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gerrit-public.fairphone.software / kernel / msm-4.9 / c25d8cbcd840b2c9774a285ea728e72dd56aea2e / . / arch / arm / mach-shmobile / pm-rcar.c
blob: 00022ee56f80dc3075e59a6a93e05acb09a38c80 [file] [log] [blame]
Magnus Damma6557eb2014-01-15 16:43:08 +0900[diff] [blame]1/*
2 * R-Car SYSC Power management support
3 *
4 * Copyright (C) 2014 Magnus Damm
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive
8 * for more details.
9 */
10
11#include <linux/delay.h>
12#include <linux/err.h>
13#include <linux/mm.h>
14#include <linux/spinlock.h>
15#include <asm/io.h>
Magnus Damm585c09d2014-06-17 16:47:53 +0900[diff] [blame]16#include "pm-rcar.h"
Magnus Damma6557eb2014-01-15 16:43:08 +0900[diff] [blame]17
Magnus Damma6557eb2014-01-15 16:43:08 +0900[diff] [blame]18/* SYSC */
19#define SYSCSR 0x00
20#define SYSCISR 0x04
21#define SYSCISCR 0x08
22
23#define PWRSR_OFFS 0x00
24#define PWROFFCR_OFFS 0x04
25#define PWRONCR_OFFS 0x0c
26#define PWRER_OFFS 0x14
27
28#define SYSCSR_RETRIES 100
29#define SYSCSR_DELAY_US 1
30
31#define SYSCISR_RETRIES 1000
32#define SYSCISR_DELAY_US 1
33
Magnus Dammc4ca5d82014-02-24 14:52:12 +0900[diff] [blame]34static void __iomem *rcar_sysc_base;
Magnus Damma6557eb2014-01-15 16:43:08 +0900[diff] [blame]35static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */
36
37static int rcar_sysc_pwr_on_off(struct rcar_sysc_ch *sysc_ch,
38 int sr_bit, int reg_offs)
39{
40 int k;
41
42 for (k = 0; k < SYSCSR_RETRIES; k++) {
43 if (ioread32(rcar_sysc_base + SYSCSR) & (1 << sr_bit))
44 break;
45 udelay(SYSCSR_DELAY_US);
46 }
47
48 if (k == SYSCSR_RETRIES)
49 return -EAGAIN;
50
51 iowrite32(1 << sysc_ch->chan_bit,
52 rcar_sysc_base + sysc_ch->chan_offs + reg_offs);
53
54 return 0;
55}
56
57static int rcar_sysc_pwr_off(struct rcar_sysc_ch *sysc_ch)
58{
59 return rcar_sysc_pwr_on_off(sysc_ch, 0, PWROFFCR_OFFS);
60}
61
62static int rcar_sysc_pwr_on(struct rcar_sysc_ch *sysc_ch)
63{
64 return rcar_sysc_pwr_on_off(sysc_ch, 1, PWRONCR_OFFS);
65}
66
67static int rcar_sysc_update(struct rcar_sysc_ch *sysc_ch,
68 int (*on_off_fn)(struct rcar_sysc_ch *))
69{
70 unsigned int isr_mask = 1 << sysc_ch->isr_bit;
71 unsigned int chan_mask = 1 << sysc_ch->chan_bit;
72 unsigned int status;
73 unsigned long flags;
74 int ret = 0;
75 int k;
76
77 spin_lock_irqsave(&rcar_sysc_lock, flags);
78
79 iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
80
81 do {
82 ret = on_off_fn(sysc_ch);
83 if (ret)
84 goto out;
85
86 status = ioread32(rcar_sysc_base +
87 sysc_ch->chan_offs + PWRER_OFFS);
88 } while (status & chan_mask);
89
90 for (k = 0; k < SYSCISR_RETRIES; k++) {
91 if (ioread32(rcar_sysc_base + SYSCISR) & isr_mask)
92 break;
93 udelay(SYSCISR_DELAY_US);
94 }
95
96 if (k == SYSCISR_RETRIES)
97 ret = -EIO;
98
99 iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
100
101 out:
102 spin_unlock_irqrestore(&rcar_sysc_lock, flags);
103
104 pr_debug("sysc power domain %d: %08x -> %d\n",
105 sysc_ch->isr_bit, ioread32(rcar_sysc_base + SYSCISR), ret);
106 return ret;
107}
108
109int rcar_sysc_power_down(struct rcar_sysc_ch *sysc_ch)
110{
111 return rcar_sysc_update(sysc_ch, rcar_sysc_pwr_off);
112}
113
114int rcar_sysc_power_up(struct rcar_sysc_ch *sysc_ch)
115{
116 return rcar_sysc_update(sysc_ch, rcar_sysc_pwr_on);
117}
118
119bool rcar_sysc_power_is_off(struct rcar_sysc_ch *sysc_ch)
120{
121 unsigned int st;
122
123 st = ioread32(rcar_sysc_base + sysc_ch->chan_offs + PWRSR_OFFS);
124 if (st & (1 << sysc_ch->chan_bit))
125 return true;
126
127 return false;
128}
129
130void __iomem *rcar_sysc_init(phys_addr_t base)
131{
132 rcar_sysc_base = ioremap_nocache(base, PAGE_SIZE);
133 if (!rcar_sysc_base)
134 panic("unable to ioremap R-Car SYSC hardware block\n");
135
136 return rcar_sysc_base;
137}