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![Pratyush Anand](/assets/img/avatar_default.png)
/sys/class/watchdog/watchdogn/device/modalias can help to identify the driver/module for a given watchdog node. However, many wdt devices do not set their parent and so, we do not see an entry for device in sysfs for such devices. This patch fixes parent of watchdog_device so that /sys/class/watchdog/watchdogn/device is populated. Exceptions: booke, diag288, octeon, softdog and w83627hf -- They do not have any parent. Not sure, how we can identify driver for these devices. Signed-off-by: Pratyush Anand <panand@redhat.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Guenter Roeck <linux@roeck-us.net> Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com> Acked-by: Lee Jones <lee.jones@linaro.org> Acked-by: Lubomir Rintel <lkundrak@v3.sk> Acked-by: Maxime Coquelin <maxime.coquelin@st.com> Acked-by: Thierry Reding <treding@nvidia.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
345 lines
8 KiB
C
345 lines
8 KiB
C
/*
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* ST's LPC Watchdog
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*
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* Copyright (C) 2014 STMicroelectronics -- All Rights Reserved
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*
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* Author: David Paris <david.paris@st.com> for STMicroelectronics
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* Lee Jones <lee.jones@linaro.org> for STMicroelectronics
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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*/
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#include <linux/clk.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/mfd/syscon.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_platform.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <linux/watchdog.h>
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#include <dt-bindings/mfd/st-lpc.h>
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/* Low Power Alarm */
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#define LPC_LPA_LSB_OFF 0x410
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#define LPC_LPA_START_OFF 0x418
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/* LPC as WDT */
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#define LPC_WDT_OFF 0x510
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static struct watchdog_device st_wdog_dev;
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struct st_wdog_syscfg {
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unsigned int reset_type_reg;
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unsigned int reset_type_mask;
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unsigned int enable_reg;
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unsigned int enable_mask;
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};
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struct st_wdog {
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void __iomem *base;
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struct device *dev;
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struct regmap *regmap;
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struct st_wdog_syscfg *syscfg;
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struct clk *clk;
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unsigned long clkrate;
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bool warm_reset;
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};
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static struct st_wdog_syscfg stid127_syscfg = {
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.reset_type_reg = 0x004,
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.reset_type_mask = BIT(2),
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.enable_reg = 0x000,
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.enable_mask = BIT(2),
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};
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static struct st_wdog_syscfg stih415_syscfg = {
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.reset_type_reg = 0x0B8,
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.reset_type_mask = BIT(6),
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.enable_reg = 0x0B4,
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.enable_mask = BIT(7),
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};
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static struct st_wdog_syscfg stih416_syscfg = {
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.reset_type_reg = 0x88C,
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.reset_type_mask = BIT(6),
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.enable_reg = 0x888,
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.enable_mask = BIT(7),
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};
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static struct st_wdog_syscfg stih407_syscfg = {
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.enable_reg = 0x204,
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.enable_mask = BIT(19),
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};
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static const struct of_device_id st_wdog_match[] = {
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{
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.compatible = "st,stih407-lpc",
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.data = &stih407_syscfg,
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},
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{
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.compatible = "st,stih416-lpc",
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.data = &stih416_syscfg,
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},
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{
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.compatible = "st,stih415-lpc",
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.data = &stih415_syscfg,
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},
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{
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.compatible = "st,stid127-lpc",
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.data = &stid127_syscfg,
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},
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{},
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};
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MODULE_DEVICE_TABLE(of, st_wdog_match);
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static void st_wdog_setup(struct st_wdog *st_wdog, bool enable)
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{
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/* Type of watchdog reset - 0: Cold 1: Warm */
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if (st_wdog->syscfg->reset_type_reg)
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regmap_update_bits(st_wdog->regmap,
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st_wdog->syscfg->reset_type_reg,
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st_wdog->syscfg->reset_type_mask,
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st_wdog->warm_reset);
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/* Mask/unmask watchdog reset */
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regmap_update_bits(st_wdog->regmap,
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st_wdog->syscfg->enable_reg,
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st_wdog->syscfg->enable_mask,
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enable ? 0 : st_wdog->syscfg->enable_mask);
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}
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static void st_wdog_load_timer(struct st_wdog *st_wdog, unsigned int timeout)
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{
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unsigned long clkrate = st_wdog->clkrate;
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writel_relaxed(timeout * clkrate, st_wdog->base + LPC_LPA_LSB_OFF);
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writel_relaxed(1, st_wdog->base + LPC_LPA_START_OFF);
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}
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static int st_wdog_start(struct watchdog_device *wdd)
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{
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struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
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writel_relaxed(1, st_wdog->base + LPC_WDT_OFF);
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return 0;
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}
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static int st_wdog_stop(struct watchdog_device *wdd)
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{
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struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
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writel_relaxed(0, st_wdog->base + LPC_WDT_OFF);
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return 0;
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}
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static int st_wdog_set_timeout(struct watchdog_device *wdd,
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unsigned int timeout)
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{
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struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
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wdd->timeout = timeout;
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st_wdog_load_timer(st_wdog, timeout);
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return 0;
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}
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static int st_wdog_keepalive(struct watchdog_device *wdd)
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{
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struct st_wdog *st_wdog = watchdog_get_drvdata(wdd);
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st_wdog_load_timer(st_wdog, wdd->timeout);
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return 0;
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}
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static const struct watchdog_info st_wdog_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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.identity = "ST LPC WDT",
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};
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static const struct watchdog_ops st_wdog_ops = {
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.owner = THIS_MODULE,
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.start = st_wdog_start,
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.stop = st_wdog_stop,
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.ping = st_wdog_keepalive,
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.set_timeout = st_wdog_set_timeout,
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};
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static struct watchdog_device st_wdog_dev = {
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.info = &st_wdog_info,
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.ops = &st_wdog_ops,
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};
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static int st_wdog_probe(struct platform_device *pdev)
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{
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const struct of_device_id *match;
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struct device_node *np = pdev->dev.of_node;
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struct st_wdog *st_wdog;
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struct regmap *regmap;
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struct resource *res;
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struct clk *clk;
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void __iomem *base;
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uint32_t mode;
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int ret;
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ret = of_property_read_u32(np, "st,lpc-mode", &mode);
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if (ret) {
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dev_err(&pdev->dev, "An LPC mode must be provided\n");
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return -EINVAL;
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}
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/* LPC can either run as a Clocksource or in RTC or WDT mode */
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if (mode != ST_LPC_MODE_WDT)
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return -ENODEV;
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st_wdog = devm_kzalloc(&pdev->dev, sizeof(*st_wdog), GFP_KERNEL);
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if (!st_wdog)
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return -ENOMEM;
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match = of_match_device(st_wdog_match, &pdev->dev);
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if (!match) {
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dev_err(&pdev->dev, "Couldn't match device\n");
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return -ENODEV;
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}
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st_wdog->syscfg = (struct st_wdog_syscfg *)match->data;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(base))
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return PTR_ERR(base);
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regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
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if (IS_ERR(regmap)) {
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dev_err(&pdev->dev, "No syscfg phandle specified\n");
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return PTR_ERR(regmap);
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}
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clk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(clk)) {
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dev_err(&pdev->dev, "Unable to request clock\n");
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return PTR_ERR(clk);
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}
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st_wdog->dev = &pdev->dev;
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st_wdog->base = base;
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st_wdog->clk = clk;
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st_wdog->regmap = regmap;
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st_wdog->warm_reset = of_property_read_bool(np, "st,warm_reset");
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st_wdog->clkrate = clk_get_rate(st_wdog->clk);
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if (!st_wdog->clkrate) {
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dev_err(&pdev->dev, "Unable to fetch clock rate\n");
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return -EINVAL;
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}
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st_wdog_dev.max_timeout = 0xFFFFFFFF / st_wdog->clkrate;
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st_wdog_dev.parent = &pdev->dev;
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ret = clk_prepare_enable(clk);
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if (ret) {
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dev_err(&pdev->dev, "Unable to enable clock\n");
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return ret;
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}
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watchdog_set_drvdata(&st_wdog_dev, st_wdog);
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watchdog_set_nowayout(&st_wdog_dev, WATCHDOG_NOWAYOUT);
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/* Init Watchdog timeout with value in DT */
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ret = watchdog_init_timeout(&st_wdog_dev, 0, &pdev->dev);
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if (ret) {
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dev_err(&pdev->dev, "Unable to initialise watchdog timeout\n");
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clk_disable_unprepare(clk);
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return ret;
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}
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ret = watchdog_register_device(&st_wdog_dev);
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if (ret) {
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dev_err(&pdev->dev, "Unable to register watchdog\n");
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clk_disable_unprepare(clk);
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return ret;
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}
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st_wdog_setup(st_wdog, true);
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dev_info(&pdev->dev, "LPC Watchdog driver registered, reset type is %s",
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st_wdog->warm_reset ? "warm" : "cold");
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return ret;
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}
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static int st_wdog_remove(struct platform_device *pdev)
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{
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struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev);
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st_wdog_setup(st_wdog, false);
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watchdog_unregister_device(&st_wdog_dev);
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clk_disable_unprepare(st_wdog->clk);
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int st_wdog_suspend(struct device *dev)
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{
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struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev);
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if (watchdog_active(&st_wdog_dev))
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st_wdog_stop(&st_wdog_dev);
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st_wdog_setup(st_wdog, false);
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clk_disable(st_wdog->clk);
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return 0;
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}
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static int st_wdog_resume(struct device *dev)
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{
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struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev);
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int ret;
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ret = clk_enable(st_wdog->clk);
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if (ret) {
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dev_err(dev, "Unable to re-enable clock\n");
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watchdog_unregister_device(&st_wdog_dev);
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clk_unprepare(st_wdog->clk);
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return ret;
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}
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st_wdog_setup(st_wdog, true);
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if (watchdog_active(&st_wdog_dev)) {
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st_wdog_load_timer(st_wdog, st_wdog_dev.timeout);
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st_wdog_start(&st_wdog_dev);
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}
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return 0;
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}
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#endif
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static SIMPLE_DEV_PM_OPS(st_wdog_pm_ops,
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st_wdog_suspend,
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st_wdog_resume);
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static struct platform_driver st_wdog_driver = {
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.driver = {
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.name = "st-lpc-wdt",
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.pm = &st_wdog_pm_ops,
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.of_match_table = st_wdog_match,
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},
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.probe = st_wdog_probe,
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.remove = st_wdog_remove,
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};
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module_platform_driver(st_wdog_driver);
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MODULE_AUTHOR("David Paris <david.paris@st.com>");
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MODULE_DESCRIPTION("ST LPC Watchdog Driver");
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MODULE_LICENSE("GPL");
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