[PATCH 06/14] net: phy: ksz90x1: Handle ksz9131 LED errata

[Marek Vasut]

On 10/24/24 5:24 PM, Paul Barker wrote:
> Micrel KSZ9131 PHY LED behavior is not correct when configured in
> Individual Mode, LED1 (Activity LED) is in the ON state when there is
> no-link.
> 
> Workaround this by setting bit 9 of register 0x1e after verifying that
> the LED configuration is Individual Mode.
> 
> This issue is described in KSZ9131RNX Silicon Errata DS80000693B [*]
> and according to that it will not be corrected in a future silicon
> revision.
> 
> [*] https://ww1.microchip.com/downloads/en/DeviceDoc/KSZ9131RNX-Silicon-Errata-and-Data-Sheet-Clarification-80000863B.pdf
> 
> Based on commit 0316c7e66bbd in the Linux kernel.
> 
> Signed-off-by: Paul Barker <paul.barker.ct at bp.renesas.com>
> ---
>   drivers/net/phy/micrel_ksz90x1.c | 24 ++++++++++++++++++++++++
>   1 file changed, 24 insertions(+)
> 
> diff --git a/drivers/net/phy/micrel_ksz90x1.c b/drivers/net/phy/micrel_ksz90x1.c
> index c48ae6e88f30..4f99b115a3c7 100644
> --- a/drivers/net/phy/micrel_ksz90x1.c
> +++ b/drivers/net/phy/micrel_ksz90x1.c
> @@ -436,6 +436,26 @@ static int ksz9131_config_rgmii_delay(struct phy_device *phydev)
>   	return ret;
>   }
>   
> +/* Silicon Errata DS80000693B
> + *
> + * When LEDs are configured in Individual Mode, LED1 is ON in a no-link
> + * condition. Workaround is to set register 0x1e, bit 9, this way LED1 behaves
> + * according to the datasheet (off if there is no link).
> + */
> +static int ksz9131_led_errata(struct phy_device *phydev)
> +{
> +	int reg;
> +
> +	reg = phy_read_mmd(phydev, KSZ9131RN_MMD_COMMON_CTRL_REG, 0);
> +	if (reg < 0)
> +		return reg;
> +
> +	if (!(reg & BIT(4)))
It would be good to have symbolic names for these BIT()s , please add 
some #define ... macros .