[PATCH 0/4] Make PL031 interrupt optional

[PATCH 0/4] Make PL031 interrupt optional

[Russell King - ARM Linux]

There are some boards out there which have a PL031 RTC, but its
interrupt is not wired up.  To support these, we need the PL031
to support the primecell without interrupts.

When no interrupt is present, there's little point exposing the
RTC's alarm capabilities, so we omit the alarm-related function
calls - the RTC merely becomes a source of time-of-day.

This patch series cleans pu the pl031 driver a little, and adds
support for this configuration.

 drivers/rtc/rtc-pl031.c | 48 +++++++++++++++++++++++++++---------------------
 1 file changed, 27 insertions(+), 21 deletions(-)

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

[PATCH 1/4] rtc: pl031: constify amba_ids

[Russell King]

The AMBA device IDs should be marked const.  Make that so.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/rtc/rtc-pl031.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
index e1687e19c59f..0d87b90b1903 100644
--- a/drivers/rtc/rtc-pl031.c
+++ b/drivers/rtc/rtc-pl031.c
@@ -446,7 +446,7 @@ static struct pl031_vendor_data stv2_pl031 = {
 	.irqflags = IRQF_SHARED | IRQF_COND_SUSPEND,
 };
 
-static struct amba_id pl031_ids[] = {
+static const struct amba_id pl031_ids[] = {
 	{
 		.id = 0x00041031,
 		.mask = 0x000fffff,
-- 
2.7.4

[PATCH 1/4] rtc: pl031: constify amba_ids

[Linus Walleij]

On Fri, Jul 21, 2017 at 1:18 AM, Russell King
<rmk+kernel@armlinux.org.uk> wrote:

> The AMBA device IDs should be marked const.  Make that so.
>
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

[PATCH 2/4] rtc: pl031: use devm_* for allocating memory and mapping resource

[Russell King]

Use the devm_* APIs for allocating memory and mapping the memory in
the probe function to relieve the driver from having to deal with
this in the cleanup paths.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/rtc/rtc-pl031.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
index 0d87b90b1903..5960fbd08b05 100644
--- a/drivers/rtc/rtc-pl031.c
+++ b/drivers/rtc/rtc-pl031.c
@@ -310,8 +310,6 @@ static int pl031_remove(struct amba_device *adev)
 	device_init_wakeup(&adev->dev, false);
 	free_irq(adev->irq[0], ldata);
 	rtc_device_unregister(ldata->rtc);
-	iounmap(ldata->base);
-	kfree(ldata);
 	amba_release_regions(adev);
 
 	return 0;
@@ -322,25 +320,26 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
 	int ret;
 	struct pl031_local *ldata;
 	struct pl031_vendor_data *vendor = id->data;
-	struct rtc_class_ops *ops = &vendor->ops;
+	struct rtc_class_ops *ops;
 	unsigned long time, data;
 
 	ret = amba_request_regions(adev, NULL);
 	if (ret)
 		goto err_req;
 
-	ldata = kzalloc(sizeof(struct pl031_local), GFP_KERNEL);
+	ldata = devm_kzalloc(&adev->dev, sizeof(struct pl031_local),
+			     GFP_KERNEL);
 	if (!ldata) {
 		ret = -ENOMEM;
 		goto out;
 	}
 	ldata->vendor = vendor;
 
-	ldata->base = ioremap(adev->res.start, resource_size(&adev->res));
-
+	ldata->base = devm_ioremap(&adev->dev, adev->res.start,
+				   resource_size(&adev->res));
 	if (!ldata->base) {
 		ret = -ENOMEM;
-		goto out_no_remap;
+		goto out;
 	}
 
 	amba_set_drvdata(adev, ldata);
@@ -378,7 +377,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
 					THIS_MODULE);
 	if (IS_ERR(ldata->rtc)) {
 		ret = PTR_ERR(ldata->rtc);
-		goto out_no_rtc;
+		goto out;
 	}
 
 	if (request_irq(adev->irq[0], pl031_interrupt,
@@ -391,10 +390,6 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
 
 out_no_irq:
 	rtc_device_unregister(ldata->rtc);
-out_no_rtc:
-	iounmap(ldata->base);
-out_no_remap:
-	kfree(ldata);
 out:
 	amba_release_regions(adev);
 err_req:
-- 
2.7.4

[PATCH 2/4] rtc: pl031: use devm_* for allocating memory and mapping resource

[Linus Walleij]

On Fri, Jul 21, 2017 at 1:18 AM, Russell King
<rmk+kernel@armlinux.org.uk> wrote:

> Use the devm_* APIs for allocating memory and mapping the memory in
> the probe function to relieve the driver from having to deal with
> this in the cleanup paths.
>
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

[PATCH 2/4] rtc: pl031: use devm_* for allocating memory and mapping resource

[Alexandre Belloni]

Hi Russell,

On 21/07/2017 at 00:18:31 +0100, Russell King wrote:
> Use the devm_* APIs for allocating memory and mapping the memory in
> the probe function to relieve the driver from having to deal with
> this in the cleanup paths.
> 
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
> ---
>  drivers/rtc/rtc-pl031.c | 19 +++++++------------
>  1 file changed, 7 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
> index 0d87b90b1903..5960fbd08b05 100644
> --- a/drivers/rtc/rtc-pl031.c
> +++ b/drivers/rtc/rtc-pl031.c
> @@ -310,8 +310,6 @@ static int pl031_remove(struct amba_device *adev)
>  	device_init_wakeup(&adev->dev, false);
>  	free_irq(adev->irq[0], ldata);
>  	rtc_device_unregister(ldata->rtc);
> -	iounmap(ldata->base);
> -	kfree(ldata);
>  	amba_release_regions(adev);
>  
>  	return 0;
> @@ -322,25 +320,26 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
>  	int ret;
>  	struct pl031_local *ldata;
>  	struct pl031_vendor_data *vendor = id->data;
> -	struct rtc_class_ops *ops = &vendor->ops;
> +	struct rtc_class_ops *ops;

This change should probably go in patch 3/4


-- 
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[PATCH 3/4] rtc: pl031: avoid exposing alarm if no interrupt

[Russell King]

If the RTC has no interrupt, there is little point in exposing the RTC
alarm capabilities, as it can't be used as a wakeup source nor can it
deliver an event to userspace.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/rtc/rtc-pl031.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
index 5960fbd08b05..64c77ec1b4ea 100644
--- a/drivers/rtc/rtc-pl031.c
+++ b/drivers/rtc/rtc-pl031.c
@@ -329,12 +329,14 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
 
 	ldata = devm_kzalloc(&adev->dev, sizeof(struct pl031_local),
 			     GFP_KERNEL);
-	if (!ldata) {
+	ops = devm_kmemdup(&adev->dev, &vendor->ops, sizeof(vendor->ops),
+			   GFP_KERNEL);
+	if (!ldata || !ops) {
 		ret = -ENOMEM;
 		goto out;
 	}
-	ldata->vendor = vendor;
 
+	ldata->vendor = vendor;
 	ldata->base = devm_ioremap(&adev->dev, adev->res.start,
 				   resource_size(&adev->res));
 	if (!ldata->base) {
@@ -372,6 +374,13 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
 		}
 	}
 
+	if (!adev->irq[0]) {
+		/* When there's no interrupt, no point in exposing the alarm */
+		ops->read_alarm = NULL;
+		ops->set_alarm = NULL;
+		ops->alarm_irq_enable = NULL;
+	}
+
 	device_init_wakeup(&adev->dev, true);
 	ldata->rtc = rtc_device_register("pl031", &adev->dev, ops,
 					THIS_MODULE);
-- 
2.7.4

[PATCH 3/4] rtc: pl031: avoid exposing alarm if no interrupt

[Linus Walleij]

On Fri, Jul 21, 2017 at 1:18 AM, Russell King
<rmk+kernel@armlinux.org.uk> wrote:

> If the RTC has no interrupt, there is little point in exposing the RTC
> alarm capabilities, as it can't be used as a wakeup source nor can it
> deliver an event to userspace.
>
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

This makes all kind of sense.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

[PATCH 4/4] rtc: pl031: make interrupt optional

[Russell King]

On some platforms, the interrupt for the PL031 is optional.  Avoid
trying to claim the interrupt if it's not specified.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/rtc/rtc-pl031.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
index 64c77ec1b4ea..82eb7da2c478 100644
--- a/drivers/rtc/rtc-pl031.c
+++ b/drivers/rtc/rtc-pl031.c
@@ -308,7 +308,8 @@ static int pl031_remove(struct amba_device *adev)
 
 	dev_pm_clear_wake_irq(&adev->dev);
 	device_init_wakeup(&adev->dev, false);
-	free_irq(adev->irq[0], ldata);
+	if (adev->irq[0])
+		free_irq(adev->irq[0], ldata);
 	rtc_device_unregister(ldata->rtc);
 	amba_release_regions(adev);
 
@@ -389,12 +390,13 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
 		goto out;
 	}
 
-	if (request_irq(adev->irq[0], pl031_interrupt,
-			vendor->irqflags, "rtc-pl031", ldata)) {
-		ret = -EIO;
-		goto out_no_irq;
+	if (adev->irq[0]) {
+		ret = request_irq(adev->irq[0], pl031_interrupt,
+				  vendor->irqflags, "rtc-pl031", ldata);
+		if (ret)
+			goto out_no_irq;
+		dev_pm_set_wake_irq(&adev->dev, adev->irq[0]);
 	}
-	dev_pm_set_wake_irq(&adev->dev, adev->irq[0]);
 	return 0;
 
 out_no_irq:
-- 
2.7.4

[PATCH 4/4] rtc: pl031: make interrupt optional

[Linus Walleij]

On Fri, Jul 21, 2017 at 1:18 AM, Russell King
<rmk+kernel@armlinux.org.uk> wrote:

> On some platforms, the interrupt for the PL031 is optional.  Avoid
> trying to claim the interrupt if it's not specified.
>
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij