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>
30 #include <linux/module.h>
31 #include <linux/of_address.h>
33 #include <asm/hw_irq.h>
39 #define SDCASR_REG 0x0100
40 #define SDCASR_REG_STRIDE 0x1000
41 #define SDCPWR_CFGA0_REG 0x0100
42 #define SDCPWR_PWST0_REG 0x0000
43 #define SDCPWR_GIZTIME_REG 0x0440
45 /* SDCPWR_GIZTIME_REG fields */
46 #define SDCPWR_GIZTIME_GR 0x80000000
47 #define SDCPWR_GIZTIME_LONGLOCK 0x000000ff
49 /* Offset of ASR registers from SDC base */
50 #define SDCASR_OFFSET 0x120000
52 static void __iomem *sdcpwr_mapbase;
53 static void __iomem *sdcasr_mapbase;
55 static DEFINE_MUTEX(pas_switch_mutex);
57 /* Current astate, is used when waking up from power savings on
58 * one core, in case the other core has switched states during
61 static int current_astate;
63 /* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */
64 static struct cpufreq_frequency_table pas_freqs[] = {
70 {0, CPUFREQ_TABLE_END},
73 static struct freq_attr *pas_cpu_freqs_attr[] = {
74 &cpufreq_freq_attr_scaling_available_freqs,
79 * hardware specific functions
82 static int get_astate_freq(int astate)
85 ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10));
90 static int get_cur_astate(int cpu)
94 ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG);
95 ret = (ret >> (cpu * 4)) & 0x7;
100 static int get_gizmo_latency(void)
104 giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG);
106 /* just provide the upper bound */
107 if (giztime & SDCPWR_GIZTIME_GR)
108 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000;
110 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000;
115 static void set_astate(int cpu, unsigned int astate)
119 /* Return if called before init has run */
120 if (unlikely(!sdcasr_mapbase))
123 local_irq_save(flags);
125 out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate);
127 local_irq_restore(flags);
130 int check_astate(void)
132 return get_cur_astate(hard_smp_processor_id());
135 void restore_astate(int cpu)
137 set_astate(cpu, current_astate);
144 static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
146 const u32 *max_freqp;
150 struct device_node *cpu, *dn;
153 cpu = of_get_cpu_node(policy->cpu, NULL);
158 dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");
160 dn = of_find_compatible_node(NULL, NULL,
161 "pasemi,pwrficient-sdc");
164 err = of_address_to_resource(dn, 0, &res);
168 sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000);
169 if (!sdcasr_mapbase) {
174 dn = of_find_compatible_node(NULL, NULL, "1682m-gizmo");
176 dn = of_find_compatible_node(NULL, NULL,
177 "pasemi,pwrficient-gizmo");
180 goto out_unmap_sdcasr;
182 err = of_address_to_resource(dn, 0, &res);
185 goto out_unmap_sdcasr;
186 sdcpwr_mapbase = ioremap(res.start, 0x1000);
187 if (!sdcpwr_mapbase) {
189 goto out_unmap_sdcasr;
192 pr_debug("init cpufreq on CPU %d\n", policy->cpu);
194 max_freqp = of_get_property(cpu, "clock-frequency", NULL);
197 goto out_unmap_sdcpwr;
200 /* we need the freq in kHz */
201 max_freq = *max_freqp / 1000;
203 pr_debug("max clock-frequency is at %u kHz\n", max_freq);
204 pr_debug("initializing frequency table\n");
206 /* initialize frequency table */
207 for (i=0; pas_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
208 pas_freqs[i].frequency =
209 get_astate_freq(pas_freqs[i].driver_data) * 100000;
210 pr_debug("%d: %d\n", i, pas_freqs[i].frequency);
213 policy->cpuinfo.transition_latency = get_gizmo_latency();
215 cur_astate = get_cur_astate(policy->cpu);
216 pr_debug("current astate is at %d\n",cur_astate);
218 policy->cur = pas_freqs[cur_astate].frequency;
219 cpumask_copy(policy->cpus, cpu_online_mask);
221 ppc_proc_freq = policy->cur * 1000ul;
223 cpufreq_frequency_table_get_attr(pas_freqs, policy->cpu);
225 /* this ensures that policy->cpuinfo_min and policy->cpuinfo_max
228 return cpufreq_frequency_table_cpuinfo(policy, pas_freqs);
231 iounmap(sdcpwr_mapbase);
234 iounmap(sdcasr_mapbase);
239 static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy)
242 * We don't support CPU hotplug. Don't unmap after the system
243 * has already made it to a running state.
245 if (system_state != SYSTEM_BOOTING)
249 iounmap(sdcasr_mapbase);
251 iounmap(sdcpwr_mapbase);
253 cpufreq_frequency_table_put_attr(policy->cpu);
257 static int pas_cpufreq_verify(struct cpufreq_policy *policy)
259 return cpufreq_frequency_table_verify(policy, pas_freqs);
262 static int pas_cpufreq_target(struct cpufreq_policy *policy,
263 unsigned int target_freq,
264 unsigned int relation)
266 struct cpufreq_freqs freqs;
270 cpufreq_frequency_table_target(policy,
276 freqs.old = policy->cur;
277 freqs.new = pas_freqs[pas_astate_new].frequency;
279 mutex_lock(&pas_switch_mutex);
280 cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
282 pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n",
284 pas_freqs[pas_astate_new].frequency,
285 pas_freqs[pas_astate_new].driver_data);
287 current_astate = pas_astate_new;
289 for_each_online_cpu(i)
290 set_astate(i, pas_astate_new);
292 cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
293 mutex_unlock(&pas_switch_mutex);
295 ppc_proc_freq = freqs.new * 1000ul;
299 static struct cpufreq_driver pas_cpufreq_driver = {
300 .name = "pas-cpufreq",
301 .flags = CPUFREQ_CONST_LOOPS,
302 .init = pas_cpufreq_cpu_init,
303 .exit = pas_cpufreq_cpu_exit,
304 .verify = pas_cpufreq_verify,
305 .target = pas_cpufreq_target,
306 .attr = pas_cpu_freqs_attr,
310 * module init and destoy
313 static int __init pas_cpufreq_init(void)
315 if (!of_machine_is_compatible("PA6T-1682M") &&
316 !of_machine_is_compatible("pasemi,pwrficient"))
319 return cpufreq_register_driver(&pas_cpufreq_driver);
322 static void __exit pas_cpufreq_exit(void)
324 cpufreq_unregister_driver(&pas_cpufreq_driver);
327 module_init(pas_cpufreq_init);
328 module_exit(pas_cpufreq_exit);
330 MODULE_LICENSE("GPL");
331 MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>");