[5/5] platform: Make platform_bus device a platform device

Message ID 1406298233-27876-5-git-send-email-pawel.moll@arm.com
State New
Headers show

Commit Message

Pawel Moll July 25, 2014, 2:23 p.m.
... describing the root of the device tree, so one can write
a platform driver initializing the platform.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
---
 drivers/base/platform.c         | 20 ++++++++++++++------
 include/linux/platform_device.h |  2 +-
 2 files changed, 15 insertions(+), 7 deletions(-)

Comments

Greg KH July 26, 2014, 8:12 p.m. | #1
On Fri, Jul 25, 2014 at 03:23:53PM +0100, Pawel Moll wrote:
> ... describing the root of the device tree, so one can write
> a platform driver initializing the platform.

Wait, what do you mean by "one can write a platform driver initializing
the platform"?  I don't understand your end goal here...

thanks,

greg k-h
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Greg KH July 26, 2014, 8:13 p.m. | #2
On Fri, Jul 25, 2014 at 03:23:53PM +0100, Pawel Moll wrote:
> ... describing the root of the device tree, so one can write
> a platform driver initializing the platform.
> 
> Signed-off-by: Pawel Moll <pawel.moll@arm.com>
> ---
>  drivers/base/platform.c         | 20 ++++++++++++++------
>  include/linux/platform_device.h |  2 +-
>  2 files changed, 15 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index eee48c4..9caffa7 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -30,8 +30,8 @@
>  /* For automatically allocated device IDs */
>  static DEFINE_IDA(platform_devid_ida);
>  
> -struct device platform_bus = {
> -	.init_name	= "platform",
> +struct platform_device platform_bus = {
> +	.name	= "platform",
>  };
>  EXPORT_SYMBOL_GPL(platform_bus);
>  
> @@ -300,7 +300,7 @@ int platform_device_add(struct platform_device *pdev)
>  		return -EINVAL;
>  
>  	if (!pdev->dev.parent)
> -		pdev->dev.parent = &platform_bus;
> +		pdev->dev.parent = &platform_bus.dev;
>  
>  	pdev->dev.bus = &platform_bus_type;
>  
> @@ -946,12 +946,20 @@ int __init platform_bus_init(void)
>  
>  	early_platform_cleanup();
>  
> -	error = device_register(&platform_bus);
> +	dev_set_name(&platform_bus.dev, "%s", platform_bus.name);
> +	error = device_register(&platform_bus.dev);
>  	if (error)
>  		return error;
>  	error =  bus_register(&platform_bus_type);
> -	if (error)
> -		device_unregister(&platform_bus);
> +	if (!error) {
> +#ifdef CONFIG_OF
> +		platform_bus.dev.of_node = of_allnodes;
> +#endif

Why are you doing this?  The original code didn't do it and all was
fine, right?  What changes here?

thanks,

greg k-h
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Pawel Moll Aug. 1, 2014, 5:21 p.m. | #3
On Sat, 2014-07-26 at 21:13 +0100, Greg Kroah-Hartman wrote:
> > @@ -946,12 +946,20 @@ int __init platform_bus_init(void)
> >  
> >  	early_platform_cleanup();
> >  
> > -	error = device_register(&platform_bus);
> > +	dev_set_name(&platform_bus.dev, "%s", platform_bus.name);
> > +	error = device_register(&platform_bus.dev);
> >  	if (error)
> >  		return error;
> >  	error =  bus_register(&platform_bus_type);
> > -	if (error)
> > -		device_unregister(&platform_bus);
> > +	if (!error) {
> > +#ifdef CONFIG_OF
> > +		platform_bus.dev.of_node = of_allnodes;
> > +#endif
> 
> Why are you doing this?  The original code didn't do it and all was
> fine, right?  What changes here?

You mean the #ifdef? It wasn't there, but Olof figured out that it
breaks !CONFIG_OF builds:

http://article.gmane.org/gmane.linux.ports.tegra/18473

as of_allnodes is only defined when CONFIG_OF. I had a choice of
#ifdefing the assignment above or providing a dummy symbol. The latter
doesn't seem sensibly, as there should be no other users for it (the
symbol).

Pawel

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Pawel Moll Aug. 1, 2014, 5:21 p.m. | #4
On Sat, 2014-07-26 at 21:12 +0100, Greg Kroah-Hartman wrote:
> On Fri, Jul 25, 2014 at 03:23:53PM +0100, Pawel Moll wrote:
> > ... describing the root of the device tree, so one can write
> > a platform driver initializing the platform.
> 
> Wait, what do you mean by "one can write a platform driver initializing
> the platform"?  I don't understand your end goal here...

Bad wording, sorry. The goal is to have a platform driver (as in
platform bus) that will initialize my platform (as in: board, machine,
hardware). My platform (as in: the board) will be represented by the
root platform bus device (as in: the bus ;-) with compatible value
matching the one passed in the device tree's root.

The tree:

8<----------------------------
/ {
	compatible = "my,board";
}
8<----------------------------

The driver:

8<----------------------------
static struct of_device_id my_board_match[] = {
        { .compatible = "my,board", },
        {},
};

static struct platform_driver my_board_driver = {
        .driver = {
                .name = "my_board",
                .owner = THIS_MODULE,
                .of_match_table = of_match_ptr(my_board_match),
        },
        .probe = my_board_probe,
        .remove = my_board_remove,
};
module_platform_driver(my_board_driver);
8<----------------------------

I'll work on better commit message for the next spin.

PaweĊ‚


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Patch hide | download patch | download mbox

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index eee48c4..9caffa7 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -30,8 +30,8 @@ 
 /* For automatically allocated device IDs */
 static DEFINE_IDA(platform_devid_ida);
 
-struct device platform_bus = {
-	.init_name	= "platform",
+struct platform_device platform_bus = {
+	.name	= "platform",
 };
 EXPORT_SYMBOL_GPL(platform_bus);
 
@@ -300,7 +300,7 @@  int platform_device_add(struct platform_device *pdev)
 		return -EINVAL;
 
 	if (!pdev->dev.parent)
-		pdev->dev.parent = &platform_bus;
+		pdev->dev.parent = &platform_bus.dev;
 
 	pdev->dev.bus = &platform_bus_type;
 
@@ -946,12 +946,20 @@  int __init platform_bus_init(void)
 
 	early_platform_cleanup();
 
-	error = device_register(&platform_bus);
+	dev_set_name(&platform_bus.dev, "%s", platform_bus.name);
+	error = device_register(&platform_bus.dev);
 	if (error)
 		return error;
 	error =  bus_register(&platform_bus_type);
-	if (error)
-		device_unregister(&platform_bus);
+	if (!error) {
+#ifdef CONFIG_OF
+		platform_bus.dev.of_node = of_allnodes;
+#endif
+		platform_bus.dev.bus = &platform_bus_type;
+		bus_add_device(&platform_bus.dev);
+	} else {
+		device_unregister(&platform_bus.dev);
+	}
 	return error;
 }
 
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 16f6654..a99032a 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -44,7 +44,7 @@  extern int platform_device_register(struct platform_device *);
 extern void platform_device_unregister(struct platform_device *);
 
 extern struct bus_type platform_bus_type;
-extern struct device platform_bus;
+extern struct platform_device platform_bus;
 
 extern void arch_setup_pdev_archdata(struct platform_device *);
 extern struct resource *platform_get_resource(struct platform_device *,