/* * 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