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Linux/drivers/rtc/rtc-max8998.c

  1 /*
  2  * RTC driver for Maxim MAX8998
  3  *
  4  * Copyright (C) 2010 Samsung Electronics Co.Ltd
  5  * Author: Minkyu Kang <mk7.kang@samsung.com>
  6  * Author: Joonyoung Shim <jy0922.shim@samsung.com>
  7  *
  8  *  This program is free software; you can redistribute  it and/or modify it
  9  *  under  the terms of  the GNU General  Public License as published by the
 10  *  Free Software Foundation;  either version 2 of the  License, or (at your
 11  *  option) any later version.
 12  *
 13  */
 14 
 15 #include <linux/module.h>
 16 #include <linux/i2c.h>
 17 #include <linux/slab.h>
 18 #include <linux/bcd.h>
 19 #include <linux/irqdomain.h>
 20 #include <linux/rtc.h>
 21 #include <linux/platform_device.h>
 22 #include <linux/mfd/max8998.h>
 23 #include <linux/mfd/max8998-private.h>
 24 #include <linux/delay.h>
 25 
 26 #define MAX8998_RTC_SEC                 0x00
 27 #define MAX8998_RTC_MIN                 0x01
 28 #define MAX8998_RTC_HOUR                0x02
 29 #define MAX8998_RTC_WEEKDAY             0x03
 30 #define MAX8998_RTC_DATE                0x04
 31 #define MAX8998_RTC_MONTH               0x05
 32 #define MAX8998_RTC_YEAR1               0x06
 33 #define MAX8998_RTC_YEAR2               0x07
 34 #define MAX8998_ALARM0_SEC              0x08
 35 #define MAX8998_ALARM0_MIN              0x09
 36 #define MAX8998_ALARM0_HOUR             0x0a
 37 #define MAX8998_ALARM0_WEEKDAY          0x0b
 38 #define MAX8998_ALARM0_DATE             0x0c
 39 #define MAX8998_ALARM0_MONTH            0x0d
 40 #define MAX8998_ALARM0_YEAR1            0x0e
 41 #define MAX8998_ALARM0_YEAR2            0x0f
 42 #define MAX8998_ALARM1_SEC              0x10
 43 #define MAX8998_ALARM1_MIN              0x11
 44 #define MAX8998_ALARM1_HOUR             0x12
 45 #define MAX8998_ALARM1_WEEKDAY          0x13
 46 #define MAX8998_ALARM1_DATE             0x14
 47 #define MAX8998_ALARM1_MONTH            0x15
 48 #define MAX8998_ALARM1_YEAR1            0x16
 49 #define MAX8998_ALARM1_YEAR2            0x17
 50 #define MAX8998_ALARM0_CONF             0x18
 51 #define MAX8998_ALARM1_CONF             0x19
 52 #define MAX8998_RTC_STATUS              0x1a
 53 #define MAX8998_WTSR_SMPL_CNTL          0x1b
 54 #define MAX8998_TEST                    0x1f
 55 
 56 #define HOUR_12                         (1 << 7)
 57 #define HOUR_PM                         (1 << 5)
 58 #define ALARM0_STATUS                   (1 << 1)
 59 #define ALARM1_STATUS                   (1 << 2)
 60 
 61 enum {
 62         RTC_SEC = 0,
 63         RTC_MIN,
 64         RTC_HOUR,
 65         RTC_WEEKDAY,
 66         RTC_DATE,
 67         RTC_MONTH,
 68         RTC_YEAR1,
 69         RTC_YEAR2,
 70 };
 71 
 72 struct max8998_rtc_info {
 73         struct device           *dev;
 74         struct max8998_dev      *max8998;
 75         struct i2c_client       *rtc;
 76         struct rtc_device       *rtc_dev;
 77         int irq;
 78         bool lp3974_bug_workaround;
 79 };
 80 
 81 static void max8998_data_to_tm(u8 *data, struct rtc_time *tm)
 82 {
 83         tm->tm_sec = bcd2bin(data[RTC_SEC]);
 84         tm->tm_min = bcd2bin(data[RTC_MIN]);
 85         if (data[RTC_HOUR] & HOUR_12) {
 86                 tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x1f);
 87                 if (data[RTC_HOUR] & HOUR_PM)
 88                         tm->tm_hour += 12;
 89         } else
 90                 tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);
 91 
 92         tm->tm_wday = data[RTC_WEEKDAY] & 0x07;
 93         tm->tm_mday = bcd2bin(data[RTC_DATE]);
 94         tm->tm_mon = bcd2bin(data[RTC_MONTH]);
 95         tm->tm_year = bcd2bin(data[RTC_YEAR1]) + bcd2bin(data[RTC_YEAR2]) * 100;
 96         tm->tm_year -= 1900;
 97 }
 98 
 99 static void max8998_tm_to_data(struct rtc_time *tm, u8 *data)
100 {
101         data[RTC_SEC] = bin2bcd(tm->tm_sec);
102         data[RTC_MIN] = bin2bcd(tm->tm_min);
103         data[RTC_HOUR] = bin2bcd(tm->tm_hour);
104         data[RTC_WEEKDAY] = tm->tm_wday;
105         data[RTC_DATE] = bin2bcd(tm->tm_mday);
106         data[RTC_MONTH] = bin2bcd(tm->tm_mon);
107         data[RTC_YEAR1] = bin2bcd(tm->tm_year % 100);
108         data[RTC_YEAR2] = bin2bcd((tm->tm_year + 1900) / 100);
109 }
110 
111 static int max8998_rtc_read_time(struct device *dev, struct rtc_time *tm)
112 {
113         struct max8998_rtc_info *info = dev_get_drvdata(dev);
114         u8 data[8];
115         int ret;
116 
117         ret = max8998_bulk_read(info->rtc, MAX8998_RTC_SEC, 8, data);
118         if (ret < 0)
119                 return ret;
120 
121         max8998_data_to_tm(data, tm);
122 
123         return rtc_valid_tm(tm);
124 }
125 
126 static int max8998_rtc_set_time(struct device *dev, struct rtc_time *tm)
127 {
128         struct max8998_rtc_info *info = dev_get_drvdata(dev);
129         u8 data[8];
130         int ret;
131 
132         max8998_tm_to_data(tm, data);
133 
134         ret = max8998_bulk_write(info->rtc, MAX8998_RTC_SEC, 8, data);
135 
136         if (info->lp3974_bug_workaround)
137                 msleep(2000);
138 
139         return ret;
140 }
141 
142 static int max8998_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
143 {
144         struct max8998_rtc_info *info = dev_get_drvdata(dev);
145         u8 data[8];
146         u8 val;
147         int ret;
148 
149         ret = max8998_bulk_read(info->rtc, MAX8998_ALARM0_SEC, 8, data);
150         if (ret < 0)
151                 return ret;
152 
153         max8998_data_to_tm(data, &alrm->time);
154 
155         ret = max8998_read_reg(info->rtc, MAX8998_ALARM0_CONF, &val);
156         if (ret < 0)
157                 return ret;
158 
159         alrm->enabled = !!val;
160 
161         ret = max8998_read_reg(info->rtc, MAX8998_RTC_STATUS, &val);
162         if (ret < 0)
163                 return ret;
164 
165         if (val & ALARM0_STATUS)
166                 alrm->pending = 1;
167         else
168                 alrm->pending = 0;
169 
170         return 0;
171 }
172 
173 static int max8998_rtc_stop_alarm(struct max8998_rtc_info *info)
174 {
175         int ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0);
176 
177         if (info->lp3974_bug_workaround)
178                 msleep(2000);
179 
180         return ret;
181 }
182 
183 static int max8998_rtc_start_alarm(struct max8998_rtc_info *info)
184 {
185         int ret;
186         u8 alarm0_conf = 0x77;
187 
188         /* LP3974 with delay bug chips has rtc alarm bugs with "MONTH" field */
189         if (info->lp3974_bug_workaround)
190                 alarm0_conf = 0x57;
191 
192         ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, alarm0_conf);
193 
194         if (info->lp3974_bug_workaround)
195                 msleep(2000);
196 
197         return ret;
198 }
199 
200 static int max8998_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
201 {
202         struct max8998_rtc_info *info = dev_get_drvdata(dev);
203         u8 data[8];
204         int ret;
205 
206         max8998_tm_to_data(&alrm->time, data);
207 
208         ret = max8998_rtc_stop_alarm(info);
209         if (ret < 0)
210                 return ret;
211 
212         ret = max8998_bulk_write(info->rtc, MAX8998_ALARM0_SEC, 8, data);
213         if (ret < 0)
214                 return ret;
215 
216         if (info->lp3974_bug_workaround)
217                 msleep(2000);
218 
219         if (alrm->enabled)
220                 ret = max8998_rtc_start_alarm(info);
221 
222         return ret;
223 }
224 
225 static int max8998_rtc_alarm_irq_enable(struct device *dev,
226                                         unsigned int enabled)
227 {
228         struct max8998_rtc_info *info = dev_get_drvdata(dev);
229 
230         if (enabled)
231                 return max8998_rtc_start_alarm(info);
232         else
233                 return max8998_rtc_stop_alarm(info);
234 }
235 
236 static irqreturn_t max8998_rtc_alarm_irq(int irq, void *data)
237 {
238         struct max8998_rtc_info *info = data;
239 
240         rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
241 
242         return IRQ_HANDLED;
243 }
244 
245 static const struct rtc_class_ops max8998_rtc_ops = {
246         .read_time = max8998_rtc_read_time,
247         .set_time = max8998_rtc_set_time,
248         .read_alarm = max8998_rtc_read_alarm,
249         .set_alarm = max8998_rtc_set_alarm,
250         .alarm_irq_enable = max8998_rtc_alarm_irq_enable,
251 };
252 
253 static int max8998_rtc_probe(struct platform_device *pdev)
254 {
255         struct max8998_dev *max8998 = dev_get_drvdata(pdev->dev.parent);
256         struct max8998_platform_data *pdata = max8998->pdata;
257         struct max8998_rtc_info *info;
258         int ret;
259 
260         info = devm_kzalloc(&pdev->dev, sizeof(struct max8998_rtc_info),
261                         GFP_KERNEL);
262         if (!info)
263                 return -ENOMEM;
264 
265         info->dev = &pdev->dev;
266         info->max8998 = max8998;
267         info->rtc = max8998->rtc;
268 
269         platform_set_drvdata(pdev, info);
270 
271         info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8998-rtc",
272                         &max8998_rtc_ops, THIS_MODULE);
273 
274         if (IS_ERR(info->rtc_dev)) {
275                 ret = PTR_ERR(info->rtc_dev);
276                 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
277                 return ret;
278         }
279 
280         if (!max8998->irq_domain)
281                 goto no_irq;
282 
283         info->irq = irq_create_mapping(max8998->irq_domain, MAX8998_IRQ_ALARM0);
284         if (!info->irq) {
285                 dev_warn(&pdev->dev, "Failed to map alarm IRQ\n");
286                 goto no_irq;
287         }
288 
289         ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
290                                 max8998_rtc_alarm_irq, 0, "rtc-alarm0", info);
291 
292         if (ret < 0)
293                 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
294                         info->irq, ret);
295 
296 no_irq:
297         dev_info(&pdev->dev, "RTC CHIP NAME: %s\n", pdev->id_entry->name);
298         if (pdata && pdata->rtc_delay) {
299                 info->lp3974_bug_workaround = true;
300                 dev_warn(&pdev->dev, "LP3974 with RTC REGERR option."
301                                 " RTC updates will be extremely slow.\n");
302         }
303 
304         return 0;
305 }
306 
307 static const struct platform_device_id max8998_rtc_id[] = {
308         { "max8998-rtc", TYPE_MAX8998 },
309         { "lp3974-rtc", TYPE_LP3974 },
310         { }
311 };
312 
313 static struct platform_driver max8998_rtc_driver = {
314         .driver         = {
315                 .name   = "max8998-rtc",
316                 .owner  = THIS_MODULE,
317         },
318         .probe          = max8998_rtc_probe,
319         .id_table       = max8998_rtc_id,
320 };
321 
322 module_platform_driver(max8998_rtc_driver);
323 
324 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
325 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
326 MODULE_DESCRIPTION("Maxim MAX8998 RTC driver");
327 MODULE_LICENSE("GPL");
328 

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