1 // SPDX-License-Identifier: GPL-2.0
3  * Window watchdog device driver for Xilinx Versal WWDT
5  * Copyright (C) 2022 - 2023, Advanced Micro Devices, Inc.
16 #include <linux/watchdog.h>
32 /* Enable and Status Register Masks */
44 		 "Watchdog time in seconds. (default="
48 		 "Watchdog closed window percentage. (default="
51  * struct xwwdt_device - Watchdog device structure
54  * @xilinx_wwdt_wdd: watchdog device structure
69 	struct watchdog_device *xilinx_wwdt_wdd = &xdev->xilinx_wwdt_wdd;  in xilinx_wwdt_start()
74 	time_out = xdev->freq * wdd->timeout;  in xilinx_wwdt_start()
75 	closed_timeout = div_u64(time_out * xdev->close_percent, 100);  in xilinx_wwdt_start()
76 	open_timeout = time_out - closed_timeout;  in xilinx_wwdt_start()
77 	wdd->min_hw_heartbeat_ms = xdev->close_percent * 10 * wdd->timeout;  in xilinx_wwdt_start()
79 	spin_lock(&xdev->spinlock);  in xilinx_wwdt_start()
81 	iowrite32(XWWDT_MWR_MASK, xdev->base + XWWDT_MWR_OFFSET);  in xilinx_wwdt_start()
82 	iowrite32(~(u32)XWWDT_ESR_WEN_MASK, xdev->base + XWWDT_ESR_OFFSET);  in xilinx_wwdt_start()
83 	iowrite32((u32)closed_timeout, xdev->base + XWWDT_FWR_OFFSET);  in xilinx_wwdt_start()
84 	iowrite32((u32)open_timeout, xdev->base + XWWDT_SWR_OFFSET);  in xilinx_wwdt_start()
86 	/* Enable the window watchdog timer */  in xilinx_wwdt_start()
87 	control_status_reg = ioread32(xdev->base + XWWDT_ESR_OFFSET);  in xilinx_wwdt_start()
89 	iowrite32(control_status_reg, xdev->base + XWWDT_ESR_OFFSET);  in xilinx_wwdt_start()
91 	spin_unlock(&xdev->spinlock);  in xilinx_wwdt_start()
93 	dev_dbg(xilinx_wwdt_wdd->parent, "Watchdog Started!\n");  in xilinx_wwdt_start()
103 	spin_lock(&xdev->spinlock);  in xilinx_wwdt_keepalive()
105 	/* Enable write access control bit for the window watchdog */  in xilinx_wwdt_keepalive()
106 	iowrite32(XWWDT_MWR_MASK, xdev->base + XWWDT_MWR_OFFSET);  in xilinx_wwdt_keepalive()
108 	/* Trigger restart kick to watchdog */  in xilinx_wwdt_keepalive()
109 	control_status_reg = ioread32(xdev->base + XWWDT_ESR_OFFSET);  in xilinx_wwdt_keepalive()
111 	iowrite32(control_status_reg, xdev->base + XWWDT_ESR_OFFSET);  in xilinx_wwdt_keepalive()
113 	spin_unlock(&xdev->spinlock);  in xilinx_wwdt_keepalive()
122 	.identity = "xlnx_window watchdog",
134 	struct device *dev = &pdev->dev;  in xwwdt_probe()
141 		return -ENOMEM;  in xwwdt_probe()
143 	xilinx_wwdt_wdd = &xdev->xilinx_wwdt_wdd;  in xwwdt_probe()
144 	xilinx_wwdt_wdd->info = &xilinx_wwdt_ident;  in xwwdt_probe()
145 	xilinx_wwdt_wdd->ops = &xilinx_wwdt_ops;  in xwwdt_probe()
146 	xilinx_wwdt_wdd->parent = dev;  in xwwdt_probe()
148 	xdev->base = devm_platform_ioremap_resource(pdev, 0);  in xwwdt_probe()
149 	if (IS_ERR(xdev->base))  in xwwdt_probe()
150 		return PTR_ERR(xdev->base);  in xwwdt_probe()
156 	xdev->freq = clk_get_rate(clk);  in xwwdt_probe()
157 	if (!xdev->freq)  in xwwdt_probe()
158 		return -EINVAL;  in xwwdt_probe()
160 	xilinx_wwdt_wdd->min_timeout = XWWDT_MIN_TIMEOUT;  in xwwdt_probe()
161 	xilinx_wwdt_wdd->timeout = XWWDT_DEFAULT_TIMEOUT;  in xwwdt_probe()
162 	xilinx_wwdt_wdd->max_hw_heartbeat_ms = 1000 * xilinx_wwdt_wdd->timeout;  in xwwdt_probe()
165 		xdev->close_percent = XWWDT_CLOSE_WINDOW_PERCENT;  in xwwdt_probe()
167 		xdev->close_percent = closed_window_percent;  in xwwdt_probe()
169 	watchdog_init_timeout(xilinx_wwdt_wdd, wwdt_timeout, &pdev->dev);  in xwwdt_probe()
170 	spin_lock_init(&xdev->spinlock);  in xwwdt_probe()
178 	dev_info(dev, "Xilinx window watchdog Timer with timeout %ds\n",  in xwwdt_probe()
179 		 xilinx_wwdt_wdd->timeout);  in xwwdt_probe()
185 	{ .compatible = "xlnx,versal-wwdt", },
193 		.name = "Xilinx window watchdog",
201 MODULE_DESCRIPTION("Xilinx window watchdog driver");