1/*
2 * Copyright (C) 2008 Marvell International Ltd.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 */
9
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/sched.h>
13#include <linux/init.h>
14#include <linux/cpufreq.h>
15#include <linux/slab.h>
16#include <linux/io.h>
17
18#include <mach/generic.h>
19#include <mach/pxa3xx-regs.h>
20
21#define HSS_104M	(0)
22#define HSS_156M	(1)
23#define HSS_208M	(2)
24#define HSS_312M	(3)
25
26#define SMCFS_78M	(0)
27#define SMCFS_104M	(2)
28#define SMCFS_208M	(5)
29
30#define SFLFS_104M	(0)
31#define SFLFS_156M	(1)
32#define SFLFS_208M	(2)
33#define SFLFS_312M	(3)
34
35#define XSPCLK_156M	(0)
36#define XSPCLK_NONE	(3)
37
38#define DMCFS_26M	(0)
39#define DMCFS_260M	(3)
40
41struct pxa3xx_freq_info {
42	unsigned int cpufreq_mhz;
43	unsigned int core_xl : 5;
44	unsigned int core_xn : 3;
45	unsigned int hss : 2;
46	unsigned int dmcfs : 2;
47	unsigned int smcfs : 3;
48	unsigned int sflfs : 2;
49	unsigned int df_clkdiv : 3;
50
51	int	vcc_core;	/* in mV */
52	int	vcc_sram;	/* in mV */
53};
54
55#define OP(cpufreq, _xl, _xn, _hss, _dmc, _smc, _sfl, _dfi, vcore, vsram) \
56{									\
57	.cpufreq_mhz	= cpufreq,					\
58	.core_xl	= _xl,						\
59	.core_xn	= _xn,						\
60	.hss		= HSS_##_hss##M,				\
61	.dmcfs		= DMCFS_##_dmc##M,				\
62	.smcfs		= SMCFS_##_smc##M,				\
63	.sflfs		= SFLFS_##_sfl##M,				\
64	.df_clkdiv	= _dfi,						\
65	.vcc_core	= vcore,					\
66	.vcc_sram	= vsram,					\
67}
68
69static struct pxa3xx_freq_info pxa300_freqs[] = {
70	/*  CPU XL XN  HSS DMEM SMEM SRAM DFI VCC_CORE VCC_SRAM */
71	OP(104,  8, 1, 104, 260,  78, 104, 3, 1000, 1100), /* 104MHz */
72	OP(208, 16, 1, 104, 260, 104, 156, 2, 1000, 1100), /* 208MHz */
73	OP(416, 16, 2, 156, 260, 104, 208, 2, 1100, 1200), /* 416MHz */
74	OP(624, 24, 2, 208, 260, 208, 312, 3, 1375, 1400), /* 624MHz */
75};
76
77static struct pxa3xx_freq_info pxa320_freqs[] = {
78	/*  CPU XL XN  HSS DMEM SMEM SRAM DFI VCC_CORE VCC_SRAM */
79	OP(104,  8, 1, 104, 260,  78, 104, 3, 1000, 1100), /* 104MHz */
80	OP(208, 16, 1, 104, 260, 104, 156, 2, 1000, 1100), /* 208MHz */
81	OP(416, 16, 2, 156, 260, 104, 208, 2, 1100, 1200), /* 416MHz */
82	OP(624, 24, 2, 208, 260, 208, 312, 3, 1375, 1400), /* 624MHz */
83	OP(806, 31, 2, 208, 260, 208, 312, 3, 1400, 1400), /* 806MHz */
84};
85
86static unsigned int pxa3xx_freqs_num;
87static struct pxa3xx_freq_info *pxa3xx_freqs;
88static struct cpufreq_frequency_table *pxa3xx_freqs_table;
89
90static int setup_freqs_table(struct cpufreq_policy *policy,
91			     struct pxa3xx_freq_info *freqs, int num)
92{
93	struct cpufreq_frequency_table *table;
94	int i;
95
96	table = kzalloc((num + 1) * sizeof(*table), GFP_KERNEL);
97	if (table == NULL)
98		return -ENOMEM;
99
100	for (i = 0; i < num; i++) {
101		table[i].driver_data = i;
102		table[i].frequency = freqs[i].cpufreq_mhz * 1000;
103	}
104	table[num].driver_data = i;
105	table[num].frequency = CPUFREQ_TABLE_END;
106
107	pxa3xx_freqs = freqs;
108	pxa3xx_freqs_num = num;
109	pxa3xx_freqs_table = table;
110
111	return cpufreq_table_validate_and_show(policy, table);
112}
113
114static void __update_core_freq(struct pxa3xx_freq_info *info)
115{
116	uint32_t mask = ACCR_XN_MASK | ACCR_XL_MASK;
117	uint32_t accr = ACCR;
118	uint32_t xclkcfg;
119
120	accr &= ~(ACCR_XN_MASK | ACCR_XL_MASK | ACCR_XSPCLK_MASK);
121	accr |= ACCR_XN(info->core_xn) | ACCR_XL(info->core_xl);
122
123	/* No clock until core PLL is re-locked */
124	accr |= ACCR_XSPCLK(XSPCLK_NONE);
125
126	xclkcfg = (info->core_xn == 2) ? 0x3 : 0x2;	/* turbo bit */
127
128	ACCR = accr;
129	__asm__("mcr p14, 0, %0, c6, c0, 0\n" : : "r"(xclkcfg));
130
131	while ((ACSR & mask) != (accr & mask))
132		cpu_relax();
133}
134
135static void __update_bus_freq(struct pxa3xx_freq_info *info)
136{
137	uint32_t mask;
138	uint32_t accr = ACCR;
139
140	mask = ACCR_SMCFS_MASK | ACCR_SFLFS_MASK | ACCR_HSS_MASK |
141		ACCR_DMCFS_MASK;
142
143	accr &= ~mask;
144	accr |= ACCR_SMCFS(info->smcfs) | ACCR_SFLFS(info->sflfs) |
145		ACCR_HSS(info->hss) | ACCR_DMCFS(info->dmcfs);
146
147	ACCR = accr;
148
149	while ((ACSR & mask) != (accr & mask))
150		cpu_relax();
151}
152
153static unsigned int pxa3xx_cpufreq_get(unsigned int cpu)
154{
155	return pxa3xx_get_clk_frequency_khz(0);
156}
157
158static int pxa3xx_cpufreq_set(struct cpufreq_policy *policy, unsigned int index)
159{
160	struct pxa3xx_freq_info *next;
161	unsigned long flags;
162
163	if (policy->cpu != 0)
164		return -EINVAL;
165
166	next = &pxa3xx_freqs[index];
167
168	local_irq_save(flags);
169	__update_core_freq(next);
170	__update_bus_freq(next);
171	local_irq_restore(flags);
172
173	return 0;
174}
175
176static int pxa3xx_cpufreq_init(struct cpufreq_policy *policy)
177{
178	int ret = -EINVAL;
179
180	/* set default policy and cpuinfo */
181	policy->min = policy->cpuinfo.min_freq = 104000;
182	policy->max = policy->cpuinfo.max_freq =
183		(cpu_is_pxa320()) ? 806000 : 624000;
184	policy->cpuinfo.transition_latency = 1000; /* FIXME: 1 ms, assumed */
185
186	if (cpu_is_pxa300() || cpu_is_pxa310())
187		ret = setup_freqs_table(policy, pxa300_freqs,
188					ARRAY_SIZE(pxa300_freqs));
189
190	if (cpu_is_pxa320())
191		ret = setup_freqs_table(policy, pxa320_freqs,
192					ARRAY_SIZE(pxa320_freqs));
193
194	if (ret) {
195		pr_err("failed to setup frequency table\n");
196		return ret;
197	}
198
199	pr_info("CPUFREQ support for PXA3xx initialized\n");
200	return 0;
201}
202
203static struct cpufreq_driver pxa3xx_cpufreq_driver = {
204	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK,
205	.verify		= cpufreq_generic_frequency_table_verify,
206	.target_index	= pxa3xx_cpufreq_set,
207	.init		= pxa3xx_cpufreq_init,
208	.get		= pxa3xx_cpufreq_get,
209	.name		= "pxa3xx-cpufreq",
210};
211
212static int __init cpufreq_init(void)
213{
214	if (cpu_is_pxa3xx())
215		return cpufreq_register_driver(&pxa3xx_cpufreq_driver);
216
217	return 0;
218}
219module_init(cpufreq_init);
220
221static void __exit cpufreq_exit(void)
222{
223	cpufreq_unregister_driver(&pxa3xx_cpufreq_driver);
224}
225module_exit(cpufreq_exit);
226
227MODULE_DESCRIPTION("CPU frequency scaling driver for PXA3xx");
228MODULE_LICENSE("GPL");
229