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gerrit-public.fairphone.software / kernel / msm-4.9 / e5137b50a0640009fd63a3e65c14bc6e1be8796a / . / arch / arm / mach-bcm2835 / bcm2835.c
blob: 40686d7ef500223765a1a08f6beccfad9a2847f6 [file] [log] [blame]
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]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
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]15#include <linux/delay.h>
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]16#include <linux/init.h>
Simon Arlott89214f02012-09-12 19:57:26 -0600[diff] [blame]17#include <linux/irqchip/bcm2835.h>
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]18#include <linux/of_address.h>
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]19#include <linux/of_platform.h>
Simon Arlott75fabc32012-09-10 23:26:15 -0600[diff] [blame]20#include <linux/clk/bcm2835.h>
Stephen Warrenc1b724f2013-01-03 20:23:13 -0700[diff] [blame]21#include <linux/clocksource.h>
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]22
23#include <asm/mach/arch.h>
24#include <asm/mach/map.h>
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]25
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]26#define PM_RSTC 0x1c
Dom Cobley45e9d772012-10-27 21:14:50 -0600[diff] [blame]27#define PM_RSTS 0x20
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]28#define PM_WDOG 0x24
29
30#define PM_PASSWORD 0x5a000000
31#define PM_RSTC_WRCFG_MASK 0x00000030
32#define PM_RSTC_WRCFG_FULL_RESET 0x00000020
Dom Cobley45e9d772012-10-27 21:14:50 -0600[diff] [blame]33#define PM_RSTS_HADWRH_SET 0x00000040
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]34
Stephen Warrenf1ac9222013-03-11 22:40:18 -0600[diff] [blame]35#define BCM2835_PERIPH_PHYS 0x20000000
36#define BCM2835_PERIPH_VIRT 0xf0000000
37#define BCM2835_PERIPH_SIZE SZ_16M
38
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]39static void __iomem *wdt_regs;
40
41/*
42 * The machine restart method can be called from an atomic context so we won't
43 * be able to ioremap the regs then.
44 */
45static void bcm2835_setup_restart(void)
46{
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;
51
52 wdt_regs = of_iomap(np, 0);
53 WARN(!wdt_regs, "failed to remap watchdog regs");
54}
55
Robin Holt7b6d8642013-07-08 16:01:40 -0700[diff] [blame]56static void bcm2835_restart(enum reboot_mode mode, const char *cmd)
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]57{
58 u32 val;
59
60 if (!wdt_regs)
61 return;
62
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);
69
70 /* No sleeping, possibly atomic. */
71 mdelay(1);
72}
73
Dom Cobley45e9d772012-10-27 21:14:50 -0600[diff] [blame]74/*
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.
78 */
79static void bcm2835_power_off(void)
80{
81 u32 val;
82
83 /*
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.
87 */
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);
92
93 /* Continue with normal reset mechanism */
Robin Holt7b6d8642013-07-08 16:01:40 -0700[diff] [blame]94 bcm2835_restart(REBOOT_HARD, "");
Dom Cobley45e9d772012-10-27 21:14:50 -0600[diff] [blame]95}
96
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]97static 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
102};
103
Domenico Andreolidd3c7542012-10-20 03:35:27 +0200[diff] [blame]104static void __init bcm2835_map_io(void)
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]105{
106 iotable_init(&io_map, 1);
107}
108
Domenico Andreolidd3c7542012-10-20 03:35:27 +0200[diff] [blame]109static void __init bcm2835_init(void)
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]110{
111 int ret;
112
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]113 bcm2835_setup_restart();
Dom Cobley45e9d772012-10-27 21:14:50 -0600[diff] [blame]114 if (wdt_regs)
115 pm_power_off = bcm2835_power_off;
116
Simon Arlott75fabc32012-09-10 23:26:15 -0600[diff] [blame]117 bcm2835_init_clocks();
118
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]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();
124 }
125}
126
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]127static const char * const bcm2835_compat[] = {
128 "brcm,bcm2835",
129 NULL
130};
131
132DT_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,
Stephen Warrenc1b724f2013-01-03 20:23:13 -0700[diff] [blame]137 .init_time = clocksource_of_init,
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]138 .restart = bcm2835_restart,
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]139 .dt_compat = bcm2835_compat
140MACHINE_END