1 files changed, 349 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-tps65910.c b/drivers/rtc/rtc-tps65910.c
new file mode 100644
index 000000000000..7a82337e4dee
--- /dev/null
+++ b/drivers/rtc/rtc-tps65910.c
@@ -0,0 +1,349 @@
+/*
+ * rtc-tps65910.c -- TPS65910 Real Time Clock interface
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ * Author: Venu Byravarasu <vbyravarasu@nvidia.com>
+ *
+ * Based on original TI driver rtc-twl.c
+ *   Copyright (C) 2007 MontaVista Software, Inc
+ *   Author: Alexandre Rusev <source@mvista.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; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/tps65910.h>
+
+struct tps65910_rtc {
+        struct rtc_device       *rtc;
+        /* To store the list of enabled interrupts */
+        u32 irqstat;
+};
+
+/* Total number of RTC registers needed to set time*/
+#define NUM_TIME_REGS   (TPS65910_YEARS - TPS65910_SECONDS + 1)
+
+static int tps65910_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
+{
+        struct tps65910 *tps = dev_get_drvdata(dev->parent);
+        u8 val = 0;
+
+        if (enabled)
+                val = TPS65910_RTC_INTERRUPTS_IT_ALARM;
+
+        return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val);
+}
+
+/*
+ * Gets current tps65910 RTC time and date parameters.
+ *
+ * The RTC's time/alarm representation is not what gmtime(3) requires
+ * Linux to use:
+ *
+ *  - Months are 1..12 vs Linux 0-11
+ *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
+ */
+static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+        unsigned char rtc_data[NUM_TIME_REGS];
+        struct tps65910 *tps = dev_get_drvdata(dev->parent);
+        int ret;
+
+        /* Copy RTC counting registers to static registers or latches */
+        ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
+                TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME);
+        if (ret < 0) {
+                dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret);
+                return ret;
+        }
+
+        ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data,
+                NUM_TIME_REGS);
+        if (ret < 0) {
+                dev_err(dev, "reading from RTC failed with err:%d\n", ret);
+                return ret;
+        }
+
+        tm->tm_sec = bcd2bin(rtc_data[0]);
+        tm->tm_min = bcd2bin(rtc_data[1]);
+        tm->tm_hour = bcd2bin(rtc_data[2]);
+        tm->tm_mday = bcd2bin(rtc_data[3]);
+        tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
+        tm->tm_year = bcd2bin(rtc_data[5]) + 100;
+
+        return ret;
+}
+
+static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+        unsigned char rtc_data[NUM_TIME_REGS];
+        struct tps65910 *tps = dev_get_drvdata(dev->parent);
+        int ret;
+
+        rtc_data[0] = bin2bcd(tm->tm_sec);
+        rtc_data[1] = bin2bcd(tm->tm_min);
+        rtc_data[2] = bin2bcd(tm->tm_hour);
+        rtc_data[3] = bin2bcd(tm->tm_mday);
+        rtc_data[4] = bin2bcd(tm->tm_mon + 1);
+        rtc_data[5] = bin2bcd(tm->tm_year - 100);
+
+        /* Stop RTC while updating the RTC time registers */
+        ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
+                TPS65910_RTC_CTRL_STOP_RTC, 0);
+        if (ret < 0) {
+                dev_err(dev, "RTC stop failed with err:%d\n", ret);
+                return ret;
+        }
+
+        /* update all the time registers in one shot */
+        ret = regmap_bulk_write(tps->regmap, TPS65910_SECONDS, rtc_data,
+                NUM_TIME_REGS);
+        if (ret < 0) {
+                dev_err(dev, "rtc_set_time error %d\n", ret);
+                return ret;
+        }
+
+        /* Start back RTC */
+        ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
+                TPS65910_RTC_CTRL_STOP_RTC, 1);
+        if (ret < 0)
+                dev_err(dev, "RTC start failed with err:%d\n", ret);
+
+        return ret;
+}
+
+/*
+ * Gets current tps65910 RTC alarm time.
+ */
+static int tps65910_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+        unsigned char alarm_data[NUM_TIME_REGS];
+        u32 int_val;
+        struct tps65910 *tps = dev_get_drvdata(dev->parent);
+        int ret;
+
+        ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, alarm_data,
+                NUM_TIME_REGS);
+        if (ret < 0) {
+                dev_err(dev, "rtc_read_alarm error %d\n", ret);
+                return ret;
+        }
+
+        alm->time.tm_sec = bcd2bin(alarm_data[0]);
+        alm->time.tm_min = bcd2bin(alarm_data[1]);
+        alm->time.tm_hour = bcd2bin(alarm_data[2]);
+        alm->time.tm_mday = bcd2bin(alarm_data[3]);
+        alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
+        alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
+
+        ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, &int_val);
+        if (ret < 0)
+                return ret;
+
+        if (int_val & TPS65910_RTC_INTERRUPTS_IT_ALARM)
+                alm->enabled = 1;
+
+        return ret;
+}
+
+static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+        unsigned char alarm_data[NUM_TIME_REGS];
+        struct tps65910 *tps = dev_get_drvdata(dev->parent);
+        int ret;
+
+        ret = tps65910_rtc_alarm_irq_enable(dev, 0);
+        if (ret)
+                return ret;
+
+        alarm_data[0] = bin2bcd(alm->time.tm_sec);
+        alarm_data[1] = bin2bcd(alm->time.tm_min);
+        alarm_data[2] = bin2bcd(alm->time.tm_hour);
+        alarm_data[3] = bin2bcd(alm->time.tm_mday);
+        alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
+        alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
+
+        /* update all the alarm registers in one shot */
+        ret = regmap_bulk_write(tps->regmap, TPS65910_ALARM_SECONDS,
+                alarm_data, NUM_TIME_REGS);
+        if (ret) {
+                dev_err(dev, "rtc_set_alarm error %d\n", ret);
+                return ret;
+        }
+
+        if (alm->enabled)
+                ret = tps65910_rtc_alarm_irq_enable(dev, 1);
+
+        return ret;
+}
+
+static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc)
+{
+        struct device *dev = rtc;
+        unsigned long events = 0;
+        struct tps65910 *tps = dev_get_drvdata(dev->parent);
+        struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
+        int ret;
+        u32 rtc_reg;
+
+        ret = regmap_read(tps->regmap, TPS65910_RTC_STATUS, &rtc_reg);
+        if (ret)
+                return IRQ_NONE;
+
+        if (rtc_reg & TPS65910_RTC_STATUS_ALARM)
+                events = RTC_IRQF | RTC_AF;
+
+        ret = regmap_write(tps->regmap, TPS65910_RTC_STATUS, rtc_reg);
+        if (ret)
+                return IRQ_NONE;
+
+        /* Notify RTC core on event */
+        rtc_update_irq(tps_rtc->rtc, 1, events);
+
+        return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops tps65910_rtc_ops = {
+        .read_time      = tps65910_rtc_read_time,
+        .set_time       = tps65910_rtc_set_time,
+        .read_alarm     = tps65910_rtc_read_alarm,
+        .set_alarm      = tps65910_rtc_set_alarm,
+        .alarm_irq_enable = tps65910_rtc_alarm_irq_enable,
+};
+
+static int __devinit tps65910_rtc_probe(struct platform_device *pdev)
+{
+        struct tps65910 *tps65910 = NULL;
+        struct tps65910_rtc *tps_rtc = NULL;
+        int ret;
+        int irq;
+        u32 rtc_reg;
+
+        tps65910 = dev_get_drvdata(pdev->dev.parent);
+
+        tps_rtc = devm_kzalloc(&pdev->dev, sizeof(struct tps65910_rtc),
+                        GFP_KERNEL);
+        if (!tps_rtc)
+                return -ENOMEM;
+
+        /* Clear pending interrupts */
+        ret = regmap_read(tps65910->regmap, TPS65910_RTC_STATUS, &rtc_reg);
+        if (ret < 0)
+                return ret;
+
+        ret = regmap_write(tps65910->regmap, TPS65910_RTC_STATUS, rtc_reg);
+        if (ret < 0)
+                return ret;
+
+        dev_dbg(&pdev->dev, "Enabling rtc-tps65910.\n");
+        rtc_reg = TPS65910_RTC_CTRL_STOP_RTC;
+        ret = regmap_write(tps65910->regmap, TPS65910_RTC_CTRL, rtc_reg);
+        if (ret < 0)
+                return ret;
+
+        irq  = platform_get_irq(pdev, 0);
+        if (irq <= 0) {
+                dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n",
+                        irq);
+                return ret;
+        }
+
+        ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+                tps65910_rtc_interrupt, IRQF_TRIGGER_LOW,
+                "rtc-tps65910", &pdev->dev);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "IRQ is not free.\n");
+                return ret;
+        }
+        device_init_wakeup(&pdev->dev, 1);
+
+        tps_rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
+                &tps65910_rtc_ops, THIS_MODULE);
+        if (IS_ERR(tps_rtc->rtc)) {
+                ret = PTR_ERR(tps_rtc->rtc);
+                dev_err(&pdev->dev, "RTC device register: err %d\n", ret);
+                return ret;
+        }
+
+        platform_set_drvdata(pdev, tps_rtc);
+
+        return 0;
+}
+
+/*
+ * Disable tps65910 RTC interrupts.
+ * Sets status flag to free.
+ */
+static int __devexit tps65910_rtc_remove(struct platform_device *pdev)
+{
+        /* leave rtc running, but disable irqs */
+        struct rtc_device *rtc = platform_get_drvdata(pdev);
+
+        tps65910_rtc_alarm_irq_enable(&rtc->dev, 0);
+
+        rtc_device_unregister(rtc);
+        return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int tps65910_rtc_suspend(struct device *dev)
+{
+        struct tps65910 *tps = dev_get_drvdata(dev->parent);
+        u8 alarm = TPS65910_RTC_INTERRUPTS_IT_ALARM;
+        int ret;
+
+        /* Store current list of enabled interrupts*/
+        ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS,
+                &tps->rtc->irqstat);
+        if (ret < 0)
+                return ret;
+
+        /* Enable RTC ALARM interrupt only */
+        return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, alarm);
+}
+
+static int tps65910_rtc_resume(struct device *dev)
+{
+        struct tps65910 *tps = dev_get_drvdata(dev->parent);
+
+        /* Restore list of enabled interrupts before suspend */
+        return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS,
+                tps->rtc->irqstat);
+}
+
+static const struct dev_pm_ops tps65910_rtc_pm_ops = {
+        .suspend        = tps65910_rtc_suspend,
+        .resume         = tps65910_rtc_resume,
+};
+
+#define DEV_PM_OPS     (&tps65910_rtc_pm_ops)
+#else
+#define DEV_PM_OPS     NULL
+#endif
+
+static struct platform_driver tps65910_rtc_driver = {
+        .probe          = tps65910_rtc_probe,
+        .remove         = __devexit_p(tps65910_rtc_remove),
+        .driver         = {
+                .owner  = THIS_MODULE,
+                .name   = "tps65910-rtc",
+                .pm     = DEV_PM_OPS,
+        },
+};
+
+module_platform_driver(tps65910_rtc_driver);
+MODULE_ALIAS("platform:rtc-tps65910");
+MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
+MODULE_LICENSE("GPL");