Re: [PATCH 08/37] clk: renesas: rzg2l: trust value returned by hardware

[Sergey Shtylyov]

On 9/12/23 7:51 AM, Claudiu wrote:

> From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
> 
> Initial value of CPG_PL2SDHI_DSEL bits 0..1 or 4..6 is 01b. Hardware user's
> manual (r01uh0914ej0130-rzg2l-rzg2lc.pdf) specifies that setting 0 is
> prohibited. The rzg2l_cpg_sd_clk_mux_get_parent() should just read
> CPG_PL2SDHI_DSEL, trust the value and return the proper clock parent index
> based on the read value. Do this.
> 
> Fixes: eaff33646f4cb ("clk: renesas: rzg2l: Add SDHI clk mux support")
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
> ---
>  drivers/clk/renesas/rzg2l-cpg.c | 8 +-------
>  1 file changed, 1 insertion(+), 7 deletions(-)
> 
> diff --git a/drivers/clk/renesas/rzg2l-cpg.c b/drivers/clk/renesas/rzg2l-cpg.c
> index 1195d4b1f545..d0d086d6dc51 100644
> --- a/drivers/clk/renesas/rzg2l-cpg.c
> +++ b/drivers/clk/renesas/rzg2l-cpg.c
> @@ -239,14 +239,8 @@ static u8 rzg2l_cpg_sd_clk_mux_get_parent(struct clk_hw *hw)
>  
>  	val >>= GET_SHIFT(hwdata->conf);
>  	val &= GENMASK(GET_WIDTH(hwdata->conf) - 1, 0);
> -	if (val) {
> -		val--;
> -	} else {
> -		/* Prohibited clk source, change it to 533 MHz(reset value) */
> -		rzg2l_cpg_sd_clk_mux_set_parent(hw, 0);
> -	}
>  
> -	return val;
> +	return val ? --val : val;

	return val ? val - 1 : 0;