| /* |
| * Copyright (c) 2011 Picochip Ltd., Jamie Iles |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * All enquiries to support@picochip.com |
| */ |
| #include <linux/delay.h> |
| #include <linux/of.h> |
| #include <linux/of_address.h> |
| #include <linux/reboot.h> |
| |
| #include <asm/mach/arch.h> |
| #include <asm/mach/map.h> |
| |
| #define PHYS_TO_IO(x) (((x) & 0x00ffffff) | 0xfe000000) |
| #define PICOXCELL_PERIPH_BASE 0x80000000 |
| #define PICOXCELL_PERIPH_LENGTH SZ_4M |
| |
| #define WDT_CTRL_REG_EN_MASK (1 << 0) |
| #define WDT_CTRL_REG_OFFS (0x00) |
| #define WDT_TIMEOUT_REG_OFFS (0x04) |
| static void __iomem *wdt_regs; |
| |
| /* |
| * The machine restart method can be called from an atomic context so we won't |
| * be able to ioremap the regs then. |
| */ |
| static void picoxcell_setup_restart(void) |
| { |
| struct device_node *np = of_find_compatible_node(NULL, NULL, |
| "snps,dw-apb-wdg"); |
| if (WARN(!np, "unable to setup watchdog restart")) |
| return; |
| |
| wdt_regs = of_iomap(np, 0); |
| WARN(!wdt_regs, "failed to remap watchdog regs"); |
| } |
| |
| static struct map_desc io_map __initdata = { |
| .virtual = PHYS_TO_IO(PICOXCELL_PERIPH_BASE), |
| .pfn = __phys_to_pfn(PICOXCELL_PERIPH_BASE), |
| .length = PICOXCELL_PERIPH_LENGTH, |
| .type = MT_DEVICE, |
| }; |
| |
| static void __init picoxcell_map_io(void) |
| { |
| iotable_init(&io_map, 1); |
| } |
| |
| static void __init picoxcell_init_machine(void) |
| { |
| picoxcell_setup_restart(); |
| } |
| |
| static const char *picoxcell_dt_match[] = { |
| "picochip,pc3x2", |
| "picochip,pc3x3", |
| NULL |
| }; |
| |
| static void picoxcell_wdt_restart(enum reboot_mode mode, const char *cmd) |
| { |
| /* |
| * Configure the watchdog to reset with the shortest possible timeout |
| * and give it chance to do the reset. |
| */ |
| if (wdt_regs) { |
| writel_relaxed(WDT_CTRL_REG_EN_MASK, wdt_regs + WDT_CTRL_REG_OFFS); |
| writel_relaxed(0, wdt_regs + WDT_TIMEOUT_REG_OFFS); |
| /* No sleeping, possibly atomic. */ |
| mdelay(500); |
| } |
| } |
| |
| DT_MACHINE_START(PICOXCELL, "Picochip picoXcell") |
| .map_io = picoxcell_map_io, |
| .init_machine = picoxcell_init_machine, |
| .dt_compat = picoxcell_dt_match, |
| .restart = picoxcell_wdt_restart, |
| MACHINE_END |