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1b46f8782c
Allow the platform to be restarted by triggering the watchdog to expire with the shortest possible expiry. This should reset the CPU core and all on-chip peripherals. v2: - use writel_relaxed(). Signed-off-by: Jamie Iles <jamie@jamieiles.com>
105 lines
2.6 KiB
C
105 lines
2.6 KiB
C
/*
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* Copyright (c) 2011 Picochip Ltd., Jamie Iles
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* All enquiries to support@picochip.com
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*/
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#include <linux/delay.h>
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#include <linux/irq.h>
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#include <linux/irqdomain.h>
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#include <linux/of.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 <asm/mach/arch.h>
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#include <asm/hardware/vic.h>
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#include <asm/mach/map.h>
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#include <mach/map.h>
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#include <mach/picoxcell_soc.h>
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#include "common.h"
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#define WDT_CTRL_REG_EN_MASK (1 << 0)
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#define WDT_CTRL_REG_OFFS (0x00)
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#define WDT_TIMEOUT_REG_OFFS (0x04)
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static void __iomem *wdt_regs;
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/*
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* The machine restart method can be called from an atomic context so we won't
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* be able to ioremap the regs then.
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*/
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static void picoxcell_setup_restart(void)
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{
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struct device_node *np = of_find_compatible_node(NULL, NULL,
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"snps,dw-apb-wdg");
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if (WARN(!np, "unable to setup watchdog restart"))
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return;
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wdt_regs = of_iomap(np, 0);
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WARN(!wdt_regs, "failed to remap watchdog regs");
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}
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static struct map_desc io_map __initdata = {
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.virtual = PHYS_TO_IO(PICOXCELL_PERIPH_BASE),
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.pfn = __phys_to_pfn(PICOXCELL_PERIPH_BASE),
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.length = PICOXCELL_PERIPH_LENGTH,
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.type = MT_DEVICE,
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};
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static void __init picoxcell_map_io(void)
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{
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iotable_init(&io_map, 1);
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}
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static void __init picoxcell_init_machine(void)
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{
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of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
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picoxcell_setup_restart();
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}
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static const char *picoxcell_dt_match[] = {
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"picochip,pc3x2",
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"picochip,pc3x3",
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NULL
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};
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static const struct of_device_id vic_of_match[] __initconst = {
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{ .compatible = "arm,pl192-vic", .data = vic_of_init, },
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{ /* Sentinel */ }
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};
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static void __init picoxcell_init_irq(void)
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{
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of_irq_init(vic_of_match);
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}
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static void picoxcell_wdt_restart(char mode, const char *cmd)
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{
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/*
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* Configure the watchdog to reset with the shortest possible timeout
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* and give it chance to do the reset.
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*/
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if (wdt_regs) {
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writel_relaxed(WDT_CTRL_REG_EN_MASK, wdt_regs + WDT_CTRL_REG_OFFS);
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writel_relaxed(0, wdt_regs + WDT_TIMEOUT_REG_OFFS);
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/* No sleeping, possibly atomic. */
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mdelay(500);
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}
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}
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DT_MACHINE_START(PICOXCELL, "Picochip picoXcell")
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.map_io = picoxcell_map_io,
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.nr_irqs = NR_IRQS_LEGACY,
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.init_irq = picoxcell_init_irq,
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.handle_irq = vic_handle_irq,
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.timer = &picoxcell_timer,
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.init_machine = picoxcell_init_machine,
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.dt_compat = picoxcell_dt_match,
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.restart = picoxcell_wdt_restart,
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MACHINE_END
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