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