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f865c352 PC |
1 | /* |
2 | * Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net> | |
3 | * JZ4740 Watchdog driver | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU General Public License as published by the | |
7 | * Free Software Foundation; either version 2 of the License, or (at your | |
8 | * option) any later version. | |
9 | * | |
10 | * You should have received a copy of the GNU General Public License along | |
11 | * with this program; if not, write to the Free Software Foundation, Inc., | |
12 | * 675 Mass Ave, Cambridge, MA 02139, USA. | |
13 | * | |
14 | */ | |
15 | ||
16 | #include <linux/module.h> | |
17 | #include <linux/moduleparam.h> | |
18 | #include <linux/types.h> | |
19 | #include <linux/kernel.h> | |
f865c352 | 20 | #include <linux/watchdog.h> |
f865c352 | 21 | #include <linux/platform_device.h> |
f865c352 PC |
22 | #include <linux/io.h> |
23 | #include <linux/device.h> | |
24 | #include <linux/clk.h> | |
25 | #include <linux/slab.h> | |
85f6df14 | 26 | #include <linux/err.h> |
6b96c722 | 27 | #include <linux/of.h> |
f865c352 PC |
28 | |
29 | #include <asm/mach-jz4740/timer.h> | |
30 | ||
31 | #define JZ_REG_WDT_TIMER_DATA 0x0 | |
32 | #define JZ_REG_WDT_COUNTER_ENABLE 0x4 | |
33 | #define JZ_REG_WDT_TIMER_COUNTER 0x8 | |
34 | #define JZ_REG_WDT_TIMER_CONTROL 0xC | |
35 | ||
36 | #define JZ_WDT_CLOCK_PCLK 0x1 | |
37 | #define JZ_WDT_CLOCK_RTC 0x2 | |
38 | #define JZ_WDT_CLOCK_EXT 0x4 | |
39 | ||
f865c352 PC |
40 | #define JZ_WDT_CLOCK_DIV_SHIFT 3 |
41 | ||
42 | #define JZ_WDT_CLOCK_DIV_1 (0 << JZ_WDT_CLOCK_DIV_SHIFT) | |
43 | #define JZ_WDT_CLOCK_DIV_4 (1 << JZ_WDT_CLOCK_DIV_SHIFT) | |
44 | #define JZ_WDT_CLOCK_DIV_16 (2 << JZ_WDT_CLOCK_DIV_SHIFT) | |
45 | #define JZ_WDT_CLOCK_DIV_64 (3 << JZ_WDT_CLOCK_DIV_SHIFT) | |
46 | #define JZ_WDT_CLOCK_DIV_256 (4 << JZ_WDT_CLOCK_DIV_SHIFT) | |
47 | #define JZ_WDT_CLOCK_DIV_1024 (5 << JZ_WDT_CLOCK_DIV_SHIFT) | |
48 | ||
49 | #define DEFAULT_HEARTBEAT 5 | |
50 | #define MAX_HEARTBEAT 2048 | |
51 | ||
85f6df14 AL |
52 | static bool nowayout = WATCHDOG_NOWAYOUT; |
53 | module_param(nowayout, bool, 0); | |
54 | MODULE_PARM_DESC(nowayout, | |
55 | "Watchdog cannot be stopped once started (default=" | |
56 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
f865c352 | 57 | |
85f6df14 AL |
58 | static unsigned int heartbeat = DEFAULT_HEARTBEAT; |
59 | module_param(heartbeat, uint, 0); | |
60 | MODULE_PARM_DESC(heartbeat, | |
61 | "Watchdog heartbeat period in seconds from 1 to " | |
62 | __MODULE_STRING(MAX_HEARTBEAT) ", default " | |
63 | __MODULE_STRING(DEFAULT_HEARTBEAT)); | |
f865c352 | 64 | |
85f6df14 AL |
65 | struct jz4740_wdt_drvdata { |
66 | struct watchdog_device wdt; | |
67 | void __iomem *base; | |
68 | struct clk *rtc_clk; | |
69 | }; | |
f865c352 | 70 | |
85f6df14 | 71 | static int jz4740_wdt_ping(struct watchdog_device *wdt_dev) |
f865c352 | 72 | { |
85f6df14 AL |
73 | struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); |
74 | ||
75 | writew(0x0, drvdata->base + JZ_REG_WDT_TIMER_COUNTER); | |
76 | return 0; | |
f865c352 PC |
77 | } |
78 | ||
85f6df14 AL |
79 | static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev, |
80 | unsigned int new_timeout) | |
f865c352 | 81 | { |
85f6df14 | 82 | struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); |
f865c352 PC |
83 | unsigned int rtc_clk_rate; |
84 | unsigned int timeout_value; | |
85 | unsigned short clock_div = JZ_WDT_CLOCK_DIV_1; | |
86 | ||
85f6df14 | 87 | rtc_clk_rate = clk_get_rate(drvdata->rtc_clk); |
f865c352 | 88 | |
85f6df14 | 89 | timeout_value = rtc_clk_rate * new_timeout; |
f865c352 PC |
90 | while (timeout_value > 0xffff) { |
91 | if (clock_div == JZ_WDT_CLOCK_DIV_1024) { | |
92 | /* Requested timeout too high; | |
93 | * use highest possible value. */ | |
94 | timeout_value = 0xffff; | |
95 | break; | |
96 | } | |
97 | timeout_value >>= 2; | |
98 | clock_div += (1 << JZ_WDT_CLOCK_DIV_SHIFT); | |
99 | } | |
100 | ||
85f6df14 AL |
101 | writeb(0x0, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE); |
102 | writew(clock_div, drvdata->base + JZ_REG_WDT_TIMER_CONTROL); | |
f865c352 | 103 | |
85f6df14 AL |
104 | writew((u16)timeout_value, drvdata->base + JZ_REG_WDT_TIMER_DATA); |
105 | writew(0x0, drvdata->base + JZ_REG_WDT_TIMER_COUNTER); | |
f865c352 | 106 | writew(clock_div | JZ_WDT_CLOCK_RTC, |
85f6df14 | 107 | drvdata->base + JZ_REG_WDT_TIMER_CONTROL); |
f865c352 | 108 | |
85f6df14 | 109 | writeb(0x1, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE); |
f865c352 | 110 | |
0197c1c4 | 111 | wdt_dev->timeout = new_timeout; |
85f6df14 | 112 | return 0; |
f865c352 PC |
113 | } |
114 | ||
85f6df14 | 115 | static int jz4740_wdt_start(struct watchdog_device *wdt_dev) |
f865c352 | 116 | { |
85f6df14 AL |
117 | jz4740_timer_enable_watchdog(); |
118 | jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout); | |
f865c352 | 119 | |
85f6df14 | 120 | return 0; |
f865c352 PC |
121 | } |
122 | ||
85f6df14 | 123 | static int jz4740_wdt_stop(struct watchdog_device *wdt_dev) |
f865c352 | 124 | { |
85f6df14 | 125 | struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); |
742e4b63 | 126 | |
85f6df14 AL |
127 | jz4740_timer_disable_watchdog(); |
128 | writeb(0x0, drvdata->base + JZ_REG_WDT_COUNTER_ENABLE); | |
f865c352 | 129 | |
85f6df14 | 130 | return 0; |
f865c352 PC |
131 | } |
132 | ||
85f6df14 AL |
133 | static const struct watchdog_info jz4740_wdt_info = { |
134 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | |
f865c352 PC |
135 | .identity = "jz4740 Watchdog", |
136 | }; | |
137 | ||
85f6df14 | 138 | static const struct watchdog_ops jz4740_wdt_ops = { |
f865c352 | 139 | .owner = THIS_MODULE, |
85f6df14 AL |
140 | .start = jz4740_wdt_start, |
141 | .stop = jz4740_wdt_stop, | |
142 | .ping = jz4740_wdt_ping, | |
143 | .set_timeout = jz4740_wdt_set_timeout, | |
f865c352 PC |
144 | }; |
145 | ||
6b96c722 ZLK |
146 | #ifdef CONFIG_OF |
147 | static const struct of_device_id jz4740_wdt_of_matches[] = { | |
148 | { .compatible = "ingenic,jz4740-watchdog", }, | |
149 | { /* sentinel */ } | |
150 | }; | |
151 | MODULE_DEVICE_TABLE(of, jz4740_wdt_of_matches) | |
152 | #endif | |
153 | ||
2d991a16 | 154 | static int jz4740_wdt_probe(struct platform_device *pdev) |
f865c352 | 155 | { |
85f6df14 AL |
156 | struct jz4740_wdt_drvdata *drvdata; |
157 | struct watchdog_device *jz4740_wdt; | |
158 | struct resource *res; | |
159 | int ret; | |
160 | ||
161 | drvdata = devm_kzalloc(&pdev->dev, sizeof(struct jz4740_wdt_drvdata), | |
162 | GFP_KERNEL); | |
e26e74b1 | 163 | if (!drvdata) |
85f6df14 | 164 | return -ENOMEM; |
f865c352 | 165 | |
85f6df14 AL |
166 | if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT) |
167 | heartbeat = DEFAULT_HEARTBEAT; | |
f865c352 | 168 | |
85f6df14 AL |
169 | jz4740_wdt = &drvdata->wdt; |
170 | jz4740_wdt->info = &jz4740_wdt_info; | |
171 | jz4740_wdt->ops = &jz4740_wdt_ops; | |
172 | jz4740_wdt->timeout = heartbeat; | |
173 | jz4740_wdt->min_timeout = 1; | |
174 | jz4740_wdt->max_timeout = MAX_HEARTBEAT; | |
6551881c | 175 | jz4740_wdt->parent = &pdev->dev; |
85f6df14 AL |
176 | watchdog_set_nowayout(jz4740_wdt, nowayout); |
177 | watchdog_set_drvdata(jz4740_wdt, drvdata); | |
178 | ||
179 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
4c271bb6 TR |
180 | drvdata->base = devm_ioremap_resource(&pdev->dev, res); |
181 | if (IS_ERR(drvdata->base)) { | |
182 | ret = PTR_ERR(drvdata->base); | |
85f6df14 | 183 | goto err_out; |
f865c352 PC |
184 | } |
185 | ||
5f314970 | 186 | drvdata->rtc_clk = clk_get(&pdev->dev, "rtc"); |
85f6df14 AL |
187 | if (IS_ERR(drvdata->rtc_clk)) { |
188 | dev_err(&pdev->dev, "cannot find RTC clock\n"); | |
189 | ret = PTR_ERR(drvdata->rtc_clk); | |
190 | goto err_out; | |
f865c352 PC |
191 | } |
192 | ||
85f6df14 AL |
193 | ret = watchdog_register_device(&drvdata->wdt); |
194 | if (ret < 0) | |
f865c352 | 195 | goto err_disable_clk; |
f865c352 | 196 | |
85f6df14 | 197 | platform_set_drvdata(pdev, drvdata); |
f865c352 PC |
198 | return 0; |
199 | ||
200 | err_disable_clk: | |
85f6df14 AL |
201 | clk_put(drvdata->rtc_clk); |
202 | err_out: | |
f865c352 PC |
203 | return ret; |
204 | } | |
205 | ||
4b12b896 | 206 | static int jz4740_wdt_remove(struct platform_device *pdev) |
f865c352 | 207 | { |
85f6df14 | 208 | struct jz4740_wdt_drvdata *drvdata = platform_get_drvdata(pdev); |
f865c352 | 209 | |
85f6df14 AL |
210 | jz4740_wdt_stop(&drvdata->wdt); |
211 | watchdog_unregister_device(&drvdata->wdt); | |
212 | clk_put(drvdata->rtc_clk); | |
f865c352 PC |
213 | |
214 | return 0; | |
215 | } | |
216 | ||
f865c352 PC |
217 | static struct platform_driver jz4740_wdt_driver = { |
218 | .probe = jz4740_wdt_probe, | |
82268714 | 219 | .remove = jz4740_wdt_remove, |
f865c352 PC |
220 | .driver = { |
221 | .name = "jz4740-wdt", | |
6b96c722 | 222 | .of_match_table = of_match_ptr(jz4740_wdt_of_matches), |
f865c352 PC |
223 | }, |
224 | }; | |
225 | ||
b8ec6118 | 226 | module_platform_driver(jz4740_wdt_driver); |
f865c352 PC |
227 | |
228 | MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>"); | |
229 | MODULE_DESCRIPTION("jz4740 Watchdog Driver"); | |
f865c352 | 230 | MODULE_LICENSE("GPL"); |
f865c352 | 231 | MODULE_ALIAS("platform:jz4740-wdt"); |