[U-Boot] [PATCH 6/9] net: sun8i_emac: Support RX/TX delay chains

[Chen-Yu Tsai]

On Wed, Sep 27, 2017 at 11:53 PM, Joe Hershberger
<joe.hershberger at ni.com> wrote:
> On Fri, Sep 22, 2017 at 2:26 AM, Chen-Yu Tsai <wens at csie.org> wrote:
>> The EMAC syscon has configurable RX/TX delay chains for use with RGMII
>> PHYs.
>>
>> This adds support for configuring them via device tree properties. The
>> property names and format were defined in Linux's dwmac-sun8i binding
>> that was merged at one point.
>>
>> Signed-off-by: Chen-Yu Tsai <wens at csie.org>
>> ---
>>  drivers/net/sun8i_emac.c | 25 +++++++++++++++++++++++++
>>  1 file changed, 25 insertions(+)
>>
>> diff --git a/drivers/net/sun8i_emac.c b/drivers/net/sun8i_emac.c
>> index 09bbb2cdb5ca..5fa1b4c170d7 100644
>> --- a/drivers/net/sun8i_emac.c
>> +++ b/drivers/net/sun8i_emac.c
>> @@ -56,6 +56,10 @@
>>  #define H3_EPHY_SELECT         BIT(15) /* 1: internal PHY, 0: external PHY */
>>
>>  #define SC_RMII_EN             BIT(13)
>> +#define SC_TXDC_SHIFT          10
>> +#define SC_TXDC_MASK           GENMASK(2, 0)
>> +#define SC_RXDC_SHIFT          5
>> +#define SC_RXDC_MASK           GENMASK(4, 0)
>>  #define SC_EPIT                        BIT(2) /* 1: RGMII, 0: MII */
>>  #define SC_ETCS_MASK           GENMASK(1, 0)
>>  #define SC_ETCS_EXT_GMII       0x1
>> @@ -125,6 +129,8 @@ struct emac_eth_dev {
>>         u32 addr;
>>         u32 tx_slot;
>>         bool use_internal_phy;
>> +       u32 tx_delay;
>> +       u32 rx_delay;
>>
>>         enum emac_variant variant;
>>         void *mac_reg;
>> @@ -290,6 +296,12 @@ static int sun8i_emac_set_syscon(struct emac_eth_dev *priv)
>>         if (priv->variant == H3_EMAC || priv->variant == A64_EMAC)
>>                 reg &= ~SC_RMII_EN;
>>
>> +       /* Configure RX/TX delay chains */
>> +       reg &= ~(SC_RXDC_MASK << SC_RXDC_SHIFT);
>> +       reg &= ~(SC_TXDC_MASK << SC_TXDC_SHIFT);
>> +       reg |= (priv->rx_delay & SC_RXDC_MASK) << SC_RXDC_SHIFT;
>> +       reg |= (priv->tx_delay & SC_TXDC_MASK) << SC_TXDC_SHIFT;
>
> Why not use bitfield_replace_by_mask() from include/bitfield.h?

Because I wasn't aware of such helpers. If that's preferred I'll
respin the patch.

ChenYu

>> +
>>         switch (priv->interface) {
>>         case PHY_INTERFACE_MODE_MII:
>>                 /* default */
>> @@ -836,6 +848,19 @@ static int sun8i_emac_eth_ofdata_to_platdata(struct udevice *dev)
>>         }
>>  #endif
>>
>> +       /* Get RX/TX delays for RGMII */
>> +       priv->rx_delay = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
>> +                                        "allwinner,rx-delay-ps", 0);
>> +       if (priv->rx_delay % 100 || priv->rx_delay > 3100)
>> +               debug("%s: invalid rx delay value\n", __func__);
>> +       priv->rx_delay /= 100;
>> +
>> +       priv->tx_delay = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
>> +                                        "allwinner,tx-delay-ps", 0);
>> +       if (priv->tx_delay % 100 || priv->tx_delay > 800)
>> +               debug("%s: invalid tx delay value\n", __func__);
>> +       priv->tx_delay /= 100;
>> +
>>         return 0;
>>  }
>>
>> --
>> 2.14.1
>>
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