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gerrit-public.fairphone.software / kernel / msm-4.9 / 27539bc441c833c958de1d0c04212cb78b2a08b0 / . / arch / arm / mach-bcm2835 / bcm2835.c
blob: 70f2f3925f0e8e08487abb20b55ba580c4026c43 [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>
Axel Lin57029412013-07-05 00:31:36 +0800[diff] [blame]17#include <linux/irqchip.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>
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]21
22#include <asm/mach/arch.h>
23#include <asm/mach/map.h>
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]24
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]25#define PM_RSTC 0x1c
Dom Cobley45e9d772012-10-27 21:14:50 -0600[diff] [blame]26#define PM_RSTS 0x20
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]27#define PM_WDOG 0x24
28
29#define PM_PASSWORD 0x5a000000
30#define PM_RSTC_WRCFG_MASK 0x00000030
31#define PM_RSTC_WRCFG_FULL_RESET 0x00000020
Dom Cobley45e9d772012-10-27 21:14:50 -0600[diff] [blame]32#define PM_RSTS_HADWRH_SET 0x00000040
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]33
Stephen Warrenf1ac9222013-03-11 22:40:18 -0600[diff] [blame]34#define BCM2835_PERIPH_PHYS 0x20000000
35#define BCM2835_PERIPH_VIRT 0xf0000000
36#define BCM2835_PERIPH_SIZE SZ_16M
37
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]38static void __iomem *wdt_regs;
39
40/*
41 * The machine restart method can be called from an atomic context so we won't
42 * be able to ioremap the regs then.
43 */
44static void bcm2835_setup_restart(void)
45{
46 struct device_node *np = of_find_compatible_node(NULL, NULL,
47 "brcm,bcm2835-pm-wdt");
48 if (WARN(!np, "unable to setup watchdog restart"))
49 return;
50
51 wdt_regs = of_iomap(np, 0);
52 WARN(!wdt_regs, "failed to remap watchdog regs");
53}
54
Robin Holt7b6d8642013-07-08 16:01:40 -0700[diff] [blame]55static void bcm2835_restart(enum reboot_mode mode, const char *cmd)
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]56{
57 u32 val;
58
59 if (!wdt_regs)
60 return;
61
62 /* use a timeout of 10 ticks (~150us) */
63 writel_relaxed(10 | PM_PASSWORD, wdt_regs + PM_WDOG);
64 val = readl_relaxed(wdt_regs + PM_RSTC);
65 val &= ~PM_RSTC_WRCFG_MASK;
66 val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET;
67 writel_relaxed(val, wdt_regs + PM_RSTC);
68
69 /* No sleeping, possibly atomic. */
70 mdelay(1);
71}
72
Dom Cobley45e9d772012-10-27 21:14:50 -0600[diff] [blame]73/*
74 * We can't really power off, but if we do the normal reset scheme, and
75 * indicate to bootcode.bin not to reboot, then most of the chip will be
76 * powered off.
77 */
78static void bcm2835_power_off(void)
79{
80 u32 val;
81
82 /*
83 * We set the watchdog hard reset bit here to distinguish this reset
84 * from the normal (full) reset. bootcode.bin will not reboot after a
85 * hard reset.
86 */
87 val = readl_relaxed(wdt_regs + PM_RSTS);
88 val &= ~PM_RSTC_WRCFG_MASK;
89 val |= PM_PASSWORD | PM_RSTS_HADWRH_SET;
90 writel_relaxed(val, wdt_regs + PM_RSTS);
91
92 /* Continue with normal reset mechanism */
Robin Holt7b6d8642013-07-08 16:01:40 -0700[diff] [blame]93 bcm2835_restart(REBOOT_HARD, "");
Dom Cobley45e9d772012-10-27 21:14:50 -0600[diff] [blame]94}
95
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]96static struct map_desc io_map __initdata = {
97 .virtual = BCM2835_PERIPH_VIRT,
98 .pfn = __phys_to_pfn(BCM2835_PERIPH_PHYS),
99 .length = BCM2835_PERIPH_SIZE,
100 .type = MT_DEVICE
101};
102
Domenico Andreolidd3c7542012-10-20 03:35:27 +0200[diff] [blame]103static void __init bcm2835_map_io(void)
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]104{
105 iotable_init(&io_map, 1);
106}
107
Domenico Andreolidd3c7542012-10-20 03:35:27 +0200[diff] [blame]108static void __init bcm2835_init(void)
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]109{
110 int ret;
111
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]112 bcm2835_setup_restart();
Dom Cobley45e9d772012-10-27 21:14:50 -0600[diff] [blame]113 if (wdt_regs)
114 pm_power_off = bcm2835_power_off;
115
Simon Arlott75fabc32012-09-10 23:26:15 -0600[diff] [blame]116 bcm2835_init_clocks();
117
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]118 ret = of_platform_populate(NULL, of_default_bus_match_table, NULL,
119 NULL);
120 if (ret) {
121 pr_err("of_platform_populate failed: %d\n", ret);
122 BUG();
123 }
124}
125
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]126static const char * const bcm2835_compat[] = {
127 "brcm,bcm2835",
128 NULL
129};
130
131DT_MACHINE_START(BCM2835, "BCM2835")
132 .map_io = bcm2835_map_io,
Axel Lin57029412013-07-05 00:31:36 +0800[diff] [blame]133 .init_irq = irqchip_init,
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]134 .init_machine = bcm2835_init,
Stephen Warrend0f1c7f2012-09-15 22:18:10 -0600[diff] [blame]135 .restart = bcm2835_restart,
Simon Arlottec9653b2012-05-26 01:04:43 -0600[diff] [blame]136 .dt_compat = bcm2835_compat
137MACHINE_END