rtc: da9063: RTC driver

Add the RTC driver for DA9063.

[akpm@linux-foundation.org: coding-style tweaks]
Signed-off-by: Opensource [Steve Twiss] <stwiss.opensource@diasemi.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Mark Brown <broonie@linaro.org>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: David Dajun Chen <david.chen@diasemi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 344 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 486d34b225d5..71988b69eca6 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -777,6 +777,16 @@ config RTC_DRV_DA9055
           This driver can also be built as a module. If so, the module
           will be called rtc-da9055
 
+config RTC_DRV_DA9063
+        tristate "Dialog Semiconductor DA9063 RTC"
+        depends on MFD_DA9063
+        help
+          If you say yes here you will get support for the RTC subsystem
+          of the Dialog Semiconductor DA9063.
+
+          This driver can also be built as a module. If so, the module
+          will be called "rtc-da9063".
+
 config RTC_DRV_EFI
         tristate "EFI RTC"
         depends on IA64
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 9d7775534a3d..70347d041d10 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_RTC_DRV_CMOS)	+= rtc-cmos.o
 obj-$(CONFIG_RTC_DRV_COH901331) += rtc-coh901331.o
 obj-$(CONFIG_RTC_DRV_DA9052)    += rtc-da9052.o
 obj-$(CONFIG_RTC_DRV_DA9055)    += rtc-da9055.o
+obj-$(CONFIG_RTC_DRV_DA9063)    += rtc-da9063.o
 obj-$(CONFIG_RTC_DRV_DAVINCI)   += rtc-davinci.o
 obj-$(CONFIG_RTC_DRV_DM355EVM)  += rtc-dm355evm.o
 obj-$(CONFIG_RTC_DRV_VRTC)      += rtc-mrst.o
diff --git a/drivers/rtc/rtc-da9063.c b/drivers/rtc/rtc-da9063.c
new file mode 100644
index 000000000000..595393098b09
--- /dev/null
+++ b/drivers/rtc/rtc-da9063.c
@@ -0,0 +1,333 @@
+/* rtc-da9063.c - Real time clock device driver for DA9063
+ * Copyright (C) 2013-14  Dialog Semiconductor Ltd.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/regmap.h>
+#include <linux/mfd/da9063/registers.h>
+#include <linux/mfd/da9063/core.h>
+
+#define YEARS_TO_DA9063(year)           ((year) - 100)
+#define MONTHS_TO_DA9063(month)         ((month) + 1)
+#define YEARS_FROM_DA9063(year)         ((year) + 100)
+#define MONTHS_FROM_DA9063(month)       ((month) - 1)
+
+#define RTC_DATA_LEN    (DA9063_REG_COUNT_Y - DA9063_REG_COUNT_S + 1)
+#define RTC_SEC         0
+#define RTC_MIN         1
+#define RTC_HOUR        2
+#define RTC_DAY         3
+#define RTC_MONTH       4
+#define RTC_YEAR        5
+
+struct da9063_rtc {
+        struct rtc_device       *rtc_dev;
+        struct da9063           *hw;
+        struct rtc_time         alarm_time;
+        bool                    rtc_sync;
+};
+
+static void da9063_data_to_tm(u8 *data, struct rtc_time *tm)
+{
+        tm->tm_sec  = data[RTC_SEC]  & DA9063_COUNT_SEC_MASK;
+        tm->tm_min  = data[RTC_MIN]  & DA9063_COUNT_MIN_MASK;
+        tm->tm_hour = data[RTC_HOUR] & DA9063_COUNT_HOUR_MASK;
+        tm->tm_mday = data[RTC_DAY]  & DA9063_COUNT_DAY_MASK;
+        tm->tm_mon  = MONTHS_FROM_DA9063(data[RTC_MONTH] &
+                                         DA9063_COUNT_MONTH_MASK);
+        tm->tm_year = YEARS_FROM_DA9063(data[RTC_YEAR] &
+                                        DA9063_COUNT_YEAR_MASK);
+}
+
+static void da9063_tm_to_data(struct rtc_time *tm, u8 *data)
+{
+        data[RTC_SEC] &= ~DA9063_COUNT_SEC_MASK;
+        data[RTC_SEC] |= tm->tm_sec & DA9063_COUNT_SEC_MASK;
+
+        data[RTC_MIN] &= ~DA9063_COUNT_MIN_MASK;
+        data[RTC_MIN] |= tm->tm_min & DA9063_COUNT_MIN_MASK;
+
+        data[RTC_HOUR] &= ~DA9063_COUNT_HOUR_MASK;
+        data[RTC_HOUR] |= tm->tm_hour & DA9063_COUNT_HOUR_MASK;
+
+        data[RTC_DAY] &= ~DA9063_COUNT_DAY_MASK;
+        data[RTC_DAY] |= tm->tm_mday & DA9063_COUNT_DAY_MASK;
+
+        data[RTC_MONTH] &= ~DA9063_COUNT_MONTH_MASK;
+        data[RTC_MONTH] |= MONTHS_TO_DA9063(tm->tm_mon) &
+                                DA9063_COUNT_MONTH_MASK;
+
+        data[RTC_YEAR] &= ~DA9063_COUNT_YEAR_MASK;
+        data[RTC_YEAR] |= YEARS_TO_DA9063(tm->tm_year) &
+                                DA9063_COUNT_YEAR_MASK;
+}
+
+static int da9063_rtc_stop_alarm(struct device *dev)
+{
+        struct da9063_rtc *rtc = dev_get_drvdata(dev);
+
+        return regmap_update_bits(rtc->hw->regmap, DA9063_REG_ALARM_Y,
+                                  DA9063_ALARM_ON, 0);
+}
+
+static int da9063_rtc_start_alarm(struct device *dev)
+{
+        struct da9063_rtc *rtc = dev_get_drvdata(dev);
+
+        return regmap_update_bits(rtc->hw->regmap, DA9063_REG_ALARM_Y,
+                                  DA9063_ALARM_ON, DA9063_ALARM_ON);
+}
+
+static int da9063_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+        struct da9063_rtc *rtc = dev_get_drvdata(dev);
+        unsigned long tm_secs;
+        unsigned long al_secs;
+        u8 data[RTC_DATA_LEN];
+        int ret;
+
+        ret = regmap_bulk_read(rtc->hw->regmap, DA9063_REG_COUNT_S,
+                               data, RTC_DATA_LEN);
+        if (ret < 0) {
+                dev_err(dev, "Failed to read RTC time data: %d\n", ret);
+                return ret;
+        }
+
+        if (!(data[RTC_SEC] & DA9063_RTC_READ)) {
+                dev_dbg(dev, "RTC not yet ready to be read by the host\n");
+                return -EINVAL;
+        }
+
+        da9063_data_to_tm(data, tm);
+
+        rtc_tm_to_time(tm, &tm_secs);
+        rtc_tm_to_time(&rtc->alarm_time, &al_secs);
+
+        /* handle the rtc synchronisation delay */
+        if (rtc->rtc_sync == true && al_secs - tm_secs == 1)
+                memcpy(tm, &rtc->alarm_time, sizeof(struct rtc_time));
+        else
+                rtc->rtc_sync = false;
+
+        return rtc_valid_tm(tm);
+}
+
+static int da9063_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+        struct da9063_rtc *rtc = dev_get_drvdata(dev);
+        u8 data[RTC_DATA_LEN];
+        int ret;
+
+        da9063_tm_to_data(tm, data);
+        ret = regmap_bulk_write(rtc->hw->regmap, DA9063_REG_COUNT_S,
+                                data, RTC_DATA_LEN);
+        if (ret < 0)
+                dev_err(dev, "Failed to set RTC time data: %d\n", ret);
+
+        return ret;
+}
+
+static int da9063_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+        struct da9063_rtc *rtc = dev_get_drvdata(dev);
+        u8 data[RTC_DATA_LEN];
+        int ret;
+        unsigned int val;
+
+        ret = regmap_bulk_read(rtc->hw->regmap, DA9063_REG_ALARM_S,
+                               &data[RTC_SEC], RTC_DATA_LEN);
+        if (ret < 0)
+                return ret;
+
+        da9063_data_to_tm(data, &alrm->time);
+
+        alrm->enabled = !!(data[RTC_YEAR] & DA9063_ALARM_ON);
+
+        ret = regmap_read(rtc->hw->regmap, DA9063_REG_EVENT_A, &val);
+        if (ret < 0)
+                return ret;
+
+        if (val & (DA9063_E_ALARM))
+                alrm->pending = 1;
+        else
+                alrm->pending = 0;
+
+        return 0;
+}
+
+static int da9063_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+        struct da9063_rtc *rtc = dev_get_drvdata(dev);
+        u8 data[RTC_DATA_LEN];
+        int ret;
+
+        da9063_tm_to_data(&alrm->time, data);
+
+        ret = da9063_rtc_stop_alarm(dev);
+        if (ret < 0) {
+                dev_err(dev, "Failed to stop alarm: %d\n", ret);
+                return ret;
+        }
+
+        ret = regmap_bulk_write(rtc->hw->regmap, DA9063_REG_ALARM_S,
+                                data, RTC_DATA_LEN);
+        if (ret < 0) {
+                dev_err(dev, "Failed to write alarm: %d\n", ret);
+                return ret;
+        }
+
+        rtc->alarm_time = alrm->time;
+
+        if (alrm->enabled) {
+                ret = da9063_rtc_start_alarm(dev);
+                if (ret < 0) {
+                        dev_err(dev, "Failed to start alarm: %d\n", ret);
+                        return ret;
+                }
+        }
+
+        return ret;
+}
+
+static int da9063_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+        if (enabled)
+                return da9063_rtc_start_alarm(dev);
+        else
+                return da9063_rtc_stop_alarm(dev);
+}
+
+static irqreturn_t da9063_alarm_event(int irq, void *data)
+{
+        struct da9063_rtc *rtc = data;
+
+        regmap_update_bits(rtc->hw->regmap, DA9063_REG_ALARM_Y,
+                           DA9063_ALARM_ON, 0);
+
+        rtc->rtc_sync = true;
+        rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
+
+        return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops da9063_rtc_ops = {
+        .read_time = da9063_rtc_read_time,
+        .set_time = da9063_rtc_set_time,
+        .read_alarm = da9063_rtc_read_alarm,
+        .set_alarm = da9063_rtc_set_alarm,
+        .alarm_irq_enable = da9063_rtc_alarm_irq_enable,
+};
+
+static int da9063_rtc_probe(struct platform_device *pdev)
+{
+        struct da9063 *da9063 = dev_get_drvdata(pdev->dev.parent);
+        struct da9063_rtc *rtc;
+        int irq_alarm;
+        u8 data[RTC_DATA_LEN];
+        int ret;
+
+        ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_E,
+                                 DA9063_RTC_EN, DA9063_RTC_EN);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "Failed to enable RTC\n");
+                goto err;
+        }
+
+        ret = regmap_update_bits(da9063->regmap, DA9063_REG_EN_32K,
+                                 DA9063_CRYSTAL, DA9063_CRYSTAL);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "Failed to run 32kHz oscillator\n");
+                goto err;
+        }
+
+        ret = regmap_update_bits(da9063->regmap, DA9063_REG_ALARM_S,
+                        DA9063_ALARM_STATUS_TICK | DA9063_ALARM_STATUS_ALARM,
+                        0);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "Failed to access RTC alarm register\n");
+                goto err;
+        }
+
+        ret = regmap_update_bits(da9063->regmap, DA9063_REG_ALARM_S,
+                                 DA9063_ALARM_STATUS_ALARM,
+                                 DA9063_ALARM_STATUS_ALARM);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "Failed to access RTC alarm register\n");
+                goto err;
+        }
+
+        ret = regmap_update_bits(da9063->regmap, DA9063_REG_ALARM_Y,
+                                 DA9063_TICK_ON, 0);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "Failed to disable TICKs\n");
+                goto err;
+        }
+
+        ret = regmap_bulk_read(da9063->regmap, DA9063_REG_ALARM_S,
+                               data, RTC_DATA_LEN);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "Failed to read initial alarm data: %d\n",
+                        ret);
+                goto err;
+        }
+
+        rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+        if (!rtc)
+                return -ENOMEM;
+
+        platform_set_drvdata(pdev, rtc);
+
+        irq_alarm = platform_get_irq_byname(pdev, "ALARM");
+        ret = devm_request_threaded_irq(&pdev->dev, irq_alarm, NULL,
+                                        da9063_alarm_event,
+                                        IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+                                        "ALARM", rtc);
+        if (ret) {
+                dev_err(&pdev->dev, "Failed to request ALARM IRQ %d: %d\n",
+                        irq_alarm, ret);
+                goto err;
+        }
+
+        rtc->hw = da9063;
+        rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, DA9063_DRVNAME_RTC,
+                                           &da9063_rtc_ops, THIS_MODULE);
+        if (IS_ERR(rtc->rtc_dev))
+                return PTR_ERR(rtc->rtc_dev);
+
+        da9063_data_to_tm(data, &rtc->alarm_time);
+        rtc->rtc_sync = false;
+err:
+        return ret;
+}
+
+static struct platform_driver da9063_rtc_driver = {
+        .probe          = da9063_rtc_probe,
+        .driver         = {
+                .name   = DA9063_DRVNAME_RTC,
+                .owner  = THIS_MODULE,
+        },
+};
+
+module_platform_driver(da9063_rtc_driver);
+
+MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
+MODULE_DESCRIPTION("Real time clock device driver for Dialog DA9063");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DA9063_DRVNAME_RTC);