Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
[linux-block.git] / drivers / watchdog / davinci_wdt.c
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1/*
2 * drivers/char/watchdog/davinci_wdt.c
3 *
4 * Watchdog driver for DaVinci DM644x/DM646x processors
5 *
f48f3cea 6 * Copyright (C) 2006-2013 Texas Instruments.
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7 *
8 * 2007 (c) MontaVista Software, Inc. This file is licensed under
9 * the terms of the GNU General Public License version 2. This program
10 * is licensed "as is" without any warranty of any kind, whether express
11 * or implied.
12 */
13
14#include <linux/module.h>
15#include <linux/moduleparam.h>
16#include <linux/types.h>
17#include <linux/kernel.h>
7d831bf5 18#include <linux/watchdog.h>
7d831bf5 19#include <linux/platform_device.h>
f78b0a8f 20#include <linux/io.h>
371d3525 21#include <linux/device.h>
9fd868f4 22#include <linux/clk.h>
6330c707 23#include <linux/err.h>
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24
25#define MODULE_NAME "DAVINCI-WDT: "
26
27#define DEFAULT_HEARTBEAT 60
28#define MAX_HEARTBEAT 600 /* really the max margin is 264/27MHz*/
29
30/* Timer register set definition */
31#define PID12 (0x0)
32#define EMUMGT (0x4)
33#define TIM12 (0x10)
34#define TIM34 (0x14)
35#define PRD12 (0x18)
36#define PRD34 (0x1C)
37#define TCR (0x20)
38#define TGCR (0x24)
39#define WDTCR (0x28)
40
41/* TCR bit definitions */
42#define ENAMODE12_DISABLED (0 << 6)
43#define ENAMODE12_ONESHOT (1 << 6)
44#define ENAMODE12_PERIODIC (2 << 6)
45
46/* TGCR bit definitions */
47#define TIM12RS_UNRESET (1 << 0)
48#define TIM34RS_UNRESET (1 << 1)
49#define TIMMODE_64BIT_WDOG (2 << 2)
50
51/* WDTCR bit definitions */
52#define WDEN (1 << 14)
53#define WDFLAG (1 << 15)
54#define WDKEY_SEQ0 (0xa5c6 << 16)
55#define WDKEY_SEQ1 (0xda7e << 16)
56
f48f3cea 57static int heartbeat;
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58
59/*
60 * struct to hold data for each WDT device
61 * @base - base io address of WD device
62 * @clk - source clock of WDT
63 * @wdd - hold watchdog device as is in WDT core
64 */
65struct davinci_wdt_device {
66 void __iomem *base;
67 struct clk *clk;
68 struct watchdog_device wdd;
69};
7d831bf5 70
f48f3cea 71static int davinci_wdt_start(struct watchdog_device *wdd)
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72{
73 u32 tgcr;
74 u32 timer_margin;
9fd868f4 75 unsigned long wdt_freq;
6d9a6cf5 76 struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
9fd868f4 77
6d9a6cf5 78 wdt_freq = clk_get_rate(davinci_wdt->clk);
7d831bf5 79
7d831bf5 80 /* disable, internal clock source */
6d9a6cf5 81 iowrite32(0, davinci_wdt->base + TCR);
7d831bf5 82 /* reset timer, set mode to 64-bit watchdog, and unreset */
6d9a6cf5 83 iowrite32(0, davinci_wdt->base + TGCR);
7d831bf5 84 tgcr = TIMMODE_64BIT_WDOG | TIM12RS_UNRESET | TIM34RS_UNRESET;
6d9a6cf5 85 iowrite32(tgcr, davinci_wdt->base + TGCR);
7d831bf5 86 /* clear counter regs */
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87 iowrite32(0, davinci_wdt->base + TIM12);
88 iowrite32(0, davinci_wdt->base + TIM34);
7d831bf5 89 /* set timeout period */
f48f3cea 90 timer_margin = (((u64)wdd->timeout * wdt_freq) & 0xffffffff);
6d9a6cf5 91 iowrite32(timer_margin, davinci_wdt->base + PRD12);
f48f3cea 92 timer_margin = (((u64)wdd->timeout * wdt_freq) >> 32);
6d9a6cf5 93 iowrite32(timer_margin, davinci_wdt->base + PRD34);
7d831bf5 94 /* enable run continuously */
6d9a6cf5 95 iowrite32(ENAMODE12_PERIODIC, davinci_wdt->base + TCR);
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96 /* Once the WDT is in pre-active state write to
97 * TIM12, TIM34, PRD12, PRD34, TCR, TGCR, WDTCR are
98 * write protected (except for the WDKEY field)
99 */
100 /* put watchdog in pre-active state */
6d9a6cf5 101 iowrite32(WDKEY_SEQ0 | WDEN, davinci_wdt->base + WDTCR);
7d831bf5 102 /* put watchdog in active state */
6d9a6cf5 103 iowrite32(WDKEY_SEQ1 | WDEN, davinci_wdt->base + WDTCR);
f48f3cea 104 return 0;
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105}
106
f48f3cea 107static int davinci_wdt_ping(struct watchdog_device *wdd)
7d831bf5 108{
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109 struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
110
f48f3cea 111 /* put watchdog in service state */
6d9a6cf5 112 iowrite32(WDKEY_SEQ0, davinci_wdt->base + WDTCR);
f48f3cea 113 /* put watchdog in active state */
6d9a6cf5 114 iowrite32(WDKEY_SEQ1, davinci_wdt->base + WDTCR);
f48f3cea 115 return 0;
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116}
117
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118static unsigned int davinci_wdt_get_timeleft(struct watchdog_device *wdd)
119{
120 u64 timer_counter;
121 unsigned long freq;
122 u32 val;
123 struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
124
125 /* if timeout has occured then return 0 */
126 val = ioread32(davinci_wdt->base + WDTCR);
127 if (val & WDFLAG)
128 return 0;
129
130 freq = clk_get_rate(davinci_wdt->clk);
131
132 if (!freq)
133 return 0;
134
135 timer_counter = ioread32(davinci_wdt->base + TIM12);
136 timer_counter |= ((u64)ioread32(davinci_wdt->base + TIM34) << 32);
137
138 do_div(timer_counter, freq);
139
140 return wdd->timeout - timer_counter;
141}
142
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143static int davinci_wdt_restart(struct watchdog_device *wdd,
144 unsigned long action, void *data)
145{
146 struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
147 u32 tgcr, wdtcr;
148
149 /* disable, internal clock source */
150 iowrite32(0, davinci_wdt->base + TCR);
151
152 /* reset timer, set mode to 64-bit watchdog, and unreset */
153 tgcr = 0;
154 iowrite32(tgcr, davinci_wdt->base + TGCR);
155 tgcr = TIMMODE_64BIT_WDOG | TIM12RS_UNRESET | TIM34RS_UNRESET;
156 iowrite32(tgcr, davinci_wdt->base + TGCR);
157
158 /* clear counter and period regs */
159 iowrite32(0, davinci_wdt->base + TIM12);
160 iowrite32(0, davinci_wdt->base + TIM34);
161 iowrite32(0, davinci_wdt->base + PRD12);
162 iowrite32(0, davinci_wdt->base + PRD34);
163
164 /* put watchdog in pre-active state */
165 wdtcr = WDKEY_SEQ0 | WDEN;
166 iowrite32(wdtcr, davinci_wdt->base + WDTCR);
167
168 /* put watchdog in active state */
169 wdtcr = WDKEY_SEQ1 | WDEN;
170 iowrite32(wdtcr, davinci_wdt->base + WDTCR);
171
172 /* write an invalid value to the WDKEY field to trigger a restart */
173 wdtcr = 0x00004000;
174 iowrite32(wdtcr, davinci_wdt->base + WDTCR);
175
176 return 0;
177}
178
f48f3cea 179static const struct watchdog_info davinci_wdt_info = {
f1a08cc9 180 .options = WDIOF_KEEPALIVEPING,
8832b200 181 .identity = "DaVinci/Keystone Watchdog",
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182};
183
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184static const struct watchdog_ops davinci_wdt_ops = {
185 .owner = THIS_MODULE,
186 .start = davinci_wdt_start,
187 .stop = davinci_wdt_ping,
188 .ping = davinci_wdt_ping,
a7719949 189 .get_timeleft = davinci_wdt_get_timeleft,
71d1f058 190 .restart = davinci_wdt_restart,
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191};
192
2d991a16 193static int davinci_wdt_probe(struct platform_device *pdev)
7d831bf5 194{
e20880e6 195 int ret = 0;
371d3525 196 struct device *dev = &pdev->dev;
e20880e6 197 struct resource *wdt_mem;
f48f3cea 198 struct watchdog_device *wdd;
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199 struct davinci_wdt_device *davinci_wdt;
200
201 davinci_wdt = devm_kzalloc(dev, sizeof(*davinci_wdt), GFP_KERNEL);
202 if (!davinci_wdt)
203 return -ENOMEM;
7d831bf5 204
6d9a6cf5 205 davinci_wdt->clk = devm_clk_get(dev, NULL);
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206
207 if (IS_ERR(davinci_wdt->clk)) {
208 if (PTR_ERR(davinci_wdt->clk) != -EPROBE_DEFER)
209 dev_err(&pdev->dev, "failed to get clock node\n");
6d9a6cf5 210 return PTR_ERR(davinci_wdt->clk);
9b386574 211 }
9fd868f4 212
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213 ret = clk_prepare_enable(davinci_wdt->clk);
214 if (ret) {
215 dev_err(&pdev->dev, "failed to prepare clock\n");
216 return ret;
217 }
9fd868f4 218
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219 platform_set_drvdata(pdev, davinci_wdt);
220
221 wdd = &davinci_wdt->wdd;
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222 wdd->info = &davinci_wdt_info;
223 wdd->ops = &davinci_wdt_ops;
224 wdd->min_timeout = 1;
225 wdd->max_timeout = MAX_HEARTBEAT;
226 wdd->timeout = DEFAULT_HEARTBEAT;
6551881c 227 wdd->parent = &pdev->dev;
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228
229 watchdog_init_timeout(wdd, heartbeat, dev);
230
231 dev_info(dev, "heartbeat %d sec\n", wdd->timeout);
7d831bf5 232
6d9a6cf5 233 watchdog_set_drvdata(wdd, davinci_wdt);
f48f3cea 234 watchdog_set_nowayout(wdd, 1);
71d1f058 235 watchdog_set_restart_priority(wdd, 128);
7d831bf5 236
f712eacf 237 wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
6d9a6cf5 238 davinci_wdt->base = devm_ioremap_resource(dev, wdt_mem);
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239 if (IS_ERR(davinci_wdt->base)) {
240 ret = PTR_ERR(davinci_wdt->base);
241 goto err_clk_disable;
242 }
7d831bf5 243
f48f3cea 244 ret = watchdog_register_device(wdd);
d66e5364 245 if (ret) {
f48f3cea 246 dev_err(dev, "cannot register watchdog device\n");
d66e5364 247 goto err_clk_disable;
737bcff5 248 }
7d831bf5 249
d66e5364
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250 return 0;
251
252err_clk_disable:
253 clk_disable_unprepare(davinci_wdt->clk);
254
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255 return ret;
256}
257
4b12b896 258static int davinci_wdt_remove(struct platform_device *pdev)
7d831bf5 259{
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260 struct davinci_wdt_device *davinci_wdt = platform_get_drvdata(pdev);
261
262 watchdog_unregister_device(&davinci_wdt->wdd);
263 clk_disable_unprepare(davinci_wdt->clk);
9fd868f4 264
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265 return 0;
266}
267
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268static const struct of_device_id davinci_wdt_of_match[] = {
269 { .compatible = "ti,davinci-wdt", },
270 {},
271};
272MODULE_DEVICE_TABLE(of, davinci_wdt_of_match);
273
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274static struct platform_driver platform_wdt_driver = {
275 .driver = {
84374812 276 .name = "davinci-wdt",
902e2e7d 277 .of_match_table = davinci_wdt_of_match,
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278 },
279 .probe = davinci_wdt_probe,
82268714 280 .remove = davinci_wdt_remove,
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281};
282
b8ec6118 283module_platform_driver(platform_wdt_driver);
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284
285MODULE_AUTHOR("Texas Instruments");
286MODULE_DESCRIPTION("DaVinci Watchdog Driver");
287
288module_param(heartbeat, int, 0);
289MODULE_PARM_DESC(heartbeat,
290 "Watchdog heartbeat period in seconds from 1 to "
291 __MODULE_STRING(MAX_HEARTBEAT) ", default "
292 __MODULE_STRING(DEFAULT_HEARTBEAT));
293
294MODULE_LICENSE("GPL");
84374812 295MODULE_ALIAS("platform:davinci-wdt");