On 7/23/20 1:09 PM, Bryan Whitehead wrote:
> The LCPLL Reset sequence is added to the initialization path
> of the VSC8574 Family of phy drivers.
>
> The LCPLL Reset sequence is known to reduce hardware inter-op
> issues when using the QSGMII MAC interface.
>
> This patch is submitted to net-next to avoid merging conflicts that
> may arise if submitted to net.
>
> Signed-off-by: Bryan Whitehead <bryan.whiteh...@microchip.com>
Can you copy the PHY library maintainers for future changes such that
this does not escape their review?
> ---
> drivers/net/phy/mscc/mscc_main.c | 90
> ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 90 insertions(+)
>
> diff --git a/drivers/net/phy/mscc/mscc_main.c
> b/drivers/net/phy/mscc/mscc_main.c
> index a4fbf3a..f2fa221 100644
> --- a/drivers/net/phy/mscc/mscc_main.c
> +++ b/drivers/net/phy/mscc/mscc_main.c
> @@ -929,6 +929,90 @@ static bool vsc8574_is_serdes_init(struct phy_device
> *phydev)
> }
>
> /* bus->mdio_lock should be locked when using this function */
> +/* Page should already be set to MSCC_PHY_PAGE_EXTENDED_GPIO */
> +static int vsc8574_wait_for_micro_complete(struct phy_device *phydev)
> +{
> + u16 timeout = 500;
> + u16 reg18g = 0;
> +
> + reg18g = phy_base_read(phydev, 18);
> + while (reg18g & 0x8000) {
> + timeout--;
> + if (timeout == 0)
> + return -1;
> + usleep_range(1000, 2000);
> + reg18g = phy_base_read(phydev, 18);
Please consider using phy_read_poll_timeout() instead of open coding
this busy waiting loop.
> + }
> +
> + return 0;
> +}
> +
> +/* bus->mdio_lock should be locked when using this function */
> +static int vsc8574_reset_lcpll(struct phy_device *phydev)
> +{
> + u16 reg_val = 0;
> + int ret = 0;
> +
> + phy_base_write(phydev, MSCC_EXT_PAGE_ACCESS,
> + MSCC_PHY_PAGE_EXTENDED_GPIO);
> +
> + /* Read LCPLL config vector into PRAM */
> + phy_base_write(phydev, 18, 0x8023);
> + ret = vsc8574_wait_for_micro_complete(phydev);
> + if (ret)
> + goto done;
It might make sense to write a helper function that encapsulates the:
- phy_base_write()
- wait_for_complete
pattern and use it throughout, with an option delay range argument so
you can put that in there, too.
--
Florian
