From: Bartosz Golaszewski <brgl@bgdev.pl>
To: Linus Walleij <linus.walleij@linaro.org>,
Andy Shevchenko <andy@kernel.org>
Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
Dipen Patel <dipenp@nvidia.com>,
Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Subject: [RFC/RFT PATCH] gpiolib: reverse-assign the fwnode to struct gpio_chip
Date: Fri, 6 Oct 2023 13:51:47 +0200 [thread overview]
Message-ID: <20231006115147.18559-1-brgl@bgdev.pl> (raw)
From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
struct gpio_chip is not only used to carry the information needed to
set-up a GPIO device but is also used in all GPIOLIB callbacks and is
passed to the matching functions of lookup helpers.
In that last case, it is currently impossible to match a GPIO device by
fwnode unless it was explicitly assigned to the chip in the provider
code. If the fwnode is taken from the parent device, the pointer in
struct gpio_chip will remain NULL.
If we have a parent device but gc->fwnode was not assigned by the
provider, let's assign it ourselves so that lookup by fwnode can work in
all cases.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
This is something that Dipen reported with one of the tegra drivers where
a GPIO lookup by fwnode does not work because the fwnode pointer in struct
gpio_chip is NULL. This patch addresses this use-case.
drivers/gpio/gpiolib.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 191f9c87b4d0..a0e3d255fb73 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -782,6 +782,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
struct lock_class_key *lock_key,
struct lock_class_key *request_key)
{
+ struct fwnode_handle *parent_fwnode;
struct gpio_device *gdev;
unsigned long flags;
unsigned int i;
@@ -806,10 +807,13 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
* If the calling driver did not initialize firmware node,
* do it here using the parent device, if any.
*/
- if (gc->fwnode)
+ if (gc->fwnode) {
device_set_node(&gdev->dev, gc->fwnode);
- else if (gc->parent)
- device_set_node(&gdev->dev, dev_fwnode(gc->parent));
+ } else if (gc->parent) {
+ parent_fwnode = dev_fwnode(gc->parent);
+ device_set_node(&gdev->dev, parent_fwnode);
+ gc->fwnode = parent_fwnode;
+ }
gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
if (gdev->id < 0) {
--
2.39.2
next reply other threads:[~2023-10-06 11:52 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-06 11:51 Bartosz Golaszewski [this message]
2023-10-06 13:14 ` [RFC/RFT PATCH] gpiolib: reverse-assign the fwnode to struct gpio_chip Andy Shevchenko
2023-10-06 19:07 ` Bartosz Golaszewski
2023-10-07 7:45 ` Andy Shevchenko
2023-10-07 15:53 ` Linus Walleij
2023-10-09 18:28 ` Bartosz Golaszewski
2023-10-06 13:24 ` Andy Shevchenko
2023-10-06 19:07 ` Bartosz Golaszewski
2023-10-06 22:22 ` Linus Walleij
2023-10-07 7:39 ` Andy Shevchenko
2023-10-07 7:36 ` Andy Shevchenko
2023-10-06 22:14 ` Linus Walleij
2023-10-07 7:03 ` Andy Shevchenko
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