linux-kernel - Re: [PATCH 2/2] PCI: mvebu: switch to using gpiod API

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Date:   Tue, 6 Sep 2022 23:16:28 +0200
From:   Pali Rohár <pali@...nel.org>
To:     Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:     Shawn Guo <shawn.guo@...aro.org>,
        Lorenzo Pieralisi <lpieralisi@...nel.org>,
        Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
        Bjorn Helgaas <bhelgaas@...gle.com>,
        Rob Herring <robh@...nel.org>,
        Krzysztof Wilczyński <kw@...ux.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <brgl@...ev.pl>, linux-pci@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] PCI: mvebu: switch to using gpiod API

Hello!

On Tuesday 06 September 2022 13:43:01 Dmitry Torokhov wrote:
> This patch switches the driver away from legacy gpio/of_gpio API to
> gpiod API, and removes use of of_get_named_gpio_flags() which I want to
> make private to gpiolib.

There are many pending pci-mvebu.c patches waiting for review and merge,
so I would suggest to wait until all other mvebu patches are processed
and then process this one... longer waiting period :-(

> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
> ---
>  drivers/pci/controller/pci-mvebu.c | 48 +++++++++---------------------
>  1 file changed, 14 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c
> index 1ced73726a26..a54beb8f611c 100644
> --- a/drivers/pci/controller/pci-mvebu.c
> +++ b/drivers/pci/controller/pci-mvebu.c
> @@ -11,14 +11,13 @@
>  #include <linux/bitfield.h>
>  #include <linux/clk.h>
>  #include <linux/delay.h>
> -#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
>  #include <linux/init.h>
>  #include <linux/mbus.h>
>  #include <linux/slab.h>
>  #include <linux/platform_device.h>
>  #include <linux/of_address.h>
>  #include <linux/of_irq.h>
> -#include <linux/of_gpio.h>
>  #include <linux/of_pci.h>
>  #include <linux/of_platform.h>
>  
> @@ -1261,9 +1260,8 @@ static int mvebu_pcie_parse_port(struct mvebu_pcie *pcie,
>  	struct mvebu_pcie_port *port, struct device_node *child)
>  {
>  	struct device *dev = &pcie->pdev->dev;
> -	enum of_gpio_flags flags;
>  	u32 slot_power_limit;
> -	int reset_gpio, ret;
> +	int ret;
>  	u32 num_lanes;
>  
>  	port->pcie = pcie;
> @@ -1327,40 +1325,22 @@ static int mvebu_pcie_parse_port(struct mvebu_pcie *pcie,
>  			 port->name, child);
>  	}
>  
> -	reset_gpio = of_get_named_gpio_flags(child, "reset-gpios", 0, &flags);
> -	if (reset_gpio == -EPROBE_DEFER) {
> -		ret = reset_gpio;
> +	port->reset_name = devm_kasprintf(dev, GFP_KERNEL, "%s-reset",
> +					  port->name);
> +	if (!port->reset_name) {
> +		ret = -ENOMEM;
>  		goto err;
>  	}
>  
> -	if (gpio_is_valid(reset_gpio)) {
> -		unsigned long gpio_flags;
> -
> -		port->reset_name = devm_kasprintf(dev, GFP_KERNEL, "%s-reset",
> -						  port->name);
> -		if (!port->reset_name) {
> -			ret = -ENOMEM;
> +	port->reset_gpio = devm_fwnode_gpiod_get(dev, of_fwnode_handle(child),
> +						 "reset", GPIOD_OUT_HIGH,

What does it mean that there is a new GPIOD_OUT_HIGH flag passed to the
devm_fwnode_gpiod_get() function?

> +						 port->name);
> +	ret = PTR_ERR_OR_ZERO(port->reset_gpio);
> +	if (ret) {
> +		if (ret	!= -ENOENT)
>  			goto err;
> -		}
> -
> -		if (flags & OF_GPIO_ACTIVE_LOW) {
> -			dev_info(dev, "%pOF: reset gpio is active low\n",
> -				 child);
> -			gpio_flags = GPIOF_ACTIVE_LOW |
> -				     GPIOF_OUT_INIT_LOW;
> -		} else {
> -			gpio_flags = GPIOF_OUT_INIT_HIGH;
> -		}
> -
> -		ret = devm_gpio_request_one(dev, reset_gpio, gpio_flags,
> -					    port->reset_name);
> -		if (ret) {
> -			if (ret == -EPROBE_DEFER)
> -				goto err;
> -			goto skip;
> -		}
> -
> -		port->reset_gpio = gpio_to_desc(reset_gpio);
> +		/* reset gpio is optional */
> +		port->reset_gpio = NULL;

Maybe you can also release port->reset_name as it is not used at this
stage?

>  	}
>  
>  	slot_power_limit = of_pci_get_slot_power_limit(child,
> -- 
> 2.37.2.789.g6183377224-goog
>