watchdog: Convert to use devm_platform_ioremap_resource
[linux-block.git] / drivers / watchdog / davinci_wdt.c
CommitLineData
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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>
ac316725 16#include <linux/mod_devicetable.h>
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17#include <linux/types.h>
18#include <linux/kernel.h>
7d831bf5 19#include <linux/watchdog.h>
7d831bf5 20#include <linux/platform_device.h>
f78b0a8f 21#include <linux/io.h>
371d3525 22#include <linux/device.h>
9fd868f4 23#include <linux/clk.h>
6330c707 24#include <linux/err.h>
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25
26#define MODULE_NAME "DAVINCI-WDT: "
27
28#define DEFAULT_HEARTBEAT 60
29#define MAX_HEARTBEAT 600 /* really the max margin is 264/27MHz*/
30
31/* Timer register set definition */
32#define PID12 (0x0)
33#define EMUMGT (0x4)
34#define TIM12 (0x10)
35#define TIM34 (0x14)
36#define PRD12 (0x18)
37#define PRD34 (0x1C)
38#define TCR (0x20)
39#define TGCR (0x24)
40#define WDTCR (0x28)
41
42/* TCR bit definitions */
43#define ENAMODE12_DISABLED (0 << 6)
44#define ENAMODE12_ONESHOT (1 << 6)
45#define ENAMODE12_PERIODIC (2 << 6)
46
47/* TGCR bit definitions */
48#define TIM12RS_UNRESET (1 << 0)
49#define TIM34RS_UNRESET (1 << 1)
50#define TIMMODE_64BIT_WDOG (2 << 2)
51
52/* WDTCR bit definitions */
53#define WDEN (1 << 14)
54#define WDFLAG (1 << 15)
55#define WDKEY_SEQ0 (0xa5c6 << 16)
56#define WDKEY_SEQ1 (0xda7e << 16)
57
f48f3cea 58static int heartbeat;
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59
60/*
61 * struct to hold data for each WDT device
62 * @base - base io address of WD device
63 * @clk - source clock of WDT
64 * @wdd - hold watchdog device as is in WDT core
65 */
66struct davinci_wdt_device {
67 void __iomem *base;
68 struct clk *clk;
69 struct watchdog_device wdd;
70};
7d831bf5 71
f48f3cea 72static int davinci_wdt_start(struct watchdog_device *wdd)
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73{
74 u32 tgcr;
75 u32 timer_margin;
9fd868f4 76 unsigned long wdt_freq;
6d9a6cf5 77 struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
9fd868f4 78
6d9a6cf5 79 wdt_freq = clk_get_rate(davinci_wdt->clk);
7d831bf5 80
7d831bf5 81 /* disable, internal clock source */
6d9a6cf5 82 iowrite32(0, davinci_wdt->base + TCR);
7d831bf5 83 /* reset timer, set mode to 64-bit watchdog, and unreset */
6d9a6cf5 84 iowrite32(0, davinci_wdt->base + TGCR);
7d831bf5 85 tgcr = TIMMODE_64BIT_WDOG | TIM12RS_UNRESET | TIM34RS_UNRESET;
6d9a6cf5 86 iowrite32(tgcr, davinci_wdt->base + TGCR);
7d831bf5 87 /* clear counter regs */
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88 iowrite32(0, davinci_wdt->base + TIM12);
89 iowrite32(0, davinci_wdt->base + TIM34);
7d831bf5 90 /* set timeout period */
f48f3cea 91 timer_margin = (((u64)wdd->timeout * wdt_freq) & 0xffffffff);
6d9a6cf5 92 iowrite32(timer_margin, davinci_wdt->base + PRD12);
f48f3cea 93 timer_margin = (((u64)wdd->timeout * wdt_freq) >> 32);
6d9a6cf5 94 iowrite32(timer_margin, davinci_wdt->base + PRD34);
7d831bf5 95 /* enable run continuously */
6d9a6cf5 96 iowrite32(ENAMODE12_PERIODIC, davinci_wdt->base + TCR);
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97 /* Once the WDT is in pre-active state write to
98 * TIM12, TIM34, PRD12, PRD34, TCR, TGCR, WDTCR are
99 * write protected (except for the WDKEY field)
100 */
101 /* put watchdog in pre-active state */
6d9a6cf5 102 iowrite32(WDKEY_SEQ0 | WDEN, davinci_wdt->base + WDTCR);
7d831bf5 103 /* put watchdog in active state */
6d9a6cf5 104 iowrite32(WDKEY_SEQ1 | WDEN, davinci_wdt->base + WDTCR);
f48f3cea 105 return 0;
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106}
107
f48f3cea 108static int davinci_wdt_ping(struct watchdog_device *wdd)
7d831bf5 109{
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110 struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
111
f48f3cea 112 /* put watchdog in service state */
6d9a6cf5 113 iowrite32(WDKEY_SEQ0, davinci_wdt->base + WDTCR);
f48f3cea 114 /* put watchdog in active state */
6d9a6cf5 115 iowrite32(WDKEY_SEQ1, davinci_wdt->base + WDTCR);
f48f3cea 116 return 0;
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117}
118
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119static unsigned int davinci_wdt_get_timeleft(struct watchdog_device *wdd)
120{
121 u64 timer_counter;
122 unsigned long freq;
123 u32 val;
124 struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
125
126 /* if timeout has occured then return 0 */
127 val = ioread32(davinci_wdt->base + WDTCR);
128 if (val & WDFLAG)
129 return 0;
130
131 freq = clk_get_rate(davinci_wdt->clk);
132
133 if (!freq)
134 return 0;
135
136 timer_counter = ioread32(davinci_wdt->base + TIM12);
137 timer_counter |= ((u64)ioread32(davinci_wdt->base + TIM34) << 32);
138
139 do_div(timer_counter, freq);
140
141 return wdd->timeout - timer_counter;
142}
143
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144static int davinci_wdt_restart(struct watchdog_device *wdd,
145 unsigned long action, void *data)
146{
147 struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
148 u32 tgcr, wdtcr;
149
150 /* disable, internal clock source */
151 iowrite32(0, davinci_wdt->base + TCR);
152
153 /* reset timer, set mode to 64-bit watchdog, and unreset */
154 tgcr = 0;
155 iowrite32(tgcr, davinci_wdt->base + TGCR);
156 tgcr = TIMMODE_64BIT_WDOG | TIM12RS_UNRESET | TIM34RS_UNRESET;
157 iowrite32(tgcr, davinci_wdt->base + TGCR);
158
159 /* clear counter and period regs */
160 iowrite32(0, davinci_wdt->base + TIM12);
161 iowrite32(0, davinci_wdt->base + TIM34);
162 iowrite32(0, davinci_wdt->base + PRD12);
163 iowrite32(0, davinci_wdt->base + PRD34);
164
165 /* put watchdog in pre-active state */
166 wdtcr = WDKEY_SEQ0 | WDEN;
167 iowrite32(wdtcr, davinci_wdt->base + WDTCR);
168
169 /* put watchdog in active state */
170 wdtcr = WDKEY_SEQ1 | WDEN;
171 iowrite32(wdtcr, davinci_wdt->base + WDTCR);
172
173 /* write an invalid value to the WDKEY field to trigger a restart */
174 wdtcr = 0x00004000;
175 iowrite32(wdtcr, davinci_wdt->base + WDTCR);
176
177 return 0;
178}
179
f48f3cea 180static const struct watchdog_info davinci_wdt_info = {
f1a08cc9 181 .options = WDIOF_KEEPALIVEPING,
8832b200 182 .identity = "DaVinci/Keystone Watchdog",
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183};
184
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185static const struct watchdog_ops davinci_wdt_ops = {
186 .owner = THIS_MODULE,
187 .start = davinci_wdt_start,
188 .stop = davinci_wdt_ping,
189 .ping = davinci_wdt_ping,
a7719949 190 .get_timeleft = davinci_wdt_get_timeleft,
71d1f058 191 .restart = davinci_wdt_restart,
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192};
193
2d991a16 194static int davinci_wdt_probe(struct platform_device *pdev)
7d831bf5 195{
e20880e6 196 int ret = 0;
371d3525 197 struct device *dev = &pdev->dev;
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
0f0a6a28 237 davinci_wdt->base = devm_platform_ioremap_resource(pdev, 0);
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238 if (IS_ERR(davinci_wdt->base)) {
239 ret = PTR_ERR(davinci_wdt->base);
240 goto err_clk_disable;
241 }
7d831bf5 242
f48f3cea 243 ret = watchdog_register_device(wdd);
d66e5364 244 if (ret) {
f48f3cea 245 dev_err(dev, "cannot register watchdog device\n");
d66e5364 246 goto err_clk_disable;
737bcff5 247 }
7d831bf5 248
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249 return 0;
250
251err_clk_disable:
252 clk_disable_unprepare(davinci_wdt->clk);
253
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254 return ret;
255}
256
4b12b896 257static int davinci_wdt_remove(struct platform_device *pdev)
7d831bf5 258{
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259 struct davinci_wdt_device *davinci_wdt = platform_get_drvdata(pdev);
260
261 watchdog_unregister_device(&davinci_wdt->wdd);
262 clk_disable_unprepare(davinci_wdt->clk);
9fd868f4 263
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264 return 0;
265}
266
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267static const struct of_device_id davinci_wdt_of_match[] = {
268 { .compatible = "ti,davinci-wdt", },
269 {},
270};
271MODULE_DEVICE_TABLE(of, davinci_wdt_of_match);
272
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273static struct platform_driver platform_wdt_driver = {
274 .driver = {
84374812 275 .name = "davinci-wdt",
902e2e7d 276 .of_match_table = davinci_wdt_of_match,
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277 },
278 .probe = davinci_wdt_probe,
82268714 279 .remove = davinci_wdt_remove,
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280};
281
b8ec6118 282module_platform_driver(platform_wdt_driver);
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283
284MODULE_AUTHOR("Texas Instruments");
285MODULE_DESCRIPTION("DaVinci Watchdog Driver");
286
287module_param(heartbeat, int, 0);
288MODULE_PARM_DESC(heartbeat,
289 "Watchdog heartbeat period in seconds from 1 to "
290 __MODULE_STRING(MAX_HEARTBEAT) ", default "
291 __MODULE_STRING(DEFAULT_HEARTBEAT));
292
293MODULE_LICENSE("GPL");
84374812 294MODULE_ALIAS("platform:davinci-wdt");