1 files changed, 546 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-tps6591x.c b/drivers/rtc/rtc-tps6591x.c
new file mode 100644
index 00000000000..cab3e8874df
--- /dev/null
+++ b/drivers/rtc/rtc-tps6591x.c
@@ -0,0 +1,546 @@
+/*
+ * 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>
+
+#define RTC_CTRL                0x10
+#define RTC_STATUS              0x11
+#define RTC_SECONDS_REG         0x0
+#define RTC_ALARM               0x8
+#define RTC_INT                 0x12
+#define RTC_RESET_STATUS        0x16
+#define RTC_BBCH_REG            0x39
+
+#define RTC_BBCH_SEL            0x02
+#define RTC_BBCH_EN             0x01
+#define ENABLE_ALARM_INT 0x8
+#define RTC_RESET_VALUE 0x80
+#define ALARM_INT_STATUS 0x40
+
+/*
+Linux RTC driver refers 1900 as base year in many calculations.
+(e.g. refer drivers/rtc/rtc-lib.c)
+*/
+#define OS_REF_YEAR 1900
+
+/*
+        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 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;
+
+        /* dummy read of STATUS_REG as per data sheet */
+        ret = tps6591x_reads(dev->parent, RTC_STATUS, 1, val);
+        if (ret < 0) {
+                dev_err(dev->parent, "\n %s failed reading from RTC_STATUS\n",
+                        __func__);
+                WARN_ON(1);
+                return 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 >= (RTC_YEAR_OFFSET + 99)
+                || tm->tm_mon >= 12
+                || tm->tm_mday < 1
+                || tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + OS_REF_YEAR)
+                || tm->tm_hour >= 24
+                || tm->tm_min >= 60
+                || 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 device *dev, struct rtc_time *tm)
+{
+        dev_info(dev, "RTC Time : %d/%d/%d %d:%d:%d\n",
+                (tm->tm_mon + 1), tm->tm_mday, (tm->tm_year + OS_REF_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] - 1;
+        tm->tm_year = buff[5];
+        tm->tm_wday = buff[6];
+        print_time(dev, 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 + 1;
+        buff[5] = tm->tm_year;
+        buff[6] = tm->tm_wday;
+
+        print_time(dev, 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(dev->parent, &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) {
+                rtc->irq_en = true;
+        } else if (!alrm->enabled && rtc->irq_en) {
+                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 + 1;
+        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] - 1;
+        alrm->time.tm_year = buff[5];
+
+        dev_info(dev->parent, "\n getting alarm time::\n");
+        print_time(dev, &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 status bits.*/
+        err = tps6591x_read_regs(dev, RTC_STATUS, 1, &reg);
+        if (err) {
+                dev_err(dev->parent, "unable to read RTC_STATUS reg\n");
+                return -EBUSY;
+        }
+
+        reg = ALARM_INT_STATUS;
+        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 __devinit tps6591x_rtc_probe(struct platform_device *pdev)
+{
+        struct tps6591x_rtc_platform_data *pdata = pdev->dev.platform_data;
+        struct tps6591x_rtc *rtc;
+        struct rtc_time tm;
+        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);
+        device_init_wakeup(&pdev->dev, 1);
+        rtc->rtc = rtc_device_register(pdev->name, &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;
+        }
+
+        reg = RTC_BBCH_SEL | RTC_BBCH_EN;
+        tps6591x_write_regs(&pdev->dev, RTC_BBCH_REG, 1, &reg);
+        if (err) {
+                dev_err(&pdev->dev, "unable to program Charger reg\n");
+                return -EBUSY;
+        }
+
+        tps6591x_rtc_read_time(&pdev->dev, &tm);
+        if ((tm.tm_year < RTC_YEAR_OFFSET || tm.tm_year > (RTC_YEAR_OFFSET + 99))){
+                if (pdata->time.tm_year < 2000 || pdata->time.tm_year > 2100)   {
+                        memset(&pdata->time, 0, sizeof(pdata->time));
+                        pdata->time.tm_year = RTC_YEAR_OFFSET;
+                        pdata->time.tm_mday = 1;
+                } else
+                pdata->time.tm_year -= OS_REF_YEAR;
+                tps6591x_rtc_set_time(&pdev->dev, &pdata->time);
+        }
+
+        reg = ALARM_INT_STATUS;
+        err = tps6591x_write_regs(&pdev->dev, RTC_STATUS, 1, &reg);
+        if (err) {
+                dev_err(&pdev->dev, "unable to program RTC_STATUS reg\n");
+                return -EBUSY;
+        }
+
+        reg = ENABLE_ALARM_INT;
+        tps6591x_write_regs(&pdev->dev, RTC_INT, 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);
+                }
+        }
+        return 0;
+
+fail:
+        if (!IS_ERR_OR_NULL(rtc->rtc))
+                rtc_device_unregister(rtc->rtc);
+        kfree(rtc);
+        return err;
+}
+
+static int __devexit 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 = __devexit_p(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");