[U-Boot] [PATCH 1/1] ARM: DRA72x: fix io delay calibration for ethernet

[Nishanth Menon]

On 16:45-20150619, Mugunthan V N wrote:
> Ethernet on DRA72x EVM is not working as the io delay calibration
> value is not correct. Fixing this with the correct values and
> verified this on DRA72x EVM with tftp file transfer

This description is not entirely accurate. I propose the following:
we currently use in-development IODelay values for J6eco which are
proposed in the data sheet, however, DRA72x EVM uses DP83865 ethernet
Phy over RGMII. The PHY characteristics and routing choices made on
the EVM, make the current iodelay values fail ethernet communication.

Instead, we need to choose custom values for DRA72x-evm specifically
designed for the PHY and routing on the platform for ethernet to
function.


> 
> Cc: Nishanth Menon <nm at ti.com>
> Cc: Lokesh Vutla <lokeshvutla at ti.com>
> Signed-off-by: Mugunthan V N <mugunthanvnm at ti.com>
> ---
>  board/ti/dra7xx/mux_data.h | 48 +++++++++++++++++++++++-----------------------
>  1 file changed, 24 insertions(+), 24 deletions(-)
> 
> diff --git a/board/ti/dra7xx/mux_data.h b/board/ti/dra7xx/mux_data.h
> index c9301a5..0ca3c51 100644
> --- a/board/ti/dra7xx/mux_data.h
> +++ b/board/ti/dra7xx/mux_data.h
> @@ -156,30 +156,30 @@ const struct pad_conf_entry early_padconf[] = {
>  
>  #ifdef CONFIG_IODELAY_RECALIBRATION
>  const struct iodelay_cfg_entry iodelay_cfg_array[] = {
> -	{0x6F0, 480, 0}, /* RGMMI0_RXC_IN */
> -	{0x6FC, 111, 1641}, /* RGMMI0_RXCTL_IN */
> -	{0x708, 272, 1116}, /* RGMMI0_RXD0_IN */
> -	{0x714, 243, 1260}, /* RGMMI0_RXD1_IN */
> -	{0x720, 0, 1614}, /* RGMMI0_RXD2_IN */
> -	{0x72C, 105, 1673}, /* RGMMI0_RXD3_IN */
> -	{0x740, 531, 120}, /* RGMMI0_TXC_OUT */
> -	{0x74C, 11, 60}, /* RGMMI0_TXCTL_OUT */
> -	{0x758, 7, 120}, /* RGMMI0_TXD0_OUT */
> -	{0x764, 0, 0}, /* RGMMI0_TXD1_OUT */
> -	{0x770, 276, 120}, /* RGMMI0_TXD2_OUT */
> -	{0x77C, 440, 120}, /* RGMMI0_TXD3_OUT */
> -	{0xAB0, 702, 0}, /* CFG_VIN2A_D18_IN */
> -	{0xABC, 136, 976}, /* CFG_VIN2A_D19_IN */
> -	{0xAD4, 210, 1357}, /* CFG_VIN2A_D20_IN */
> -	{0xAE0, 189, 1462}, /* CFG_VIN2A_D21_IN */
> -	{0xAEC, 232, 1278}, /* CFG_VIN2A_D22_IN */
> -	{0xAF8, 0, 1397}, /* CFG_VIN2A_D23_IN */
> -	{0xA70, 1551, 115}, /* CFG_VIN2A_D12_OUT */
> -	{0xA7C, 816, 0}, /* CFG_VIN2A_D13_OUT */
> -	{0xA88, 876, 0}, /* CFG_VIN2A_D14_OUT */
> -	{0xA94, 312, 0}, /* CFG_VIN2A_D15_OUT */
> -	{0xAA0, 58, 0}, /* CFG_VIN2A_D16_OUT */
> -	{0xAAC, 0, 0}, /* CFG_VIN2A_D17_OUT */

Add a comment for custom values for J6-evm

> +	{0x6F0, 359, 0}, /* RGMMI0_RXC_IN */
> +	{0x6FC, 129, 1896}, /* RGMMI0_RXCTL_IN */
> +	{0x708, 80, 1391}, /* RGMMI0_RXD0_IN */
> +	{0x714, 196, 1522}, /* RGMMI0_RXD1_IN */
> +	{0x720, 40, 1860}, /* RGMMI0_RXD2_IN */
> +	{0x72C, 0, 1956}, /* RGMMI0_RXD3_IN */
> +	{0x740, 0, 220}, /* RGMMI0_TXC_OUT */
> +	{0x74C, 1820, 180}, /* RGMMI0_TXCTL_OUT */
> +	{0x758, 1740, 440}, /* RGMMI0_TXD0_OUT */
> +	{0x764, 1740, 240}, /* RGMMI0_TXD1_OUT */
> +	{0x770, 1680, 380}, /* RGMMI0_TXD2_OUT */
> +	{0x77C, 1740, 440}, /* RGMMI0_TXD3_OUT */

Comment here providing that these values are for u-boot using RGMII1
configuration on VIN2a_x pins.

> +	{0xAB0, 596, 0}, /* CFG_VIN2A_D18_IN */
> +	{0xABC, 314, 980}, /* CFG_VIN2A_D19_IN */
> +	{0xAD4, 241, 1536}, /* CFG_VIN2A_D20_IN */
> +	{0xAE0, 103, 1689}, /* CFG_VIN2A_D21_IN */
> +	{0xAEC, 161, 1563}, /* CFG_VIN2A_D22_IN */
> +	{0xAF8, 0, 1613}, /* CFG_VIN2A_D23_IN */
> +	{0xA70, 0, 200}, /* CFG_VIN2A_D12_OUT */
> +	{0xA7C, 1560, 140}, /* CFG_VIN2A_D13_OUT */
> +	{0xA88, 1700, 0}, /* CFG_VIN2A_D14_OUT */
> +	{0xA94, 1260, 0}, /* CFG_VIN2A_D15_OUT */
> +	{0xAA0, 1400, 0}, /* CFG_VIN2A_D16_OUT */
> +	{0xAAC, 1290, 0}, /* CFG_VIN2A_D17_OUT */
>  };
>  #endif
>  
Otherwise, the values look good. Along with the mentioned changes,
please feel free to Add:
Reviewed-by: Nishanth Menon <nm at ti.com>

-- 
Regards,
Nishanth Menon