Re: [PATCH v1 01/11] PCI: tegra: switch to using devm_fwnode_gpiod_get

On Mon, Sep 05, 2022 at 09:19:02AM +0200, Pali Rohár wrote:

On Sunday 04 September 2022 23:30:53 Dmitry Torokhov wrote:

quoted

I would like to limit (or maybe even remove) use of
[devm_]gpiod_get_from_of_node in drivers so that gpiolib can be cleaned
a bit, so let's switch to the generic device property API. It may even
help with handling secondary fwnodes when gpiolib is taught to handle
gpios described by swnodes.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
index 8e323e93be91..929f9363e94b 100644
--- a/drivers/pci/controller/pci-tegra.c
+++ b/drivers/pci/controller/pci-tegra.c

@@ -2202,10 +2202,11 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
 		 * and in this case fall back to using AFI per port register
 		 * to toggle PERST# SFIO line.
 		 */
-		rp->reset_gpio = devm_gpiod_get_from_of_node(dev, port,
-							     "reset-gpios", 0,
-							     GPIOD_OUT_LOW,
-							     label);
+		rp->reset_gpio = devm_fwnode_gpiod_get(dev,
+						       of_fwnode_handle(port),
+						       "reset",
+						       GPIOD_OUT_LOW,
+						       label);

Why in pci-aardvark.c for PERST# reset-gpio you have used
devm_gpiod_get_optional() and here in pci-tegra.c you have used
devm_fwnode_gpiod_get()? I think that PERST# logic is same in both
drivers.

I believe Andy already answered that, but in this driver we can have
several root ports described via subnodes of dev->of_node, and reset
GPIOs are attached to those subnodes. We are forced to use
devm_fwnode_gpiod_get() instead of devm_gpiod_get_optional() as we need
to supply the exact fwnode we need to look up GPIO in, and can not infer
it from the 'dev' parameter of devm_gpiod_get().

Thanks.

-- 
Dmitry

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel