On 07.12.23 15:16, Dario Binacchi wrote:
> The patch completes the setting of CLKLANE_STOP for the imx8mn and imx8mp
> platforms (i. e. not exynos).
This also affects i.MX8MM, so better just mention i.MX in general in the
commit message.
>
> Co-developed-by: Michael Trimarchi <michael@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Michael Trimarchi <michael@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Dario Binacchi <dario.binacchi@xxxxxxxxxxxxxxxxxxxx>
> ---
>
> (no changes since v1)
>
> drivers/gpu/drm/bridge/samsung-dsim.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
> index 15bf05b2bbe4..13f181c99d7e 100644
> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
> @@ -96,6 +96,7 @@
> #define DSIM_MFLUSH_VS BIT(29)
> /* This flag is valid only for exynos3250/3472/5260/5430 */
> #define DSIM_CLKLANE_STOP BIT(30)
> +#define DSIM_NON_CONTINUOUS_CLKLANE BIT(31)
>
> /* DSIM_ESCMODE */
> #define DSIM_TX_TRIGGER_RST BIT(4)
> @@ -945,8 +946,12 @@ static int samsung_dsim_init_link(struct samsung_dsim *dsi)
> * power consumption.
> */
> if (driver_data->has_clklane_stop &&
> - dsi->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS)
> + dsi->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) {
> + if (!samsung_dsim_hw_is_exynos(dsi->plat_data->hw_type))
> + reg |= DSIM_NON_CONTINUOUS_CLKLANE;
> +
> reg |= DSIM_CLKLANE_STOP;
> + }
I really wonder what the difference between DSIM_NON_CONTINUOUS_CLKLANE
and DSIM_CLKLANE_STOP is.
If Exynos only has the latter, it's pretty clear what to use. But as
i.MX has both of these bits, should both be set? Or is setting
DSIM_NON_CONTINUOUS_CLKLANE enough and we should leave DSIM_CLKLANE_STOP
alone?
Maybe someone has a clue here. The description of the bits in the RM is:
DSIM_NON_CONTINUOUS_CLKLANE - Non-continuous clock mode
DSIM_CLKLANE_STOP - PHY clock lane On/Off for ESD
> samsung_dsim_write(dsi, DSIM_CONFIG_REG, reg);
>
> lanes_mask = BIT(dsi->lanes) - 1;
