1 /*
2 * rtc-palmas.c -- Palmas Real Time Clock driver.
3
4 * RTC driver for TI Palma series devices like TPS65913,
5 * TPS65914 power management IC.
6 *
7 * Copyright (c) 2012, NVIDIA Corporation.
8 *
9 * Author: Laxman Dewangan <ldewangan@nvidia.com>
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation version 2.
14 *
15 * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
16 * whether express or implied; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
23 * 02111-1307, USA
24 */
25
26 #include <linux/bcd.h>
27 #include <linux/errno.h>
28 #include <linux/init.h>
29 #include <linux/interrupt.h>
30 #include <linux/kernel.h>
31 #include <linux/mfd/palmas.h>
32 #include <linux/module.h>
33 #include <linux/of.h>
34 #include <linux/rtc.h>
35 #include <linux/types.h>
36 #include <linux/platform_device.h>
37 #include <linux/pm.h>
38
39 struct palmas_rtc {
40 struct rtc_device *rtc;
41 struct device *dev;
42 unsigned int irq;
43 };
44
45 /* Total number of RTC registers needed to set time*/
46 #define PALMAS_NUM_TIME_REGS (PALMAS_YEARS_REG - PALMAS_SECONDS_REG + 1)
47
palmas_rtc_read_time(struct device * dev,struct rtc_time * tm)48 static int palmas_rtc_read_time(struct device *dev, struct rtc_time *tm)
49 {
50 unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
51 struct palmas *palmas = dev_get_drvdata(dev->parent);
52 int ret;
53
54 /* Copy RTC counting registers to static registers or latches */
55 ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
56 PALMAS_RTC_CTRL_REG_GET_TIME, PALMAS_RTC_CTRL_REG_GET_TIME);
57 if (ret < 0) {
58 dev_err(dev, "RTC CTRL reg update failed, err: %d\n", ret);
59 return ret;
60 }
61
62 ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
63 rtc_data, PALMAS_NUM_TIME_REGS);
64 if (ret < 0) {
65 dev_err(dev, "RTC_SECONDS reg read failed, err = %d\n", ret);
66 return ret;
67 }
68
69 tm->tm_sec = bcd2bin(rtc_data[0]);
70 tm->tm_min = bcd2bin(rtc_data[1]);
71 tm->tm_hour = bcd2bin(rtc_data[2]);
72 tm->tm_mday = bcd2bin(rtc_data[3]);
73 tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
74 tm->tm_year = bcd2bin(rtc_data[5]) + 100;
75
76 return ret;
77 }
78
palmas_rtc_set_time(struct device * dev,struct rtc_time * tm)79 static int palmas_rtc_set_time(struct device *dev, struct rtc_time *tm)
80 {
81 unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
82 struct palmas *palmas = dev_get_drvdata(dev->parent);
83 int ret;
84
85 rtc_data[0] = bin2bcd(tm->tm_sec);
86 rtc_data[1] = bin2bcd(tm->tm_min);
87 rtc_data[2] = bin2bcd(tm->tm_hour);
88 rtc_data[3] = bin2bcd(tm->tm_mday);
89 rtc_data[4] = bin2bcd(tm->tm_mon + 1);
90 rtc_data[5] = bin2bcd(tm->tm_year - 100);
91
92 /* Stop RTC while updating the RTC time registers */
93 ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
94 PALMAS_RTC_CTRL_REG_STOP_RTC, 0);
95 if (ret < 0) {
96 dev_err(dev, "RTC stop failed, err = %d\n", ret);
97 return ret;
98 }
99
100 ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
101 rtc_data, PALMAS_NUM_TIME_REGS);
102 if (ret < 0) {
103 dev_err(dev, "RTC_SECONDS reg write failed, err = %d\n", ret);
104 return ret;
105 }
106
107 /* Start back RTC */
108 ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
109 PALMAS_RTC_CTRL_REG_STOP_RTC, PALMAS_RTC_CTRL_REG_STOP_RTC);
110 if (ret < 0)
111 dev_err(dev, "RTC start failed, err = %d\n", ret);
112 return ret;
113 }
114
palmas_rtc_alarm_irq_enable(struct device * dev,unsigned enabled)115 static int palmas_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
116 {
117 struct palmas *palmas = dev_get_drvdata(dev->parent);
118 u8 val;
119
120 val = enabled ? PALMAS_RTC_INTERRUPTS_REG_IT_ALARM : 0;
121 return palmas_write(palmas, PALMAS_RTC_BASE,
122 PALMAS_RTC_INTERRUPTS_REG, val);
123 }
124
palmas_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alm)125 static int palmas_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
126 {
127 unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
128 u32 int_val;
129 struct palmas *palmas = dev_get_drvdata(dev->parent);
130 int ret;
131
132 ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE,
133 PALMAS_ALARM_SECONDS_REG,
134 alarm_data, PALMAS_NUM_TIME_REGS);
135 if (ret < 0) {
136 dev_err(dev, "RTC_ALARM_SECONDS read failed, err = %d\n", ret);
137 return ret;
138 }
139
140 alm->time.tm_sec = bcd2bin(alarm_data[0]);
141 alm->time.tm_min = bcd2bin(alarm_data[1]);
142 alm->time.tm_hour = bcd2bin(alarm_data[2]);
143 alm->time.tm_mday = bcd2bin(alarm_data[3]);
144 alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
145 alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
146
147 ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_INTERRUPTS_REG,
148 &int_val);
149 if (ret < 0) {
150 dev_err(dev, "RTC_INTERRUPTS reg read failed, err = %d\n", ret);
151 return ret;
152 }
153
154 if (int_val & PALMAS_RTC_INTERRUPTS_REG_IT_ALARM)
155 alm->enabled = 1;
156 return ret;
157 }
158
palmas_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alm)159 static int palmas_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
160 {
161 unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
162 struct palmas *palmas = dev_get_drvdata(dev->parent);
163 int ret;
164
165 ret = palmas_rtc_alarm_irq_enable(dev, 0);
166 if (ret < 0) {
167 dev_err(dev, "Disable RTC alarm failed\n");
168 return ret;
169 }
170
171 alarm_data[0] = bin2bcd(alm->time.tm_sec);
172 alarm_data[1] = bin2bcd(alm->time.tm_min);
173 alarm_data[2] = bin2bcd(alm->time.tm_hour);
174 alarm_data[3] = bin2bcd(alm->time.tm_mday);
175 alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
176 alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
177
178 ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE,
179 PALMAS_ALARM_SECONDS_REG, alarm_data, PALMAS_NUM_TIME_REGS);
180 if (ret < 0) {
181 dev_err(dev, "ALARM_SECONDS_REG write failed, err = %d\n", ret);
182 return ret;
183 }
184
185 if (alm->enabled)
186 ret = palmas_rtc_alarm_irq_enable(dev, 1);
187 return ret;
188 }
189
palmas_clear_interrupts(struct device * dev)190 static int palmas_clear_interrupts(struct device *dev)
191 {
192 struct palmas *palmas = dev_get_drvdata(dev->parent);
193 unsigned int rtc_reg;
194 int ret;
195
196 ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
197 &rtc_reg);
198 if (ret < 0) {
199 dev_err(dev, "RTC_STATUS read failed, err = %d\n", ret);
200 return ret;
201 }
202
203 ret = palmas_write(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
204 rtc_reg);
205 if (ret < 0) {
206 dev_err(dev, "RTC_STATUS write failed, err = %d\n", ret);
207 return ret;
208 }
209 return 0;
210 }
211
palmas_rtc_interrupt(int irq,void * context)212 static irqreturn_t palmas_rtc_interrupt(int irq, void *context)
213 {
214 struct palmas_rtc *palmas_rtc = context;
215 struct device *dev = palmas_rtc->dev;
216 int ret;
217
218 ret = palmas_clear_interrupts(dev);
219 if (ret < 0) {
220 dev_err(dev, "RTC interrupt clear failed, err = %d\n", ret);
221 return IRQ_NONE;
222 }
223
224 rtc_update_irq(palmas_rtc->rtc, 1, RTC_IRQF | RTC_AF);
225 return IRQ_HANDLED;
226 }
227
228 static const struct rtc_class_ops palmas_rtc_ops = {
229 .read_time = palmas_rtc_read_time,
230 .set_time = palmas_rtc_set_time,
231 .read_alarm = palmas_rtc_read_alarm,
232 .set_alarm = palmas_rtc_set_alarm,
233 .alarm_irq_enable = palmas_rtc_alarm_irq_enable,
234 };
235
palmas_rtc_probe(struct platform_device * pdev)236 static int palmas_rtc_probe(struct platform_device *pdev)
237 {
238 struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
239 struct palmas_rtc *palmas_rtc = NULL;
240 int ret;
241 bool enable_bb_charging = false;
242 bool high_bb_charging = false;
243
244 if (pdev->dev.of_node) {
245 enable_bb_charging = of_property_read_bool(pdev->dev.of_node,
246 "ti,backup-battery-chargeable");
247 high_bb_charging = of_property_read_bool(pdev->dev.of_node,
248 "ti,backup-battery-charge-high-current");
249 }
250
251 palmas_rtc = devm_kzalloc(&pdev->dev, sizeof(struct palmas_rtc),
252 GFP_KERNEL);
253 if (!palmas_rtc)
254 return -ENOMEM;
255
256 /* Clear pending interrupts */
257 ret = palmas_clear_interrupts(&pdev->dev);
258 if (ret < 0) {
259 dev_err(&pdev->dev, "clear RTC int failed, err = %d\n", ret);
260 return ret;
261 }
262
263 palmas_rtc->dev = &pdev->dev;
264 platform_set_drvdata(pdev, palmas_rtc);
265
266 if (enable_bb_charging) {
267 unsigned reg = PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG;
268
269 if (high_bb_charging)
270 reg = 0;
271
272 ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
273 PALMAS_BACKUP_BATTERY_CTRL,
274 PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG, reg);
275 if (ret < 0) {
276 dev_err(&pdev->dev,
277 "BACKUP_BATTERY_CTRL update failed, %d\n", ret);
278 return ret;
279 }
280
281 ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
282 PALMAS_BACKUP_BATTERY_CTRL,
283 PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN,
284 PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN);
285 if (ret < 0) {
286 dev_err(&pdev->dev,
287 "BACKUP_BATTERY_CTRL update failed, %d\n", ret);
288 return ret;
289 }
290 }
291
292 /* Start RTC */
293 ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
294 PALMAS_RTC_CTRL_REG_STOP_RTC,
295 PALMAS_RTC_CTRL_REG_STOP_RTC);
296 if (ret < 0) {
297 dev_err(&pdev->dev, "RTC_CTRL write failed, err = %d\n", ret);
298 return ret;
299 }
300
301 palmas_rtc->irq = platform_get_irq(pdev, 0);
302
303 device_init_wakeup(&pdev->dev, 1);
304 palmas_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
305 &palmas_rtc_ops, THIS_MODULE);
306 if (IS_ERR(palmas_rtc->rtc)) {
307 ret = PTR_ERR(palmas_rtc->rtc);
308 dev_err(&pdev->dev, "RTC register failed, err = %d\n", ret);
309 return ret;
310 }
311
312 ret = devm_request_threaded_irq(&pdev->dev, palmas_rtc->irq, NULL,
313 palmas_rtc_interrupt,
314 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
315 dev_name(&pdev->dev), palmas_rtc);
316 if (ret < 0) {
317 dev_err(&pdev->dev, "IRQ request failed, err = %d\n", ret);
318 return ret;
319 }
320
321 return 0;
322 }
323
palmas_rtc_remove(struct platform_device * pdev)324 static int palmas_rtc_remove(struct platform_device *pdev)
325 {
326 palmas_rtc_alarm_irq_enable(&pdev->dev, 0);
327 return 0;
328 }
329
330 #ifdef CONFIG_PM_SLEEP
palmas_rtc_suspend(struct device * dev)331 static int palmas_rtc_suspend(struct device *dev)
332 {
333 struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
334
335 if (device_may_wakeup(dev))
336 enable_irq_wake(palmas_rtc->irq);
337 return 0;
338 }
339
palmas_rtc_resume(struct device * dev)340 static int palmas_rtc_resume(struct device *dev)
341 {
342 struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
343
344 if (device_may_wakeup(dev))
345 disable_irq_wake(palmas_rtc->irq);
346 return 0;
347 }
348 #endif
349
350 static SIMPLE_DEV_PM_OPS(palmas_rtc_pm_ops, palmas_rtc_suspend,
351 palmas_rtc_resume);
352
353 #ifdef CONFIG_OF
354 static const struct of_device_id of_palmas_rtc_match[] = {
355 { .compatible = "ti,palmas-rtc"},
356 { },
357 };
358 MODULE_DEVICE_TABLE(of, of_palmas_rtc_match);
359 #endif
360
361 static struct platform_driver palmas_rtc_driver = {
362 .probe = palmas_rtc_probe,
363 .remove = palmas_rtc_remove,
364 .driver = {
365 .name = "palmas-rtc",
366 .pm = &palmas_rtc_pm_ops,
367 .of_match_table = of_match_ptr(of_palmas_rtc_match),
368 },
369 };
370
371 module_platform_driver(palmas_rtc_driver);
372
373 MODULE_ALIAS("platform:palmas_rtc");
374 MODULE_DESCRIPTION("TI PALMAS series RTC driver");
375 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
376 MODULE_LICENSE("GPL v2");
377
