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
 26static 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
 33static 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
 45static 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 */
 60static 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
 82static 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	freqs.cpu = policy->cpu;
127
128	if (freqs.old == freqs.new) {
129		set_cpus_allowed(current, cpus_allowed);
130		return 0;
131	}
132
133	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
134
135	cm_osc = __raw_readl(CM_OSC);
136
137	if (machine_is_integrator()) {
138		cm_osc &= 0xfffff800;
139		cm_osc |= vco.s << 8;
140	} else if (machine_is_cintegrator()) {
141		cm_osc &= 0xffffff00;
142	}
143	cm_osc |= vco.v;
144
145	__raw_writel(0xa05f, CM_LOCK);
146	__raw_writel(cm_osc, CM_OSC);
147	__raw_writel(0, CM_LOCK);
148
149	/*
150	 * Restore the CPUs allowed mask.
151	 */
152	set_cpus_allowed(current, cpus_allowed);
153
154	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
155
156	return 0;
157}
158
159static unsigned int integrator_get(unsigned int cpu)
160{
161	cpumask_t cpus_allowed;
162	unsigned int current_freq;
163	u_int cm_osc;
164	struct icst_vco vco;
165
166	cpus_allowed = current->cpus_allowed;
167
168	set_cpus_allowed(current, cpumask_of_cpu(cpu));
169	BUG_ON(cpu != smp_processor_id());
170
171	/* detect memory etc. */
172	cm_osc = __raw_readl(CM_OSC);
173
174	if (machine_is_integrator()) {
175		vco.s = (cm_osc >> 8) & 7;
176	} else {
177		vco.s = 1;
178	}
179	vco.v = cm_osc & 255;
180	vco.r = 22;
181
182	current_freq = icst_hz(&cclk_params, vco) / 1000; /* current freq */
183
184	set_cpus_allowed(current, cpus_allowed);
185
186	return current_freq;
187}
188
189static int integrator_cpufreq_init(struct cpufreq_policy *policy)
190{
191
192	/* set default policy and cpuinfo */
193	policy->cpuinfo.max_freq = 160000;
194	policy->cpuinfo.min_freq = 12000;
195	policy->cpuinfo.transition_latency = 1000000; /* 1 ms, assumed */
196	policy->cur = policy->min = policy->max = integrator_get(policy->cpu);
197
198	return 0;
199}
200
201static struct cpufreq_driver integrator_driver = {
202	.verify		= integrator_verify_policy,
203	.target		= integrator_set_target,
204	.get		= integrator_get,
205	.init		= integrator_cpufreq_init,
206	.name		= "integrator",
207};
208
209static int __init integrator_cpu_init(void)
210{
211	return cpufreq_register_driver(&integrator_driver);
212}
213
214static void __exit integrator_cpu_exit(void)
215{
216	cpufreq_unregister_driver(&integrator_driver);
217}
218
219MODULE_AUTHOR ("Russell M. King");
220MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs");
221MODULE_LICENSE ("GPL");
222
223module_init(integrator_cpu_init);
224module_exit(integrator_cpu_exit);