1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Real time clock driver for DA9055
4 *
5 * Copyright(c) 2012 Dialog Semiconductor Ltd.
6 *
7 * Author: Dajun Dajun Chen <dajun.chen@diasemi.com>
8 */
9
10#include <linux/module.h>
11#include <linux/platform_device.h>
12#include <linux/rtc.h>
13
14#include <linux/mfd/da9055/core.h>
15#include <linux/mfd/da9055/reg.h>
16#include <linux/mfd/da9055/pdata.h>
17
18struct da9055_rtc {
19	struct rtc_device *rtc;
20	struct da9055 *da9055;
21	int alarm_enable;
22};
23
24static int da9055_rtc_enable_alarm(struct da9055_rtc *rtc, bool enable)
25{
26	int ret;
27	if (enable) {
28		ret = da9055_reg_update(rtc->da9055, DA9055_REG_ALARM_Y,
29					DA9055_RTC_ALM_EN,
30					DA9055_RTC_ALM_EN);
31		if (ret != 0)
32			dev_err(rtc->da9055->dev, "Failed to enable ALM: %d\n",
33				ret);
34		rtc->alarm_enable = 1;
35	} else {
36		ret = da9055_reg_update(rtc->da9055, DA9055_REG_ALARM_Y,
37					DA9055_RTC_ALM_EN, 0);
38		if (ret != 0)
39			dev_err(rtc->da9055->dev,
40				"Failed to disable ALM: %d\n", ret);
41		rtc->alarm_enable = 0;
42	}
43	return ret;
44}
45
46static irqreturn_t da9055_rtc_alm_irq(int irq, void *data)
47{
48	struct da9055_rtc *rtc = data;
49
50	da9055_rtc_enable_alarm(rtc, 0);
51	rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
52
53	return IRQ_HANDLED;
54}
55
56static int da9055_read_alarm(struct da9055 *da9055, struct rtc_time *rtc_tm)
57{
58	int ret;
59	uint8_t v[5];
60
61	ret = da9055_group_read(da9055, DA9055_REG_ALARM_MI, 5, v);
62	if (ret != 0) {
63		dev_err(da9055->dev, "Failed to group read ALM: %d\n", ret);
64		return ret;
65	}
66
67	rtc_tm->tm_year = (v[4] & DA9055_RTC_ALM_YEAR) + 100;
68	rtc_tm->tm_mon  = (v[3] & DA9055_RTC_ALM_MONTH) - 1;
69	rtc_tm->tm_mday = v[2] & DA9055_RTC_ALM_DAY;
70	rtc_tm->tm_hour = v[1] & DA9055_RTC_ALM_HOUR;
71	rtc_tm->tm_min  = v[0] & DA9055_RTC_ALM_MIN;
72	rtc_tm->tm_sec = 0;
73
74	return rtc_valid_tm(rtc_tm);
75}
76
77static int da9055_set_alarm(struct da9055 *da9055, struct rtc_time *rtc_tm)
78{
79	int ret;
80	uint8_t v[2];
81
82	rtc_tm->tm_year -= 100;
83	rtc_tm->tm_mon += 1;
84
85	ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MI,
86				DA9055_RTC_ALM_MIN, rtc_tm->tm_min);
87	if (ret != 0) {
88		dev_err(da9055->dev, "Failed to write ALRM MIN: %d\n", ret);
89		return ret;
90	}
91
92	v[0] = rtc_tm->tm_hour;
93	v[1] = rtc_tm->tm_mday;
94
95	ret = da9055_group_write(da9055, DA9055_REG_ALARM_H, 2, v);
96	if (ret < 0)
97		return ret;
98
99	ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MO,
100				DA9055_RTC_ALM_MONTH, rtc_tm->tm_mon);
101	if (ret < 0)
102		dev_err(da9055->dev, "Failed to write ALM Month:%d\n", ret);
103
104	ret = da9055_reg_update(da9055, DA9055_REG_ALARM_Y,
105				DA9055_RTC_ALM_YEAR, rtc_tm->tm_year);
106	if (ret < 0)
107		dev_err(da9055->dev, "Failed to write ALM Year:%d\n", ret);
108
109	return ret;
110}
111
112static int da9055_rtc_get_alarm_status(struct da9055 *da9055)
113{
114	int ret;
115
116	ret = da9055_reg_read(da9055, DA9055_REG_ALARM_Y);
117	if (ret < 0) {
118		dev_err(da9055->dev, "Failed to read ALM: %d\n", ret);
119		return ret;
120	}
121	ret &= DA9055_RTC_ALM_EN;
122	return (ret > 0) ? 1 : 0;
123}
124
125static int da9055_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
126{
127	struct da9055_rtc *rtc = dev_get_drvdata(dev);
128	uint8_t v[6];
129	int ret;
130
131	ret = da9055_reg_read(rtc->da9055, DA9055_REG_COUNT_S);
132	if (ret < 0)
133		return ret;
134
135	/*
136	 * Registers are only valid when RTC_READ
137	 * status bit is asserted
138	 */
139	if (!(ret & DA9055_RTC_READ))
140		return -EBUSY;
141
142	ret = da9055_group_read(rtc->da9055, DA9055_REG_COUNT_S, 6, v);
143	if (ret < 0) {
144		dev_err(rtc->da9055->dev, "Failed to read RTC time : %d\n",
145			ret);
146		return ret;
147	}
148
149	rtc_tm->tm_year = (v[5] & DA9055_RTC_YEAR) + 100;
150	rtc_tm->tm_mon  = (v[4] & DA9055_RTC_MONTH) - 1;
151	rtc_tm->tm_mday = v[3] & DA9055_RTC_DAY;
152	rtc_tm->tm_hour = v[2] & DA9055_RTC_HOUR;
153	rtc_tm->tm_min  = v[1] & DA9055_RTC_MIN;
154	rtc_tm->tm_sec  = v[0] & DA9055_RTC_SEC;
155
156	return 0;
157}
158
159static int da9055_rtc_set_time(struct device *dev, struct rtc_time *tm)
160{
161	struct da9055_rtc *rtc;
162	uint8_t v[6];
163
164	rtc = dev_get_drvdata(dev);
165
166	v[0] = tm->tm_sec;
167	v[1] = tm->tm_min;
168	v[2] = tm->tm_hour;
169	v[3] = tm->tm_mday;
170	v[4] = tm->tm_mon + 1;
171	v[5] = tm->tm_year - 100;
172
173	return da9055_group_write(rtc->da9055, DA9055_REG_COUNT_S, 6, v);
174}
175
176static int da9055_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
177{
178	int ret;
179	struct rtc_time *tm = &alrm->time;
180	struct da9055_rtc *rtc = dev_get_drvdata(dev);
181
182	ret = da9055_read_alarm(rtc->da9055, tm);
183
184	if (ret)
185		return ret;
186
187	alrm->enabled = da9055_rtc_get_alarm_status(rtc->da9055);
188
189	return 0;
190}
191
192static int da9055_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
193{
194	int ret;
195	struct rtc_time *tm = &alrm->time;
196	struct da9055_rtc *rtc = dev_get_drvdata(dev);
197
198	ret = da9055_rtc_enable_alarm(rtc, 0);
199	if (ret < 0)
200		return ret;
201
202	ret = da9055_set_alarm(rtc->da9055, tm);
203	if (ret)
204		return ret;
205
206	ret = da9055_rtc_enable_alarm(rtc, 1);
207
208	return ret;
209}
210
211static int da9055_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
212{
213	struct da9055_rtc *rtc = dev_get_drvdata(dev);
214
215	return da9055_rtc_enable_alarm(rtc, enabled);
216}
217
218static const struct rtc_class_ops da9055_rtc_ops = {
219	.read_time	= da9055_rtc_read_time,
220	.set_time	= da9055_rtc_set_time,
221	.read_alarm	= da9055_rtc_read_alarm,
222	.set_alarm	= da9055_rtc_set_alarm,
223	.alarm_irq_enable = da9055_rtc_alarm_irq_enable,
224};
225
226static int da9055_rtc_device_init(struct da9055 *da9055,
227					struct da9055_pdata *pdata)
228{
229	int ret;
230
231	/* Enable RTC and the internal Crystal */
232	ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
233				DA9055_RTC_EN, DA9055_RTC_EN);
234	if (ret < 0)
235		return ret;
236	ret = da9055_reg_update(da9055, DA9055_REG_EN_32K,
237				DA9055_CRYSTAL_EN, DA9055_CRYSTAL_EN);
238	if (ret < 0)
239		return ret;
240
241	/* Enable RTC in Power Down mode */
242	ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
243				DA9055_RTC_MODE_PD, DA9055_RTC_MODE_PD);
244	if (ret < 0)
245		return ret;
246
247	/* Enable RTC in Reset mode */
248	if (pdata && pdata->reset_enable) {
249		ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
250					DA9055_RTC_MODE_SD,
251					DA9055_RTC_MODE_SD <<
252					DA9055_RTC_MODE_SD_SHIFT);
253		if (ret < 0)
254			return ret;
255	}
256
257	/* Disable the RTC TICK ALM */
258	ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MO,
259				DA9055_RTC_TICK_WAKE_MASK, 0);
260	if (ret < 0)
261		return ret;
262
263	return 0;
264}
265
266static int da9055_rtc_probe(struct platform_device *pdev)
267{
268	struct da9055_rtc *rtc;
269	struct da9055_pdata *pdata = NULL;
270	int ret, alm_irq;
271
272	rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9055_rtc), GFP_KERNEL);
273	if (!rtc)
274		return -ENOMEM;
275
276	rtc->da9055 = dev_get_drvdata(pdev->dev.parent);
277	pdata = dev_get_platdata(rtc->da9055->dev);
278	platform_set_drvdata(pdev, rtc);
279
280	ret = da9055_rtc_device_init(rtc->da9055, pdata);
281	if (ret < 0)
282		goto err_rtc;
283
284	ret = da9055_reg_read(rtc->da9055, DA9055_REG_ALARM_Y);
285	if (ret < 0)
286		goto err_rtc;
287
288	if (ret & DA9055_RTC_ALM_EN)
289		rtc->alarm_enable = 1;
290
291	device_init_wakeup(&pdev->dev, 1);
292
293	rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
294					&da9055_rtc_ops, THIS_MODULE);
295	if (IS_ERR(rtc->rtc)) {
296		ret = PTR_ERR(rtc->rtc);
297		goto err_rtc;
298	}
299
300	alm_irq = platform_get_irq_byname(pdev, "ALM");
301	if (alm_irq < 0)
302		return alm_irq;
303
304	ret = devm_request_threaded_irq(&pdev->dev, alm_irq, NULL,
305					da9055_rtc_alm_irq,
306					IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
307					"ALM", rtc);
308	if (ret != 0)
309		dev_err(rtc->da9055->dev, "irq registration failed: %d\n", ret);
310
311err_rtc:
312	return ret;
313
314}
315
316#ifdef CONFIG_PM
317/* Turn off the alarm if it should not be a wake source. */
318static int da9055_rtc_suspend(struct device *dev)
319{
320	struct platform_device *pdev = to_platform_device(dev);
321	struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
322	int ret;
323
324	if (!device_may_wakeup(&pdev->dev)) {
325		/* Disable the ALM IRQ */
326		ret = da9055_rtc_enable_alarm(rtc, 0);
327		if (ret < 0)
328			dev_err(&pdev->dev, "Failed to disable RTC ALM\n");
329	}
330
331	return 0;
332}
333
334/* Enable the alarm if it should be enabled (in case it was disabled to
335 * prevent use as a wake source).
336 */
337static int da9055_rtc_resume(struct device *dev)
338{
339	struct platform_device *pdev = to_platform_device(dev);
340	struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
341	int ret;
342
343	if (!device_may_wakeup(&pdev->dev)) {
344		if (rtc->alarm_enable) {
345			ret = da9055_rtc_enable_alarm(rtc, 1);
346			if (ret < 0)
347				dev_err(&pdev->dev,
348					"Failed to restart RTC ALM\n");
349		}
350	}
351
352	return 0;
353}
354
355/* Unconditionally disable the alarm */
356static int da9055_rtc_freeze(struct device *dev)
357{
358	struct platform_device *pdev = to_platform_device(dev);
359	struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
360	int ret;
361
362	ret = da9055_rtc_enable_alarm(rtc, 0);
363	if (ret < 0)
364		dev_err(&pdev->dev, "Failed to freeze RTC ALMs\n");
365
366	return 0;
367
368}
369#else
370#define da9055_rtc_suspend NULL
371#define da9055_rtc_resume NULL
372#define da9055_rtc_freeze NULL
373#endif
374
375static const struct dev_pm_ops da9055_rtc_pm_ops = {
376	.suspend = da9055_rtc_suspend,
377	.resume = da9055_rtc_resume,
378
379	.freeze = da9055_rtc_freeze,
380	.thaw = da9055_rtc_resume,
381	.restore = da9055_rtc_resume,
382
383	.poweroff = da9055_rtc_suspend,
384};
385
386static struct platform_driver da9055_rtc_driver = {
387	.probe  = da9055_rtc_probe,
388	.driver = {
389		.name   = "da9055-rtc",
390		.pm = &da9055_rtc_pm_ops,
391	},
392};
393
394module_platform_driver(da9055_rtc_driver);
395
396MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
397MODULE_DESCRIPTION("RTC driver for Dialog DA9055 PMIC");
398MODULE_LICENSE("GPL");
399MODULE_ALIAS("platform:da9055-rtc");
400