[U-Boot] [PATCH] mx6qsabreauto: Fix the EIM clock for the mx6qp variant

[Stefano Babic]

On 27/12/2016 02:04, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam at nxp.com>
> 
> On the MX6Q the aclk_eim_slow_podf field is '1' after POR, while on the
> MX6DQP it is '3'.
> 
> This makes the EIM clock to be only 66MHz on the mx6qp variant, instead of
> 132 MHz.
> 
> Instead of relying on the POR values for the CSMR1 register, make sure to
> manually configure the clk_eim_slow_sel field as '00' so that EIM clock is
> derived from AXI clock and the aclk_eim_slow_podf field as '1' so that EIM
> clock can be AXI clock divided by 2.
> 
> This way a consistent EIM clock frequency is configured for all the mx6
> variants.
> 
> Signed-off-by: Fabio Estevam <fabio.estevam at nxp.com>
> ---
>  board/freescale/mx6qsabreauto/mx6qsabreauto.c | 28 +++++++++++++++++++++++++++
>  1 file changed, 28 insertions(+)
> 
> diff --git a/board/freescale/mx6qsabreauto/mx6qsabreauto.c b/board/freescale/mx6qsabreauto/mx6qsabreauto.c
> index 5fca4d1..51bbbc4 100644
> --- a/board/freescale/mx6qsabreauto/mx6qsabreauto.c
> +++ b/board/freescale/mx6qsabreauto/mx6qsabreauto.c
> @@ -231,6 +231,33 @@ static void eimnor_cs_setup(void)
>  	set_chipselect_size(CS0_128);
>  }
>  
> +static void eim_clk_setup(void)
> +{
> +	struct mxc_ccm_reg *imx_ccm = (struct mxc_ccm_reg *)CCM_BASE_ADDR;
> +	int cscmr1, ccgr6;
> +
> +
> +	/* Turn off EIM clock */
> +	ccgr6 = readl(&imx_ccm->CCGR6);
> +	ccgr6 &= ~(0x3 << 10);
> +	writel(ccgr6, &imx_ccm->CCGR6);
> +
> +	/*
> +	 * Configure clk_eim_slow_sel = 00 --> derive clock from AXI clk root
> +	 * and aclk_eim_slow_podf = 01 --> divide by 2
> +	 * so that we can have EIM at the maximum clock of 132MHz
> +	 */
> +	cscmr1 = readl(&imx_ccm->cscmr1);
> +	cscmr1 &= ~(MXC_CCM_CSCMR1_ACLK_EMI_SLOW_MASK |
> +		    MXC_CCM_CSCMR1_ACLK_EMI_SLOW_PODF_MASK);
> +	cscmr1 |= (1 << MXC_CCM_CSCMR1_ACLK_EMI_SLOW_PODF_OFFSET);
> +	writel(cscmr1, &imx_ccm->cscmr1);
> +
> +	/* Turn on EIM clock */
> +	ccgr6 |= (0x3 << 10);
> +	writel(ccgr6, &imx_ccm->CCGR6);
> +}
> +
>  static void setup_iomux_eimnor(void)
>  {
>  	imx_iomux_v3_setup_multiple_pads(eimnor_pads, ARRAY_SIZE(eimnor_pads));
> @@ -519,6 +546,7 @@ int board_early_init_f(void)
>  #ifdef CONFIG_NAND_MXS
>  	setup_gpmi_nand();
>  #endif
> +	eim_clk_setup();
>  
>  	return 0;
>  }
> 

Applied to u-boot-imx, -master, thanks !

Best regards,
Stefano Babic


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