Re: [RESEND v1] clk: imx95-blk-ctl: Fix REFCLK rise-fall mismatch on i.MX95

[Frank Li]

On Thu, Jul 30, 2026 at 05:04:47PM +0800, hongxing.zhu@xxxxxxxxxxx wrote:
> From: Richard Zhu <hongxing.zhu@xxxxxxx>
>
> When the internal PLL is used as the PCIe reference clock source on i.MX95,
> a REFCLK rise-fall time mismatch is observed during PCIe Gen1 compliance
> testing with the Lfast IO analyzer.
>
> Fix this issue by configuring the IREF_TX field to 0xF (15), which adjusts
> the transmitter current reference to meet the PCIe specification timing
> requirements.
>
> Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
> Reviewed-by: Peng Fan <peng.fan@xxxxxxx>
> ---

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>

>  drivers/clk/imx/clk-imx95-blk-ctl.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/drivers/clk/imx/clk-imx95-blk-ctl.c b/drivers/clk/imx/clk-imx95-blk-ctl.c
> index 1f9259f456079..bc6957299ceca 100644
> --- a/drivers/clk/imx/clk-imx95-blk-ctl.c
> +++ b/drivers/clk/imx/clk-imx95-blk-ctl.c
> @@ -44,6 +44,8 @@ struct imx95_blk_ctl_clk_dev_data {
>  	const char * const *parent_names;
>  	u32 num_parents;
>  	u32 reg;
> +	u32 reg_init_msk;
> +	u32 reg_init_val;
>  	u32 bit_idx;
>  	u32 bit_width;
>  	u32 clk_type;
> @@ -289,6 +291,8 @@ static const struct imx95_blk_ctl_clk_dev_data hsio_blk_ctl_clk_dev_data[] = {
>  		.parent_names = (const char *[]){ "func_out_en", },
>  		.num_parents = 1,
>  		.reg = 0,
> +		.reg_init_msk = GENMASK(10, 7),
> +		.reg_init_val = GENMASK(10, 7),
>  		.bit_idx = 6,
>  		.bit_width = 1,
>  		.type = CLK_GATE,
> @@ -410,6 +414,9 @@ static int imx95_bc_probe(struct platform_device *pdev)
>  		const struct imx95_blk_ctl_clk_dev_data *data = &bc->pdata->clk_dev_data[i];
>  		void __iomem *reg = base + data->reg;
>
> +		if (data->reg_init_msk)
> +			writel((readl(reg) & ~data->reg_init_msk) | data->reg_init_val, reg);
> +
>  		if (data->type == CLK_MUX) {
>  			hws[i] = clk_hw_register_mux(dev, data->name, data->parent_names,
>  						     data->num_parents, data->flags, reg,
> --
> 2.34.1
>
>