1 files changed, 403 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-ricoh583.c b/drivers/rtc/rtc-ricoh583.c
new file mode 100644
index 00000000000..8bc17d9a101
--- /dev/null
+++ b/drivers/rtc/rtc-ricoh583.c
@@ -0,0 +1,403 @@
+/*
+ * drivers/rtc/rtc_ricoh583.c
+ *
+ * rtc driver for ricoh rc5t583 pmu
+ *
+ * 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/ricoh583.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+#define rtc_ctrl1               0xED
+#define rtc_ctrl2               0xEE
+#define rtc_seconds_reg         0xE0
+#define rtc_alarm_y             0xF0
+#define rtc_adjust              0xE7
+
+/*
+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 ricoh583_rtc {
+        unsigned long           epoch_start;
+        int                     irq;
+        struct rtc_device       *rtc;
+        bool                    irq_en;
+};
+
+static int ricoh583_read_regs(struct device *dev, int reg, int len,
+        uint8_t *val)
+{
+        int ret;
+
+        ret = ricoh583_bulk_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;
+}
+
+static int ricoh583_write_regs(struct device *dev, int reg, int len,
+        uint8_t *val)
+{
+        int ret;
+        ret = ricoh583_bulk_writes(dev->parent, reg, len, val);
+        if (ret < 0) {
+                dev_err(dev->parent, "\n %s failed writing\n", __func__);
+                WARN_ON(1);
+        }
+
+        return ret;
+}
+
+static int ricoh583_rtc_valid_tm(struct device *dev, 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) {
+                dev_err(dev->parent, "\n returning error due to time"
+                "%d/%d/%d %d:%d:%d", tm->tm_mon, tm->tm_mday,
+                tm->tm_year, tm->tm_hour, tm->tm_min, tm->tm_sec);
+                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\n",
+                (tm->tm_mon + 1), tm->tm_mday, (tm->tm_year + os_ref_year),
+                tm->tm_hour, tm->tm_min);
+}
+
+static int ricoh583_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+        u8 buff[7];
+        int err;
+        err = ricoh583_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_wday = buff[3];
+        tm->tm_mday = buff[4];
+        tm->tm_mon  = buff[5] - 1;
+        tm->tm_year = buff[6] + rtc_year_offset;
+        print_time(dev, tm);
+        return ricoh583_rtc_valid_tm(dev, tm);
+}
+
+static int ricoh583_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+        u8 buff[7];
+        int err;
+
+        print_time(dev, tm);
+        buff[0] = tm->tm_sec;
+        buff[1] = tm->tm_min;
+        buff[2] = tm->tm_hour;
+        buff[3] = tm->tm_wday;
+        buff[4] = tm->tm_mday;
+        buff[5] = tm->tm_mon + 1;
+        buff[6] = tm->tm_year - rtc_year_offset;
+
+        convert_decimal_to_bcd(buff, sizeof(buff));
+        err = ricoh583_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;
+        }
+
+        return 0;
+}
+static int ricoh583_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm);
+
+static int ricoh583_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+        struct ricoh583_rtc *rtc = dev_get_drvdata(dev);
+        unsigned long seconds;
+        u8 buff[5];
+        int err;
+        struct rtc_time tm;
+
+        if (rtc->irq == -1)
+                return -EIO;
+
+        rtc_tm_to_time(&alrm->time, &seconds);
+        ricoh583_rtc_read_time(dev, &tm);
+        rtc_tm_to_time(&tm, &rtc->epoch_start);
+        /*
+                work around: As YAL does not provide the seconds register,
+                program minute register to next minute, in cases when alarm
+                is requested within a minute from the current time.
+        */
+        if (seconds - rtc->epoch_start < 60)
+                alrm->time.tm_min += 1;
+        dev_info(dev->parent, "\n setting alarm to requested time::\n");
+        print_time(dev->parent, &alrm->time);
+
+        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_min;
+        buff[1] = alrm->time.tm_hour;
+        buff[2] = alrm->time.tm_mday;
+        buff[3] = alrm->time.tm_mon + 1;
+        buff[4] = alrm->time.tm_year - rtc_year_offset;
+        convert_decimal_to_bcd(buff, sizeof(buff));
+        err = ricoh583_write_regs(dev, rtc_alarm_y, sizeof(buff), buff);
+        if (err) {
+                dev_err(dev->parent, "\n unable to set alarm\n");
+                return -EBUSY;
+        }
+        buff[0] = 0x20; /* to enable alarm_y */
+        buff[1] = 0x20; /* to enable 24-hour format */
+        err = ricoh583_write_regs(dev, rtc_ctrl1, 2, buff);
+        if (err) {
+                dev_err(dev, "failed programming rtc ctrl regs\n");
+                return -EBUSY;
+        }
+return err;
+}
+
+static int ricoh583_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+        u8 buff[5];
+        int err;
+
+        err = ricoh583_read_regs(dev, rtc_alarm_y, sizeof(buff), buff);
+        if (err)
+                return err;
+        convert_bcd_to_decimal(buff, sizeof(buff));
+
+        alrm->time.tm_min  = buff[0];
+        alrm->time.tm_hour = buff[1];
+        alrm->time.tm_mday = buff[2];
+        alrm->time.tm_mon  = buff[3] - 1;
+        alrm->time.tm_year = buff[4] + rtc_year_offset;
+
+        dev_info(dev->parent, "\n getting alarm time::\n");
+        print_time(dev, &alrm->time);
+
+        return 0;
+}
+
+static const struct rtc_class_ops ricoh583_rtc_ops = {
+        .read_time      = ricoh583_rtc_read_time,
+        .set_time       = ricoh583_rtc_set_time,
+        .set_alarm      = ricoh583_rtc_set_alarm,
+        .read_alarm     = ricoh583_rtc_read_alarm,
+};
+
+static irqreturn_t ricoh583_rtc_irq(int irq, void *data)
+{
+        struct device *dev = data;
+        struct ricoh583_rtc *rtc = dev_get_drvdata(dev);
+        u8 reg;
+        int err;
+
+        /* clear alarm-Y status bits.*/
+        err = ricoh583_read_regs(dev, rtc_ctrl2, 1, &reg);
+        if (err) {
+                dev_err(dev->parent, "unable to read rtc_ctrl2 reg\n");
+                return -EBUSY;
+        }
+        reg &= ~0x8;
+        err = ricoh583_write_regs(dev, rtc_ctrl2, 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 ricoh583_rtc_probe(struct platform_device *pdev)
+{
+        struct ricoh583_rtc_platform_data *pdata = pdev->dev.platform_data;
+        struct ricoh583_rtc *rtc;
+        struct rtc_time tm;
+        int err;
+        u8 reg[2];
+        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,
+                                       &ricoh583_rtc_ops, THIS_MODULE);
+
+        if (IS_ERR(rtc->rtc)) {
+                err = PTR_ERR(rtc->rtc);
+                goto fail;
+        }
+        reg[0] =  0; /* clearing RTC Adjust register */
+        err = ricoh583_write_regs(&pdev->dev, rtc_adjust, 1, reg);
+        if (err) {
+                dev_err(&pdev->dev, "unable to program rtc_adjust reg\n");
+                return -EBUSY;
+        }
+
+        reg[0] = 0x20; /* to enable alarm_y */
+        reg[1] = 0x20; /* to enable 24-hour format */
+        err = ricoh583_write_regs(&pdev->dev, rtc_ctrl1, 2, reg);
+        if (err) {
+                dev_err(&pdev->dev, "failed rtc setup\n");
+                return -EBUSY;
+        }
+
+        ricoh583_rtc_read_time(&pdev->dev, &tm);
+        if (ricoh583_rtc_valid_tm(&pdev->dev, &tm)) {
+                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;
+                ricoh583_rtc_set_time(&pdev->dev, &pdata->time);
+        }
+        if (pdata && (pdata->irq >= 0)) {
+                rtc->irq = pdata->irq;
+                err = request_threaded_irq(pdata->irq, NULL, ricoh583_rtc_irq,
+                                        IRQF_ONESHOT, "rtc_ricoh583",
+                                        &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 ricoh583_rtc_remove(struct platform_device *pdev)
+{
+        struct ricoh583_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 ricoh583_rtc_driver = {
+        .driver = {
+                .name   = "rtc_ricoh583",
+                .owner  = THIS_MODULE,
+        },
+        .probe  = ricoh583_rtc_probe,
+        .remove = __devexit_p(ricoh583_rtc_remove),
+};
+
+static int __init ricoh583_rtc_init(void)
+{
+        return platform_driver_register(&ricoh583_rtc_driver);
+}
+module_init(ricoh583_rtc_init);
+
+static void __exit ricoh583_rtc_exit(void)
+{
+        platform_driver_unregister(&ricoh583_rtc_driver);
+}
+module_exit(ricoh583_rtc_exit);
+
+MODULE_DESCRIPTION("RICOH PMU ricoh583 RTC driver");
+MODULE_AUTHOR("NVIDIA Corporation");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:rtc_ricoh583");