Re: [PATCH v5 2/5] net: macb: add support for sgmii MAC-PHY interface

From: Russell King - ARM Linux admin
Date: Mon Jun 24 2019 - 09:42:48 EST

On Mon, Jun 24, 2019 at 01:11:14PM +0100, Parshuram Thombare wrote:
> This patch add support for SGMII interface) and
> 2.5Gbps MAC in Cadence ethernet controller driver.
>
> Signed-off-by: Parshuram Thombare <pthombar@xxxxxxxxxxx>
> ---
> drivers/net/ethernet/cadence/macb.h | 54 +++++++++++++-----
> drivers/net/ethernet/cadence/macb_main.c | 72 ++++++++++++++++++++++--
> 2 files changed, 109 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
> index 8629d345af31..6d268283c318 100644
> --- a/drivers/net/ethernet/cadence/macb.h
> +++ b/drivers/net/ethernet/cadence/macb.h
> @@ -77,6 +77,7 @@
> #define MACB_RBQPH 0x04D4
>
> /* GEM register offsets. */
> +#define GEM_NCR 0x0000 /* Network Control */
> #define GEM_NCFGR 0x0004 /* Network Config */
> #define GEM_USRIO 0x000c /* User IO */
> #define GEM_DMACFG 0x0010 /* DMA Configuration */
> @@ -156,6 +157,7 @@
> #define GEM_PEFTN 0x01f4 /* PTP Peer Event Frame Tx Ns */
> #define GEM_PEFRSL 0x01f8 /* PTP Peer Event Frame Rx Sec Low */
> #define GEM_PEFRN 0x01fc /* PTP Peer Event Frame Rx Ns */
> +#define GEM_PCS_CTRL 0x0200 /* PCS Control */
> #define GEM_DCFG1 0x0280 /* Design Config 1 */
> #define GEM_DCFG2 0x0284 /* Design Config 2 */
> #define GEM_DCFG3 0x0288 /* Design Config 3 */
> @@ -271,6 +273,10 @@
> #define MACB_IRXFCS_OFFSET 19
> #define MACB_IRXFCS_SIZE 1
>
> +/* GEM specific NCR bitfields. */
> +#define GEM_TWO_PT_FIVE_GIG_OFFSET 29
> +#define GEM_TWO_PT_FIVE_GIG_SIZE 1
> +
> /* GEM specific NCFGR bitfields. */
> #define GEM_GBE_OFFSET 10 /* Gigabit mode enable */
> #define GEM_GBE_SIZE 1
> @@ -323,6 +329,9 @@
> #define MACB_MDIO_SIZE 1
> #define MACB_IDLE_OFFSET 2 /* The PHY management logic is idle */
> #define MACB_IDLE_SIZE 1
> +#define MACB_DUPLEX_OFFSET 3
> +#define MACB_DUPLEX_SIZE 1
> +
>
> /* Bitfields in TSR */
> #define MACB_UBR_OFFSET 0 /* Used bit read */
> @@ -456,11 +465,17 @@
> #define MACB_REV_OFFSET 0
> #define MACB_REV_SIZE 16
>
> +/* Bitfields in PCS_CONTROL. */
> +#define GEM_PCS_CTRL_RST_OFFSET 15
> +#define GEM_PCS_CTRL_RST_SIZE 1
> +
> /* Bitfields in DCFG1. */
> #define GEM_IRQCOR_OFFSET 23
> #define GEM_IRQCOR_SIZE 1
> #define GEM_DBWDEF_OFFSET 25
> #define GEM_DBWDEF_SIZE 3
> +#define GEM_NO_PCS_OFFSET 0
> +#define GEM_NO_PCS_SIZE 1
>
> /* Bitfields in DCFG2. */
> #define GEM_RX_PKT_BUFF_OFFSET 20
> @@ -633,19 +648,32 @@
> #define MACB_MAN_CODE 2
>
> /* Capability mask bits */
> -#define MACB_CAPS_ISR_CLEAR_ON_WRITE 0x00000001
> -#define MACB_CAPS_USRIO_HAS_CLKEN 0x00000002
> -#define MACB_CAPS_USRIO_DEFAULT_IS_MII_GMII 0x00000004
> -#define MACB_CAPS_NO_GIGABIT_HALF 0x00000008
> -#define MACB_CAPS_USRIO_DISABLED 0x00000010
> -#define MACB_CAPS_JUMBO 0x00000020
> -#define MACB_CAPS_GEM_HAS_PTP 0x00000040
> -#define MACB_CAPS_BD_RD_PREFETCH 0x00000080
> -#define MACB_CAPS_NEEDS_RSTONUBR 0x00000100
> -#define MACB_CAPS_FIFO_MODE 0x10000000
> -#define MACB_CAPS_GIGABIT_MODE_AVAILABLE 0x20000000
> -#define MACB_CAPS_SG_DISABLED 0x40000000
> -#define MACB_CAPS_MACB_IS_GEM 0x80000000
> +#define MACB_CAPS_ISR_CLEAR_ON_WRITE BIT(0)
> +#define MACB_CAPS_USRIO_HAS_CLKEN BIT(1)
> +#define MACB_CAPS_USRIO_DEFAULT_IS_MII_GMII BIT(2)
> +#define MACB_CAPS_NO_GIGABIT_HALF BIT(3)
> +#define MACB_CAPS_USRIO_DISABLED BIT(4)
> +#define MACB_CAPS_JUMBO BIT(5)
> +#define MACB_CAPS_GEM_HAS_PTP BIT(6)
> +#define MACB_CAPS_BD_RD_PREFETCH BIT(7)
> +#define MACB_CAPS_NEEDS_RSTONUBR BIT(8)
> +#define MACB_CAPS_FIFO_MODE BIT(28)
> +#define MACB_CAPS_GIGABIT_MODE_AVAILABLE BIT(29)
> +#define MACB_CAPS_SG_DISABLED BIT(30)
> +#define MACB_CAPS_MACB_IS_GEM BIT(31)
> +#define MACB_CAPS_PCS BIT(24)
> +#define MACB_CAPS_MACB_IS_GEM_GXL BIT(25)
> +
> +#define MACB_GEM7010_IDNUM 0x009
> +#define MACB_GEM7014_IDNU 0x107
> +#define MACB_GEM7014A_IDNUM 0x207
> +#define MACB_GEM7016_IDNUM 0x10a
> +#define MACB_GEM7017_IDNUM 0x00a
> +#define MACB_GEM7017A_IDNUM 0x20a
> +#define MACB_GEM7020_IDNUM 0x003
> +#define MACB_GEM7021_IDNUM 0x00c
> +#define MACB_GEM7021A_IDNUM 0x20c
> +#define MACB_GEM7022_IDNUM 0x00b
>
> /* LSO settings */
> #define MACB_LSO_UFO_ENABLE 0x01
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index ac5b233cd2e5..572691d948e9 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -445,6 +445,8 @@ static void gem_phylink_validate(struct phylink_config *pl_config,
> __ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, };
>
> switch (state->interface) {
> + case PHY_INTERFACE_MODE_NA:
> + case PHY_INTERFACE_MODE_SGMII:
> case PHY_INTERFACE_MODE_GMII:
> case PHY_INTERFACE_MODE_RGMII:
> if (bp->caps & MACB_CAPS_GIGABIT_MODE_AVAILABLE) {
> @@ -480,10 +482,31 @@ static void gem_mac_config(struct phylink_config *pl_config, unsigned int mode,
> {
> struct net_device *netdev = to_net_dev(pl_config->dev);
> struct macb *bp = netdev_priv(netdev);
> + bool change_interface = bp->phy_interface != state->interface;
> unsigned long flags;
>
> spin_lock_irqsave(&bp->lock, flags);
>
> + if (change_interface) {
> + bp->phy_interface = state->interface;
> + gem_writel(bp, NCR, ~GEM_BIT(TWO_PT_FIVE_GIG) &
> + gem_readl(bp, NCR));

This could do with a comment, such as the one I gave in my example.

> +
> + if (state->interface == PHY_INTERFACE_MODE_SGMII) {
> + gem_writel(bp, NCFGR, GEM_BIT(SGMIIEN) |
> + GEM_BIT(PCSSEL) |
> + gem_readl(bp, NCFGR));
> + } else {
> + /* Disable SGMII mode and PCS */
> + gem_writel(bp, NCFGR, ~(GEM_BIT(SGMIIEN) |
> + GEM_BIT(PCSSEL)) &
> + gem_readl(bp, NCFGR));
> + /* Reset PCS */
> + gem_writel(bp, PCS_CTRL, gem_readl(bp, PCS_CTRL) |
> + GEM_BIT(PCS_CTRL_RST));
> + }
> + }

Good.

> +
> if (!phylink_autoneg_inband(mode) &&
> (bp->speed != state->speed ||
> bp->duplex != state->duplex)) {
> @@ -493,6 +516,7 @@ static void gem_mac_config(struct phylink_config *pl_config, unsigned int mode,
> reg &= ~(MACB_BIT(SPD) | MACB_BIT(FD));
> if (macb_is_gem(bp))
> reg &= ~GEM_BIT(GBE);
> +

Useless change.

> if (state->duplex)
> reg |= MACB_BIT(FD);
>
> @@ -587,8 +611,8 @@ static int macb_mii_probe(struct net_device *dev)
> }
>
> bp->link = 0;
> - bp->speed = 0;
> - bp->duplex = -1;
> + bp->speed = SPEED_UNKNOWN;
> + bp->duplex = DUPLEX_UNKNOWN;
>
> return ret;
> }
> @@ -3337,6 +3361,22 @@ static void macb_configure_caps(struct macb *bp,
> dcfg = gem_readl(bp, DCFG1);
> if (GEM_BFEXT(IRQCOR, dcfg) == 0)
> bp->caps |= MACB_CAPS_ISR_CLEAR_ON_WRITE;
> + if (GEM_BFEXT(NO_PCS, dcfg) == 0)
> + bp->caps |= MACB_CAPS_PCS;
> + switch (MACB_BFEXT(IDNUM, macb_readl(bp, MID))) {
> + case MACB_GEM7016_IDNUM:
> + case MACB_GEM7017_IDNUM:
> + case MACB_GEM7017A_IDNUM:
> + case MACB_GEM7020_IDNUM:
> + case MACB_GEM7021_IDNUM:
> + case MACB_GEM7021A_IDNUM:
> + case MACB_GEM7022_IDNUM:
> + bp->caps |= MACB_CAPS_USRIO_DISABLED;
> + bp->caps |= MACB_CAPS_MACB_IS_GEM_GXL;
> + break;
> + default:
> + break;
> + }
> dcfg = gem_readl(bp, DCFG2);
> if ((dcfg & (GEM_BIT(RX_PKT_BUFF) | GEM_BIT(TX_PKT_BUFF))) == 0)
> bp->caps |= MACB_CAPS_FIFO_MODE;
> @@ -4319,11 +4359,35 @@ static int macb_probe(struct platform_device *pdev)
> }
>
> phy_mode = of_get_phy_mode(np);
> - if (phy_mode < 0)
> + if (phy_mode < 0) {
> /* not found in DT, MII by default */
> bp->phy_interface = PHY_INTERFACE_MODE_MII;
> - else
> + } else if (bp->caps & MACB_CAPS_MACB_IS_GEM_GXL) {
> + u32 interface_supported = 1;
> +
> + if (phy_mode == PHY_INTERFACE_MODE_SGMII) {
> + if (!(bp->caps & MACB_CAPS_PCS))
> + interface_supported = 0;

So if bp->caps does not have MACB_CAPS_PCS set, then SGMII mode is not
supported?

In which case, gem_phylink_validate() must clear the support mask when
SGMII mode is requested to indicate that the interface mode is not
supported.

The same goes for _all_ other PHY link modes that the hardware does not
actually support, such as PHY_INTERFACE_MODE_10GKR...

> + } else if (phy_mode == PHY_INTERFACE_MODE_GMII ||
> + phy_mode == PHY_INTERFACE_MODE_RGMII) {
> + if (!macb_is_gem(bp))
> + interface_supported = 0;
> + } else if (phy_mode != PHY_INTERFACE_MODE_RMII &&
> + phy_mode != PHY_INTERFACE_MODE_MII) {
> + /* Add new mode before this */
> + interface_supported = 0;
> + }

... and the same goes for these too.

> +
> + if (!interface_supported) {
> + netdev_err(dev, "Phy mode %s not supported",
> + phy_modes(phy_mode));
> + goto err_out_free_netdev;
> + }
> +
> + bp->phy_interface = phy_mode;
> + } else {
> bp->phy_interface = phy_mode;
> + }
>
> /* IP specific init */
> err = init(pdev);
> --
> 2.17.1
>
>

--
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