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 = rtc_device_register(pdev->name, &pdev->dev,
 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 = dev_get_drvdata(&pdev->dev);
 277
 278         rc5t583_rtc_alarm_irq_enable(&rc5t583_rtc->rtc->dev, 0);
 279
 280         rtc_device_unregister(rc5t583_rtc->rtc);
 281         return 0;
 282 }
 283
 284 #ifdef CONFIG_PM_SLEEP
 285
 286 static int rc5t583_rtc_suspend(struct device *dev)
 287 {
 288         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
 289         struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev);
 290         int ret;
 291
 292         /* Store current list of enabled interrupts*/
 293         ret = regmap_read(rc5t583->regmap, RC5T583_RTC_CTL1,
 294                 &rc5t583_rtc->irqen);
 295         return ret;
 296 }
 297
 298 static int rc5t583_rtc_resume(struct device *dev)
 299 {
 300         struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
 301         struct rc5t583_rtc *rc5t583_rtc = dev_get_drvdata(dev);
 302
 303         /* Restore list of enabled interrupts before suspend */
 304         return regmap_write(rc5t583->regmap, RC5T583_RTC_CTL1,
 305                 rc5t583_rtc->irqen);
 306 }
 307
 308 static const struct dev_pm_ops rc5t583_rtc_pm_ops = {
 309         .suspend        = rc5t583_rtc_suspend,
 310         .resume         = rc5t583_rtc_resume,
 311 };
 312
 313 #define DEV_PM_OPS     (&rc5t583_rtc_pm_ops)
 314 #else
 315 #define DEV_PM_OPS     NULL
 316 #endif
 317
 318 static struct platform_driver rc5t583_rtc_driver = {
 319         .probe          = rc5t583_rtc_probe,
 320         .remove         = rc5t583_rtc_remove,
 321         .driver         = {
 322                 .owner  = THIS_MODULE,
 323                 .name   = "rtc-rc5t583",
 324                 .pm     = DEV_PM_OPS,
 325         },
 326 };
 327
 328 module_platform_driver(rc5t583_rtc_driver);
 329 MODULE_ALIAS("platform:rtc-rc5t583");
 330 MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
 331 MODULE_LICENSE("GPL v2");