1
2
3
4
5
6
7
8
9
10
11
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_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 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);
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;
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
156 ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 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_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x77);
167
168 return ret;
169}
170
171static const struct rtc_class_ops max8907_rtc_ops = {
172 .read_time = max8907_rtc_read_time,
173 .set_time = max8907_rtc_set_time,
174 .read_alarm = max8907_rtc_read_alarm,
175 .set_alarm = max8907_rtc_set_alarm,
176};
177
178static int max8907_rtc_probe(struct platform_device *pdev)
179{
180 struct max8907 *max8907 = dev_get_drvdata(pdev->dev.parent);
181 struct max8907_rtc *rtc;
182 int ret;
183
184 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
185 if (!rtc)
186 return -ENOMEM;
187 platform_set_drvdata(pdev, rtc);
188
189 rtc->max8907 = max8907;
190 rtc->regmap = max8907->regmap_rtc;
191
192 rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8907-rtc",
193 &max8907_rtc_ops, THIS_MODULE);
194 if (IS_ERR(rtc->rtc_dev)) {
195 ret = PTR_ERR(rtc->rtc_dev);
196 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
197 return ret;
198 }
199
200 rtc->irq = regmap_irq_get_virq(max8907->irqc_rtc,
201 MAX8907_IRQ_RTC_ALARM0);
202 if (rtc->irq < 0)
203 return rtc->irq;
204
205 ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
206 max8907_irq_handler,
207 IRQF_ONESHOT, "max8907-alarm0", rtc);
208 if (ret < 0)
209 dev_err(&pdev->dev, "Failed to request IRQ%d: %d\n",
210 rtc->irq, ret);
211
212 return ret;
213}
214
215static struct platform_driver max8907_rtc_driver = {
216 .driver = {
217 .name = "max8907-rtc",
218 },
219 .probe = max8907_rtc_probe,
220};
221module_platform_driver(max8907_rtc_driver);
222
223MODULE_DESCRIPTION("Maxim MAX8907 RTC driver");
224MODULE_LICENSE("GPL v2");
225
