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ec9653b8 SA |
1 | /* |
2 | * Copyright (C) 2010 Broadcom | |
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 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | */ | |
14 | ||
d0f1c7ff | 15 | #include <linux/delay.h> |
ec9653b8 | 16 | #include <linux/init.h> |
89214f00 | 17 | #include <linux/irqchip/bcm2835.h> |
d0f1c7ff | 18 | #include <linux/of_address.h> |
ec9653b8 | 19 | #include <linux/of_platform.h> |
75fabc3f | 20 | #include <linux/clk/bcm2835.h> |
c1b724f6 | 21 | #include <linux/clocksource.h> |
ec9653b8 SA |
22 | |
23 | #include <asm/mach/arch.h> | |
24 | #include <asm/mach/map.h> | |
ec9653b8 SA |
25 | |
26 | #include <mach/bcm2835_soc.h> | |
27 | ||
d0f1c7ff | 28 | #define PM_RSTC 0x1c |
45e9d77a | 29 | #define PM_RSTS 0x20 |
d0f1c7ff SW |
30 | #define PM_WDOG 0x24 |
31 | ||
32 | #define PM_PASSWORD 0x5a000000 | |
33 | #define PM_RSTC_WRCFG_MASK 0x00000030 | |
34 | #define PM_RSTC_WRCFG_FULL_RESET 0x00000020 | |
45e9d77a | 35 | #define PM_RSTS_HADWRH_SET 0x00000040 |
d0f1c7ff SW |
36 | |
37 | static void __iomem *wdt_regs; | |
38 | ||
39 | /* | |
40 | * The machine restart method can be called from an atomic context so we won't | |
41 | * be able to ioremap the regs then. | |
42 | */ | |
43 | static void bcm2835_setup_restart(void) | |
44 | { | |
45 | struct device_node *np = of_find_compatible_node(NULL, NULL, | |
46 | "brcm,bcm2835-pm-wdt"); | |
47 | if (WARN(!np, "unable to setup watchdog restart")) | |
48 | return; | |
49 | ||
50 | wdt_regs = of_iomap(np, 0); | |
51 | WARN(!wdt_regs, "failed to remap watchdog regs"); | |
52 | } | |
53 | ||
54 | static void bcm2835_restart(char mode, const char *cmd) | |
55 | { | |
56 | u32 val; | |
57 | ||
58 | if (!wdt_regs) | |
59 | return; | |
60 | ||
61 | /* use a timeout of 10 ticks (~150us) */ | |
62 | writel_relaxed(10 | PM_PASSWORD, wdt_regs + PM_WDOG); | |
63 | val = readl_relaxed(wdt_regs + PM_RSTC); | |
64 | val &= ~PM_RSTC_WRCFG_MASK; | |
65 | val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET; | |
66 | writel_relaxed(val, wdt_regs + PM_RSTC); | |
67 | ||
68 | /* No sleeping, possibly atomic. */ | |
69 | mdelay(1); | |
70 | } | |
71 | ||
45e9d77a DC |
72 | /* |
73 | * We can't really power off, but if we do the normal reset scheme, and | |
74 | * indicate to bootcode.bin not to reboot, then most of the chip will be | |
75 | * powered off. | |
76 | */ | |
77 | static void bcm2835_power_off(void) | |
78 | { | |
79 | u32 val; | |
80 | ||
81 | /* | |
82 | * We set the watchdog hard reset bit here to distinguish this reset | |
83 | * from the normal (full) reset. bootcode.bin will not reboot after a | |
84 | * hard reset. | |
85 | */ | |
86 | val = readl_relaxed(wdt_regs + PM_RSTS); | |
87 | val &= ~PM_RSTC_WRCFG_MASK; | |
88 | val |= PM_PASSWORD | PM_RSTS_HADWRH_SET; | |
89 | writel_relaxed(val, wdt_regs + PM_RSTS); | |
90 | ||
91 | /* Continue with normal reset mechanism */ | |
92 | bcm2835_restart(0, ""); | |
93 | } | |
94 | ||
ec9653b8 SA |
95 | static struct map_desc io_map __initdata = { |
96 | .virtual = BCM2835_PERIPH_VIRT, | |
97 | .pfn = __phys_to_pfn(BCM2835_PERIPH_PHYS), | |
98 | .length = BCM2835_PERIPH_SIZE, | |
99 | .type = MT_DEVICE | |
100 | }; | |
101 | ||
dd3c7548 | 102 | static void __init bcm2835_map_io(void) |
ec9653b8 SA |
103 | { |
104 | iotable_init(&io_map, 1); | |
105 | } | |
106 | ||
dd3c7548 | 107 | static void __init bcm2835_init(void) |
ec9653b8 SA |
108 | { |
109 | int ret; | |
110 | ||
d0f1c7ff | 111 | bcm2835_setup_restart(); |
45e9d77a DC |
112 | if (wdt_regs) |
113 | pm_power_off = bcm2835_power_off; | |
114 | ||
75fabc3f SA |
115 | bcm2835_init_clocks(); |
116 | ||
ec9653b8 SA |
117 | ret = of_platform_populate(NULL, of_default_bus_match_table, NULL, |
118 | NULL); | |
119 | if (ret) { | |
120 | pr_err("of_platform_populate failed: %d\n", ret); | |
121 | BUG(); | |
122 | } | |
123 | } | |
124 | ||
ec9653b8 SA |
125 | static const char * const bcm2835_compat[] = { |
126 | "brcm,bcm2835", | |
127 | NULL | |
128 | }; | |
129 | ||
130 | DT_MACHINE_START(BCM2835, "BCM2835") | |
131 | .map_io = bcm2835_map_io, | |
132 | .init_irq = bcm2835_init_irq, | |
133 | .handle_irq = bcm2835_handle_irq, | |
134 | .init_machine = bcm2835_init, | |
c1b724f6 | 135 | .init_time = clocksource_of_init, |
d0f1c7ff | 136 | .restart = bcm2835_restart, |
ec9653b8 SA |
137 | .dt_compat = bcm2835_compat |
138 | MACHINE_END |