summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-pxa/cpufreq-pxa3xx.c
blob: 149cdd9aee4d51d23977d769d1a3d041897f12ee (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
/*
 * linux/arch/arm/mach-pxa/cpufreq-pxa3xx.c
 *
 * Copyright (C) 2008 Marvell International Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/cpufreq.h>

#include <mach/pxa3xx-regs.h>

#include "generic.h"

#define HSS_104M	(0)
#define HSS_156M	(1)
#define HSS_208M	(2)
#define HSS_312M	(3)

#define SMCFS_78M	(0)
#define SMCFS_104M	(2)
#define SMCFS_208M	(5)

#define SFLFS_104M	(0)
#define SFLFS_156M	(1)
#define SFLFS_208M	(2)
#define SFLFS_312M	(3)

#define XSPCLK_156M	(0)
#define XSPCLK_NONE	(3)

#define DMCFS_26M	(0)
#define DMCFS_260M	(3)

struct pxa3xx_freq_info {
	unsigned int cpufreq_mhz;
	unsigned int core_xl : 5;
	unsigned int core_xn : 3;
	unsigned int hss : 2;
	unsigned int dmcfs : 2;
	unsigned int smcfs : 3;
	unsigned int sflfs : 2;
	unsigned int df_clkdiv : 3;

	int	vcc_core;	/* in mV */
	int	vcc_sram;	/* in mV */
};

#define OP(cpufreq, _xl, _xn, _hss, _dmc, _smc, _sfl, _dfi, vcore, vsram) \
{									\
	.cpufreq_mhz	= cpufreq,					\
	.core_xl	= _xl,						\
	.core_xn	= _xn,						\
	.hss		= HSS_##_hss##M,				\
	.dmcfs		= DMCFS_##_dmc##M,				\
	.smcfs		= SMCFS_##_smc##M,				\
	.sflfs		= SFLFS_##_sfl##M,				\
	.df_clkdiv	= _dfi,						\
	.vcc_core	= vcore,					\
	.vcc_sram	= vsram,					\
}

static struct pxa3xx_freq_info pxa300_freqs[] = {
	/*  CPU XL XN  HSS DMEM SMEM SRAM DFI VCC_CORE VCC_SRAM */
	OP(104,  8, 1, 104, 260,  78, 104, 3, 1000, 1100), /* 104MHz */
	OP(208, 16, 1, 104, 260, 104, 156, 2, 1000, 1100), /* 208MHz */
	OP(416, 16, 2, 156, 260, 104, 208, 2, 1100, 1200), /* 416MHz */
	OP(624, 24, 2, 208, 260, 208, 312, 3, 1375, 1400), /* 624MHz */
};

static struct pxa3xx_freq_info pxa320_freqs[] = {
	/*  CPU XL XN  HSS DMEM SMEM SRAM DFI VCC_CORE VCC_SRAM */
	OP(104,  8, 1, 104, 260,  78, 104, 3, 1000, 1100), /* 104MHz */
	OP(208, 16, 1, 104, 260, 104, 156, 2, 1000, 1100), /* 208MHz */
	OP(416, 16, 2, 156, 260, 104, 208, 2, 1100, 1200), /* 416MHz */
	OP(624, 24, 2, 208, 260, 208, 312, 3, 1375, 1400), /* 624MHz */
	OP(806, 31, 2, 208, 260, 208, 312, 3, 1400, 1400), /* 806MHz */
};

static unsigned int pxa3xx_freqs_num;
static struct pxa3xx_freq_info *pxa3xx_freqs;
static struct cpufreq_frequency_table *pxa3xx_freqs_table;

static int setup_freqs_table(struct cpufreq_policy *policy,
			     struct pxa3xx_freq_info *freqs, int num)
{
	struct cpufreq_frequency_table *table;
	int i;

	table = kzalloc((num + 1) * sizeof(*table), GFP_KERNEL);
	if (table == NULL)
		return -ENOMEM;

	for (i = 0; i < num; i++) {
		table[i].index = i;
		table[i].frequency = freqs[i].cpufreq_mhz * 1000;
	}
	table[num].index = i;
	table[num].frequency = CPUFREQ_TABLE_END;

	pxa3xx_freqs = freqs;
	pxa3xx_freqs_num = num;
	pxa3xx_freqs_table = table;

	return cpufreq_frequency_table_cpuinfo(policy, table);
}

static void __update_core_freq(struct pxa3xx_freq_info *info)
{
	uint32_t mask = ACCR_XN_MASK | ACCR_XL_MASK;
	uint32_t accr = ACCR;
	uint32_t xclkcfg;

	accr &= ~(ACCR_XN_MASK | ACCR_XL_MASK | ACCR_XSPCLK_MASK);
	accr |= ACCR_XN(info->core_xn) | ACCR_XL(info->core_xl);

	/* No clock until core PLL is re-locked */
	accr |= ACCR_XSPCLK(XSPCLK_NONE);

	xclkcfg = (info->core_xn == 2) ? 0x3 : 0x2;	/* turbo bit */

	ACCR = accr;
	__asm__("mcr p14, 0, %0, c6, c0, 0\n" : : "r"(xclkcfg));

	while ((ACSR & mask) != (accr & mask))
		cpu_relax();
}

static void __update_bus_freq(struct pxa3xx_freq_info *info)
{
	uint32_t mask;
	uint32_t accr = ACCR;

	mask = ACCR_SMCFS_MASK | ACCR_SFLFS_MASK | ACCR_HSS_MASK |
		ACCR_DMCFS_MASK;

	accr &= ~mask;
	accr |= ACCR_SMCFS(info->smcfs) | ACCR_SFLFS(info->sflfs) |
		ACCR_HSS(info->hss) | ACCR_DMCFS(info->dmcfs);

	ACCR = accr;

	while ((ACSR & mask) != (accr & mask))
		cpu_relax();
}

static int pxa3xx_cpufreq_verify(struct cpufreq_policy *policy)
{
	return cpufreq_frequency_table_verify(policy, pxa3xx_freqs_table);
}

static unsigned int pxa3xx_cpufreq_get(unsigned int cpu)
{
	return get_clk_frequency_khz(0);
}

static int pxa3xx_cpufreq_set(struct cpufreq_policy *policy,
			      unsigned int target_freq,
			      unsigned int relation)
{
	struct pxa3xx_freq_info *next;
	struct cpufreq_freqs freqs;
	unsigned long flags;
	int idx;

	if (policy->cpu != 0)
		return -EINVAL;

	/* Lookup the next frequency */
	if (cpufreq_frequency_table_target(policy, pxa3xx_freqs_table,
				target_freq, relation, &idx))
		return -EINVAL;

	next = &pxa3xx_freqs[idx];

	freqs.old = policy->cur;
	freqs.new = next->cpufreq_mhz * 1000;
	freqs.cpu = policy->cpu;

	pr_debug("CPU frequency from %d MHz to %d MHz%s\n",
			freqs.old / 1000, freqs.new / 1000,
			(freqs.old == freqs.new) ? " (skipped)" : "");

	if (freqs.old == target_freq)
		return 0;

	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);

	local_irq_save(flags);
	__update_core_freq(next);
	__update_bus_freq(next);
	local_irq_restore(flags);

	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);

	return 0;
}

static __init int pxa3xx_cpufreq_init(struct cpufreq_policy *policy)
{
	int ret = -EINVAL;

	/* set default policy and cpuinfo */
	policy->cpuinfo.min_freq = 104000;
	policy->cpuinfo.max_freq = (cpu_is_pxa320()) ? 806000 : 624000;
	policy->cpuinfo.transition_latency = 1000; /* FIXME: 1 ms, assumed */
	policy->cur = policy->min = policy->max = get_clk_frequency_khz(0);

	if (cpu_is_pxa300() || cpu_is_pxa310())
		ret = setup_freqs_table(policy, ARRAY_AND_SIZE(pxa300_freqs));

	if (cpu_is_pxa320())
		ret = setup_freqs_table(policy, ARRAY_AND_SIZE(pxa320_freqs));

	if (ret) {
		pr_err("failed to setup frequency table\n");
		return ret;
	}

	pr_info("CPUFREQ support for PXA3xx initialized\n");
	return 0;
}

static struct cpufreq_driver pxa3xx_cpufreq_driver = {
	.verify		= pxa3xx_cpufreq_verify,
	.target		= pxa3xx_cpufreq_set,
	.init		= pxa3xx_cpufreq_init,
	.get		= pxa3xx_cpufreq_get,
	.name		= "pxa3xx-cpufreq",
};

static int __init cpufreq_init(void)
{
	if (cpu_is_pxa3xx())
		return cpufreq_register_driver(&pxa3xx_cpufreq_driver);

	return 0;
}
module_init(cpufreq_init);

static void __exit cpufreq_exit(void)
{
	cpufreq_unregister_driver(&pxa3xx_cpufreq_driver);
}
module_exit(cpufreq_exit);

MODULE_DESCRIPTION("CPU frequency scaling driver for PXA3xx");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud