1// SPDX-License-Identifier: GPL-2.0-or-later
2/* NXP PCF50633 RTC Driver
3 *
4 * (C) 2006-2008 by Openmoko, Inc.
5 * Author: Balaji Rao <balajirrao@openmoko.org>
6 * All rights reserved.
7 *
8 * Broken down from monstrous PCF50633 driver mainly by
9 * Harald Welte, Andy Green and Werner Almesberger
10 */
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/device.h>
16#include <linux/slab.h>
17#include <linux/platform_device.h>
18#include <linux/rtc.h>
19#include <linux/bcd.h>
20#include <linux/err.h>
21
22#include <linux/mfd/pcf50633/core.h>
23
24#define PCF50633_REG_RTCSC	0x59 /* Second */
25#define PCF50633_REG_RTCMN	0x5a /* Minute */
26#define PCF50633_REG_RTCHR	0x5b /* Hour */
27#define PCF50633_REG_RTCWD	0x5c /* Weekday */
28#define PCF50633_REG_RTCDT	0x5d /* Day */
29#define PCF50633_REG_RTCMT	0x5e /* Month */
30#define PCF50633_REG_RTCYR	0x5f /* Year */
31#define PCF50633_REG_RTCSCA	0x60 /* Alarm Second */
32#define PCF50633_REG_RTCMNA	0x61 /* Alarm Minute */
33#define PCF50633_REG_RTCHRA	0x62 /* Alarm Hour */
34#define PCF50633_REG_RTCWDA	0x63 /* Alarm Weekday */
35#define PCF50633_REG_RTCDTA	0x64 /* Alarm Day */
36#define PCF50633_REG_RTCMTA	0x65 /* Alarm Month */
37#define PCF50633_REG_RTCYRA	0x66 /* Alarm Year */
38
39enum pcf50633_time_indexes {
40	PCF50633_TI_SEC,
41	PCF50633_TI_MIN,
42	PCF50633_TI_HOUR,
43	PCF50633_TI_WKDAY,
44	PCF50633_TI_DAY,
45	PCF50633_TI_MONTH,
46	PCF50633_TI_YEAR,
47	PCF50633_TI_EXTENT /* always last */
48};
49
50struct pcf50633_time {
51	u_int8_t time[PCF50633_TI_EXTENT];
52};
53
54struct pcf50633_rtc {
55	int alarm_enabled;
56	int alarm_pending;
57
58	struct pcf50633 *pcf;
59	struct rtc_device *rtc_dev;
60};
61
62static void pcf2rtc_time(struct rtc_time *rtc, struct pcf50633_time *pcf)
63{
64	rtc->tm_sec = bcd2bin(pcf->time[PCF50633_TI_SEC]);
65	rtc->tm_min = bcd2bin(pcf->time[PCF50633_TI_MIN]);
66	rtc->tm_hour = bcd2bin(pcf->time[PCF50633_TI_HOUR]);
67	rtc->tm_wday = bcd2bin(pcf->time[PCF50633_TI_WKDAY]);
68	rtc->tm_mday = bcd2bin(pcf->time[PCF50633_TI_DAY]);
69	rtc->tm_mon = bcd2bin(pcf->time[PCF50633_TI_MONTH]) - 1;
70	rtc->tm_year = bcd2bin(pcf->time[PCF50633_TI_YEAR]) + 100;
71}
72
73static void rtc2pcf_time(struct pcf50633_time *pcf, struct rtc_time *rtc)
74{
75	pcf->time[PCF50633_TI_SEC] = bin2bcd(rtc->tm_sec);
76	pcf->time[PCF50633_TI_MIN] = bin2bcd(rtc->tm_min);
77	pcf->time[PCF50633_TI_HOUR] = bin2bcd(rtc->tm_hour);
78	pcf->time[PCF50633_TI_WKDAY] = bin2bcd(rtc->tm_wday);
79	pcf->time[PCF50633_TI_DAY] = bin2bcd(rtc->tm_mday);
80	pcf->time[PCF50633_TI_MONTH] = bin2bcd(rtc->tm_mon + 1);
81	pcf->time[PCF50633_TI_YEAR] = bin2bcd(rtc->tm_year % 100);
82}
83
84static int
85pcf50633_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
86{
87	struct pcf50633_rtc *rtc = dev_get_drvdata(dev);
88	int err;
89
90	if (enabled)
91		err = pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
92	else
93		err = pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
94
95	if (err < 0)
96		return err;
97
98	rtc->alarm_enabled = enabled;
99
100	return 0;
101}
102
103static int pcf50633_rtc_read_time(struct device *dev, struct rtc_time *tm)
104{
105	struct pcf50633_rtc *rtc;
106	struct pcf50633_time pcf_tm;
107	int ret;
108
109	rtc = dev_get_drvdata(dev);
110
111	ret = pcf50633_read_block(rtc->pcf, PCF50633_REG_RTCSC,
112					    PCF50633_TI_EXTENT,
113					    &pcf_tm.time[0]);
114	if (ret != PCF50633_TI_EXTENT) {
115		dev_err(dev, "Failed to read time\n");
116		return -EIO;
117	}
118
119	dev_dbg(dev, "PCF_TIME: %02x.%02x.%02x %02x:%02x:%02x\n",
120		pcf_tm.time[PCF50633_TI_DAY],
121		pcf_tm.time[PCF50633_TI_MONTH],
122		pcf_tm.time[PCF50633_TI_YEAR],
123		pcf_tm.time[PCF50633_TI_HOUR],
124		pcf_tm.time[PCF50633_TI_MIN],
125		pcf_tm.time[PCF50633_TI_SEC]);
126
127	pcf2rtc_time(tm, &pcf_tm);
128
129	dev_dbg(dev, "RTC_TIME: %ptRr\n", tm);
130
131	return 0;
132}
133
134static int pcf50633_rtc_set_time(struct device *dev, struct rtc_time *tm)
135{
136	struct pcf50633_rtc *rtc;
137	struct pcf50633_time pcf_tm;
138	int alarm_masked, ret = 0;
139
140	rtc = dev_get_drvdata(dev);
141
142	dev_dbg(dev, "RTC_TIME: %ptRr\n", tm);
143
144	rtc2pcf_time(&pcf_tm, tm);
145
146	dev_dbg(dev, "PCF_TIME: %02x.%02x.%02x %02x:%02x:%02x\n",
147		pcf_tm.time[PCF50633_TI_DAY],
148		pcf_tm.time[PCF50633_TI_MONTH],
149		pcf_tm.time[PCF50633_TI_YEAR],
150		pcf_tm.time[PCF50633_TI_HOUR],
151		pcf_tm.time[PCF50633_TI_MIN],
152		pcf_tm.time[PCF50633_TI_SEC]);
153
154
155	alarm_masked = pcf50633_irq_mask_get(rtc->pcf, PCF50633_IRQ_ALARM);
156
157	if (!alarm_masked)
158		pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
159
160	/* Returns 0 on success */
161	ret = pcf50633_write_block(rtc->pcf, PCF50633_REG_RTCSC,
162					     PCF50633_TI_EXTENT,
163					     &pcf_tm.time[0]);
164
165	if (!alarm_masked)
166		pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
167
168	return ret;
169}
170
171static int pcf50633_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
172{
173	struct pcf50633_rtc *rtc;
174	struct pcf50633_time pcf_tm;
175	int ret = 0;
176
177	rtc = dev_get_drvdata(dev);
178
179	alrm->enabled = rtc->alarm_enabled;
180	alrm->pending = rtc->alarm_pending;
181
182	ret = pcf50633_read_block(rtc->pcf, PCF50633_REG_RTCSCA,
183				PCF50633_TI_EXTENT, &pcf_tm.time[0]);
184	if (ret != PCF50633_TI_EXTENT) {
185		dev_err(dev, "Failed to read time\n");
186		return -EIO;
187	}
188
189	pcf2rtc_time(&alrm->time, &pcf_tm);
190
191	return rtc_valid_tm(&alrm->time);
192}
193
194static int pcf50633_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
195{
196	struct pcf50633_rtc *rtc;
197	struct pcf50633_time pcf_tm;
198	int alarm_masked, ret = 0;
199
200	rtc = dev_get_drvdata(dev);
201
202	rtc2pcf_time(&pcf_tm, &alrm->time);
203
204	/* do like mktime does and ignore tm_wday */
205	pcf_tm.time[PCF50633_TI_WKDAY] = 7;
206
207	alarm_masked = pcf50633_irq_mask_get(rtc->pcf, PCF50633_IRQ_ALARM);
208
209	/* disable alarm interrupt */
210	if (!alarm_masked)
211		pcf50633_irq_mask(rtc->pcf, PCF50633_IRQ_ALARM);
212
213	/* Returns 0 on success */
214	ret = pcf50633_write_block(rtc->pcf, PCF50633_REG_RTCSCA,
215				PCF50633_TI_EXTENT, &pcf_tm.time[0]);
216	if (!alrm->enabled)
217		rtc->alarm_pending = 0;
218
219	if (!alarm_masked || alrm->enabled)
220		pcf50633_irq_unmask(rtc->pcf, PCF50633_IRQ_ALARM);
221	rtc->alarm_enabled = alrm->enabled;
222
223	return ret;
224}
225
226static const struct rtc_class_ops pcf50633_rtc_ops = {
227	.read_time		= pcf50633_rtc_read_time,
228	.set_time		= pcf50633_rtc_set_time,
229	.read_alarm		= pcf50633_rtc_read_alarm,
230	.set_alarm		= pcf50633_rtc_set_alarm,
231	.alarm_irq_enable	= pcf50633_rtc_alarm_irq_enable,
232};
233
234static void pcf50633_rtc_irq(int irq, void *data)
235{
236	struct pcf50633_rtc *rtc = data;
237
238	rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
239	rtc->alarm_pending = 1;
240}
241
242static int pcf50633_rtc_probe(struct platform_device *pdev)
243{
244	struct pcf50633_rtc *rtc;
245
246	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
247	if (!rtc)
248		return -ENOMEM;
249
250	rtc->pcf = dev_to_pcf50633(pdev->dev.parent);
251	platform_set_drvdata(pdev, rtc);
252	rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "pcf50633-rtc",
253				&pcf50633_rtc_ops, THIS_MODULE);
254
255	if (IS_ERR(rtc->rtc_dev))
256		return PTR_ERR(rtc->rtc_dev);
257
258	pcf50633_register_irq(rtc->pcf, PCF50633_IRQ_ALARM,
259					pcf50633_rtc_irq, rtc);
260	return 0;
261}
262
263static void pcf50633_rtc_remove(struct platform_device *pdev)
264{
265	struct pcf50633_rtc *rtc;
266
267	rtc = platform_get_drvdata(pdev);
268	pcf50633_free_irq(rtc->pcf, PCF50633_IRQ_ALARM);
269}
270
271static struct platform_driver pcf50633_rtc_driver = {
272	.driver = {
273		.name = "pcf50633-rtc",
274	},
275	.probe = pcf50633_rtc_probe,
276	.remove_new = pcf50633_rtc_remove,
277};
278
279module_platform_driver(pcf50633_rtc_driver);
280
281MODULE_DESCRIPTION("PCF50633 RTC driver");
282MODULE_AUTHOR("Balaji Rao <balajirrao@openmoko.org>");
283MODULE_LICENSE("GPL");
284
285