[PATCH] rtc: snvs: add Freescale rtc-snvs driver

Thanks for looking at it, Stephen.

On Mon, Jul 02, 2012 at 12:07:00PM -0700, Stephen Boyd wrote:

On 07/02/12 09:09, Shawn Guo wrote:

quoted

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 08cbdb9..511ddcb 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig

@@ -1087,4 +1087,14 @@ config RTC_DRV_MXC
 	   This driver can also be built as a module, if so, the module
 	   will be called "rtc-mxc".
 
+config RTC_DRV_SNVS
+	tristate "Freescale SNVS RTC support"
+	depends on ARCH_MXC

If you want more build coverage you can depend on HAS_IOMEM and drop the
ARCH_MXC part.

Dropping ARCH_MXC sounds like a good idea.  But why do we need to
depend on HAS_IOMEM?  readl/writel are not always available?

I would add "depends on OF" though.

quoted

+	help
+	   If you say yes here you get support for the Freescale SNVS
+	   Low Power (LP) RTC module.
+

diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c
new file mode 100644
index 0000000..761c91f
--- /dev/null
+++ b/drivers/rtc/rtc-snvs.c

@@ -0,0 +1,350 @@
+/*
+ * Copyright (C) 2011-2012 Freescale Semiconductor, Inc.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/delay.h>

Is this include used?

No.  It should be removed.

quoted

+
+static struct rtc_class_ops snvs_rtc_ops = {

const?

Indeed.

quoted

+static irqreturn_t snvs_rtc_irq_handler(int irq, void *dev_id)
+{
+	struct device *dev = dev_id;
+	struct snvs_rtc_data *data = dev_get_drvdata(dev);

Why not just pass the svsns_rtc_data to request_irq() so you can cast
dev_id directly?

Because snvs_rtc_alarm_irq_enable(dev, 0) is being called in there
with dev as the first parameter.

quoted

+static int __devinit snvs_rtc_probe(struct platform_device *pdev)
+{
+	struct snvs_rtc_data *data;
+	struct resource *res;
+	int ret;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->ioaddr = devm_request_and_ioremap(&pdev->dev, res);
+	if (!data->ioaddr)
+		return -EADDRNOTAVAIL;
+
+	data->irq = platform_get_irq(pdev, 0);

What if this irq fails to exist?

The later devm_request_irq() call will report error then.

quoted

+static const struct of_device_id __devinitdata snvs_dt_ids[] = {

Is this supposed to be __devinitconst?

Right.

quoted

+	{ .compatible = "fsl,sec-v4.0-mon" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, snvs_dt_ids);

Surround this of_device table in #ifdef CONFIG_OF?

Maybe not.  I intend to have the driver OF only.

quoted

+
+static struct platform_driver snvs_rtc_driver = {
+	.driver = {
+		.name	= "snvs_rtc",
+		.owner	= THIS_MODULE,
+		.of_match_table = snvs_dt_ids,

.of_match_table = of_match_ptr(svns_dt_ids)

Ditto

quoted

+	},
+	.probe		= snvs_rtc_probe,
+	.remove		= __devexit_p(snvs_rtc_remove),
+	.suspend	= snvs_rtc_suspend,
+	.resume		= snvs_rtc_resume,

Can you use dev_pm_ops?

Ok.

-- 
Regards,
Shawn