1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Watchdog driver for Faraday Technology FTWDT010 |
4 | * |
5 | * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org> |
6 | * |
7 | * Inspired by the out-of-tree drivers from OpenWRT: |
8 | * Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt> |
9 | */ |
10 | |
11 | #include <linux/bitops.h> |
12 | #include <linux/init.h> |
13 | #include <linux/interrupt.h> |
14 | #include <linux/io.h> |
15 | #include <linux/kernel.h> |
16 | #include <linux/module.h> |
17 | #include <linux/mod_devicetable.h> |
18 | #include <linux/platform_device.h> |
19 | #include <linux/slab.h> |
20 | #include <linux/watchdog.h> |
21 | |
22 | #define FTWDT010_WDCOUNTER 0x0 |
23 | #define FTWDT010_WDLOAD 0x4 |
24 | #define FTWDT010_WDRESTART 0x8 |
25 | #define FTWDT010_WDCR 0xC |
26 | |
27 | #define WDRESTART_MAGIC 0x5AB9 |
28 | |
29 | #define WDCR_CLOCK_5MHZ BIT(4) |
30 | #define WDCR_WDEXT BIT(3) |
31 | #define WDCR_WDINTR BIT(2) |
32 | #define WDCR_SYS_RST BIT(1) |
33 | #define WDCR_ENABLE BIT(0) |
34 | |
35 | #define WDT_CLOCK 5000000 /* 5 MHz */ |
36 | |
37 | struct ftwdt010_wdt { |
38 | struct watchdog_device wdd; |
39 | struct device *dev; |
40 | void __iomem *base; |
41 | bool has_irq; |
42 | }; |
43 | |
44 | static inline |
45 | struct ftwdt010_wdt *to_ftwdt010_wdt(struct watchdog_device *wdd) |
46 | { |
47 | return container_of(wdd, struct ftwdt010_wdt, wdd); |
48 | } |
49 | |
50 | static void ftwdt010_enable(struct ftwdt010_wdt *gwdt, |
51 | unsigned int timeout, |
52 | bool need_irq) |
53 | { |
54 | u32 enable; |
55 | |
56 | writel(val: timeout * WDT_CLOCK, addr: gwdt->base + FTWDT010_WDLOAD); |
57 | writel(WDRESTART_MAGIC, addr: gwdt->base + FTWDT010_WDRESTART); |
58 | /* set clock before enabling */ |
59 | enable = WDCR_CLOCK_5MHZ | WDCR_SYS_RST; |
60 | writel(val: enable, addr: gwdt->base + FTWDT010_WDCR); |
61 | if (need_irq) |
62 | enable |= WDCR_WDINTR; |
63 | enable |= WDCR_ENABLE; |
64 | writel(val: enable, addr: gwdt->base + FTWDT010_WDCR); |
65 | } |
66 | |
67 | static int ftwdt010_wdt_start(struct watchdog_device *wdd) |
68 | { |
69 | struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd); |
70 | |
71 | ftwdt010_enable(gwdt, timeout: wdd->timeout, need_irq: gwdt->has_irq); |
72 | return 0; |
73 | } |
74 | |
75 | static int ftwdt010_wdt_stop(struct watchdog_device *wdd) |
76 | { |
77 | struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd); |
78 | |
79 | writel(val: 0, addr: gwdt->base + FTWDT010_WDCR); |
80 | |
81 | return 0; |
82 | } |
83 | |
84 | static int ftwdt010_wdt_ping(struct watchdog_device *wdd) |
85 | { |
86 | struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd); |
87 | |
88 | writel(WDRESTART_MAGIC, addr: gwdt->base + FTWDT010_WDRESTART); |
89 | |
90 | return 0; |
91 | } |
92 | |
93 | static int ftwdt010_wdt_set_timeout(struct watchdog_device *wdd, |
94 | unsigned int timeout) |
95 | { |
96 | wdd->timeout = timeout; |
97 | if (watchdog_active(wdd)) |
98 | ftwdt010_wdt_start(wdd); |
99 | |
100 | return 0; |
101 | } |
102 | |
103 | static int ftwdt010_wdt_restart(struct watchdog_device *wdd, |
104 | unsigned long action, void *data) |
105 | { |
106 | ftwdt010_enable(gwdt: to_ftwdt010_wdt(wdd), timeout: 0, need_irq: false); |
107 | return 0; |
108 | } |
109 | |
110 | static irqreturn_t ftwdt010_wdt_interrupt(int irq, void *data) |
111 | { |
112 | struct ftwdt010_wdt *gwdt = data; |
113 | |
114 | watchdog_notify_pretimeout(wdd: &gwdt->wdd); |
115 | |
116 | return IRQ_HANDLED; |
117 | } |
118 | |
119 | static const struct watchdog_ops ftwdt010_wdt_ops = { |
120 | .start = ftwdt010_wdt_start, |
121 | .stop = ftwdt010_wdt_stop, |
122 | .ping = ftwdt010_wdt_ping, |
123 | .set_timeout = ftwdt010_wdt_set_timeout, |
124 | .restart = ftwdt010_wdt_restart, |
125 | .owner = THIS_MODULE, |
126 | }; |
127 | |
128 | static const struct watchdog_info ftwdt010_wdt_info = { |
129 | .options = WDIOF_KEEPALIVEPING |
130 | | WDIOF_MAGICCLOSE |
131 | | WDIOF_SETTIMEOUT, |
132 | .identity = KBUILD_MODNAME, |
133 | }; |
134 | |
135 | |
136 | static int ftwdt010_wdt_probe(struct platform_device *pdev) |
137 | { |
138 | struct device *dev = &pdev->dev; |
139 | struct ftwdt010_wdt *gwdt; |
140 | unsigned int reg; |
141 | int irq; |
142 | int ret; |
143 | |
144 | gwdt = devm_kzalloc(dev, size: sizeof(*gwdt), GFP_KERNEL); |
145 | if (!gwdt) |
146 | return -ENOMEM; |
147 | |
148 | gwdt->base = devm_platform_ioremap_resource(pdev, index: 0); |
149 | if (IS_ERR(ptr: gwdt->base)) |
150 | return PTR_ERR(ptr: gwdt->base); |
151 | |
152 | gwdt->dev = dev; |
153 | gwdt->wdd.info = &ftwdt010_wdt_info; |
154 | gwdt->wdd.ops = &ftwdt010_wdt_ops; |
155 | gwdt->wdd.min_timeout = 1; |
156 | gwdt->wdd.max_timeout = 0xFFFFFFFF / WDT_CLOCK; |
157 | gwdt->wdd.parent = dev; |
158 | |
159 | /* |
160 | * If 'timeout-sec' unspecified in devicetree, assume a 13 second |
161 | * default. |
162 | */ |
163 | gwdt->wdd.timeout = 13U; |
164 | watchdog_init_timeout(wdd: &gwdt->wdd, timeout_parm: 0, dev); |
165 | |
166 | reg = readw(addr: gwdt->base + FTWDT010_WDCR); |
167 | if (reg & WDCR_ENABLE) { |
168 | /* Watchdog was enabled by the bootloader, disable it. */ |
169 | reg &= ~WDCR_ENABLE; |
170 | writel(val: reg, addr: gwdt->base + FTWDT010_WDCR); |
171 | } |
172 | |
173 | irq = platform_get_irq(pdev, 0); |
174 | if (irq > 0) { |
175 | ret = devm_request_irq(dev, irq, handler: ftwdt010_wdt_interrupt, irqflags: 0, |
176 | devname: "watchdog bark" , dev_id: gwdt); |
177 | if (ret) |
178 | return ret; |
179 | gwdt->has_irq = true; |
180 | } |
181 | |
182 | ret = devm_watchdog_register_device(dev, &gwdt->wdd); |
183 | if (ret) |
184 | return ret; |
185 | |
186 | /* Set up platform driver data */ |
187 | platform_set_drvdata(pdev, data: gwdt); |
188 | dev_info(dev, "FTWDT010 watchdog driver enabled\n" ); |
189 | |
190 | return 0; |
191 | } |
192 | |
193 | static int __maybe_unused ftwdt010_wdt_suspend(struct device *dev) |
194 | { |
195 | struct ftwdt010_wdt *gwdt = dev_get_drvdata(dev); |
196 | unsigned int reg; |
197 | |
198 | reg = readw(addr: gwdt->base + FTWDT010_WDCR); |
199 | reg &= ~WDCR_ENABLE; |
200 | writel(val: reg, addr: gwdt->base + FTWDT010_WDCR); |
201 | |
202 | return 0; |
203 | } |
204 | |
205 | static int __maybe_unused ftwdt010_wdt_resume(struct device *dev) |
206 | { |
207 | struct ftwdt010_wdt *gwdt = dev_get_drvdata(dev); |
208 | unsigned int reg; |
209 | |
210 | if (watchdog_active(wdd: &gwdt->wdd)) { |
211 | reg = readw(addr: gwdt->base + FTWDT010_WDCR); |
212 | reg |= WDCR_ENABLE; |
213 | writel(val: reg, addr: gwdt->base + FTWDT010_WDCR); |
214 | } |
215 | |
216 | return 0; |
217 | } |
218 | |
219 | static const struct dev_pm_ops ftwdt010_wdt_dev_pm_ops = { |
220 | SET_SYSTEM_SLEEP_PM_OPS(ftwdt010_wdt_suspend, |
221 | ftwdt010_wdt_resume) |
222 | }; |
223 | |
224 | static const struct of_device_id ftwdt010_wdt_match[] = { |
225 | { .compatible = "faraday,ftwdt010" }, |
226 | { .compatible = "cortina,gemini-watchdog" }, |
227 | {}, |
228 | }; |
229 | MODULE_DEVICE_TABLE(of, ftwdt010_wdt_match); |
230 | |
231 | static struct platform_driver ftwdt010_wdt_driver = { |
232 | .probe = ftwdt010_wdt_probe, |
233 | .driver = { |
234 | .name = "ftwdt010-wdt" , |
235 | .of_match_table = ftwdt010_wdt_match, |
236 | .pm = &ftwdt010_wdt_dev_pm_ops, |
237 | }, |
238 | }; |
239 | module_platform_driver(ftwdt010_wdt_driver); |
240 | MODULE_AUTHOR("Linus Walleij" ); |
241 | MODULE_DESCRIPTION("Watchdog driver for Faraday Technology FTWDT010" ); |
242 | MODULE_LICENSE("GPL" ); |
243 | |