1 /* 2 * Device Tree support for Allwinner A1X SoCs 3 * 4 * Copyright (C) 2012 Maxime Ripard 5 * 6 * Maxime Ripard <maxime.ripard@free-electrons.com> 7 * 8 * This file is licensed under the terms of the GNU General Public 9 * License version 2. This program is licensed "as is" without any 10 * warranty of any kind, whether express or implied. 11 */ 12 13 #include <linux/delay.h> 14 #include <linux/kernel.h> 15 #include <linux/init.h> 16 #include <linux/of_address.h> 17 #include <linux/of_irq.h> 18 #include <linux/of_platform.h> 19 #include <linux/io.h> 20 #include <linux/sunxi_timer.h> 21 22 #include <linux/irqchip/sunxi.h> 23 24 #include <asm/hardware/vic.h> 25 26 #include <asm/mach/arch.h> 27 #include <asm/mach/map.h> 28 29 #include "sunxi.h" 30 31 #define WATCHDOG_CTRL_REG 0x00 32 #define WATCHDOG_MODE_REG 0x04 33 34 static void __iomem *wdt_base; 35 36 static void sunxi_setup_restart(void) 37 { 38 struct device_node *np = of_find_compatible_node(NULL, NULL, 39 "allwinner,sunxi-wdt"); 40 if (WARN(!np, "unable to setup watchdog restart")) 41 return; 42 43 wdt_base = of_iomap(np, 0); 44 WARN(!wdt_base, "failed to map watchdog base address"); 45 } 46 47 static void sunxi_restart(char mode, const char *cmd) 48 { 49 if (!wdt_base) 50 return; 51 52 /* Enable timer and set reset bit in the watchdog */ 53 writel(3, wdt_base + WATCHDOG_MODE_REG); 54 writel(0xa57 << 1 | 1, wdt_base + WATCHDOG_CTRL_REG); 55 while(1) { 56 mdelay(5); 57 writel(3, wdt_base + WATCHDOG_MODE_REG); 58 } 59 } 60 61 static struct map_desc sunxi_io_desc[] __initdata = { 62 { 63 .virtual = (unsigned long) SUNXI_REGS_VIRT_BASE, 64 .pfn = __phys_to_pfn(SUNXI_REGS_PHYS_BASE), 65 .length = SUNXI_REGS_SIZE, 66 .type = MT_DEVICE, 67 }, 68 }; 69 70 void __init sunxi_map_io(void) 71 { 72 iotable_init(sunxi_io_desc, ARRAY_SIZE(sunxi_io_desc)); 73 } 74 75 static void __init sunxi_dt_init(void) 76 { 77 sunxi_setup_restart(); 78 79 of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL); 80 } 81 82 static const char * const sunxi_board_dt_compat[] = { 83 "allwinner,sun4i", 84 "allwinner,sun5i", 85 NULL, 86 }; 87 88 DT_MACHINE_START(SUNXI_DT, "Allwinner A1X (Device Tree)") 89 .init_machine = sunxi_dt_init, 90 .map_io = sunxi_map_io, 91 .init_irq = sunxi_init_irq, 92 .handle_irq = sunxi_handle_irq, 93 .restart = sunxi_restart, 94 .timer = &sunxi_timer, 95 .dt_compat = sunxi_board_dt_compat, 96 MACHINE_END 97