Patchwork [4/4] drivers/rtc/rtc-as3722: add RTC driver

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Submitter Laxman Dewangan
Date Sept. 17, 2013, 6:45 a.m.
Message ID <1379400338-20704-5-git-send-email-ldewangan@nvidia.com>
Download mbox | patch
Permalink /patch/275378/
State New
Headers show

Comments

Laxman Dewangan - Sept. 17, 2013, 6:45 a.m.
The AS3722 is a compact system PMU suitable for Mobile Phones, Tablet etc.

Add a driver to support accessing the RTC found on the AMS AS3722
PMIC using RTC framework.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Florian Lobmaier <florian.lobmaier@ams.com>
---
 .../devicetree/bindings/rtc/rtc-as3722.txt         |   21 ++
 drivers/rtc/Kconfig                                |   10 +
 drivers/rtc/Makefile                               |    1 +
 drivers/rtc/rtc-as3722.c                           |  315 ++++++++++++++++++++
 4 files changed, 347 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/rtc/rtc-as3722.txt
 create mode 100644 drivers/rtc/rtc-as3722.c
Mark Brown - Sept. 17, 2013, 11:43 a.m.
On Tue, Sep 17, 2013 at 12:15:38PM +0530, Laxman Dewangan wrote:

> +Optional properties:
> +-------------------
> +ams,enable_clk32k_out: Enable CLK32K output.

This looks like it should be being supported via the clock API?  This
sort of thing is one of the reasons why I'm not too keen on representing
the MFD structure directly in the DT.

Patch

diff --git a/Documentation/devicetree/bindings/rtc/rtc-as3722.txt b/Documentation/devicetree/bindings/rtc/rtc-as3722.txt
new file mode 100644
index 0000000..17a9671
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/rtc-as3722.txt
@@ -0,0 +1,21 @@ 
+AMS AS3722 RTC bindings.
+This describe the properties of the rtc sub-node of the AMS AS3722 device tree.
+
+Required properties:
+--------------------
+- compatible: Must be "ams,as3722-rtc".
+
+Optional properties:
+-------------------
+ams,enable_clk32k_out: Enable CLK32K output.
+
+Example:
+	ams3722:: ams3722 {
+		compatible = "ams,as3722";
+		...
+		rtc {
+			compatible = "ams,as3722-rtc";
+			ams,enable_clk32k_out;
+		};
+		...
+	};
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 9654aa3..3a17788 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -153,6 +153,16 @@  config RTC_DRV_88PM80X
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-88pm80x.
 
+config RTC_DRV_AS3722
+	tristate "AMS AS3722 RTC driver"
+	depends on MFD_AS3722
+	help
+	  If you say yes here you get support for the RTC of AMS AS3722 PMIC
+	  chips.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-as3722.
+
 config RTC_DRV_DS1307
 	tristate "Dallas/Maxim DS1307/37/38/39/40, ST M41T00, EPSON RX-8025"
 	help
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 2dff3d2..fdb5764 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -20,6 +20,7 @@  obj-$(CONFIG_RTC_DRV_88PM860X)  += rtc-88pm860x.o
 obj-$(CONFIG_RTC_DRV_88PM80X)	+= rtc-88pm80x.o
 obj-$(CONFIG_RTC_DRV_AB3100)	+= rtc-ab3100.o
 obj-$(CONFIG_RTC_DRV_AB8500)	+= rtc-ab8500.o
+obj-$(CONFIG_RTC_DRV_AS3722)	+= rtc-as3722.o
 obj-$(CONFIG_RTC_DRV_AT32AP700X)+= rtc-at32ap700x.o
 obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o
 obj-$(CONFIG_RTC_DRV_AT91SAM9)	+= rtc-at91sam9.o
diff --git a/drivers/rtc/rtc-as3722.c b/drivers/rtc/rtc-as3722.c
new file mode 100644
index 0000000..4c264ac
--- /dev/null
+++ b/drivers/rtc/rtc-as3722.c
@@ -0,0 +1,315 @@ 
+/*
+ * rtc-as3722.c - Real Time Clock driver for ams AS3722 PMICs
+ *
+ * Copyright (C) 2013 ams AG
+ * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
+ *
+ * Author: Florian Lobmaier <florian.lobmaier@ams.com>
+ * Author: Laxman Dewangan <ldewangan@nvidia.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.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/bcd.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/ioctl.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/as3722.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/time.h>
+
+#define AS3722_RTC_START_YEAR	  2000
+struct as3722_rtc {
+	struct rtc_device	*rtc;
+	struct device		*dev;
+	struct as3722		*as3722;
+	int			alarm_irq;
+	bool			irq_enable;
+	bool			enable_clk32k_out;
+};
+
+static void as3722_time_to_reg(u8 *rbuff, struct rtc_time *tm)
+{
+	rbuff[0] = bin2bcd(tm->tm_sec);
+	rbuff[1] = bin2bcd(tm->tm_min);
+	rbuff[2] = bin2bcd(tm->tm_hour);
+	rbuff[3] = bin2bcd(tm->tm_mday);
+	rbuff[4] = bin2bcd(tm->tm_mon);
+	rbuff[5] = bin2bcd(tm->tm_year - (AS3722_RTC_START_YEAR - 1900));
+}
+
+static void as3722_reg_to_time(u8 *rbuff, struct rtc_time *tm)
+{
+	tm->tm_sec = bcd2bin(rbuff[0] & 0x7F);
+	tm->tm_min = bcd2bin(rbuff[1] & 0x7F);
+	tm->tm_hour = bcd2bin(rbuff[2] & 0x3F);
+	tm->tm_mday = bcd2bin(rbuff[3] & 0x3F);
+	tm->tm_mon = bcd2bin(rbuff[4] & 0x1F);
+	tm->tm_year = (AS3722_RTC_START_YEAR - 1900) + bcd2bin(rbuff[5] & 0x7F);
+	return;
+}
+
+static int as3722_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
+	struct as3722 *as3722 = as3722_rtc->as3722;
+	u8 as_time_array[6];
+	int ret;
+
+	ret = as3722_block_read(as3722, AS3722_RTC_SECOND_REG,
+			6, as_time_array);
+	if (ret < 0) {
+		dev_err(dev, "RTC_SECOND reg block read failed %d\n", ret);
+		return ret;
+	}
+	as3722_reg_to_time(as_time_array, tm);
+	return 0;
+}
+
+static int as3722_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
+	struct as3722 *as3722 = as3722_rtc->as3722;
+	u8 as_time_array[6];
+	int ret;
+
+	if (tm->tm_year < (AS3722_RTC_START_YEAR - 1900))
+		return -EINVAL;
+
+	as3722_time_to_reg(as_time_array, tm);
+	ret = as3722_block_write(as3722, AS3722_RTC_SECOND_REG, 6,
+			as_time_array);
+	if (ret < 0)
+		dev_err(dev, "RTC_SECOND reg block write failed %d\n", ret);
+	return ret;
+}
+
+static int as3722_rtc_alarm_irq_enable(struct device *dev,
+		unsigned int enabled)
+{
+	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
+
+	if (enabled && !as3722_rtc->irq_enable) {
+		enable_irq(as3722_rtc->alarm_irq);
+		as3722_rtc->irq_enable = true;
+	} else if (!enabled && as3722_rtc->irq_enable)  {
+		disable_irq(as3722_rtc->alarm_irq);
+		as3722_rtc->irq_enable = false;
+	}
+	return 0;
+}
+
+static int as3722_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
+	struct as3722 *as3722 = as3722_rtc->as3722;
+	u8 as_time_array[6];
+	int ret;
+
+	ret = as3722_block_read(as3722, AS3722_RTC_ALARM_SECOND_REG, 6,
+			as_time_array);
+	if (ret < 0) {
+		dev_err(dev, "RTC_ALARM_SECOND block read failed %d\n", ret);
+		return ret;
+	}
+
+	as3722_reg_to_time(as_time_array, &alrm->time);
+	return 0;
+}
+
+static int as3722_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
+	struct as3722 *as3722 = as3722_rtc->as3722;
+	u8 as_time_array[6];
+	int ret;
+
+	if (alrm->time.tm_year < (AS3722_RTC_START_YEAR - 1900))
+		return -EINVAL;
+
+	ret = as3722_rtc_alarm_irq_enable(dev, 0);
+	if (ret < 0) {
+		dev_err(dev, "Disable RTC alarm failed\n");
+		return ret;
+	}
+
+	as3722_time_to_reg(as_time_array, &alrm->time);
+	ret = as3722_block_write(as3722, AS3722_RTC_ALARM_SECOND_REG, 6,
+			as_time_array);
+	if (ret < 0) {
+		dev_err(dev, "RTC_ALARM_SECOND block write failed %d\n", ret);
+		return ret;
+	}
+
+	if (alrm->enabled)
+		ret = as3722_rtc_alarm_irq_enable(dev, alrm->enabled);
+	return ret;
+}
+
+static irqreturn_t as3722_alarm_irq(int irq, void *data)
+{
+	struct as3722_rtc *as3722_rtc = data;
+
+	rtc_update_irq(as3722_rtc->rtc, 1, RTC_IRQF | RTC_AF);
+	return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops as3722_rtc_ops = {
+	.read_time = as3722_rtc_read_time,
+	.set_time = as3722_rtc_set_time,
+	.read_alarm = as3722_rtc_read_alarm,
+	.set_alarm = as3722_rtc_set_alarm,
+	.alarm_irq_enable = as3722_rtc_alarm_irq_enable,
+};
+
+static int as3722_get_rtc_dt_data(struct platform_device *pdev,
+		struct as3722_rtc *as3722_rtc)
+{
+	struct device_node *np = pdev->dev.of_node;
+
+	if (np)
+		as3722_rtc->enable_clk32k_out = of_property_read_bool(np,
+						"ams,enable_clk32k_out");
+	return 0;
+}
+
+static int as3722_rtc_probe(struct platform_device *pdev)
+{
+	struct as3722 *as3722 = dev_get_drvdata(pdev->dev.parent);
+	struct as3722_rtc *as3722_rtc;
+	bool enable_clk32k_out;
+	int val;
+	int ret;
+
+	as3722_rtc = devm_kzalloc(&pdev->dev, sizeof(*as3722_rtc), GFP_KERNEL);
+	if (!as3722_rtc)
+		return -ENOMEM;
+
+	as3722_rtc->as3722 = as3722;
+	as3722_rtc->dev = &pdev->dev;
+	platform_set_drvdata(pdev, as3722_rtc);
+
+	as3722_get_rtc_dt_data(pdev, as3722_rtc);
+	enable_clk32k_out = as3722_rtc->enable_clk32k_out;
+
+	/* Enable the RTC to make sure it is running. */
+	ret = as3722_update_bits(as3722, AS3722_RTC_CONTROL_REG,
+				AS3722_RTC_ON, AS3722_RTC_ON);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "RTC_CONTROL reg update failed: %d\n", ret);
+		return ret;
+	}
+
+	val = AS3722_RTC_ON | AS3722_RTC_ALARM_WAKEUP_EN;
+	if (enable_clk32k_out)
+		val |= AS3722_RTC_CLK32K_OUT_EN;
+
+	ret = as3722_write(as3722, AS3722_RTC_CONTROL_REG, val);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "RTC_CONTROL reg write failed: %d\n", ret);
+		return ret;
+	}
+
+	device_init_wakeup(&pdev->dev, 1);
+
+	as3722_rtc->rtc = rtc_device_register("as3722", &pdev->dev,
+				&as3722_rtc_ops, THIS_MODULE);
+	if (IS_ERR(as3722_rtc->rtc)) {
+		ret = PTR_ERR(as3722_rtc->rtc);
+		dev_err(&pdev->dev, "RTC register failed: %d\n", ret);
+		return ret;
+	}
+
+	as3722_rtc->alarm_irq = platform_get_irq(pdev, 0);
+	dev_info(&pdev->dev, "RTC interrupt %d\n", as3722_rtc->alarm_irq);
+
+	ret = request_threaded_irq(as3722_rtc->alarm_irq, NULL,
+			as3722_alarm_irq, IRQF_ONESHOT | IRQF_EARLY_RESUME,
+			"rtc-alarm", as3722_rtc);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
+				as3722_rtc->alarm_irq, ret);
+		goto scrub;
+	}
+	disable_irq(as3722_rtc->alarm_irq);
+	return 0;
+scrub:
+	rtc_device_unregister(as3722_rtc->rtc);
+	return ret;
+}
+
+static int as3722_rtc_remove(struct platform_device *pdev)
+{
+	struct as3722_rtc *as3722_rtc = platform_get_drvdata(pdev);
+
+	free_irq(as3722_rtc->alarm_irq, as3722_rtc);
+	rtc_device_unregister(as3722_rtc->rtc);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int as3722_rtc_suspend(struct device *dev)
+{
+	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(as3722_rtc->alarm_irq);
+
+	return 0;
+}
+
+static int as3722_rtc_resume(struct device *dev)
+{
+	struct as3722_rtc *as3722_rtc = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(as3722_rtc->alarm_irq);
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops as3722_rtc_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(as3722_rtc_suspend, as3722_rtc_resume)
+};
+
+static const struct of_device_id of_as3722_rtc_match[] = {
+	{ .compatible = "ams,as3722-rtc"},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, of_as3722_rtc_match);
+
+static struct platform_driver as3722_rtc_driver = {
+	.probe = as3722_rtc_probe,
+	.remove = as3722_rtc_remove,
+	.driver = {
+		.name = "as3722-rtc",
+		.pm = &as3722_rtc_pm_ops,
+		.of_match_table = of_as3722_rtc_match,
+	},
+};
+module_platform_driver(as3722_rtc_driver);
+
+MODULE_DESCRIPTION("RTC driver for AS3722 PMICs");
+MODULE_ALIAS("platform:as3722-rtc");
+MODULE_AUTHOR("Florian Lobmaier <florian.lobmaier@ams.com>");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
+MODULE_LICENSE("GPL");