blob: df42257668acedb18efce482294821499ed31685 [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,
70 0);
71 if (ret) {
72 dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
73 return ret;
74 }
75
76 ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
77 BIT_RTC_CTRL_REG_RTC_GET_TIME,
78 BIT_RTC_CTRL_REG_RTC_GET_TIME);
79 if (ret) {
80 dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
81 return ret;
82 }
83
84 ret = regmap_bulk_read(rk808->regmap, RK808_SECONDS_REG,
85 rtc_data, NUM_TIME_REGS);
86 if (ret) {
87 dev_err(dev, "Failed to bulk read rtc_data: %d\n", ret);
88 return ret;
89 }
90
91 tm->tm_sec = bcd2bin(rtc_data[0] & SECONDS_REG_MSK);
92 tm->tm_min = bcd2bin(rtc_data[1] & MINUTES_REG_MAK);
93 tm->tm_hour = bcd2bin(rtc_data[2] & HOURS_REG_MSK);
94 tm->tm_mday = bcd2bin(rtc_data[3] & DAYS_REG_MSK);
95 tm->tm_mon = (bcd2bin(rtc_data[4] & MONTHS_REG_MSK)) - 1;
96 tm->tm_year = (bcd2bin(rtc_data[5] & YEARS_REG_MSK)) + 100;
97 tm->tm_wday = bcd2bin(rtc_data[6] & WEEKS_REG_MSK);
98 dev_dbg(dev, "RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
99 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
100 tm->tm_wday, tm->tm_hour , tm->tm_min, tm->tm_sec);
101
102 return ret;
103}
104
105/* Set current time and date in RTC */
106static int rk808_rtc_set_time(struct device *dev, struct rtc_time *tm)
107{
108 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
109 struct rk808 *rk808 = rk808_rtc->rk808;
110 u8 rtc_data[NUM_TIME_REGS];
111 int ret;
112
113 rtc_data[0] = bin2bcd(tm->tm_sec);
114 rtc_data[1] = bin2bcd(tm->tm_min);
115 rtc_data[2] = bin2bcd(tm->tm_hour);
116 rtc_data[3] = bin2bcd(tm->tm_mday);
117 rtc_data[4] = bin2bcd(tm->tm_mon + 1);
118 rtc_data[5] = bin2bcd(tm->tm_year - 100);
119 rtc_data[6] = bin2bcd(tm->tm_wday);
120 dev_dbg(dev, "set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
121 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
122 tm->tm_wday, tm->tm_hour , tm->tm_min, tm->tm_sec);
123
124 /* Stop RTC while updating the RTC registers */
125 ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
126 BIT_RTC_CTRL_REG_STOP_RTC_M,
127 BIT_RTC_CTRL_REG_STOP_RTC_M);
128 if (ret) {
129 dev_err(dev, "Failed to update RTC control: %d\n", ret);
130 return ret;
131 }
132
133 ret = regmap_bulk_write(rk808->regmap, RK808_SECONDS_REG,
134 rtc_data, NUM_TIME_REGS);
135 if (ret) {
136 dev_err(dev, "Failed to bull write rtc_data: %d\n", ret);
137 return ret;
138 }
139 /* Start RTC again */
140 ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
141 BIT_RTC_CTRL_REG_STOP_RTC_M, 0);
142 if (ret) {
143 dev_err(dev, "Failed to update RTC control: %d\n", ret);
144 return ret;
145 }
146 return 0;
147}
148
149/* Read alarm time and date in RTC */
150static int rk808_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
151{
152 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
153 struct rk808 *rk808 = rk808_rtc->rk808;
154 u8 alrm_data[NUM_ALARM_REGS];
155 uint32_t int_reg;
156 int ret;
157
158 ret = regmap_bulk_read(rk808->regmap, RK808_ALARM_SECONDS_REG,
159 alrm_data, NUM_ALARM_REGS);
160
161 alrm->time.tm_sec = bcd2bin(alrm_data[0] & SECONDS_REG_MSK);
162 alrm->time.tm_min = bcd2bin(alrm_data[1] & MINUTES_REG_MAK);
163 alrm->time.tm_hour = bcd2bin(alrm_data[2] & HOURS_REG_MSK);
164 alrm->time.tm_mday = bcd2bin(alrm_data[3] & DAYS_REG_MSK);
165 alrm->time.tm_mon = (bcd2bin(alrm_data[4] & MONTHS_REG_MSK)) - 1;
166 alrm->time.tm_year = (bcd2bin(alrm_data[5] & YEARS_REG_MSK)) + 100;
167
168 ret = regmap_read(rk808->regmap, RK808_RTC_INT_REG, &int_reg);
169 if (ret) {
170 dev_err(dev, "Failed to read RTC INT REG: %d\n", ret);
171 return ret;
172 }
173
174 dev_dbg(dev, "alrm read RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
175 1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
176 alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
177 alrm->time.tm_min, alrm->time.tm_sec);
178
179 alrm->enabled = (int_reg & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M) ? 1 : 0;
180
181 return 0;
182}
183
184static int rk808_rtc_stop_alarm(struct rk808_rtc *rk808_rtc)
185{
186 struct rk808 *rk808 = rk808_rtc->rk808;
187 int ret;
188
189 ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG,
190 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M, 0);
191
192 return ret;
193}
194
195static int rk808_rtc_start_alarm(struct rk808_rtc *rk808_rtc)
196{
197 struct rk808 *rk808 = rk808_rtc->rk808;
198 int ret;
199
200 ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG,
201 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M,
202 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
203
204 return ret;
205}
206
207static int rk808_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
208{
209 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
210 struct rk808 *rk808 = rk808_rtc->rk808;
211 u8 alrm_data[NUM_ALARM_REGS];
212 int ret;
213
214 ret = rk808_rtc_stop_alarm(rk808_rtc);
215 if (ret) {
216 dev_err(dev, "Failed to stop alarm: %d\n", ret);
217 return ret;
218 }
219 dev_dbg(dev, "alrm set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
220 1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
221 alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
222 alrm->time.tm_min, alrm->time.tm_sec);
223
224 alrm_data[0] = bin2bcd(alrm->time.tm_sec);
225 alrm_data[1] = bin2bcd(alrm->time.tm_min);
226 alrm_data[2] = bin2bcd(alrm->time.tm_hour);
227 alrm_data[3] = bin2bcd(alrm->time.tm_mday);
228 alrm_data[4] = bin2bcd(alrm->time.tm_mon + 1);
229 alrm_data[5] = bin2bcd(alrm->time.tm_year - 100);
230
231 ret = regmap_bulk_write(rk808->regmap, RK808_ALARM_SECONDS_REG,
232 alrm_data, NUM_ALARM_REGS);
233 if (ret) {
234 dev_err(dev, "Failed to bulk write: %d\n", ret);
235 return ret;
236 }
237 if (alrm->enabled) {
238 ret = rk808_rtc_start_alarm(rk808_rtc);
239 if (ret) {
240 dev_err(dev, "Failed to start alarm: %d\n", ret);
241 return ret;
242 }
243 }
244 return 0;
245}
246
247static int rk808_rtc_alarm_irq_enable(struct device *dev,
248 unsigned int enabled)
249{
250 struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
251
252 if (enabled)
253 return rk808_rtc_start_alarm(rk808_rtc);
254
255 return rk808_rtc_stop_alarm(rk808_rtc);
256}
257
258/*
259 * We will just handle setting the frequency and make use the framework for
260 * reading the periodic interupts.
261 *
262 * @freq: Current periodic IRQ freq:
263 * bit 0: every second
264 * bit 1: every minute
265 * bit 2: every hour
266 * bit 3: every day
267 */
268static irqreturn_t rk808_alarm_irq(int irq, void *data)
269{
270 struct rk808_rtc *rk808_rtc = data;
271 struct rk808 *rk808 = rk808_rtc->rk808;
272 struct i2c_client *client = rk808->i2c;
273 int ret;
274
275 ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG,
276 RTC_STATUS_MASK);
277 if (ret) {
278 dev_err(&client->dev,
279 "%s:Failed to update RTC status: %d\n", __func__, ret);
280 return ret;
281 }
282
283 rtc_update_irq(rk808_rtc->rtc, 1, RTC_IRQF | RTC_AF);
284 dev_dbg(&client->dev,
285 "%s:irq=%d\n", __func__, irq);
286 return IRQ_HANDLED;
287}
288
289static const struct rtc_class_ops rk808_rtc_ops = {
290 .read_time = rk808_rtc_readtime,
291 .set_time = rk808_rtc_set_time,
292 .read_alarm = rk808_rtc_readalarm,
293 .set_alarm = rk808_rtc_setalarm,
294 .alarm_irq_enable = rk808_rtc_alarm_irq_enable,
295};
296
297#ifdef CONFIG_PM_SLEEP
298/* Turn off the alarm if it should not be a wake source. */
299static int rk808_rtc_suspend(struct device *dev)
300{
301 struct platform_device *pdev = to_platform_device(dev);
302 struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev);
303
304 if (device_may_wakeup(dev))
305 enable_irq_wake(rk808_rtc->irq);
306
307 return 0;
308}
309
310/* Enable the alarm if it should be enabled (in case it was disabled to
311 * prevent use as a wake source).
312 */
313static int rk808_rtc_resume(struct device *dev)
314{
315 struct platform_device *pdev = to_platform_device(dev);
316 struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev);
317
318 if (device_may_wakeup(dev))
319 disable_irq_wake(rk808_rtc->irq);
320
321 return 0;
322}
323#endif
324
325static SIMPLE_DEV_PM_OPS(rk808_rtc_pm_ops,
326 rk808_rtc_suspend, rk808_rtc_resume);
327
328static int rk808_rtc_probe(struct platform_device *pdev)
329{
330 struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
331 struct rk808_rtc *rk808_rtc;
332 struct rtc_time tm;
333 int ret;
334
335 rk808_rtc = devm_kzalloc(&pdev->dev, sizeof(*rk808_rtc), GFP_KERNEL);
336 if (rk808_rtc == NULL)
337 return -ENOMEM;
338
339 platform_set_drvdata(pdev, rk808_rtc);
340 rk808_rtc->rk808 = rk808;
341
342 /* start rtc running by default, and use shadowed timer. */
343 ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
344 BIT_RTC_CTRL_REG_STOP_RTC_M |
345 BIT_RTC_CTRL_REG_RTC_READSEL_M,
346 BIT_RTC_CTRL_REG_RTC_READSEL_M);
347 if (ret) {
348 dev_err(&pdev->dev,
349 "Failed to update RTC control: %d\n", ret);
350 return ret;
351 }
352
353 ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG,
354 RTC_STATUS_MASK);
355 if (ret) {
356 dev_err(&pdev->dev,
357 "Failed to write RTC status: %d\n", ret);
358 return ret;
359 }
360
361 /* set init time */
362 ret = rk808_rtc_readtime(&pdev->dev, &tm);
363 if (ret) {
364 dev_err(&pdev->dev, "Failed to read RTC time\n");
365 return ret;
366 }
367 ret = rtc_valid_tm(&tm);
368 if (ret)
369 dev_warn(&pdev->dev, "invalid date/time\n");
370
371 device_init_wakeup(&pdev->dev, 1);
372
373 rk808_rtc->rtc = devm_rtc_device_register(&pdev->dev, "rk808-rtc",
374 &rk808_rtc_ops, THIS_MODULE);
375 if (IS_ERR(rk808_rtc->rtc)) {
376 ret = PTR_ERR(rk808_rtc->rtc);
377 return ret;
378 }
379
380 rk808_rtc->irq = platform_get_irq(pdev, 0);
381 if (rk808_rtc->irq < 0) {
382 if (rk808_rtc->irq != -EPROBE_DEFER)
383 dev_err(&pdev->dev, "Wake up is not possible as irq = %d\n",
384 rk808_rtc->irq);
385 return rk808_rtc->irq;
386 }
387
388 /* request alarm irq of rk808 */
389 ret = devm_request_threaded_irq(&pdev->dev, rk808_rtc->irq, NULL,
390 rk808_alarm_irq, 0,
391 "RTC alarm", rk808_rtc);
392 if (ret) {
393 dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
394 rk808_rtc->irq, ret);
395 }
396
397 return ret;
398}
399
400static struct platform_driver rk808_rtc_driver = {
401 .probe = rk808_rtc_probe,
402 .driver = {
403 .name = "rk808-rtc",
404 .pm = &rk808_rtc_pm_ops,
405 },
406};
407
408module_platform_driver(rk808_rtc_driver);
409
410MODULE_DESCRIPTION("RTC driver for the rk808 series PMICs");
411MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
412MODULE_AUTHOR("Zhang Qing <zhangqing@rock-chips.com>");
413MODULE_LICENSE("GPL");
414MODULE_ALIAS("platform:rk808-rtc");