linux-kernel - Re: [PATCH 1/3] net: davicom: dm9000: switch to using gpiod API

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Date:   Fri, 18 Nov 2022 15:33:44 +0000
From:   Paul Cercueil <paul@...pouillou.net>
To:     Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:     "David S. Miller" <davem@...emloft.net>,
        Andrew Lunn <andrew@...n.ch>,
        Heiner Kallweit <hkallweit1@...il.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <brgl@...ev.pl>, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/3] net: davicom: dm9000: switch to using gpiod API

Hi Dmitry,

Le mar. 6 sept. 2022 à 13:49:20 -0700, Dmitry Torokhov 
<dmitry.torokhov@...il.com> a écrit :
> 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.
> 
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
> ---
>  drivers/net/ethernet/davicom/dm9000.c | 26 ++++++++++++++------------
>  1 file changed, 14 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/ethernet/davicom/dm9000.c 
> b/drivers/net/ethernet/davicom/dm9000.c
> index 77229e53b04e..c85a6ebd79fc 100644
> --- a/drivers/net/ethernet/davicom/dm9000.c
> +++ b/drivers/net/ethernet/davicom/dm9000.c
> @@ -28,8 +28,7 @@
>  #include <linux/irq.h>
>  #include <linux/slab.h>
>  #include <linux/regulator/consumer.h>
> -#include <linux/gpio.h>
> -#include <linux/of_gpio.h>
> +#include <linux/gpio/consumer.h>
> 
>  #include <asm/delay.h>
>  #include <asm/irq.h>
> @@ -1421,8 +1420,7 @@ dm9000_probe(struct platform_device *pdev)
>  	int iosize;
>  	int i;
>  	u32 id_val;
> -	int reset_gpios;
> -	enum of_gpio_flags flags;
> +	struct gpio_desc *reset_gpio;
>  	struct regulator *power;
>  	bool inv_mac_addr = false;
>  	u8 addr[ETH_ALEN];
> @@ -1442,20 +1440,24 @@ dm9000_probe(struct platform_device *pdev)
>  		dev_dbg(dev, "regulator enabled\n");
>  	}
> 
> -	reset_gpios = of_get_named_gpio_flags(dev->of_node, "reset-gpios", 
> 0,
> -					      &flags);
> -	if (gpio_is_valid(reset_gpios)) {
> -		ret = devm_gpio_request_one(dev, reset_gpios, flags,
> -					    "dm9000_reset");
> +	reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> +	ret = PTR_ERR_OR_ZERO(reset_gpio);
> +	if (ret) {
> +		dev_err(dev, "failed to request reset gpio: %d\n", ret);
> +		goto out_regulator_disable;
> +	}
> +
> +	if (reset_gpio) {
> +		ret = gpiod_set_consumer_name(reset_gpio, "dm9000_reset");
>  		if (ret) {
> -			dev_err(dev, "failed to request reset gpio %d: %d\n",
> -				reset_gpios, ret);
> +			dev_err(dev, "failed to set reset gpio name: %d\n",
> +				ret);
>  			goto out_regulator_disable;
>  		}
> 
>  		/* According to manual PWRST# Low Period Min 1ms */
>  		msleep(2);
> -		gpio_set_value(reset_gpios, 1);
> +		gpiod_set_value_cansleep(reset_gpio, 0);

Why is that 1 magically turned into a 0?

On my CI20 board I can't get the DM9000 chip to probe correctly with 
this patch (it fails to read the ID).
If I revert this patch then everything works fine.

Cheers,
-Paul

>  		/* Needs 3ms to read eeprom when PWRST is deasserted */
>  		msleep(4);
>  	}
> --
> 2.37.2.789.g6183377224-goog
>