[PATCH 2/2] clk: stm32f: fix setting of LCD clock

[Patrice CHOTARD]

On 11/11/23 11:46, Dario Binacchi wrote:
> Set pllsaidivr only if the PLLSAIR output frequency is an exact multiple
> of the pixel clock rate. Otherwise, we search through all combinations
> of pllsaidivr * pllsair and use the one which gives the rate closest to
> requested one.
> 
> Fixes: 5e993508cb25 ("clk: clk_stm32f: Add set_rate for LTDC clock")
> Signed-off-by: Dario Binacchi <dario.binacchi at amarulasolutions.com>
> 
> ---
> 
>  drivers/clk/stm32/clk-stm32f.c | 26 ++++++++++++++------------
>  1 file changed, 14 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/clk/stm32/clk-stm32f.c b/drivers/clk/stm32/clk-stm32f.c
> index 4c1864193357..d68c75ed2013 100644
> --- a/drivers/clk/stm32/clk-stm32f.c
> +++ b/drivers/clk/stm32/clk-stm32f.c
> @@ -522,18 +522,20 @@ static ulong stm32_set_rate(struct clk *clk, ulong rate)
>  
>  	/* get the current PLLSAIR output freq */
>  	pllsair_rate = stm32_clk_get_pllsai_rate(priv, PLLSAIR);
> -	best_div = pllsair_rate / rate;
> -
> -	/* look into pllsaidivr_table if this divider is available*/
> -	for (i = 0 ; i < sizeof(pllsaidivr_table); i++)
> -		if (best_div == pllsaidivr_table[i]) {
> -			/* set pll_saidivr with found value */
> -			clrsetbits_le32(&regs->dckcfgr,
> -					RCC_DCKCFGR_PLLSAIDIVR_MASK,
> -					pllsaidivr_table[i] <<
> -					RCC_DCKCFGR_PLLSAIDIVR_SHIFT);
> -			return rate;
> -		}
> +	if ((pllsair_rate % rate) == 0) {
> +		best_div = pllsair_rate / rate;
> +
> +		/* look into pllsaidivr_table if this divider is available */
> +		for (i = 0 ; i < sizeof(pllsaidivr_table); i++)
> +			if (best_div == pllsaidivr_table[i]) {
> +				/* set pll_saidivr with found value */
> +				clrsetbits_le32(&regs->dckcfgr,
> +						RCC_DCKCFGR_PLLSAIDIVR_MASK,
> +						pllsaidivr_table[i] <<
> +						RCC_DCKCFGR_PLLSAIDIVR_SHIFT);
> +				return rate;
> +			}
> +	}
>  
>  	/*
>  	 * As no pllsaidivr value is suitable to obtain requested freq,

Reviewed-by: Patrice Chotard <patrice.chotard at foss.st.com>
Thanks
Patrice