1 // SPDX-License-Identifier: GPL-2.0-only OR MIT
3  * Apple SoC Watchdog driver
17 #include <linux/watchdog.h>
20  * Apple Watchdog MMIO registers
71 	writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CUR_TIME);  in apple_wdt_start()
72 	writel_relaxed(APPLE_WDT_CTRL_RESET_EN, wdt->regs + APPLE_WDT_WD1_CTRL);  in apple_wdt_start()
81 	writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CTRL);  in apple_wdt_stop()
90 	writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CUR_TIME);  in apple_wdt_ping()
99 	writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CUR_TIME);  in apple_wdt_set_timeout()
100 	writel_relaxed(wdt->clk_rate * s, wdt->regs + APPLE_WDT_WD1_BITE_TIME);  in apple_wdt_set_timeout()
102 	wdd->timeout = s;  in apple_wdt_set_timeout()
112 	cur_time = readl_relaxed(wdt->regs + APPLE_WDT_WD1_CUR_TIME);  in apple_wdt_get_timeleft()
113 	reset_time = readl_relaxed(wdt->regs + APPLE_WDT_WD1_BITE_TIME);  in apple_wdt_get_timeleft()
115 	return (reset_time - cur_time) / wdt->clk_rate;  in apple_wdt_get_timeleft()
123 	writel_relaxed(APPLE_WDT_CTRL_RESET_EN, wdt->regs + APPLE_WDT_WD1_CTRL);  in apple_wdt_restart()
124 	writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_BITE_TIME);  in apple_wdt_restart()
125 	writel_relaxed(0, wdt->regs + APPLE_WDT_WD1_CUR_TIME);  in apple_wdt_restart()
130 	 * can take up to ~20-25ms until the SoC is actually reset. Just wait  in apple_wdt_restart()
131 	 * 50ms here to be safe.  in apple_wdt_restart()
133 	(void)readl(wdt->regs + APPLE_WDT_WD1_CUR_TIME);  in apple_wdt_restart()
150 	.identity = "Apple SoC Watchdog",
156 	struct device *dev = &pdev->dev;  in apple_wdt_probe()
163 		return -ENOMEM;  in apple_wdt_probe()
165 	wdt->regs = devm_platform_ioremap_resource(pdev, 0);  in apple_wdt_probe()
166 	if (IS_ERR(wdt->regs))  in apple_wdt_probe()
167 		return PTR_ERR(wdt->regs);  in apple_wdt_probe()
172 	wdt->clk_rate = clk_get_rate(clk);  in apple_wdt_probe()
173 	if (!wdt->clk_rate)  in apple_wdt_probe()
174 		return -EINVAL;  in apple_wdt_probe()
176 	wdt->wdd.ops = &apple_wdt_ops;  in apple_wdt_probe()
177 	wdt->wdd.info = &apple_wdt_info;  in apple_wdt_probe()
178 	wdt->wdd.max_timeout = U32_MAX / wdt->clk_rate;  in apple_wdt_probe()
179 	wdt->wdd.timeout = APPLE_WDT_TIMEOUT_DEFAULT;  in apple_wdt_probe()
181 	wdt_ctrl = readl_relaxed(wdt->regs + APPLE_WDT_WD1_CTRL);  in apple_wdt_probe()
183 		set_bit(WDOG_HW_RUNNING, &wdt->wdd.status);  in apple_wdt_probe()
185 	watchdog_init_timeout(&wdt->wdd, 0, dev);  in apple_wdt_probe()
186 	apple_wdt_set_timeout(&wdt->wdd, wdt->wdd.timeout);  in apple_wdt_probe()
187 	watchdog_stop_on_unregister(&wdt->wdd);  in apple_wdt_probe()
188 	watchdog_set_restart_priority(&wdt->wdd, 128);  in apple_wdt_probe()
190 	return devm_watchdog_register_device(dev, &wdt->wdd);  in apple_wdt_probe()
201 		.name = "apple-watchdog",
208 MODULE_DESCRIPTION("Apple SoC watchdog driver");