[PATCH] powerpc: Specify GPIO number base for controller in DT

[PATCH] powerpc: Specify GPIO number base for controller in DT

[Wolfgang Ocker]

The GPIOLIB allows the specification of a base gpio number for a
controller. That is not possible using OF. Instead, free gpio numbers
are assigned.

In order to allow static, predefined gpio numbers, a base property in
the gpio controller node specifies the first gpio number.

Signed-off-by: Wolfgang Ocker <weo@reccoware.de>
---

--- linux-2.6.27-rc7/drivers/of/gpio.c.of_gpiospecbase	2008-09-22 00:29:55.000000000 +0200
+++ linux-2.6.27-rc7/drivers/of/gpio.c	2008-09-29 13:50:28.000000000 +0200
@@ -164,6 +164,8 @@
 	int ret = -ENOMEM;
 	struct of_gpio_chip *of_gc = &mm_gc->of_gc;
 	struct gpio_chip *gc = &of_gc->gc;
+	const int *basep;
+	int baselen;
 
 	gc->label = kstrdup(np->full_name, GFP_KERNEL);
 	if (!gc->label)
@@ -173,7 +175,11 @@
 	if (!mm_gc->regs)
 		goto err1;
 
-	gc->base = -1;
+	basep = of_get_property(np, "base", &baselen);
+	if (!basep || baselen != sizeof(*basep))
+		gc->base = -1;
+	else
+		gc->base = *basep;
 
 	if (!of_gc->xlate)
 		of_gc->xlate = of_gpio_simple_xlate;
--- linux-2.6.27-rc7/Documentation/powerpc/booting-without-of.txt.spi_gpio_doc	2008-09-29 14:14:08.000000000 +0200
+++ linux-2.6.27-rc7/Documentation/powerpc/booting-without-of.txt	2008-09-29 14:24:26.000000000 +0200
@@ -2586,6 +2588,7 @@
 		#gpio-cells = <2>;
 		compatible = "fsl,qe-pario-bank-a", "fsl,qe-pario-bank";
 		reg = <0x1400 0x18>;
+		base = < 0x20 >;
 		gpio-controller;
 	};
 

Re: [PATCH] powerpc: Specify GPIO number base for controller in DT

[Kumar Gala]

On Oct 23, 2008, at 7:27 AM, Wolfgang Ocker wrote:

> The GPIOLIB allows the specification of a base gpio number for a
> controller. That is not possible using OF. Instead, free gpio numbers
> are assigned.
>
> In order to allow static, predefined gpio numbers, a base property in
> the gpio controller node specifies the first gpio number.
>
> Signed-off-by: Wolfgang Ocker <weo@reccoware.de>
> ---
>
> --- linux-2.6.27-rc7/drivers/of/gpio.c.of_gpiospecbase	2008-09-22  
> 00:29:55.000000000 +0200
> +++ linux-2.6.27-rc7/drivers/of/gpio.c	2008-09-29 13:50:28.000000000  
> +0200
> @@ -164,6 +164,8 @@
> 	int ret = -ENOMEM;
> 	struct of_gpio_chip *of_gc = &mm_gc->of_gc;
> 	struct gpio_chip *gc = &of_gc->gc;
> +	const int *basep;
> +	int baselen;
>
> 	gc->label = kstrdup(np->full_name, GFP_KERNEL);
> 	if (!gc->label)
> @@ -173,7 +175,11 @@
> 	if (!mm_gc->regs)
> 		goto err1;
>
> -	gc->base = -1;
> +	basep = of_get_property(np, "base", &baselen);
> +	if (!basep || baselen != sizeof(*basep))
> +		gc->base = -1;
> +	else
> +		gc->base = *basep;
>
> 	if (!of_gc->xlate)
> 		of_gc->xlate = of_gpio_simple_xlate;
> --- linux-2.6.27-rc7/Documentation/powerpc/booting-without- 
> of.txt.spi_gpio_doc	2008-09-29 14:14:08.000000000 +0200
> +++ linux-2.6.27-rc7/Documentation/powerpc/booting-without-of.txt	 
> 2008-09-29 14:24:26.000000000 +0200
> @@ -2586,6 +2588,7 @@
> 		#gpio-cells = <2>;
> 		compatible = "fsl,qe-pario-bank-a", "fsl,qe-pario-bank";
> 		reg = <0x1400 0x18>;
> +		base = < 0x20 >;
> 		gpio-controller;
> 	};

We need the define what base is somewhere

- k

[PATCH v2] powerpc: Specify GPIO number base for controller in DT

[Wolfgang Ocker]

The GPIOLIB allows the specification of a base gpio number for a
controller. That is not possible using OF. Instead, free gpio numbers
are assigned.

In order to allow static, predefined gpio numbers, a base property in
the gpio controller node specifies the first gpio number.

v2: added description of base property in doc 

Signed-off-by: Wolfgang Ocker <weo@reccoware.de>
---

--- linux-2.6.27.2/drivers/of/gpio.c.of_gpiospecbase	2008-10-18 19:57:22.000000000 +0200
+++ linux-2.6.27.2/drivers/of/gpio.c	2008-10-23 10:55:19.000000000 +0200
@@ -164,6 +164,8 @@
 	int ret = -ENOMEM;
 	struct of_gpio_chip *of_gc = &mm_gc->of_gc;
 	struct gpio_chip *gc = &of_gc->gc;
+	const int *basep;
+	int baselen;
 
 	gc->label = kstrdup(np->full_name, GFP_KERNEL);
 	if (!gc->label)
@@ -173,7 +175,11 @@
 	if (!mm_gc->regs)
 		goto err1;
 
-	gc->base = -1;
+	basep = of_get_property(np, "base", &baselen);
+	if (!basep || baselen != sizeof(*basep))
+		gc->base = -1;
+	else
+		gc->base = *basep;
 
 	if (!of_gc->xlate)
 		of_gc->xlate = of_gpio_simple_xlate;
--- linux-2.6.27.2/Documentation/powerpc/booting-without-of.txt.of_gpiospecbase	2008-10-18 19:57:22.000000000 +0200
+++ linux-2.6.27.2/Documentation/powerpc/booting-without-of.txt	2008-10-23 16:23:07.000000000 +0200
@@ -2580,12 +2582,17 @@
 Every GPIO controller node must have #gpio-cells property defined,
 this information will be used to translate gpio-specifiers.
 
+Optional properties:
+	base: first GPIO number handled by this controller; default is -1,
+		meaning dynamic ID allocation
+
 Example of two SOC GPIO banks defined as gpio-controller nodes:
 
 	qe_pio_a: gpio-controller@1400 {
 		#gpio-cells = <2>;
 		compatible = "fsl,qe-pario-bank-a", "fsl,qe-pario-bank";
 		reg = <0x1400 0x18>;
+		base = < 0x20 >;
 		gpio-controller;
 	};
 

Re: [PATCH v2] powerpc: Specify GPIO number base for controller in DT

[Kumar Gala]

On Oct 23, 2008, at 9:30 AM, Wolfgang Ocker wrote:

> --- linux-2.6.27.2/Documentation/powerpc/booting-without- 
> of.txt.of_gpiospecbase	2008-10-18 19:57:22.000000000 +0200
> +++ linux-2.6.27.2/Documentation/powerpc/booting-without-of.txt	 
> 2008-10-23 16:23:07.000000000 +0200
> @@ -2580,12 +2582,17 @@
> Every GPIO controller node must have #gpio-cells property defined,
> this information will be used to translate gpio-specifiers.
>
> +Optional properties:
> +	base: first GPIO number handled by this controller; default is -1,
> +		meaning dynamic ID allocation

"default -1" doesn't make any sense.  I assume you mean if the  
property doesn't it exist the behavior is "dynamic ID allocation"

>
> +
> Example of two SOC GPIO banks defined as gpio-controller nodes:
>
> 	qe_pio_a: gpio-controller@1400 {
> 		#gpio-cells = <2>;
> 		compatible = "fsl,qe-pario-bank-a", "fsl,qe-pario-bank";
> 		reg = <0x1400 0x18>;
> +		base = < 0x20 >;
> 		gpio-controller;
> 	};
>

Re: [PATCH v3] powerpc: Specify GPIO number base for controller in DT

[Wolfgang Ocker]

The GPIOLIB allows the specification of a base gpio number for a
controller. That is not possible using OF. Instead, free gpio numbers
are assigned.

In order to allow static, predefined gpio numbers, a base property in
the gpio controller node specifies the first gpio number.

v2, v3: added/improved description of base property in doc 

Signed-off-by: Wolfgang Ocker <weo@reccoware.de>
---

--- linux-2.6.27.2/drivers/of/gpio.c.of_gpiospecbase	2008-10-18 19:57:22.000000000 +0200
+++ linux-2.6.27.2/drivers/of/gpio.c	2008-10-23 10:55:19.000000000 +0200
@@ -164,6 +164,8 @@
 	int ret = -ENOMEM;
 	struct of_gpio_chip *of_gc = &mm_gc->of_gc;
 	struct gpio_chip *gc = &of_gc->gc;
+	const int *basep;
+	int baselen;
 
 	gc->label = kstrdup(np->full_name, GFP_KERNEL);
 	if (!gc->label)
@@ -173,7 +175,11 @@
 	if (!mm_gc->regs)
 		goto err1;
 
-	gc->base = -1;
+	basep = of_get_property(np, "base", &baselen);
+	if (!basep || baselen != sizeof(*basep))
+		gc->base = -1;
+	else
+		gc->base = *basep;
 
 	if (!of_gc->xlate)
 		of_gc->xlate = of_gpio_simple_xlate;
--- linux-2.6.27.2/Documentation/powerpc/booting-without-of.txt.of_gpiospecbase	2008-10-18 19:57:22.000000000 +0200
+++ linux-2.6.27.2/Documentation/powerpc/booting-without-of.txt	2008-10-23 16:45:06.000000000 +0200
@@ -2580,12 +2582,17 @@
 Every GPIO controller node must have #gpio-cells property defined,
 this information will be used to translate gpio-specifiers.
 
+Optional properties:
+	base: first GPIO number handled by this controller; if the property
+		does not exist, the first GPIO number is allocated dynamicly
+
 Example of two SOC GPIO banks defined as gpio-controller nodes:
 
 	qe_pio_a: gpio-controller@1400 {
 		#gpio-cells = <2>;
 		compatible = "fsl,qe-pario-bank-a", "fsl,qe-pario-bank";
 		reg = <0x1400 0x18>;
+		base = < 0x20 >;
 		gpio-controller;
 	};
 

Re: [PATCH v3] powerpc: Specify GPIO number base for controller in DT

[Stefan Roese]

On Thursday 23 October 2008, Wolfgang Ocker wrote:
> The GPIOLIB allows the specification of a base gpio number for a
> controller. That is not possible using OF. Instead, free gpio numbers
> are assigned.
>
> In order to allow static, predefined gpio numbers, a base property in
> the gpio controller node specifies the first gpio number.
>
> v2, v3: added/improved description of base property in doc

These version descriptions are better placed below the "---" line. And you 
should remove the "Re: " from the subject line. Other than this:

Acked-by: Stefan Roese <sr@denx.de>

> Signed-off-by: Wolfgang Ocker <weo@reccoware.de>
> ---

Best regards,
Stefan

Re: [PATCH] powerpc: Specify GPIO number base for controller in DT

[Matt Sealey]

Kumar Gala wrote:
> 
> On Oct 23, 2008, at 7:27 AM, Wolfgang Ocker wrote:
> 
>> The GPIOLIB allows the specification of a base gpio number for a
>> controller. That is not possible using OF. Instead, free gpio numbers
>> are assigned.
>>
>> In order to allow static, predefined gpio numbers, a base property in
>> the gpio controller node specifies the first gpio number.

See my latest mail.

I don't think it's enough to say which pin the GPIOs exposed 
start at; you need some sort of mask, or array of applicable 
GPIOs so that GPIOLIB can check which perhaps 3 pins out of a 
possible 32 are allocated to a controller and usable (these 
may be pin 5, pin 9 and pin 20, so a "base" of pin 5 would be 
outrageously inadequate).

-- 
Matt Sealey <matt@genesi-usa.com>
Genesi, Manager, Developer Relations

Re: [PATCH] powerpc: Specify GPIO number base for controller in DT

[Wolfgang Ocker]

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On Thu, 2008-10-23 at 16:35 -0500, Matt Sealey wrote:
> > On Oct 23, 2008, at 7:27 AM, Wolfgang Ocker wrote: 
> >> The GPIOLIB allows the specification of a base gpio number for a
> >> controller. That is not possible using OF. Instead, free gpio numbers
> >> are assigned.
> >>
> >> In order to allow static, predefined gpio numbers, a base property in
> >> the gpio controller node specifies the first gpio number.
> 
> See my latest mail.
> 
> I don't think it's enough to say which pin the GPIOs exposed 
> start at; you need some sort of mask, or array of applicable 
> GPIOs so that GPIOLIB can check which perhaps 3 pins out of a 
> possible 32 are allocated to a controller and usable (these 
> may be pin 5, pin 9 and pin 20, so a "base" of pin 5 would be 
> outrageously inadequate).

I'm not sure what you mean. That "base" is used in gpiochip_add() when
registering the gpio controller. There is no magic with a mask or so.

What do I miss?

Thanks,
Wolfgang

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Re: [PATCH] powerpc: Specify GPIO number base for controller in DT

[Anton Vorontsov]

On Thu, Oct 23, 2008 at 02:27:30PM +0200, Wolfgang Ocker wrote:
> The GPIOLIB allows the specification of a base gpio number for a
> controller. That is not possible using OF. Instead, free gpio numbers
> are assigned.
> 
> In order to allow static, predefined gpio numbers, a base property in
> the gpio controller node specifies the first gpio number.
> 
> Signed-off-by: Wolfgang Ocker <weo@reccoware.de>

[...]
> --- linux-2.6.27-rc7/Documentation/powerpc/booting-without-of.txt.spi_gpio_doc	2008-09-29 14:14:08.000000000 +0200
> +++ linux-2.6.27-rc7/Documentation/powerpc/booting-without-of.txt	2008-09-29 14:24:26.000000000 +0200
> @@ -2586,6 +2588,7 @@
>  		#gpio-cells = <2>;
>  		compatible = "fsl,qe-pario-bank-a", "fsl,qe-pario-bank";
>  		reg = <0x1400 0x18>;
> +		base = < 0x20 >;

The base has nothing to do with the hardware description, thus
device tree should not include it. Why exactly you need this?
I'm sure there is another way to solve the problem (whatever it
is).

-- 
Anton Vorontsov
email: cbouatmailru@gmail.com
irc://irc.freenode.net/bd2

Re: [PATCH v3] powerpc: Specify GPIO number base for controller in DT

[Anton Vorontsov]

On Thu, Oct 23, 2008 at 08:13:00PM +0200, Stefan Roese wrote:
> On Thursday 23 October 2008, Wolfgang Ocker wrote:
> > The GPIOLIB allows the specification of a base gpio number for a
> > controller. That is not possible using OF. Instead, free gpio numbers
> > are assigned.
> >
> > In order to allow static, predefined gpio numbers, a base property in
> > the gpio controller node specifies the first gpio number.
> >
> > v2, v3: added/improved description of base property in doc
> 
> These version descriptions are better placed below the "---" line. And you 
> should remove the "Re: " from the subject line. Other than this:
> 
> Acked-by: Stefan Roese <sr@denx.de>

Please-defer-this-patch-by: Anton Vorontsov <avorontsov@ru.mvista.com>

Wolfgang, Stefan, see this comment:

http://ozlabs.org/pipermail/linuxppc-dev/2008-October/064505.html

..just tell me what are you trying to solve.

Thanks,

-- 
Anton Vorontsov
email: cbouatmailru@gmail.com
irc://irc.freenode.net/bd2

Re: [PATCH v3] powerpc: Specify GPIO number base for controller in DT

[Grant Likely]

On Fri, Oct 24, 2008 at 10:54 AM, Anton Vorontsov
<avorontsov@ru.mvista.com> wrote:
> On Thu, Oct 23, 2008 at 08:13:00PM +0200, Stefan Roese wrote:
>> On Thursday 23 October 2008, Wolfgang Ocker wrote:
>> > The GPIOLIB allows the specification of a base gpio number for a
>> > controller. That is not possible using OF. Instead, free gpio numbers
>> > are assigned.
>> >
>> > In order to allow static, predefined gpio numbers, a base property in
>> > the gpio controller node specifies the first gpio number.
>> >
>> > v2, v3: added/improved description of base property in doc
>>
>> These version descriptions are better placed below the "---" line. And you
>> should remove the "Re: " from the subject line. Other than this:
>>
>> Acked-by: Stefan Roese <sr@denx.de>
>
> Please-defer-this-patch-by: Anton Vorontsov <avorontsov@ru.mvista.com>
>
> Wolfgang, Stefan, see this comment:
>
> http://ozlabs.org/pipermail/linuxppc-dev/2008-October/064505.html
>
> ..just tell me what are you trying to solve.

Yeah, I don't like this patch either.  GPIO numbering is a Linux
internal detail and has no bearing on the hardware description.  If
you need to know what a particular gpio number is then it should be
resolved by finding the device tree node; not by trying to fix a GPIO
controller to a particular number.

g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

Re: [PATCH v3] powerpc: Specify GPIO number base for controller in DT

[Wolfgang Ocker]

On Fri, 2008-10-24 at 11:12 -0600, Grant Likely wrote:
> On Fri, Oct 24, 2008 at 10:54 AM, Anton Vorontsov
> <avorontsov@ru.mvista.com> wrote:
> > On Thu, Oct 23, 2008 at 08:13:00PM +0200, Stefan Roese wrote:
> >> On Thursday 23 October 2008, Wolfgang Ocker wrote:
> >> > The GPIOLIB allows the specification of a base gpio number for a
> >> > controller. That is not possible using OF. Instead, free gpio numbers
> >> > are assigned.
> >> >
> >> > In order to allow static, predefined gpio numbers, a base property in
> >> > the gpio controller node specifies the first gpio number.
> >> >
> >> > v2, v3: added/improved description of base property in doc
> >>
> >> These version descriptions are better placed below the "---" line. And you
> >> should remove the "Re: " from the subject line. Other than this:
> >>
> >> Acked-by: Stefan Roese <sr@denx.de>

> Yeah, I don't like this patch either.  GPIO numbering is a Linux
> internal detail and has no bearing on the hardware description.  If
> you need to know what a particular gpio number is then it should be
> resolved by finding the device tree node; not by trying to fix a GPIO
> controller to a particular number.

Okay, now I think I understand.

I'll try to solve the chip select pin addressing in the spi driver
differently. Thank you guys!

Wolfgang