Commit | Line | Data |
---|---|---|
a912e80b | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
f865c352 PC |
2 | /* |
3 | * Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net> | |
4 | * JZ4740 Watchdog driver | |
f865c352 PC |
5 | */ |
6 | ||
df04cce3 | 7 | #include <linux/mfd/ingenic-tcu.h> |
6d532143 | 8 | #include <linux/mfd/syscon.h> |
f865c352 PC |
9 | #include <linux/module.h> |
10 | #include <linux/moduleparam.h> | |
11 | #include <linux/types.h> | |
12 | #include <linux/kernel.h> | |
f865c352 | 13 | #include <linux/watchdog.h> |
f865c352 | 14 | #include <linux/platform_device.h> |
f865c352 PC |
15 | #include <linux/io.h> |
16 | #include <linux/device.h> | |
17 | #include <linux/clk.h> | |
18 | #include <linux/slab.h> | |
85f6df14 | 19 | #include <linux/err.h> |
6b96c722 | 20 | #include <linux/of.h> |
6d532143 | 21 | #include <linux/regmap.h> |
f865c352 | 22 | |
f865c352 PC |
23 | #define DEFAULT_HEARTBEAT 5 |
24 | #define MAX_HEARTBEAT 2048 | |
25 | ||
85f6df14 AL |
26 | static bool nowayout = WATCHDOG_NOWAYOUT; |
27 | module_param(nowayout, bool, 0); | |
28 | MODULE_PARM_DESC(nowayout, | |
29 | "Watchdog cannot be stopped once started (default=" | |
30 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
f865c352 | 31 | |
85f6df14 AL |
32 | static unsigned int heartbeat = DEFAULT_HEARTBEAT; |
33 | module_param(heartbeat, uint, 0); | |
34 | MODULE_PARM_DESC(heartbeat, | |
35 | "Watchdog heartbeat period in seconds from 1 to " | |
36 | __MODULE_STRING(MAX_HEARTBEAT) ", default " | |
37 | __MODULE_STRING(DEFAULT_HEARTBEAT)); | |
f865c352 | 38 | |
85f6df14 AL |
39 | struct jz4740_wdt_drvdata { |
40 | struct watchdog_device wdt; | |
6d532143 | 41 | struct regmap *map; |
1d9c3074 PC |
42 | struct clk *clk; |
43 | unsigned long clk_rate; | |
85f6df14 | 44 | }; |
f865c352 | 45 | |
85f6df14 | 46 | static int jz4740_wdt_ping(struct watchdog_device *wdt_dev) |
f865c352 | 47 | { |
85f6df14 AL |
48 | struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); |
49 | ||
6d532143 PC |
50 | regmap_write(drvdata->map, TCU_REG_WDT_TCNT, 0); |
51 | ||
85f6df14 | 52 | return 0; |
f865c352 PC |
53 | } |
54 | ||
85f6df14 AL |
55 | static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev, |
56 | unsigned int new_timeout) | |
f865c352 | 57 | { |
85f6df14 | 58 | struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); |
1d9c3074 | 59 | u16 timeout_value = (u16)(drvdata->clk_rate * new_timeout); |
6d532143 | 60 | unsigned int tcer; |
f865c352 | 61 | |
6d532143 PC |
62 | regmap_read(drvdata->map, TCU_REG_WDT_TCER, &tcer); |
63 | regmap_write(drvdata->map, TCU_REG_WDT_TCER, 0); | |
f865c352 | 64 | |
6d532143 PC |
65 | regmap_write(drvdata->map, TCU_REG_WDT_TDR, timeout_value); |
66 | regmap_write(drvdata->map, TCU_REG_WDT_TCNT, 0); | |
f865c352 | 67 | |
9b346118 | 68 | if (tcer & TCU_WDT_TCER_TCEN) |
6d532143 | 69 | regmap_write(drvdata->map, TCU_REG_WDT_TCER, TCU_WDT_TCER_TCEN); |
f865c352 | 70 | |
0197c1c4 | 71 | wdt_dev->timeout = new_timeout; |
85f6df14 | 72 | return 0; |
f865c352 PC |
73 | } |
74 | ||
85f6df14 | 75 | static int jz4740_wdt_start(struct watchdog_device *wdt_dev) |
f865c352 | 76 | { |
9b346118 | 77 | struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); |
6d532143 | 78 | unsigned int tcer; |
1d9c3074 | 79 | int ret; |
9b346118 | 80 | |
1d9c3074 PC |
81 | ret = clk_prepare_enable(drvdata->clk); |
82 | if (ret) | |
83 | return ret; | |
84 | ||
6d532143 | 85 | regmap_read(drvdata->map, TCU_REG_WDT_TCER, &tcer); |
9b346118 | 86 | |
85f6df14 | 87 | jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout); |
f865c352 | 88 | |
9b346118 PC |
89 | /* Start watchdog if it wasn't started already */ |
90 | if (!(tcer & TCU_WDT_TCER_TCEN)) | |
6d532143 | 91 | regmap_write(drvdata->map, TCU_REG_WDT_TCER, TCU_WDT_TCER_TCEN); |
9b346118 | 92 | |
85f6df14 | 93 | return 0; |
f865c352 PC |
94 | } |
95 | ||
85f6df14 | 96 | static int jz4740_wdt_stop(struct watchdog_device *wdt_dev) |
f865c352 | 97 | { |
85f6df14 | 98 | struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); |
742e4b63 | 99 | |
6d532143 | 100 | regmap_write(drvdata->map, TCU_REG_WDT_TCER, 0); |
1d9c3074 | 101 | clk_disable_unprepare(drvdata->clk); |
f865c352 | 102 | |
85f6df14 | 103 | return 0; |
f865c352 PC |
104 | } |
105 | ||
b4918057 PC |
106 | static int jz4740_wdt_restart(struct watchdog_device *wdt_dev, |
107 | unsigned long action, void *data) | |
108 | { | |
109 | wdt_dev->timeout = 0; | |
110 | jz4740_wdt_start(wdt_dev); | |
111 | return 0; | |
112 | } | |
113 | ||
85f6df14 AL |
114 | static const struct watchdog_info jz4740_wdt_info = { |
115 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | |
f865c352 PC |
116 | .identity = "jz4740 Watchdog", |
117 | }; | |
118 | ||
85f6df14 | 119 | static const struct watchdog_ops jz4740_wdt_ops = { |
f865c352 | 120 | .owner = THIS_MODULE, |
85f6df14 AL |
121 | .start = jz4740_wdt_start, |
122 | .stop = jz4740_wdt_stop, | |
123 | .ping = jz4740_wdt_ping, | |
124 | .set_timeout = jz4740_wdt_set_timeout, | |
b4918057 | 125 | .restart = jz4740_wdt_restart, |
f865c352 PC |
126 | }; |
127 | ||
6b96c722 ZLK |
128 | #ifdef CONFIG_OF |
129 | static const struct of_device_id jz4740_wdt_of_matches[] = { | |
130 | { .compatible = "ingenic,jz4740-watchdog", }, | |
71246c35 | 131 | { .compatible = "ingenic,jz4780-watchdog", }, |
6b96c722 ZLK |
132 | { /* sentinel */ } |
133 | }; | |
35ffa961 | 134 | MODULE_DEVICE_TABLE(of, jz4740_wdt_of_matches); |
6b96c722 ZLK |
135 | #endif |
136 | ||
2d991a16 | 137 | static int jz4740_wdt_probe(struct platform_device *pdev) |
f865c352 | 138 | { |
02189bb9 | 139 | struct device *dev = &pdev->dev; |
85f6df14 AL |
140 | struct jz4740_wdt_drvdata *drvdata; |
141 | struct watchdog_device *jz4740_wdt; | |
1d9c3074 PC |
142 | long rate; |
143 | int ret; | |
85f6df14 | 144 | |
02189bb9 | 145 | drvdata = devm_kzalloc(dev, sizeof(struct jz4740_wdt_drvdata), |
85f6df14 | 146 | GFP_KERNEL); |
e26e74b1 | 147 | if (!drvdata) |
85f6df14 | 148 | return -ENOMEM; |
f865c352 | 149 | |
1d9c3074 PC |
150 | drvdata->clk = devm_clk_get(&pdev->dev, "wdt"); |
151 | if (IS_ERR(drvdata->clk)) { | |
152 | dev_err(&pdev->dev, "cannot find WDT clock\n"); | |
153 | return PTR_ERR(drvdata->clk); | |
154 | } | |
155 | ||
156 | /* Set smallest clock possible */ | |
157 | rate = clk_round_rate(drvdata->clk, 1); | |
158 | if (rate < 0) | |
159 | return rate; | |
160 | ||
161 | ret = clk_set_rate(drvdata->clk, rate); | |
162 | if (ret) | |
163 | return ret; | |
f865c352 | 164 | |
1d9c3074 | 165 | drvdata->clk_rate = rate; |
85f6df14 AL |
166 | jz4740_wdt = &drvdata->wdt; |
167 | jz4740_wdt->info = &jz4740_wdt_info; | |
168 | jz4740_wdt->ops = &jz4740_wdt_ops; | |
85f6df14 | 169 | jz4740_wdt->min_timeout = 1; |
1d9c3074 PC |
170 | jz4740_wdt->max_timeout = 0xffff / rate; |
171 | jz4740_wdt->timeout = clamp(heartbeat, | |
172 | jz4740_wdt->min_timeout, | |
173 | jz4740_wdt->max_timeout); | |
02189bb9 | 174 | jz4740_wdt->parent = dev; |
85f6df14 AL |
175 | watchdog_set_nowayout(jz4740_wdt, nowayout); |
176 | watchdog_set_drvdata(jz4740_wdt, drvdata); | |
177 | ||
6d532143 | 178 | drvdata->map = device_node_to_regmap(dev->parent->of_node); |
29e85f53 | 179 | if (IS_ERR(drvdata->map)) { |
6d532143 | 180 | dev_err(dev, "regmap not found\n"); |
29e85f53 | 181 | return PTR_ERR(drvdata->map); |
6d532143 | 182 | } |
f865c352 | 183 | |
9ee644c9 | 184 | return devm_watchdog_register_device(dev, &drvdata->wdt); |
f865c352 PC |
185 | } |
186 | ||
f865c352 PC |
187 | static struct platform_driver jz4740_wdt_driver = { |
188 | .probe = jz4740_wdt_probe, | |
f865c352 PC |
189 | .driver = { |
190 | .name = "jz4740-wdt", | |
6b96c722 | 191 | .of_match_table = of_match_ptr(jz4740_wdt_of_matches), |
f865c352 PC |
192 | }, |
193 | }; | |
194 | ||
b8ec6118 | 195 | module_platform_driver(jz4740_wdt_driver); |
f865c352 PC |
196 | |
197 | MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>"); | |
198 | MODULE_DESCRIPTION("jz4740 Watchdog Driver"); | |
f865c352 | 199 | MODULE_LICENSE("GPL"); |
f865c352 | 200 | MODULE_ALIAS("platform:jz4740-wdt"); |