Re: [PATCH v3 11/15] media: qcom: camss: Functionally decompose CSIPHY clock lookups

Konrad Dybcio
2023-08-26T10:14:06Z

On 23.08.2023 12:44, Bryan O'Donoghue wrote:
> The csiphyX_timer and csiX_phy values need not be hard-coded. We can
> functionally decompose the string matching inside of a loop.
>
> Static string values are brittle, difficult to extend and not required
> anyway since the camss->res->csiphy_num value informs us of the number
> of CSIPHYs and hence the set of potential clocks for a given CSIPHY.
>
> In simple terms if we have five CSIPHYs we can have no more and no less
> than five csiphy_timer clocks. Similarly csi_phy core clocks have a 1:1
> relationship with the PHY they clock.
>
> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
> ---
> .../media/platform/qcom/camss/camss-csiphy.c | 37 ++++++++++++-------
> 1 file changed, 23 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/media/platform/qcom/camss/camss-csiphy.c b/drivers/media/platform/qcom/camss/camss-csiphy.c
> index 0e8c2a59ea241..baf78c525fbfc 100644
> --- a/drivers/media/platform/qcom/camss/camss-csiphy.c
> +++ b/drivers/media/platform/qcom/camss/camss-csiphy.c
> @@ -536,6 +536,15 @@ static int csiphy_init_formats(struct v4l2_subdev *sd,
> return csiphy_set_format(sd, fh ? fh->state : NULL, &format);
> }
>
> +static bool csiphy_match_clock_name(const char *clock_name, const char *format,
> + int index)
> +{
> + char name[CAMSS_RES_MAX];
similar comment to the previous patch about the buf size

> +
> + snprintf(name, sizeof(name), format, index);
> + return !strcmp(clock_name, name);
> +}
> +
> /*
> * msm_csiphy_subdev_init - Initialize CSIPHY device structure and resources
> * @csiphy: CSIPHY device
> @@ -550,7 +559,7 @@ int msm_csiphy_subdev_init(struct camss *camss,
> {
> struct device *dev = camss->dev;
> struct platform_device *pdev = to_platform_device(dev);
> - int i, j;
> + int i, j, k;
> int ret;
>
> csiphy->camss = camss;
> @@ -666,19 +675,19 @@ int msm_csiphy_subdev_init(struct camss *camss,
> for (j = 0; j < clock->nfreqs; j++)
> clock->freq[j] = res->clock_rate[i][j];
>
> - if (!strcmp(clock->name, "csiphy0_timer") ||
> - !strcmp(clock->name, "csiphy1_timer") ||
> - !strcmp(clock->name, "csiphy2_timer") ||
> - !strcmp(clock->name, "csiphy3_timer") ||
> - !strcmp(clock->name, "csiphy4_timer") ||
> - !strcmp(clock->name, "csiphy5_timer"))
> - csiphy->rate_set[i] = true;
> -
> - if (camss->res->version == CAMSS_660 &&
> - (!strcmp(clock->name, "csi0_phy") ||
> - !strcmp(clock->name, "csi1_phy") ||
> - !strcmp(clock->name, "csi2_phy")))
> - csiphy->rate_set[i] = true;
> + for (k = 0; k < camss->res->csiphy_num; k++) {
> + csiphy->rate_set[i] = csiphy_match_clock_name(clock->name,
> + "csiphy%d_timer", k);
This entire functions is like.. soooo over-engineered

adding something like csiphy_timer_clks and cisphy_clks and stuff
would make this string comparison mess unnecessary

> + if (csiphy->rate_set[i])
> + break;
> +
> + if (camss->res->version == CAMSS_660) {
> + csiphy->rate_set[i] = csiphy_match_clock_name(clock->name,
> + "csi%d_phy", k);
hm, only ratesetting on 660 sounds very sus

Konrad