forked from Minki/linux
bc34b5f27c
The Allwinner sun6i (A31) has a slightly different watchdog, that doesn't allow to use the already existing restart code. Rework a bit the restart code to allow to plug in more easily different restart handlers depending on the device tree. In the past, we were also meaning sunxi as a generic name covering all Allwinner SoCs. This won't be true anymore with the A31 (sun6i) that differs pretty much from sun4i and sun5i, and we will end up having sunxi, for sun4i and sun5i, and sun6i, which is neither consistent nor convenient. So, while we're at it, also change sunxi to sun4i. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
124 lines
2.9 KiB
C
124 lines
2.9 KiB
C
/*
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* Device Tree support for Allwinner A1X SoCs
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*
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* Copyright (C) 2012 Maxime Ripard
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*
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* Maxime Ripard <maxime.ripard@free-electrons.com>
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/clocksource.h>
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#include <linux/delay.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/irqchip.h>
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#include <linux/of_address.h>
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#include <linux/of_irq.h>
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#include <linux/of_platform.h>
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#include <linux/io.h>
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#include <linux/clk/sunxi.h>
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#include <asm/mach/arch.h>
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#include <asm/mach/map.h>
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#include <asm/system_misc.h>
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#include "sunxi.h"
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#define SUN4I_WATCHDOG_CTRL_REG 0x00
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#define SUN4I_WATCHDOG_CTRL_RESTART (1 << 0)
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#define SUN4I_WATCHDOG_MODE_REG 0x04
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#define SUN4I_WATCHDOG_MODE_ENABLE (1 << 0)
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#define SUN4I_WATCHDOG_MODE_RESET_ENABLE (1 << 1)
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static void __iomem *wdt_base;
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static void sun4i_restart(char mode, const char *cmd)
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{
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if (!wdt_base)
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return;
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/* Enable timer and set reset bit in the watchdog */
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writel(SUN4I_WATCHDOG_MODE_ENABLE | SUN4I_WATCHDOG_MODE_RESET_ENABLE,
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wdt_base + SUN4I_WATCHDOG_MODE_REG);
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/*
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* Restart the watchdog. The default (and lowest) interval
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* value for the watchdog is 0.5s.
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*/
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writel(SUN4I_WATCHDOG_CTRL_RESTART, wdt_base + SUN4I_WATCHDOG_CTRL_REG);
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while (1) {
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mdelay(5);
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writel(SUN4I_WATCHDOG_MODE_ENABLE | SUN4I_WATCHDOG_MODE_RESET_ENABLE,
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wdt_base + SUN4I_WATCHDOG_MODE_REG);
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}
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}
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static struct of_device_id sunxi_restart_ids[] = {
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{ .compatible = "allwinner,sun4i-wdt", .data = sun4i_restart },
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{ /*sentinel*/ }
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};
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static void sunxi_setup_restart(void)
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{
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const struct of_device_id *of_id;
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struct device_node *np;
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np = of_find_matching_node(NULL, sunxi_restart_ids);
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if (WARN(!np, "unable to setup watchdog restart"))
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return;
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wdt_base = of_iomap(np, 0);
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WARN(!wdt_base, "failed to map watchdog base address");
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of_id = of_match_node(sunxi_restart_ids, np);
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WARN(!of_id, "restart function not available");
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arm_pm_restart = of_id->data;
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}
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static struct map_desc sunxi_io_desc[] __initdata = {
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{
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.virtual = (unsigned long) SUNXI_REGS_VIRT_BASE,
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.pfn = __phys_to_pfn(SUNXI_REGS_PHYS_BASE),
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.length = SUNXI_REGS_SIZE,
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.type = MT_DEVICE,
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},
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};
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void __init sunxi_map_io(void)
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{
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iotable_init(sunxi_io_desc, ARRAY_SIZE(sunxi_io_desc));
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}
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static void __init sunxi_timer_init(void)
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{
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sunxi_init_clocks();
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clocksource_of_init();
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}
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static void __init sunxi_dt_init(void)
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{
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sunxi_setup_restart();
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of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
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}
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static const char * const sunxi_board_dt_compat[] = {
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"allwinner,sun4i-a10",
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"allwinner,sun5i-a13",
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NULL,
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};
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DT_MACHINE_START(SUNXI_DT, "Allwinner A1X (Device Tree)")
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.init_machine = sunxi_dt_init,
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.map_io = sunxi_map_io,
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.init_irq = irqchip_init,
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.init_time = sunxi_timer_init,
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.dt_compat = sunxi_board_dt_compat,
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MACHINE_END
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