Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
eca10ae6 | 2 | /* |
766a2aad | 3 | * Watchdog driver for Faraday Technology FTWDT010 |
eca10ae6 LW |
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> | |
eca10ae6 LW |
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> | |
cc85f87a | 17 | #include <linux/mod_devicetable.h> |
eca10ae6 LW |
18 | #include <linux/platform_device.h> |
19 | #include <linux/slab.h> | |
20 | #include <linux/watchdog.h> | |
21 | ||
766a2aad LW |
22 | #define FTWDT010_WDCOUNTER 0x0 |
23 | #define FTWDT010_WDLOAD 0x4 | |
24 | #define FTWDT010_WDRESTART 0x8 | |
25 | #define FTWDT010_WDCR 0xC | |
eca10ae6 LW |
26 | |
27 | #define WDRESTART_MAGIC 0x5AB9 | |
28 | ||
29 | #define WDCR_CLOCK_5MHZ BIT(4) | |
d5433fd6 LW |
30 | #define WDCR_WDEXT BIT(3) |
31 | #define WDCR_WDINTR BIT(2) | |
eca10ae6 LW |
32 | #define WDCR_SYS_RST BIT(1) |
33 | #define WDCR_ENABLE BIT(0) | |
34 | ||
35 | #define WDT_CLOCK 5000000 /* 5 MHz */ | |
36 | ||
766a2aad | 37 | struct ftwdt010_wdt { |
eca10ae6 LW |
38 | struct watchdog_device wdd; |
39 | struct device *dev; | |
40 | void __iomem *base; | |
d5433fd6 | 41 | bool has_irq; |
eca10ae6 LW |
42 | }; |
43 | ||
44 | static inline | |
766a2aad | 45 | struct ftwdt010_wdt *to_ftwdt010_wdt(struct watchdog_device *wdd) |
eca10ae6 | 46 | { |
766a2aad | 47 | return container_of(wdd, struct ftwdt010_wdt, wdd); |
eca10ae6 LW |
48 | } |
49 | ||
64ee9375 SA |
50 | static void ftwdt010_enable(struct ftwdt010_wdt *gwdt, |
51 | unsigned int timeout, | |
52 | bool need_irq) | |
eca10ae6 | 53 | { |
d5433fd6 | 54 | u32 enable; |
eca10ae6 | 55 | |
64ee9375 | 56 | writel(timeout * WDT_CLOCK, gwdt->base + FTWDT010_WDLOAD); |
766a2aad | 57 | writel(WDRESTART_MAGIC, gwdt->base + FTWDT010_WDRESTART); |
eca10ae6 | 58 | /* set clock before enabling */ |
d5433fd6 LW |
59 | enable = WDCR_CLOCK_5MHZ | WDCR_SYS_RST; |
60 | writel(enable, gwdt->base + FTWDT010_WDCR); | |
64ee9375 | 61 | if (need_irq) |
d5433fd6 LW |
62 | enable |= WDCR_WDINTR; |
63 | enable |= WDCR_ENABLE; | |
64 | writel(enable, gwdt->base + FTWDT010_WDCR); | |
64ee9375 | 65 | } |
eca10ae6 | 66 | |
64ee9375 SA |
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, wdd->timeout, gwdt->has_irq); | |
eca10ae6 LW |
72 | return 0; |
73 | } | |
74 | ||
766a2aad | 75 | static int ftwdt010_wdt_stop(struct watchdog_device *wdd) |
eca10ae6 | 76 | { |
766a2aad | 77 | struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd); |
eca10ae6 | 78 | |
766a2aad | 79 | writel(0, gwdt->base + FTWDT010_WDCR); |
eca10ae6 LW |
80 | |
81 | return 0; | |
82 | } | |
83 | ||
766a2aad | 84 | static int ftwdt010_wdt_ping(struct watchdog_device *wdd) |
eca10ae6 | 85 | { |
766a2aad | 86 | struct ftwdt010_wdt *gwdt = to_ftwdt010_wdt(wdd); |
eca10ae6 | 87 | |
766a2aad | 88 | writel(WDRESTART_MAGIC, gwdt->base + FTWDT010_WDRESTART); |
eca10ae6 LW |
89 | |
90 | return 0; | |
91 | } | |
92 | ||
766a2aad | 93 | static int ftwdt010_wdt_set_timeout(struct watchdog_device *wdd, |
eca10ae6 LW |
94 | unsigned int timeout) |
95 | { | |
96 | wdd->timeout = timeout; | |
97 | if (watchdog_active(wdd)) | |
766a2aad | 98 | ftwdt010_wdt_start(wdd); |
eca10ae6 LW |
99 | |
100 | return 0; | |
101 | } | |
102 | ||
64ee9375 SA |
103 | static int ftwdt010_wdt_restart(struct watchdog_device *wdd, |
104 | unsigned long action, void *data) | |
105 | { | |
106 | ftwdt010_enable(to_ftwdt010_wdt(wdd), 0, false); | |
107 | return 0; | |
108 | } | |
109 | ||
766a2aad | 110 | static irqreturn_t ftwdt010_wdt_interrupt(int irq, void *data) |
eca10ae6 | 111 | { |
766a2aad | 112 | struct ftwdt010_wdt *gwdt = data; |
eca10ae6 LW |
113 | |
114 | watchdog_notify_pretimeout(&gwdt->wdd); | |
115 | ||
116 | return IRQ_HANDLED; | |
117 | } | |
118 | ||
766a2aad LW |
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, | |
64ee9375 | 124 | .restart = ftwdt010_wdt_restart, |
eca10ae6 LW |
125 | .owner = THIS_MODULE, |
126 | }; | |
127 | ||
766a2aad | 128 | static const struct watchdog_info ftwdt010_wdt_info = { |
eca10ae6 LW |
129 | .options = WDIOF_KEEPALIVEPING |
130 | | WDIOF_MAGICCLOSE | |
131 | | WDIOF_SETTIMEOUT, | |
132 | .identity = KBUILD_MODNAME, | |
133 | }; | |
134 | ||
135 | ||
766a2aad | 136 | static int ftwdt010_wdt_probe(struct platform_device *pdev) |
eca10ae6 LW |
137 | { |
138 | struct device *dev = &pdev->dev; | |
766a2aad | 139 | struct ftwdt010_wdt *gwdt; |
eca10ae6 LW |
140 | unsigned int reg; |
141 | int irq; | |
142 | int ret; | |
143 | ||
144 | gwdt = devm_kzalloc(dev, sizeof(*gwdt), GFP_KERNEL); | |
145 | if (!gwdt) | |
146 | return -ENOMEM; | |
147 | ||
0f0a6a28 | 148 | gwdt->base = devm_platform_ioremap_resource(pdev, 0); |
eca10ae6 LW |
149 | if (IS_ERR(gwdt->base)) |
150 | return PTR_ERR(gwdt->base); | |
151 | ||
eca10ae6 | 152 | gwdt->dev = dev; |
766a2aad LW |
153 | gwdt->wdd.info = &ftwdt010_wdt_info; |
154 | gwdt->wdd.ops = &ftwdt010_wdt_ops; | |
eca10ae6 LW |
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(&gwdt->wdd, 0, dev); | |
165 | ||
766a2aad | 166 | reg = readw(gwdt->base + FTWDT010_WDCR); |
eca10ae6 LW |
167 | if (reg & WDCR_ENABLE) { |
168 | /* Watchdog was enabled by the bootloader, disable it. */ | |
169 | reg &= ~WDCR_ENABLE; | |
766a2aad | 170 | writel(reg, gwdt->base + FTWDT010_WDCR); |
eca10ae6 LW |
171 | } |
172 | ||
d5433fd6 | 173 | irq = platform_get_irq(pdev, 0); |
695bfff5 | 174 | if (irq > 0) { |
d5433fd6 LW |
175 | ret = devm_request_irq(dev, irq, ftwdt010_wdt_interrupt, 0, |
176 | "watchdog bark", gwdt); | |
177 | if (ret) | |
178 | return ret; | |
179 | gwdt->has_irq = true; | |
180 | } | |
eca10ae6 LW |
181 | |
182 | ret = devm_watchdog_register_device(dev, &gwdt->wdd); | |
2d065d2e | 183 | if (ret) |
eca10ae6 | 184 | return ret; |
eca10ae6 LW |
185 | |
186 | /* Set up platform driver data */ | |
187 | platform_set_drvdata(pdev, gwdt); | |
766a2aad | 188 | dev_info(dev, "FTWDT010 watchdog driver enabled\n"); |
eca10ae6 LW |
189 | |
190 | return 0; | |
191 | } | |
192 | ||
766a2aad | 193 | static int __maybe_unused ftwdt010_wdt_suspend(struct device *dev) |
eca10ae6 | 194 | { |
766a2aad | 195 | struct ftwdt010_wdt *gwdt = dev_get_drvdata(dev); |
eca10ae6 LW |
196 | unsigned int reg; |
197 | ||
766a2aad | 198 | reg = readw(gwdt->base + FTWDT010_WDCR); |
eca10ae6 | 199 | reg &= ~WDCR_ENABLE; |
766a2aad | 200 | writel(reg, gwdt->base + FTWDT010_WDCR); |
eca10ae6 LW |
201 | |
202 | return 0; | |
203 | } | |
204 | ||
766a2aad | 205 | static int __maybe_unused ftwdt010_wdt_resume(struct device *dev) |
eca10ae6 | 206 | { |
766a2aad | 207 | struct ftwdt010_wdt *gwdt = dev_get_drvdata(dev); |
eca10ae6 LW |
208 | unsigned int reg; |
209 | ||
210 | if (watchdog_active(&gwdt->wdd)) { | |
766a2aad | 211 | reg = readw(gwdt->base + FTWDT010_WDCR); |
eca10ae6 | 212 | reg |= WDCR_ENABLE; |
766a2aad | 213 | writel(reg, gwdt->base + FTWDT010_WDCR); |
eca10ae6 LW |
214 | } |
215 | ||
216 | return 0; | |
217 | } | |
218 | ||
766a2aad LW |
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) | |
eca10ae6 LW |
222 | }; |
223 | ||
766a2aad LW |
224 | static const struct of_device_id ftwdt010_wdt_match[] = { |
225 | { .compatible = "faraday,ftwdt010" }, | |
eca10ae6 LW |
226 | { .compatible = "cortina,gemini-watchdog" }, |
227 | {}, | |
228 | }; | |
766a2aad | 229 | MODULE_DEVICE_TABLE(of, ftwdt010_wdt_match); |
eca10ae6 | 230 | |
766a2aad LW |
231 | static struct platform_driver ftwdt010_wdt_driver = { |
232 | .probe = ftwdt010_wdt_probe, | |
eca10ae6 | 233 | .driver = { |
766a2aad | 234 | .name = "ftwdt010-wdt", |
cc85f87a | 235 | .of_match_table = ftwdt010_wdt_match, |
766a2aad | 236 | .pm = &ftwdt010_wdt_dev_pm_ops, |
eca10ae6 LW |
237 | }, |
238 | }; | |
766a2aad | 239 | module_platform_driver(ftwdt010_wdt_driver); |
eca10ae6 | 240 | MODULE_AUTHOR("Linus Walleij"); |
766a2aad | 241 | MODULE_DESCRIPTION("Watchdog driver for Faraday Technology FTWDT010"); |
eca10ae6 | 242 | MODULE_LICENSE("GPL"); |