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

[Peng Fan]

Hi Richard,

> Subject: [PATCH v1] clk: imx95-blk-ctl: Fix REFCLK rise-fall mismatch on
> i.MX95
> 
> 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.

BLK CTRL in HSIOMIX should be save/restore for the settings you configured
in probe phase.

Regards
Peng.

> 
> Signed-off-by: Richard Zhu <hongxing.zhu@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 1f9259f45607..bc6957299cec 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,
> --
> 2.37.1