1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * TI LP8788 MFD - rtc driver |
4 | * |
5 | * Copyright 2012 Texas Instruments |
6 | * |
7 | * Author: Milo(Woogyom) Kim <milo.kim@ti.com> |
8 | */ |
9 | |
10 | #include <linux/err.h> |
11 | #include <linux/irqdomain.h> |
12 | #include <linux/mfd/lp8788.h> |
13 | #include <linux/module.h> |
14 | #include <linux/platform_device.h> |
15 | #include <linux/rtc.h> |
16 | #include <linux/slab.h> |
17 | |
18 | /* register address */ |
19 | #define LP8788_INTEN_3 0x05 |
20 | #define LP8788_RTC_UNLOCK 0x64 |
21 | #define LP8788_RTC_SEC 0x70 |
22 | #define LP8788_ALM1_SEC 0x77 |
23 | #define LP8788_ALM1_EN 0x7D |
24 | #define LP8788_ALM2_SEC 0x7E |
25 | #define LP8788_ALM2_EN 0x84 |
26 | |
27 | /* mask/shift bits */ |
28 | #define LP8788_INT_RTC_ALM1_M BIT(1) /* Addr 05h */ |
29 | #define LP8788_INT_RTC_ALM1_S 1 |
30 | #define LP8788_INT_RTC_ALM2_M BIT(2) /* Addr 05h */ |
31 | #define LP8788_INT_RTC_ALM2_S 2 |
32 | #define LP8788_ALM_EN_M BIT(7) /* Addr 7Dh or 84h */ |
33 | #define LP8788_ALM_EN_S 7 |
34 | |
35 | #define DEFAULT_ALARM_SEL LP8788_ALARM_1 |
36 | #define LP8788_MONTH_OFFSET 1 |
37 | #define LP8788_BASE_YEAR 2000 |
38 | #define MAX_WDAY_BITS 7 |
39 | #define LP8788_WDAY_SET 1 |
40 | #define RTC_UNLOCK 0x1 |
41 | #define RTC_LATCH 0x2 |
42 | #define ALARM_IRQ_FLAG (RTC_IRQF | RTC_AF) |
43 | |
44 | enum lp8788_time { |
45 | LPTIME_SEC, |
46 | LPTIME_MIN, |
47 | LPTIME_HOUR, |
48 | LPTIME_MDAY, |
49 | LPTIME_MON, |
50 | LPTIME_YEAR, |
51 | LPTIME_WDAY, |
52 | LPTIME_MAX, |
53 | }; |
54 | |
55 | struct lp8788_rtc { |
56 | struct lp8788 *lp; |
57 | struct rtc_device *rdev; |
58 | enum lp8788_alarm_sel alarm; |
59 | int irq; |
60 | }; |
61 | |
62 | static const u8 addr_alarm_sec[LP8788_ALARM_MAX] = { |
63 | LP8788_ALM1_SEC, |
64 | LP8788_ALM2_SEC, |
65 | }; |
66 | |
67 | static const u8 addr_alarm_en[LP8788_ALARM_MAX] = { |
68 | LP8788_ALM1_EN, |
69 | LP8788_ALM2_EN, |
70 | }; |
71 | |
72 | static const u8 mask_alarm_en[LP8788_ALARM_MAX] = { |
73 | LP8788_INT_RTC_ALM1_M, |
74 | LP8788_INT_RTC_ALM2_M, |
75 | }; |
76 | |
77 | static const u8 shift_alarm_en[LP8788_ALARM_MAX] = { |
78 | LP8788_INT_RTC_ALM1_S, |
79 | LP8788_INT_RTC_ALM2_S, |
80 | }; |
81 | |
82 | static int _to_tm_wday(u8 lp8788_wday) |
83 | { |
84 | int i; |
85 | |
86 | if (lp8788_wday == 0) |
87 | return 0; |
88 | |
89 | /* lookup defined weekday from read register value */ |
90 | for (i = 0; i < MAX_WDAY_BITS; i++) { |
91 | if ((lp8788_wday >> i) == LP8788_WDAY_SET) |
92 | break; |
93 | } |
94 | |
95 | return i + 1; |
96 | } |
97 | |
98 | static inline int _to_lp8788_wday(int tm_wday) |
99 | { |
100 | return LP8788_WDAY_SET << (tm_wday - 1); |
101 | } |
102 | |
103 | static void lp8788_rtc_unlock(struct lp8788 *lp) |
104 | { |
105 | lp8788_write_byte(lp, LP8788_RTC_UNLOCK, RTC_UNLOCK); |
106 | lp8788_write_byte(lp, LP8788_RTC_UNLOCK, RTC_LATCH); |
107 | } |
108 | |
109 | static int lp8788_rtc_read_time(struct device *dev, struct rtc_time *tm) |
110 | { |
111 | struct lp8788_rtc *rtc = dev_get_drvdata(dev); |
112 | struct lp8788 *lp = rtc->lp; |
113 | u8 data[LPTIME_MAX]; |
114 | int ret; |
115 | |
116 | lp8788_rtc_unlock(lp); |
117 | |
118 | ret = lp8788_read_multi_bytes(lp, LP8788_RTC_SEC, data, count: LPTIME_MAX); |
119 | if (ret) |
120 | return ret; |
121 | |
122 | tm->tm_sec = data[LPTIME_SEC]; |
123 | tm->tm_min = data[LPTIME_MIN]; |
124 | tm->tm_hour = data[LPTIME_HOUR]; |
125 | tm->tm_mday = data[LPTIME_MDAY]; |
126 | tm->tm_mon = data[LPTIME_MON] - LP8788_MONTH_OFFSET; |
127 | tm->tm_year = data[LPTIME_YEAR] + LP8788_BASE_YEAR - 1900; |
128 | tm->tm_wday = _to_tm_wday(lp8788_wday: data[LPTIME_WDAY]); |
129 | |
130 | return 0; |
131 | } |
132 | |
133 | static int lp8788_rtc_set_time(struct device *dev, struct rtc_time *tm) |
134 | { |
135 | struct lp8788_rtc *rtc = dev_get_drvdata(dev); |
136 | struct lp8788 *lp = rtc->lp; |
137 | u8 data[LPTIME_MAX - 1]; |
138 | int ret, i, year; |
139 | |
140 | year = tm->tm_year + 1900 - LP8788_BASE_YEAR; |
141 | if (year < 0) { |
142 | dev_err(lp->dev, "invalid year: %d\n" , year); |
143 | return -EINVAL; |
144 | } |
145 | |
146 | /* because rtc weekday is a readonly register, do not update */ |
147 | data[LPTIME_SEC] = tm->tm_sec; |
148 | data[LPTIME_MIN] = tm->tm_min; |
149 | data[LPTIME_HOUR] = tm->tm_hour; |
150 | data[LPTIME_MDAY] = tm->tm_mday; |
151 | data[LPTIME_MON] = tm->tm_mon + LP8788_MONTH_OFFSET; |
152 | data[LPTIME_YEAR] = year; |
153 | |
154 | for (i = 0; i < ARRAY_SIZE(data); i++) { |
155 | ret = lp8788_write_byte(lp, LP8788_RTC_SEC + i, data: data[i]); |
156 | if (ret) |
157 | return ret; |
158 | } |
159 | |
160 | return 0; |
161 | } |
162 | |
163 | static int lp8788_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) |
164 | { |
165 | struct lp8788_rtc *rtc = dev_get_drvdata(dev); |
166 | struct lp8788 *lp = rtc->lp; |
167 | struct rtc_time *tm = &alarm->time; |
168 | u8 addr, data[LPTIME_MAX]; |
169 | int ret; |
170 | |
171 | addr = addr_alarm_sec[rtc->alarm]; |
172 | ret = lp8788_read_multi_bytes(lp, reg: addr, data, count: LPTIME_MAX); |
173 | if (ret) |
174 | return ret; |
175 | |
176 | tm->tm_sec = data[LPTIME_SEC]; |
177 | tm->tm_min = data[LPTIME_MIN]; |
178 | tm->tm_hour = data[LPTIME_HOUR]; |
179 | tm->tm_mday = data[LPTIME_MDAY]; |
180 | tm->tm_mon = data[LPTIME_MON] - LP8788_MONTH_OFFSET; |
181 | tm->tm_year = data[LPTIME_YEAR] + LP8788_BASE_YEAR - 1900; |
182 | tm->tm_wday = _to_tm_wday(lp8788_wday: data[LPTIME_WDAY]); |
183 | alarm->enabled = data[LPTIME_WDAY] & LP8788_ALM_EN_M; |
184 | |
185 | return 0; |
186 | } |
187 | |
188 | static int lp8788_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) |
189 | { |
190 | struct lp8788_rtc *rtc = dev_get_drvdata(dev); |
191 | struct lp8788 *lp = rtc->lp; |
192 | struct rtc_time *tm = &alarm->time; |
193 | u8 addr, data[LPTIME_MAX]; |
194 | int ret, i, year; |
195 | |
196 | year = tm->tm_year + 1900 - LP8788_BASE_YEAR; |
197 | if (year < 0) { |
198 | dev_err(lp->dev, "invalid year: %d\n" , year); |
199 | return -EINVAL; |
200 | } |
201 | |
202 | data[LPTIME_SEC] = tm->tm_sec; |
203 | data[LPTIME_MIN] = tm->tm_min; |
204 | data[LPTIME_HOUR] = tm->tm_hour; |
205 | data[LPTIME_MDAY] = tm->tm_mday; |
206 | data[LPTIME_MON] = tm->tm_mon + LP8788_MONTH_OFFSET; |
207 | data[LPTIME_YEAR] = year; |
208 | data[LPTIME_WDAY] = _to_lp8788_wday(tm_wday: tm->tm_wday); |
209 | |
210 | for (i = 0; i < ARRAY_SIZE(data); i++) { |
211 | addr = addr_alarm_sec[rtc->alarm] + i; |
212 | ret = lp8788_write_byte(lp, reg: addr, data: data[i]); |
213 | if (ret) |
214 | return ret; |
215 | } |
216 | |
217 | alarm->enabled = 1; |
218 | addr = addr_alarm_en[rtc->alarm]; |
219 | |
220 | return lp8788_update_bits(lp, reg: addr, LP8788_ALM_EN_M, |
221 | data: alarm->enabled << LP8788_ALM_EN_S); |
222 | } |
223 | |
224 | static int lp8788_alarm_irq_enable(struct device *dev, unsigned int enable) |
225 | { |
226 | struct lp8788_rtc *rtc = dev_get_drvdata(dev); |
227 | struct lp8788 *lp = rtc->lp; |
228 | u8 mask, shift; |
229 | |
230 | if (!rtc->irq) |
231 | return -EIO; |
232 | |
233 | mask = mask_alarm_en[rtc->alarm]; |
234 | shift = shift_alarm_en[rtc->alarm]; |
235 | |
236 | return lp8788_update_bits(lp, LP8788_INTEN_3, mask, data: enable << shift); |
237 | } |
238 | |
239 | static const struct rtc_class_ops lp8788_rtc_ops = { |
240 | .read_time = lp8788_rtc_read_time, |
241 | .set_time = lp8788_rtc_set_time, |
242 | .read_alarm = lp8788_read_alarm, |
243 | .set_alarm = lp8788_set_alarm, |
244 | .alarm_irq_enable = lp8788_alarm_irq_enable, |
245 | }; |
246 | |
247 | static irqreturn_t lp8788_alarm_irq_handler(int irq, void *ptr) |
248 | { |
249 | struct lp8788_rtc *rtc = ptr; |
250 | |
251 | rtc_update_irq(rtc: rtc->rdev, num: 1, ALARM_IRQ_FLAG); |
252 | return IRQ_HANDLED; |
253 | } |
254 | |
255 | static int lp8788_alarm_irq_register(struct platform_device *pdev, |
256 | struct lp8788_rtc *rtc) |
257 | { |
258 | struct resource *r; |
259 | struct lp8788 *lp = rtc->lp; |
260 | struct irq_domain *irqdm = lp->irqdm; |
261 | int irq; |
262 | |
263 | rtc->irq = 0; |
264 | |
265 | /* even the alarm IRQ number is not specified, rtc time should work */ |
266 | r = platform_get_resource_byname(pdev, IORESOURCE_IRQ, LP8788_ALM_IRQ); |
267 | if (!r) |
268 | return 0; |
269 | |
270 | if (rtc->alarm == LP8788_ALARM_1) |
271 | irq = r->start; |
272 | else |
273 | irq = r->end; |
274 | |
275 | rtc->irq = irq_create_mapping(host: irqdm, hwirq: irq); |
276 | |
277 | return devm_request_threaded_irq(dev: &pdev->dev, irq: rtc->irq, NULL, |
278 | thread_fn: lp8788_alarm_irq_handler, |
279 | irqflags: 0, LP8788_ALM_IRQ, dev_id: rtc); |
280 | } |
281 | |
282 | static int lp8788_rtc_probe(struct platform_device *pdev) |
283 | { |
284 | struct lp8788 *lp = dev_get_drvdata(dev: pdev->dev.parent); |
285 | struct lp8788_rtc *rtc; |
286 | struct device *dev = &pdev->dev; |
287 | |
288 | rtc = devm_kzalloc(dev, size: sizeof(struct lp8788_rtc), GFP_KERNEL); |
289 | if (!rtc) |
290 | return -ENOMEM; |
291 | |
292 | rtc->lp = lp; |
293 | rtc->alarm = lp->pdata ? lp->pdata->alarm_sel : DEFAULT_ALARM_SEL; |
294 | platform_set_drvdata(pdev, data: rtc); |
295 | |
296 | device_init_wakeup(dev, enable: 1); |
297 | |
298 | rtc->rdev = devm_rtc_device_register(dev, name: "lp8788_rtc" , |
299 | ops: &lp8788_rtc_ops, THIS_MODULE); |
300 | if (IS_ERR(ptr: rtc->rdev)) { |
301 | dev_err(dev, "can not register rtc device\n" ); |
302 | return PTR_ERR(ptr: rtc->rdev); |
303 | } |
304 | |
305 | if (lp8788_alarm_irq_register(pdev, rtc)) |
306 | dev_warn(lp->dev, "no rtc irq handler\n" ); |
307 | |
308 | return 0; |
309 | } |
310 | |
311 | static struct platform_driver lp8788_rtc_driver = { |
312 | .probe = lp8788_rtc_probe, |
313 | .driver = { |
314 | .name = LP8788_DEV_RTC, |
315 | }, |
316 | }; |
317 | module_platform_driver(lp8788_rtc_driver); |
318 | |
319 | MODULE_DESCRIPTION("Texas Instruments LP8788 RTC Driver" ); |
320 | MODULE_AUTHOR("Milo Kim" ); |
321 | MODULE_LICENSE("GPL" ); |
322 | MODULE_ALIAS("platform:lp8788-rtc" ); |
323 | |