rtc: RTC driver for tps6591x
venu byravarasu [Thu, 3 Mar 2011 11:35:36 +0000 (16:35 +0530)]
With this check in native driver for TPS6591x RTC
is added to linux kernel.

Original-Change-Id: I267cc11b1451b8e2a4117cdff0b808f9f8fcc42a
Reviewed-on: http://git-master/r/20754
Tested-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>
Original-Change-Id: If55c1d1d7ebdedace4f0dea0b19bbda088a6cb1e

Rebase-Id: Rdd5b5c4b3c14b247608dffb5ee017051e802e5a1

drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-tps6591x.c [new file with mode: 0644]

index 0de99d0..13deabe 100644 (file)
@@ -1202,6 +1202,15 @@ config RTC_DRV_TILE
          Enable support for the Linux driver side of the Tilera
          hypervisor's real-time clock interface.
 
+config RTC_DRV_TPS6591x
+       tristate "TPS6591x RTC driver"
+       default RTC_CLASS
+       help
+         If you say yes here you get support for the TPS6591x RTC module.
+
+         This driver can also be built as a module. If so, the module
+         will be called rtc-tps6591x.
+
 config RTC_DRV_PUV3
        tristate "PKUnity v3 RTC support"
        depends on ARCH_PUV3
index e608e8b..b92a589 100644 (file)
@@ -118,6 +118,7 @@ obj-$(CONFIG_RTC_DRV_SUN4V) += rtc-sun4v.o
 obj-$(CONFIG_RTC_DRV_TEGRA)    += rtc-tegra.o
 obj-$(CONFIG_RTC_DRV_TEST)     += rtc-test.o
 obj-$(CONFIG_RTC_DRV_TILE)     += rtc-tile.o
+obj-$(CONFIG_RTC_DRV_TPS6591x) += rtc-tps6591x.o
 obj-$(CONFIG_RTC_DRV_TWL4030)  += rtc-twl.o
 obj-$(CONFIG_RTC_DRV_TPS6586X) += rtc-tps6586x.o
 obj-$(CONFIG_RTC_DRV_TPS65910) += rtc-tps65910.o
diff --git a/drivers/rtc/rtc-tps6591x.c b/drivers/rtc/rtc-tps6591x.c
new file mode 100644 (file)
index 0000000..5fba5cf
--- /dev/null
@@ -0,0 +1,500 @@
+/*
+ * drivers/rtc/rtc-tps6591x.c
+ *
+ * RTC driver for TI TPS6591x
+ *
+ * Copyright (c) 2011, NVIDIA Corporation.
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+/* #define DEBUG               1 */
+/* #define VERBOSE_DEBUG       1 */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mfd/tps6591x.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#define RTC_CTRL               0x10
+#define RTC_STATUS             0x11
+#define RTC_SECONDS_REG                0x0
+#define RTC_ALARM              0x8
+#define RTC_INT                        0x12
+#define RTC_INT_MASK           0x51
+#define RTC_RESET_STATUS       0x16
+
+struct tps6591x_rtc {
+       unsigned long           epoch_start;
+       int                     irq;
+       struct rtc_device       *rtc;
+       bool                    irq_en;
+};
+
+static int tps6591x_read_regs(struct device *dev, int reg, int len,
+       uint8_t *val)
+{
+       int ret;
+       ret = tps6591x_reads(dev->parent, reg, len, val);
+       if (ret < 0) {
+               dev_err(dev->parent, "\n %s failed reading from 0x%02x\n",
+                       __func__, reg);
+               WARN_ON(1);
+               return ret;
+       }
+       return 0;
+}
+
+static int tps6591x_write_regs(struct device *dev, int reg, int len,
+       uint8_t *val)
+{
+       int ret;
+       ret = tps6591x_writes(dev->parent, reg, len, val);
+       if (ret < 0) {
+               dev_err(dev->parent, "\n %s failed writing\n", __func__);
+               WARN_ON(1);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int tps6591x_rtc_valid_tm(struct rtc_time *tm)
+{
+       if (tm->tm_year <= 99
+               || ((unsigned)tm->tm_mon) >= 12
+               || tm->tm_mday < 1
+               || tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + 1900)
+               || ((unsigned)tm->tm_hour) >= 24
+               || ((unsigned)tm->tm_min) >= 60
+               || ((unsigned)tm->tm_sec) >= 60)
+               return -EINVAL;
+       return 0;
+}
+
+static u8 dec2bcd(u8 dec)
+{
+       return ((dec/10)<<4)+(dec%10);
+}
+
+static u8 bcd2dec(u8 bcd)
+{
+       return (bcd >> 4)*10+(bcd & 0xF);
+}
+
+static void convert_bcd_to_decimal(u8 *buf, u8 len)
+{
+       int i = 0;
+       for (i = 0; i < len; i++)
+               buf[i] = bcd2dec(buf[i]);
+}
+
+static void convert_decimal_to_bcd(u8 *buf, u8 len)
+{
+       int i = 0;
+       for (i = 0; i < len; i++)
+               buf[i] = dec2bcd(buf[i]);
+}
+
+static void print_time(struct rtc_time *tm)
+{
+       printk(KERN_INFO "\n TPS6591x RTC Time : %d-%d-%d %d:%d:%d\n",
+               tm->tm_mday, tm->tm_mon, tm->tm_year,
+               tm->tm_hour, tm->tm_min , tm->tm_sec);
+}
+
+static int tps6591x_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+       u8 buff[7];
+       int err;
+       err = tps6591x_read_regs(dev, RTC_SECONDS_REG, sizeof(buff), buff);
+       if (err < 0) {
+               dev_err(dev, "\n %s :: failed to read time\n", __FILE__);
+               return err;
+       }
+       convert_bcd_to_decimal(buff, sizeof(buff));
+       tm->tm_sec = buff[0];
+       tm->tm_min = buff[1];
+       tm->tm_hour = buff[2];
+       tm->tm_mday = buff[3];
+       tm->tm_mon = buff[4];
+       tm->tm_year = buff[5];
+       tm->tm_wday = buff[6];
+       print_time(tm);
+       return tps6591x_rtc_valid_tm(tm);
+}
+
+static int tps6591x_rtc_stop(struct device *dev)
+{
+       u8 reg = 0;
+       u8 retries = 0;
+       int err;
+       do {
+               err = tps6591x_read_regs(dev, RTC_CTRL, 1, &reg);
+               if (err < 0) {
+                       dev_err(dev->parent, "\n failed to read RTC_CTRL reg\n");
+                       return err;
+               }
+
+               /* clear STOP bit alone */
+               reg &= ~0x1;
+
+               err = tps6591x_write_regs(dev, RTC_CTRL, 1, &reg);
+               if (err < 0) {
+                       dev_err(dev->parent, "\n failed to program RTC_CTRL reg\n");
+                       return err;
+               }
+
+               err = tps6591x_read_regs(dev, RTC_STATUS, 1, &reg);
+               if (err < 0) {
+                       dev_err(dev->parent, "\n failed to read RTC_CTRL reg\n");
+                       return err;
+               }
+               /* FixMe: Is allowing up to 5 retries sufficient?? */
+               if (retries++ == 5) {
+                       dev_err(dev->parent, "\n failed to stop RTC\n");
+                       return -EBUSY;
+               }
+       }       while (reg & 2);
+       return 0;
+}
+
+static int tps6591x_rtc_start(struct device *dev)
+{
+       u8 reg = 0;
+       u8 retries = 0;
+       int err;
+
+       do {
+               err = tps6591x_read_regs(dev, RTC_CTRL, 1, &reg);
+               if (err < 0) {
+                       dev_err(dev->parent, "\n failed to read RTC_CTRL reg\n");
+                       return err;
+               }
+
+               /* set STOP bit alone */
+               reg |= 0x1;
+
+               err = tps6591x_write_regs(dev, RTC_CTRL, 1, &reg);
+               if (err < 0) {
+                       dev_err(dev->parent, "\n failed to program RTC_CTRL reg\n");
+                       return err;
+               }
+
+               err = tps6591x_read_regs(dev, RTC_STATUS, 1, &reg);
+               if (err < 0) {
+                       dev_err(dev->parent, "\n failed to read RTC_CTRL reg\n");
+                       return err;
+               }
+               /* FixMe: Is allowing up to 5 retries sufficient?? */
+               if (retries++ == 5) {
+                       dev_err(dev->parent, "\n failed to stop RTC\n");
+                       return -EBUSY;
+               }
+       }       while (!(reg & 2));
+       return 0;
+}
+
+
+static int tps6591x_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+       u8 buff[7];
+       int err;
+
+       buff[0] = tm->tm_sec;
+       buff[1] = tm->tm_min;
+       buff[2] = tm->tm_hour;
+       buff[3] = tm->tm_mday;
+       buff[4] = tm->tm_mon;
+       buff[5] = tm->tm_year;
+       buff[6] = tm->tm_wday;
+
+       print_time(tm);
+       convert_decimal_to_bcd(buff, sizeof(buff));
+       err = tps6591x_rtc_stop(dev);
+       if (err < 0) {
+               dev_err(dev->parent, "\n failed to clear RTC_ENABLE\n");
+               return err;
+       }
+
+       err = tps6591x_write_regs(dev, RTC_SECONDS_REG, sizeof(buff), buff);
+       if (err < 0) {
+               dev_err(dev->parent, "\n failed to program new time\n");
+               return err;
+       }
+
+       err = tps6591x_rtc_start(dev);
+       if (err < 0) {
+               dev_err(dev->parent, "\n failed to set RTC_ENABLE\n");
+               return err;
+       }
+
+       return 0;
+}
+
+static int tps6591x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       struct tps6591x_rtc *rtc = dev_get_drvdata(dev);
+       unsigned long seconds;
+       u8 buff[6];
+       int err;
+       struct rtc_time tm;
+
+       if (rtc->irq == -1)
+               return -EIO;
+
+       dev_info(dev->parent, "\n setting alarm to requested time::\n");
+       print_time(&alrm->time);
+       rtc_tm_to_time(&alrm->time, &seconds);
+       tps6591x_rtc_read_time(dev, &tm);
+       rtc_tm_to_time(&tm, &rtc->epoch_start);
+
+       if (WARN_ON(alrm->enabled && (seconds < rtc->epoch_start))) {
+               dev_err(dev->parent, "\n can't set alarm to requested time\n");
+               return -EINVAL;
+       }
+
+       if (alrm->enabled && !rtc->irq_en) {
+               enable_irq(rtc->irq);
+               rtc->irq_en = true;
+       } else if (!alrm->enabled && rtc->irq_en) {
+               disable_irq(rtc->irq);
+               rtc->irq_en = false;
+       }
+
+       buff[0] = alrm->time.tm_sec;
+       buff[1] = alrm->time.tm_min;
+       buff[2] = alrm->time.tm_hour;
+       buff[3] = alrm->time.tm_mday;
+       buff[4] = alrm->time.tm_mon;
+       buff[5] = alrm->time.tm_year;
+       convert_decimal_to_bcd(buff, sizeof(buff));
+       err = tps6591x_write_regs(dev, RTC_ALARM, sizeof(buff), buff);
+       if (err)
+               dev_err(dev->parent, "\n unable to program alarm\n");
+
+       return err;
+}
+
+static int tps6591x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       u8 buff[6];
+       int err;
+
+       err = tps6591x_read_regs(dev, RTC_ALARM, sizeof(buff), buff);
+       if (err)
+               return err;
+       convert_bcd_to_decimal(buff, sizeof(buff));
+
+       alrm->time.tm_sec = buff[0];
+       alrm->time.tm_min = buff[1];
+       alrm->time.tm_hour = buff[2];
+       alrm->time.tm_mday = buff[3];
+       alrm->time.tm_mon = buff[4];
+       alrm->time.tm_year = buff[5];
+
+       dev_info(dev->parent, "\n getting alarm time::\n");
+       print_time(&alrm->time);
+
+       return 0;
+}
+
+static int tps6591x_rtc_alarm_irq_enable(struct device *dev,
+                                        unsigned int enable)
+{
+       struct tps6591x_rtc *rtc = dev_get_drvdata(dev);
+       u8 reg;
+       int err;
+
+       if (rtc->irq == -1)
+               return -EIO;
+
+       if (enable) {
+               if (rtc->irq_en == true)
+                       return 0;
+               err = tps6591x_read_regs(dev, RTC_INT, 1, &reg);
+               if (err)
+                       return err;
+               reg |= 0x8;
+               err = tps6591x_write_regs(dev, RTC_INT, 1, &reg);
+               if (err)
+                       return err;
+               rtc->irq_en = true;
+       } else {
+               if (rtc->irq_en == false)
+                       return 0;
+               err = tps6591x_read_regs(dev, RTC_INT, 1, &reg);
+               if (err)
+                       return err;
+               reg &= ~0x8;
+               err = tps6591x_write_regs(dev, RTC_INT, 1, &reg);
+               if (err)
+                       return err;
+               rtc->irq_en = false;
+       }
+       return 0;
+}
+
+static const struct rtc_class_ops tps6591x_rtc_ops = {
+       .read_time      = tps6591x_rtc_read_time,
+       .set_time       = tps6591x_rtc_set_time,
+       .set_alarm      = tps6591x_rtc_set_alarm,
+       .read_alarm     = tps6591x_rtc_read_alarm,
+       .alarm_irq_enable = tps6591x_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t tps6591x_rtc_irq(int irq, void *data)
+{
+       struct device *dev = data;
+       struct tps6591x_rtc *rtc = dev_get_drvdata(dev);
+       u8 reg;
+       int err;
+
+       /* clear Alarm stray interrupt and Power_up status bits.*/
+       reg = 0xC0;
+       err = tps6591x_write_regs(dev, RTC_STATUS, 1, &reg);
+       if (err) {
+               dev_err(dev->parent, "unable to program RTC_STATUS reg\n");
+               return -EBUSY;
+       }
+
+       rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
+       return IRQ_HANDLED;
+}
+
+static int tps6591x_rtc_probe(struct platform_device *pdev)
+{
+       struct tps6591x_rtc_platform_data *pdata = pdev->dev.platform_data;
+       struct tps6591x_rtc *rtc;
+       int err;
+       u8 reg;
+
+       rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
+
+       if (!rtc)
+               return -ENOMEM;
+
+       rtc->irq = -1;
+
+       if (!pdata) {
+               dev_err(&pdev->dev, "no platform_data specified\n");
+               return -EINVAL;
+       }
+
+       if (pdata->irq < 0)
+               dev_err(&pdev->dev, "\n no IRQ specified, wakeup is disabled\n");
+
+       dev_set_drvdata(&pdev->dev, rtc);
+       rtc->rtc = rtc_device_register("rtc-tps6591x", &pdev->dev,
+                                      &tps6591x_rtc_ops, THIS_MODULE);
+
+       if (IS_ERR(rtc->rtc)) {
+               err = PTR_ERR(rtc->rtc);
+               goto fail;
+       }
+
+       if ((int)pdev && (int)&pdev->dev)
+               err = tps6591x_read_regs(&pdev->dev, RTC_STATUS, 1, &reg);
+       else {
+               dev_err(&pdev->dev, "\n %s Input params incorrect\n", __func__);
+               return -EBUSY;
+       }
+       if (err) {
+               dev_err(&pdev->dev, "\n %s unable to read status\n", __func__);
+               return -EBUSY;
+       }
+       if (reg & 0x80)
+               dev_info(&pdev->dev, "\n %s RTC reset occured\n", __func__);
+
+       /* cear Alarm stray interrupt and Power_up status bits.*/
+       reg = 0xC0;
+       tps6591x_write_regs(&pdev->dev, RTC_STATUS, 1, &reg);
+       if (err) {
+               dev_err(&pdev->dev, "unable to program RTC_STATUS reg\n");
+               return -EBUSY;
+       }
+
+       /* enable ALARM INT only */
+       reg = 0xBF;
+       tps6591x_write_regs(&pdev->dev, RTC_INT_MASK, 1, &reg);
+       if (err) {
+               dev_err(&pdev->dev, "unable to program Interrupt Mask reg\n");
+               return -EBUSY;
+       }
+
+       if (pdata && (pdata->irq >= 0)) {
+               rtc->irq = pdata->irq;
+               err = request_threaded_irq(pdata->irq, NULL, tps6591x_rtc_irq,
+                                          IRQF_ONESHOT, "rtc-tps6591x",
+                                          &pdev->dev);
+               if (err) {
+                       dev_err(&pdev->dev, "request IRQ:%d fail\n", rtc->irq);
+                       rtc->irq = -1;
+               } else {
+                       device_init_wakeup(&pdev->dev, 1);
+                       enable_irq_wake(rtc->irq);
+                       disable_irq(rtc->irq);
+               }
+       }
+       return 0;
+
+fail:
+       if (!IS_ERR_OR_NULL(rtc->rtc))
+               rtc_device_unregister(rtc->rtc);
+       kfree(rtc);
+       return err;
+}
+
+static int tps6591x_rtc_remove(struct platform_device *pdev)
+{
+       struct tps6591x_rtc *rtc = dev_get_drvdata(&pdev->dev);
+
+       if (rtc->irq != -1)
+               free_irq(rtc->irq, rtc);
+       rtc_device_unregister(rtc->rtc);
+       kfree(rtc);
+       return 0;
+}
+
+static struct platform_driver tps6591x_rtc_driver = {
+       .driver = {
+               .name   = "rtc-tps6591x",
+               .owner  = THIS_MODULE,
+       },
+       .probe  = tps6591x_rtc_probe,
+       .remove = tps6591x_rtc_remove,
+};
+
+static int __init tps6591x_rtc_init(void)
+{
+       return platform_driver_register(&tps6591x_rtc_driver);
+}
+module_init(tps6591x_rtc_init);
+
+static void __exit tps6591x_rtc_exit(void)
+{
+       platform_driver_unregister(&tps6591x_rtc_driver);
+}
+module_exit(tps6591x_rtc_exit);
+
+MODULE_DESCRIPTION("TI TPS6591x RTC driver");
+MODULE_AUTHOR("NVIDIA Corporation");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:rtc-tps6591x");