Re: [PATCH 2/3] net: ethernet: add c45 PHY support in MDIO read/write functions.

From: Andrew Lunn
Date: Sat Feb 23 2019 - 10:25:48 EST


On Fri, Feb 22, 2019 at 08:12:42PM +0000, Parshuram Thombare wrote:
> This patch modify MDIO read/write functions to support
> communication with C45 PHY in Cadence ethernet controller driver.
>
> Signed-off-by: Parshuram Thombare <pthombar@xxxxxxxxxxx>
> ---
> drivers/net/ethernet/cadence/macb.h | 15 +++++--
> drivers/net/ethernet/cadence/macb_main.c | 61 ++++++++++++++++++++++++-----
> 2 files changed, 61 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
> index bed4ded..59c23e0 100644
> --- a/drivers/net/ethernet/cadence/macb.h
> +++ b/drivers/net/ethernet/cadence/macb.h
> @@ -636,10 +636,17 @@
> #define GEM_CLK_DIV96 5
>
> /* Constants for MAN register */
> -#define MACB_MAN_SOF 1
> -#define MACB_MAN_WRITE 1
> -#define MACB_MAN_READ 2
> -#define MACB_MAN_CODE 2
> +#define MACB_MAN_C22_SOF 1
> +#define MACB_MAN_C22_WRITE 1
> +#define MACB_MAN_C22_READ 2
> +#define MACB_MAN_C22_CODE 2
> +
> +#define MACB_MAN_C45_SOF 0
> +#define MACB_MAN_C45_ADDR 0
> +#define MACB_MAN_C45_WRITE 1
> +#define MACB_MAN_C45_POST_READ_INCR 2
> +#define MACB_MAN_C45_READ 3
> +#define MACB_MAN_C45_CODE 2
>
> /* Capability mask bits */
> #define MACB_CAPS_ISR_CLEAR_ON_WRITE 0x00000001
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index 4f4f8e5..2494abf 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -323,11 +323,30 @@ static int macb_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
> struct macb *bp = bus->priv;
> int value;
>
> - macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
> - | MACB_BF(RW, MACB_MAN_READ)
> - | MACB_BF(PHYA, mii_id)
> - | MACB_BF(REGA, regnum)
> - | MACB_BF(CODE, MACB_MAN_CODE)));
> + if (regnum & MII_ADDR_C45) {
> + macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_C45_SOF)
> + | MACB_BF(RW, MACB_MAN_C45_ADDR)
> + | MACB_BF(PHYA, mii_id)
> + | MACB_BF(REGA, (regnum >> 16) & 0x1F)
> + | MACB_BF(DATA, regnum & 0xFFFF)
> + | MACB_BF(CODE, MACB_MAN_C45_CODE)));
> +
> + /* wait for end of transfer */
> + while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
> + cpu_relax();

You need a timeout here, and anywhere you wait for the hardware to
complete. Try to make use of readx_poll_timeout() variants.

Andrew