2 * Copyright (C) 2007 PA Semi, Inc
4 * Authors: Egor Martovetsky <egor@pasemi.com>
5 * Olof Johansson <olof@lixom.net>
7 * Maintained by: Olof Johansson <olof@lixom.net>
9 * Based on arch/powerpc/platforms/cell/cbe_cpufreq.c:
10 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
28 #include <linux/cpufreq.h>
29 #include <linux/timer.h>
31 #include <asm/hw_irq.h>
35 #define SDCASR_REG 0x0100
36 #define SDCASR_REG_STRIDE 0x1000
37 #define SDCPWR_CFGA0_REG 0x0100
38 #define SDCPWR_PWST0_REG 0x0000
39 #define SDCPWR_GIZTIME_REG 0x0440
41 /* SDCPWR_GIZTIME_REG fields */
42 #define SDCPWR_GIZTIME_GR 0x80000000
43 #define SDCPWR_GIZTIME_LONGLOCK 0x000000ff
45 /* Offset of ASR registers from SDC base */
46 #define SDCASR_OFFSET 0x120000
48 static void __iomem *sdcpwr_mapbase;
49 static void __iomem *sdcasr_mapbase;
51 static DEFINE_MUTEX(pas_switch_mutex);
53 /* Current astate, is used when waking up from power savings on
54 * one core, in case the other core has switched states during
57 static int current_astate;
59 /* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */
60 static struct cpufreq_frequency_table pas_freqs[] = {
66 {0, CPUFREQ_TABLE_END},
69 static struct freq_attr *pas_cpu_freqs_attr[] = {
70 &cpufreq_freq_attr_scaling_available_freqs,
75 * hardware specific functions
78 static int get_astate_freq(int astate)
81 ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10));
86 static int get_cur_astate(int cpu)
90 ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG);
91 ret = (ret >> (cpu * 4)) & 0x7;
96 static int get_gizmo_latency(void)
100 giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG);
102 /* just provide the upper bound */
103 if (giztime & SDCPWR_GIZTIME_GR)
104 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000;
106 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000;
111 static void set_astate(int cpu, unsigned int astate)
115 /* Return if called before init has run */
116 if (unlikely(!sdcasr_mapbase))
119 local_irq_save(flags);
121 out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate);
123 local_irq_restore(flags);
126 void restore_astate(int cpu)
128 set_astate(cpu, current_astate);
135 static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
140 struct device_node *cpu, *dn;
143 cpu = of_get_cpu_node(policy->cpu, NULL);
148 dn = of_find_compatible_node(NULL, "sdc", "1682m-sdc");
151 err = of_address_to_resource(dn, 0, &res);
155 sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000);
156 if (!sdcasr_mapbase) {
161 dn = of_find_compatible_node(NULL, "gizmo", "1682m-gizmo");
164 goto out_unmap_sdcasr;
166 err = of_address_to_resource(dn, 0, &res);
169 goto out_unmap_sdcasr;
170 sdcpwr_mapbase = ioremap(res.start, 0x1000);
171 if (!sdcpwr_mapbase) {
173 goto out_unmap_sdcasr;
176 pr_debug("init cpufreq on CPU %d\n", policy->cpu);
178 max_freq = (u32*) get_property(cpu, "clock-frequency", NULL);
181 goto out_unmap_sdcpwr;
184 /* we need the freq in kHz */
187 pr_debug("max clock-frequency is at %u kHz\n", *max_freq);
188 pr_debug("initializing frequency table\n");
190 /* initialize frequency table */
191 for (i=0; pas_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
192 pas_freqs[i].frequency = get_astate_freq(pas_freqs[i].index) * 100000;
193 pr_debug("%d: %d\n", i, pas_freqs[i].frequency);
196 policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
198 policy->cpuinfo.transition_latency = get_gizmo_latency();
200 cur_astate = get_cur_astate(policy->cpu);
201 pr_debug("current astate is at %d\n",cur_astate);
203 policy->cur = pas_freqs[cur_astate].frequency;
204 policy->cpus = cpu_online_map;
206 cpufreq_frequency_table_get_attr(pas_freqs, policy->cpu);
208 /* this ensures that policy->cpuinfo_min and policy->cpuinfo_max
211 return cpufreq_frequency_table_cpuinfo(policy, pas_freqs);
214 iounmap(sdcpwr_mapbase);
217 iounmap(sdcasr_mapbase);
222 static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy)
225 iounmap(sdcasr_mapbase);
227 iounmap(sdcpwr_mapbase);
229 cpufreq_frequency_table_put_attr(policy->cpu);
233 static int pas_cpufreq_verify(struct cpufreq_policy *policy)
235 return cpufreq_frequency_table_verify(policy, pas_freqs);
238 static int pas_cpufreq_target(struct cpufreq_policy *policy,
239 unsigned int target_freq,
240 unsigned int relation)
242 struct cpufreq_freqs freqs;
246 cpufreq_frequency_table_target(policy,
252 freqs.old = policy->cur;
253 freqs.new = pas_freqs[pas_astate_new].frequency;
254 freqs.cpu = policy->cpu;
256 mutex_lock(&pas_switch_mutex);
257 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
259 pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n",
261 pas_freqs[pas_astate_new].frequency,
262 pas_freqs[pas_astate_new].index);
264 current_astate = pas_astate_new;
266 for_each_online_cpu(i)
267 set_astate(i, pas_astate_new);
269 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
270 mutex_unlock(&pas_switch_mutex);
275 static struct cpufreq_driver pas_cpufreq_driver = {
276 .name = "pas-cpufreq",
277 .owner = THIS_MODULE,
278 .flags = CPUFREQ_CONST_LOOPS,
279 .init = pas_cpufreq_cpu_init,
280 .exit = pas_cpufreq_cpu_exit,
281 .verify = pas_cpufreq_verify,
282 .target = pas_cpufreq_target,
283 .attr = pas_cpu_freqs_attr,
287 * module init and destoy
290 static int __init pas_cpufreq_init(void)
292 if (!machine_is_compatible("PA6T-1682M"))
295 return cpufreq_register_driver(&pas_cpufreq_driver);
298 static void __exit pas_cpufreq_exit(void)
300 cpufreq_unregister_driver(&pas_cpufreq_driver);
303 module_init(pas_cpufreq_init);
304 module_exit(pas_cpufreq_exit);
306 MODULE_LICENSE("GPL");
307 MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>");