blob: e094ffa434f827eb3cce26aa470f3a5a9f11c300 [file] [log] [blame]
Stephen Warren94c01ab2012-10-04 17:13:56 -07001/*
2 * RTC driver for Maxim MAX8907
3 *
4 * Copyright (c) 2011-2012, NVIDIA Corporation.
5 *
6 * Based on drivers/rtc/rtc-max8925.c,
7 * Copyright (C) 2009-2010 Marvell International Ltd.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#include <linux/bcd.h>
15#include <linux/i2c.h>
16#include <linux/mfd/max8907.h>
17#include <linux/module.h>
18#include <linux/platform_device.h>
19#include <linux/regmap.h>
20#include <linux/rtc.h>
21#include <linux/slab.h>
22
23enum {
24 RTC_SEC = 0,
25 RTC_MIN,
26 RTC_HOUR,
27 RTC_WEEKDAY,
28 RTC_DATE,
29 RTC_MONTH,
30 RTC_YEAR1,
31 RTC_YEAR2,
32};
33
34#define TIME_NUM 8
35#define ALARM_1SEC (1 << 7)
36#define HOUR_12 (1 << 7)
37#define HOUR_AM_PM (1 << 5)
38#define ALARM0_IRQ (1 << 3)
39#define ALARM1_IRQ (1 << 2)
40#define ALARM0_STATUS (1 << 2)
41#define ALARM1_STATUS (1 << 1)
42
43struct max8907_rtc {
44 struct max8907 *max8907;
45 struct regmap *regmap;
46 struct rtc_device *rtc_dev;
47 int irq;
48};
49
50static irqreturn_t max8907_irq_handler(int irq, void *data)
51{
52 struct max8907_rtc *rtc = data;
53
54 regmap_update_bits(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x7f, 0);
55
56 rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
57
58 return IRQ_HANDLED;
59}
60
61static void regs_to_tm(u8 *regs, struct rtc_time *tm)
62{
63 tm->tm_year = bcd2bin(regs[RTC_YEAR2]) * 100 +
64 bcd2bin(regs[RTC_YEAR1]) - 1900;
65 tm->tm_mon = bcd2bin(regs[RTC_MONTH] & 0x1f) - 1;
66 tm->tm_mday = bcd2bin(regs[RTC_DATE] & 0x3f);
67 tm->tm_wday = (regs[RTC_WEEKDAY] & 0x07) - 1;
68 if (regs[RTC_HOUR] & HOUR_12) {
69 tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x01f);
70 if (tm->tm_hour == 12)
71 tm->tm_hour = 0;
72 if (regs[RTC_HOUR] & HOUR_AM_PM)
73 tm->tm_hour += 12;
74 } else {
75 tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x03f);
76 }
77 tm->tm_min = bcd2bin(regs[RTC_MIN] & 0x7f);
78 tm->tm_sec = bcd2bin(regs[RTC_SEC] & 0x7f);
79}
80
81static void tm_to_regs(struct rtc_time *tm, u8 *regs)
82{
83 u8 high, low;
84
85 high = (tm->tm_year + 1900) / 100;
86 low = tm->tm_year % 100;
87 regs[RTC_YEAR2] = bin2bcd(high);
88 regs[RTC_YEAR1] = bin2bcd(low);
89 regs[RTC_MONTH] = bin2bcd(tm->tm_mon + 1);
90 regs[RTC_DATE] = bin2bcd(tm->tm_mday);
91 regs[RTC_WEEKDAY] = tm->tm_wday + 1;
92 regs[RTC_HOUR] = bin2bcd(tm->tm_hour);
93 regs[RTC_MIN] = bin2bcd(tm->tm_min);
94 regs[RTC_SEC] = bin2bcd(tm->tm_sec);
95}
96
97static int max8907_rtc_read_time(struct device *dev, struct rtc_time *tm)
98{
99 struct max8907_rtc *rtc = dev_get_drvdata(dev);
100 u8 regs[TIME_NUM];
101 int ret;
102
103 ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_RTC_SEC, regs,
104 TIME_NUM);
105 if (ret < 0)
106 return ret;
107
108 regs_to_tm(regs, tm);
109
110 return 0;
111}
112
113static int max8907_rtc_set_time(struct device *dev, struct rtc_time *tm)
114{
115 struct max8907_rtc *rtc = dev_get_drvdata(dev);
116 u8 regs[TIME_NUM];
117
118 tm_to_regs(tm, regs);
119
120 return regmap_bulk_write(rtc->regmap, MAX8907_REG_RTC_SEC, regs,
121 TIME_NUM);
122}
123
124static int max8907_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
125{
126 struct max8907_rtc *rtc = dev_get_drvdata(dev);
127 u8 regs[TIME_NUM];
128 unsigned int val;
129 int ret;
130
131 ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs,
132 TIME_NUM);
133 if (ret < 0)
134 return ret;
135
136 regs_to_tm(regs, &alrm->time);
137
138 ret = regmap_read(rtc->regmap, MAX8907_REG_ALARM0_CNTL, &val);
139 if (ret < 0)
140 return ret;
141
142 alrm->enabled = !!(val & 0x7f);
143
144 return 0;
145}
146
147static int max8907_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
148{
149 struct max8907_rtc *rtc = dev_get_drvdata(dev);
150 u8 regs[TIME_NUM];
151 int ret;
152
153 tm_to_regs(&alrm->time, regs);
154
155 /* Disable alarm while we update the target time */
156 ret = regmap_update_bits(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x7f, 0);
157 if (ret < 0)
158 return ret;
159
160 ret = regmap_bulk_write(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs,
161 TIME_NUM);
162 if (ret < 0)
163 return ret;
164
165 if (alrm->enabled)
166 ret = regmap_update_bits(rtc->regmap, MAX8907_REG_ALARM0_CNTL,
167 0x7f, 0x7f);
168
169 return ret;
170}
171
172static const struct rtc_class_ops max8907_rtc_ops = {
173 .read_time = max8907_rtc_read_time,
174 .set_time = max8907_rtc_set_time,
175 .read_alarm = max8907_rtc_read_alarm,
176 .set_alarm = max8907_rtc_set_alarm,
177};
178
179static int __devinit max8907_rtc_probe(struct platform_device *pdev)
180{
181 struct max8907 *max8907 = dev_get_drvdata(pdev->dev.parent);
182 struct max8907_rtc *rtc;
183 int ret;
184
185 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
186 if (!rtc)
187 return -ENOMEM;
188 platform_set_drvdata(pdev, rtc);
189
190 rtc->max8907 = max8907;
191 rtc->regmap = max8907->regmap_rtc;
192
193 rtc->rtc_dev = rtc_device_register("max8907-rtc", &pdev->dev,
194 &max8907_rtc_ops, THIS_MODULE);
195 if (IS_ERR(rtc->rtc_dev)) {
196 ret = PTR_ERR(rtc->rtc_dev);
197 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
198 return ret;
199 }
200
201 rtc->irq = regmap_irq_get_virq(max8907->irqc_rtc,
202 MAX8907_IRQ_RTC_ALARM0);
203 if (rtc->irq < 0) {
204 ret = rtc->irq;
205 goto err_unregister;
206 }
207
208 ret = request_threaded_irq(rtc->irq, NULL, max8907_irq_handler,
209 IRQF_ONESHOT, "max8907-alarm0", rtc);
210 if (ret < 0) {
211 dev_err(&pdev->dev, "Failed to request IRQ%d: %d\n",
212 rtc->irq, ret);
213 goto err_unregister;
214 }
215
216 return 0;
217
218err_unregister:
219 rtc_device_unregister(rtc->rtc_dev);
220 return ret;
221}
222
223static int __devexit max8907_rtc_remove(struct platform_device *pdev)
224{
225 struct max8907_rtc *rtc = platform_get_drvdata(pdev);
226
227 free_irq(rtc->irq, rtc);
228 rtc_device_unregister(rtc->rtc_dev);
229
230 return 0;
231}
232
233static struct platform_driver max8907_rtc_driver = {
234 .driver = {
235 .name = "max8907-rtc",
236 .owner = THIS_MODULE,
237 },
238 .probe = max8907_rtc_probe,
239 .remove = __devexit_p(max8907_rtc_remove),
240};
241module_platform_driver(max8907_rtc_driver);
242
243MODULE_DESCRIPTION("Maxim MAX8907 RTC driver");
244MODULE_LICENSE("GPL v2");