projects/linux·blob master · refs

321 lines · 7.6 KiB

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 <[email protected]>
7// Author: Joonyoung Shim <[email protected]>
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
55enum {
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
66struct 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
75static 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
93static 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
105static 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(info->rtc, MAX8998_RTC_SEC, 8, data);
112 if (ret < 0)
113 return ret;
114
115 max8998_data_to_tm(data, tm);
116
117 return 0;
118}
119
120static 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(info->rtc, MAX8998_RTC_SEC, 8, data);
129
130 if (info->lp3974_bug_workaround)
131 msleep(2000);
132
133 return ret;
134}
135
136static 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(info->rtc, MAX8998_ALARM0_SEC, 8, data);
144 if (ret < 0)
145 return ret;
146
147 max8998_data_to_tm(data, &alrm->time);
148
149 ret = max8998_read_reg(info->rtc, MAX8998_ALARM0_CONF, &val);
150 if (ret < 0)
151 return ret;
152
153 alrm->enabled = !!val;
154
155 ret = max8998_read_reg(info->rtc, MAX8998_RTC_STATUS, &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
167static int max8998_rtc_stop_alarm(struct max8998_rtc_info *info)
168{
169 int ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0);
170
171 if (info->lp3974_bug_workaround)
172 msleep(2000);
173
174 return ret;
175}
176
177static 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(info->rtc, MAX8998_ALARM0_CONF, alarm0_conf);
187
188 if (info->lp3974_bug_workaround)
189 msleep(2000);
190
191 return ret;
192}
193
194static 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(&alrm->time, data);
201
202 ret = max8998_rtc_stop_alarm(info);
203 if (ret < 0)
204 return ret;
205
206 ret = max8998_bulk_write(info->rtc, MAX8998_ALARM0_SEC, 8, data);
207 if (ret < 0)
208 return ret;
209
210 if (info->lp3974_bug_workaround)
211 msleep(2000);
212
213 if (alrm->enabled)
214 ret = max8998_rtc_start_alarm(info);
215
216 return ret;
217}
218
219static 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
230static irqreturn_t max8998_rtc_alarm_irq(int irq, void *data)
231{
232 struct max8998_rtc_info *info = data;
233
234 rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
235
236 return IRQ_HANDLED;
237}
238
239static 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
247static int max8998_rtc_probe(struct platform_device *pdev)
248{
249 struct max8998_dev *max8998 = dev_get_drvdata(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(&pdev->dev, 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, info);
264
265 info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8998-rtc",
266 &max8998_rtc_ops, THIS_MODULE);
267
268 if (IS_ERR(info->rtc_dev)) {
269 ret = PTR_ERR(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(max8998->irq_domain, 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(&pdev->dev, info->irq, NULL,
284 max8998_rtc_alarm_irq, 0, "rtc-alarm0", info);
285
286 if (ret < 0)
287 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
288 info->irq, ret);
289
290no_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
301static const struct platform_device_id max8998_rtc_id[] = {
302 { .name = "max8998-rtc", .driver_data = TYPE_MAX8998 },
303 { .name = "lp3974-rtc", .driver_data = TYPE_LP3974 },
304 { }
305};
306MODULE_DEVICE_TABLE(platform, max8998_rtc_id);
307
308static 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
316module_platform_driver(max8998_rtc_driver);
317
318MODULE_AUTHOR("Minkyu Kang <[email protected]>");
319MODULE_AUTHOR("Joonyoung Shim <[email protected]>");
320MODULE_DESCRIPTION("Maxim MAX8998 RTC driver");
321MODULE_LICENSE("GPL");