Re: [PATCH net-next v2 2/2] net: ethernet: oa_tc6: add reset-gpios support

[Qingfang Deng <qingfang.deng@linux.dev>]

Hi,

On 2026/9/16 15:53, Alessandro Zini wrote:
> OPEN Alliance 10BASE-T1x MAC-PHY Serial Interface specification
> (v1.1, Section 8.2) defines an external RESET pin as an optional reset
> source for the MAC-PHY.
>
> Add support for an optional reset GPIO in oa_tc6_init(). If specified in
> the device tree, assert the hardware reset line for 10 us and allow 1 ms
> settle time for crystal oscillator startup before performing the initial
> TC6 control protection check and software reset.
>
> Suggested-by: Parthiban Veerasooran <parthiban.veerasooran@microchip.com>
> Signed-off-by: Alessandro Zini <alessandro.zini@siemens.com>
> ---
> Changes in v2:
> - Moved reset GPIO handling from lan865x.c to common oa_tc6.c as suggested
>    by Parthiban Veerasooran.
>
>   drivers/net/ethernet/oa_tc6.c | 21 +++++++++++++++++++++
>   1 file changed, 21 insertions(+)
>
> diff --git a/drivers/net/ethernet/oa_tc6.c b/drivers/net/ethernet/oa_tc6.c
> index 6fcc5f561d560..a697e2cb99cd8 100644
> --- a/drivers/net/ethernet/oa_tc6.c
> +++ b/drivers/net/ethernet/oa_tc6.c
> @@ -11,6 +11,8 @@
>   #include <linux/mdio.h>
>   #include <linux/phy.h>
>   #include <linux/oa_tc6.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/delay.h>
>   
>   /* Control command header */
>   #define OA_TC6_CTRL_HEADER_DATA_NOT_CTRL	BIT(31)
> @@ -88,6 +90,7 @@ struct oa_tc6 {
>   	bool disable_traffic;
>   	bool prot_ctrl;
>   	enum oa_tc6_quirk_flag quirk_flags;
> +	struct gpio_desc *reset_gpio;
>   };
>   
>   enum oa_tc6_header_type {
> @@ -1503,6 +1506,24 @@ struct oa_tc6 *oa_tc6_init(struct spi_device *spi, struct net_device *netdev,
>   	if (!tc6->spi_data_rx_buf)
>   		return NULL;
>   
> +	tc6->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset",
> +						  GPIOD_OUT_LOW);

Please use GPIOD_OUT_HIGH here, so the reset pin is initially asserted, 
and the first gpiod_set_value_cansleep below can be removed. See 
function __mdiobus_register as an example.

> +	if (IS_ERR(tc6->reset_gpio)) {
> +		dev_err_probe(&spi->dev, PTR_ERR(tc6->reset_gpio),
> +			      "Failed to get reset GPIO\n");
> +		return NULL;
> +	}
> +
> +	if (tc6->reset_gpio) {
> +		/* Assert hardware reset for 10 us (datasheet specifies min 5 us)
> +		 * and allow 1 ms settle time for crystal oscillator startup.
> +		 */
> +		gpiod_set_value_cansleep(tc6->reset_gpio, 1);
> +		fsleep(10);
> +		gpiod_set_value_cansleep(tc6->reset_gpio, 0);
> +		fsleep(1000);
> +	}
> +
>   	/* Check the PROTE bit status so that we can reset the device */
>   	ret = oa_tc6_check_ctrl_protection(tc6);
>   	if (ret) {

Kind regards,