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