Merge branch 'for-rmk' of git://git.marvell.com/orion
[linux-2.6] / arch / arm / mach-integrator / cpu.c
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  */
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
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
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
183 static int integrator_cpufreq_init(struct cpufreq_policy *policy)
184 {
185
186         /* set default policy and cpuinfo */
187         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
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);