diff options
| author | Maxime Ripard <maxime@cerno.tech> | 2021-01-11 15:23:00 +0100 |
|---|---|---|
| committer | Maxime Ripard <maxime@cerno.tech> | 2021-01-28 10:28:27 +0100 |
| commit | f1ceb9d10043683b89e5e5e5848fb4e855295762 (patch) | |
| tree | 95fccc576a4221a66bde6c5caa843202902a363e /drivers/gpu/drm/vc4 | |
| parent | b06eecb5158e5f3eb47b9d05aea8c259985cc5f7 (diff) | |
drm/vc4: hdmi: Compute the CEC clock divider from the clock rate
The CEC clock divider needs to output a frequency of 40kHz from the HSM
rate on the BCM2835. The driver used to have a fixed frequency for it,
but that changed for the BCM2711 and we now need to compute it
dynamically to maintain the proper rate.
Fixes: cd4cb49dc5bb ("drm/vc4: hdmi: Adjust HSM clock rate depending on pixel rate")
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Tested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://patchwork.freedesktop.org/patch/msgid/20210111142309.193441-7-maxime@cerno.tech
Diffstat (limited to 'drivers/gpu/drm/vc4')
| -rw-r--r-- | drivers/gpu/drm/vc4/vc4_hdmi.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index c3a301396aad..50008513edfc 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -1598,6 +1598,7 @@ 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; @@ -1623,8 +1624,9 @@ static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi) * 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 | - (4091 << VC4_HDMI_CEC_DIV_CLK_CNT_SHIFT); + (clk_cnt << VC4_HDMI_CEC_DIV_CLK_CNT_SHIFT); HDMI_WRITE(HDMI_CEC_CNTRL_1, value); ret = devm_request_threaded_irq(&pdev->dev, platform_get_irq(pdev, 0), vc4_cec_irq_handler, |