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/bcm2835_timer.h>
21 #include <linux/clk/bcm2835.h>
23 #include <asm/mach/arch.h>
24 #include <asm/mach/map.h>
26 #include <mach/bcm2835_soc.h>
31 #define PM_PASSWORD 0x5a000000
32 #define PM_RSTC_WRCFG_MASK 0x00000030
33 #define PM_RSTC_WRCFG_FULL_RESET 0x00000020
35 static void __iomem *wdt_regs;
38 * The machine restart method can be called from an atomic context so we won't
39 * be able to ioremap the regs then.
41 static void bcm2835_setup_restart(void)
43 struct device_node *np = of_find_compatible_node(NULL, NULL,
44 "brcm,bcm2835-pm-wdt");
45 if (WARN(!np, "unable to setup watchdog restart"))
48 wdt_regs = of_iomap(np, 0);
49 WARN(!wdt_regs, "failed to remap watchdog regs");
52 static void bcm2835_restart(char mode, const char *cmd)
59 /* use a timeout of 10 ticks (~150us) */
60 writel_relaxed(10 | PM_PASSWORD, wdt_regs + PM_WDOG);
61 val = readl_relaxed(wdt_regs + PM_RSTC);
62 val &= ~PM_RSTC_WRCFG_MASK;
63 val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET;
64 writel_relaxed(val, wdt_regs + PM_RSTC);
66 /* No sleeping, possibly atomic. */
70 static struct map_desc io_map __initdata = {
71 .virtual = BCM2835_PERIPH_VIRT,
72 .pfn = __phys_to_pfn(BCM2835_PERIPH_PHYS),
73 .length = BCM2835_PERIPH_SIZE,
77 static void __init bcm2835_map_io(void)
79 iotable_init(&io_map, 1);
82 static void __init bcm2835_init(void)
86 bcm2835_setup_restart();
87 bcm2835_init_clocks();
89 ret = of_platform_populate(NULL, of_default_bus_match_table, NULL,
92 pr_err("of_platform_populate failed: %d\n", ret);
97 static const char * const bcm2835_compat[] = {
102 DT_MACHINE_START(BCM2835, "BCM2835")
103 .map_io = bcm2835_map_io,
104 .init_irq = bcm2835_init_irq,
105 .handle_irq = bcm2835_handle_irq,
106 .init_machine = bcm2835_init,
107 .timer = &bcm2835_timer,
108 .restart = bcm2835_restart,
109 .dt_compat = bcm2835_compat