// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2011 Picochip Ltd., Jamie Iles
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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/of.h>
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#include <linux/of_address.h>
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#include <linux/reboot.h>
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#include <asm/mach/arch.h>
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#include <asm/mach/map.h>
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#define PHYS_TO_IO(x) (((x) & 0x00ffffff) | 0xfe000000)
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#define PICOXCELL_PERIPH_BASE 0x80000000
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#define PICOXCELL_PERIPH_LENGTH SZ_4M
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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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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 void picoxcell_wdt_restart(enum reboot_mode 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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.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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