drivers/rtc/rtc-max8998.c: check for pdata presence before dereferencing
[linux-2.6.git] / drivers / rtc / rtc-pcf50633.c
blobe6b6911c8e0528b326e6a0e93050510f81735b52
1 /* NXP PCF50633 RTC Driver
3 * (C) 2006-2008 by Openmoko, Inc.
4 * Author: Balaji Rao <balajirrao@openmoko.org>
5 * All rights reserved.
7 * Broken down from monstrous PCF50633 driver mainly by
8 * Harald Welte, Andy Green and Werner Almesberger
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.
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>
27 #include <linux/mfd/pcf50633/core.h>
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 */
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 */
55 struct pcf50633_time {
56 u_int8_t time[PCF50633_TI_EXTENT];
59 struct pcf50633_rtc {
60 int alarm_enabled;
61 int alarm_pending;
63 struct pcf50633 *pcf;
64 struct rtc_device *rtc_dev;
67 static void pcf2rtc_time(struct rtc_time *rtc, struct pcf50633_time *pcf)
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;
78 static void rtc2pcf_time(struct pcf50633_time *pcf, struct rtc_time *rtc)
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);
89 static int
90 pcf50633_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
92 struct pcf50633_rtc *rtc = dev_get_drvdata(dev);
93 int err;
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);
100 if (err < 0)
101 return err;
103 rtc->alarm_enabled = enabled;
105 return 0;
108 static int pcf50633_rtc_read_time(struct device *dev, struct rtc_time *tm)
110 struct pcf50633_rtc *rtc;
111 struct pcf50633_time pcf_tm;
112 int ret;
114 rtc = dev_get_drvdata(dev);
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;
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]);
132 pcf2rtc_time(tm, &pcf_tm);
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);
138 return rtc_valid_tm(tm);
141 static int pcf50633_rtc_set_time(struct device *dev, struct rtc_time *tm)
143 struct pcf50633_rtc *rtc;
144 struct pcf50633_time pcf_tm;
145 int alarm_masked, ret = 0;
147 rtc = dev_get_drvdata(dev);
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);
153 rtc2pcf_time(&pcf_tm, tm);
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]);
164 alarm_masked = pcf50633_irq_mask_get(rtc->pcf, PCF50633_IRQ_ALARM);
166 if (!alarm_masked)
167 pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
169 /* Returns 0 on success */
170 ret = pcf50633_write_block(rtc->pcf, PCF50633_REG_RTCSC,
171 PCF50633_TI_EXTENT,
172 &pcf_tm.time[0]);
174 if (!alarm_masked)
175 pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
177 return ret;
180 static int pcf50633_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
182 struct pcf50633_rtc *rtc;
183 struct pcf50633_time pcf_tm;
184 int ret = 0;
186 rtc = dev_get_drvdata(dev);
188 alrm->enabled = rtc->alarm_enabled;
189 alrm->pending = rtc->alarm_pending;
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;
198 pcf2rtc_time(&alrm->time, &pcf_tm);
200 return rtc_valid_tm(&alrm->time);
203 static int pcf50633_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
205 struct pcf50633_rtc *rtc;
206 struct pcf50633_time pcf_tm;
207 int alarm_masked, ret = 0;
209 rtc = dev_get_drvdata(dev);
211 rtc2pcf_time(&pcf_tm, &alrm->time);
213 /* do like mktime does and ignore tm_wday */
214 pcf_tm.time[PCF50633_TI_WKDAY] = 7;
216 alarm_masked = pcf50633_irq_mask_get(rtc->pcf, PCF50633_IRQ_ALARM);
218 /* disable alarm interrupt */
219 if (!alarm_masked)
220 pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
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;
228 if (!alarm_masked || alrm->enabled)
229 pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
230 rtc->alarm_enabled = alrm->enabled;
232 return ret;
235 static 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,
243 static void pcf50633_rtc_irq(int irq, void *data)
245 struct pcf50633_rtc *rtc = data;
247 rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
248 rtc->alarm_pending = 1;
251 static int pcf50633_rtc_probe(struct platform_device *pdev)
253 struct pcf50633_rtc *rtc;
255 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
256 if (!rtc)
257 return -ENOMEM;
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);
264 if (IS_ERR(rtc->rtc_dev))
265 return PTR_ERR(rtc->rtc_dev);
267 pcf50633_register_irq(rtc->pcf, PCF50633_IRQ_ALARM,
268 pcf50633_rtc_irq, rtc);
269 return 0;
272 static int pcf50633_rtc_remove(struct platform_device *pdev)
274 struct pcf50633_rtc *rtc;
276 rtc = platform_get_drvdata(pdev);
277 pcf50633_free_irq(rtc->pcf, PCF50633_IRQ_ALARM);
279 return 0;
282 static struct platform_driver pcf50633_rtc_driver = {
283 .driver = {
284 .name = "pcf50633-rtc",
286 .probe = pcf50633_rtc_probe,
287 .remove = pcf50633_rtc_remove,
290 module_platform_driver(pcf50633_rtc_driver);
292 MODULE_DESCRIPTION("PCF50633 RTC driver");
293 MODULE_AUTHOR("Balaji Rao <balajirrao@openmoko.org>");
294 MODULE_LICENSE("GPL");