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1 | /* |
2 | * linux/arch/arm/mach-integrator/cpu.c | |
3 | * | |
4 | * Copyright (C) 2001-2002 Deep Blue Solutions Ltd. | |
5 | * | |
6 | * $Id: cpu.c,v 1.6 2002/07/18 13:58:51 rmk Exp $ | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | * | |
12 | * CPU support functions | |
13 | */ | |
14 | #include <linux/module.h> | |
15 | #include <linux/types.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/cpufreq.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/sched.h> | |
20 | #include <linux/smp.h> | |
21 | #include <linux/init.h> | |
22 | ||
23 | #include <asm/hardware.h> | |
24 | #include <asm/io.h> | |
25 | #include <asm/mach-types.h> | |
26 | #include <asm/hardware/icst525.h> | |
27 | ||
28 | static struct cpufreq_driver integrator_driver; | |
29 | ||
30 | #define CM_ID (IO_ADDRESS(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_ID_OFFSET) | |
31 | #define CM_OSC (IO_ADDRESS(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_OSC_OFFSET) | |
32 | #define CM_STAT (IO_ADDRESS(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_STAT_OFFSET) | |
33 | #define CM_LOCK (IO_ADDRESS(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_LOCK_OFFSET) | |
34 | ||
35 | static const struct icst525_params lclk_params = { | |
36 | .ref = 24000, | |
37 | .vco_max = 320000, | |
38 | .vd_min = 8, | |
39 | .vd_max = 132, | |
40 | .rd_min = 24, | |
41 | .rd_max = 24, | |
42 | }; | |
43 | ||
44 | static const struct icst525_params cclk_params = { | |
45 | .ref = 24000, | |
46 | .vco_max = 320000, | |
47 | .vd_min = 12, | |
48 | .vd_max = 160, | |
49 | .rd_min = 24, | |
50 | .rd_max = 24, | |
51 | }; | |
52 | ||
53 | /* | |
54 | * Validate the speed policy. | |
55 | */ | |
56 | static int integrator_verify_policy(struct cpufreq_policy *policy) | |
57 | { | |
58 | struct icst525_vco vco; | |
59 | ||
60 | cpufreq_verify_within_limits(policy, | |
61 | policy->cpuinfo.min_freq, | |
62 | policy->cpuinfo.max_freq); | |
63 | ||
64 | vco = icst525_khz_to_vco(&cclk_params, policy->max); | |
65 | policy->max = icst525_khz(&cclk_params, vco); | |
66 | ||
67 | vco = icst525_khz_to_vco(&cclk_params, policy->min); | |
68 | policy->min = icst525_khz(&cclk_params, vco); | |
69 | ||
70 | cpufreq_verify_within_limits(policy, | |
71 | policy->cpuinfo.min_freq, | |
72 | policy->cpuinfo.max_freq); | |
73 | ||
74 | return 0; | |
75 | } | |
76 | ||
77 | ||
78 | static int integrator_set_target(struct cpufreq_policy *policy, | |
79 | unsigned int target_freq, | |
80 | unsigned int relation) | |
81 | { | |
82 | cpumask_t cpus_allowed; | |
83 | int cpu = policy->cpu; | |
84 | struct icst525_vco vco; | |
85 | struct cpufreq_freqs freqs; | |
86 | u_int cm_osc; | |
87 | ||
88 | /* | |
89 | * Save this threads cpus_allowed mask. | |
90 | */ | |
91 | cpus_allowed = current->cpus_allowed; | |
92 | ||
93 | /* | |
94 | * Bind to the specified CPU. When this call returns, | |
95 | * we should be running on the right CPU. | |
96 | */ | |
97 | set_cpus_allowed(current, cpumask_of_cpu(cpu)); | |
98 | BUG_ON(cpu != smp_processor_id()); | |
99 | ||
100 | /* get current setting */ | |
101 | cm_osc = __raw_readl(CM_OSC); | |
102 | ||
103 | if (machine_is_integrator()) { | |
104 | vco.s = (cm_osc >> 8) & 7; | |
105 | } else if (machine_is_cintegrator()) { | |
106 | vco.s = 1; | |
107 | } | |
108 | vco.v = cm_osc & 255; | |
109 | vco.r = 22; | |
110 | freqs.old = icst525_khz(&cclk_params, vco); | |
111 | ||
112 | /* icst525_khz_to_vco rounds down -- so we need the next | |
113 | * larger freq in case of CPUFREQ_RELATION_L. | |
114 | */ | |
115 | if (relation == CPUFREQ_RELATION_L) | |
116 | target_freq += 999; | |
117 | if (target_freq > policy->max) | |
118 | target_freq = policy->max; | |
119 | vco = icst525_khz_to_vco(&cclk_params, target_freq); | |
120 | freqs.new = icst525_khz(&cclk_params, vco); | |
121 | ||
122 | freqs.cpu = policy->cpu; | |
123 | ||
124 | if (freqs.old == freqs.new) { | |
125 | set_cpus_allowed(current, cpus_allowed); | |
126 | return 0; | |
127 | } | |
128 | ||
129 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
130 | ||
131 | cm_osc = __raw_readl(CM_OSC); | |
132 | ||
133 | if (machine_is_integrator()) { | |
134 | cm_osc &= 0xfffff800; | |
135 | cm_osc |= vco.s << 8; | |
136 | } else if (machine_is_cintegrator()) { | |
137 | cm_osc &= 0xffffff00; | |
138 | } | |
139 | cm_osc |= vco.v; | |
140 | ||
141 | __raw_writel(0xa05f, CM_LOCK); | |
142 | __raw_writel(cm_osc, CM_OSC); | |
143 | __raw_writel(0, CM_LOCK); | |
144 | ||
145 | /* | |
146 | * Restore the CPUs allowed mask. | |
147 | */ | |
148 | set_cpus_allowed(current, cpus_allowed); | |
149 | ||
150 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
151 | ||
152 | return 0; | |
153 | } | |
154 | ||
155 | static unsigned int integrator_get(unsigned int cpu) | |
156 | { | |
157 | cpumask_t cpus_allowed; | |
158 | unsigned int current_freq; | |
159 | u_int cm_osc; | |
160 | struct icst525_vco vco; | |
161 | ||
162 | cpus_allowed = current->cpus_allowed; | |
163 | ||
164 | set_cpus_allowed(current, cpumask_of_cpu(cpu)); | |
165 | BUG_ON(cpu != smp_processor_id()); | |
166 | ||
167 | /* detect memory etc. */ | |
168 | cm_osc = __raw_readl(CM_OSC); | |
169 | ||
170 | if (machine_is_integrator()) { | |
171 | vco.s = (cm_osc >> 8) & 7; | |
172 | } else if (machine_is_cintegrator()) { | |
173 | vco.s = 1; | |
174 | } | |
175 | vco.v = cm_osc & 255; | |
176 | vco.r = 22; | |
177 | ||
178 | current_freq = icst525_khz(&cclk_params, vco); /* current freq */ | |
179 | ||
180 | set_cpus_allowed(current, cpus_allowed); | |
181 | ||
182 | return current_freq; | |
183 | } | |
184 | ||
185 | static int integrator_cpufreq_init(struct cpufreq_policy *policy) | |
186 | { | |
187 | ||
188 | /* set default policy and cpuinfo */ | |
189 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
190 | policy->cpuinfo.max_freq = 160000; | |
191 | policy->cpuinfo.min_freq = 12000; | |
192 | policy->cpuinfo.transition_latency = 1000000; /* 1 ms, assumed */ | |
193 | policy->cur = policy->min = policy->max = integrator_get(policy->cpu); | |
194 | ||
195 | return 0; | |
196 | } | |
197 | ||
198 | static struct cpufreq_driver integrator_driver = { | |
199 | .verify = integrator_verify_policy, | |
200 | .target = integrator_set_target, | |
201 | .get = integrator_get, | |
202 | .init = integrator_cpufreq_init, | |
203 | .name = "integrator", | |
204 | }; | |
205 | ||
206 | static int __init integrator_cpu_init(void) | |
207 | { | |
208 | return cpufreq_register_driver(&integrator_driver); | |
209 | } | |
210 | ||
211 | static void __exit integrator_cpu_exit(void) | |
212 | { | |
213 | cpufreq_unregister_driver(&integrator_driver); | |
214 | } | |
215 | ||
216 | MODULE_AUTHOR ("Russell M. King"); | |
217 | MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs"); | |
218 | MODULE_LICENSE ("GPL"); | |
219 | ||
220 | module_init(integrator_cpu_init); | |
221 | module_exit(integrator_cpu_exit); |