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