Re: [PATCH] clk: rs9: fix wrong default value for clock amplitude

From: POPESCU Catalin
Date: Mon Apr 15 2024 - 08:44:24 EST


I'm sorry, I forgot to add v2 in the title.

On 15/04/2024 14:42, Catalin Popescu wrote:
> According to 9FGV0241, 9FGV0441 & 9FGV0841 datasheets, the default
> value for the clock amplitude is 0.8V, while the driver assumes 0.7V.
>
> Additionally, define constants for default values for both clock
> amplitude and spread spectrum and use them.
>
> Fixes: 892e0ddea1aa ("clk: rs9: Add Renesas 9-series PCIe clock generator driver")
>
> Signed-off-by: Catalin Popescu <catalin.popescu@xxxxxxxxxxxxxxxxxxxx>
> ---
> Changes in v2:
> - update commit message with "9FGV0841", document change about spread
> spectrum and add Fixes tag.
> ---
> drivers/clk/clk-renesas-pcie.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/clk/clk-renesas-pcie.c b/drivers/clk/clk-renesas-pcie.c
> index 53e21ac302e6..4c3a5e4eb77a 100644
> --- a/drivers/clk/clk-renesas-pcie.c
> +++ b/drivers/clk/clk-renesas-pcie.c
> @@ -25,10 +25,12 @@
> #define RS9_REG_SS_AMP_0V7 0x1
> #define RS9_REG_SS_AMP_0V8 0x2
> #define RS9_REG_SS_AMP_0V9 0x3
> +#define RS9_REG_SS_AMP_DEFAULT RS9_REG_SS_AMP_0V8
> #define RS9_REG_SS_AMP_MASK 0x3
> #define RS9_REG_SS_SSC_100 0
> #define RS9_REG_SS_SSC_M025 (1 << 3)
> #define RS9_REG_SS_SSC_M050 (3 << 3)
> +#define RS9_REG_SS_SSC_DEFAULT RS9_REG_SS_SSC_100
> #define RS9_REG_SS_SSC_MASK (3 << 3)
> #define RS9_REG_SS_SSC_LOCK BIT(5)
> #define RS9_REG_SR 0x2
> @@ -205,8 +207,8 @@ static int rs9_get_common_config(struct rs9_driver_data *rs9)
> int ret;
>
> /* Set defaults */
> - rs9->pll_amplitude = RS9_REG_SS_AMP_0V7;
> - rs9->pll_ssc = RS9_REG_SS_SSC_100;
> + rs9->pll_amplitude = RS9_REG_SS_AMP_DEFAULT;
> + rs9->pll_ssc = RS9_REG_SS_SSC_DEFAULT;
>
> /* Output clock amplitude */
> ret = of_property_read_u32(np, "renesas,out-amplitude-microvolt",
> @@ -247,13 +249,13 @@ static void rs9_update_config(struct rs9_driver_data *rs9)
> int i;
>
> /* If amplitude is non-default, update it. */
> - if (rs9->pll_amplitude != RS9_REG_SS_AMP_0V7) {
> + if (rs9->pll_amplitude != RS9_REG_SS_AMP_DEFAULT) {
> regmap_update_bits(rs9->regmap, RS9_REG_SS, RS9_REG_SS_AMP_MASK,
> rs9->pll_amplitude);
> }
>
> /* If SSC is non-default, update it. */
> - if (rs9->pll_ssc != RS9_REG_SS_SSC_100) {
> + if (rs9->pll_ssc != RS9_REG_SS_SSC_DEFAULT) {
> regmap_update_bits(rs9->regmap, RS9_REG_SS, RS9_REG_SS_SSC_MASK,
> rs9->pll_ssc);
> }
>
> base-commit: 6bd343537461b57f3efe5dfc5fc193a232dfef1e
> prerequisite-patch-id: 0000000000000000000000000000000000000000