1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | // |
3 | // RTC driver for Maxim MAX8998 |
4 | // |
5 | // Copyright (C) 2010 Samsung Electronics Co.Ltd |
6 | // Author: Minkyu Kang <mk7.kang@samsung.com> |
7 | // Author: Joonyoung Shim <jy0922.shim@samsung.com> |
8 | |
9 | #include <linux/module.h> |
10 | #include <linux/i2c.h> |
11 | #include <linux/slab.h> |
12 | #include <linux/bcd.h> |
13 | #include <linux/irqdomain.h> |
14 | #include <linux/rtc.h> |
15 | #include <linux/platform_device.h> |
16 | #include <linux/mfd/max8998.h> |
17 | #include <linux/mfd/max8998-private.h> |
18 | #include <linux/delay.h> |
19 | |
20 | #define MAX8998_RTC_SEC 0x00 |
21 | #define MAX8998_RTC_MIN 0x01 |
22 | #define MAX8998_RTC_HOUR 0x02 |
23 | #define MAX8998_RTC_WEEKDAY 0x03 |
24 | #define MAX8998_RTC_DATE 0x04 |
25 | #define MAX8998_RTC_MONTH 0x05 |
26 | #define MAX8998_RTC_YEAR1 0x06 |
27 | #define MAX8998_RTC_YEAR2 0x07 |
28 | #define MAX8998_ALARM0_SEC 0x08 |
29 | #define MAX8998_ALARM0_MIN 0x09 |
30 | #define MAX8998_ALARM0_HOUR 0x0a |
31 | #define MAX8998_ALARM0_WEEKDAY 0x0b |
32 | #define MAX8998_ALARM0_DATE 0x0c |
33 | #define MAX8998_ALARM0_MONTH 0x0d |
34 | #define MAX8998_ALARM0_YEAR1 0x0e |
35 | #define MAX8998_ALARM0_YEAR2 0x0f |
36 | #define MAX8998_ALARM1_SEC 0x10 |
37 | #define MAX8998_ALARM1_MIN 0x11 |
38 | #define MAX8998_ALARM1_HOUR 0x12 |
39 | #define MAX8998_ALARM1_WEEKDAY 0x13 |
40 | #define MAX8998_ALARM1_DATE 0x14 |
41 | #define MAX8998_ALARM1_MONTH 0x15 |
42 | #define MAX8998_ALARM1_YEAR1 0x16 |
43 | #define MAX8998_ALARM1_YEAR2 0x17 |
44 | #define MAX8998_ALARM0_CONF 0x18 |
45 | #define MAX8998_ALARM1_CONF 0x19 |
46 | #define MAX8998_RTC_STATUS 0x1a |
47 | #define MAX8998_WTSR_SMPL_CNTL 0x1b |
48 | #define MAX8998_TEST 0x1f |
49 | |
50 | #define HOUR_12 (1 << 7) |
51 | #define HOUR_PM (1 << 5) |
52 | #define ALARM0_STATUS (1 << 1) |
53 | #define ALARM1_STATUS (1 << 2) |
54 | |
55 | enum { |
56 | RTC_SEC = 0, |
57 | RTC_MIN, |
58 | RTC_HOUR, |
59 | RTC_WEEKDAY, |
60 | RTC_DATE, |
61 | RTC_MONTH, |
62 | RTC_YEAR1, |
63 | RTC_YEAR2, |
64 | }; |
65 | |
66 | struct max8998_rtc_info { |
67 | struct device *dev; |
68 | struct max8998_dev *max8998; |
69 | struct i2c_client *rtc; |
70 | struct rtc_device *rtc_dev; |
71 | int irq; |
72 | bool lp3974_bug_workaround; |
73 | }; |
74 | |
75 | static void max8998_data_to_tm(u8 *data, struct rtc_time *tm) |
76 | { |
77 | tm->tm_sec = bcd2bin(data[RTC_SEC]); |
78 | tm->tm_min = bcd2bin(data[RTC_MIN]); |
79 | if (data[RTC_HOUR] & HOUR_12) { |
80 | tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x1f); |
81 | if (data[RTC_HOUR] & HOUR_PM) |
82 | tm->tm_hour += 12; |
83 | } else |
84 | tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f); |
85 | |
86 | tm->tm_wday = data[RTC_WEEKDAY] & 0x07; |
87 | tm->tm_mday = bcd2bin(data[RTC_DATE]); |
88 | tm->tm_mon = bcd2bin(data[RTC_MONTH]); |
89 | tm->tm_year = bcd2bin(data[RTC_YEAR1]) + bcd2bin(data[RTC_YEAR2]) * 100; |
90 | tm->tm_year -= 1900; |
91 | } |
92 | |
93 | static void max8998_tm_to_data(struct rtc_time *tm, u8 *data) |
94 | { |
95 | data[RTC_SEC] = bin2bcd(tm->tm_sec); |
96 | data[RTC_MIN] = bin2bcd(tm->tm_min); |
97 | data[RTC_HOUR] = bin2bcd(tm->tm_hour); |
98 | data[RTC_WEEKDAY] = tm->tm_wday; |
99 | data[RTC_DATE] = bin2bcd(tm->tm_mday); |
100 | data[RTC_MONTH] = bin2bcd(tm->tm_mon); |
101 | data[RTC_YEAR1] = bin2bcd(tm->tm_year % 100); |
102 | data[RTC_YEAR2] = bin2bcd((tm->tm_year + 1900) / 100); |
103 | } |
104 | |
105 | static int max8998_rtc_read_time(struct device *dev, struct rtc_time *tm) |
106 | { |
107 | struct max8998_rtc_info *info = dev_get_drvdata(dev); |
108 | u8 data[8]; |
109 | int ret; |
110 | |
111 | ret = max8998_bulk_read(i2c: info->rtc, MAX8998_RTC_SEC, count: 8, buf: data); |
112 | if (ret < 0) |
113 | return ret; |
114 | |
115 | max8998_data_to_tm(data, tm); |
116 | |
117 | return 0; |
118 | } |
119 | |
120 | static int max8998_rtc_set_time(struct device *dev, struct rtc_time *tm) |
121 | { |
122 | struct max8998_rtc_info *info = dev_get_drvdata(dev); |
123 | u8 data[8]; |
124 | int ret; |
125 | |
126 | max8998_tm_to_data(tm, data); |
127 | |
128 | ret = max8998_bulk_write(i2c: info->rtc, MAX8998_RTC_SEC, count: 8, buf: data); |
129 | |
130 | if (info->lp3974_bug_workaround) |
131 | msleep(msecs: 2000); |
132 | |
133 | return ret; |
134 | } |
135 | |
136 | static int max8998_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) |
137 | { |
138 | struct max8998_rtc_info *info = dev_get_drvdata(dev); |
139 | u8 data[8]; |
140 | u8 val; |
141 | int ret; |
142 | |
143 | ret = max8998_bulk_read(i2c: info->rtc, MAX8998_ALARM0_SEC, count: 8, buf: data); |
144 | if (ret < 0) |
145 | return ret; |
146 | |
147 | max8998_data_to_tm(data, tm: &alrm->time); |
148 | |
149 | ret = max8998_read_reg(i2c: info->rtc, MAX8998_ALARM0_CONF, dest: &val); |
150 | if (ret < 0) |
151 | return ret; |
152 | |
153 | alrm->enabled = !!val; |
154 | |
155 | ret = max8998_read_reg(i2c: info->rtc, MAX8998_RTC_STATUS, dest: &val); |
156 | if (ret < 0) |
157 | return ret; |
158 | |
159 | if (val & ALARM0_STATUS) |
160 | alrm->pending = 1; |
161 | else |
162 | alrm->pending = 0; |
163 | |
164 | return 0; |
165 | } |
166 | |
167 | static int max8998_rtc_stop_alarm(struct max8998_rtc_info *info) |
168 | { |
169 | int ret = max8998_write_reg(i2c: info->rtc, MAX8998_ALARM0_CONF, value: 0); |
170 | |
171 | if (info->lp3974_bug_workaround) |
172 | msleep(msecs: 2000); |
173 | |
174 | return ret; |
175 | } |
176 | |
177 | static int max8998_rtc_start_alarm(struct max8998_rtc_info *info) |
178 | { |
179 | int ret; |
180 | u8 alarm0_conf = 0x77; |
181 | |
182 | /* LP3974 with delay bug chips has rtc alarm bugs with "MONTH" field */ |
183 | if (info->lp3974_bug_workaround) |
184 | alarm0_conf = 0x57; |
185 | |
186 | ret = max8998_write_reg(i2c: info->rtc, MAX8998_ALARM0_CONF, value: alarm0_conf); |
187 | |
188 | if (info->lp3974_bug_workaround) |
189 | msleep(msecs: 2000); |
190 | |
191 | return ret; |
192 | } |
193 | |
194 | static int max8998_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) |
195 | { |
196 | struct max8998_rtc_info *info = dev_get_drvdata(dev); |
197 | u8 data[8]; |
198 | int ret; |
199 | |
200 | max8998_tm_to_data(tm: &alrm->time, data); |
201 | |
202 | ret = max8998_rtc_stop_alarm(info); |
203 | if (ret < 0) |
204 | return ret; |
205 | |
206 | ret = max8998_bulk_write(i2c: info->rtc, MAX8998_ALARM0_SEC, count: 8, buf: data); |
207 | if (ret < 0) |
208 | return ret; |
209 | |
210 | if (info->lp3974_bug_workaround) |
211 | msleep(msecs: 2000); |
212 | |
213 | if (alrm->enabled) |
214 | ret = max8998_rtc_start_alarm(info); |
215 | |
216 | return ret; |
217 | } |
218 | |
219 | static int max8998_rtc_alarm_irq_enable(struct device *dev, |
220 | unsigned int enabled) |
221 | { |
222 | struct max8998_rtc_info *info = dev_get_drvdata(dev); |
223 | |
224 | if (enabled) |
225 | return max8998_rtc_start_alarm(info); |
226 | else |
227 | return max8998_rtc_stop_alarm(info); |
228 | } |
229 | |
230 | static irqreturn_t max8998_rtc_alarm_irq(int irq, void *data) |
231 | { |
232 | struct max8998_rtc_info *info = data; |
233 | |
234 | rtc_update_irq(rtc: info->rtc_dev, num: 1, RTC_IRQF | RTC_AF); |
235 | |
236 | return IRQ_HANDLED; |
237 | } |
238 | |
239 | static const struct rtc_class_ops max8998_rtc_ops = { |
240 | .read_time = max8998_rtc_read_time, |
241 | .set_time = max8998_rtc_set_time, |
242 | .read_alarm = max8998_rtc_read_alarm, |
243 | .set_alarm = max8998_rtc_set_alarm, |
244 | .alarm_irq_enable = max8998_rtc_alarm_irq_enable, |
245 | }; |
246 | |
247 | static int max8998_rtc_probe(struct platform_device *pdev) |
248 | { |
249 | struct max8998_dev *max8998 = dev_get_drvdata(dev: pdev->dev.parent); |
250 | struct max8998_platform_data *pdata = max8998->pdata; |
251 | struct max8998_rtc_info *info; |
252 | int ret; |
253 | |
254 | info = devm_kzalloc(dev: &pdev->dev, size: sizeof(struct max8998_rtc_info), |
255 | GFP_KERNEL); |
256 | if (!info) |
257 | return -ENOMEM; |
258 | |
259 | info->dev = &pdev->dev; |
260 | info->max8998 = max8998; |
261 | info->rtc = max8998->rtc; |
262 | |
263 | platform_set_drvdata(pdev, data: info); |
264 | |
265 | info->rtc_dev = devm_rtc_device_register(dev: &pdev->dev, name: "max8998-rtc" , |
266 | ops: &max8998_rtc_ops, THIS_MODULE); |
267 | |
268 | if (IS_ERR(ptr: info->rtc_dev)) { |
269 | ret = PTR_ERR(ptr: info->rtc_dev); |
270 | dev_err(&pdev->dev, "Failed to register RTC device: %d\n" , ret); |
271 | return ret; |
272 | } |
273 | |
274 | if (!max8998->irq_domain) |
275 | goto no_irq; |
276 | |
277 | info->irq = irq_create_mapping(host: max8998->irq_domain, hwirq: MAX8998_IRQ_ALARM0); |
278 | if (!info->irq) { |
279 | dev_warn(&pdev->dev, "Failed to map alarm IRQ\n" ); |
280 | goto no_irq; |
281 | } |
282 | |
283 | ret = devm_request_threaded_irq(dev: &pdev->dev, irq: info->irq, NULL, |
284 | thread_fn: max8998_rtc_alarm_irq, irqflags: 0, devname: "rtc-alarm0" , dev_id: info); |
285 | |
286 | if (ret < 0) |
287 | dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n" , |
288 | info->irq, ret); |
289 | |
290 | no_irq: |
291 | dev_info(&pdev->dev, "RTC CHIP NAME: %s\n" , pdev->id_entry->name); |
292 | if (pdata && pdata->rtc_delay) { |
293 | info->lp3974_bug_workaround = true; |
294 | dev_warn(&pdev->dev, "LP3974 with RTC REGERR option." |
295 | " RTC updates will be extremely slow.\n" ); |
296 | } |
297 | |
298 | return 0; |
299 | } |
300 | |
301 | static const struct platform_device_id max8998_rtc_id[] = { |
302 | { "max8998-rtc" , TYPE_MAX8998 }, |
303 | { "lp3974-rtc" , TYPE_LP3974 }, |
304 | { } |
305 | }; |
306 | MODULE_DEVICE_TABLE(platform, max8998_rtc_id); |
307 | |
308 | static struct platform_driver max8998_rtc_driver = { |
309 | .driver = { |
310 | .name = "max8998-rtc" , |
311 | }, |
312 | .probe = max8998_rtc_probe, |
313 | .id_table = max8998_rtc_id, |
314 | }; |
315 | |
316 | module_platform_driver(max8998_rtc_driver); |
317 | |
318 | MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>" ); |
319 | MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>" ); |
320 | MODULE_DESCRIPTION("Maxim MAX8998 RTC driver" ); |
321 | MODULE_LICENSE("GPL" ); |
322 | |