diff mbox series

[v2,04/91] firmware: rpi: Only create clocks device if we don't have a node for it

Message ID b181d867cb9523e1877a3dfd258bafde2988024f.1587742492.git-series.maxime@cerno.tech (mailing list archive)
State New, archived
Headers show
Series drm/vc4: Support BCM2711 Display Pipeline | expand

Commit Message

Maxime Ripard April 24, 2020, 3:33 p.m. UTC
The firmware clocks driver was previously probed through a platform_device
created by the firmware driver.

Since we will now have a node for that clocks driver, we need to create the
device only in the case where there's no node for it already.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/firmware/raspberrypi.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

Comments

Nicolas Saenz Julienne April 27, 2020, 11:24 a.m. UTC | #1
Hi Maxime,

On Fri, 2020-04-24 at 17:33 +0200, Maxime Ripard wrote:
> The firmware clocks driver was previously probed through a platform_device
> created by the firmware driver.
> 
> Since we will now have a node for that clocks driver, we need to create the
> device only in the case where there's no node for it already.
> 
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> ---
>  drivers/firmware/raspberrypi.c | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberrypi.c
> index da26a584dca0..1874f41b007c 100644
> --- a/drivers/firmware/raspberrypi.c
> +++ b/drivers/firmware/raspberrypi.c
> @@ -210,6 +210,15 @@ rpi_register_hwmon_driver(struct device *dev, struct
> rpi_firmware *fw)
>  
>  static void rpi_register_clk_driver(struct device *dev)
>  {
> +	/*
> +	 * Earlier DTs don't have a node for the firmware clocks but
> +	 * rely on us creating a platform device by hand. If we do
> +	 * have a node for the firmware clocks, just bail out here.
> +	 */
> +	if (of_get_compatible_child(dev->of_node,
> +				    "raspberrypi,firmware-clocks"))
> +		return;
> +
>  	rpi_clk = platform_device_register_data(dev, "raspberrypi-clk",
>  						-1, NULL, 0);
>  }
> @@ -262,8 +271,12 @@ static int rpi_firmware_remove(struct platform_device
> *pdev)
>  
>  	platform_device_unregister(rpi_hwmon);
>  	rpi_hwmon = NULL;
> -	platform_device_unregister(rpi_clk);
> -	rpi_clk = NULL;
> +
> +	if (rpi_clk) {

rpi_clk, being a static global variable, will be zeroed by default. So, if you
don't register the platform device, rpi_clk is going to be NULL, which you're
allowed to feed platform_device_unregister(), so no need to be extra careful.

Regards,
Nicolas

> +		platform_device_unregister(rpi_clk);
> +		rpi_clk = NULL;
> +	}
> +
>  	mbox_free_channel(fw->chan);
>  
>  	return 0;
Maxime Ripard April 28, 2020, 1:50 p.m. UTC | #2
Hi Nicolas,

On Mon, Apr 27, 2020 at 01:24:14PM +0200, Nicolas Saenz Julienne wrote:
> Hi Maxime,
> 
> On Fri, 2020-04-24 at 17:33 +0200, Maxime Ripard wrote:
> > The firmware clocks driver was previously probed through a platform_device
> > created by the firmware driver.
> > 
> > Since we will now have a node for that clocks driver, we need to create the
> > device only in the case where there's no node for it already.
> > 
> > Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> > ---
> >  drivers/firmware/raspberrypi.c | 17 +++++++++++++++--
> >  1 file changed, 15 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberrypi.c
> > index da26a584dca0..1874f41b007c 100644
> > --- a/drivers/firmware/raspberrypi.c
> > +++ b/drivers/firmware/raspberrypi.c
> > @@ -210,6 +210,15 @@ rpi_register_hwmon_driver(struct device *dev, struct
> > rpi_firmware *fw)
> >  
> >  static void rpi_register_clk_driver(struct device *dev)
> >  {
> > +	/*
> > +	 * Earlier DTs don't have a node for the firmware clocks but
> > +	 * rely on us creating a platform device by hand. If we do
> > +	 * have a node for the firmware clocks, just bail out here.
> > +	 */
> > +	if (of_get_compatible_child(dev->of_node,
> > +				    "raspberrypi,firmware-clocks"))
> > +		return;
> > +
> >  	rpi_clk = platform_device_register_data(dev, "raspberrypi-clk",
> >  						-1, NULL, 0);
> >  }
> > @@ -262,8 +271,12 @@ static int rpi_firmware_remove(struct platform_device
> > *pdev)
> >  
> >  	platform_device_unregister(rpi_hwmon);
> >  	rpi_hwmon = NULL;
> > -	platform_device_unregister(rpi_clk);
> > -	rpi_clk = NULL;
> > +
> > +	if (rpi_clk) {
> 
> rpi_clk, being a static global variable, will be zeroed by default. So, if you
> don't register the platform device, rpi_clk is going to be NULL, which you're
> allowed to feed platform_device_unregister(), so no need to be extra careful.

Indeed, I'll fix that up.

Thanks!
Maxime
Nicolas Saenz Julienne April 30, 2020, 4:27 p.m. UTC | #3
On Fri, 2020-04-24 at 17:33 +0200, Maxime Ripard wrote:
> The firmware clocks driver was previously probed through a platform_device
> created by the firmware driver.
> 
> Since we will now have a node for that clocks driver, we need to create the
> device only in the case where there's no node for it already.
> 
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> ---
>  drivers/firmware/raspberrypi.c | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberrypi.c
> index da26a584dca0..1874f41b007c 100644
> --- a/drivers/firmware/raspberrypi.c
> +++ b/drivers/firmware/raspberrypi.c
> @@ -210,6 +210,15 @@ rpi_register_hwmon_driver(struct device *dev, struct
> rpi_firmware *fw)
>  
>  static void rpi_register_clk_driver(struct device *dev)
>  {
> +	/*
> +	 * Earlier DTs don't have a node for the firmware clocks but
> +	 * rely on us creating a platform device by hand. If we do
> +	 * have a node for the firmware clocks, just bail out here.
> +	 */
> +	if (of_get_compatible_child(dev->of_node,
> +				    "raspberrypi,firmware-clocks"))

In the case you find a compatible device node you have to decrement the
refcount of_get_compatible_child() increased before leaving.

Regards,
Nicolas
diff mbox series

Patch

diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberrypi.c
index da26a584dca0..1874f41b007c 100644
--- a/drivers/firmware/raspberrypi.c
+++ b/drivers/firmware/raspberrypi.c
@@ -210,6 +210,15 @@  rpi_register_hwmon_driver(struct device *dev, struct rpi_firmware *fw)
 
 static void rpi_register_clk_driver(struct device *dev)
 {
+	/*
+	 * Earlier DTs don't have a node for the firmware clocks but
+	 * rely on us creating a platform device by hand. If we do
+	 * have a node for the firmware clocks, just bail out here.
+	 */
+	if (of_get_compatible_child(dev->of_node,
+				    "raspberrypi,firmware-clocks"))
+		return;
+
 	rpi_clk = platform_device_register_data(dev, "raspberrypi-clk",
 						-1, NULL, 0);
 }
@@ -262,8 +271,12 @@  static int rpi_firmware_remove(struct platform_device *pdev)
 
 	platform_device_unregister(rpi_hwmon);
 	rpi_hwmon = NULL;
-	platform_device_unregister(rpi_clk);
-	rpi_clk = NULL;
+
+	if (rpi_clk) {
+		platform_device_unregister(rpi_clk);
+		rpi_clk = NULL;
+	}
+
 	mbox_free_channel(fw->chan);
 
 	return 0;