xref: /openbmc/linux/drivers/rtc/rtc-da9052.c (revision f677b30b487ca3763c3de3f1b4d8c976c2961cd1)
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(da9052, fmt, ...) \
24 		dev_err(da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__)
25 
26 struct da9052_rtc {
27 	struct rtc_device *rtc;
28 	struct da9052 *da9052;
29 	int irq;
30 };
31 
32 static int da9052_rtc_enable_alarm(struct da9052 *da9052, bool enable)
33 {
34 	int ret;
35 	if (enable) {
36 		ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
37 					DA9052_ALARM_Y_ALARM_ON,
38 					DA9052_ALARM_Y_ALARM_ON);
39 		if (ret != 0)
40 			rtc_err(da9052, "Failed to enable ALM: %d\n", ret);
41 	} else {
42 		ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
43 					DA9052_ALARM_Y_ALARM_ON, 0);
44 		if (ret != 0)
45 			rtc_err(da9052, "Write error: %d\n", ret);
46 	}
47 	return ret;
48 }
49 
50 static irqreturn_t da9052_rtc_irq(int irq, void *data)
51 {
52 	struct da9052_rtc *rtc = data;
53 	int ret;
54 
55 	ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_MI_REG);
56 	if (ret < 0) {
57 		rtc_err(rtc->da9052, "Read error: %d\n", ret);
58 		return IRQ_NONE;
59 	}
60 
61 	if (ret & DA9052_ALARMMI_ALARMTYPE) {
62 		da9052_rtc_enable_alarm(rtc->da9052, 0);
63 		rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
64 	} else
65 		rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_PF);
66 
67 	return IRQ_HANDLED;
68 }
69 
70 static int da9052_read_alarm(struct da9052 *da9052, struct rtc_time *rtc_tm)
71 {
72 	int ret;
73 	uint8_t v[5];
74 
75 	ret = da9052_group_read(da9052, DA9052_ALARM_MI_REG, 5, v);
76 	if (ret != 0) {
77 		rtc_err(da9052, "Failed to group read ALM: %d\n", ret);
78 		return ret;
79 	}
80 
81 	rtc_tm->tm_year = (v[4] & DA9052_RTC_YEAR) + 100;
82 	rtc_tm->tm_mon  = (v[3] & DA9052_RTC_MONTH) - 1;
83 	rtc_tm->tm_mday = v[2] & DA9052_RTC_DAY;
84 	rtc_tm->tm_hour = v[1] & DA9052_RTC_HOUR;
85 	rtc_tm->tm_min  = v[0] & DA9052_RTC_MIN;
86 
87 	ret = rtc_valid_tm(rtc_tm);
88 	if (ret != 0)
89 		return ret;
90 	return ret;
91 }
92 
93 static int da9052_set_alarm(struct da9052 *da9052, struct rtc_time *rtc_tm)
94 {
95 	int ret;
96 	uint8_t v[3];
97 
98 	rtc_tm->tm_year -= 100;
99 	rtc_tm->tm_mon += 1;
100 
101 	ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG,
102 				DA9052_RTC_MIN, rtc_tm->tm_min);
103 	if (ret != 0) {
104 		rtc_err(da9052, "Failed to write ALRM MIN: %d\n", ret);
105 		return ret;
106 	}
107 
108 	v[0] = rtc_tm->tm_hour;
109 	v[1] = rtc_tm->tm_mday;
110 	v[2] = rtc_tm->tm_mon;
111 
112 	ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v);
113 	if (ret < 0)
114 		return ret;
115 
116 	ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
117 				DA9052_RTC_YEAR, rtc_tm->tm_year);
118 	if (ret != 0)
119 		rtc_err(da9052, "Failed to write ALRM YEAR: %d\n", ret);
120 
121 	return ret;
122 }
123 
124 static int da9052_rtc_get_alarm_status(struct da9052 *da9052)
125 {
126 	int ret;
127 
128 	ret = da9052_reg_read(da9052, DA9052_ALARM_Y_REG);
129 	if (ret < 0) {
130 		rtc_err(da9052, "Failed to read ALM: %d\n", ret);
131 		return ret;
132 	}
133 	ret &= DA9052_ALARM_Y_ALARM_ON;
134 	return (ret > 0) ? 1 : 0;
135 }
136 
137 static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
138 {
139 	struct da9052_rtc *rtc = dev_get_drvdata(dev);
140 	uint8_t v[6];
141 	int ret;
142 
143 	ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
144 	if (ret < 0) {
145 		rtc_err(rtc->da9052, "Failed to read RTC time : %d\n", ret);
146 		return ret;
147 	}
148 
149 	rtc_tm->tm_year = (v[5] & DA9052_RTC_YEAR) + 100;
150 	rtc_tm->tm_mon  = (v[4] & DA9052_RTC_MONTH) - 1;
151 	rtc_tm->tm_mday = v[3] & DA9052_RTC_DAY;
152 	rtc_tm->tm_hour = v[2] & DA9052_RTC_HOUR;
153 	rtc_tm->tm_min  = v[1] & DA9052_RTC_MIN;
154 	rtc_tm->tm_sec  = v[0] & DA9052_RTC_SEC;
155 
156 	ret = rtc_valid_tm(rtc_tm);
157 	if (ret != 0) {
158 		rtc_err(rtc->da9052, "rtc_valid_tm failed: %d\n", ret);
159 		return ret;
160 	}
161 
162 	return 0;
163 }
164 
165 static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm)
166 {
167 	struct da9052_rtc *rtc;
168 	uint8_t v[6];
169 
170 	rtc = dev_get_drvdata(dev);
171 
172 	v[0] = tm->tm_sec;
173 	v[1] = tm->tm_min;
174 	v[2] = tm->tm_hour;
175 	v[3] = tm->tm_mday;
176 	v[4] = tm->tm_mon + 1;
177 	v[5] = tm->tm_year - 100;
178 
179 	return da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
180 }
181 
182 static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
183 {
184 	int ret;
185 	struct rtc_time *tm = &alrm->time;
186 	struct da9052_rtc *rtc = dev_get_drvdata(dev);
187 
188 	ret = da9052_read_alarm(rtc->da9052, tm);
189 
190 	if (ret)
191 		return ret;
192 
193 	alrm->enabled = da9052_rtc_get_alarm_status(rtc->da9052);
194 
195 	return 0;
196 }
197 
198 static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
199 {
200 	int ret;
201 	struct rtc_time *tm = &alrm->time;
202 	struct da9052_rtc *rtc = dev_get_drvdata(dev);
203 
204 	ret = da9052_rtc_enable_alarm(rtc->da9052, 0);
205 	if (ret < 0)
206 		return ret;
207 
208 	ret = da9052_set_alarm(rtc->da9052, tm);
209 	if (ret)
210 		return ret;
211 
212 	ret = da9052_rtc_enable_alarm(rtc->da9052, 1);
213 
214 	return ret;
215 }
216 
217 static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
218 {
219 	struct da9052_rtc *rtc = dev_get_drvdata(dev);
220 
221 	return da9052_rtc_enable_alarm(rtc->da9052, enabled);
222 }
223 
224 static const struct rtc_class_ops da9052_rtc_ops = {
225 	.read_time	= da9052_rtc_read_time,
226 	.set_time	= da9052_rtc_set_time,
227 	.read_alarm	= da9052_rtc_read_alarm,
228 	.set_alarm	= da9052_rtc_set_alarm,
229 	.alarm_irq_enable = da9052_rtc_alarm_irq_enable,
230 };
231 
232 static int da9052_rtc_probe(struct platform_device *pdev)
233 {
234 	struct da9052_rtc *rtc;
235 	int ret;
236 
237 	rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL);
238 	if (!rtc)
239 		return -ENOMEM;
240 
241 	rtc->da9052 = dev_get_drvdata(pdev->dev.parent);
242 	platform_set_drvdata(pdev, rtc);
243 	rtc->irq =  DA9052_IRQ_ALARM;
244 	ret = da9052_request_irq(rtc->da9052, rtc->irq, "ALM",
245 				da9052_rtc_irq, rtc);
246 	if (ret != 0) {
247 		rtc_err(rtc->da9052, "irq registration failed: %d\n", ret);
248 		return ret;
249 	}
250 
251 	rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
252 				       &da9052_rtc_ops, THIS_MODULE);
253 	return PTR_ERR_OR_ZERO(rtc->rtc);
254 }
255 
256 static struct platform_driver da9052_rtc_driver = {
257 	.probe	= da9052_rtc_probe,
258 	.driver = {
259 		.name	= "da9052-rtc",
260 		.owner	= THIS_MODULE,
261 	},
262 };
263 
264 module_platform_driver(da9052_rtc_driver);
265 
266 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
267 MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC");
268 MODULE_LICENSE("GPL");
269 MODULE_ALIAS("platform:da9052-rtc");
270