LP8758 pre version
[mlp-open-source/kernel.git] / drivers / rtc / rtc-lp8788.c
1 /*
2  * TI LP8788 MFD - rtc driver
3  *
4  * Copyright 2012 Texas Instruments
5  *
6  * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  *
12  */
14 #include <linux/err.h>
15 #include <linux/irqdomain.h>
16 #include <linux/mfd/lp8788.h>
17 #include <linux/module.h>
18 #include <linux/platform_device.h>
19 #include <linux/rtc.h>
20 #include <linux/slab.h>
22 /* register address */
23 #define LP8788_INTEN_3                  0x05
24 #define LP8788_RTC_UNLOCK               0x64
25 #define LP8788_RTC_SEC                  0x70
26 #define LP8788_ALM1_SEC                 0x77
27 #define LP8788_ALM1_EN                  0x7D
28 #define LP8788_ALM2_SEC                 0x7E
29 #define LP8788_ALM2_EN                  0x84
31 /* mask/shift bits */
32 #define LP8788_INT_RTC_ALM1_M           BIT(1)  /* Addr 05h */
33 #define LP8788_INT_RTC_ALM1_S           1
34 #define LP8788_INT_RTC_ALM2_M           BIT(2)  /* Addr 05h */
35 #define LP8788_INT_RTC_ALM2_S           2
36 #define LP8788_ALM_EN_M                 BIT(7)  /* Addr 7Dh or 84h */
37 #define LP8788_ALM_EN_S                 7
39 #define DEFAULT_ALARM_SEL               LP8788_ALARM_1
40 #define LP8788_MONTH_OFFSET             1
41 #define LP8788_BASE_YEAR                2000
42 #define MAX_WDAY_BITS                   7
43 #define LP8788_WDAY_SET                 1
44 #define RTC_UNLOCK                      0x1
45 #define RTC_LATCH                       0x2
46 #define ALARM_IRQ_FLAG                  (RTC_IRQF | RTC_AF)
48 enum lp8788_time {
49         LPTIME_SEC,
50         LPTIME_MIN,
51         LPTIME_HOUR,
52         LPTIME_MDAY,
53         LPTIME_MON,
54         LPTIME_YEAR,
55         LPTIME_WDAY,
56         LPTIME_MAX,
57 };
59 struct lp8788_rtc {
60         struct lp8788 *lp;
61         struct rtc_device *rdev;
62         enum lp8788_alarm_sel alarm;
63         int irq;
64 };
66 static const u8 addr_alarm_sec[LP8788_ALARM_MAX] = {
67         LP8788_ALM1_SEC,
68         LP8788_ALM2_SEC,
69 };
71 static const u8 addr_alarm_en[LP8788_ALARM_MAX] = {
72         LP8788_ALM1_EN,
73         LP8788_ALM2_EN,
74 };
76 static const u8 mask_alarm_en[LP8788_ALARM_MAX] = {
77         LP8788_INT_RTC_ALM1_M,
78         LP8788_INT_RTC_ALM2_M,
79 };
81 static const u8 shift_alarm_en[LP8788_ALARM_MAX] = {
82         LP8788_INT_RTC_ALM1_S,
83         LP8788_INT_RTC_ALM2_S,
84 };
86 static int _to_tm_wday(u8 lp8788_wday)
87 {
88         int i;
90         if (lp8788_wday == 0)
91                 return 0;
93         /* lookup defined weekday from read register value */
94         for (i = 0; i < MAX_WDAY_BITS; i++) {
95                 if ((lp8788_wday >> i) == LP8788_WDAY_SET)
96                         break;
97         }
99         return i + 1;
102 static inline int _to_lp8788_wday(int tm_wday)
104         return LP8788_WDAY_SET << (tm_wday - 1);
107 static void lp8788_rtc_unlock(struct lp8788 *lp)
109         lp8788_write_byte(lp, LP8788_RTC_UNLOCK, RTC_UNLOCK);
110         lp8788_write_byte(lp, LP8788_RTC_UNLOCK, RTC_LATCH);
113 static int lp8788_rtc_read_time(struct device *dev, struct rtc_time *tm)
115         struct lp8788_rtc *rtc = dev_get_drvdata(dev);
116         struct lp8788 *lp = rtc->lp;
117         u8 data[LPTIME_MAX];
118         int ret;
120         lp8788_rtc_unlock(lp);
122         ret = lp8788_read_multi_bytes(lp, LP8788_RTC_SEC, data, LPTIME_MAX);
123         if (ret)
124                 return ret;
126         tm->tm_sec  = data[LPTIME_SEC];
127         tm->tm_min  = data[LPTIME_MIN];
128         tm->tm_hour = data[LPTIME_HOUR];
129         tm->tm_mday = data[LPTIME_MDAY];
130         tm->tm_mon  = data[LPTIME_MON] - LP8788_MONTH_OFFSET;
131         tm->tm_year = data[LPTIME_YEAR] + LP8788_BASE_YEAR - 1900;
132         tm->tm_wday = _to_tm_wday(data[LPTIME_WDAY]);
134         return 0;
137 static int lp8788_rtc_set_time(struct device *dev, struct rtc_time *tm)
139         struct lp8788_rtc *rtc = dev_get_drvdata(dev);
140         struct lp8788 *lp = rtc->lp;
141         u8 data[LPTIME_MAX - 1];
142         int ret, i, year;
144         year = tm->tm_year + 1900 - LP8788_BASE_YEAR;
145         if (year < 0) {
146                 dev_err(lp->dev, "invalid year: %d\n", year);
147                 return -EINVAL;
148         }
150         /* because rtc weekday is a readonly register, do not update */
151         data[LPTIME_SEC]  = tm->tm_sec;
152         data[LPTIME_MIN]  = tm->tm_min;
153         data[LPTIME_HOUR] = tm->tm_hour;
154         data[LPTIME_MDAY] = tm->tm_mday;
155         data[LPTIME_MON]  = tm->tm_mon + LP8788_MONTH_OFFSET;
156         data[LPTIME_YEAR] = year;
158         for (i = 0; i < ARRAY_SIZE(data); i++) {
159                 ret = lp8788_write_byte(lp, LP8788_RTC_SEC + i, data[i]);
160                 if (ret)
161                         return ret;
162         }
164         return 0;
167 static int lp8788_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
169         struct lp8788_rtc *rtc = dev_get_drvdata(dev);
170         struct lp8788 *lp = rtc->lp;
171         struct rtc_time *tm = &alarm->time;
172         u8 addr, data[LPTIME_MAX];
173         int ret;
175         addr = addr_alarm_sec[rtc->alarm];
176         ret = lp8788_read_multi_bytes(lp, addr, data, LPTIME_MAX);
177         if (ret)
178                 return ret;
180         tm->tm_sec  = data[LPTIME_SEC];
181         tm->tm_min  = data[LPTIME_MIN];
182         tm->tm_hour = data[LPTIME_HOUR];
183         tm->tm_mday = data[LPTIME_MDAY];
184         tm->tm_mon  = data[LPTIME_MON] - LP8788_MONTH_OFFSET;
185         tm->tm_year = data[LPTIME_YEAR] + LP8788_BASE_YEAR - 1900;
186         tm->tm_wday = _to_tm_wday(data[LPTIME_WDAY]);
187         alarm->enabled = data[LPTIME_WDAY] & LP8788_ALM_EN_M;
189         return 0;
192 static int lp8788_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
194         struct lp8788_rtc *rtc = dev_get_drvdata(dev);
195         struct lp8788 *lp = rtc->lp;
196         struct rtc_time *tm = &alarm->time;
197         u8 addr, data[LPTIME_MAX];
198         int ret, i, year;
200         year = tm->tm_year + 1900 - LP8788_BASE_YEAR;
201         if (year < 0) {
202                 dev_err(lp->dev, "invalid year: %d\n", year);
203                 return -EINVAL;
204         }
206         data[LPTIME_SEC]  = tm->tm_sec;
207         data[LPTIME_MIN]  = tm->tm_min;
208         data[LPTIME_HOUR] = tm->tm_hour;
209         data[LPTIME_MDAY] = tm->tm_mday;
210         data[LPTIME_MON]  = tm->tm_mon + LP8788_MONTH_OFFSET;
211         data[LPTIME_YEAR] = year;
212         data[LPTIME_WDAY] = _to_lp8788_wday(tm->tm_wday);
214         for (i = 0; i < ARRAY_SIZE(data); i++) {
215                 addr = addr_alarm_sec[rtc->alarm] + i;
216                 ret = lp8788_write_byte(lp, addr, data[i]);
217                 if (ret)
218                         return ret;
219         }
221         alarm->enabled = 1;
222         addr = addr_alarm_en[rtc->alarm];
224         return lp8788_update_bits(lp, addr, LP8788_ALM_EN_M,
225                                 alarm->enabled << LP8788_ALM_EN_S);
228 static int lp8788_alarm_irq_enable(struct device *dev, unsigned int enable)
230         struct lp8788_rtc *rtc = dev_get_drvdata(dev);
231         struct lp8788 *lp = rtc->lp;
232         u8 mask, shift;
234         if (!rtc->irq)
235                 return -EIO;
237         mask = mask_alarm_en[rtc->alarm];
238         shift = shift_alarm_en[rtc->alarm];
240         return lp8788_update_bits(lp, LP8788_INTEN_3, mask, enable << shift);
243 static const struct rtc_class_ops lp8788_rtc_ops = {
244         .read_time = lp8788_rtc_read_time,
245         .set_time = lp8788_rtc_set_time,
246         .read_alarm = lp8788_read_alarm,
247         .set_alarm = lp8788_set_alarm,
248         .alarm_irq_enable = lp8788_alarm_irq_enable,
249 };
251 static irqreturn_t lp8788_alarm_irq_handler(int irq, void *ptr)
253         struct lp8788_rtc *rtc = ptr;
255         rtc_update_irq(rtc->rdev, 1, ALARM_IRQ_FLAG);
256         return IRQ_HANDLED;
259 static int lp8788_alarm_irq_register(struct platform_device *pdev,
260                                 struct lp8788_rtc *rtc)
262         struct resource *r;
263         struct lp8788 *lp = rtc->lp;
264         struct irq_domain *irqdm = lp->irqdm;
265         int irq;
267         rtc->irq = 0;
269         /* even the alarm IRQ number is not specified, rtc time should work */
270         r = platform_get_resource_byname(pdev, IORESOURCE_IRQ, LP8788_ALM_IRQ);
271         if (!r)
272                 return 0;
274         if (rtc->alarm == LP8788_ALARM_1)
275                 irq = r->start;
276         else
277                 irq = r->end;
279         rtc->irq = irq_create_mapping(irqdm, irq);
281         return devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
282                                 lp8788_alarm_irq_handler,
283                                 0, LP8788_ALM_IRQ, rtc);
286 static int lp8788_rtc_probe(struct platform_device *pdev)
288         struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
289         struct lp8788_rtc *rtc;
290         struct device *dev = &pdev->dev;
292         rtc = devm_kzalloc(dev, sizeof(struct lp8788_rtc), GFP_KERNEL);
293         if (!rtc)
294                 return -ENOMEM;
296         rtc->lp = lp;
297         rtc->alarm = lp->pdata ? lp->pdata->alarm_sel : DEFAULT_ALARM_SEL;
298         platform_set_drvdata(pdev, rtc);
300         device_init_wakeup(dev, 1);
302         rtc->rdev = devm_rtc_device_register(dev, "lp8788_rtc",
303                                         &lp8788_rtc_ops, THIS_MODULE);
304         if (IS_ERR(rtc->rdev)) {
305                 dev_err(dev, "can not register rtc device\n");
306                 return PTR_ERR(rtc->rdev);
307         }
309         if (lp8788_alarm_irq_register(pdev, rtc))
310                 dev_warn(lp->dev, "no rtc irq handler\n");
312         return 0;
315 static struct platform_driver lp8788_rtc_driver = {
316         .probe = lp8788_rtc_probe,
317         .driver = {
318                 .name = LP8788_DEV_RTC,
319                 .owner = THIS_MODULE,
320         },
321 };
322 module_platform_driver(lp8788_rtc_driver);
324 MODULE_DESCRIPTION("Texas Instruments LP8788 RTC Driver");
325 MODULE_AUTHOR("Milo Kim");
326 MODULE_LICENSE("GPL");
327 MODULE_ALIAS("platform:lp8788-rtc");