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3ca1e326 CZ |
1 | /* |
2 | * RTC driver for Rockchip RK808 | |
3 | * | |
4 | * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd | |
5 | * | |
6 | * Author: Chris Zhong <zyw@rock-chips.com> | |
7 | * Author: Zhang Qing <zhangqing@rock-chips.com> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify it | |
10 | * under the terms and conditions of the GNU General Public License, | |
11 | * version 2, as published by the Free Software Foundation. | |
12 | * | |
13 | * This program is distributed in the hope it will be useful, but WITHOUT | |
14 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
16 | * more details. | |
17 | */ | |
18 | ||
19 | #include <linux/module.h> | |
20 | #include <linux/kernel.h> | |
21 | #include <linux/rtc.h> | |
22 | #include <linux/bcd.h> | |
23 | #include <linux/mfd/rk808.h> | |
24 | #include <linux/platform_device.h> | |
25 | #include <linux/i2c.h> | |
26 | ||
27 | /* RTC_CTRL_REG bitfields */ | |
28 | #define BIT_RTC_CTRL_REG_STOP_RTC_M BIT(0) | |
29 | ||
30 | /* RK808 has a shadowed register for saving a "frozen" RTC time. | |
31 | * When user setting "GET_TIME" to 1, the time will save in this shadowed | |
32 | * register. If set "READSEL" to 1, user read rtc time register, actually | |
33 | * get the time of that moment. If we need the real time, clr this bit. | |
34 | */ | |
35 | #define BIT_RTC_CTRL_REG_RTC_GET_TIME BIT(6) | |
36 | #define BIT_RTC_CTRL_REG_RTC_READSEL_M BIT(7) | |
37 | #define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M BIT(3) | |
38 | #define RTC_STATUS_MASK 0xFE | |
39 | ||
40 | #define SECONDS_REG_MSK 0x7F | |
41 | #define MINUTES_REG_MAK 0x7F | |
42 | #define HOURS_REG_MSK 0x3F | |
43 | #define DAYS_REG_MSK 0x3F | |
44 | #define MONTHS_REG_MSK 0x1F | |
45 | #define YEARS_REG_MSK 0xFF | |
46 | #define WEEKS_REG_MSK 0x7 | |
47 | ||
48 | /* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */ | |
49 | ||
50 | #define NUM_TIME_REGS (RK808_WEEKS_REG - RK808_SECONDS_REG + 1) | |
51 | #define NUM_ALARM_REGS (RK808_ALARM_YEARS_REG - RK808_ALARM_SECONDS_REG + 1) | |
52 | ||
53 | struct rk808_rtc { | |
54 | struct rk808 *rk808; | |
55 | struct rtc_device *rtc; | |
56 | int irq; | |
57 | }; | |
58 | ||
59 | /* Read current time and date in RTC */ | |
60 | static int rk808_rtc_readtime(struct device *dev, struct rtc_time *tm) | |
61 | { | |
62 | struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev); | |
63 | struct rk808 *rk808 = rk808_rtc->rk808; | |
64 | u8 rtc_data[NUM_TIME_REGS]; | |
65 | int ret; | |
66 | ||
67 | /* Force an update of the shadowed registers right now */ | |
68 | ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG, | |
69 | BIT_RTC_CTRL_REG_RTC_GET_TIME, | |
c412c603 | 70 | BIT_RTC_CTRL_REG_RTC_GET_TIME); |
3ca1e326 CZ |
71 | if (ret) { |
72 | dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret); | |
73 | return ret; | |
74 | } | |
75 | ||
c412c603 CZ |
76 | /* |
77 | * After we set the GET_TIME bit, the rtc time can't be read | |
78 | * immediately. So we should wait up to 31.25 us, about one cycle of | |
79 | * 32khz. If we clear the GET_TIME bit here, the time of i2c transfer | |
80 | * certainly more than 31.25us: 16 * 2.5us at 400kHz bus frequency. | |
81 | */ | |
3ca1e326 CZ |
82 | ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG, |
83 | BIT_RTC_CTRL_REG_RTC_GET_TIME, | |
c412c603 | 84 | 0); |
3ca1e326 CZ |
85 | if (ret) { |
86 | dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret); | |
87 | return ret; | |
88 | } | |
89 | ||
90 | ret = regmap_bulk_read(rk808->regmap, RK808_SECONDS_REG, | |
91 | rtc_data, NUM_TIME_REGS); | |
92 | if (ret) { | |
93 | dev_err(dev, "Failed to bulk read rtc_data: %d\n", ret); | |
94 | return ret; | |
95 | } | |
96 | ||
97 | tm->tm_sec = bcd2bin(rtc_data[0] & SECONDS_REG_MSK); | |
98 | tm->tm_min = bcd2bin(rtc_data[1] & MINUTES_REG_MAK); | |
99 | tm->tm_hour = bcd2bin(rtc_data[2] & HOURS_REG_MSK); | |
100 | tm->tm_mday = bcd2bin(rtc_data[3] & DAYS_REG_MSK); | |
101 | tm->tm_mon = (bcd2bin(rtc_data[4] & MONTHS_REG_MSK)) - 1; | |
102 | tm->tm_year = (bcd2bin(rtc_data[5] & YEARS_REG_MSK)) + 100; | |
103 | tm->tm_wday = bcd2bin(rtc_data[6] & WEEKS_REG_MSK); | |
104 | dev_dbg(dev, "RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n", | |
105 | 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday, | |
106 | tm->tm_wday, tm->tm_hour , tm->tm_min, tm->tm_sec); | |
107 | ||
108 | return ret; | |
109 | } | |
110 | ||
111 | /* Set current time and date in RTC */ | |
112 | static int rk808_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
113 | { | |
114 | struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev); | |
115 | struct rk808 *rk808 = rk808_rtc->rk808; | |
116 | u8 rtc_data[NUM_TIME_REGS]; | |
117 | int ret; | |
118 | ||
119 | rtc_data[0] = bin2bcd(tm->tm_sec); | |
120 | rtc_data[1] = bin2bcd(tm->tm_min); | |
121 | rtc_data[2] = bin2bcd(tm->tm_hour); | |
122 | rtc_data[3] = bin2bcd(tm->tm_mday); | |
123 | rtc_data[4] = bin2bcd(tm->tm_mon + 1); | |
124 | rtc_data[5] = bin2bcd(tm->tm_year - 100); | |
125 | rtc_data[6] = bin2bcd(tm->tm_wday); | |
126 | dev_dbg(dev, "set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n", | |
127 | 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday, | |
128 | tm->tm_wday, tm->tm_hour , tm->tm_min, tm->tm_sec); | |
129 | ||
130 | /* Stop RTC while updating the RTC registers */ | |
131 | ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG, | |
132 | BIT_RTC_CTRL_REG_STOP_RTC_M, | |
133 | BIT_RTC_CTRL_REG_STOP_RTC_M); | |
134 | if (ret) { | |
135 | dev_err(dev, "Failed to update RTC control: %d\n", ret); | |
136 | return ret; | |
137 | } | |
138 | ||
139 | ret = regmap_bulk_write(rk808->regmap, RK808_SECONDS_REG, | |
140 | rtc_data, NUM_TIME_REGS); | |
141 | if (ret) { | |
142 | dev_err(dev, "Failed to bull write rtc_data: %d\n", ret); | |
143 | return ret; | |
144 | } | |
145 | /* Start RTC again */ | |
146 | ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG, | |
147 | BIT_RTC_CTRL_REG_STOP_RTC_M, 0); | |
148 | if (ret) { | |
149 | dev_err(dev, "Failed to update RTC control: %d\n", ret); | |
150 | return ret; | |
151 | } | |
152 | return 0; | |
153 | } | |
154 | ||
155 | /* Read alarm time and date in RTC */ | |
156 | static int rk808_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) | |
157 | { | |
158 | struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev); | |
159 | struct rk808 *rk808 = rk808_rtc->rk808; | |
160 | u8 alrm_data[NUM_ALARM_REGS]; | |
161 | uint32_t int_reg; | |
162 | int ret; | |
163 | ||
164 | ret = regmap_bulk_read(rk808->regmap, RK808_ALARM_SECONDS_REG, | |
165 | alrm_data, NUM_ALARM_REGS); | |
166 | ||
167 | alrm->time.tm_sec = bcd2bin(alrm_data[0] & SECONDS_REG_MSK); | |
168 | alrm->time.tm_min = bcd2bin(alrm_data[1] & MINUTES_REG_MAK); | |
169 | alrm->time.tm_hour = bcd2bin(alrm_data[2] & HOURS_REG_MSK); | |
170 | alrm->time.tm_mday = bcd2bin(alrm_data[3] & DAYS_REG_MSK); | |
171 | alrm->time.tm_mon = (bcd2bin(alrm_data[4] & MONTHS_REG_MSK)) - 1; | |
172 | alrm->time.tm_year = (bcd2bin(alrm_data[5] & YEARS_REG_MSK)) + 100; | |
173 | ||
174 | ret = regmap_read(rk808->regmap, RK808_RTC_INT_REG, &int_reg); | |
175 | if (ret) { | |
176 | dev_err(dev, "Failed to read RTC INT REG: %d\n", ret); | |
177 | return ret; | |
178 | } | |
179 | ||
180 | dev_dbg(dev, "alrm read RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n", | |
181 | 1900 + alrm->time.tm_year, alrm->time.tm_mon + 1, | |
182 | alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour, | |
183 | alrm->time.tm_min, alrm->time.tm_sec); | |
184 | ||
185 | alrm->enabled = (int_reg & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M) ? 1 : 0; | |
186 | ||
187 | return 0; | |
188 | } | |
189 | ||
190 | static int rk808_rtc_stop_alarm(struct rk808_rtc *rk808_rtc) | |
191 | { | |
192 | struct rk808 *rk808 = rk808_rtc->rk808; | |
193 | int ret; | |
194 | ||
195 | ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG, | |
196 | BIT_RTC_INTERRUPTS_REG_IT_ALARM_M, 0); | |
197 | ||
198 | return ret; | |
199 | } | |
200 | ||
201 | static int rk808_rtc_start_alarm(struct rk808_rtc *rk808_rtc) | |
202 | { | |
203 | struct rk808 *rk808 = rk808_rtc->rk808; | |
204 | int ret; | |
205 | ||
206 | ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG, | |
207 | BIT_RTC_INTERRUPTS_REG_IT_ALARM_M, | |
208 | BIT_RTC_INTERRUPTS_REG_IT_ALARM_M); | |
209 | ||
210 | return ret; | |
211 | } | |
212 | ||
213 | static int rk808_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) | |
214 | { | |
215 | struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev); | |
216 | struct rk808 *rk808 = rk808_rtc->rk808; | |
217 | u8 alrm_data[NUM_ALARM_REGS]; | |
218 | int ret; | |
219 | ||
220 | ret = rk808_rtc_stop_alarm(rk808_rtc); | |
221 | if (ret) { | |
222 | dev_err(dev, "Failed to stop alarm: %d\n", ret); | |
223 | return ret; | |
224 | } | |
225 | dev_dbg(dev, "alrm set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n", | |
226 | 1900 + alrm->time.tm_year, alrm->time.tm_mon + 1, | |
227 | alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour, | |
228 | alrm->time.tm_min, alrm->time.tm_sec); | |
229 | ||
230 | alrm_data[0] = bin2bcd(alrm->time.tm_sec); | |
231 | alrm_data[1] = bin2bcd(alrm->time.tm_min); | |
232 | alrm_data[2] = bin2bcd(alrm->time.tm_hour); | |
233 | alrm_data[3] = bin2bcd(alrm->time.tm_mday); | |
234 | alrm_data[4] = bin2bcd(alrm->time.tm_mon + 1); | |
235 | alrm_data[5] = bin2bcd(alrm->time.tm_year - 100); | |
236 | ||
237 | ret = regmap_bulk_write(rk808->regmap, RK808_ALARM_SECONDS_REG, | |
238 | alrm_data, NUM_ALARM_REGS); | |
239 | if (ret) { | |
240 | dev_err(dev, "Failed to bulk write: %d\n", ret); | |
241 | return ret; | |
242 | } | |
243 | if (alrm->enabled) { | |
244 | ret = rk808_rtc_start_alarm(rk808_rtc); | |
245 | if (ret) { | |
246 | dev_err(dev, "Failed to start alarm: %d\n", ret); | |
247 | return ret; | |
248 | } | |
249 | } | |
250 | return 0; | |
251 | } | |
252 | ||
253 | static int rk808_rtc_alarm_irq_enable(struct device *dev, | |
254 | unsigned int enabled) | |
255 | { | |
256 | struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev); | |
257 | ||
258 | if (enabled) | |
259 | return rk808_rtc_start_alarm(rk808_rtc); | |
260 | ||
261 | return rk808_rtc_stop_alarm(rk808_rtc); | |
262 | } | |
263 | ||
264 | /* | |
265 | * We will just handle setting the frequency and make use the framework for | |
266 | * reading the periodic interupts. | |
267 | * | |
268 | * @freq: Current periodic IRQ freq: | |
269 | * bit 0: every second | |
270 | * bit 1: every minute | |
271 | * bit 2: every hour | |
272 | * bit 3: every day | |
273 | */ | |
274 | static irqreturn_t rk808_alarm_irq(int irq, void *data) | |
275 | { | |
276 | struct rk808_rtc *rk808_rtc = data; | |
277 | struct rk808 *rk808 = rk808_rtc->rk808; | |
278 | struct i2c_client *client = rk808->i2c; | |
279 | int ret; | |
280 | ||
281 | ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG, | |
282 | RTC_STATUS_MASK); | |
283 | if (ret) { | |
284 | dev_err(&client->dev, | |
285 | "%s:Failed to update RTC status: %d\n", __func__, ret); | |
286 | return ret; | |
287 | } | |
288 | ||
289 | rtc_update_irq(rk808_rtc->rtc, 1, RTC_IRQF | RTC_AF); | |
290 | dev_dbg(&client->dev, | |
291 | "%s:irq=%d\n", __func__, irq); | |
292 | return IRQ_HANDLED; | |
293 | } | |
294 | ||
295 | static const struct rtc_class_ops rk808_rtc_ops = { | |
296 | .read_time = rk808_rtc_readtime, | |
297 | .set_time = rk808_rtc_set_time, | |
298 | .read_alarm = rk808_rtc_readalarm, | |
299 | .set_alarm = rk808_rtc_setalarm, | |
300 | .alarm_irq_enable = rk808_rtc_alarm_irq_enable, | |
301 | }; | |
302 | ||
303 | #ifdef CONFIG_PM_SLEEP | |
304 | /* Turn off the alarm if it should not be a wake source. */ | |
305 | static int rk808_rtc_suspend(struct device *dev) | |
306 | { | |
307 | struct platform_device *pdev = to_platform_device(dev); | |
308 | struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev); | |
309 | ||
310 | if (device_may_wakeup(dev)) | |
311 | enable_irq_wake(rk808_rtc->irq); | |
312 | ||
313 | return 0; | |
314 | } | |
315 | ||
316 | /* Enable the alarm if it should be enabled (in case it was disabled to | |
317 | * prevent use as a wake source). | |
318 | */ | |
319 | static int rk808_rtc_resume(struct device *dev) | |
320 | { | |
321 | struct platform_device *pdev = to_platform_device(dev); | |
322 | struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev); | |
323 | ||
324 | if (device_may_wakeup(dev)) | |
325 | disable_irq_wake(rk808_rtc->irq); | |
326 | ||
327 | return 0; | |
328 | } | |
329 | #endif | |
330 | ||
331 | static SIMPLE_DEV_PM_OPS(rk808_rtc_pm_ops, | |
332 | rk808_rtc_suspend, rk808_rtc_resume); | |
333 | ||
334 | static int rk808_rtc_probe(struct platform_device *pdev) | |
335 | { | |
336 | struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent); | |
337 | struct rk808_rtc *rk808_rtc; | |
338 | struct rtc_time tm; | |
339 | int ret; | |
340 | ||
341 | rk808_rtc = devm_kzalloc(&pdev->dev, sizeof(*rk808_rtc), GFP_KERNEL); | |
342 | if (rk808_rtc == NULL) | |
343 | return -ENOMEM; | |
344 | ||
345 | platform_set_drvdata(pdev, rk808_rtc); | |
346 | rk808_rtc->rk808 = rk808; | |
347 | ||
348 | /* start rtc running by default, and use shadowed timer. */ | |
349 | ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG, | |
350 | BIT_RTC_CTRL_REG_STOP_RTC_M | | |
351 | BIT_RTC_CTRL_REG_RTC_READSEL_M, | |
352 | BIT_RTC_CTRL_REG_RTC_READSEL_M); | |
353 | if (ret) { | |
354 | dev_err(&pdev->dev, | |
355 | "Failed to update RTC control: %d\n", ret); | |
356 | return ret; | |
357 | } | |
358 | ||
359 | ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG, | |
360 | RTC_STATUS_MASK); | |
361 | if (ret) { | |
362 | dev_err(&pdev->dev, | |
363 | "Failed to write RTC status: %d\n", ret); | |
364 | return ret; | |
365 | } | |
366 | ||
367 | /* set init time */ | |
368 | ret = rk808_rtc_readtime(&pdev->dev, &tm); | |
369 | if (ret) { | |
370 | dev_err(&pdev->dev, "Failed to read RTC time\n"); | |
371 | return ret; | |
372 | } | |
373 | ret = rtc_valid_tm(&tm); | |
374 | if (ret) | |
375 | dev_warn(&pdev->dev, "invalid date/time\n"); | |
376 | ||
377 | device_init_wakeup(&pdev->dev, 1); | |
378 | ||
379 | rk808_rtc->rtc = devm_rtc_device_register(&pdev->dev, "rk808-rtc", | |
380 | &rk808_rtc_ops, THIS_MODULE); | |
381 | if (IS_ERR(rk808_rtc->rtc)) { | |
382 | ret = PTR_ERR(rk808_rtc->rtc); | |
383 | return ret; | |
384 | } | |
385 | ||
386 | rk808_rtc->irq = platform_get_irq(pdev, 0); | |
387 | if (rk808_rtc->irq < 0) { | |
388 | if (rk808_rtc->irq != -EPROBE_DEFER) | |
389 | dev_err(&pdev->dev, "Wake up is not possible as irq = %d\n", | |
390 | rk808_rtc->irq); | |
391 | return rk808_rtc->irq; | |
392 | } | |
393 | ||
394 | /* request alarm irq of rk808 */ | |
395 | ret = devm_request_threaded_irq(&pdev->dev, rk808_rtc->irq, NULL, | |
396 | rk808_alarm_irq, 0, | |
397 | "RTC alarm", rk808_rtc); | |
398 | if (ret) { | |
399 | dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n", | |
400 | rk808_rtc->irq, ret); | |
401 | } | |
402 | ||
403 | return ret; | |
404 | } | |
405 | ||
406 | static struct platform_driver rk808_rtc_driver = { | |
407 | .probe = rk808_rtc_probe, | |
408 | .driver = { | |
409 | .name = "rk808-rtc", | |
410 | .pm = &rk808_rtc_pm_ops, | |
411 | }, | |
412 | }; | |
413 | ||
414 | module_platform_driver(rk808_rtc_driver); | |
415 | ||
416 | MODULE_DESCRIPTION("RTC driver for the rk808 series PMICs"); | |
417 | MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>"); | |
418 | MODULE_AUTHOR("Zhang Qing <zhangqing@rock-chips.com>"); | |
419 | MODULE_LICENSE("GPL"); | |
420 | MODULE_ALIAS("platform:rk808-rtc"); |