[net-next,v2,1/2] net:dsa:microchip: add property to select internal RMII reference clock

Microchip KSZ8863/KSZ8873 have the ability to select between internal
and external RMII reference clock. By default, reference clock
needs to be provided via REFCLKI_3 pin. If required, device can be
setup to provide RMII clock internally so that REFCLKI_3 pin can be
left unconnected.
Add a new "microchip,rmii-clk-internal" property which will set
RMII clock reference to internal. If property is not set, reference
clock needs to be provided externally.

Signed-off-by: Ante Knezic <ante.knezic@helmholz.de>
---
 drivers/net/dsa/microchip/ksz8795.c     | 5 +++++
 drivers/net/dsa/microchip/ksz8795_reg.h | 3 +++
 drivers/net/dsa/microchip/ksz_common.c  | 3 +++
 drivers/net/dsa/microchip/ksz_common.h  | 1 +
 4 files changed, 12 insertions(+)

Commit message: "net: dsa: microchip: ".

On Thu, Oct 12, 2023 at 12:55:55PM +0200, Ante Knezic wrote:
> Microchip KSZ8863/KSZ8873 have the ability to select between internal
> and external RMII reference clock. By default, reference clock
> needs to be provided via REFCLKI_3 pin. If required, device can be
> setup to provide RMII clock internally so that REFCLKI_3 pin can be
> left unconnected.
> Add a new "microchip,rmii-clk-internal" property which will set
> RMII clock reference to internal. If property is not set, reference
> clock needs to be provided externally.
> 
> Signed-off-by: Ante Knezic <ante.knezic@helmholz.de>
> ---
>  drivers/net/dsa/microchip/ksz8795.c     | 5 +++++
>  drivers/net/dsa/microchip/ksz8795_reg.h | 3 +++
>  drivers/net/dsa/microchip/ksz_common.c  | 3 +++
>  drivers/net/dsa/microchip/ksz_common.h  | 1 +
>  4 files changed, 12 insertions(+)
> 
> diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
> index 91aba470fb2f..78f3a668aa99 100644
> --- a/drivers/net/dsa/microchip/ksz8795.c
> +++ b/drivers/net/dsa/microchip/ksz8795.c
> @@ -1434,6 +1434,11 @@ int ksz8_setup(struct dsa_switch *ds)
>  	for (i = 0; i < (dev->info->num_vlans / 4); i++)
>  		ksz8_r_vlan_entries(dev, i);
>  
> +	if (ksz_is_ksz88x3(dev))
> +		ksz_cfg(dev, KSZ88X3_REG_FVID_AND_HOST_MODE,
> +			KSZ88X3_PORT3_RMII_CLK_INTERNAL,
> +			dev->rmii_clk_internal);
> +

Can this be done in dev->dev_ops->phylink_mac_config() (which so far has no implementation)
for port 3 of ksz88x3?

>  	return ksz8_handle_global_errata(ds);
>  }
>  
> diff --git a/drivers/net/dsa/microchip/ksz8795_reg.h b/drivers/net/dsa/microchip/ksz8795_reg.h
> index 3c9dae53e4d8..beca974e0171 100644
> --- a/drivers/net/dsa/microchip/ksz8795_reg.h
> +++ b/drivers/net/dsa/microchip/ksz8795_reg.h
> @@ -22,6 +22,9 @@
>  #define KSZ8863_GLOBAL_SOFTWARE_RESET	BIT(4)
>  #define KSZ8863_PCS_RESET		BIT(0)
>  
> +#define KSZ88X3_REG_FVID_AND_HOST_MODE  0xC6
> +#define KSZ88X3_PORT3_RMII_CLK_INTERNAL BIT(3)
> +
>  #define REG_SW_CTRL_0			0x02
>  
>  #define SW_NEW_BACKOFF			BIT(7)
> diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
> index b800ace40ce1..0a0a53ce5b1b 100644
> --- a/drivers/net/dsa/microchip/ksz_common.c
> +++ b/drivers/net/dsa/microchip/ksz_common.c
> @@ -4160,6 +4160,9 @@ int ksz_switch_register(struct ksz_device *dev)
>  		}
>  	}
>  
> +	dev->rmii_clk_internal = of_property_read_bool(dev->dev->of_node,
> +						       "microchip,rmii-clk-internal");

Port property.

> +
>  	ret = dsa_register_switch(dev->ds);
>  	if (ret) {
>  		dev->dev_ops->exit(dev);
> diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
> index 8842efca0871..e5b0445fe2ca 100644
> --- a/drivers/net/dsa/microchip/ksz_common.h
> +++ b/drivers/net/dsa/microchip/ksz_common.h
> @@ -163,6 +163,7 @@ struct ksz_device {
>  	phy_interface_t compat_interface;
>  	bool synclko_125;
>  	bool synclko_disable;
> +	bool rmii_clk_internal;
>  
>  	struct vlan_table *vlan_cache;
>  
> -- 
> 2.11.0