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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/mach-integrator/cpu.c | |
3 | * | |
4 | * Copyright (C) 2001-2002 Deep Blue Solutions Ltd. | |
5 | * | |
1da177e4 LT |
6 | * This program is free software; you can redistribute it and/or modify |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * CPU support functions | |
11 | */ | |
12 | #include <linux/module.h> | |
13 | #include <linux/types.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/cpufreq.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/sched.h> | |
18 | #include <linux/smp.h> | |
19 | #include <linux/init.h> | |
fced80c7 | 20 | #include <linux/io.h> |
1da177e4 | 21 | |
a09e64fb | 22 | #include <mach/hardware.h> |
a285edcf | 23 | #include <mach/platform.h> |
1da177e4 LT |
24 | #include <asm/mach-types.h> |
25 | #include <asm/hardware/icst525.h> | |
26 | ||
27 | static struct cpufreq_driver integrator_driver; | |
28 | ||
b830b9b5 RK |
29 | #define CM_ID IO_ADDRESS(INTEGRATOR_HDR_ID) |
30 | #define CM_OSC IO_ADDRESS(INTEGRATOR_HDR_OSC) | |
31 | #define CM_STAT IO_ADDRESS(INTEGRATOR_HDR_STAT) | |
32 | #define CM_LOCK IO_ADDRESS(INTEGRATOR_HDR_LOCK) | |
1da177e4 | 33 | |
39c0cb02 | 34 | static const struct icst_params lclk_params = { |
1da177e4 | 35 | .ref = 24000, |
4de2edbd | 36 | .vco_max = ICST525_VCO_MAX_5V, |
1da177e4 LT |
37 | .vd_min = 8, |
38 | .vd_max = 132, | |
39 | .rd_min = 24, | |
40 | .rd_max = 24, | |
41 | }; | |
42 | ||
39c0cb02 | 43 | static const struct icst_params cclk_params = { |
1da177e4 | 44 | .ref = 24000, |
4de2edbd | 45 | .vco_max = ICST525_VCO_MAX_5V, |
1da177e4 LT |
46 | .vd_min = 12, |
47 | .vd_max = 160, | |
48 | .rd_min = 24, | |
49 | .rd_max = 24, | |
50 | }; | |
51 | ||
52 | /* | |
53 | * Validate the speed policy. | |
54 | */ | |
55 | static int integrator_verify_policy(struct cpufreq_policy *policy) | |
56 | { | |
39c0cb02 | 57 | struct icst_vco vco; |
1da177e4 LT |
58 | |
59 | cpufreq_verify_within_limits(policy, | |
60 | policy->cpuinfo.min_freq, | |
61 | policy->cpuinfo.max_freq); | |
62 | ||
63 | vco = icst525_khz_to_vco(&cclk_params, policy->max); | |
64 | policy->max = icst525_khz(&cclk_params, vco); | |
65 | ||
66 | vco = icst525_khz_to_vco(&cclk_params, policy->min); | |
67 | policy->min = icst525_khz(&cclk_params, vco); | |
68 | ||
69 | cpufreq_verify_within_limits(policy, | |
70 | policy->cpuinfo.min_freq, | |
71 | policy->cpuinfo.max_freq); | |
72 | ||
73 | return 0; | |
74 | } | |
75 | ||
76 | ||
77 | static int integrator_set_target(struct cpufreq_policy *policy, | |
78 | unsigned int target_freq, | |
79 | unsigned int relation) | |
80 | { | |
81 | cpumask_t cpus_allowed; | |
82 | int cpu = policy->cpu; | |
39c0cb02 | 83 | struct icst_vco vco; |
1da177e4 LT |
84 | struct cpufreq_freqs freqs; |
85 | u_int cm_osc; | |
86 | ||
87 | /* | |
88 | * Save this threads cpus_allowed mask. | |
89 | */ | |
90 | cpus_allowed = current->cpus_allowed; | |
91 | ||
92 | /* | |
93 | * Bind to the specified CPU. When this call returns, | |
94 | * we should be running on the right CPU. | |
95 | */ | |
96 | set_cpus_allowed(current, cpumask_of_cpu(cpu)); | |
97 | BUG_ON(cpu != smp_processor_id()); | |
98 | ||
99 | /* get current setting */ | |
100 | cm_osc = __raw_readl(CM_OSC); | |
101 | ||
102 | if (machine_is_integrator()) { | |
103 | vco.s = (cm_osc >> 8) & 7; | |
104 | } else if (machine_is_cintegrator()) { | |
105 | vco.s = 1; | |
106 | } | |
107 | vco.v = cm_osc & 255; | |
108 | vco.r = 22; | |
109 | freqs.old = icst525_khz(&cclk_params, vco); | |
110 | ||
111 | /* icst525_khz_to_vco rounds down -- so we need the next | |
112 | * larger freq in case of CPUFREQ_RELATION_L. | |
113 | */ | |
114 | if (relation == CPUFREQ_RELATION_L) | |
115 | target_freq += 999; | |
116 | if (target_freq > policy->max) | |
117 | target_freq = policy->max; | |
118 | vco = icst525_khz_to_vco(&cclk_params, target_freq); | |
119 | freqs.new = icst525_khz(&cclk_params, vco); | |
120 | ||
121 | freqs.cpu = policy->cpu; | |
122 | ||
123 | if (freqs.old == freqs.new) { | |
124 | set_cpus_allowed(current, cpus_allowed); | |
125 | return 0; | |
126 | } | |
127 | ||
128 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
129 | ||
130 | cm_osc = __raw_readl(CM_OSC); | |
131 | ||
132 | if (machine_is_integrator()) { | |
133 | cm_osc &= 0xfffff800; | |
134 | cm_osc |= vco.s << 8; | |
135 | } else if (machine_is_cintegrator()) { | |
136 | cm_osc &= 0xffffff00; | |
137 | } | |
138 | cm_osc |= vco.v; | |
139 | ||
140 | __raw_writel(0xa05f, CM_LOCK); | |
141 | __raw_writel(cm_osc, CM_OSC); | |
142 | __raw_writel(0, CM_LOCK); | |
143 | ||
144 | /* | |
145 | * Restore the CPUs allowed mask. | |
146 | */ | |
147 | set_cpus_allowed(current, cpus_allowed); | |
148 | ||
149 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
150 | ||
151 | return 0; | |
152 | } | |
153 | ||
154 | static unsigned int integrator_get(unsigned int cpu) | |
155 | { | |
156 | cpumask_t cpus_allowed; | |
157 | unsigned int current_freq; | |
158 | u_int cm_osc; | |
39c0cb02 | 159 | struct icst_vco vco; |
1da177e4 LT |
160 | |
161 | cpus_allowed = current->cpus_allowed; | |
162 | ||
163 | set_cpus_allowed(current, cpumask_of_cpu(cpu)); | |
164 | BUG_ON(cpu != smp_processor_id()); | |
165 | ||
166 | /* detect memory etc. */ | |
167 | cm_osc = __raw_readl(CM_OSC); | |
168 | ||
169 | if (machine_is_integrator()) { | |
170 | vco.s = (cm_osc >> 8) & 7; | |
171 | } else if (machine_is_cintegrator()) { | |
172 | vco.s = 1; | |
173 | } | |
174 | vco.v = cm_osc & 255; | |
175 | vco.r = 22; | |
176 | ||
177 | current_freq = icst525_khz(&cclk_params, vco); /* current freq */ | |
178 | ||
179 | set_cpus_allowed(current, cpus_allowed); | |
180 | ||
181 | return current_freq; | |
182 | } | |
183 | ||
184 | static int integrator_cpufreq_init(struct cpufreq_policy *policy) | |
185 | { | |
186 | ||
187 | /* set default policy and cpuinfo */ | |
1da177e4 LT |
188 | policy->cpuinfo.max_freq = 160000; |
189 | policy->cpuinfo.min_freq = 12000; | |
190 | policy->cpuinfo.transition_latency = 1000000; /* 1 ms, assumed */ | |
191 | policy->cur = policy->min = policy->max = integrator_get(policy->cpu); | |
192 | ||
193 | return 0; | |
194 | } | |
195 | ||
196 | static struct cpufreq_driver integrator_driver = { | |
197 | .verify = integrator_verify_policy, | |
198 | .target = integrator_set_target, | |
199 | .get = integrator_get, | |
200 | .init = integrator_cpufreq_init, | |
201 | .name = "integrator", | |
202 | }; | |
203 | ||
204 | static int __init integrator_cpu_init(void) | |
205 | { | |
206 | return cpufreq_register_driver(&integrator_driver); | |
207 | } | |
208 | ||
209 | static void __exit integrator_cpu_exit(void) | |
210 | { | |
211 | cpufreq_unregister_driver(&integrator_driver); | |
212 | } | |
213 | ||
214 | MODULE_AUTHOR ("Russell M. King"); | |
215 | MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs"); | |
216 | MODULE_LICENSE ("GPL"); | |
217 | ||
218 | module_init(integrator_cpu_init); | |
219 | module_exit(integrator_cpu_exit); |