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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Freescale STMP37XX/STMP378X Real Time Clock driver
4 *
5 * Copyright (c) 2007 Sigmatel, Inc.
6 * Peter Hartley, <peter.hartley@sigmatel.com>
7 *
8 * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
9 * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
10 * Copyright 2011 Wolfram Sang, Pengutronix e.K.
11 */
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/io.h>
15#include <linux/init.h>
16#include <linux/platform_device.h>
17#include <linux/interrupt.h>
18#include <linux/delay.h>
19#include <linux/rtc.h>
20#include <linux/slab.h>
21#include <linux/of_device.h>
22#include <linux/of.h>
23#include <linux/stmp_device.h>
24#include <linux/stmp3xxx_rtc_wdt.h>
25
26#define STMP3XXX_RTC_CTRL 0x0
27#define STMP3XXX_RTC_CTRL_ALARM_IRQ_EN 0x00000001
28#define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN 0x00000002
29#define STMP3XXX_RTC_CTRL_ALARM_IRQ 0x00000004
30#define STMP3XXX_RTC_CTRL_WATCHDOGEN 0x00000010
31
32#define STMP3XXX_RTC_STAT 0x10
33#define STMP3XXX_RTC_STAT_STALE_SHIFT 16
34#define STMP3XXX_RTC_STAT_RTC_PRESENT 0x80000000
35#define STMP3XXX_RTC_STAT_XTAL32000_PRESENT 0x10000000
36#define STMP3XXX_RTC_STAT_XTAL32768_PRESENT 0x08000000
37
38#define STMP3XXX_RTC_SECONDS 0x30
39
40#define STMP3XXX_RTC_ALARM 0x40
41
42#define STMP3XXX_RTC_WATCHDOG 0x50
43
44#define STMP3XXX_RTC_PERSISTENT0 0x60
45#define STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE (1 << 0)
46#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN (1 << 1)
47#define STMP3XXX_RTC_PERSISTENT0_ALARM_EN (1 << 2)
48#define STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP (1 << 4)
49#define STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP (1 << 5)
50#define STMP3XXX_RTC_PERSISTENT0_XTAL32_FREQ (1 << 6)
51#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE (1 << 7)
52
53#define STMP3XXX_RTC_PERSISTENT1 0x70
54/* missing bitmask in headers */
55#define STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER 0x80000000
56
57struct stmp3xxx_rtc_data {
58 struct rtc_device *rtc;
59 void __iomem *io;
60 int irq_alarm;
61};
62
63#if IS_ENABLED(CONFIG_STMP3XXX_RTC_WATCHDOG)
64/**
65 * stmp3xxx_wdt_set_timeout - configure the watchdog inside the STMP3xxx RTC
66 * @dev: the parent device of the watchdog (= the RTC)
67 * @timeout: the desired value for the timeout register of the watchdog.
68 * 0 disables the watchdog
69 *
70 * The watchdog needs one register and two bits which are in the RTC domain.
71 * To handle the resource conflict, the RTC driver will create another
72 * platform_device for the watchdog driver as a child of the RTC device.
73 * The watchdog driver is passed the below accessor function via platform_data
74 * to configure the watchdog. Locking is not needed because accessing SET/CLR
75 * registers is atomic.
76 */
77
78static void stmp3xxx_wdt_set_timeout(struct device *dev, u32 timeout)
79{
80 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
81
82 if (timeout) {
83 writel(timeout, rtc_data->io + STMP3XXX_RTC_WATCHDOG);
84 writel(STMP3XXX_RTC_CTRL_WATCHDOGEN,
85 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_SET);
86 writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER,
87 rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_SET);
88 } else {
89 writel(STMP3XXX_RTC_CTRL_WATCHDOGEN,
90 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
91 writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER,
92 rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_CLR);
93 }
94}
95
96static struct stmp3xxx_wdt_pdata wdt_pdata = {
97 .wdt_set_timeout = stmp3xxx_wdt_set_timeout,
98};
99
100static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev)
101{
102 int rc = -1;
103 struct platform_device *wdt_pdev =
104 platform_device_alloc("stmp3xxx_rtc_wdt", rtc_pdev->id);
105
106 if (wdt_pdev) {
107 wdt_pdev->dev.parent = &rtc_pdev->dev;
108 wdt_pdev->dev.platform_data = &wdt_pdata;
109 rc = platform_device_add(wdt_pdev);
110 }
111
112 if (rc)
113 dev_err(&rtc_pdev->dev,
114 "failed to register stmp3xxx_rtc_wdt\n");
115}
116#else
117static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev)
118{
119}
120#endif /* CONFIG_STMP3XXX_RTC_WATCHDOG */
121
122static int stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data)
123{
124 int timeout = 5000; /* 3ms according to i.MX28 Ref Manual */
125 /*
126 * The i.MX28 Applications Processor Reference Manual, Rev. 1, 2010
127 * states:
128 * | The order in which registers are updated is
129 * | Persistent 0, 1, 2, 3, 4, 5, Alarm, Seconds.
130 * | (This list is in bitfield order, from LSB to MSB, as they would
131 * | appear in the STALE_REGS and NEW_REGS bitfields of the HW_RTC_STAT
132 * | register. For example, the Seconds register corresponds to
133 * | STALE_REGS or NEW_REGS containing 0x80.)
134 */
135 do {
136 if (!(readl(rtc_data->io + STMP3XXX_RTC_STAT) &
137 (0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT)))
138 return 0;
139 udelay(1);
140 } while (--timeout > 0);
141 return (readl(rtc_data->io + STMP3XXX_RTC_STAT) &
142 (0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT)) ? -ETIME : 0;
143}
144
145/* Time read/write */
146static int stmp3xxx_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
147{
148 int ret;
149 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
150
151 ret = stmp3xxx_wait_time(rtc_data);
152 if (ret)
153 return ret;
154
155 rtc_time64_to_tm(readl(rtc_data->io + STMP3XXX_RTC_SECONDS), rtc_tm);
156 return 0;
157}
158
159static int stmp3xxx_rtc_settime(struct device *dev, struct rtc_time *rtc_tm)
160{
161 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
162
163 writel(rtc_tm_to_time64(rtc_tm), rtc_data->io + STMP3XXX_RTC_SECONDS);
164 return stmp3xxx_wait_time(rtc_data);
165}
166
167/* interrupt(s) handler */
168static irqreturn_t stmp3xxx_rtc_interrupt(int irq, void *dev_id)
169{
170 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev_id);
171 u32 status = readl(rtc_data->io + STMP3XXX_RTC_CTRL);
172
173 if (status & STMP3XXX_RTC_CTRL_ALARM_IRQ) {
174 writel(STMP3XXX_RTC_CTRL_ALARM_IRQ,
175 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
176 rtc_update_irq(rtc_data->rtc, 1, RTC_AF | RTC_IRQF);
177 return IRQ_HANDLED;
178 }
179
180 return IRQ_NONE;
181}
182
183static int stmp3xxx_alarm_irq_enable(struct device *dev, unsigned int enabled)
184{
185 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
186
187 if (enabled) {
188 writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
189 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
190 rtc_data->io + STMP3XXX_RTC_PERSISTENT0 +
191 STMP_OFFSET_REG_SET);
192 writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
193 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_SET);
194 } else {
195 writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
196 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
197 rtc_data->io + STMP3XXX_RTC_PERSISTENT0 +
198 STMP_OFFSET_REG_CLR);
199 writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
200 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
201 }
202 return 0;
203}
204
205static int stmp3xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
206{
207 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
208
209 rtc_time64_to_tm(readl(rtc_data->io + STMP3XXX_RTC_ALARM), &alm->time);
210 return 0;
211}
212
213static int stmp3xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
214{
215 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
216
217 writel(rtc_tm_to_time64(&alm->time), rtc_data->io + STMP3XXX_RTC_ALARM);
218
219 stmp3xxx_alarm_irq_enable(dev, alm->enabled);
220
221 return 0;
222}
223
224static const struct rtc_class_ops stmp3xxx_rtc_ops = {
225 .alarm_irq_enable =
226 stmp3xxx_alarm_irq_enable,
227 .read_time = stmp3xxx_rtc_gettime,
228 .set_time = stmp3xxx_rtc_settime,
229 .read_alarm = stmp3xxx_rtc_read_alarm,
230 .set_alarm = stmp3xxx_rtc_set_alarm,
231};
232
233static int stmp3xxx_rtc_remove(struct platform_device *pdev)
234{
235 struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(pdev);
236
237 if (!rtc_data)
238 return 0;
239
240 writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
241 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
242
243 return 0;
244}
245
246static int stmp3xxx_rtc_probe(struct platform_device *pdev)
247{
248 struct stmp3xxx_rtc_data *rtc_data;
249 struct resource *r;
250 u32 rtc_stat;
251 u32 pers0_set, pers0_clr;
252 u32 crystalfreq = 0;
253 int err;
254
255 rtc_data = devm_kzalloc(&pdev->dev, sizeof(*rtc_data), GFP_KERNEL);
256 if (!rtc_data)
257 return -ENOMEM;
258
259 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
260 if (!r) {
261 dev_err(&pdev->dev, "failed to get resource\n");
262 return -ENXIO;
263 }
264
265 rtc_data->io = devm_ioremap(&pdev->dev, r->start, resource_size(r));
266 if (!rtc_data->io) {
267 dev_err(&pdev->dev, "ioremap failed\n");
268 return -EIO;
269 }
270
271 rtc_data->irq_alarm = platform_get_irq(pdev, 0);
272
273 rtc_stat = readl(rtc_data->io + STMP3XXX_RTC_STAT);
274 if (!(rtc_stat & STMP3XXX_RTC_STAT_RTC_PRESENT)) {
275 dev_err(&pdev->dev, "no device onboard\n");
276 return -ENODEV;
277 }
278
279 platform_set_drvdata(pdev, rtc_data);
280
281 /*
282 * Resetting the rtc stops the watchdog timer that is potentially
283 * running. So (assuming it is running on purpose) don't reset if the
284 * watchdog is enabled.
285 */
286 if (readl(rtc_data->io + STMP3XXX_RTC_CTRL) &
287 STMP3XXX_RTC_CTRL_WATCHDOGEN) {
288 dev_info(&pdev->dev,
289 "Watchdog is running, skip resetting rtc\n");
290 } else {
291 err = stmp_reset_block(rtc_data->io);
292 if (err) {
293 dev_err(&pdev->dev, "stmp_reset_block failed: %d\n",
294 err);
295 return err;
296 }
297 }
298
299 /*
300 * Obviously the rtc needs a clock input to be able to run.
301 * This clock can be provided by an external 32k crystal. If that one is
302 * missing XTAL must not be disabled in suspend which consumes a
303 * lot of power. Normally the presence and exact frequency (supported
304 * are 32000 Hz and 32768 Hz) is detectable from fuses, but as reality
305 * proves these fuses are not blown correctly on all machines, so the
306 * frequency can be overridden in the device tree.
307 */
308 if (rtc_stat & STMP3XXX_RTC_STAT_XTAL32000_PRESENT)
309 crystalfreq = 32000;
310 else if (rtc_stat & STMP3XXX_RTC_STAT_XTAL32768_PRESENT)
311 crystalfreq = 32768;
312
313 of_property_read_u32(pdev->dev.of_node, "stmp,crystal-freq",
314 &crystalfreq);
315
316 switch (crystalfreq) {
317 case 32000:
318 /* keep 32kHz crystal running in low-power mode */
319 pers0_set = STMP3XXX_RTC_PERSISTENT0_XTAL32_FREQ |
320 STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP |
321 STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE;
322 pers0_clr = STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP;
323 break;
324 case 32768:
325 /* keep 32.768kHz crystal running in low-power mode */
326 pers0_set = STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP |
327 STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE;
328 pers0_clr = STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP |
329 STMP3XXX_RTC_PERSISTENT0_XTAL32_FREQ;
330 break;
331 default:
332 dev_warn(&pdev->dev,
333 "invalid crystal-freq specified in device-tree. Assuming no crystal\n");
334 fallthrough;
335 case 0:
336 /* keep XTAL on in low-power mode */
337 pers0_set = STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP;
338 pers0_clr = STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP |
339 STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE;
340 }
341
342 writel(pers0_set, rtc_data->io + STMP3XXX_RTC_PERSISTENT0 +
343 STMP_OFFSET_REG_SET);
344
345 writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
346 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
347 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE | pers0_clr,
348 rtc_data->io + STMP3XXX_RTC_PERSISTENT0 + STMP_OFFSET_REG_CLR);
349
350 writel(STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN |
351 STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
352 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
353
354 rtc_data->rtc = devm_rtc_allocate_device(&pdev->dev);
355 if (IS_ERR(rtc_data->rtc))
356 return PTR_ERR(rtc_data->rtc);
357
358 err = devm_request_irq(&pdev->dev, rtc_data->irq_alarm,
359 stmp3xxx_rtc_interrupt, 0, "RTC alarm", &pdev->dev);
360 if (err) {
361 dev_err(&pdev->dev, "Cannot claim IRQ%d\n",
362 rtc_data->irq_alarm);
363 return err;
364 }
365
366 rtc_data->rtc->ops = &stmp3xxx_rtc_ops;
367 rtc_data->rtc->range_max = U32_MAX;
368
369 err = rtc_register_device(rtc_data->rtc);
370 if (err)
371 return err;
372
373 stmp3xxx_wdt_register(pdev);
374 return 0;
375}
376
377#ifdef CONFIG_PM_SLEEP
378static int stmp3xxx_rtc_suspend(struct device *dev)
379{
380 return 0;
381}
382
383static int stmp3xxx_rtc_resume(struct device *dev)
384{
385 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
386
387 stmp_reset_block(rtc_data->io);
388 writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
389 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
390 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE,
391 rtc_data->io + STMP3XXX_RTC_PERSISTENT0 + STMP_OFFSET_REG_CLR);
392 return 0;
393}
394#endif
395
396static SIMPLE_DEV_PM_OPS(stmp3xxx_rtc_pm_ops, stmp3xxx_rtc_suspend,
397 stmp3xxx_rtc_resume);
398
399static const struct of_device_id rtc_dt_ids[] = {
400 { .compatible = "fsl,stmp3xxx-rtc", },
401 { /* sentinel */ }
402};
403MODULE_DEVICE_TABLE(of, rtc_dt_ids);
404
405static struct platform_driver stmp3xxx_rtcdrv = {
406 .probe = stmp3xxx_rtc_probe,
407 .remove = stmp3xxx_rtc_remove,
408 .driver = {
409 .name = "stmp3xxx-rtc",
410 .pm = &stmp3xxx_rtc_pm_ops,
411 .of_match_table = rtc_dt_ids,
412 },
413};
414
415module_platform_driver(stmp3xxx_rtcdrv);
416
417MODULE_DESCRIPTION("STMP3xxx RTC Driver");
418MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com> and "
419 "Wolfram Sang <kernel@pengutronix.de>");
420MODULE_LICENSE("GPL");
1/*
2 * Freescale STMP37XX/STMP378X Real Time Clock driver
3 *
4 * Copyright (c) 2007 Sigmatel, Inc.
5 * Peter Hartley, <peter.hartley@sigmatel.com>
6 *
7 * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
8 * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
9 * Copyright 2011 Wolfram Sang, Pengutronix e.K.
10 */
11
12/*
13 * The code contained herein is licensed under the GNU General Public
14 * License. You may obtain a copy of the GNU General Public License
15 * Version 2 or later at the following locations:
16 *
17 * http://www.opensource.org/licenses/gpl-license.html
18 * http://www.gnu.org/copyleft/gpl.html
19 */
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/io.h>
23#include <linux/init.h>
24#include <linux/platform_device.h>
25#include <linux/interrupt.h>
26#include <linux/delay.h>
27#include <linux/rtc.h>
28#include <linux/slab.h>
29#include <linux/of_device.h>
30#include <linux/of.h>
31#include <linux/stmp_device.h>
32#include <linux/stmp3xxx_rtc_wdt.h>
33
34#define STMP3XXX_RTC_CTRL 0x0
35#define STMP3XXX_RTC_CTRL_ALARM_IRQ_EN 0x00000001
36#define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN 0x00000002
37#define STMP3XXX_RTC_CTRL_ALARM_IRQ 0x00000004
38#define STMP3XXX_RTC_CTRL_WATCHDOGEN 0x00000010
39
40#define STMP3XXX_RTC_STAT 0x10
41#define STMP3XXX_RTC_STAT_STALE_SHIFT 16
42#define STMP3XXX_RTC_STAT_RTC_PRESENT 0x80000000
43#define STMP3XXX_RTC_STAT_XTAL32000_PRESENT 0x10000000
44#define STMP3XXX_RTC_STAT_XTAL32768_PRESENT 0x08000000
45
46#define STMP3XXX_RTC_SECONDS 0x30
47
48#define STMP3XXX_RTC_ALARM 0x40
49
50#define STMP3XXX_RTC_WATCHDOG 0x50
51
52#define STMP3XXX_RTC_PERSISTENT0 0x60
53#define STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE (1 << 0)
54#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN (1 << 1)
55#define STMP3XXX_RTC_PERSISTENT0_ALARM_EN (1 << 2)
56#define STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP (1 << 4)
57#define STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP (1 << 5)
58#define STMP3XXX_RTC_PERSISTENT0_XTAL32_FREQ (1 << 6)
59#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE (1 << 7)
60
61#define STMP3XXX_RTC_PERSISTENT1 0x70
62/* missing bitmask in headers */
63#define STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER 0x80000000
64
65struct stmp3xxx_rtc_data {
66 struct rtc_device *rtc;
67 void __iomem *io;
68 int irq_alarm;
69};
70
71#if IS_ENABLED(CONFIG_STMP3XXX_RTC_WATCHDOG)
72/**
73 * stmp3xxx_wdt_set_timeout - configure the watchdog inside the STMP3xxx RTC
74 * @dev: the parent device of the watchdog (= the RTC)
75 * @timeout: the desired value for the timeout register of the watchdog.
76 * 0 disables the watchdog
77 *
78 * The watchdog needs one register and two bits which are in the RTC domain.
79 * To handle the resource conflict, the RTC driver will create another
80 * platform_device for the watchdog driver as a child of the RTC device.
81 * The watchdog driver is passed the below accessor function via platform_data
82 * to configure the watchdog. Locking is not needed because accessing SET/CLR
83 * registers is atomic.
84 */
85
86static void stmp3xxx_wdt_set_timeout(struct device *dev, u32 timeout)
87{
88 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
89
90 if (timeout) {
91 writel(timeout, rtc_data->io + STMP3XXX_RTC_WATCHDOG);
92 writel(STMP3XXX_RTC_CTRL_WATCHDOGEN,
93 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_SET);
94 writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER,
95 rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_SET);
96 } else {
97 writel(STMP3XXX_RTC_CTRL_WATCHDOGEN,
98 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
99 writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER,
100 rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_CLR);
101 }
102}
103
104static struct stmp3xxx_wdt_pdata wdt_pdata = {
105 .wdt_set_timeout = stmp3xxx_wdt_set_timeout,
106};
107
108static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev)
109{
110 int rc = -1;
111 struct platform_device *wdt_pdev =
112 platform_device_alloc("stmp3xxx_rtc_wdt", rtc_pdev->id);
113
114 if (wdt_pdev) {
115 wdt_pdev->dev.parent = &rtc_pdev->dev;
116 wdt_pdev->dev.platform_data = &wdt_pdata;
117 rc = platform_device_add(wdt_pdev);
118 }
119
120 if (rc)
121 dev_err(&rtc_pdev->dev,
122 "failed to register stmp3xxx_rtc_wdt\n");
123}
124#else
125static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev)
126{
127}
128#endif /* CONFIG_STMP3XXX_RTC_WATCHDOG */
129
130static int stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data)
131{
132 int timeout = 5000; /* 3ms according to i.MX28 Ref Manual */
133 /*
134 * The i.MX28 Applications Processor Reference Manual, Rev. 1, 2010
135 * states:
136 * | The order in which registers are updated is
137 * | Persistent 0, 1, 2, 3, 4, 5, Alarm, Seconds.
138 * | (This list is in bitfield order, from LSB to MSB, as they would
139 * | appear in the STALE_REGS and NEW_REGS bitfields of the HW_RTC_STAT
140 * | register. For example, the Seconds register corresponds to
141 * | STALE_REGS or NEW_REGS containing 0x80.)
142 */
143 do {
144 if (!(readl(rtc_data->io + STMP3XXX_RTC_STAT) &
145 (0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT)))
146 return 0;
147 udelay(1);
148 } while (--timeout > 0);
149 return (readl(rtc_data->io + STMP3XXX_RTC_STAT) &
150 (0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT)) ? -ETIME : 0;
151}
152
153/* Time read/write */
154static int stmp3xxx_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
155{
156 int ret;
157 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
158
159 ret = stmp3xxx_wait_time(rtc_data);
160 if (ret)
161 return ret;
162
163 rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_SECONDS), rtc_tm);
164 return 0;
165}
166
167static int stmp3xxx_rtc_set_mmss(struct device *dev, unsigned long t)
168{
169 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
170
171 writel(t, rtc_data->io + STMP3XXX_RTC_SECONDS);
172 return stmp3xxx_wait_time(rtc_data);
173}
174
175/* interrupt(s) handler */
176static irqreturn_t stmp3xxx_rtc_interrupt(int irq, void *dev_id)
177{
178 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev_id);
179 u32 status = readl(rtc_data->io + STMP3XXX_RTC_CTRL);
180
181 if (status & STMP3XXX_RTC_CTRL_ALARM_IRQ) {
182 writel(STMP3XXX_RTC_CTRL_ALARM_IRQ,
183 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
184 rtc_update_irq(rtc_data->rtc, 1, RTC_AF | RTC_IRQF);
185 return IRQ_HANDLED;
186 }
187
188 return IRQ_NONE;
189}
190
191static int stmp3xxx_alarm_irq_enable(struct device *dev, unsigned int enabled)
192{
193 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
194
195 if (enabled) {
196 writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
197 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
198 rtc_data->io + STMP3XXX_RTC_PERSISTENT0 +
199 STMP_OFFSET_REG_SET);
200 writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
201 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_SET);
202 } else {
203 writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
204 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
205 rtc_data->io + STMP3XXX_RTC_PERSISTENT0 +
206 STMP_OFFSET_REG_CLR);
207 writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
208 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
209 }
210 return 0;
211}
212
213static int stmp3xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
214{
215 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
216
217 rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_ALARM), &alm->time);
218 return 0;
219}
220
221static int stmp3xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
222{
223 unsigned long t;
224 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
225
226 rtc_tm_to_time(&alm->time, &t);
227 writel(t, rtc_data->io + STMP3XXX_RTC_ALARM);
228
229 stmp3xxx_alarm_irq_enable(dev, alm->enabled);
230
231 return 0;
232}
233
234static const struct rtc_class_ops stmp3xxx_rtc_ops = {
235 .alarm_irq_enable =
236 stmp3xxx_alarm_irq_enable,
237 .read_time = stmp3xxx_rtc_gettime,
238 .set_mmss = stmp3xxx_rtc_set_mmss,
239 .read_alarm = stmp3xxx_rtc_read_alarm,
240 .set_alarm = stmp3xxx_rtc_set_alarm,
241};
242
243static int stmp3xxx_rtc_remove(struct platform_device *pdev)
244{
245 struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(pdev);
246
247 if (!rtc_data)
248 return 0;
249
250 writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
251 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
252
253 return 0;
254}
255
256static int stmp3xxx_rtc_probe(struct platform_device *pdev)
257{
258 struct stmp3xxx_rtc_data *rtc_data;
259 struct resource *r;
260 u32 rtc_stat;
261 u32 pers0_set, pers0_clr;
262 u32 crystalfreq = 0;
263 int err;
264
265 rtc_data = devm_kzalloc(&pdev->dev, sizeof(*rtc_data), GFP_KERNEL);
266 if (!rtc_data)
267 return -ENOMEM;
268
269 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
270 if (!r) {
271 dev_err(&pdev->dev, "failed to get resource\n");
272 return -ENXIO;
273 }
274
275 rtc_data->io = devm_ioremap(&pdev->dev, r->start, resource_size(r));
276 if (!rtc_data->io) {
277 dev_err(&pdev->dev, "ioremap failed\n");
278 return -EIO;
279 }
280
281 rtc_data->irq_alarm = platform_get_irq(pdev, 0);
282
283 rtc_stat = readl(rtc_data->io + STMP3XXX_RTC_STAT);
284 if (!(rtc_stat & STMP3XXX_RTC_STAT_RTC_PRESENT)) {
285 dev_err(&pdev->dev, "no device onboard\n");
286 return -ENODEV;
287 }
288
289 platform_set_drvdata(pdev, rtc_data);
290
291 err = stmp_reset_block(rtc_data->io);
292 if (err) {
293 dev_err(&pdev->dev, "stmp_reset_block failed: %d\n", err);
294 return err;
295 }
296
297 /*
298 * Obviously the rtc needs a clock input to be able to run.
299 * This clock can be provided by an external 32k crystal. If that one is
300 * missing XTAL must not be disabled in suspend which consumes a
301 * lot of power. Normally the presence and exact frequency (supported
302 * are 32000 Hz and 32768 Hz) is detectable from fuses, but as reality
303 * proves these fuses are not blown correctly on all machines, so the
304 * frequency can be overridden in the device tree.
305 */
306 if (rtc_stat & STMP3XXX_RTC_STAT_XTAL32000_PRESENT)
307 crystalfreq = 32000;
308 else if (rtc_stat & STMP3XXX_RTC_STAT_XTAL32768_PRESENT)
309 crystalfreq = 32768;
310
311 of_property_read_u32(pdev->dev.of_node, "stmp,crystal-freq",
312 &crystalfreq);
313
314 switch (crystalfreq) {
315 case 32000:
316 /* keep 32kHz crystal running in low-power mode */
317 pers0_set = STMP3XXX_RTC_PERSISTENT0_XTAL32_FREQ |
318 STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP |
319 STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE;
320 pers0_clr = STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP;
321 break;
322 case 32768:
323 /* keep 32.768kHz crystal running in low-power mode */
324 pers0_set = STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP |
325 STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE;
326 pers0_clr = STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP |
327 STMP3XXX_RTC_PERSISTENT0_XTAL32_FREQ;
328 break;
329 default:
330 dev_warn(&pdev->dev,
331 "invalid crystal-freq specified in device-tree. Assuming no crystal\n");
332 /* fall-through */
333 case 0:
334 /* keep XTAL on in low-power mode */
335 pers0_set = STMP3XXX_RTC_PERSISTENT0_XTAL24MHZ_PWRUP;
336 pers0_clr = STMP3XXX_RTC_PERSISTENT0_XTAL32KHZ_PWRUP |
337 STMP3XXX_RTC_PERSISTENT0_CLOCKSOURCE;
338 }
339
340 writel(pers0_set, rtc_data->io + STMP3XXX_RTC_PERSISTENT0 +
341 STMP_OFFSET_REG_SET);
342
343 writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
344 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
345 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE | pers0_clr,
346 rtc_data->io + STMP3XXX_RTC_PERSISTENT0 + STMP_OFFSET_REG_CLR);
347
348 writel(STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN |
349 STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
350 rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
351
352 rtc_data->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
353 &stmp3xxx_rtc_ops, THIS_MODULE);
354 if (IS_ERR(rtc_data->rtc))
355 return PTR_ERR(rtc_data->rtc);
356
357 err = devm_request_irq(&pdev->dev, rtc_data->irq_alarm,
358 stmp3xxx_rtc_interrupt, 0, "RTC alarm", &pdev->dev);
359 if (err) {
360 dev_err(&pdev->dev, "Cannot claim IRQ%d\n",
361 rtc_data->irq_alarm);
362 return err;
363 }
364
365 stmp3xxx_wdt_register(pdev);
366 return 0;
367}
368
369#ifdef CONFIG_PM_SLEEP
370static int stmp3xxx_rtc_suspend(struct device *dev)
371{
372 return 0;
373}
374
375static int stmp3xxx_rtc_resume(struct device *dev)
376{
377 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
378
379 stmp_reset_block(rtc_data->io);
380 writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
381 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
382 STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE,
383 rtc_data->io + STMP3XXX_RTC_PERSISTENT0 + STMP_OFFSET_REG_CLR);
384 return 0;
385}
386#endif
387
388static SIMPLE_DEV_PM_OPS(stmp3xxx_rtc_pm_ops, stmp3xxx_rtc_suspend,
389 stmp3xxx_rtc_resume);
390
391static const struct of_device_id rtc_dt_ids[] = {
392 { .compatible = "fsl,stmp3xxx-rtc", },
393 { /* sentinel */ }
394};
395MODULE_DEVICE_TABLE(of, rtc_dt_ids);
396
397static struct platform_driver stmp3xxx_rtcdrv = {
398 .probe = stmp3xxx_rtc_probe,
399 .remove = stmp3xxx_rtc_remove,
400 .driver = {
401 .name = "stmp3xxx-rtc",
402 .pm = &stmp3xxx_rtc_pm_ops,
403 .of_match_table = rtc_dt_ids,
404 },
405};
406
407module_platform_driver(stmp3xxx_rtcdrv);
408
409MODULE_DESCRIPTION("STMP3xxx RTC Driver");
410MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com> and "
411 "Wolfram Sang <w.sang@pengutronix.de>");
412MODULE_LICENSE("GPL");