Re: [PATCH v4] clk: imx: imx6sx: Allow a different LCDIF1 clock parent

[Abel Vesa <abel.vesa@linaro.org>]

On 23-08-15 10:09:23, Fabio Estevam wrote:
> From: Fabio Estevam <festevam@denx.de>
> 
> It is not a good idea to hardcode the LCDIF1 parent inside the
> clock driver because some users may want to use a different clock
> parent for LCDIF1. One of the reasons could be related to EMI tests.
> 
> Remove the harcoded LCDIF1 parent when the LCDIF1 parent is described
> via devicetree.
> 
> Old dtb's that do not describe the LCDIF1 parent via devicetree will
> use the same PLL5 clock as parent to keep the original behavior.
> 
> Signed-off-by: Fabio Estevam <festevam@denx.de>

Sorry, this hasn't made it to my clk-imx inbox due to linux-imx ML not
being CC'ed. My clk-imx inbox filters on my kernel.org email, the linux-clk
ML and the linux-imx ML.

Please use get_maintainer.pl script since that will also point to Peng Fan
who is a reviewer.

Patch looks good to me.

Reviewed-by: Abel Vesa <abel.vesa@linaro.org>

> ---
> Changes since v3:
> - Check for the presence of 'assigned-clock-parents'. (Stephen)
> 
>  drivers/clk/imx/clk-imx6sx.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/clk/imx/clk-imx6sx.c b/drivers/clk/imx/clk-imx6sx.c
> index 3f1502933e59..69f8f6f9ca49 100644
> --- a/drivers/clk/imx/clk-imx6sx.c
> +++ b/drivers/clk/imx/clk-imx6sx.c
> @@ -121,6 +121,7 @@ static void __init imx6sx_clocks_init(struct device_node *ccm_node)
>  {
>  	struct device_node *np;
>  	void __iomem *base;
> +	bool lcdif1_assigned_clk;
>  
>  	clk_hw_data = kzalloc(struct_size(clk_hw_data, hws,
>  					  IMX6SX_CLK_CLK_END), GFP_KERNEL);
> @@ -498,9 +499,16 @@ static void __init imx6sx_clocks_init(struct device_node *ccm_node)
>  	clk_set_parent(hws[IMX6SX_CLK_EIM_SLOW_SEL]->clk, hws[IMX6SX_CLK_PLL2_PFD2]->clk);
>  	clk_set_rate(hws[IMX6SX_CLK_EIM_SLOW]->clk, 132000000);
>  
> -	/* set parent clock for LCDIF1 pixel clock */
> -	clk_set_parent(hws[IMX6SX_CLK_LCDIF1_PRE_SEL]->clk, hws[IMX6SX_CLK_PLL5_VIDEO_DIV]->clk);
> -	clk_set_parent(hws[IMX6SX_CLK_LCDIF1_SEL]->clk, hws[IMX6SX_CLK_LCDIF1_PODF]->clk);
> +	np = of_find_node_by_path("/soc/bus@2200000/spba-bus@2240000/lcdif@2220000");
> +	lcdif1_assigned_clk = of_find_property(np, "assigned-clock-parents", NULL);
> +
> +	/* Set parent clock for LCDIF1 pixel clock if not done via devicetree */
> +	if (!lcdif1_assigned_clk) {
> +		clk_set_parent(hws[IMX6SX_CLK_LCDIF1_PRE_SEL]->clk,
> +			       hws[IMX6SX_CLK_PLL5_VIDEO_DIV]->clk);
> +		clk_set_parent(hws[IMX6SX_CLK_LCDIF1_SEL]->clk,
> +			       hws[IMX6SX_CLK_LCDIF1_PODF]->clk);
> +	}
>  
>  	/* Set the parent clks of PCIe lvds1 and pcie_axi to be pcie ref, axi */
>  	if (clk_set_parent(hws[IMX6SX_CLK_LVDS1_SEL]->clk, hws[IMX6SX_CLK_PCIE_REF_125M]->clk))
> -- 
> 2.34.1
> 
>