Re: [RFC Patch net-next 06/10] net: dsa: microchip: lan937x: add support for configuing xMII register

[Vladimir Oltean <olteanv@gmail.com>]

On Tue, Jul 12, 2022 at 09:33:04PM +0530, Arun Ramadoss wrote:
> This patch add the common ksz_set_xmii function for ksz series switch
> and update the lan937x code phylink mac config. The register address for
> the ksz8795 is Port 5 Interface control 6 and for all other switch is
> xMII Control 1.
> The bit value for selecting the interface is same for
> KSZ8795 and KSZ9893 are same. The bit values for KSZ9477 and lan973x are
> same. So, this patch add the bit value for each switches in
> ksz_chip_data and configure the registers based on the chip id.
> 
> Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
> ---
>  drivers/net/dsa/microchip/ksz_common.c   | 57 ++++++++++++++++++++++++
>  drivers/net/dsa/microchip/ksz_common.h   |  8 ++++
>  drivers/net/dsa/microchip/lan937x_main.c | 32 +------------
>  drivers/net/dsa/microchip/lan937x_reg.h  |  9 ----
>  4 files changed, 66 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
> index 0cb711fcf046..649da4c361c1 100644
> --- a/drivers/net/dsa/microchip/ksz_common.c
> +++ b/drivers/net/dsa/microchip/ksz_common.c
> @@ -284,6 +284,10 @@ static const u32 ksz8795_masks[] = {
>  };
>  
>  static const u8 ksz8795_values[] = {
> +	[P_RGMII_SEL]			= 3,
> +	[P_GMII_SEL]			= 2,
> +	[P_RMII_SEL]			= 1,
> +	[P_MII_SEL]			= 0,
>  	[P_MII_1GBIT]			= 1,
>  	[P_MII_NOT_1GBIT]		= 0,
>  	[P_MII_100MBIT]			= 0,
> @@ -378,6 +382,10 @@ static const u8 ksz9477_shifts[] = {
>  };
>  
>  static const u8 ksz9477_values[] = {
> +	[P_RGMII_SEL]			= 0,
> +	[P_RMII_SEL]			= 1,
> +	[P_GMII_SEL]			= 2,
> +	[P_MII_SEL]			= 3,
>  	[P_MII_1GBIT]			= 0,
>  	[P_MII_NOT_1GBIT]		= 1,
>  	[P_MII_100MBIT]			= 1,
> @@ -387,6 +395,10 @@ static const u8 ksz9477_values[] = {
>  };
>  
>  static const u8 ksz9893_values[] = {
> +	[P_RGMII_SEL]			= 3,
> +	[P_GMII_SEL]			= 2,
> +	[P_RMII_SEL]			= 1,
> +	[P_MII_SEL]			= 0,
>  	[P_MII_1GBIT]			= 1,
>  	[P_MII_NOT_1GBIT]		= 0,
>  	[P_MII_100MBIT]			= 1,
> @@ -1390,6 +1402,51 @@ static int ksz_max_mtu(struct dsa_switch *ds, int port)
>  	return dev->dev_ops->max_mtu(dev, port);
>  }
>  
> +void ksz_set_xmii(struct ksz_device *dev, int port, phy_interface_t interface)
> +{
> +	const u8 *bitval = dev->info->bitval;
> +	const u16 *regs = dev->info->regs;
> +	u8 data8;
> +
> +	ksz_pread8(dev, port, regs[P_XMII_CTRL_1], &data8);
> +
> +	data8 &= ~(P_MII_SEL_M | P_RGMII_ID_IG_ENABLE |
> +		   P_RGMII_ID_EG_ENABLE);
> +
> +	switch (interface) {
> +	case PHY_INTERFACE_MODE_MII:
> +		data8 |= bitval[P_MII_SEL];
> +		break;
> +	case PHY_INTERFACE_MODE_RMII:
> +		data8 |= bitval[P_RMII_SEL];
> +		break;
> +	case PHY_INTERFACE_MODE_GMII:
> +		data8 |= bitval[P_GMII_SEL];
> +		break;
> +	case PHY_INTERFACE_MODE_RGMII:
> +	case PHY_INTERFACE_MODE_RGMII_ID:
> +	case PHY_INTERFACE_MODE_RGMII_TXID:
> +	case PHY_INTERFACE_MODE_RGMII_RXID:
> +		data8 |= bitval[P_RGMII_SEL];
> +		break;
> +	default:
> +		dev_err(dev->dev, "Unsupported interface '%s' for port %d\n",
> +			phy_modes(interface), port);
> +		return;
> +	}
> +
> +	if (interface == PHY_INTERFACE_MODE_RGMII_ID ||
> +	    interface == PHY_INTERFACE_MODE_RGMII_RXID)
> +		data8 |= P_RGMII_ID_IG_ENABLE;
> +
> +	if (interface == PHY_INTERFACE_MODE_RGMII_ID ||
> +	    interface == PHY_INTERFACE_MODE_RGMII_TXID)
> +		data8 |= P_RGMII_ID_EG_ENABLE;

I'm confused to see RGMII delay handling both in ksz_set_xmii() and in
lan937x_phylink_mac_config(), called immediately afterwards via
dev->dev_ops->phylink_mac_config(). Can you explain the differences
between P_RGMII_ID_IG_ENABLE in regs[P_XMII_CTRL_1] and RGMII_1_RX_DELAY_2NS
in REG_PORT_XMII_CTRL_4?

> +
> +	/* Write the updated value */
> +	ksz_pwrite8(dev, port, regs[P_XMII_CTRL_1], data8);
> +}
> +
>  static void ksz_phylink_mac_config(struct dsa_switch *ds, int port,
>  				   unsigned int mode,
>  				   const struct phylink_link_state *state)
> diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
> index db836b376341..90f3ec9ddaec 100644
> --- a/drivers/net/dsa/microchip/ksz_common.h
> +++ b/drivers/net/dsa/microchip/ksz_common.h
> @@ -216,6 +216,10 @@ enum ksz_shifts {
>  };
>  
>  enum ksz_values {
> +	P_RGMII_SEL,
> +	P_RMII_SEL,
> +	P_GMII_SEL,
> +	P_MII_SEL,
>  	P_MII_1GBIT,
>  	P_MII_NOT_1GBIT,
>  	P_MII_100MBIT,
> @@ -311,6 +315,7 @@ void ksz_r_mib_stats64(struct ksz_device *dev, int port);
>  void ksz_port_stp_state_set(struct dsa_switch *ds, int port, u8 state);
>  bool ksz_get_gbit(struct ksz_device *dev, int port);
>  void ksz_set_gbit(struct ksz_device *dev, int port, bool gbit);
> +void ksz_set_xmii(struct ksz_device *dev, int port, phy_interface_t interface);
>  extern const struct ksz_chip_data ksz_switch_chips[];
>  
>  /* Common register access functions */
> @@ -479,6 +484,9 @@ static inline int is_lan937x(struct ksz_device *dev)
>  #define P_MII_100MBIT_M			BIT(4)
>  
>  #define P_MII_1GBIT_M			BIT(6)
> +#define P_RGMII_ID_IG_ENABLE		BIT(4)
> +#define P_RGMII_ID_EG_ENABLE		BIT(3)
> +#define P_MII_SEL_M			0x3
>  
>  /* Regmap tables generation */
>  #define KSZ_SPI_OP_RD		3
> diff --git a/drivers/net/dsa/microchip/lan937x_main.c b/drivers/net/dsa/microchip/lan937x_main.c
> index a2e648eacd19..d86ffdf976b0 100644
> --- a/drivers/net/dsa/microchip/lan937x_main.c
> +++ b/drivers/net/dsa/microchip/lan937x_main.c
> @@ -315,36 +315,6 @@ int lan937x_change_mtu(struct ksz_device *dev, int port, int new_mtu)
>  	return 0;
>  }
>  
> -static void lan937x_mac_config(struct ksz_device *dev, int port,
> -			       phy_interface_t interface)
> -{
> -	u8 data8;
> -
> -	ksz_pread8(dev, port, REG_PORT_XMII_CTRL_1, &data8);
> -
> -	/* clear MII selection & set it based on interface later */
> -	data8 &= ~PORT_MII_SEL_M;
> -
> -	/* configure MAC based on interface */
> -	switch (interface) {
> -	case PHY_INTERFACE_MODE_MII:
> -		ksz_set_gbit(dev, port, false);
> -		data8 |= PORT_MII_SEL;
> -		break;
> -	case PHY_INTERFACE_MODE_RMII:
> -		ksz_set_gbit(dev, port, false);
> -		data8 |= PORT_RMII_SEL;
> -		break;
> -	default:
> -		dev_err(dev->dev, "Unsupported interface '%s' for port %d\n",
> -			phy_modes(interface), port);
> -		return;
> -	}
> -
> -	/* Write the updated value */
> -	ksz_pwrite8(dev, port, REG_PORT_XMII_CTRL_1, data8);
> -}
> -
>  void lan937x_phylink_get_caps(struct ksz_device *dev, int port,
>  			      struct phylink_config *config)
>  {
> @@ -370,7 +340,7 @@ void lan937x_phylink_mac_config(struct ksz_device *dev, int port,
>  		return;
>  	}
>  
> -	lan937x_mac_config(dev, port, state->interface);
> +	ksz_set_xmii(dev, port, state->interface);
>  }
>  
>  int lan937x_setup(struct dsa_switch *ds)
> diff --git a/drivers/net/dsa/microchip/lan937x_reg.h b/drivers/net/dsa/microchip/lan937x_reg.h
> index d5eb6dc3a739..a6cb3ca22dc3 100644
> --- a/drivers/net/dsa/microchip/lan937x_reg.h
> +++ b/drivers/net/dsa/microchip/lan937x_reg.h
> @@ -131,19 +131,10 @@
>  #define REG_PORT_T1_PHY_CTRL_BASE	0x0100
>  
>  /* 3 - xMII */
> -#define REG_PORT_XMII_CTRL_0		0x0300
>  #define PORT_SGMII_SEL			BIT(7)
>  #define PORT_GRXC_ENABLE		BIT(0)
>  
> -#define REG_PORT_XMII_CTRL_1		0x0301
>  #define PORT_MII_SEL_EDGE		BIT(5)
> -#define PORT_RGMII_ID_IG_ENABLE		BIT(4)
> -#define PORT_RGMII_ID_EG_ENABLE		BIT(3)
> -#define PORT_MII_MAC_MODE		BIT(2)
> -#define PORT_MII_SEL_M			0x3
> -#define PORT_RGMII_SEL			0x0
> -#define PORT_RMII_SEL			0x1
> -#define PORT_MII_SEL			0x2
>  
>  /* 4 - MAC */
>  #define REG_PORT_MAC_CTRL_0		0x0400
> -- 
> 2.36.1
>