Version:  2.0.40 2.2.26 2.4.37 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15

Linux/drivers/rtc/rtc-palmas.c

  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 
 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 
 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 
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 
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 
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 
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 
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 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 
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;
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                         IRQF_EARLY_RESUME,
316                         dev_name(&pdev->dev), palmas_rtc);
317         if (ret < 0) {
318                 dev_err(&pdev->dev, "IRQ request failed, err = %d\n", ret);
319                 return ret;
320         }
321 
322         return 0;
323 }
324 
325 static int palmas_rtc_remove(struct platform_device *pdev)
326 {
327         palmas_rtc_alarm_irq_enable(&pdev->dev, 0);
328         return 0;
329 }
330 
331 #ifdef CONFIG_PM_SLEEP
332 static int palmas_rtc_suspend(struct device *dev)
333 {
334         struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
335 
336         if (device_may_wakeup(dev))
337                 enable_irq_wake(palmas_rtc->irq);
338         return 0;
339 }
340 
341 static int palmas_rtc_resume(struct device *dev)
342 {
343         struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
344 
345         if (device_may_wakeup(dev))
346                 disable_irq_wake(palmas_rtc->irq);
347         return 0;
348 }
349 #endif
350 
351 static SIMPLE_DEV_PM_OPS(palmas_rtc_pm_ops, palmas_rtc_suspend,
352                          palmas_rtc_resume);
353 
354 #ifdef CONFIG_OF
355 static struct of_device_id of_palmas_rtc_match[] = {
356         { .compatible = "ti,palmas-rtc"},
357         { },
358 };
359 MODULE_DEVICE_TABLE(of, of_palmas_rtc_match);
360 #endif
361 
362 static struct platform_driver palmas_rtc_driver = {
363         .probe          = palmas_rtc_probe,
364         .remove         = palmas_rtc_remove,
365         .driver         = {
366                 .owner  = THIS_MODULE,
367                 .name   = "palmas-rtc",
368                 .pm     = &palmas_rtc_pm_ops,
369                 .of_match_table = of_match_ptr(of_palmas_rtc_match),
370         },
371 };
372 
373 module_platform_driver(palmas_rtc_driver);
374 
375 MODULE_ALIAS("platform:palmas_rtc");
376 MODULE_DESCRIPTION("TI PALMAS series RTC driver");
377 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
378 MODULE_LICENSE("GPL v2");
379 

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