Re: [PATCH net-next v2 4/4] net: dp83869: Add RGMII internal delay configuration

Florian Fainelli
2020-05-22T16:13:44Z

On 5/22/2020 5:25 AM, Dan Murphy wrote:
> Add RGMII internal delay configuration for Rx and Tx.
>
> Signed-off-by: Dan Murphy <dmurphy@ti.com>
> ---
> drivers/net/phy/dp83869.c | 101 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 101 insertions(+)
>
> diff --git a/drivers/net/phy/dp83869.c b/drivers/net/phy/dp83869.c
> index cfb22a21a2e6..a9008d32e2b6 100644
> --- a/drivers/net/phy/dp83869.c
> +++ b/drivers/net/phy/dp83869.c
> @@ -99,6 +99,14 @@
> #define DP83869_OP_MODE_MII BIT(5)
> #define DP83869_SGMII_RGMII_BRIDGE BIT(6)
>
> +/* RGMIIDCTL bits */
> +#define DP83869_RGMII_TX_CLK_DELAY_SHIFT 4
> +#define DP83869_RGMII_CLK_DELAY_INV 0
> +
> +static int dp83869_internal_delay[] = {250, 500, 750, 1000, 1250, 1500, 1750,
> + 2000, 2250, 2500, 2750, 3000, 3250,
> + 3500, 3750, 4000};
> +
> enum {
> DP83869_PORT_MIRRORING_KEEP,
> DP83869_PORT_MIRRORING_EN,
> @@ -108,6 +116,8 @@ enum {
> struct dp83869_private {
> int tx_fifo_depth;
> int rx_fifo_depth;
> + u32 rx_id_delay;
> + u32 tx_id_delay;
> int io_impedance;
> int port_mirroring;
> bool rxctrl_strap_quirk;
> @@ -182,6 +192,7 @@ static int dp83869_of_init(struct phy_device *phydev)
> struct dp83869_private *dp83869 = phydev->priv;
> struct device *dev = &phydev->mdio.dev;
> struct device_node *of_node = dev->of_node;
> + int delay_size = ARRAY_SIZE(dp83869_internal_delay);
> int ret;
>
> if (!of_node)
> @@ -232,6 +243,26 @@ static int dp83869_of_init(struct phy_device *phydev)
> &dp83869->tx_fifo_depth))
> dp83869->tx_fifo_depth = DP83869_PHYCR_FIFO_DEPTH_4_B_NIB;
>
> + dp83869->rx_id_delay = DP83869_RGMII_CLK_DELAY_INV;
> + ret = of_property_read_u32(of_node, "rx-internal-delay-ps",
> + &dp83869->rx_id_delay);
> + if (!ret && dp83869->rx_id_delay > dp83869_internal_delay[delay_size]) {
> + phydev_err(phydev,
> + "rx-internal-delay value of %u out of range\n",
> + dp83869->rx_id_delay);
> + return -EINVAL;
> + }
> +
> + dp83869->tx_id_delay = DP83869_RGMII_CLK_DELAY_INV;
> + ret = of_property_read_u32(of_node, "tx-internal-delay-ps",
> + &dp83869->tx_id_delay);
> + if (!ret && dp83869->tx_id_delay > dp83869_internal_delay[delay_size]) {
> + phydev_err(phydev,
> + "tx-internal-delay value of %u out of range\n",
> + dp83869->tx_id_delay);
> + return -EINVAL;
> + }

This is the kind of validation that I would be expecting from the PHY
library to do, in fact, since you use Device Tree standard property, I
would expect you only need to pass the maximum delay value and some
storage for your array of delays.

> +
> return ret;
> }
> #else
> @@ -270,6 +301,29 @@ static int dp83869_configure_rgmii(struct phy_device *phydev,
> return ret;
> }
>
> +static int dp83869_verify_rgmii_cfg(struct phy_device *phydev)
> +{
> + struct dp83869_private *dp83869 = phydev->priv;
> +
> + /* RX delay *must* be specified if internal delay of RX is used. */
> + if ((phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
> + phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID) &&
> + dp83869->rx_id_delay == DP83869_RGMII_CLK_DELAY_INV) {
> + phydev_err(phydev, "ti,rx-internal-delay must be specified\n");
> + return -EINVAL;
> + }
> +
> + /* TX delay *must* be specified if internal delay of TX is used. */
> + if ((phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
> + phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID) &&
> + dp83869->tx_id_delay == DP83869_RGMII_CLK_DELAY_INV) {
> + phydev_err(phydev, "ti,tx-internal-delay must be specified\n");
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> static int dp83869_configure_mode(struct phy_device *phydev,
> struct dp83869_private *dp83869)
> {
> @@ -371,6 +425,12 @@ static int dp83869_config_init(struct phy_device *phydev)
> {
> struct dp83869_private *dp83869 = phydev->priv;
> int ret, val;
> + int delay_size = ARRAY_SIZE(dp83869_internal_delay);
> + int delay = 0;
> +
> + ret = dp83869_verify_rgmii_cfg(phydev);
> + if (ret)
> + return ret;
>
> ret = dp83869_configure_mode(phydev, dp83869);
> if (ret)
> @@ -394,6 +454,47 @@ static int dp83869_config_init(struct phy_device *phydev)
> dp83869->clk_output_sel <<
> DP83869_IO_MUX_CFG_CLK_O_SEL_SHIFT);
>
> + if (phy_interface_is_rgmii(phydev)) {
> + val = phy_read_mmd(phydev, DP83869_DEVADDR, DP83869_RGMIICTL);
> +
> + val &= ~(DP83869_RGMII_TX_CLK_DELAY_EN | DP83869_RGMII_RX_CLK_DELAY_EN);
> + if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
> + val |= (DP83869_RGMII_TX_CLK_DELAY_EN | DP83869_RGMII_RX_CLK_DELAY_EN);
> +
> + if (phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID)
> + val |= DP83869_RGMII_TX_CLK_DELAY_EN;
> +
> + if (phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID)
> + val |= DP83869_RGMII_RX_CLK_DELAY_EN;
> +
> + phy_write_mmd(phydev, DP83869_DEVADDR, DP83869_RGMIICTL, val);
> +
> + if (dp83869->rx_id_delay) {
> + val = phy_get_delay_index(phydev,
> + &dp83869_internal_delay[0],
> + delay_size,
> + dp83869->rx_id_delay);
> + if (val < 0)
> + return val;
> +
> + delay |= val;

Don't you need to do a bitwise AND with the maximum delay value
supported by the range since you do a Read/Modify/Write operation here?

> + }
> +
> + if (dp83869->tx_id_delay) {
> + val = phy_get_delay_index(phydev,
> + &dp83869_internal_delay[0],
> + delay_size,
> + dp83869->tx_id_delay);
> + if (val < 0)
> + return val;
> +
> + delay |= val << DP83869_RGMII_TX_CLK_DELAY_SHIFT;

Likewise.

> + }
> +
> + phy_write_mmd(phydev, DP83869_DEVADDR, DP83869_RGMIIDCTL,
> + delay);
> + }
> +
> return ret;
> }
>
>

--
Florian