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 static DEFINE_MUTEX(pas_switch_mutex
);
56 /* Current astate, is used when waking up from power savings on
57 * one core, in case the other core has switched states during
60 static int current_astate
;
62 /* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */
63 static struct cpufreq_frequency_table pas_freqs
[] = {
69 {0, CPUFREQ_TABLE_END
},
72 static struct freq_attr
*pas_cpu_freqs_attr
[] = {
73 &cpufreq_freq_attr_scaling_available_freqs
,
78 * hardware specific functions
81 static int get_astate_freq(int astate
)
84 ret
= in_le32(sdcpwr_mapbase
+ SDCPWR_CFGA0_REG
+ (astate
* 0x10));
89 static int get_cur_astate(int cpu
)
93 ret
= in_le32(sdcpwr_mapbase
+ SDCPWR_PWST0_REG
);
94 ret
= (ret
>> (cpu
* 4)) & 0x7;
99 static int get_gizmo_latency(void)
103 giztime
= in_le32(sdcpwr_mapbase
+ SDCPWR_GIZTIME_REG
);
105 /* just provide the upper bound */
106 if (giztime
& SDCPWR_GIZTIME_GR
)
107 ret
= (giztime
& SDCPWR_GIZTIME_LONGLOCK
) * 128000;
109 ret
= (giztime
& SDCPWR_GIZTIME_LONGLOCK
) * 1000;
114 static void set_astate(int cpu
, unsigned int astate
)
118 /* Return if called before init has run */
119 if (unlikely(!sdcasr_mapbase
))
122 local_irq_save(flags
);
124 out_le32(sdcasr_mapbase
+ SDCASR_REG
+ SDCASR_REG_STRIDE
*cpu
, astate
);
126 local_irq_restore(flags
);
129 int check_astate(void)
131 return get_cur_astate(hard_smp_processor_id());
134 void restore_astate(int cpu
)
136 set_astate(cpu
, current_astate
);
143 static int pas_cpufreq_cpu_init(struct cpufreq_policy
*policy
)
145 const u32
*max_freqp
;
149 struct device_node
*cpu
, *dn
;
152 cpu
= of_get_cpu_node(policy
->cpu
, NULL
);
157 dn
= of_find_compatible_node(NULL
, NULL
, "1682m-sdc");
159 dn
= of_find_compatible_node(NULL
, NULL
,
160 "pasemi,pwrficient-sdc");
163 err
= of_address_to_resource(dn
, 0, &res
);
167 sdcasr_mapbase
= ioremap(res
.start
+ SDCASR_OFFSET
, 0x2000);
168 if (!sdcasr_mapbase
) {
173 dn
= of_find_compatible_node(NULL
, NULL
, "1682m-gizmo");
175 dn
= of_find_compatible_node(NULL
, NULL
,
176 "pasemi,pwrficient-gizmo");
179 goto out_unmap_sdcasr
;
181 err
= of_address_to_resource(dn
, 0, &res
);
184 goto out_unmap_sdcasr
;
185 sdcpwr_mapbase
= ioremap(res
.start
, 0x1000);
186 if (!sdcpwr_mapbase
) {
188 goto out_unmap_sdcasr
;
191 pr_debug("init cpufreq on CPU %d\n", policy
->cpu
);
193 max_freqp
= of_get_property(cpu
, "clock-frequency", NULL
);
196 goto out_unmap_sdcpwr
;
199 /* we need the freq in kHz */
200 max_freq
= *max_freqp
/ 1000;
202 pr_debug("max clock-frequency is at %u kHz\n", max_freq
);
203 pr_debug("initializing frequency table\n");
205 /* initialize frequency table */
206 for (i
=0; pas_freqs
[i
].frequency
!=CPUFREQ_TABLE_END
; i
++) {
207 pas_freqs
[i
].frequency
=
208 get_astate_freq(pas_freqs
[i
].driver_data
) * 100000;
209 pr_debug("%d: %d\n", i
, pas_freqs
[i
].frequency
);
212 policy
->cpuinfo
.transition_latency
= get_gizmo_latency();
214 cur_astate
= get_cur_astate(policy
->cpu
);
215 pr_debug("current astate is at %d\n",cur_astate
);
217 policy
->cur
= pas_freqs
[cur_astate
].frequency
;
218 cpumask_copy(policy
->cpus
, cpu_online_mask
);
220 ppc_proc_freq
= policy
->cur
* 1000ul;
222 cpufreq_frequency_table_get_attr(pas_freqs
, policy
->cpu
);
224 /* this ensures that policy->cpuinfo_min and policy->cpuinfo_max
227 return cpufreq_frequency_table_cpuinfo(policy
, pas_freqs
);
230 iounmap(sdcpwr_mapbase
);
233 iounmap(sdcasr_mapbase
);
238 static int pas_cpufreq_cpu_exit(struct cpufreq_policy
*policy
)
241 * We don't support CPU hotplug. Don't unmap after the system
242 * has already made it to a running state.
244 if (system_state
!= SYSTEM_BOOTING
)
248 iounmap(sdcasr_mapbase
);
250 iounmap(sdcpwr_mapbase
);
252 cpufreq_frequency_table_put_attr(policy
->cpu
);
256 static int pas_cpufreq_verify(struct cpufreq_policy
*policy
)
258 return cpufreq_frequency_table_verify(policy
, pas_freqs
);
261 static int pas_cpufreq_target(struct cpufreq_policy
*policy
,
262 unsigned int target_freq
,
263 unsigned int relation
)
265 struct cpufreq_freqs freqs
;
269 cpufreq_frequency_table_target(policy
,
275 freqs
.old
= policy
->cur
;
276 freqs
.new = pas_freqs
[pas_astate_new
].frequency
;
278 mutex_lock(&pas_switch_mutex
);
279 cpufreq_notify_transition(policy
, &freqs
, CPUFREQ_PRECHANGE
);
281 pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n",
283 pas_freqs
[pas_astate_new
].frequency
,
284 pas_freqs
[pas_astate_new
].driver_data
);
286 current_astate
= pas_astate_new
;
288 for_each_online_cpu(i
)
289 set_astate(i
, pas_astate_new
);
291 cpufreq_notify_transition(policy
, &freqs
, CPUFREQ_POSTCHANGE
);
292 mutex_unlock(&pas_switch_mutex
);
294 ppc_proc_freq
= freqs
.new * 1000ul;
298 static struct cpufreq_driver pas_cpufreq_driver
= {
299 .name
= "pas-cpufreq",
300 .flags
= CPUFREQ_CONST_LOOPS
,
301 .init
= pas_cpufreq_cpu_init
,
302 .exit
= pas_cpufreq_cpu_exit
,
303 .verify
= pas_cpufreq_verify
,
304 .target
= pas_cpufreq_target
,
305 .attr
= pas_cpu_freqs_attr
,
309 * module init and destoy
312 static int __init
pas_cpufreq_init(void)
314 if (!of_machine_is_compatible("PA6T-1682M") &&
315 !of_machine_is_compatible("pasemi,pwrficient"))
318 return cpufreq_register_driver(&pas_cpufreq_driver
);
321 static void __exit
pas_cpufreq_exit(void)
323 cpufreq_unregister_driver(&pas_cpufreq_driver
);
326 module_init(pas_cpufreq_init
);
327 module_exit(pas_cpufreq_exit
);
329 MODULE_LICENSE("GPL");
330 MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>");