[U-Boot] [PATCH] am33xx: Stop modifying certain EMIF4D registers

[Vaibhav Bedia]

Hi Tom,

On Thu, Nov 7, 2013 at 11:42 AM, Tom Rini <trini at ti.com> wrote:
> Based on the definitive guide to EMIF configuration[1] certain registers
> that we have been modifying (and are documented registers) should be
> left in their reset values rather than modified.  This has been tested
> on AM335x GP EVM and Beaglebone White.
>

[...]

> diff --git a/board/ti/ti814x/evm.c b/board/ti/ti814x/evm.c
> index e406326..0b76a77 100644
> --- a/board/ti/ti814x/evm.c
> +++ b/board/ti/ti814x/evm.c
> @@ -33,15 +33,12 @@ static struct ctrl_dev *cdev = (struct ctrl_dev *)CTRL_DEVICE_BASE;
>  #ifdef CONFIG_SPL_BUILD
>  static const struct cmd_control evm_ddr2_cctrl_data = {
>         .cmd0csratio    = 0x80,
> -       .cmd0dldiff     = 0x04,
>         .cmd0iclkout    = 0x00,
>
>         .cmd1csratio    = 0x80,
> -       .cmd1dldiff     = 0x04,
>         .cmd1iclkout    = 0x00,
>
>         .cmd2csratio    = 0x80,
> -       .cmd2dldiff     = 0x04,
>         .cmd2iclkout    = 0x00,
>  };
>
> @@ -77,8 +74,6 @@ static const struct ddr_data evm_ddr2_data = {
>         .datagiratio0           = ((0<<10) | (0<<0)),
>         .datafwsratio0          = ((0x90<<10) | (0x90<<0)),
>         .datawrsratio0          = ((0x50<<10) | (0x50<<0)),
> -       .datauserank0delay      = 1,
> -       .datadldiff0            = 0x4,
>  };
>
>  void set_uart_mux_conf(void)
> diff --git a/board/ti/ti816x/evm.c b/board/ti/ti816x/evm.c
> index 74d35e9..a53859e 100644
> --- a/board/ti/ti816x/evm.c
> +++ b/board/ti/ti816x/evm.c
> @@ -59,21 +59,16 @@ static struct ddr_data ddr2_data = {
>         .datagiratio0           = ((0x0<<10) | (0x0<<0)),
>         .datafwsratio0          = ((0x13A<<10) | (0x13A<<0)),
>         .datawrsratio0          = ((0x8A<<10) | (0x8A<<0)),
> -       .datauserank0delay      = 0x1,
> -       .datadldiff0            = 0x0, /* depend on cpu rev, set later */
>  };
>
>  static struct cmd_control ddr2_ctrl = {
>         .cmd0csratio    = 0x80,
> -       .cmd0dldiff     = 0x04, /* reset value is 0x4 */
>         .cmd0iclkout    = 0x00,
>
>         .cmd1csratio    = 0x80,
> -       .cmd1dldiff     = 0x04, /* reset value is 0x4 */
>         .cmd1iclkout    = 0x00,
>
>         .cmd2csratio    = 0x80,
> -       .cmd2dldiff     = 0x04, /* reset value is 0x4 */
>         .cmd2iclkout    = 0x00,
>
>  };
> @@ -150,21 +145,16 @@ static struct ddr_data ddr3_data = {
>         .datagiratio0           = ((0x20<<10) | 0x20<<0),
>         .datafwsratio0          = ((RD_DQS_GATE<<10) | (RD_DQS_GATE<<0)),
>         .datawrsratio0          = (((WR_DQS+0x40)<<10) | ((WR_DQS+0x40)<<0)),
> -       .datauserank0delay      = 0x1,
> -       .datadldiff0            = 0x0, /* depend on cpu rev, set later */
>  };
>
>  static const struct cmd_control ddr3_ctrl = {
>         .cmd0csratio    = 0x100,
> -       .cmd0dldiff     = 0x004, /* reset value is 0x4 */
>         .cmd0iclkout    = 0x001,
>
>         .cmd1csratio    = 0x100,
> -       .cmd1dldiff     = 0x004, /* reset value is 0x4 */
>         .cmd1iclkout    = 0x001,
>
>         .cmd2csratio    = 0x100,
> -       .cmd2dldiff     = 0x004, /* reset value is 0x4 */
>         .cmd2iclkout    = 0x001,
>  };
>
> @@ -198,11 +188,6 @@ void sdram_init(void)
>         config_dmm(&evm_lisa_map_regs);
>
>  #ifdef CONFIG_TI816X_EVM_DDR2
> -       ddr2_data.datadldiff0 = (get_cpu_rev() == 0x1 ? 0x0 : 0xF);
> -       ddr2_ctrl.cmd0dldiff = (get_cpu_rev() == 0x1 ? 0x0 : 0xF);
> -       ddr2_ctrl.cmd1dldiff = (get_cpu_rev() == 0x1 ? 0x0 : 0xF);
> -       ddr2_ctrl.cmd2dldiff = (get_cpu_rev() == 0x1 ? 0x0 : 0xF);
> -
>         if (CONFIG_TI816X_USE_EMIF0) {
>                 ddr2_emif0_regs.emif_ddr_phy_ctlr_1 =
>                         (get_cpu_rev() == 0x1 ? 0x0000010B : 0x0000030B);
> @@ -217,8 +202,6 @@ void sdram_init(void)
>  #endif
>
>  #ifdef CONFIG_TI816X_EVM_DDR3
> -       ddr3_data.datadldiff0 = (get_cpu_rev() == 0x1 ? 0x0 : 0xF);
> -