Hi Maxime
On Thu, 10 Dec 2020 at 13:47, Maxime Ripard <maxime@xxxxxxxxxx> wrote:
>
> As part of the enable sequence we might change the HSM clock rate if the
> pixel rate is different than the one we were already dealing with.
>
> On the BCM2835 however, the CEC clock derives from the HSM clock so any
> rate change will need to be reflected in the CEC clock divider to output
> 40kHz.
>
> Fixes: cd4cb49dc5bb ("drm/vc4: hdmi: Adjust HSM clock rate depending on pixel rate")
> Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
I thought we'd got a duplicate patch here, but it's moving code that
was changed in patch 6/15 so it can be called from
vc4_hdmi_encoder_pre_crtc_configure too. Good for confusing me!
Reviewed-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/vc4/vc4_hdmi.c | 39 +++++++++++++++++++++++++---------
> 1 file changed, 29 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index 0c53d7427d15..b93ee3e26e2b 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -132,6 +132,27 @@ static void vc5_hdmi_reset(struct vc4_hdmi *vc4_hdmi)
> HDMI_READ(HDMI_CLOCK_STOP) | VC4_DVP_HT_CLOCK_STOP_PIXEL);
> }
>
> +#ifdef CONFIG_DRM_VC4_HDMI_CEC
> +static void vc4_hdmi_cec_update_clk_div(struct vc4_hdmi *vc4_hdmi)
> +{
> + u16 clk_cnt;
> + u32 value;
> +
> + value = HDMI_READ(HDMI_CEC_CNTRL_1);
> + value &= ~VC4_HDMI_CEC_DIV_CLK_CNT_MASK;
> +
> + /*
> + * Set the clock divider: the hsm_clock rate and this divider
> + * setting will give a 40 kHz CEC clock.
> + */
> + clk_cnt = clk_get_rate(vc4_hdmi->hsm_clock) / CEC_CLOCK_FREQ;
> + value |= clk_cnt << VC4_HDMI_CEC_DIV_CLK_CNT_SHIFT;
> + HDMI_WRITE(HDMI_CEC_CNTRL_1, value);
> +}
> +#else
> +static void vc4_hdmi_cec_update_clk_div(struct vc4_hdmi *vc4_hdmi) {}
> +#endif
> +
> static enum drm_connector_status
> vc4_hdmi_connector_detect(struct drm_connector *connector, bool force)
> {
> @@ -761,6 +782,8 @@ static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
> return;
> }
>
> + vc4_hdmi_cec_update_clk_div(vc4_hdmi);
> +
> /*
> * FIXME: When the pixel freq is 594MHz (4k60), this needs to be setup
> * at 300MHz.
> @@ -1586,7 +1609,6 @@ static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi)
> {
> struct cec_connector_info conn_info;
> struct platform_device *pdev = vc4_hdmi->pdev;
> - u16 clk_cnt;
> u32 value;
> int ret;
>
> @@ -1605,17 +1627,14 @@ static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi)
> cec_s_conn_info(vc4_hdmi->cec_adap, &conn_info);
>
> HDMI_WRITE(HDMI_CEC_CPU_MASK_SET, 0xffffffff);
> +
> value = HDMI_READ(HDMI_CEC_CNTRL_1);
> - value &= ~VC4_HDMI_CEC_DIV_CLK_CNT_MASK;
> - /*
> - * Set the logical address to Unregistered and set the clock
> - * divider: the hsm_clock rate and this divider setting will
> - * give a 40 kHz CEC clock.
> - */
> - clk_cnt = clk_get_rate(vc4_hdmi->hsm_clock) / CEC_CLOCK_FREQ;
> - value |= VC4_HDMI_CEC_ADDR_MASK |
> - (clk_cnt << VC4_HDMI_CEC_DIV_CLK_CNT_SHIFT);
> + /* Set the logical address to Unregistered */
> + value |= VC4_HDMI_CEC_ADDR_MASK;
> HDMI_WRITE(HDMI_CEC_CNTRL_1, value);
> +
> + vc4_hdmi_cec_update_clk_div(vc4_hdmi);
> +
> ret = devm_request_threaded_irq(&pdev->dev, platform_get_irq(pdev, 0),
> vc4_cec_irq_handler,
> vc4_cec_irq_handler_thread, 0,
> --
> 2.28.0
>
