1 // SPDX-License-Identifier: GPL-2.0
3  * Watchdog driver for the K3 RTI module
5  * (c) Copyright 2019-2020 Texas Instruments Inc.
58  * struct to hold data for each WDT device
59  * @base - base io address of WD device
60  * @freq - source clock frequency of WDT
61  * @wdd  - hold watchdog device as is in WDT core
72 	struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd);  in rti_wdt_start()  local
75 	timer_margin = (u64)wdd->timeout * wdt->freq;  in rti_wdt_start()
79 	writel_relaxed(timer_margin, wdt->base + RTIDWDPRLD);  in rti_wdt_start()
82 	 * RTI only supports a windowed mode, where the watchdog can only  in rti_wdt_start()
88 	wdd->min_hw_heartbeat_ms = 500 * wdd->timeout;  in rti_wdt_start()
90 	/* Generate NMI when wdt expires */  in rti_wdt_start()
91 	writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL);  in rti_wdt_start()
94 	writel_relaxed(RTIWWDSIZE_50P, wdt->base + RTIWWDSIZECTRL);  in rti_wdt_start()
96 	readl_relaxed(wdt->base + RTIWWDSIZECTRL);  in rti_wdt_start()
99 	writel_relaxed(WDENABLE_KEY, wdt->base + RTIDWDCTRL);  in rti_wdt_start()
105 	struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd);  in rti_wdt_ping()  local
108 	writel_relaxed(WDKEY_SEQ0, wdt->base + RTIWDKEY);  in rti_wdt_ping()
110 	writel_relaxed(WDKEY_SEQ1, wdt->base + RTIWDKEY);  in rti_wdt_ping()
118 	 * RTI only supports a windowed mode, where the watchdog can only  in rti_wdt_setup_hw_hb()
126 		wdd->min_hw_heartbeat_ms = 500 * heartbeat;  in rti_wdt_setup_hw_hb()
131 		wdd->min_hw_heartbeat_ms = 750 * heartbeat;  in rti_wdt_setup_hw_hb()
136 		wdd->min_hw_heartbeat_ms = 875 * heartbeat;  in rti_wdt_setup_hw_hb()
141 		wdd->min_hw_heartbeat_ms = 935 * heartbeat;  in rti_wdt_setup_hw_hb()
146 		wdd->min_hw_heartbeat_ms = 969 * heartbeat;  in rti_wdt_setup_hw_hb()
150 		return -EINVAL;  in rti_wdt_setup_hw_hb()
160 	struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd);  in rti_wdt_get_timeleft_ms()  local
163 	val = readl_relaxed(wdt->base + RTIWDSTATUS);  in rti_wdt_get_timeleft_ms()
167 	timer_counter = readl_relaxed(wdt->base + RTIDWDCNTR);  in rti_wdt_get_timeleft_ms()
171 	do_div(timer_counter, wdt->freq);  in rti_wdt_get_timeleft_ms()
183 	.identity = "K3 RTI Watchdog",
196 	struct device *dev = &pdev->dev;  in rti_wdt_probe()
198 	struct rti_wdt_device *wdt;  in rti_wdt_probe()  local
202 	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);  in rti_wdt_probe()
203 	if (!wdt)  in rti_wdt_probe()
204 		return -ENOMEM;  in rti_wdt_probe()
210 	wdt->freq = clk_get_rate(clk);  in rti_wdt_probe()
214 	if (!wdt->freq) {  in rti_wdt_probe()
216 		return -EINVAL;  in rti_wdt_probe()
224 	if (wdt->freq < 32768)  in rti_wdt_probe()
225 		wdt->freq = wdt->freq * 9 / 10;  in rti_wdt_probe()
230 		pm_runtime_disable(&pdev->dev);  in rti_wdt_probe()
234 	platform_set_drvdata(pdev, wdt);  in rti_wdt_probe()
236 	wdd = &wdt->wdd;  in rti_wdt_probe()
237 	wdd->info = &rti_wdt_info;  in rti_wdt_probe()
238 	wdd->ops = &rti_wdt_ops;  in rti_wdt_probe()
239 	wdd->min_timeout = 1;  in rti_wdt_probe()
240 	wdd->max_hw_heartbeat_ms = (WDT_PRELOAD_MAX << WDT_PRELOAD_SHIFT) /  in rti_wdt_probe()
241 		wdt->freq * 1000;  in rti_wdt_probe()
242 	wdd->parent = dev;  in rti_wdt_probe()
244 	watchdog_set_drvdata(wdd, wdt);  in rti_wdt_probe()
248 	wdt->base = devm_platform_ioremap_resource(pdev, 0);  in rti_wdt_probe()
249 	if (IS_ERR(wdt->base)) {  in rti_wdt_probe()
250 		ret = PTR_ERR(wdt->base);  in rti_wdt_probe()
254 	if (readl(wdt->base + RTIDWDCTRL) == WDENABLE_KEY) {  in rti_wdt_probe()
260 		set_bit(WDOG_HW_RUNNING, &wdd->status);  in rti_wdt_probe()
262 		heartbeat_ms = readl(wdt->base + RTIDWDPRLD);  in rti_wdt_probe()
265 		do_div(heartbeat_ms, wdt->freq);  in rti_wdt_probe()
273 		wsize = readl(wdt->base + RTIWWDSIZECTRL);  in rti_wdt_probe()
280 		last_ping = heartbeat_ms - time_left_ms;  in rti_wdt_probe()
301 	pm_runtime_put_sync(&pdev->dev);  in rti_wdt_probe()
302 	pm_runtime_disable(&pdev->dev);  in rti_wdt_probe()
309 	struct rti_wdt_device *wdt = platform_get_drvdata(pdev);  in rti_wdt_remove()  local
311 	watchdog_unregister_device(&wdt->wdd);  in rti_wdt_remove()
312 	pm_runtime_put(&pdev->dev);  in rti_wdt_remove()
313 	pm_runtime_disable(&pdev->dev);  in rti_wdt_remove()
319 	{ .compatible = "ti,j7-rti-wdt", },
326 		.name = "rti-wdt",
335 MODULE_AUTHOR("Tero Kristo <t-kristo@ti.com>");
336 MODULE_DESCRIPTION("K3 RTI Watchdog Driver");
345 MODULE_ALIAS("platform:rti-wdt");