1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
|
/*
* Freescale STMP37XX/STMP378X Real Time Clock driver
*
* Copyright (c) 2007 Sigmatel, Inc.
* Peter Hartley, <peter.hartley@sigmatel.com>
*
* Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
* Copyright 2011 Wolfram Sang, Pengutronix e.K.
*/
/*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/of_device.h>
#include <linux/of.h>
#include <linux/stmp_device.h>
#include <linux/stmp3xxx_rtc_wdt.h>
#define STMP3XXX_RTC_CTRL 0x0
#define STMP3XXX_RTC_CTRL_SET 0x4
#define STMP3XXX_RTC_CTRL_CLR 0x8
#define STMP3XXX_RTC_CTRL_ALARM_IRQ_EN 0x00000001
#define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN 0x00000002
#define STMP3XXX_RTC_CTRL_ALARM_IRQ 0x00000004
#define STMP3XXX_RTC_CTRL_WATCHDOGEN 0x00000010
#define STMP3XXX_RTC_STAT 0x10
#define STMP3XXX_RTC_STAT_STALE_SHIFT 16
#define STMP3XXX_RTC_STAT_RTC_PRESENT 0x80000000
#define STMP3XXX_RTC_SECONDS 0x30
#define STMP3XXX_RTC_ALARM 0x40
#define STMP3XXX_RTC_WATCHDOG 0x50
#define STMP3XXX_RTC_PERSISTENT0 0x60
#define STMP3XXX_RTC_PERSISTENT0_SET 0x64
#define STMP3XXX_RTC_PERSISTENT0_CLR 0x68
#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN 0x00000002
#define STMP3XXX_RTC_PERSISTENT0_ALARM_EN 0x00000004
#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE 0x00000080
#define STMP3XXX_RTC_PERSISTENT1 0x70
/* missing bitmask in headers */
#define STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER 0x80000000
struct stmp3xxx_rtc_data {
struct rtc_device *rtc;
void __iomem *io;
int irq_alarm;
};
#if IS_ENABLED(CONFIG_STMP3XXX_RTC_WATCHDOG)
/**
* stmp3xxx_wdt_set_timeout - configure the watchdog inside the STMP3xxx RTC
* @dev: the parent device of the watchdog (= the RTC)
* @timeout: the desired value for the timeout register of the watchdog.
* 0 disables the watchdog
*
* The watchdog needs one register and two bits which are in the RTC domain.
* To handle the resource conflict, the RTC driver will create another
* platform_device for the watchdog driver as a child of the RTC device.
* The watchdog driver is passed the below accessor function via platform_data
* to configure the watchdog. Locking is not needed because accessing SET/CLR
* registers is atomic.
*/
static void stmp3xxx_wdt_set_timeout(struct device *dev, u32 timeout)
{
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
if (timeout) {
writel(timeout, rtc_data->io + STMP3XXX_RTC_WATCHDOG);
writel(STMP3XXX_RTC_CTRL_WATCHDOGEN,
rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_SET);
writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER,
rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_SET);
} else {
writel(STMP3XXX_RTC_CTRL_WATCHDOGEN,
rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER,
rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_CLR);
}
}
static struct stmp3xxx_wdt_pdata wdt_pdata = {
.wdt_set_timeout = stmp3xxx_wdt_set_timeout,
};
static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev)
{
struct platform_device *wdt_pdev =
platform_device_alloc("stmp3xxx_rtc_wdt", rtc_pdev->id);
if (wdt_pdev) {
wdt_pdev->dev.parent = &rtc_pdev->dev;
wdt_pdev->dev.platform_data = &wdt_pdata;
platform_device_add(wdt_pdev);
}
}
#else
static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev)
{
}
#endif /* CONFIG_STMP3XXX_RTC_WATCHDOG */
static void stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data)
{
/*
* The datasheet doesn't say which way round the
* NEW_REGS/STALE_REGS bitfields go. In fact it's 0x1=P0,
* 0x2=P1, .., 0x20=P5, 0x40=ALARM, 0x80=SECONDS
*/
while (readl(rtc_data->io + STMP3XXX_RTC_STAT) &
(0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT))
cpu_relax();
}
/* Time read/write */
static int stmp3xxx_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
{
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
stmp3xxx_wait_time(rtc_data);
rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_SECONDS), rtc_tm);
return 0;
}
static int stmp3xxx_rtc_set_mmss(struct device *dev, unsigned long t)
{
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
writel(t, rtc_data->io + STMP3XXX_RTC_SECONDS);
stmp3xxx_wait_time(rtc_data);
return 0;
}
/* interrupt(s) handler */
static irqreturn_t stmp3xxx_rtc_interrupt(int irq, void *dev_id)
{
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev_id);
u32 status = readl(rtc_data->io + STMP3XXX_RTC_CTRL);
if (status & STMP3XXX_RTC_CTRL_ALARM_IRQ) {
writel(STMP3XXX_RTC_CTRL_ALARM_IRQ,
rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
rtc_update_irq(rtc_data->rtc, 1, RTC_AF | RTC_IRQF);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static int stmp3xxx_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
if (enabled) {
writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
rtc_data->io + STMP3XXX_RTC_PERSISTENT0_SET);
writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
rtc_data->io + STMP3XXX_RTC_CTRL_SET);
} else {
writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR);
writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
}
return 0;
}
static int stmp3xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_ALARM), &alm->time);
return 0;
}
static int stmp3xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
unsigned long t;
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
rtc_tm_to_time(&alm->time, &t);
writel(t, rtc_data->io + STMP3XXX_RTC_ALARM);
stmp3xxx_alarm_irq_enable(dev, alm->enabled);
return 0;
}
static struct rtc_class_ops stmp3xxx_rtc_ops = {
.alarm_irq_enable =
stmp3xxx_alarm_irq_enable,
.read_time = stmp3xxx_rtc_gettime,
.set_mmss = stmp3xxx_rtc_set_mmss,
.read_alarm = stmp3xxx_rtc_read_alarm,
.set_alarm = stmp3xxx_rtc_set_alarm,
};
static int stmp3xxx_rtc_remove(struct platform_device *pdev)
{
struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(pdev);
if (!rtc_data)
return 0;
writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
platform_set_drvdata(pdev, NULL);
return 0;
}
static int stmp3xxx_rtc_probe(struct platform_device *pdev)
{
struct stmp3xxx_rtc_data *rtc_data;
struct resource *r;
int err;
rtc_data = devm_kzalloc(&pdev->dev, sizeof(*rtc_data), GFP_KERNEL);
if (!rtc_data)
return -ENOMEM;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r) {
dev_err(&pdev->dev, "failed to get resource\n");
return -ENXIO;
}
rtc_data->io = devm_ioremap(&pdev->dev, r->start, resource_size(r));
if (!rtc_data->io) {
dev_err(&pdev->dev, "ioremap failed\n");
return -EIO;
}
rtc_data->irq_alarm = platform_get_irq(pdev, 0);
if (!(readl(STMP3XXX_RTC_STAT + rtc_data->io) &
STMP3XXX_RTC_STAT_RTC_PRESENT)) {
dev_err(&pdev->dev, "no device onboard\n");
return -ENODEV;
}
platform_set_drvdata(pdev, rtc_data);
stmp_reset_block(rtc_data->io);
writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE,
rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR);
writel(STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN |
STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
rtc_data->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
&stmp3xxx_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc_data->rtc)) {
err = PTR_ERR(rtc_data->rtc);
goto out;
}
err = devm_request_irq(&pdev->dev, rtc_data->irq_alarm,
stmp3xxx_rtc_interrupt, 0, "RTC alarm", &pdev->dev);
if (err) {
dev_err(&pdev->dev, "Cannot claim IRQ%d\n",
rtc_data->irq_alarm);
goto out;
}
stmp3xxx_wdt_register(pdev);
return 0;
out:
platform_set_drvdata(pdev, NULL);
return err;
}
#ifdef CONFIG_PM_SLEEP
static int stmp3xxx_rtc_suspend(struct device *dev)
{
return 0;
}
static int stmp3xxx_rtc_resume(struct device *dev)
{
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
stmp_reset_block(rtc_data->io);
writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE,
rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(stmp3xxx_rtc_pm_ops, stmp3xxx_rtc_suspend,
stmp3xxx_rtc_resume);
static const struct of_device_id rtc_dt_ids[] = {
{ .compatible = "fsl,stmp3xxx-rtc", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rtc_dt_ids);
static struct platform_driver stmp3xxx_rtcdrv = {
.probe = stmp3xxx_rtc_probe,
.remove = stmp3xxx_rtc_remove,
.driver = {
.name = "stmp3xxx-rtc",
.owner = THIS_MODULE,
.pm = &stmp3xxx_rtc_pm_ops,
.of_match_table = of_match_ptr(rtc_dt_ids),
},
};
module_platform_driver(stmp3xxx_rtcdrv);
MODULE_DESCRIPTION("STMP3xxx RTC Driver");
MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com> and "
"Wolfram Sang <w.sang@pengutronix.de>");
MODULE_LICENSE("GPL");
|
