diff mbox

[RESENT,RTC] Add Freescale MC13783 RTC driver

Message ID 1257841967-6084-1-git-send-email-u.kleine-koenig@pengutronix.de
State Accepted, archived
Headers show

Commit Message

Uwe Kleine-König Nov. 10, 2009, 8:32 a.m. UTC
This driver provides support for the RTC part integrated into the
Freescale MC13783 PMIC and bases on patch created earlier by Sascha
Hauer.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-könig@pengutronix.de>
Acked-by: Valentin Longchamp <valentin.longchamp@epfl.ch>
Cc: Paul Gortmaker <p_gortmaker@yahoo.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: rtc-linux@googlegroups.com
---
 drivers/rtc/Kconfig       |    6 +
 drivers/rtc/Makefile      |    1 +
 drivers/rtc/rtc-mc13783.c |  262 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 269 insertions(+), 0 deletions(-)
 create mode 100644 drivers/rtc/rtc-mc13783.c

Comments

Alessandro Zummo Nov. 10, 2009, 9:30 a.m. UTC | #1
On Tue, 10 Nov 2009 09:32:47 +0100
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote:

> +	ret = mc13783_irq_request_nounmask(priv->mc13783, MC13783_IRQ_1HZ,
> +			mc13783_rtc_update_handler, DRIVER_NAME, priv);
> +	if (ret)
> +		goto err_update_irq_request;
> +
> +	mc13783_unlock(priv->mc13783);
> +
> +	priv->rtc = rtc_device_register(pdev->name,
> +			&pdev->dev, &mc13783_rtc_ops, THIS_MODULE);
> +

 isn't better to enable irqs after registration?
Uwe Kleine-König Nov. 10, 2009, 11:10 a.m. UTC | #2
On Tue, Nov 10, 2009 at 10:30:54AM +0100, Alessandro Zummo wrote:
> On Tue, 10 Nov 2009 09:32:47 +0100
> Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote:
> 
> > +	ret = mc13783_irq_request_nounmask(priv->mc13783, MC13783_IRQ_1HZ,
> > +			mc13783_rtc_update_handler, DRIVER_NAME, priv);
> > +	if (ret)
> > +		goto err_update_irq_request;
> > +
> > +	mc13783_unlock(priv->mc13783);
> > +
> > +	priv->rtc = rtc_device_register(pdev->name,
> > +			&pdev->dev, &mc13783_rtc_ops, THIS_MODULE);
> > +
> 
>  isn't better to enable irqs after registration.
IMHO it doesn't make a difference for the 1HZ irq, still more as it
remains masked.  The reset irq should be requested before registration.

Best regards
Uwe
Uwe Kleine-König Nov. 22, 2009, 9:49 p.m. UTC | #3
Hi Alessandro,

On Tue, Nov 10, 2009 at 12:10:01PM +0100, Uwe Kleine-König wrote:
> On Tue, Nov 10, 2009 at 10:30:54AM +0100, Alessandro Zummo wrote:
> > On Tue, 10 Nov 2009 09:32:47 +0100
> > Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote:
> > 
> > > +	ret = mc13783_irq_request_nounmask(priv->mc13783, MC13783_IRQ_1HZ,
> > > +			mc13783_rtc_update_handler, DRIVER_NAME, priv);
> > > +	if (ret)
> > > +		goto err_update_irq_request;
> > > +
> > > +	mc13783_unlock(priv->mc13783);
> > > +
> > > +	priv->rtc = rtc_device_register(pdev->name,
> > > +			&pdev->dev, &mc13783_rtc_ops, THIS_MODULE);
> > > +
> > 
> >  isn't better to enable irqs after registration.
> IMHO it doesn't make a difference for the 1HZ irq, still more as it
> remains masked.  The reset irq should be requested before registration.
I thought again about the 1HZ irq.  There are two different things to
consider:

 - After rtc_device_register the .update_irq_enable callback could be
   called at once.  At that time the update irq should already be
   registered.  So register irq before rtc_device.
 - The update irq handler calls rtc_update_irq(struct rtc_device *,
   ...) so the rtc_device should already be complete.  That is, register
   before the irq can trigger.

To satisfy both you need to make sure the irq is registered before
registration but masked (either at controller level as in my patch or at
device level (which should be the usual thing but there is no knob in
the mc13783's rtc for that)).

Will you take my patch?

Best regards
Uwe
diff mbox

Patch

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 3c20dae..7fa8db3 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -827,4 +827,10 @@  config RTC_DRV_PCAP
 	  If you say Y here you will get support for the RTC found on
 	  the PCAP2 ASIC used on some Motorola phones.
 
+config RTC_DRV_MC13783
+	depends on MFD_MC13783
+	tristate "Freescale MC13783 RTC"
+	help
+	  This enables support for the Freescale MC13783 PMIC RTC
+
 endif # RTC_CLASS
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index aa3fbd5..f4d01ba 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -52,6 +52,7 @@  obj-$(CONFIG_RTC_DRV_M48T86)	+= rtc-m48t86.o
 obj-$(CONFIG_RTC_MXC)		+= rtc-mxc.o
 obj-$(CONFIG_RTC_DRV_MAX6900)	+= rtc-max6900.o
 obj-$(CONFIG_RTC_DRV_MAX6902)	+= rtc-max6902.o
+obj-$(CONFIG_RTC_DRV_MC13783)	+= rtc-mc13783.o
 obj-$(CONFIG_RTC_DRV_MV)	+= rtc-mv.o
 obj-$(CONFIG_RTC_DRV_OMAP)	+= rtc-omap.o
 obj-$(CONFIG_RTC_DRV_PCAP)	+= rtc-pcap.o
diff --git a/drivers/rtc/rtc-mc13783.c b/drivers/rtc/rtc-mc13783.c
new file mode 100644
index 0000000..850f983
--- /dev/null
+++ b/drivers/rtc/rtc-mc13783.c
@@ -0,0 +1,262 @@ 
+/*
+ * Real Time Clock driver for Freescale MC13783 PMIC
+ *
+ * (C) 2009 Sascha Hauer, Pengutronix
+ * (C) 2009 Uwe Kleine-Koenig, Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/mfd/mc13783.h>
+#include <linux/platform_device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rtc.h>
+
+#define DRIVER_NAME "mc13783-rtc"
+
+#define MC13783_RTCTOD	20
+#define MC13783_RTCTODA	21
+#define MC13783_RTCDAY	22
+#define MC13783_RTCDAYA	23
+
+struct mc13783_rtc {
+	struct rtc_device *rtc;
+	struct mc13783 *mc13783;
+	int valid;
+};
+
+static int mc13783_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct mc13783_rtc *priv = dev_get_drvdata(dev);
+	unsigned int seconds, days1, days2;
+	unsigned long s1970;
+	int ret;
+
+	mc13783_lock(priv->mc13783);
+
+	if (!priv->valid) {
+		ret = -ENODATA;
+		goto out;
+	}
+
+	ret = mc13783_reg_read(priv->mc13783, MC13783_RTCDAY, &days1);
+	if (unlikely(ret))
+		goto out;
+
+	ret = mc13783_reg_read(priv->mc13783, MC13783_RTCTOD, &seconds);
+	if (unlikely(ret))
+		goto out;
+
+	ret = mc13783_reg_read(priv->mc13783, MC13783_RTCDAY, &days2);
+out:
+	mc13783_unlock(priv->mc13783);
+
+	if (ret)
+		return ret;
+
+	if (days2 == days1 + 1) {
+		if (seconds >= 86400 / 2)
+			days2 = days1;
+		else
+			days1 = days2;
+	}
+
+	if (days1 != days2)
+		return -EIO;
+
+	s1970 = days1 * 86400 + seconds;
+
+	rtc_time_to_tm(s1970, tm);
+
+	return rtc_valid_tm(tm);
+}
+
+static int mc13783_rtc_set_mmss(struct device *dev, unsigned long secs)
+{
+	struct mc13783_rtc *priv = dev_get_drvdata(dev);
+	unsigned int seconds, days;
+	int ret;
+
+	seconds = secs % 86400;
+	days = secs / 86400;
+
+	mc13783_lock(priv->mc13783);
+
+	/*
+	 * first write seconds=0 to prevent a day switch between writing days
+	 * and seconds below
+	 */
+	ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTOD, 0);
+	if (unlikely(ret))
+		goto out;
+
+	ret = mc13783_reg_write(priv->mc13783, MC13783_RTCDAY, days);
+	if (unlikely(ret))
+		goto out;
+
+	ret = mc13783_reg_write(priv->mc13783, MC13783_RTCTOD, seconds);
+	if (unlikely(ret))
+		goto out;
+
+	ret = mc13783_ackirq(priv->mc13783, MC13783_IRQ_RTCRST);
+	if (unlikely(ret))
+		goto out;
+
+	ret = mc13783_unmask(priv->mc13783, MC13783_IRQ_RTCRST);
+out:
+	priv->valid = !ret;
+
+	mc13783_unlock(priv->mc13783);
+
+	return ret;
+}
+
+static irqreturn_t mc13783_rtc_update_handler(int irq, void *dev)
+{
+	struct mc13783_rtc *priv = dev;
+	struct mc13783 *mc13783 = priv->mc13783;
+
+	dev_dbg(&priv->rtc->dev, "1HZ\n");
+
+	rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_UF);
+
+	mc13783_ackirq(mc13783, irq);
+
+	return IRQ_HANDLED;
+}
+
+static int mc13783_rtc_update_irq_enable(struct device *dev,
+		unsigned int enabled)
+{
+	struct mc13783_rtc *priv = dev_get_drvdata(dev);
+	int ret = -ENODATA;
+
+	mc13783_lock(priv->mc13783);
+	if (!priv->valid)
+		goto out;
+
+	ret = (enabled ? mc13783_unmask : mc13783_mask)(priv->mc13783,
+			MC13783_IRQ_1HZ);
+out:
+	mc13783_unlock(priv->mc13783);
+
+	return ret;
+}
+
+static const struct rtc_class_ops mc13783_rtc_ops = {
+	.read_time = mc13783_rtc_read_time,
+	.set_mmss = mc13783_rtc_set_mmss,
+	.update_irq_enable = mc13783_rtc_update_irq_enable,
+};
+
+static irqreturn_t mc13783_rtc_reset_handler(int irq, void *dev)
+{
+	struct mc13783_rtc *priv = dev;
+	struct mc13783 *mc13783 = priv->mc13783;
+
+	dev_dbg(&priv->rtc->dev, "RTCRST\n");
+	priv->valid = 0;
+
+	mc13783_mask(mc13783, irq);
+
+	return IRQ_HANDLED;
+}
+
+static int __devinit mc13783_rtc_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct mc13783_rtc *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->mc13783 = dev_get_drvdata(pdev->dev.parent);
+	platform_set_drvdata(pdev, priv);
+
+	priv->valid = 1;
+
+	mc13783_lock(priv->mc13783);
+
+	ret = mc13783_irq_request(priv->mc13783, MC13783_IRQ_RTCRST,
+			mc13783_rtc_reset_handler, DRIVER_NAME, priv);
+	if (ret)
+		goto err_reset_irq_request;
+
+	ret = mc13783_irq_request_nounmask(priv->mc13783, MC13783_IRQ_1HZ,
+			mc13783_rtc_update_handler, DRIVER_NAME, priv);
+	if (ret)
+		goto err_update_irq_request;
+
+	mc13783_unlock(priv->mc13783);
+
+	priv->rtc = rtc_device_register(pdev->name,
+			&pdev->dev, &mc13783_rtc_ops, THIS_MODULE);
+
+	if (IS_ERR(priv->rtc)) {
+		ret = PTR_ERR(priv->rtc);
+
+		mc13783_lock(priv->mc13783);
+
+		mc13783_irq_free(priv->mc13783, MC13783_IRQ_1HZ, priv);
+err_update_irq_request:
+
+		mc13783_irq_free(priv->mc13783, MC13783_IRQ_RTCRST, priv);
+err_reset_irq_request:
+
+		mc13783_unlock(priv->mc13783);
+
+		platform_set_drvdata(pdev, NULL);
+		kfree(priv);
+	}
+
+	return ret;
+}
+
+static int __devexit mc13783_rtc_remove(struct platform_device *pdev)
+{
+	struct mc13783_rtc *priv = platform_get_drvdata(pdev);
+
+	rtc_device_unregister(priv->rtc);
+
+	mc13783_lock(priv->mc13783);
+
+	mc13783_irq_free(priv->mc13783, MC13783_IRQ_1HZ, priv);
+	mc13783_irq_free(priv->mc13783, MC13783_IRQ_RTCRST, priv);
+
+	mc13783_unlock(priv->mc13783);
+
+	platform_set_drvdata(pdev, NULL);
+
+	kfree(priv);
+
+	return 0;
+}
+
+static struct platform_driver mc13783_rtc_driver = {
+	.remove = __devexit_p(mc13783_rtc_remove),
+	.driver = {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init mc13783_rtc_init(void)
+{
+	return platform_driver_probe(&mc13783_rtc_driver, &mc13783_rtc_probe);
+}
+module_init(mc13783_rtc_init);
+
+static void __exit mc13783_rtc_exit(void)
+{
+	platform_driver_unregister(&mc13783_rtc_driver);
+}
+module_exit(mc13783_rtc_exit);
+
+MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
+MODULE_DESCRIPTION("RTC driver for Freescale MC13783 PMIC");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);