arch/arm/mach-sunxi/sunxi.c

   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/clk-provider.h>
  14 #include <linux/clocksource.h>
  15 #include <linux/delay.h>
  16 #include <linux/kernel.h>
  17 #include <linux/init.h>
  18 #include <linux/of_address.h>
  19 #include <linux/of_irq.h>
  20 #include <linux/of_platform.h>
  21 #include <linux/io.h>
  22 #include <linux/reboot.h>
  23
  24 #include <asm/mach/arch.h>
  25 #include <asm/mach/map.h>
  26 #include <asm/system_misc.h>
  27
  28 #define SUN4I_WATCHDOG_CTRL_REG         0x00
  29 #define SUN4I_WATCHDOG_CTRL_RESTART             BIT(0)
  30 #define SUN4I_WATCHDOG_MODE_REG         0x04
  31 #define SUN4I_WATCHDOG_MODE_ENABLE              BIT(0)
  32 #define SUN4I_WATCHDOG_MODE_RESET_ENABLE        BIT(1)
  33
  34 #define SUN6I_WATCHDOG1_IRQ_REG         0x00
  35 #define SUN6I_WATCHDOG1_CTRL_REG        0x10
  36 #define SUN6I_WATCHDOG1_CTRL_RESTART            BIT(0)
  37 #define SUN6I_WATCHDOG1_CONFIG_REG      0x14
  38 #define SUN6I_WATCHDOG1_CONFIG_RESTART          BIT(0)
  39 #define SUN6I_WATCHDOG1_CONFIG_IRQ              BIT(1)
  40 #define SUN6I_WATCHDOG1_MODE_REG        0x18
  41 #define SUN6I_WATCHDOG1_MODE_ENABLE             BIT(0)
  42
  43 static void __iomem *wdt_base;
  44
  45 static void sun4i_restart(enum reboot_mode mode, const char *cmd)
  46 {
  47         if (!wdt_base)
  48                 return;
  49
  50         /* Enable timer and set reset bit in the watchdog */
  51         writel(SUN4I_WATCHDOG_MODE_ENABLE | SUN4I_WATCHDOG_MODE_RESET_ENABLE,
  52                wdt_base + SUN4I_WATCHDOG_MODE_REG);
  53
  54         /*
  55          * Restart the watchdog. The default (and lowest) interval
  56          * value for the watchdog is 0.5s.
  57          */
  58         writel(SUN4I_WATCHDOG_CTRL_RESTART, wdt_base + SUN4I_WATCHDOG_CTRL_REG);
  59
  60         while (1) {
  61                 mdelay(5);
  62                 writel(SUN4I_WATCHDOG_MODE_ENABLE | SUN4I_WATCHDOG_MODE_RESET_ENABLE,
  63                        wdt_base + SUN4I_WATCHDOG_MODE_REG);
  64         }
  65 }
  66
  67 static struct of_device_id sunxi_restart_ids[] = {
  68         { .compatible = "allwinner,sun4i-a10-wdt" },
  69         { /*sentinel*/ }
  70 };
  71
  72 static void sunxi_setup_restart(void)
  73 {
  74         struct device_node *np;
  75
  76         np = of_find_matching_node(NULL, sunxi_restart_ids);
  77         if (WARN(!np, "unable to setup watchdog restart"))
  78                 return;
  79
  80         wdt_base = of_iomap(np, 0);
  81         WARN(!wdt_base, "failed to map watchdog base address");
  82 }
  83
  84 static void __init sunxi_dt_init(void)
  85 {
  86         sunxi_setup_restart();
  87
  88         of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
  89 }
  90
  91 static const char * const sunxi_board_dt_compat[] = {
  92         "allwinner,sun4i-a10",
  93         "allwinner,sun5i-a10s",
  94         "allwinner,sun5i-a13",
  95         NULL,
  96 };
  97
  98 DT_MACHINE_START(SUNXI_DT, "Allwinner A1X (Device Tree)")
  99         .init_machine   = sunxi_dt_init,
 100         .dt_compat      = sunxi_board_dt_compat,
 101         .restart        = sun4i_restart,
 102 MACHINE_END
 103
 104 static const char * const sun6i_board_dt_compat[] = {
 105         "allwinner,sun6i-a31",
 106         NULL,
 107 };
 108
 109 extern void __init sun6i_reset_init(void);
 110 static void __init sun6i_timer_init(void)
 111 {
 112         of_clk_init(NULL);
 113         if (IS_ENABLED(CONFIG_RESET_CONTROLLER))
 114                 sun6i_reset_init();
 115         clocksource_of_init();
 116 }
 117
 118 DT_MACHINE_START(SUN6I_DT, "Allwinner sun6i (A31) Family")
 119         .init_time      = sun6i_timer_init,
 120         .dt_compat      = sun6i_board_dt_compat,
 121 MACHINE_END
 122
 123 static const char * const sun7i_board_dt_compat[] = {
 124         "allwinner,sun7i-a20",
 125         NULL,
 126 };
 127
 128 DT_MACHINE_START(SUN7I_DT, "Allwinner sun7i (A20) Family")
 129         .init_machine   = sunxi_dt_init,
 130         .dt_compat      = sun7i_board_dt_compat,
 131         .restart        = sun4i_restart,
 132 MACHINE_END