* Re: [RFC PATCH] gpio: of: fix GPIO drivers with multiple gpio_chip for a single node
2016-10-24 7:43 [RFC PATCH] gpio: of: fix GPIO drivers with multiple gpio_chip for a single node Masahiro Yamada
@ 2016-10-24 16:58 ` Sylvain Lemieux
2016-10-25 1:46 ` Masahiro Yamada
2016-10-24 21:31 ` [RFC] " David Lechner
2016-10-24 22:07 ` [RFC PATCH] " Vladimir Zapolskiy
2 siblings, 1 reply; 5+ messages in thread
From: Sylvain Lemieux @ 2016-10-24 16:58 UTC (permalink / raw)
To: Masahiro Yamada
Cc: linux-gpio, Linus Walleij, Vladimir Zapolskiy, Alexandre Courbot,
linux-kernel, Axel Haslam
Hi Masahiro,
On Mon, 2016-10-24 at 16:43 +0900, Masahiro Yamada wrote:
> Sylvain Lemieux reports the LPC32xx GPIO driver is broken since
> commit 762c2e46c059 ("gpio: of: remove of_gpiochip_and_xlate() and
> struct gg_data"). Probably, gpio-etraxfs.c and gpio-davinci.c are
> broken as well.
>
> Those drivers register multiple gpio_chip that are associated to a
> single OF node, and their own .of_xlate() checks if the passed
> gpio_chip is valid.
>
> Now, the problem is of_find_gpiochip_by_node() returns the first
> gpio_chip found to match the given node. So, .of_xlate() fails,
> except for the first GPIO bank.
>
> Reverting the commit could be a solution, but I do not want to go
> back to the mess of struct gg_data. Another solution here is to
> take the match by a node pointer and the success of .of_xlate().
> It is a bit clumsy to call .of_xlate twice; for gpio_chip matching
> and for really getting the gpio_desc index. Perhaps, the long-term
> goal might be to convert drivers to single chip registration, but
> this commit will solve the problem until then.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> Reported-by: <slemieux.tyco@gmail.com>
> ---
>
> drivers/gpio/gpiolib-of.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
> index ecad3f0..f996596 100644
> --- a/drivers/gpio/gpiolib-of.c
> +++ b/drivers/gpio/gpiolib-of.c
> @@ -26,14 +26,18 @@
>
> #include "gpiolib.h"
>
> -static int of_gpiochip_match_node(struct gpio_chip *chip, void *data)
> +static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
> {
> - return chip->gpiodev->dev.of_node == data;
> + struct of_phandle_args *gpiospec = data;
> +
> + return chip->gpiodev->dev.of_node == gpiospec->np &&
> + !chip->of_xlate(chip, gpiospec, NULL);
for the patch to work, the second compare of the return statement
should be updated:
return chip->gpiodev->dev.of_node == gpiospec->np &&
chip->of_xlate(chip, gpiospec, NULL) >= 0;
the patch, with this return statement, is fixing the issue;
can you submit an updated version of your patch?
> }
>
> -static struct gpio_chip *of_find_gpiochip_by_node(struct device_node *np)
> +static struct gpio_chip *of_find_gpiochip_by_xlate(
> + struct of_phandle_args *gpiospec)
> {
> - return gpiochip_find(np, of_gpiochip_match_node);
> + return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate);
> }
>
> static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
> @@ -79,7 +83,7 @@ struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
> return ERR_PTR(ret);
> }
>
> - chip = of_find_gpiochip_by_node(gpiospec.np);
> + chip = of_find_gpiochip_by_xlate(&gpiospec);
> if (!chip) {
> desc = ERR_PTR(-EPROBE_DEFER);
> goto out;
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [RFC PATCH] gpio: of: fix GPIO drivers with multiple gpio_chip for a single node
2016-10-24 16:58 ` Sylvain Lemieux
@ 2016-10-25 1:46 ` Masahiro Yamada
0 siblings, 0 replies; 5+ messages in thread
From: Masahiro Yamada @ 2016-10-25 1:46 UTC (permalink / raw)
To: Sylvain Lemieux
Cc: linux-gpio, Linus Walleij, Vladimir Zapolskiy, Alexandre Courbot,
Linux Kernel Mailing List, Axel Haslam
2016-10-25 1:58 GMT+09:00 Sylvain Lemieux <slemieux.tyco@gmail.com>:
> Hi Masahiro,
>
> On Mon, 2016-10-24 at 16:43 +0900, Masahiro Yamada wrote:
>> Sylvain Lemieux reports the LPC32xx GPIO driver is broken since
>> commit 762c2e46c059 ("gpio: of: remove of_gpiochip_and_xlate() and
>> struct gg_data"). Probably, gpio-etraxfs.c and gpio-davinci.c are
>> broken as well.
>>
>> Those drivers register multiple gpio_chip that are associated to a
>> single OF node, and their own .of_xlate() checks if the passed
>> gpio_chip is valid.
>>
>> Now, the problem is of_find_gpiochip_by_node() returns the first
>> gpio_chip found to match the given node. So, .of_xlate() fails,
>> except for the first GPIO bank.
>>
>> Reverting the commit could be a solution, but I do not want to go
>> back to the mess of struct gg_data. Another solution here is to
>> take the match by a node pointer and the success of .of_xlate().
>> It is a bit clumsy to call .of_xlate twice; for gpio_chip matching
>> and for really getting the gpio_desc index. Perhaps, the long-term
>> goal might be to convert drivers to single chip registration, but
>> this commit will solve the problem until then.
>>
>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>> Reported-by: <slemieux.tyco@gmail.com>
>> ---
>>
>> drivers/gpio/gpiolib-of.c | 14 +++++++++-----
>> 1 file changed, 9 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
>> index ecad3f0..f996596 100644
>> --- a/drivers/gpio/gpiolib-of.c
>> +++ b/drivers/gpio/gpiolib-of.c
>> @@ -26,14 +26,18 @@
>>
>> #include "gpiolib.h"
>>
>> -static int of_gpiochip_match_node(struct gpio_chip *chip, void *data)
>> +static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
>> {
>> - return chip->gpiodev->dev.of_node == data;
>> + struct of_phandle_args *gpiospec = data;
>> +
>> + return chip->gpiodev->dev.of_node == gpiospec->np &&
>> + !chip->of_xlate(chip, gpiospec, NULL);
>
> for the patch to work, the second compare of the return statement
> should be updated:
> return chip->gpiodev->dev.of_node == gpiospec->np &&
> chip->of_xlate(chip, gpiospec, NULL) >= 0;
>
> the patch, with this return statement, is fixing the issue;
> can you submit an updated version of your patch?
>
Thanks for correction.
I've sent v2.
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC] gpio: of: fix GPIO drivers with multiple gpio_chip for a single node
2016-10-24 7:43 [RFC PATCH] gpio: of: fix GPIO drivers with multiple gpio_chip for a single node Masahiro Yamada
2016-10-24 16:58 ` Sylvain Lemieux
@ 2016-10-24 21:31 ` David Lechner
2016-10-24 22:07 ` [RFC PATCH] " Vladimir Zapolskiy
2 siblings, 0 replies; 5+ messages in thread
From: David Lechner @ 2016-10-24 21:31 UTC (permalink / raw)
To: Masahiro Yamada, linux-gpio
Cc: Linus Walleij, Vladimir Zapolskiy, Alexandre Courbot,
linux-kernel, Axel Haslam, Sekhar Nori, Kevin Hilman
On 10/24/2016 02:43 AM, Masahiro Yamada wrote:
> Sylvain Lemieux reports the LPC32xx GPIO driver is broken since
> commit 762c2e46c059 ("gpio: of: remove of_gpiochip_and_xlate() and
> struct gg_data"). Probably, gpio-etraxfs.c and gpio-davinci.c are
> broken as well.
>
> Those drivers register multiple gpio_chip that are associated to a
> single OF node, and their own .of_xlate() checks if the passed
> gpio_chip is valid.
>
> Now, the problem is of_find_gpiochip_by_node() returns the first
> gpio_chip found to match the given node. So, .of_xlate() fails,
> except for the first GPIO bank.
>
> Reverting the commit could be a solution, but I do not want to go
> back to the mess of struct gg_data. Another solution here is to
> take the match by a node pointer and the success of .of_xlate().
> It is a bit clumsy to call .of_xlate twice; for gpio_chip matching
> and for really getting the gpio_desc index. Perhaps, the long-term
> goal might be to convert drivers to single chip registration, but
> this commit will solve the problem until then.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> Reported-by: <slemieux.tyco@gmail.com>
This fixes gpio-davinci. Tested on LEGO MINDSTORMS EV3 (I included the
chip->of_xlate(chip, gpiospec, NULL) >= 0 suggestion from Sylvain
Lemieux when I tested).
Tested-By: David Lechner <david@lechnology.com>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [RFC PATCH] gpio: of: fix GPIO drivers with multiple gpio_chip for a single node
2016-10-24 7:43 [RFC PATCH] gpio: of: fix GPIO drivers with multiple gpio_chip for a single node Masahiro Yamada
2016-10-24 16:58 ` Sylvain Lemieux
2016-10-24 21:31 ` [RFC] " David Lechner
@ 2016-10-24 22:07 ` Vladimir Zapolskiy
2 siblings, 0 replies; 5+ messages in thread
From: Vladimir Zapolskiy @ 2016-10-24 22:07 UTC (permalink / raw)
To: Masahiro Yamada, linux-gpio
Cc: Linus Walleij, Alexandre Courbot, linux-kernel
Hi Masahiro,
On 24.10.2016 10:43, Masahiro Yamada wrote:
> Sylvain Lemieux reports the LPC32xx GPIO driver is broken since
> commit 762c2e46c059 ("gpio: of: remove of_gpiochip_and_xlate() and
> struct gg_data"). Probably, gpio-etraxfs.c and gpio-davinci.c are
> broken as well.
>
> Those drivers register multiple gpio_chip that are associated to a
> single OF node, and their own .of_xlate() checks if the passed
> gpio_chip is valid.
>
> Now, the problem is of_find_gpiochip_by_node() returns the first
> gpio_chip found to match the given node. So, .of_xlate() fails,
> except for the first GPIO bank.
>
> Reverting the commit could be a solution, but I do not want to go
> back to the mess of struct gg_data. Another solution here is to
> take the match by a node pointer and the success of .of_xlate().
> It is a bit clumsy to call .of_xlate twice; for gpio_chip matching
> and for really getting the gpio_desc index. Perhaps, the long-term
> goal might be to convert drivers to single chip registration, but
> this commit will solve the problem until then.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> Reported-by: <slemieux.tyco@gmail.com>
Fixes: 762c2e46c059 ("gpio: of: remove of_gpiochip_and_xlate() and struct gg_data")
> ---
>
> drivers/gpio/gpiolib-of.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
> index ecad3f0..f996596 100644
> --- a/drivers/gpio/gpiolib-of.c
> +++ b/drivers/gpio/gpiolib-of.c
> @@ -26,14 +26,18 @@
>
> #include "gpiolib.h"
>
> -static int of_gpiochip_match_node(struct gpio_chip *chip, void *data)
> +static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
> {
> - return chip->gpiodev->dev.of_node == data;
> + struct of_phandle_args *gpiospec = data;
> +
> + return chip->gpiodev->dev.of_node == gpiospec->np &&
> + !chip->of_xlate(chip, gpiospec, NULL);
That's an awful but hopefully safe hack to support 3-4 broken GPIO
drivers, however it should work with a correction given by Sylvain.
Here I would recommend to expand the statement, so it will be easier
to simplify it in future:
if (chip->gpiodev->dev.of_node != gpiospec->np)
return 0;
if (chip->of_xlate(chip, gpiospec, NULL) < 0)
return 0;
return 1;
As far as I can say it should work correctly with of_gpio_simple_xlate(),
brcmstb_gpio_of_xlate(), lpc32xx_of_xlate(), davinci_gpio_of_xlate(),
pxa_gpio_of_xlate() and etraxfs_gpio_of_xlate() flavours.
> }
>
> -static struct gpio_chip *of_find_gpiochip_by_node(struct device_node *np)
> +static struct gpio_chip *of_find_gpiochip_by_xlate(
> + struct of_phandle_args *gpiospec)
> {
> - return gpiochip_find(np, of_gpiochip_match_node);
> + return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate);
> }
>
> static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
> @@ -79,7 +83,7 @@ struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
> return ERR_PTR(ret);
> }
>
> - chip = of_find_gpiochip_by_node(gpiospec.np);
> + chip = of_find_gpiochip_by_xlate(&gpiospec);
> if (!chip) {
> desc = ERR_PTR(-EPROBE_DEFER);
> goto out;
>
--
With best wishes,
Vladimir
^ permalink raw reply [flat|nested] 5+ messages in thread