blob: 91ca0bc1b484b4af1120b3e1701a931a4e1ff6fc [file] [log] [blame]
Chris Zhong3ca1e322014-10-13 15:52:42 -07001/*
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
53struct rk808_rtc {
54 struct rk808 *rk808;
55 struct rtc_device *rtc;
56 int irq;
57};
58
59/* Read current time and date in RTC */
60static 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,
Chris Zhongc412c602015-02-13 14:40:54 -080070 BIT_RTC_CTRL_REG_RTC_GET_TIME);
Chris Zhong3ca1e322014-10-13 15:52:42 -070071 if (ret) {
72 dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
73 return ret;
74 }
75
Chris Zhongc412c602015-02-13 14:40:54 -080076 /*
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 */
Chris Zhong3ca1e322014-10-13 15:52:42 -070082 ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
83 BIT_RTC_CTRL_REG_RTC_GET_TIME,
Chris Zhongc412c602015-02-13 14:40:54 -080084 0);
Chris Zhong3ca1e322014-10-13 15:52:42 -070085 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 */
112static 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 */
156static 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
190static 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
201static 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
213static 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
253static 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 */
274static 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
295static 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. */
305static 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 */
319static 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
331static SIMPLE_DEV_PM_OPS(rk808_rtc_pm_ops,
332 rk808_rtc_suspend, rk808_rtc_resume);
333
334static 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
406static 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
414module_platform_driver(rk808_rtc_driver);
415
416MODULE_DESCRIPTION("RTC driver for the rk808 series PMICs");
417MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
418MODULE_AUTHOR("Zhang Qing <zhangqing@rock-chips.com>");
419MODULE_LICENSE("GPL");
420MODULE_ALIAS("platform:rk808-rtc");