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163 lines
3.8 KiB
163 lines
3.8 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* Watchdog driver for Conexant Digicolor |
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* |
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* Copyright (C) 2015 Paradox Innovation Ltd. |
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* |
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*/ |
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#include <linux/types.h> |
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#include <linux/module.h> |
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#include <linux/io.h> |
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#include <linux/delay.h> |
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#include <linux/clk.h> |
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#include <linux/watchdog.h> |
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#include <linux/platform_device.h> |
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#include <linux/of_address.h> |
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#define TIMER_A_CONTROL 0 |
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#define TIMER_A_COUNT 4 |
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#define TIMER_A_ENABLE_COUNT BIT(0) |
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#define TIMER_A_ENABLE_WATCHDOG BIT(1) |
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struct dc_wdt { |
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void __iomem *base; |
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struct clk *clk; |
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spinlock_t lock; |
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}; |
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static unsigned timeout; |
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module_param(timeout, uint, 0); |
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MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds"); |
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static void dc_wdt_set(struct dc_wdt *wdt, u32 ticks) |
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{ |
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unsigned long flags; |
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spin_lock_irqsave(&wdt->lock, flags); |
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writel_relaxed(0, wdt->base + TIMER_A_CONTROL); |
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writel_relaxed(ticks, wdt->base + TIMER_A_COUNT); |
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writel_relaxed(TIMER_A_ENABLE_COUNT | TIMER_A_ENABLE_WATCHDOG, |
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wdt->base + TIMER_A_CONTROL); |
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spin_unlock_irqrestore(&wdt->lock, flags); |
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} |
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static int dc_wdt_restart(struct watchdog_device *wdog, unsigned long action, |
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void *data) |
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{ |
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struct dc_wdt *wdt = watchdog_get_drvdata(wdog); |
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dc_wdt_set(wdt, 1); |
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/* wait for reset to assert... */ |
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mdelay(500); |
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return 0; |
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} |
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static int dc_wdt_start(struct watchdog_device *wdog) |
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{ |
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struct dc_wdt *wdt = watchdog_get_drvdata(wdog); |
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dc_wdt_set(wdt, wdog->timeout * clk_get_rate(wdt->clk)); |
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return 0; |
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} |
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static int dc_wdt_stop(struct watchdog_device *wdog) |
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{ |
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struct dc_wdt *wdt = watchdog_get_drvdata(wdog); |
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writel_relaxed(0, wdt->base + TIMER_A_CONTROL); |
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return 0; |
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} |
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static int dc_wdt_set_timeout(struct watchdog_device *wdog, unsigned int t) |
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{ |
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struct dc_wdt *wdt = watchdog_get_drvdata(wdog); |
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dc_wdt_set(wdt, t * clk_get_rate(wdt->clk)); |
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wdog->timeout = t; |
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return 0; |
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} |
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static unsigned int dc_wdt_get_timeleft(struct watchdog_device *wdog) |
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{ |
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struct dc_wdt *wdt = watchdog_get_drvdata(wdog); |
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uint32_t count = readl_relaxed(wdt->base + TIMER_A_COUNT); |
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return count / clk_get_rate(wdt->clk); |
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} |
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static const struct watchdog_ops dc_wdt_ops = { |
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.owner = THIS_MODULE, |
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.start = dc_wdt_start, |
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.stop = dc_wdt_stop, |
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.set_timeout = dc_wdt_set_timeout, |
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.get_timeleft = dc_wdt_get_timeleft, |
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.restart = dc_wdt_restart, |
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}; |
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static const struct watchdog_info dc_wdt_info = { |
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.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE |
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| WDIOF_KEEPALIVEPING, |
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.identity = "Conexant Digicolor Watchdog", |
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}; |
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static struct watchdog_device dc_wdt_wdd = { |
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.info = &dc_wdt_info, |
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.ops = &dc_wdt_ops, |
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.min_timeout = 1, |
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}; |
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static int dc_wdt_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct dc_wdt *wdt; |
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wdt = devm_kzalloc(dev, sizeof(struct dc_wdt), GFP_KERNEL); |
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if (!wdt) |
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return -ENOMEM; |
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wdt->base = devm_platform_ioremap_resource(pdev, 0); |
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if (IS_ERR(wdt->base)) |
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return PTR_ERR(wdt->base); |
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wdt->clk = devm_clk_get(dev, NULL); |
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if (IS_ERR(wdt->clk)) |
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return PTR_ERR(wdt->clk); |
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dc_wdt_wdd.max_timeout = U32_MAX / clk_get_rate(wdt->clk); |
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dc_wdt_wdd.timeout = dc_wdt_wdd.max_timeout; |
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dc_wdt_wdd.parent = dev; |
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spin_lock_init(&wdt->lock); |
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watchdog_set_drvdata(&dc_wdt_wdd, wdt); |
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watchdog_set_restart_priority(&dc_wdt_wdd, 128); |
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watchdog_init_timeout(&dc_wdt_wdd, timeout, dev); |
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watchdog_stop_on_reboot(&dc_wdt_wdd); |
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return devm_watchdog_register_device(dev, &dc_wdt_wdd); |
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} |
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static const struct of_device_id dc_wdt_of_match[] = { |
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{ .compatible = "cnxt,cx92755-wdt", }, |
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{}, |
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}; |
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MODULE_DEVICE_TABLE(of, dc_wdt_of_match); |
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static struct platform_driver dc_wdt_driver = { |
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.probe = dc_wdt_probe, |
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.driver = { |
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.name = "digicolor-wdt", |
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.of_match_table = dc_wdt_of_match, |
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}, |
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}; |
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module_platform_driver(dc_wdt_driver); |
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MODULE_AUTHOR("Baruch Siach <[email protected]>"); |
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MODULE_DESCRIPTION("Driver for Conexant Digicolor watchdog timer"); |
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MODULE_LICENSE("GPL");
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