rtc: add RTC driver for TPS80031/TPS80032
Laxman Dewangan [Fri, 22 Feb 2013 00:44:34 +0000 (16:44 -0800)]
Add an RTC driver for TPS80031/TPS80032 chips by TI.  This driver
supports:
 - Setting and getting time and date.
 - Setting and reading alarm time.
 - Alarm and interrupt functionlity.

[akpm@linux-foundation.org: remove obsolete __devinit/__devexit]
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-tps80031.c [new file with mode: 0644]

index e94ae65..d521834 100644 (file)
@@ -396,6 +396,14 @@ config RTC_DRV_TPS65910
          This driver can also be built as a module. If so, the module
          will be called rtc-tps65910.
 
+config RTC_DRV_TPS80031
+       tristate "TI TPS80031/TPS80032 RTC driver"
+       depends on MFD_TPS80031
+       help
+         TI Power Managment IC TPS80031 supports RTC functionality
+         along with alarm. This driver supports the RTC driver for
+         the TPS80031 RTC module.
+
 config RTC_DRV_RC5T583
        tristate "RICOH 5T583 RTC driver"
        depends on MFD_RC5T583
index 1a83776..cd03fb3 100644 (file)
@@ -116,6 +116,7 @@ obj-$(CONFIG_RTC_DRV_TILE)  += rtc-tile.o
 obj-$(CONFIG_RTC_DRV_TWL4030)  += rtc-twl.o
 obj-$(CONFIG_RTC_DRV_TPS6586X) += rtc-tps6586x.o
 obj-$(CONFIG_RTC_DRV_TPS65910) += rtc-tps65910.o
+obj-$(CONFIG_RTC_DRV_TPS80031) += rtc-tps80031.o
 obj-$(CONFIG_RTC_DRV_TX4939)   += rtc-tx4939.o
 obj-$(CONFIG_RTC_DRV_V3020)    += rtc-v3020.o
 obj-$(CONFIG_RTC_DRV_VR41XX)   += rtc-vr41xx.o
diff --git a/drivers/rtc/rtc-tps80031.c b/drivers/rtc/rtc-tps80031.c
new file mode 100644 (file)
index 0000000..9740641
--- /dev/null
@@ -0,0 +1,349 @@
+/*
+ * rtc-tps80031.c -- TI TPS80031/TPS80032 RTC driver
+ *
+ * RTC driver for TI TPS80031/TPS80032 Fully Integrated
+ * Power Management with Power Path and Battery Charger
+ *
+ * Copyright (c) 2012, NVIDIA Corporation.
+ *
+ * Author: Laxman Dewangan <ldewangan@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
+ * whether express or implied; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307, USA
+ */
+
+#include <linux/bcd.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/tps80031.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+#define ENABLE_ALARM_INT                       0x08
+#define ALARM_INT_STATUS                       0x40
+
+/**
+ * Setting bit to 1 in STOP_RTC will run the RTC and
+ * setting this bit to 0 will freeze RTC.
+ */
+#define STOP_RTC                               0x1
+
+/* Power on reset Values of RTC registers */
+#define TPS80031_RTC_POR_YEAR                  0
+#define TPS80031_RTC_POR_MONTH                 1
+#define TPS80031_RTC_POR_DAY                   1
+
+/* Numbers of registers for time and alarms */
+#define TPS80031_RTC_TIME_NUM_REGS             7
+#define TPS80031_RTC_ALARM_NUM_REGS            6
+
+/**
+ * PMU RTC have only 2 nibbles to store year information, so using an
+ * offset of 100 to set the base year as 2000 for our driver.
+ */
+#define RTC_YEAR_OFFSET 100
+
+struct tps80031_rtc {
+       struct rtc_device       *rtc;
+       int                     irq;
+};
+
+static int tps80031_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+       u8 buff[TPS80031_RTC_TIME_NUM_REGS];
+       int ret;
+
+       ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1,
+                       TPS80031_SECONDS_REG, TPS80031_RTC_TIME_NUM_REGS, buff);
+       if (ret < 0) {
+               dev_err(dev, "reading RTC_SECONDS_REG failed, err = %d\n", ret);
+               return ret;
+       }
+
+       tm->tm_sec = bcd2bin(buff[0]);
+       tm->tm_min = bcd2bin(buff[1]);
+       tm->tm_hour = bcd2bin(buff[2]);
+       tm->tm_mday = bcd2bin(buff[3]);
+       tm->tm_mon = bcd2bin(buff[4]) - 1;
+       tm->tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET;
+       tm->tm_wday = bcd2bin(buff[6]);
+       return 0;
+}
+
+static int tps80031_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+       u8 buff[7];
+       int ret;
+
+       buff[0] = bin2bcd(tm->tm_sec);
+       buff[1] = bin2bcd(tm->tm_min);
+       buff[2] = bin2bcd(tm->tm_hour);
+       buff[3] = bin2bcd(tm->tm_mday);
+       buff[4] = bin2bcd(tm->tm_mon + 1);
+       buff[5] = bin2bcd(tm->tm_year % RTC_YEAR_OFFSET);
+       buff[6] = bin2bcd(tm->tm_wday);
+
+       /* Stop RTC while updating the RTC time registers */
+       ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1,
+                               TPS80031_RTC_CTRL_REG, STOP_RTC);
+       if (ret < 0) {
+               dev_err(dev->parent, "Stop RTC failed, err = %d\n", ret);
+               return ret;
+       }
+
+       ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1,
+                       TPS80031_SECONDS_REG,
+                       TPS80031_RTC_TIME_NUM_REGS, buff);
+       if (ret < 0) {
+               dev_err(dev, "writing RTC_SECONDS_REG failed, err %d\n", ret);
+               return ret;
+       }
+
+       ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
+                               TPS80031_RTC_CTRL_REG, STOP_RTC);
+       if (ret < 0)
+               dev_err(dev->parent, "Start RTC failed, err = %d\n", ret);
+       return ret;
+}
+
+static int tps80031_rtc_alarm_irq_enable(struct device *dev,
+                                        unsigned int enable)
+{
+       int ret;
+
+       if (enable)
+               ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
+                               TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT);
+       else
+               ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1,
+                               TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT);
+       if (ret < 0) {
+               dev_err(dev, "Update on RTC_INT failed, err = %d\n", ret);
+               return ret;
+       }
+       return 0;
+}
+
+static int tps80031_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       u8 buff[TPS80031_RTC_ALARM_NUM_REGS];
+       int ret;
+
+       buff[0] = bin2bcd(alrm->time.tm_sec);
+       buff[1] = bin2bcd(alrm->time.tm_min);
+       buff[2] = bin2bcd(alrm->time.tm_hour);
+       buff[3] = bin2bcd(alrm->time.tm_mday);
+       buff[4] = bin2bcd(alrm->time.tm_mon + 1);
+       buff[5] = bin2bcd(alrm->time.tm_year % RTC_YEAR_OFFSET);
+       ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1,
+                       TPS80031_ALARM_SECONDS_REG,
+                       TPS80031_RTC_ALARM_NUM_REGS, buff);
+       if (ret < 0) {
+               dev_err(dev, "Writing RTC_ALARM failed, err %d\n", ret);
+               return ret;
+       }
+       return tps80031_rtc_alarm_irq_enable(dev, alrm->enabled);
+}
+
+static int tps80031_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       u8 buff[6];
+       int ret;
+
+       ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1,
+                       TPS80031_ALARM_SECONDS_REG,
+                       TPS80031_RTC_ALARM_NUM_REGS, buff);
+       if (ret < 0) {
+               dev_err(dev->parent,
+                       "reading RTC_ALARM failed, err = %d\n", ret);
+               return ret;
+       }
+
+       alrm->time.tm_sec = bcd2bin(buff[0]);
+       alrm->time.tm_min = bcd2bin(buff[1]);
+       alrm->time.tm_hour = bcd2bin(buff[2]);
+       alrm->time.tm_mday = bcd2bin(buff[3]);
+       alrm->time.tm_mon = bcd2bin(buff[4]) - 1;
+       alrm->time.tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET;
+       return 0;
+}
+
+static int clear_alarm_int_status(struct device *dev, struct tps80031_rtc *rtc)
+{
+       int ret;
+       u8 buf;
+
+       /**
+        * As per datasheet, A dummy read of this  RTC_STATUS_REG register
+        * is necessary before each I2C read in order to update the status
+        * register value.
+        */
+       ret = tps80031_read(dev->parent, TPS80031_SLAVE_ID1,
+                               TPS80031_RTC_STATUS_REG, &buf);
+       if (ret < 0) {
+               dev_err(dev, "reading RTC_STATUS failed. err = %d\n", ret);
+               return ret;
+       }
+
+       /* clear Alarm status bits.*/
+       ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
+                       TPS80031_RTC_STATUS_REG, ALARM_INT_STATUS);
+       if (ret < 0) {
+               dev_err(dev, "clear Alarm INT failed, err = %d\n", ret);
+               return ret;
+       }
+       return 0;
+}
+
+static irqreturn_t tps80031_rtc_irq(int irq, void *data)
+{
+       struct device *dev = data;
+       struct tps80031_rtc *rtc = dev_get_drvdata(dev);
+       int ret;
+
+       ret = clear_alarm_int_status(dev, rtc);
+       if (ret < 0)
+               return ret;
+
+       rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
+       return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops tps80031_rtc_ops = {
+       .read_time = tps80031_rtc_read_time,
+       .set_time = tps80031_rtc_set_time,
+       .set_alarm = tps80031_rtc_set_alarm,
+       .read_alarm = tps80031_rtc_read_alarm,
+       .alarm_irq_enable = tps80031_rtc_alarm_irq_enable,
+};
+
+static int tps80031_rtc_probe(struct platform_device *pdev)
+{
+       struct tps80031_rtc *rtc;
+       struct rtc_time tm;
+       int ret;
+
+       rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+       if (!rtc)
+               return -ENOMEM;
+
+       rtc->irq = platform_get_irq(pdev, 0);
+       platform_set_drvdata(pdev, rtc);
+
+       /* Start RTC */
+       ret = tps80031_set_bits(pdev->dev.parent, TPS80031_SLAVE_ID1,
+                       TPS80031_RTC_CTRL_REG, STOP_RTC);
+       if (ret < 0) {
+               dev_err(&pdev->dev, "failed to start RTC. err = %d\n", ret);
+               return ret;
+       }
+
+       /* If RTC have POR values, set time 01:01:2000 */
+       tps80031_rtc_read_time(&pdev->dev, &tm);
+       if ((tm.tm_year == RTC_YEAR_OFFSET + TPS80031_RTC_POR_YEAR) &&
+               (tm.tm_mon == (TPS80031_RTC_POR_MONTH - 1)) &&
+               (tm.tm_mday == TPS80031_RTC_POR_DAY)) {
+               tm.tm_year = 2000;
+               tm.tm_mday = 1;
+               tm.tm_mon = 1;
+               ret = tps80031_rtc_set_time(&pdev->dev, &tm);
+               if (ret < 0) {
+                       dev_err(&pdev->dev,
+                               "RTC set time failed, err = %d\n", ret);
+                       return ret;
+               }
+       }
+
+       /* Clear alarm intretupt status if it is there */
+       ret = clear_alarm_int_status(&pdev->dev, rtc);
+       if (ret < 0) {
+               dev_err(&pdev->dev, "Clear alarm int failed, err = %d\n", ret);
+               return ret;
+       }
+
+       rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
+                              &tps80031_rtc_ops, THIS_MODULE);
+       if (IS_ERR(rtc->rtc)) {
+               ret = PTR_ERR(rtc->rtc);
+               dev_err(&pdev->dev, "RTC registration failed, err %d\n", ret);
+               return ret;
+       }
+
+       ret = request_threaded_irq(rtc->irq, NULL, tps80031_rtc_irq,
+                       IRQF_ONESHOT | IRQF_EARLY_RESUME,
+                       dev_name(&pdev->dev), rtc);
+       if (ret < 0) {
+               dev_err(&pdev->dev, "request IRQ:%d failed, err = %d\n",
+                        rtc->irq, ret);
+               rtc_device_unregister(rtc->rtc);
+               return ret;
+       }
+       device_set_wakeup_capable(&pdev->dev, 1);
+       return 0;
+}
+
+static int tps80031_rtc_remove(struct platform_device *pdev)
+{
+       struct tps80031_rtc *rtc = platform_get_drvdata(pdev);
+
+       free_irq(rtc->irq, rtc);
+       rtc_device_unregister(rtc->rtc);
+       return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tps80031_rtc_suspend(struct device *dev)
+{
+       struct tps80031_rtc *rtc = dev_get_drvdata(dev);
+
+       if (device_may_wakeup(dev))
+               enable_irq_wake(rtc->irq);
+       return 0;
+}
+
+static int tps80031_rtc_resume(struct device *dev)
+{
+       struct tps80031_rtc *rtc = dev_get_drvdata(dev);
+
+       if (device_may_wakeup(dev))
+               disable_irq_wake(rtc->irq);
+       return 0;
+};
+#endif
+
+static const struct dev_pm_ops tps80031_pm_ops = {
+       SET_SYSTEM_SLEEP_PM_OPS(tps80031_rtc_suspend, tps80031_rtc_resume)
+};
+
+static struct platform_driver tps80031_rtc_driver = {
+       .driver = {
+               .name   = "tps80031-rtc",
+               .owner  = THIS_MODULE,
+               .pm     = &tps80031_pm_ops,
+       },
+       .probe  = tps80031_rtc_probe,
+       .remove = tps80031_rtc_remove,
+};
+
+module_platform_driver(tps80031_rtc_driver);
+
+MODULE_ALIAS("platform:tps80031-rtc");
+MODULE_DESCRIPTION("TI TPS80031/TPS80032 RTC driver");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
+MODULE_LICENSE("GPL v2");