x86/xen: resume timer irqs early
[linux/fpc-iii.git] / arch / arm / mach-bcm2835 / bcm2835.c
blob40686d7ef500223765a1a08f6beccfad9a2847f6
1 /*
2 * Copyright (C) 2010 Broadcom
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.
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.
15 #include <linux/delay.h>
16 #include <linux/init.h>
17 #include <linux/irqchip/bcm2835.h>
18 #include <linux/of_address.h>
19 #include <linux/of_platform.h>
20 #include <linux/clk/bcm2835.h>
21 #include <linux/clocksource.h>
23 #include <asm/mach/arch.h>
24 #include <asm/mach/map.h>
26 #define PM_RSTC 0x1c
27 #define PM_RSTS 0x20
28 #define PM_WDOG 0x24
30 #define PM_PASSWORD 0x5a000000
31 #define PM_RSTC_WRCFG_MASK 0x00000030
32 #define PM_RSTC_WRCFG_FULL_RESET 0x00000020
33 #define PM_RSTS_HADWRH_SET 0x00000040
35 #define BCM2835_PERIPH_PHYS 0x20000000
36 #define BCM2835_PERIPH_VIRT 0xf0000000
37 #define BCM2835_PERIPH_SIZE SZ_16M
39 static void __iomem *wdt_regs;
42 * The machine restart method can be called from an atomic context so we won't
43 * be able to ioremap the regs then.
45 static void bcm2835_setup_restart(void)
47 struct device_node *np = of_find_compatible_node(NULL, NULL,
48 "brcm,bcm2835-pm-wdt");
49 if (WARN(!np, "unable to setup watchdog restart"))
50 return;
52 wdt_regs = of_iomap(np, 0);
53 WARN(!wdt_regs, "failed to remap watchdog regs");
56 static void bcm2835_restart(enum reboot_mode mode, const char *cmd)
58 u32 val;
60 if (!wdt_regs)
61 return;
63 /* use a timeout of 10 ticks (~150us) */
64 writel_relaxed(10 | PM_PASSWORD, wdt_regs + PM_WDOG);
65 val = readl_relaxed(wdt_regs + PM_RSTC);
66 val &= ~PM_RSTC_WRCFG_MASK;
67 val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET;
68 writel_relaxed(val, wdt_regs + PM_RSTC);
70 /* No sleeping, possibly atomic. */
71 mdelay(1);
75 * We can't really power off, but if we do the normal reset scheme, and
76 * indicate to bootcode.bin not to reboot, then most of the chip will be
77 * powered off.
79 static void bcm2835_power_off(void)
81 u32 val;
84 * We set the watchdog hard reset bit here to distinguish this reset
85 * from the normal (full) reset. bootcode.bin will not reboot after a
86 * hard reset.
88 val = readl_relaxed(wdt_regs + PM_RSTS);
89 val &= ~PM_RSTC_WRCFG_MASK;
90 val |= PM_PASSWORD | PM_RSTS_HADWRH_SET;
91 writel_relaxed(val, wdt_regs + PM_RSTS);
93 /* Continue with normal reset mechanism */
94 bcm2835_restart(REBOOT_HARD, "");
97 static struct map_desc io_map __initdata = {
98 .virtual = BCM2835_PERIPH_VIRT,
99 .pfn = __phys_to_pfn(BCM2835_PERIPH_PHYS),
100 .length = BCM2835_PERIPH_SIZE,
101 .type = MT_DEVICE
104 static void __init bcm2835_map_io(void)
106 iotable_init(&io_map, 1);
109 static void __init bcm2835_init(void)
111 int ret;
113 bcm2835_setup_restart();
114 if (wdt_regs)
115 pm_power_off = bcm2835_power_off;
117 bcm2835_init_clocks();
119 ret = of_platform_populate(NULL, of_default_bus_match_table, NULL,
120 NULL);
121 if (ret) {
122 pr_err("of_platform_populate failed: %d\n", ret);
123 BUG();
127 static const char * const bcm2835_compat[] = {
128 "brcm,bcm2835",
129 NULL
132 DT_MACHINE_START(BCM2835, "BCM2835")
133 .map_io = bcm2835_map_io,
134 .init_irq = bcm2835_init_irq,
135 .handle_irq = bcm2835_handle_irq,
136 .init_machine = bcm2835_init,
137 .init_time = clocksource_of_init,
138 .restart = bcm2835_restart,
139 .dt_compat = bcm2835_compat
140 MACHINE_END