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>
32 #include <asm/hw_irq.h>
38 #define SDCASR_REG 0x0100
39 #define SDCASR_REG_STRIDE 0x1000
40 #define SDCPWR_CFGA0_REG 0x0100
41 #define SDCPWR_PWST0_REG 0x0000
42 #define SDCPWR_GIZTIME_REG 0x0440
44 /* SDCPWR_GIZTIME_REG fields */
45 #define SDCPWR_GIZTIME_GR 0x80000000
46 #define SDCPWR_GIZTIME_LONGLOCK 0x000000ff
48 /* Offset of ASR registers from SDC base */
49 #define SDCASR_OFFSET 0x120000
51 static void __iomem *sdcpwr_mapbase;
52 static void __iomem *sdcasr_mapbase;
54 /* Current astate, is used when waking up from power savings on
55 * one core, in case the other core has switched states during
58 static int current_astate;
60 /* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */
61 static struct cpufreq_frequency_table pas_freqs[] = {
67 {0, CPUFREQ_TABLE_END},
71 * hardware specific functions
74 static int get_astate_freq(int astate)
77 ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10));
82 static int get_cur_astate(int cpu)
86 ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG);
87 ret = (ret >> (cpu * 4)) & 0x7;
92 static int get_gizmo_latency(void)
96 giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG);
98 /* just provide the upper bound */
99 if (giztime & SDCPWR_GIZTIME_GR)
100 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000;
102 ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000;
107 static void set_astate(int cpu, unsigned int astate)
111 /* Return if called before init has run */
112 if (unlikely(!sdcasr_mapbase))
115 local_irq_save(flags);
117 out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate);
119 local_irq_restore(flags);
122 int check_astate(void)
124 return get_cur_astate(hard_smp_processor_id());
127 void restore_astate(int cpu)
129 set_astate(cpu, current_astate);
136 static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
138 const u32 *max_freqp;
142 struct device_node *cpu, *dn;
145 cpu = of_get_cpu_node(policy->cpu, NULL);
150 dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");
152 dn = of_find_compatible_node(NULL, NULL,
153 "pasemi,pwrficient-sdc");
156 err = of_address_to_resource(dn, 0, &res);
160 sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000);
161 if (!sdcasr_mapbase) {
166 dn = of_find_compatible_node(NULL, NULL, "1682m-gizmo");
168 dn = of_find_compatible_node(NULL, NULL,
169 "pasemi,pwrficient-gizmo");
172 goto out_unmap_sdcasr;
174 err = of_address_to_resource(dn, 0, &res);
177 goto out_unmap_sdcasr;
178 sdcpwr_mapbase = ioremap(res.start, 0x1000);
179 if (!sdcpwr_mapbase) {
181 goto out_unmap_sdcasr;
184 pr_debug("init cpufreq on CPU %d\n", policy->cpu);
186 max_freqp = of_get_property(cpu, "clock-frequency", NULL);
189 goto out_unmap_sdcpwr;
192 /* we need the freq in kHz */
193 max_freq = *max_freqp / 1000;
195 pr_debug("max clock-frequency is at %u kHz\n", max_freq);
196 pr_debug("initializing frequency table\n");
198 /* initialize frequency table */
199 for (i=0; pas_freqs[i].frequency!=CPUFREQ_TABLE_END; i++) {
200 pas_freqs[i].frequency =
201 get_astate_freq(pas_freqs[i].driver_data) * 100000;
202 pr_debug("%d: %d\n", i, pas_freqs[i].frequency);
205 cur_astate = get_cur_astate(policy->cpu);
206 pr_debug("current astate is at %d\n",cur_astate);
208 policy->cur = pas_freqs[cur_astate].frequency;
209 ppc_proc_freq = policy->cur * 1000ul;
211 return cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency());
214 iounmap(sdcpwr_mapbase);
217 iounmap(sdcasr_mapbase);
222 static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy)
225 * We don't support CPU hotplug. Don't unmap after the system
226 * has already made it to a running state.
228 if (system_state != SYSTEM_BOOTING)
232 iounmap(sdcasr_mapbase);
234 iounmap(sdcpwr_mapbase);
236 cpufreq_frequency_table_put_attr(policy->cpu);
240 static int pas_cpufreq_target(struct cpufreq_policy *policy,
241 unsigned int pas_astate_new)
245 pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n",
247 pas_freqs[pas_astate_new].frequency,
248 pas_freqs[pas_astate_new].driver_data);
250 current_astate = pas_astate_new;
252 for_each_online_cpu(i)
253 set_astate(i, pas_astate_new);
255 ppc_proc_freq = pas_freqs[pas_astate_new].frequency * 1000ul;
259 static struct cpufreq_driver pas_cpufreq_driver = {
260 .name = "pas-cpufreq",
261 .flags = CPUFREQ_CONST_LOOPS,
262 .init = pas_cpufreq_cpu_init,
263 .exit = pas_cpufreq_cpu_exit,
264 .verify = cpufreq_generic_frequency_table_verify,
265 .target_index = pas_cpufreq_target,
266 .attr = cpufreq_generic_attr,
270 * module init and destoy
273 static int __init pas_cpufreq_init(void)
275 if (!of_machine_is_compatible("PA6T-1682M") &&
276 !of_machine_is_compatible("pasemi,pwrficient"))
279 return cpufreq_register_driver(&pas_cpufreq_driver);
282 static void __exit pas_cpufreq_exit(void)
284 cpufreq_unregister_driver(&pas_cpufreq_driver);
287 module_init(pas_cpufreq_init);
288 module_exit(pas_cpufreq_exit);
290 MODULE_LICENSE("GPL");
291 MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>");