projects / mirror_ubuntu-artful-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| af75655c JI |
1 | /* |
| 2 | * Copyright (c) 2011 Picochip Ltd., Jamie Iles | |
| 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 version 2 as | |
| 6 | * published by the Free Software Foundation. | |
| 7 | * | |
| 8 | * All enquiries to support@picochip.com | |
| 9 | */ | |
| 1b46f878 | 10 | #include <linux/delay.h> |
| af75655c JI |
11 | #include <linux/of.h> |
| 12 | #include <linux/of_address.h> | |
| 7b6d864b | 13 | #include <linux/reboot.h> |
| af75655c JI |
14 | |
| 15 | #include <asm/mach/arch.h> | |
| 8f37a0b4 | 16 | #include <asm/mach/map.h> |
| af75655c | 17 | |
| 06413f1e RH |
18 | #define PHYS_TO_IO(x) (((x) & 0x00ffffff) | 0xfe000000) |
| 19 | #define PICOXCELL_PERIPH_BASE 0x80000000 | |
| 20 | #define PICOXCELL_PERIPH_LENGTH SZ_4M | |
| 21 | ||
| 22 | #define WDT_CTRL_REG_EN_MASK (1 << 0) | |
| 23 | #define WDT_CTRL_REG_OFFS (0x00) | |
| 24 | #define WDT_TIMEOUT_REG_OFFS (0x04) | |
| 1b46f878 JI |
25 | static void __iomem *wdt_regs; |
| 26 | ||
| 27 | /* | |
| 28 | * The machine restart method can be called from an atomic context so we won't | |
| 29 | * be able to ioremap the regs then. | |
| 30 | */ | |
| 31 | static void picoxcell_setup_restart(void) | |
| 32 | { | |
| 33 | struct device_node *np = of_find_compatible_node(NULL, NULL, | |
| 34 | "snps,dw-apb-wdg"); | |
| 35 | if (WARN(!np, "unable to setup watchdog restart")) | |
| 36 | return; | |
| 37 | ||
| 38 | wdt_regs = of_iomap(np, 0); | |
| 39 | WARN(!wdt_regs, "failed to remap watchdog regs"); | |
| 40 | } | |
| 41 | ||
| 8f37a0b4 JI |
42 | static struct map_desc io_map __initdata = { |
| 43 | .virtual = PHYS_TO_IO(PICOXCELL_PERIPH_BASE), | |
| 44 | .pfn = __phys_to_pfn(PICOXCELL_PERIPH_BASE), | |
| 45 | .length = PICOXCELL_PERIPH_LENGTH, | |
| 46 | .type = MT_DEVICE, | |
| 47 | }; | |
| 48 | ||
| 49 | static void __init picoxcell_map_io(void) | |
| 50 | { | |
| 51 | iotable_init(&io_map, 1); | |
| 52 | } | |
| 53 | ||
| af75655c JI |
54 | static void __init picoxcell_init_machine(void) |
| 55 | { | |
| 1b46f878 | 56 | picoxcell_setup_restart(); |
| af75655c JI |
57 | } |
| 58 | ||
| 59 | static const char *picoxcell_dt_match[] = { | |
| 60 | "picochip,pc3x2", | |
| 61 | "picochip,pc3x3", | |
| 62 | NULL | |
| 63 | }; | |
| 64 | ||
| 7b6d864b | 65 | static void picoxcell_wdt_restart(enum reboot_mode mode, const char *cmd) |
| 1b46f878 JI |
66 | { |
| 67 | /* | |
| 68 | * Configure the watchdog to reset with the shortest possible timeout | |
| 69 | * and give it chance to do the reset. | |
| 70 | */ | |
| 71 | if (wdt_regs) { | |
| 72 | writel_relaxed(WDT_CTRL_REG_EN_MASK, wdt_regs + WDT_CTRL_REG_OFFS); | |
| 73 | writel_relaxed(0, wdt_regs + WDT_TIMEOUT_REG_OFFS); | |
| 74 | /* No sleeping, possibly atomic. */ | |
| 75 | mdelay(500); | |
| 76 | } | |
| 77 | } | |
| 78 | ||
| af75655c JI |
79 | DT_MACHINE_START(PICOXCELL, "Picochip picoXcell") |
| 80 | .map_io = picoxcell_map_io, | |
| af75655c JI |
81 | .init_machine = picoxcell_init_machine, |
| 82 | .dt_compat = picoxcell_dt_match, | |
| 1b46f878 | 83 | .restart = picoxcell_wdt_restart, |
| af75655c | 84 | MACHINE_END |