[RFC V1 2/2] rtc: da9063: RTC driver

[Opensource [Steve Twiss]]

From: Opensource [Steve Twiss] <stwiss.opensource@xxxxxxxxxxx>

Add the RTC driver for DA9063.

Signed-off-by: Opensource [Steve Twiss] <stwiss.opensource@xxxxxxxxxxx>
---
Checks performed with next-20140305/scripts/checkpatch.pl
 Kconfig                   total: 0 errors, 21 warnings, 1344 lines checked
 Makefile                  total: 0 errors, 0 warnings, 139 lines checked
 rtc-da9063.c              total: 0 errors, 0 warnings, 332 lines checked

Despite the 21 warnings from the Kconfig, these are not assocuated with
this patch.

This driver requires the register changes associated with this patch
set. In particular, the new register DA9063_REG_ALARM_S (now appearing
at addr=0x46) and DA9063_ALARM_S_MASK 0x3F are required to allow the
triggering of alarms down to the second resolution level.

This patch applies against kernel version linux-next next-20140305
 
Regards,
Steve Twiss, Dialog Semiconductor Ltd.



 drivers/rtc/Kconfig      |   10 ++
 drivers/rtc/Makefile     |    1 +
 drivers/rtc/rtc-da9063.c |  332 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 343 insertions(+)
 create mode 100644 drivers/rtc/rtc-da9063.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index db933de..472a5b9 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -746,6 +746,16 @@ 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 b427bf7..4a4fed9 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 0000000..26c506bb2
--- /dev/null
+++ b/drivers/rtc/rtc-da9063.c
@@ -0,0 +1,332 @@
+/* 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);
+
+	(void)rtc_tm_to_time(tm, &tm_secs);
+	(void)rtc_tm_to_time(&rtc->alarm_time, &al_secs);
+
+	/* handle the rtc synchronisation delay */
+	if (rtc->rtc_sync == true && al_secs - tm_secs == 1)
+		(void)memcpy((void *)tm, (const void *)&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);
+
+	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)) {
+		ret = PTR_ERR(rtc->rtc_dev);
+		goto err;
+	}
+
+	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);
+
+	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@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Real time clock device driver for Dialog DA9063");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DA9063_DRVNAME_RTC);
-- 
end-of-patch for RFC V1

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