1 // SPDX-License-Identifier: GPL-2.0-or-later
4  *  JZ4740 Watchdog driver
7 #include <linux/mfd/ingenic-tcu.h>
13 #include <linux/watchdog.h>
29 		 "Watchdog cannot be stopped once started (default="
35 		"Watchdog heartbeat period in seconds from 1 to "
50 	regmap_write(drvdata->map, TCU_REG_WDT_TCNT, 0);  in jz4740_wdt_ping()
59 	u16 timeout_value = (u16)(drvdata->clk_rate * new_timeout);  in jz4740_wdt_set_timeout()
62 	regmap_read(drvdata->map, TCU_REG_WDT_TCER, &tcer);  in jz4740_wdt_set_timeout()
63 	regmap_write(drvdata->map, TCU_REG_WDT_TCER, 0);  in jz4740_wdt_set_timeout()
65 	regmap_write(drvdata->map, TCU_REG_WDT_TDR, timeout_value);  in jz4740_wdt_set_timeout()
66 	regmap_write(drvdata->map, TCU_REG_WDT_TCNT, 0);  in jz4740_wdt_set_timeout()
69 		regmap_write(drvdata->map, TCU_REG_WDT_TCER, TCU_WDT_TCER_TCEN);  in jz4740_wdt_set_timeout()
71 	wdt_dev->timeout = new_timeout;  in jz4740_wdt_set_timeout()
81 	ret = clk_prepare_enable(drvdata->clk);  in jz4740_wdt_start()
85 	regmap_read(drvdata->map, TCU_REG_WDT_TCER, &tcer);  in jz4740_wdt_start()
87 	jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout);  in jz4740_wdt_start()
89 	/* Start watchdog if it wasn't started already */  in jz4740_wdt_start()
91 		regmap_write(drvdata->map, TCU_REG_WDT_TCER, TCU_WDT_TCER_TCEN);  in jz4740_wdt_start()
100 	regmap_write(drvdata->map, TCU_REG_WDT_TCER, 0);  in jz4740_wdt_stop()
101 	clk_disable_unprepare(drvdata->clk);  in jz4740_wdt_stop()
109 	wdt_dev->timeout = 0;  in jz4740_wdt_restart()
116 	.identity = "jz4740 Watchdog",
130 	{ .compatible = "ingenic,jz4740-watchdog", },
131 	{ .compatible = "ingenic,jz4780-watchdog", },
139 	struct device *dev = &pdev->dev;  in jz4740_wdt_probe()
148 		return -ENOMEM;  in jz4740_wdt_probe()
150 	drvdata->clk = devm_clk_get(&pdev->dev, "wdt");  in jz4740_wdt_probe()
151 	if (IS_ERR(drvdata->clk)) {  in jz4740_wdt_probe()
152 		dev_err(&pdev->dev, "cannot find WDT clock\n");  in jz4740_wdt_probe()
153 		return PTR_ERR(drvdata->clk);  in jz4740_wdt_probe()
157 	rate = clk_round_rate(drvdata->clk, 1);  in jz4740_wdt_probe()
161 	ret = clk_set_rate(drvdata->clk, rate);  in jz4740_wdt_probe()
165 	drvdata->clk_rate = rate;  in jz4740_wdt_probe()
166 	jz4740_wdt = &drvdata->wdt;  in jz4740_wdt_probe()
167 	jz4740_wdt->info = &jz4740_wdt_info;  in jz4740_wdt_probe()
168 	jz4740_wdt->ops = &jz4740_wdt_ops;  in jz4740_wdt_probe()
169 	jz4740_wdt->min_timeout = 1;  in jz4740_wdt_probe()
170 	jz4740_wdt->max_timeout = 0xffff / rate;  in jz4740_wdt_probe()
171 	jz4740_wdt->timeout = clamp(heartbeat,  in jz4740_wdt_probe()
172 				    jz4740_wdt->min_timeout,  in jz4740_wdt_probe()
173 				    jz4740_wdt->max_timeout);  in jz4740_wdt_probe()
174 	jz4740_wdt->parent = dev;  in jz4740_wdt_probe()
178 	drvdata->map = device_node_to_regmap(dev->parent->of_node);  in jz4740_wdt_probe()
179 	if (!drvdata->map) {  in jz4740_wdt_probe()
181 		return -EINVAL;  in jz4740_wdt_probe()
184 	return devm_watchdog_register_device(dev, &drvdata->wdt);  in jz4740_wdt_probe()
190 		.name = "jz4740-wdt",
198 MODULE_DESCRIPTION("jz4740 Watchdog Driver");
200 MODULE_ALIAS("platform:jz4740-wdt");