1 /* NXP PCF50633 RTC Driver
2  *
3  * (C) 2006-2008 by Openmoko, Inc.
4  * Author: Balaji Rao <balajirrao@openmoko.org>
5  * All rights reserved.
6  *
7  * Broken down from monstrous PCF50633 driver mainly by
8  * Harald Welte, Andy Green and Werner Almesberger
9  *
10  *  This program is free software; you can redistribute  it and/or modify it
11  *  under  the terms of  the GNU General  Public License as published by the
12  *  Free Software Foundation;  either version 2 of the  License, or (at your
13  *  option) any later version.
14  *
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/device.h>
21 #include <linux/slab.h>
22 #include <linux/platform_device.h>
23 #include <linux/rtc.h>
24 #include <linux/bcd.h>
25 #include <linux/err.h>
26 
27 #include <linux/mfd/pcf50633/core.h>
28 
29 #define PCF50633_REG_RTCSC	0x59 /* Second */
30 #define PCF50633_REG_RTCMN	0x5a /* Minute */
31 #define PCF50633_REG_RTCHR	0x5b /* Hour */
32 #define PCF50633_REG_RTCWD	0x5c /* Weekday */
33 #define PCF50633_REG_RTCDT	0x5d /* Day */
34 #define PCF50633_REG_RTCMT	0x5e /* Month */
35 #define PCF50633_REG_RTCYR	0x5f /* Year */
36 #define PCF50633_REG_RTCSCA	0x60 /* Alarm Second */
37 #define PCF50633_REG_RTCMNA	0x61 /* Alarm Minute */
38 #define PCF50633_REG_RTCHRA	0x62 /* Alarm Hour */
39 #define PCF50633_REG_RTCWDA	0x63 /* Alarm Weekday */
40 #define PCF50633_REG_RTCDTA	0x64 /* Alarm Day */
41 #define PCF50633_REG_RTCMTA	0x65 /* Alarm Month */
42 #define PCF50633_REG_RTCYRA	0x66 /* Alarm Year */
43 
44 enum pcf50633_time_indexes {
45 	PCF50633_TI_SEC,
46 	PCF50633_TI_MIN,
47 	PCF50633_TI_HOUR,
48 	PCF50633_TI_WKDAY,
49 	PCF50633_TI_DAY,
50 	PCF50633_TI_MONTH,
51 	PCF50633_TI_YEAR,
52 	PCF50633_TI_EXTENT /* always last */
53 };
54 
55 struct pcf50633_time {
56 	u_int8_t time[PCF50633_TI_EXTENT];
57 };
58 
59 struct pcf50633_rtc {
60 	int alarm_enabled;
61 	int alarm_pending;
62 
63 	struct pcf50633 *pcf;
64 	struct rtc_device *rtc_dev;
65 };
66 
pcf2rtc_time(struct rtc_time * rtc,struct pcf50633_time * pcf)67 static void pcf2rtc_time(struct rtc_time *rtc, struct pcf50633_time *pcf)
68 {
69 	rtc->tm_sec = bcd2bin(pcf->time[PCF50633_TI_SEC]);
70 	rtc->tm_min = bcd2bin(pcf->time[PCF50633_TI_MIN]);
71 	rtc->tm_hour = bcd2bin(pcf->time[PCF50633_TI_HOUR]);
72 	rtc->tm_wday = bcd2bin(pcf->time[PCF50633_TI_WKDAY]);
73 	rtc->tm_mday = bcd2bin(pcf->time[PCF50633_TI_DAY]);
74 	rtc->tm_mon = bcd2bin(pcf->time[PCF50633_TI_MONTH]) - 1;
75 	rtc->tm_year = bcd2bin(pcf->time[PCF50633_TI_YEAR]) + 100;
76 }
77 
rtc2pcf_time(struct pcf50633_time * pcf,struct rtc_time * rtc)78 static void rtc2pcf_time(struct pcf50633_time *pcf, struct rtc_time *rtc)
79 {
80 	pcf->time[PCF50633_TI_SEC] = bin2bcd(rtc->tm_sec);
81 	pcf->time[PCF50633_TI_MIN] = bin2bcd(rtc->tm_min);
82 	pcf->time[PCF50633_TI_HOUR] = bin2bcd(rtc->tm_hour);
83 	pcf->time[PCF50633_TI_WKDAY] = bin2bcd(rtc->tm_wday);
84 	pcf->time[PCF50633_TI_DAY] = bin2bcd(rtc->tm_mday);
85 	pcf->time[PCF50633_TI_MONTH] = bin2bcd(rtc->tm_mon + 1);
86 	pcf->time[PCF50633_TI_YEAR] = bin2bcd(rtc->tm_year % 100);
87 }
88 
89 static int
pcf50633_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)90 pcf50633_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
91 {
92 	struct pcf50633_rtc *rtc = dev_get_drvdata(dev);
93 	int err;
94 
95 	if (enabled)
96 		err = pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
97 	else
98 		err = pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
99 
100 	if (err < 0)
101 		return err;
102 
103 	rtc->alarm_enabled = enabled;
104 
105 	return 0;
106 }
107 
pcf50633_rtc_read_time(struct device * dev,struct rtc_time * tm)108 static int pcf50633_rtc_read_time(struct device *dev, struct rtc_time *tm)
109 {
110 	struct pcf50633_rtc *rtc;
111 	struct pcf50633_time pcf_tm;
112 	int ret;
113 
114 	rtc = dev_get_drvdata(dev);
115 
116 	ret = pcf50633_read_block(rtc->pcf, PCF50633_REG_RTCSC,
117 					    PCF50633_TI_EXTENT,
118 					    &pcf_tm.time[0]);
119 	if (ret != PCF50633_TI_EXTENT) {
120 		dev_err(dev, "Failed to read time\n");
121 		return -EIO;
122 	}
123 
124 	dev_dbg(dev, "PCF_TIME: %02x.%02x.%02x %02x:%02x:%02x\n",
125 		pcf_tm.time[PCF50633_TI_DAY],
126 		pcf_tm.time[PCF50633_TI_MONTH],
127 		pcf_tm.time[PCF50633_TI_YEAR],
128 		pcf_tm.time[PCF50633_TI_HOUR],
129 		pcf_tm.time[PCF50633_TI_MIN],
130 		pcf_tm.time[PCF50633_TI_SEC]);
131 
132 	pcf2rtc_time(tm, &pcf_tm);
133 
134 	dev_dbg(dev, "RTC_TIME: %u.%u.%u %u:%u:%u\n",
135 		tm->tm_mday, tm->tm_mon, tm->tm_year,
136 		tm->tm_hour, tm->tm_min, tm->tm_sec);
137 
138 	return 0;
139 }
140 
pcf50633_rtc_set_time(struct device * dev,struct rtc_time * tm)141 static int pcf50633_rtc_set_time(struct device *dev, struct rtc_time *tm)
142 {
143 	struct pcf50633_rtc *rtc;
144 	struct pcf50633_time pcf_tm;
145 	int alarm_masked, ret = 0;
146 
147 	rtc = dev_get_drvdata(dev);
148 
149 	dev_dbg(dev, "RTC_TIME: %u.%u.%u %u:%u:%u\n",
150 		tm->tm_mday, tm->tm_mon, tm->tm_year,
151 		tm->tm_hour, tm->tm_min, tm->tm_sec);
152 
153 	rtc2pcf_time(&pcf_tm, tm);
154 
155 	dev_dbg(dev, "PCF_TIME: %02x.%02x.%02x %02x:%02x:%02x\n",
156 		pcf_tm.time[PCF50633_TI_DAY],
157 		pcf_tm.time[PCF50633_TI_MONTH],
158 		pcf_tm.time[PCF50633_TI_YEAR],
159 		pcf_tm.time[PCF50633_TI_HOUR],
160 		pcf_tm.time[PCF50633_TI_MIN],
161 		pcf_tm.time[PCF50633_TI_SEC]);
162 
163 
164 	alarm_masked = pcf50633_irq_mask_get(rtc->pcf, PCF50633_IRQ_ALARM);
165 
166 	if (!alarm_masked)
167 		pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
168 
169 	/* Returns 0 on success */
170 	ret = pcf50633_write_block(rtc->pcf, PCF50633_REG_RTCSC,
171 					     PCF50633_TI_EXTENT,
172 					     &pcf_tm.time[0]);
173 
174 	if (!alarm_masked)
175 		pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
176 
177 	return ret;
178 }
179 
pcf50633_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alrm)180 static int pcf50633_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
181 {
182 	struct pcf50633_rtc *rtc;
183 	struct pcf50633_time pcf_tm;
184 	int ret = 0;
185 
186 	rtc = dev_get_drvdata(dev);
187 
188 	alrm->enabled = rtc->alarm_enabled;
189 	alrm->pending = rtc->alarm_pending;
190 
191 	ret = pcf50633_read_block(rtc->pcf, PCF50633_REG_RTCSCA,
192 				PCF50633_TI_EXTENT, &pcf_tm.time[0]);
193 	if (ret != PCF50633_TI_EXTENT) {
194 		dev_err(dev, "Failed to read time\n");
195 		return -EIO;
196 	}
197 
198 	pcf2rtc_time(&alrm->time, &pcf_tm);
199 
200 	return rtc_valid_tm(&alrm->time);
201 }
202 
pcf50633_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)203 static int pcf50633_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
204 {
205 	struct pcf50633_rtc *rtc;
206 	struct pcf50633_time pcf_tm;
207 	int alarm_masked, ret = 0;
208 
209 	rtc = dev_get_drvdata(dev);
210 
211 	rtc2pcf_time(&pcf_tm, &alrm->time);
212 
213 	/* do like mktime does and ignore tm_wday */
214 	pcf_tm.time[PCF50633_TI_WKDAY] = 7;
215 
216 	alarm_masked = pcf50633_irq_mask_get(rtc->pcf, PCF50633_IRQ_ALARM);
217 
218 	/* disable alarm interrupt */
219 	if (!alarm_masked)
220 		pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
221 
222 	/* Returns 0 on success */
223 	ret = pcf50633_write_block(rtc->pcf, PCF50633_REG_RTCSCA,
224 				PCF50633_TI_EXTENT, &pcf_tm.time[0]);
225 	if (!alrm->enabled)
226 		rtc->alarm_pending = 0;
227 
228 	if (!alarm_masked || alrm->enabled)
229 		pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
230 	rtc->alarm_enabled = alrm->enabled;
231 
232 	return ret;
233 }
234 
235 static const struct rtc_class_ops pcf50633_rtc_ops = {
236 	.read_time		= pcf50633_rtc_read_time,
237 	.set_time		= pcf50633_rtc_set_time,
238 	.read_alarm		= pcf50633_rtc_read_alarm,
239 	.set_alarm		= pcf50633_rtc_set_alarm,
240 	.alarm_irq_enable	= pcf50633_rtc_alarm_irq_enable,
241 };
242 
pcf50633_rtc_irq(int irq,void * data)243 static void pcf50633_rtc_irq(int irq, void *data)
244 {
245 	struct pcf50633_rtc *rtc = data;
246 
247 	rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
248 	rtc->alarm_pending = 1;
249 }
250 
pcf50633_rtc_probe(struct platform_device * pdev)251 static int pcf50633_rtc_probe(struct platform_device *pdev)
252 {
253 	struct pcf50633_rtc *rtc;
254 
255 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
256 	if (!rtc)
257 		return -ENOMEM;
258 
259 	rtc->pcf = dev_to_pcf50633(pdev->dev.parent);
260 	platform_set_drvdata(pdev, rtc);
261 	rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "pcf50633-rtc",
262 				&pcf50633_rtc_ops, THIS_MODULE);
263 
264 	if (IS_ERR(rtc->rtc_dev))
265 		return PTR_ERR(rtc->rtc_dev);
266 
267 	pcf50633_register_irq(rtc->pcf, PCF50633_IRQ_ALARM,
268 					pcf50633_rtc_irq, rtc);
269 	return 0;
270 }
271 
pcf50633_rtc_remove(struct platform_device * pdev)272 static int pcf50633_rtc_remove(struct platform_device *pdev)
273 {
274 	struct pcf50633_rtc *rtc;
275 
276 	rtc = platform_get_drvdata(pdev);
277 	pcf50633_free_irq(rtc->pcf, PCF50633_IRQ_ALARM);
278 
279 	return 0;
280 }
281 
282 static struct platform_driver pcf50633_rtc_driver = {
283 	.driver = {
284 		.name = "pcf50633-rtc",
285 	},
286 	.probe = pcf50633_rtc_probe,
287 	.remove = pcf50633_rtc_remove,
288 };
289 
290 module_platform_driver(pcf50633_rtc_driver);
291 
292 MODULE_DESCRIPTION("PCF50633 RTC driver");
293 MODULE_AUTHOR("Balaji Rao <balajirrao@openmoko.org>");
294 MODULE_LICENSE("GPL");
295 
296