1/*
2 * Real time clock driver for DA9052
3 *
4 * Copyright(c) 2012 Dialog Semiconductor Ltd.
5 *
6 * Author: Dajun Dajun Chen <dajun.chen@diasemi.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 */
14
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/rtc.h>
18#include <linux/err.h>
19
20#include <linux/mfd/da9052/da9052.h>
21#include <linux/mfd/da9052/reg.h>
22
23#define rtc_err(rtc, fmt, ...) \
24		dev_err(rtc->da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__)
25
26struct da9052_rtc {
27	struct rtc_device *rtc;
28	struct da9052 *da9052;
29};
30
31static int da9052_rtc_enable_alarm(struct da9052_rtc *rtc, bool enable)
32{
33	int ret;
34	if (enable) {
35		ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
36				DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON,
37				DA9052_ALARM_Y_ALARM_ON);
38		if (ret != 0)
39			rtc_err(rtc, "Failed to enable ALM: %d\n", ret);
40	} else {
41		ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
42			DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 0);
43		if (ret != 0)
44			rtc_err(rtc, "Write error: %d\n", ret);
45	}
46	return ret;
47}
48
49static irqreturn_t da9052_rtc_irq(int irq, void *data)
50{
51	struct da9052_rtc *rtc = data;
52
53	rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
54
55	return IRQ_HANDLED;
56}
57
58static int da9052_read_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
59{
60	int ret;
61	uint8_t v[5];
62
63	ret = da9052_group_read(rtc->da9052, DA9052_ALARM_MI_REG, 5, v);
64	if (ret != 0) {
65		rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
66		return ret;
67	}
68
69	rtc_tm->tm_year = (v[4] & DA9052_RTC_YEAR) + 100;
70	rtc_tm->tm_mon  = (v[3] & DA9052_RTC_MONTH) - 1;
71	rtc_tm->tm_mday = v[2] & DA9052_RTC_DAY;
72	rtc_tm->tm_hour = v[1] & DA9052_RTC_HOUR;
73	rtc_tm->tm_min  = v[0] & DA9052_RTC_MIN;
74
75	ret = rtc_valid_tm(rtc_tm);
76	return ret;
77}
78
79static int da9052_set_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
80{
81	struct da9052 *da9052 = rtc->da9052;
82	unsigned long alm_time;
83	int ret;
84	uint8_t v[3];
85
86	ret = rtc_tm_to_time(rtc_tm, &alm_time);
87	if (ret != 0)
88		return ret;
89
90	if (rtc_tm->tm_sec > 0) {
91		alm_time += 60 - rtc_tm->tm_sec;
92		rtc_time_to_tm(alm_time, rtc_tm);
93	}
94	BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */
95
96	rtc_tm->tm_year -= 100;
97	rtc_tm->tm_mon += 1;
98
99	ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG,
100				DA9052_RTC_MIN, rtc_tm->tm_min);
101	if (ret != 0) {
102		rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret);
103		return ret;
104	}
105
106	v[0] = rtc_tm->tm_hour;
107	v[1] = rtc_tm->tm_mday;
108	v[2] = rtc_tm->tm_mon;
109
110	ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v);
111	if (ret < 0)
112		return ret;
113
114	ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
115				DA9052_RTC_YEAR, rtc_tm->tm_year);
116	if (ret != 0)
117		rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret);
118
119	return ret;
120}
121
122static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc)
123{
124	int ret;
125
126	ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG);
127	if (ret < 0) {
128		rtc_err(rtc, "Failed to read ALM: %d\n", ret);
129		return ret;
130	}
131
132	return !!(ret&DA9052_ALARM_Y_ALARM_ON);
133}
134
135static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
136{
137	struct da9052_rtc *rtc = dev_get_drvdata(dev);
138	uint8_t v[6];
139	int ret;
140
141	ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
142	if (ret < 0) {
143		rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
144		return ret;
145	}
146
147	rtc_tm->tm_year = (v[5] & DA9052_RTC_YEAR) + 100;
148	rtc_tm->tm_mon  = (v[4] & DA9052_RTC_MONTH) - 1;
149	rtc_tm->tm_mday = v[3] & DA9052_RTC_DAY;
150	rtc_tm->tm_hour = v[2] & DA9052_RTC_HOUR;
151	rtc_tm->tm_min  = v[1] & DA9052_RTC_MIN;
152	rtc_tm->tm_sec  = v[0] & DA9052_RTC_SEC;
153
154	ret = rtc_valid_tm(rtc_tm);
155	return ret;
156}
157
158static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm)
159{
160	struct da9052_rtc *rtc;
161	uint8_t v[6];
162	int ret;
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	ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
174	if (ret < 0)
175		rtc_err(rtc, "failed to set RTC time: %d\n", ret);
176	return ret;
177}
178
179static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
180{
181	int ret;
182	struct rtc_time *tm = &alrm->time;
183	struct da9052_rtc *rtc = dev_get_drvdata(dev);
184
185	ret = da9052_read_alarm(rtc, tm);
186	if (ret < 0) {
187		rtc_err(rtc, "failed to read RTC alarm: %d\n", ret);
188		return ret;
189	}
190
191	alrm->enabled = da9052_rtc_get_alarm_status(rtc);
192	return 0;
193}
194
195static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
196{
197	int ret;
198	struct rtc_time *tm = &alrm->time;
199	struct da9052_rtc *rtc = dev_get_drvdata(dev);
200
201	ret = da9052_rtc_enable_alarm(rtc, 0);
202	if (ret < 0)
203		return ret;
204
205	ret = da9052_set_alarm(rtc, tm);
206	if (ret < 0)
207		return ret;
208
209	ret = da9052_rtc_enable_alarm(rtc, 1);
210	return ret;
211}
212
213static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
214{
215	struct da9052_rtc *rtc = dev_get_drvdata(dev);
216
217	return da9052_rtc_enable_alarm(rtc, enabled);
218}
219
220static const struct rtc_class_ops da9052_rtc_ops = {
221	.read_time	= da9052_rtc_read_time,
222	.set_time	= da9052_rtc_set_time,
223	.read_alarm	= da9052_rtc_read_alarm,
224	.set_alarm	= da9052_rtc_set_alarm,
225	.alarm_irq_enable = da9052_rtc_alarm_irq_enable,
226};
227
228static int da9052_rtc_probe(struct platform_device *pdev)
229{
230	struct da9052_rtc *rtc;
231	int ret;
232
233	rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL);
234	if (!rtc)
235		return -ENOMEM;
236
237	rtc->da9052 = dev_get_drvdata(pdev->dev.parent);
238	platform_set_drvdata(pdev, rtc);
239
240	ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE);
241	if (ret < 0) {
242		rtc_err(rtc,
243			"Failed to setup RTC battery charging: %d\n", ret);
244		return ret;
245	}
246
247	ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
248				DA9052_ALARM_Y_TICK_ON, 0);
249	if (ret != 0)
250		rtc_err(rtc, "Failed to disable TICKS: %d\n", ret);
251
252	ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM",
253				da9052_rtc_irq, rtc);
254	if (ret != 0) {
255		rtc_err(rtc, "irq registration failed: %d\n", ret);
256		return ret;
257	}
258
259	rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
260				       &da9052_rtc_ops, THIS_MODULE);
261	return PTR_ERR_OR_ZERO(rtc->rtc);
262}
263
264static struct platform_driver da9052_rtc_driver = {
265	.probe	= da9052_rtc_probe,
266	.driver = {
267		.name	= "da9052-rtc",
268		.owner	= THIS_MODULE,
269	},
270};
271
272module_platform_driver(da9052_rtc_driver);
273
274MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
275MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC");
276MODULE_LICENSE("GPL");
277MODULE_ALIAS("platform:da9052-rtc");
278