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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>
21
22
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
30
31
32#define LP8788_INT_RTC_ALM1_M BIT(1)
33#define LP8788_INT_RTC_ALM1_S 1
34#define LP8788_INT_RTC_ALM2_M BIT(2)
35#define LP8788_INT_RTC_ALM2_S 2
36#define LP8788_ALM_EN_M BIT(7)
37#define LP8788_ALM_EN_S 7
38
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)
47
48enum 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};
58
59struct lp8788_rtc {
60 struct lp8788 *lp;
61 struct rtc_device *rdev;
62 enum lp8788_alarm_sel alarm;
63 int irq;
64};
65
66static const u8 addr_alarm_sec[LP8788_ALARM_MAX] = {
67 LP8788_ALM1_SEC,
68 LP8788_ALM2_SEC,
69};
70
71static const u8 addr_alarm_en[LP8788_ALARM_MAX] = {
72 LP8788_ALM1_EN,
73 LP8788_ALM2_EN,
74};
75
76static const u8 mask_alarm_en[LP8788_ALARM_MAX] = {
77 LP8788_INT_RTC_ALM1_M,
78 LP8788_INT_RTC_ALM2_M,
79};
80
81static const u8 shift_alarm_en[LP8788_ALARM_MAX] = {
82 LP8788_INT_RTC_ALM1_S,
83 LP8788_INT_RTC_ALM2_S,
84};
85
86static int _to_tm_wday(u8 lp8788_wday)
87{
88 int i;
89
90 if (lp8788_wday == 0)
91 return 0;
92
93
94 for (i = 0; i < MAX_WDAY_BITS; i++) {
95 if ((lp8788_wday >> i) == LP8788_WDAY_SET)
96 break;
97 }
98
99 return i + 1;
100}
101
102static inline int _to_lp8788_wday(int tm_wday)
103{
104 return LP8788_WDAY_SET << (tm_wday - 1);
105}
106
107static void lp8788_rtc_unlock(struct lp8788 *lp)
108{
109 lp8788_write_byte(lp, LP8788_RTC_UNLOCK, RTC_UNLOCK);
110 lp8788_write_byte(lp, LP8788_RTC_UNLOCK, RTC_LATCH);
111}
112
113static int lp8788_rtc_read_time(struct device *dev, struct rtc_time *tm)
114{
115 struct lp8788_rtc *rtc = dev_get_drvdata(dev);
116 struct lp8788 *lp = rtc->lp;
117 u8 data[LPTIME_MAX];
118 int ret;
119
120 lp8788_rtc_unlock(lp);
121
122 ret = lp8788_read_multi_bytes(lp, LP8788_RTC_SEC, data, LPTIME_MAX);
123 if (ret)
124 return ret;
125
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]);
133
134 return 0;
135}
136
137static int lp8788_rtc_set_time(struct device *dev, struct rtc_time *tm)
138{
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;
143
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 }
149
150
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;
157
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 }
163
164 return 0;
165}
166
167static int lp8788_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
168{
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;
174
175 addr = addr_alarm_sec[rtc->alarm];
176 ret = lp8788_read_multi_bytes(lp, addr, data, LPTIME_MAX);
177 if (ret)
178 return ret;
179
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;
188
189 return 0;
190}
191
192static int lp8788_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
193{
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;
199
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 }
205
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);
213
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 }
220
221 alarm->enabled = 1;
222 addr = addr_alarm_en[rtc->alarm];
223
224 return lp8788_update_bits(lp, addr, LP8788_ALM_EN_M,
225 alarm->enabled << LP8788_ALM_EN_S);
226}
227
228static int lp8788_alarm_irq_enable(struct device *dev, unsigned int enable)
229{
230 struct lp8788_rtc *rtc = dev_get_drvdata(dev);
231 struct lp8788 *lp = rtc->lp;
232 u8 mask, shift;
233
234 if (!rtc->irq)
235 return -EIO;
236
237 mask = mask_alarm_en[rtc->alarm];
238 shift = shift_alarm_en[rtc->alarm];
239
240 return lp8788_update_bits(lp, LP8788_INTEN_3, mask, enable << shift);
241}
242
243static 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};
250
251static irqreturn_t lp8788_alarm_irq_handler(int irq, void *ptr)
252{
253 struct lp8788_rtc *rtc = ptr;
254
255 rtc_update_irq(rtc->rdev, 1, ALARM_IRQ_FLAG);
256 return IRQ_HANDLED;
257}
258
259static int lp8788_alarm_irq_register(struct platform_device *pdev,
260 struct lp8788_rtc *rtc)
261{
262 struct resource *r;
263 struct lp8788 *lp = rtc->lp;
264 struct irq_domain *irqdm = lp->irqdm;
265 int irq;
266
267 rtc->irq = 0;
268
269
270 r = platform_get_resource_byname(pdev, IORESOURCE_IRQ, LP8788_ALM_IRQ);
271 if (!r)
272 return 0;
273
274 if (rtc->alarm == LP8788_ALARM_1)
275 irq = r->start;
276 else
277 irq = r->end;
278
279 rtc->irq = irq_create_mapping(irqdm, irq);
280
281 return devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
282 lp8788_alarm_irq_handler,
283 0, LP8788_ALM_IRQ, rtc);
284}
285
286static int lp8788_rtc_probe(struct platform_device *pdev)
287{
288 struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
289 struct lp8788_rtc *rtc;
290 struct device *dev = &pdev->dev;
291
292 rtc = devm_kzalloc(dev, sizeof(struct lp8788_rtc), GFP_KERNEL);
293 if (!rtc)
294 return -ENOMEM;
295
296 rtc->lp = lp;
297 rtc->alarm = lp->pdata ? lp->pdata->alarm_sel : DEFAULT_ALARM_SEL;
298 platform_set_drvdata(pdev, rtc);
299
300 device_init_wakeup(dev, 1);
301
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 }
308
309 if (lp8788_alarm_irq_register(pdev, rtc))
310 dev_warn(lp->dev, "no rtc irq handler\n");
311
312 return 0;
313}
314
315static struct platform_driver lp8788_rtc_driver = {
316 .probe = lp8788_rtc_probe,
317 .driver = {
318 .name = LP8788_DEV_RTC,
319 .owner = THIS_MODULE,
320 },
321};
322module_platform_driver(lp8788_rtc_driver);
323
324MODULE_DESCRIPTION("Texas Instruments LP8788 RTC Driver");
325MODULE_AUTHOR("Milo Kim");
326MODULE_LICENSE("GPL");
327MODULE_ALIAS("platform:lp8788-rtc");
328
