Merge tag 'v5.15-rc2' into spi-5.15
[platform/kernel/linux-rpi.git] / drivers / rtc / rtc-max8907.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * RTC driver for Maxim MAX8907
4  *
5  * Copyright (c) 2011-2012, NVIDIA Corporation.
6  *
7  * Based on drivers/rtc/rtc-max8925.c,
8  * Copyright (C) 2009-2010 Marvell International Ltd.
9  */
10
11 #include <linux/bcd.h>
12 #include <linux/i2c.h>
13 #include <linux/mfd/max8907.h>
14 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/regmap.h>
17 #include <linux/rtc.h>
18 #include <linux/slab.h>
19
20 enum {
21         RTC_SEC = 0,
22         RTC_MIN,
23         RTC_HOUR,
24         RTC_WEEKDAY,
25         RTC_DATE,
26         RTC_MONTH,
27         RTC_YEAR1,
28         RTC_YEAR2,
29 };
30
31 #define TIME_NUM                        8
32 #define ALARM_1SEC                      (1 << 7)
33 #define HOUR_12                         (1 << 7)
34 #define HOUR_AM_PM                      (1 << 5)
35 #define ALARM0_IRQ                      (1 << 3)
36 #define ALARM1_IRQ                      (1 << 2)
37 #define ALARM0_STATUS                   (1 << 2)
38 #define ALARM1_STATUS                   (1 << 1)
39
40 struct max8907_rtc {
41         struct max8907          *max8907;
42         struct regmap           *regmap;
43         struct rtc_device       *rtc_dev;
44         int                     irq;
45 };
46
47 static irqreturn_t max8907_irq_handler(int irq, void *data)
48 {
49         struct max8907_rtc *rtc = data;
50
51         regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0);
52
53         rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
54
55         return IRQ_HANDLED;
56 }
57
58 static void regs_to_tm(u8 *regs, struct rtc_time *tm)
59 {
60         tm->tm_year = bcd2bin(regs[RTC_YEAR2]) * 100 +
61                 bcd2bin(regs[RTC_YEAR1]) - 1900;
62         tm->tm_mon = bcd2bin(regs[RTC_MONTH] & 0x1f) - 1;
63         tm->tm_mday = bcd2bin(regs[RTC_DATE] & 0x3f);
64         tm->tm_wday = (regs[RTC_WEEKDAY] & 0x07);
65         if (regs[RTC_HOUR] & HOUR_12) {
66                 tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x01f);
67                 if (tm->tm_hour == 12)
68                         tm->tm_hour = 0;
69                 if (regs[RTC_HOUR] & HOUR_AM_PM)
70                         tm->tm_hour += 12;
71         } else {
72                 tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x03f);
73         }
74         tm->tm_min = bcd2bin(regs[RTC_MIN] & 0x7f);
75         tm->tm_sec = bcd2bin(regs[RTC_SEC] & 0x7f);
76 }
77
78 static void tm_to_regs(struct rtc_time *tm, u8 *regs)
79 {
80         u8 high, low;
81
82         high = (tm->tm_year + 1900) / 100;
83         low = tm->tm_year % 100;
84         regs[RTC_YEAR2] = bin2bcd(high);
85         regs[RTC_YEAR1] = bin2bcd(low);
86         regs[RTC_MONTH] = bin2bcd(tm->tm_mon + 1);
87         regs[RTC_DATE] = bin2bcd(tm->tm_mday);
88         regs[RTC_WEEKDAY] = tm->tm_wday;
89         regs[RTC_HOUR] = bin2bcd(tm->tm_hour);
90         regs[RTC_MIN] = bin2bcd(tm->tm_min);
91         regs[RTC_SEC] = bin2bcd(tm->tm_sec);
92 }
93
94 static int max8907_rtc_read_time(struct device *dev, struct rtc_time *tm)
95 {
96         struct max8907_rtc *rtc = dev_get_drvdata(dev);
97         u8 regs[TIME_NUM];
98         int ret;
99
100         ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_RTC_SEC, regs,
101                                TIME_NUM);
102         if (ret < 0)
103                 return ret;
104
105         regs_to_tm(regs, tm);
106
107         return 0;
108 }
109
110 static int max8907_rtc_set_time(struct device *dev, struct rtc_time *tm)
111 {
112         struct max8907_rtc *rtc = dev_get_drvdata(dev);
113         u8 regs[TIME_NUM];
114
115         tm_to_regs(tm, regs);
116
117         return regmap_bulk_write(rtc->regmap, MAX8907_REG_RTC_SEC, regs,
118                                  TIME_NUM);
119 }
120
121 static int max8907_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
122 {
123         struct max8907_rtc *rtc = dev_get_drvdata(dev);
124         u8 regs[TIME_NUM];
125         unsigned int val;
126         int ret;
127
128         ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs,
129                                TIME_NUM);
130         if (ret < 0)
131                 return ret;
132
133         regs_to_tm(regs, &alrm->time);
134
135         ret = regmap_read(rtc->regmap, MAX8907_REG_ALARM0_CNTL, &val);
136         if (ret < 0)
137                 return ret;
138
139         alrm->enabled = !!(val & 0x7f);
140
141         return 0;
142 }
143
144 static int max8907_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
145 {
146         struct max8907_rtc *rtc = dev_get_drvdata(dev);
147         u8 regs[TIME_NUM];
148         int ret;
149
150         tm_to_regs(&alrm->time, regs);
151
152         /* Disable alarm while we update the target time */
153         ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0);
154         if (ret < 0)
155                 return ret;
156
157         ret = regmap_bulk_write(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs,
158                                 TIME_NUM);
159         if (ret < 0)
160                 return ret;
161
162         if (alrm->enabled)
163                 ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x77);
164
165         return ret;
166 }
167
168 static const struct rtc_class_ops max8907_rtc_ops = {
169         .read_time      = max8907_rtc_read_time,
170         .set_time       = max8907_rtc_set_time,
171         .read_alarm     = max8907_rtc_read_alarm,
172         .set_alarm      = max8907_rtc_set_alarm,
173 };
174
175 static int max8907_rtc_probe(struct platform_device *pdev)
176 {
177         struct max8907 *max8907 = dev_get_drvdata(pdev->dev.parent);
178         struct max8907_rtc *rtc;
179         int ret;
180
181         rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
182         if (!rtc)
183                 return -ENOMEM;
184         platform_set_drvdata(pdev, rtc);
185
186         rtc->max8907 = max8907;
187         rtc->regmap = max8907->regmap_rtc;
188
189         rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8907-rtc",
190                                         &max8907_rtc_ops, THIS_MODULE);
191         if (IS_ERR(rtc->rtc_dev)) {
192                 ret = PTR_ERR(rtc->rtc_dev);
193                 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
194                 return ret;
195         }
196
197         rtc->irq = regmap_irq_get_virq(max8907->irqc_rtc,
198                                        MAX8907_IRQ_RTC_ALARM0);
199         if (rtc->irq < 0)
200                 return rtc->irq;
201
202         ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
203                                 max8907_irq_handler,
204                                 IRQF_ONESHOT, "max8907-alarm0", rtc);
205         if (ret < 0)
206                 dev_err(&pdev->dev, "Failed to request IRQ%d: %d\n",
207                         rtc->irq, ret);
208
209         return ret;
210 }
211
212 static struct platform_driver max8907_rtc_driver = {
213         .driver = {
214                 .name = "max8907-rtc",
215         },
216         .probe = max8907_rtc_probe,
217 };
218 module_platform_driver(max8907_rtc_driver);
219
220 MODULE_DESCRIPTION("Maxim MAX8907 RTC driver");
221 MODULE_LICENSE("GPL v2");