1 // SPDX-License-Identifier: GPL-2.0-or-later
5  * Copyright (c) 2014 Oleksij Rempel <linux@rempel-privat.de>
16 #include <linux/reset.h>
25 /* This bit set if timeout reached. Cleared by SW. */
27 /* HW Reset on timeout */
35  * depends on used clock: T = WDCLK * (0xff + 1) * 4
71 	iowrite32(0xaa, priv->iobase + HW_WDFEED);  in asm9260_wdt_feed()
72 	iowrite32(0x55, priv->iobase + HW_WDFEED);  in asm9260_wdt_feed()
82 	counter = ioread32(priv->iobase + HW_WDTV);  in asm9260_wdt_gettimeleft()
84 	return counter / priv->wdt_freq;  in asm9260_wdt_gettimeleft()
92 	counter = wdd->timeout * priv->wdt_freq;  in asm9260_wdt_updatetimeout()
94 	iowrite32(counter, priv->iobase + HW_WDTC);  in asm9260_wdt_updatetimeout()
104 	if (priv->mode == HW_RESET)  in asm9260_wdt_enable()
107 	iowrite32(BM_MOD_WDEN | mode, priv->iobase + HW_WDMOD);  in asm9260_wdt_enable()
120 	/* The only way to disable WD is to reset it. */  in asm9260_wdt_disable()
121 	reset_control_assert(priv->rst);  in asm9260_wdt_disable()
122 	reset_control_deassert(priv->rst);  in asm9260_wdt_disable()
129 	wdd->timeout = to;  in asm9260_wdt_settimeout()
139 	iowrite32(BM_MOD_WDEN | BM_MOD_WDRESET, priv->iobase + HW_WDMOD);  in asm9260_wdt_sys_reset()
141 	iowrite32(0xff, priv->iobase + HW_WDTC);  in asm9260_wdt_sys_reset()
143 	asm9260_wdt_feed(&priv->wdd);  in asm9260_wdt_sys_reset()
145 	 * Then write wrong pattern to the feed to trigger reset  in asm9260_wdt_sys_reset()
148 	iowrite32(0xff, priv->iobase + HW_WDFEED);  in asm9260_wdt_sys_reset()
158 	stat = ioread32(priv->iobase + HW_WDMOD);  in asm9260_wdt_irq()
162 	if (priv->mode == DEBUG) {  in asm9260_wdt_irq()
163 		dev_info(priv->dev, "Watchdog Timeout. Do nothing.\n");  in asm9260_wdt_irq()
165 		dev_info(priv->dev, "Watchdog Timeout. Doing SW Reset.\n");  in asm9260_wdt_irq()
208 	priv->clk = devm_clk_get(priv->dev, "mod");  in asm9260_wdt_get_dt_clks()
209 	if (IS_ERR(priv->clk)) {  in asm9260_wdt_get_dt_clks()
210 		dev_err(priv->dev, "Failed to get \"mod\" clk\n");  in asm9260_wdt_get_dt_clks()
211 		return PTR_ERR(priv->clk);  in asm9260_wdt_get_dt_clks()
215 	priv->clk_ahb = devm_clk_get(priv->dev, "ahb");  in asm9260_wdt_get_dt_clks()
216 	if (IS_ERR(priv->clk_ahb)) {  in asm9260_wdt_get_dt_clks()
217 		dev_err(priv->dev, "Failed to get \"ahb\" clk\n");  in asm9260_wdt_get_dt_clks()
218 		return PTR_ERR(priv->clk_ahb);  in asm9260_wdt_get_dt_clks()
221 	err = clk_prepare_enable(priv->clk_ahb);  in asm9260_wdt_get_dt_clks()
223 		dev_err(priv->dev, "Failed to enable ahb_clk!\n");  in asm9260_wdt_get_dt_clks()
226 	err = devm_add_action_or_reset(priv->dev,  in asm9260_wdt_get_dt_clks()
228 				       priv->clk_ahb);  in asm9260_wdt_get_dt_clks()
232 	err = clk_set_rate(priv->clk, CLOCK_FREQ);  in asm9260_wdt_get_dt_clks()
234 		dev_err(priv->dev, "Failed to set rate!\n");  in asm9260_wdt_get_dt_clks()
238 	err = clk_prepare_enable(priv->clk);  in asm9260_wdt_get_dt_clks()
240 		dev_err(priv->dev, "Failed to enable clk!\n");  in asm9260_wdt_get_dt_clks()
243 	err = devm_add_action_or_reset(priv->dev,  in asm9260_wdt_get_dt_clks()
245 				       priv->clk);  in asm9260_wdt_get_dt_clks()
250 	clk = clk_get_rate(priv->clk);  in asm9260_wdt_get_dt_clks()
252 		dev_err(priv->dev, "Failed, clk is 0!\n");  in asm9260_wdt_get_dt_clks()
253 		return -EINVAL;  in asm9260_wdt_get_dt_clks()
256 	priv->wdt_freq = clk / 2;  in asm9260_wdt_get_dt_clks()
267 	priv->mode = HW_RESET;  in asm9260_wdt_get_dt_mode()
269 	ret = of_property_read_string(priv->dev->of_node,  in asm9260_wdt_get_dt_mode()
275 		priv->mode = HW_RESET;  in asm9260_wdt_get_dt_mode()
277 		priv->mode = SW_RESET;  in asm9260_wdt_get_dt_mode()
279 		priv->mode = DEBUG;  in asm9260_wdt_get_dt_mode()
281 		dev_warn(priv->dev, "unknown reset-type: %s. Using default \"hw\" mode.",  in asm9260_wdt_get_dt_mode()
287 	struct device *dev = &pdev->dev;  in asm9260_wdt_probe()
295 		return -ENOMEM;  in asm9260_wdt_probe()
297 	priv->dev = dev;  in asm9260_wdt_probe()
299 	priv->iobase = devm_platform_ioremap_resource(pdev, 0);  in asm9260_wdt_probe()
300 	if (IS_ERR(priv->iobase))  in asm9260_wdt_probe()
301 		return PTR_ERR(priv->iobase);  in asm9260_wdt_probe()
303 	priv->rst = devm_reset_control_get_exclusive(dev, "wdt_rst");  in asm9260_wdt_probe()
304 	if (IS_ERR(priv->rst))  in asm9260_wdt_probe()
305 		return PTR_ERR(priv->rst);  in asm9260_wdt_probe()
311 	wdd = &priv->wdd;  in asm9260_wdt_probe()
312 	wdd->info = &asm9260_wdt_ident;  in asm9260_wdt_probe()
313 	wdd->ops = &asm9260_wdt_ops;  in asm9260_wdt_probe()
314 	wdd->min_timeout = 1;  in asm9260_wdt_probe()
315 	wdd->max_timeout = BM_WDTC_MAX(priv->wdt_freq);  in asm9260_wdt_probe()
316 	wdd->parent = dev;  in asm9260_wdt_probe()
321 	 * If 'timeout-sec' unspecified in devicetree, assume a 30 second  in asm9260_wdt_probe()
322 	 * default, unless the max timeout is less than 30 seconds, then use  in asm9260_wdt_probe()
325 	wdd->timeout = ASM9260_WDT_DEFAULT_TIMEOUT;  in asm9260_wdt_probe()
330 	if (priv->mode != HW_RESET)  in asm9260_wdt_probe()
331 		priv->irq = platform_get_irq(pdev, 0);  in asm9260_wdt_probe()
333 	if (priv->irq > 0) {  in asm9260_wdt_probe()
338 		ret = devm_request_irq(dev, priv->irq, asm9260_wdt_irq, 0,  in asm9260_wdt_probe()
339 				       pdev->name, priv);  in asm9260_wdt_probe()
354 	dev_info(dev, "Watchdog enabled (timeout: %d sec, mode: %s)\n",  in asm9260_wdt_probe()
355 		 wdd->timeout, mode_name[priv->mode]);  in asm9260_wdt_probe()
360 	{ .compatible = "alphascale,asm9260-wdt"},
367 		.name = "asm9260-wdt",
375 MODULE_AUTHOR("Oleksij Rempel <linux@rempel-privat.de>");