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Linux/drivers/rtc/rtc-rc5t583.c

  1 /*
  2  * rtc-rc5t583.c -- RICOH RC5T583 Real Time Clock
  3  *
  4  * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
  5  * Author: Venu Byravarasu <vbyravarasu@nvidia.com>
  6  *
  7  * This program is free software; you can redistribute it and/or modify it
  8  * under the terms and conditions of the GNU General Public License,
  9  * version 2, as published by the Free Software Foundation.
 10  *
 11  * This program is distributed in the hope it will be useful, but WITHOUT
 12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 14  * more details.
 15  *
 16  * You should have received a copy of the GNU General Public License
 17  * along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 18 
 19 #include <linux/kernel.h>
 20 #include <linux/errno.h>
 21 #include <linux/init.h>
 22 #include <linux/module.h>
 23 #include <linux/types.h>
 24 #include <linux/rtc.h>
 25 #include <linux/bcd.h>
 26 #include <linux/platform_device.h>
 27 #include <linux/interrupt.h>
 28 #include <linux/mfd/rc5t583.h>
 29 
 30 struct rc5t583_rtc {
 31         struct rtc_device       *rtc;
 32         /* To store the list of enabled interrupts, during system suspend */
 33         u32 irqen;
 34 };
 35 
 36 /* Total number of RTC registers needed to set time*/
 37 #define NUM_TIME_REGS   (RC5T583_RTC_YEAR - RC5T583_RTC_SEC + 1)
 38 
 39 /* Total number of RTC registers needed to set Y-Alarm*/
 40 #define NUM_YAL_REGS    (RC5T583_RTC_AY_YEAR - RC5T583_RTC_AY_MIN + 1)
 41 
 42 /* Set Y-Alarm interrupt */
 43 #define SET_YAL BIT(5)
 44 
 45 /* Get Y-Alarm interrupt status*/
 46 #define GET_YAL_STATUS BIT(3)
 47 
 48 static int rc5t583_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
 49 {
 50         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
 51         u8 val;
 52 
 53         /* Set Y-Alarm, based on 'enabled' */
 54         val = enabled ? SET_YAL : 0;
 55 
 56         return regmap_update_bits(rc5t583->regmap, RC5T583_RTC_CTL1, SET_YAL,
 57                 val);
 58 }
 59 
 60 /*
 61  * Gets current rc5t583 RTC time and date parameters.
 62  *
 63  * The RTC's time/alarm representation is not what gmtime(3) requires
 64  * Linux to use:
 65  *
 66  *  - Months are 1..12 vs Linux 0-11
 67  *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
 68  */
 69 static int rc5t583_rtc_read_time(struct device *dev, struct rtc_time *tm)
 70 {
 71         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
 72         u8 rtc_data[NUM_TIME_REGS];
 73         int ret;
 74 
 75         ret = regmap_bulk_read(rc5t583->regmap, RC5T583_RTC_SEC, rtc_data,
 76                 NUM_TIME_REGS);
 77         if (ret < 0) {
 78                 dev_err(dev, "RTC read time failed with err:%d\n", ret);
 79                 return ret;
 80         }
 81 
 82         tm->tm_sec = bcd2bin(rtc_data[0]);
 83         tm->tm_min = bcd2bin(rtc_data[1]);
 84         tm->tm_hour = bcd2bin(rtc_data[2]);
 85         tm->tm_wday = bcd2bin(rtc_data[3]);
 86         tm->tm_mday = bcd2bin(rtc_data[4]);
 87         tm->tm_mon = bcd2bin(rtc_data[5]) - 1;
 88         tm->tm_year = bcd2bin(rtc_data[6]) + 100;
 89 
 90         return ret;
 91 }
 92 
 93 static int rc5t583_rtc_set_time(struct device *dev, struct rtc_time *tm)
 94 {
 95         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
 96         unsigned char rtc_data[NUM_TIME_REGS];
 97         int ret;
 98 
 99         rtc_data[0] = bin2bcd(tm->tm_sec);
100         rtc_data[1] = bin2bcd(tm->tm_min);
101         rtc_data[2] = bin2bcd(tm->tm_hour);
102         rtc_data[3] = bin2bcd(tm->tm_wday);
103         rtc_data[4] = bin2bcd(tm->tm_mday);
104         rtc_data[5] = bin2bcd(tm->tm_mon + 1);
105         rtc_data[6] = bin2bcd(tm->tm_year - 100);
106 
107         ret = regmap_bulk_write(rc5t583->regmap, RC5T583_RTC_SEC, rtc_data,
108                 NUM_TIME_REGS);
109         if (ret < 0) {
110                 dev_err(dev, "RTC set time failed with error %d\n", ret);
111                 return ret;
112         }
113 
114         return ret;
115 }
116 
117 static int rc5t583_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
118 {
119         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
120         unsigned char alarm_data[NUM_YAL_REGS];
121         u32 interrupt_enable;
122         int ret;
123 
124         ret = regmap_bulk_read(rc5t583->regmap, RC5T583_RTC_AY_MIN, alarm_data,
125                 NUM_YAL_REGS);
126         if (ret < 0) {
127                 dev_err(dev, "rtc_read_alarm error %d\n", ret);
128                 return ret;
129         }
130 
131         alm->time.tm_min = bcd2bin(alarm_data[0]);
132         alm->time.tm_hour = bcd2bin(alarm_data[1]);
133         alm->time.tm_mday = bcd2bin(alarm_data[2]);
134         alm->time.tm_mon = bcd2bin(alarm_data[3]) - 1;
135         alm->time.tm_year = bcd2bin(alarm_data[4]) + 100;
136 
137         ret = regmap_read(rc5t583->regmap, RC5T583_RTC_CTL1, &interrupt_enable);
138         if (ret < 0)
139                 return ret;
140 
141         /* check if YALE is set */
142         if (interrupt_enable & SET_YAL)
143                 alm->enabled = 1;
144 
145         return ret;
146 }
147 
148 static int rc5t583_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
149 {
150         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
151         unsigned char alarm_data[NUM_YAL_REGS];
152         int ret;
153 
154         ret = rc5t583_rtc_alarm_irq_enable(dev, 0);
155         if (ret)
156                 return ret;
157 
158         alarm_data[0] = bin2bcd(alm->time.tm_min);
159         alarm_data[1] = bin2bcd(alm->time.tm_hour);
160         alarm_data[2] = bin2bcd(alm->time.tm_mday);
161         alarm_data[3] = bin2bcd(alm->time.tm_mon + 1);
162         alarm_data[4] = bin2bcd(alm->time.tm_year - 100);
163 
164         ret = regmap_bulk_write(rc5t583->regmap, RC5T583_RTC_AY_MIN, alarm_data,
165                 NUM_YAL_REGS);
166         if (ret) {
167                 dev_err(dev, "rtc_set_alarm error %d\n", ret);
168                 return ret;
169         }
170 
171         if (alm->enabled)
172                 ret = rc5t583_rtc_alarm_irq_enable(dev, 1);
173 
174         return ret;
175 }
176 
177 static irqreturn_t rc5t583_rtc_interrupt(int irq, void *rtc)
178 {
179         struct device *dev = rtc;
180         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
181         struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev);
182         unsigned long events = 0;
183         int ret;
184         u32 rtc_reg;
185 
186         ret = regmap_read(rc5t583->regmap, RC5T583_RTC_CTL2, &rtc_reg);
187         if (ret < 0)
188                 return IRQ_NONE;
189 
190         if (rtc_reg & GET_YAL_STATUS) {
191                 events = RTC_IRQF | RTC_AF;
192                 /* clear pending Y-alarm interrupt bit */
193                 rtc_reg &= ~GET_YAL_STATUS;
194         }
195 
196         ret = regmap_write(rc5t583->regmap, RC5T583_RTC_CTL2, rtc_reg);
197         if (ret)
198                 return IRQ_NONE;
199 
200         /* Notify RTC core on event */
201         rtc_update_irq(rc5t583_rtc->rtc, 1, events);
202 
203         return IRQ_HANDLED;
204 }
205 
206 static const struct rtc_class_ops rc5t583_rtc_ops = {
207         .read_time      = rc5t583_rtc_read_time,
208         .set_time       = rc5t583_rtc_set_time,
209         .read_alarm     = rc5t583_rtc_read_alarm,
210         .set_alarm      = rc5t583_rtc_set_alarm,
211         .alarm_irq_enable = rc5t583_rtc_alarm_irq_enable,
212 };
213 
214 static int rc5t583_rtc_probe(struct platform_device *pdev)
215 {
216         struct rc5t583 *rc5t583 = dev_get_drvdata(pdev->dev.parent);
217         struct rc5t583_rtc *ricoh_rtc;
218         struct rc5t583_platform_data *pmic_plat_data;
219         int ret;
220         int irq;
221 
222         ricoh_rtc = devm_kzalloc(&pdev->dev, sizeof(struct rc5t583_rtc),
223                         GFP_KERNEL);
224         if (!ricoh_rtc)
225                 return -ENOMEM;
226 
227         platform_set_drvdata(pdev, ricoh_rtc);
228 
229         /* Clear pending interrupts */
230         ret = regmap_write(rc5t583->regmap, RC5T583_RTC_CTL2, 0);
231         if (ret < 0)
232                 return ret;
233 
234         /* clear RTC Adjust register */
235         ret = regmap_write(rc5t583->regmap, RC5T583_RTC_ADJ, 0);
236         if (ret < 0) {
237                 dev_err(&pdev->dev, "unable to program rtc_adjust reg\n");
238                 return -EBUSY;
239         }
240 
241         pmic_plat_data = dev_get_platdata(rc5t583->dev);
242         irq = pmic_plat_data->irq_base;
243         if (irq <= 0) {
244                 dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n",
245                         irq);
246                 return ret;
247         }
248 
249         irq += RC5T583_IRQ_YALE;
250         ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
251                 rc5t583_rtc_interrupt, IRQF_TRIGGER_LOW,
252                 "rtc-rc5t583", &pdev->dev);
253         if (ret < 0) {
254                 dev_err(&pdev->dev, "IRQ is not free.\n");
255                 return ret;
256         }
257         device_init_wakeup(&pdev->dev, 1);
258 
259         ricoh_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
260                 &rc5t583_rtc_ops, THIS_MODULE);
261         if (IS_ERR(ricoh_rtc->rtc)) {
262                 ret = PTR_ERR(ricoh_rtc->rtc);
263                 dev_err(&pdev->dev, "RTC device register: err %d\n", ret);
264                 return ret;
265         }
266 
267         return 0;
268 }
269 
270 /*
271  * Disable rc5t583 RTC interrupts.
272  * Sets status flag to free.
273  */
274 static int rc5t583_rtc_remove(struct platform_device *pdev)
275 {
276         struct rc5t583_rtc *rc5t583_rtc = platform_get_drvdata(pdev);
277 
278         rc5t583_rtc_alarm_irq_enable(&rc5t583_rtc->rtc->dev, 0);
279         return 0;
280 }
281 
282 #ifdef CONFIG_PM_SLEEP
283 static int rc5t583_rtc_suspend(struct device *dev)
284 {
285         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
286         struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev);
287         int ret;
288 
289         /* Store current list of enabled interrupts*/
290         ret = regmap_read(rc5t583->regmap, RC5T583_RTC_CTL1,
291                 &rc5t583_rtc->irqen);
292         return ret;
293 }
294 
295 static int rc5t583_rtc_resume(struct device *dev)
296 {
297         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
298         struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev);
299 
300         /* Restore list of enabled interrupts before suspend */
301         return regmap_write(rc5t583->regmap, RC5T583_RTC_CTL1,
302                 rc5t583_rtc->irqen);
303 }
304 #endif
305 
306 static SIMPLE_DEV_PM_OPS(rc5t583_rtc_pm_ops, rc5t583_rtc_suspend,
307                         rc5t583_rtc_resume);
308 
309 static struct platform_driver rc5t583_rtc_driver = {
310         .probe          = rc5t583_rtc_probe,
311         .remove         = rc5t583_rtc_remove,
312         .driver         = {
313                 .owner  = THIS_MODULE,
314                 .name   = "rtc-rc5t583",
315                 .pm     = &rc5t583_rtc_pm_ops,
316         },
317 };
318 
319 module_platform_driver(rc5t583_rtc_driver);
320 MODULE_ALIAS("platform:rtc-rc5t583");
321 MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
322 MODULE_LICENSE("GPL v2");
323 

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