drivers/rtc/rtc-da9052.c: add extra reads with timeouts to avoid returning partially...
[deliverable/linux.git] / drivers / rtc / rtc-da9052.c
CommitLineData
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1/*
2 * Real time clock driver for DA9052
3 *
4 * Copyright(c) 2012 Dialog Semiconductor Ltd.
5 *
6 * Author: Dajun Dajun Chen <dajun.chen@diasemi.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 */
14
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/rtc.h>
11f54d05 18#include <linux/err.h>
03cc1625 19#include <linux/delay.h>
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20
21#include <linux/mfd/da9052/da9052.h>
22#include <linux/mfd/da9052/reg.h>
23
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24#define rtc_err(rtc, fmt, ...) \
25 dev_err(rtc->da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__)
fef931ff 26
03cc1625
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27#define DA9052_GET_TIME_RETRIES 5
28
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29struct da9052_rtc {
30 struct rtc_device *rtc;
31 struct da9052 *da9052;
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32};
33
7c994c08 34static int da9052_rtc_enable_alarm(struct da9052_rtc *rtc, bool enable)
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35{
36 int ret;
37 if (enable) {
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38 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
39 DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON,
40 DA9052_ALARM_Y_ALARM_ON);
fef931ff 41 if (ret != 0)
7c994c08 42 rtc_err(rtc, "Failed to enable ALM: %d\n", ret);
fef931ff 43 } else {
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44 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
45 DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 0);
fef931ff 46 if (ret != 0)
7c994c08 47 rtc_err(rtc, "Write error: %d\n", ret);
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48 }
49 return ret;
50}
51
52static irqreturn_t da9052_rtc_irq(int irq, void *data)
53{
54 struct da9052_rtc *rtc = data;
fef931ff 55
7c994c08 56 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
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57
58 return IRQ_HANDLED;
59}
60
7c994c08 61static int da9052_read_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
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62{
63 int ret;
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64 uint8_t v[2][5];
65 int idx = 1;
66 int timeout = DA9052_GET_TIME_RETRIES;
fef931ff 67
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68 ret = da9052_group_read(rtc->da9052, DA9052_ALARM_MI_REG, 5, &v[0][0]);
69 if (ret) {
7c994c08 70 rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
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71 return ret;
72 }
73
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74 do {
75 ret = da9052_group_read(rtc->da9052,
76 DA9052_ALARM_MI_REG, 5, &v[idx][0]);
77 if (ret) {
78 rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
79 return ret;
80 }
fef931ff 81
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82 if (memcmp(&v[0][0], &v[1][0], 5) == 0) {
83 rtc_tm->tm_year = (v[0][4] & DA9052_RTC_YEAR) + 100;
84 rtc_tm->tm_mon = (v[0][3] & DA9052_RTC_MONTH) - 1;
85 rtc_tm->tm_mday = v[0][2] & DA9052_RTC_DAY;
86 rtc_tm->tm_hour = v[0][1] & DA9052_RTC_HOUR;
87 rtc_tm->tm_min = v[0][0] & DA9052_RTC_MIN;
88
89 ret = rtc_valid_tm(rtc_tm);
90 return ret;
91 }
92
93 idx = (1-idx);
94 msleep(20);
95
96 } while (timeout--);
97
98 rtc_err(rtc, "Timed out reading alarm time\n");
99
100 return -EIO;
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101}
102
7c994c08 103static int da9052_set_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
fef931ff 104{
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105 struct da9052 *da9052 = rtc->da9052;
106 unsigned long alm_time;
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107 int ret;
108 uint8_t v[3];
109
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110 ret = rtc_tm_to_time(rtc_tm, &alm_time);
111 if (ret != 0)
112 return ret;
113
114 if (rtc_tm->tm_sec > 0) {
115 alm_time += 60 - rtc_tm->tm_sec;
116 rtc_time_to_tm(alm_time, rtc_tm);
117 }
118 BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */
119
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120 rtc_tm->tm_year -= 100;
121 rtc_tm->tm_mon += 1;
122
123 ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG,
124 DA9052_RTC_MIN, rtc_tm->tm_min);
125 if (ret != 0) {
7c994c08 126 rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret);
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127 return ret;
128 }
129
130 v[0] = rtc_tm->tm_hour;
131 v[1] = rtc_tm->tm_mday;
132 v[2] = rtc_tm->tm_mon;
133
134 ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v);
135 if (ret < 0)
136 return ret;
137
138 ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
139 DA9052_RTC_YEAR, rtc_tm->tm_year);
140 if (ret != 0)
7c994c08 141 rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret);
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142
143 return ret;
144}
145
7c994c08 146static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc)
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147{
148 int ret;
149
7c994c08 150 ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG);
fef931ff 151 if (ret < 0) {
7c994c08 152 rtc_err(rtc, "Failed to read ALM: %d\n", ret);
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153 return ret;
154 }
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155
156 return !!(ret&DA9052_ALARM_Y_ALARM_ON);
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157}
158
159static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
160{
161 struct da9052_rtc *rtc = dev_get_drvdata(dev);
fef931ff 162 int ret;
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163 uint8_t v[2][6];
164 int idx = 1;
165 int timeout = DA9052_GET_TIME_RETRIES;
fef931ff 166
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167 ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]);
168 if (ret) {
7c994c08 169 rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
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170 return ret;
171 }
172
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173 do {
174 ret = da9052_group_read(rtc->da9052,
175 DA9052_COUNT_S_REG, 6, &v[idx][0]);
176 if (ret) {
177 rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
178 return ret;
179 }
fef931ff 180
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181 if (memcmp(&v[0][0], &v[1][0], 6) == 0) {
182 rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100;
183 rtc_tm->tm_mon = (v[0][4] & DA9052_RTC_MONTH) - 1;
184 rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY;
185 rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR;
186 rtc_tm->tm_min = v[0][1] & DA9052_RTC_MIN;
187 rtc_tm->tm_sec = v[0][0] & DA9052_RTC_SEC;
188
189 ret = rtc_valid_tm(rtc_tm);
190 return ret;
191 }
192
193 idx = (1-idx);
194 msleep(20);
195
196 } while (timeout--);
197
198 rtc_err(rtc, "Timed out reading time\n");
199
200 return -EIO;
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201}
202
203static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm)
204{
205 struct da9052_rtc *rtc;
206 uint8_t v[6];
7c994c08 207 int ret;
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208
209 rtc = dev_get_drvdata(dev);
210
211 v[0] = tm->tm_sec;
212 v[1] = tm->tm_min;
213 v[2] = tm->tm_hour;
214 v[3] = tm->tm_mday;
215 v[4] = tm->tm_mon + 1;
216 v[5] = tm->tm_year - 100;
217
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218 ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
219 if (ret < 0)
220 rtc_err(rtc, "failed to set RTC time: %d\n", ret);
221 return ret;
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222}
223
224static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
225{
226 int ret;
227 struct rtc_time *tm = &alrm->time;
228 struct da9052_rtc *rtc = dev_get_drvdata(dev);
229
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230 ret = da9052_read_alarm(rtc, tm);
231 if (ret < 0) {
232 rtc_err(rtc, "failed to read RTC alarm: %d\n", ret);
fef931ff 233 return ret;
7c994c08 234 }
fef931ff 235
7c994c08 236 alrm->enabled = da9052_rtc_get_alarm_status(rtc);
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237 return 0;
238}
239
240static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
241{
242 int ret;
243 struct rtc_time *tm = &alrm->time;
244 struct da9052_rtc *rtc = dev_get_drvdata(dev);
245
7c994c08 246 ret = da9052_rtc_enable_alarm(rtc, 0);
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247 if (ret < 0)
248 return ret;
249
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250 ret = da9052_set_alarm(rtc, tm);
251 if (ret < 0)
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252 return ret;
253
7c994c08 254 ret = da9052_rtc_enable_alarm(rtc, 1);
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255 return ret;
256}
257
258static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
259{
260 struct da9052_rtc *rtc = dev_get_drvdata(dev);
261
7c994c08 262 return da9052_rtc_enable_alarm(rtc, enabled);
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263}
264
265static const struct rtc_class_ops da9052_rtc_ops = {
266 .read_time = da9052_rtc_read_time,
267 .set_time = da9052_rtc_set_time,
268 .read_alarm = da9052_rtc_read_alarm,
269 .set_alarm = da9052_rtc_set_alarm,
270 .alarm_irq_enable = da9052_rtc_alarm_irq_enable,
271};
272
5a167f45 273static int da9052_rtc_probe(struct platform_device *pdev)
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274{
275 struct da9052_rtc *rtc;
276 int ret;
277
278 rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL);
279 if (!rtc)
280 return -ENOMEM;
281
282 rtc->da9052 = dev_get_drvdata(pdev->dev.parent);
283 platform_set_drvdata(pdev, rtc);
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284
285 ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE);
286 if (ret < 0) {
287 rtc_err(rtc,
288 "Failed to setup RTC battery charging: %d\n", ret);
289 return ret;
290 }
291
292 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
293 DA9052_ALARM_Y_TICK_ON, 0);
294 if (ret != 0)
295 rtc_err(rtc, "Failed to disable TICKS: %d\n", ret);
296
c2c0eed7 297 ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM",
925e8ea6 298 da9052_rtc_irq, rtc);
fef931ff 299 if (ret != 0) {
7c994c08 300 rtc_err(rtc, "irq registration failed: %d\n", ret);
007def04 301 return ret;
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302 }
303
3689cd74 304 rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
fef931ff 305 &da9052_rtc_ops, THIS_MODULE);
dac30a98 306 return PTR_ERR_OR_ZERO(rtc->rtc);
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307}
308
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309static struct platform_driver da9052_rtc_driver = {
310 .probe = da9052_rtc_probe,
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311 .driver = {
312 .name = "da9052-rtc",
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313 },
314};
315
316module_platform_driver(da9052_rtc_driver);
317
7c994c08 318MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
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319MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC");
320MODULE_LICENSE("GPL");
321MODULE_ALIAS("platform:da9052-rtc");
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