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b89a9c400b
In order to prepare to support multiple compatible-strings, this commit adds a device structure to hold the driver's state. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> Tested-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Acked-by: Wim Van Sebroeck <wim@iguana.be> Tested-By: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Signed-off-by: Jason Cooper <jason@lakedaemon.net>
303 lines
7.7 KiB
C
303 lines
7.7 KiB
C
/*
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* drivers/watchdog/orion_wdt.c
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*
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* Watchdog driver for Orion/Kirkwood processors
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*
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* Author: Sylver Bruneau <sylver.bruneau@googlemail.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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/platform_device.h>
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#include <linux/watchdog.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/of.h>
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/* RSTOUT mask register physical address for Orion5x, Kirkwood and Dove */
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#define ORION_RSTOUT_MASK_OFFSET 0x20108
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/* Internal registers can be configured at any 1 MiB aligned address */
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#define INTERNAL_REGS_MASK ~(SZ_1M - 1)
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/*
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* Watchdog timer block registers.
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*/
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#define TIMER_CTRL 0x0000
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#define WDT_EN 0x0010
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#define WDT_VAL 0x0024
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#define WDT_MAX_CYCLE_COUNT 0xffffffff
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#define WDT_RESET_OUT_EN BIT(1)
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static bool nowayout = WATCHDOG_NOWAYOUT;
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static int heartbeat = -1; /* module parameter (seconds) */
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struct orion_watchdog {
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struct watchdog_device wdt;
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void __iomem *reg;
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void __iomem *rstout;
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unsigned long clk_rate;
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struct clk *clk;
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};
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static int orion_wdt_ping(struct watchdog_device *wdt_dev)
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{
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struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
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/* Reload watchdog duration */
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writel(dev->clk_rate * wdt_dev->timeout, dev->reg + WDT_VAL);
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return 0;
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}
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static int orion_wdt_start(struct watchdog_device *wdt_dev)
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{
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struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
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/* Set watchdog duration */
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writel(dev->clk_rate * wdt_dev->timeout, dev->reg + WDT_VAL);
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/* Enable watchdog timer */
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atomic_io_modify(dev->reg + TIMER_CTRL, WDT_EN, WDT_EN);
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/* Enable reset on watchdog */
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atomic_io_modify(dev->rstout, WDT_RESET_OUT_EN, WDT_RESET_OUT_EN);
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return 0;
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}
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static int orion_wdt_stop(struct watchdog_device *wdt_dev)
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{
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struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
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/* Disable reset on watchdog */
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atomic_io_modify(dev->rstout, WDT_RESET_OUT_EN, 0);
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/* Disable watchdog timer */
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atomic_io_modify(dev->reg + TIMER_CTRL, WDT_EN, 0);
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return 0;
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}
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static int orion_wdt_enabled(struct orion_watchdog *dev)
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{
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bool enabled, running;
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enabled = readl(dev->rstout) & WDT_RESET_OUT_EN;
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running = readl(dev->reg + TIMER_CTRL) & WDT_EN;
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return enabled && running;
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}
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static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
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{
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struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
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return readl(dev->reg + WDT_VAL) / dev->clk_rate;
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}
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static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev,
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unsigned int timeout)
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{
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wdt_dev->timeout = timeout;
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return 0;
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}
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static const struct watchdog_info orion_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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.identity = "Orion Watchdog",
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};
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static const struct watchdog_ops orion_wdt_ops = {
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.owner = THIS_MODULE,
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.start = orion_wdt_start,
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.stop = orion_wdt_stop,
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.ping = orion_wdt_ping,
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.set_timeout = orion_wdt_set_timeout,
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.get_timeleft = orion_wdt_get_timeleft,
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};
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static irqreturn_t orion_wdt_irq(int irq, void *devid)
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{
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panic("Watchdog Timeout");
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return IRQ_HANDLED;
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}
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/*
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* The original devicetree binding for this driver specified only
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* one memory resource, so in order to keep DT backwards compatibility
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* we try to fallback to a hardcoded register address, if the resource
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* is missing from the devicetree.
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*/
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static void __iomem *orion_wdt_ioremap_rstout(struct platform_device *pdev,
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phys_addr_t internal_regs)
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{
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struct resource *res;
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phys_addr_t rstout;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
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if (res)
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return devm_ioremap(&pdev->dev, res->start,
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resource_size(res));
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/* This workaround works only for "orion-wdt", DT-enabled */
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if (!of_device_is_compatible(pdev->dev.of_node, "marvell,orion-wdt"))
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return NULL;
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rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET;
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WARN(1, FW_BUG "falling back to harcoded RSTOUT reg 0x%x\n", rstout);
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return devm_ioremap(&pdev->dev, rstout, 0x4);
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}
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static int orion_wdt_probe(struct platform_device *pdev)
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{
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struct orion_watchdog *dev;
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unsigned int wdt_max_duration; /* (seconds) */
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struct resource *res;
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int ret, irq;
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dev = devm_kzalloc(&pdev->dev, sizeof(struct orion_watchdog),
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GFP_KERNEL);
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if (!dev)
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return -ENOMEM;
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dev->wdt.info = &orion_wdt_info;
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dev->wdt.ops = &orion_wdt_ops;
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dev->wdt.min_timeout = 1;
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dev->clk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(dev->clk)) {
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dev_err(&pdev->dev, "Orion Watchdog missing clock\n");
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return PTR_ERR(dev->clk);
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}
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ret = clk_prepare_enable(dev->clk);
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if (ret)
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return ret;
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dev->clk_rate = clk_get_rate(dev->clk);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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ret = -ENODEV;
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goto disable_clk;
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}
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dev->reg = devm_ioremap(&pdev->dev, res->start,
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resource_size(res));
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if (!dev->reg) {
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ret = -ENOMEM;
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goto disable_clk;
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}
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dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start &
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INTERNAL_REGS_MASK);
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if (!dev->rstout) {
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ret = -ENODEV;
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goto disable_clk;
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}
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wdt_max_duration = WDT_MAX_CYCLE_COUNT / dev->clk_rate;
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dev->wdt.timeout = wdt_max_duration;
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dev->wdt.max_timeout = wdt_max_duration;
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watchdog_init_timeout(&dev->wdt, heartbeat, &pdev->dev);
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platform_set_drvdata(pdev, &dev->wdt);
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watchdog_set_drvdata(&dev->wdt, dev);
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/*
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* Let's make sure the watchdog is fully stopped, unless it's
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* explicitly enabled. This may be the case if the module was
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* removed and re-insterted, or if the bootloader explicitly
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* set a running watchdog before booting the kernel.
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*/
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if (!orion_wdt_enabled(dev))
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orion_wdt_stop(&dev->wdt);
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/* Request the IRQ only after the watchdog is disabled */
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irq = platform_get_irq(pdev, 0);
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if (irq > 0) {
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/*
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* Not all supported platforms specify an interrupt for the
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* watchdog, so let's make it optional.
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*/
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ret = devm_request_irq(&pdev->dev, irq, orion_wdt_irq, 0,
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pdev->name, dev);
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if (ret < 0) {
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dev_err(&pdev->dev, "failed to request IRQ\n");
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goto disable_clk;
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}
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}
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watchdog_set_nowayout(&dev->wdt, nowayout);
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ret = watchdog_register_device(&dev->wdt);
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if (ret)
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goto disable_clk;
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pr_info("Initial timeout %d sec%s\n",
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dev->wdt.timeout, nowayout ? ", nowayout" : "");
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return 0;
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disable_clk:
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clk_disable_unprepare(dev->clk);
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return ret;
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}
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static int orion_wdt_remove(struct platform_device *pdev)
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{
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struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
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struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
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watchdog_unregister_device(wdt_dev);
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clk_disable_unprepare(dev->clk);
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return 0;
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}
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static void orion_wdt_shutdown(struct platform_device *pdev)
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{
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struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
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orion_wdt_stop(wdt_dev);
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}
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static const struct of_device_id orion_wdt_of_match_table[] = {
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{ .compatible = "marvell,orion-wdt", },
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{},
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};
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MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
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static struct platform_driver orion_wdt_driver = {
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.probe = orion_wdt_probe,
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.remove = orion_wdt_remove,
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.shutdown = orion_wdt_shutdown,
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.driver = {
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.owner = THIS_MODULE,
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.name = "orion_wdt",
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.of_match_table = orion_wdt_of_match_table,
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},
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};
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module_platform_driver(orion_wdt_driver);
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MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
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MODULE_DESCRIPTION("Orion Processor Watchdog");
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module_param(heartbeat, int, 0);
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MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:orion_wdt");
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