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review.evervolv.com / android_kernel_oneplus_msm8996 / c1b724f6659a7e9e32f8fcf6409d053e1b7bccad / . / arch / arm / mach-bcm2835 / bcm2835.c
blob: d615a61e902ced99205cb885fe849e0aee007011 [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
26#include <mach/bcm2835_soc.h>
27
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]28#define PM_RSTC 0x1c
29#define PM_WDOG 0x24
30
31#define PM_PASSWORD 0x5a000000
32#define PM_RSTC_WRCFG_MASK 0x00000030
33#define PM_RSTC_WRCFG_FULL_RESET 0x00000020
34
35static void __iomem *wdt_regs;
36
37/*
38 * The machine restart method can be called from an atomic context so we won't
39 * be able to ioremap the regs then.
40 */
41static void bcm2835_setup_restart(void)
42{
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"))
46 return;
47
48 wdt_regs = of_iomap(np, 0);
49 WARN(!wdt_regs, "failed to remap watchdog regs");
50}
51
52static void bcm2835_restart(char mode, const char *cmd)
53{
54 u32 val;
55
56 if (!wdt_regs)
57 return;
58
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);
65
66 /* No sleeping, possibly atomic. */
67 mdelay(1);
68}
69
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]70static struct map_desc io_map __initdata = {
71 .virtual = BCM2835_PERIPH_VIRT,
72 .pfn = __phys_to_pfn(BCM2835_PERIPH_PHYS),
73 .length = BCM2835_PERIPH_SIZE,
74 .type = MT_DEVICE
75};
76
Domenico Andreolidd3c7542012-10-20 03:35:27 +0200[diff] [blame]77static void __init bcm2835_map_io(void)
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]78{
79 iotable_init(&io_map, 1);
80}
81
Domenico Andreolidd3c7542012-10-20 03:35:27 +0200[diff] [blame]82static void __init bcm2835_init(void)
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]83{
84 int ret;
85
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]86 bcm2835_setup_restart();
Simon Arlott75fabc32012-09-10 23:26:15 -0600[diff] [blame]87 bcm2835_init_clocks();
88
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]89 ret = of_platform_populate(NULL, of_default_bus_match_table, NULL,
90 NULL);
91 if (ret) {
92 pr_err("of_platform_populate failed: %d\n", ret);
93 BUG();
94 }
95}
96
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]97static const char * const bcm2835_compat[] = {
98 "brcm,bcm2835",
99 NULL
100};
101
102DT_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,
Stephen Warrenc1b724f2013-01-03 20:23:13 -0700[diff] [blame^]107 .init_time = clocksource_of_init,
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]108 .restart = bcm2835_restart,
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]109 .dt_compat = bcm2835_compat
110MACHINE_END