpu_clk); | ||
66 | |||
67 | return rate; | ||
68 | } | ||
69 | |||
70 | static int omap_target(struct cpufreq_policy *policy, | ||
71 | unsigned int target_freq, | ||
72 | unsigned int relation) | ||
73 | { | ||
74 | struct clk * mpu_clk; | ||
75 | struct cpufreq_freqs freqs; | ||
76 | int ret = 0; | ||
77 | |||
78 | mpu_clk = clk_get(NULL, "mpu"); | ||
79 | if (IS_ERR(mpu_clk)) | ||
80 | return PTR_ERR(mpu_clk); | ||
81 | |||
82 | freqs.old = omap_getspeed(0); | ||
83 | freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000; | ||
84 | freqs.cpu = 0; | ||
85 | |||
86 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | ||
87 | ret = clk_set_rate(mpu_clk, target_freq * 1000); | ||
88 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | ||
89 | clk_put(mpu_clk); | ||
90 | |||
91 | return ret; | ||
92 | } | ||
93 | |||
94 | static int __init omap_cpu_init(struct cpufreq_policy *policy) | ||
95 | { | ||
96 | struct clk * mpu_clk; | ||
97 | |||
98 | mpu_clk = clk_get(NULL, "mpu"); | ||
99 | if (IS_ERR(mpu_clk)) | ||
100 | return PTR_ERR(mpu_clk); | ||
101 | |||
102 | if (policy->cpu != 0) | ||
103 | return -EINVAL; | ||
104 | policy->cur = policy->min = policy->max = omap_getspeed(0); | ||
105 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | ||
106 | policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000; | ||
107 | policy->cpuinfo.max_freq = clk_round_rate(mpu_clk, 216000000) / 1000; | ||
108 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; | ||
109 | clk_put(mpu_clk); | ||
110 | |||
111 | return 0; | ||
112 | } | ||
113 | |||
114 | static struct cpufreq_driver omap_driver = { | ||
115 | .flags = CPUFREQ_STICKY, | ||
116 | .verify = omap_verify_speed, | ||
117 | .target = omap_target, | ||
118 | .get = omap_getspeed, | ||
119 | .init = omap_cpu_init, | ||
120 | .name = "omap", | ||
121 | }; | ||
122 | |||
123 | static int __init omap_cpufreq_init(void) | ||
124 | { | ||
125 | return cpufreq_register_driver(&omap_driver); | ||
126 | } | ||
127 | |||
128 | arch_initcall(omap_cpufreq_init); | ||