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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 | * 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/sched.h> | |
17 | #include <linux/smp.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/io.h> | |
20 | ||
21 | #include <mach/hardware.h> | |
22 | #include <mach/platform.h> | |
23 | #include <asm/mach-types.h> | |
24 | #include <asm/hardware/icst.h> | |
25 | ||
26 | static struct cpufreq_driver integrator_driver; | |
27 | ||
28 | #define CM_ID __io_address(INTEGRATOR_HDR_ID) | |
29 | #define CM_OSC __io_address(INTEGRATOR_HDR_OSC) | |
30 | #define CM_STAT __io_address(INTEGRATOR_HDR_STAT) | |
31 | #define CM_LOCK __io_address(INTEGRATOR_HDR_LOCK) | |
32 | ||
33 | static const struct icst_params lclk_params = { | |
34 | .ref = 24000000, | |
35 | .vco_max = ICST525_VCO_MAX_5V, | |
36 | .vco_min = ICST525_VCO_MIN, | |
37 | .vd_min = 8, | |
38 | .vd_max = 132, | |
39 | .rd_min = 24, | |
40 | .rd_max = 24, | |
41 | .s2div = icst525_s2div, | |
42 | .idx2s = icst525_idx2s, | |
43 | }; | |
44 | ||
45 | static const struct icst_params cclk_params = { | |
46 | .ref = 24000000, | |
47 | .vco_max = ICST525_VCO_MAX_5V, | |
48 | .vco_min = ICST525_VCO_MIN, | |
49 | .vd_min = 12, | |
50 | .vd_max = 160, | |
51 | .rd_min = 24, | |
52 | .rd_max = 24, | |
53 | .s2div = icst525_s2div, | |
54 | .idx2s = icst525_idx2s, | |
55 | }; | |
56 | ||
57 | /* | |
58 | * Validate the speed policy. | |
59 | */ | |
60 | static int integrator_verify_policy(struct cpufreq_policy *policy) | |
61 | { | |
62 | struct icst_vco vco; | |
63 | ||
64 | cpufreq_verify_within_limits(policy, | |
65 | policy->cpuinfo.min_freq, | |
66 | policy->cpuinfo.max_freq); | |
67 | ||
68 | vco = icst_hz_to_vco(&cclk_params, policy->max * 1000); | |
69 | policy->max = icst_hz(&cclk_params, vco) / 1000; | |
70 | ||
71 | vco = icst_hz_to_vco(&cclk_params, policy->min * 1000); | |
72 | policy->min = icst_hz(&cclk_params, vco) / 1000; | |
73 | ||
74 | cpufreq_verify_within_limits(policy, | |
75 | policy->cpuinfo.min_freq, | |
76 | policy->cpuinfo.max_freq); | |
77 | ||
78 | return 0; | |
79 | } | |
80 | ||
81 | ||
82 | static int integrator_set_target(struct cpufreq_policy *policy, | |
83 | unsigned int target_freq, | |
84 | unsigned int relation) | |
85 | { | |
86 | cpumask_t cpus_allowed; | |
87 | int cpu = policy->cpu; | |
88 | struct icst_vco vco; | |
89 | struct cpufreq_freqs freqs; | |
90 | u_int cm_osc; | |
91 | ||
92 | /* | |
93 | * Save this threads cpus_allowed mask. | |
94 | */ | |
95 | cpus_allowed = current->cpus_allowed; | |
96 | ||
97 | /* | |
98 | * Bind to the specified CPU. When this call returns, | |
99 | * we should be running on the right CPU. | |
100 | */ | |
101 | set_cpus_allowed(current, cpumask_of_cpu(cpu)); | |
102 | BUG_ON(cpu != smp_processor_id()); | |
103 | ||
104 | /* get current setting */ | |
105 | cm_osc = __raw_readl(CM_OSC); | |
106 | ||
107 | if (machine_is_integrator()) { | |
108 | vco.s = (cm_osc >> 8) & 7; | |
109 | } else if (machine_is_cintegrator()) { | |
110 | vco.s = 1; | |
111 | } | |
112 | vco.v = cm_osc & 255; | |
113 | vco.r = 22; | |
114 | freqs.old = icst_hz(&cclk_params, vco) / 1000; | |
115 | ||
116 | /* icst_hz_to_vco rounds down -- so we need the next | |
117 | * larger freq in case of CPUFREQ_RELATION_L. | |
118 | */ | |
119 | if (relation == CPUFREQ_RELATION_L) | |
120 | target_freq += 999; | |
121 | if (target_freq > policy->max) | |
122 | target_freq = policy->max; | |
123 | vco = icst_hz_to_vco(&cclk_params, target_freq * 1000); | |
124 | freqs.new = icst_hz(&cclk_params, vco) / 1000; | |
125 | ||
126 | if (freqs.old == freqs.new) { | |
127 | set_cpus_allowed(current, cpus_allowed); | |
128 | return 0; | |
129 | } | |
130 | ||
131 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
132 | ||
133 | cm_osc = __raw_readl(CM_OSC); | |
134 | ||
135 | if (machine_is_integrator()) { | |
136 | cm_osc &= 0xfffff800; | |
137 | cm_osc |= vco.s << 8; | |
138 | } else if (machine_is_cintegrator()) { | |
139 | cm_osc &= 0xffffff00; | |
140 | } | |
141 | cm_osc |= vco.v; | |
142 | ||
143 | __raw_writel(0xa05f, CM_LOCK); | |
144 | __raw_writel(cm_osc, CM_OSC); | |
145 | __raw_writel(0, CM_LOCK); | |
146 | ||
147 | /* | |
148 | * Restore the CPUs allowed mask. | |
149 | */ | |
150 | set_cpus_allowed(current, cpus_allowed); | |
151 | ||
152 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
153 | ||
154 | return 0; | |
155 | } | |
156 | ||
157 | static unsigned int integrator_get(unsigned int cpu) | |
158 | { | |
159 | cpumask_t cpus_allowed; | |
160 | unsigned int current_freq; | |
161 | u_int cm_osc; | |
162 | struct icst_vco vco; | |
163 | ||
164 | cpus_allowed = current->cpus_allowed; | |
165 | ||
166 | set_cpus_allowed(current, cpumask_of_cpu(cpu)); | |
167 | BUG_ON(cpu != smp_processor_id()); | |
168 | ||
169 | /* detect memory etc. */ | |
170 | cm_osc = __raw_readl(CM_OSC); | |
171 | ||
172 | if (machine_is_integrator()) { | |
173 | vco.s = (cm_osc >> 8) & 7; | |
174 | } else { | |
175 | vco.s = 1; | |
176 | } | |
177 | vco.v = cm_osc & 255; | |
178 | vco.r = 22; | |
179 | ||
180 | current_freq = icst_hz(&cclk_params, vco) / 1000; /* current freq */ | |
181 | ||
182 | set_cpus_allowed(current, cpus_allowed); | |
183 | ||
184 | return current_freq; | |
185 | } | |
186 | ||
187 | static int integrator_cpufreq_init(struct cpufreq_policy *policy) | |
188 | { | |
189 | ||
190 | /* set default policy and cpuinfo */ | |
191 | policy->cpuinfo.max_freq = 160000; | |
192 | policy->cpuinfo.min_freq = 12000; | |
193 | policy->cpuinfo.transition_latency = 1000000; /* 1 ms, assumed */ | |
194 | policy->cur = policy->min = policy->max = integrator_get(policy->cpu); | |
195 | ||
196 | return 0; | |
197 | } | |
198 | ||
199 | static struct cpufreq_driver integrator_driver = { | |
200 | .verify = integrator_verify_policy, | |
201 | .target = integrator_set_target, | |
202 | .get = integrator_get, | |
203 | .init = integrator_cpufreq_init, | |
204 | .name = "integrator", | |
205 | }; | |
206 | ||
207 | static int __init integrator_cpu_init(void) | |
208 | { | |
209 | return cpufreq_register_driver(&integrator_driver); | |
210 | } | |
211 | ||
212 | static void __exit integrator_cpu_exit(void) | |
213 | { | |
214 | cpufreq_unregister_driver(&integrator_driver); | |
215 | } | |
216 | ||
217 | MODULE_AUTHOR ("Russell M. King"); | |
218 | MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs"); | |
219 | MODULE_LICENSE ("GPL"); | |
220 | ||
221 | module_init(integrator_cpu_init); | |
222 | module_exit(integrator_cpu_exit); |