From: Maxime Ripard maxime@cerno.tech
[ Upstream commit 163a3ef681e5e9d5df558e855d86ccd4708d6200 ]
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... (cherry picked from commit f1ceb9d10043683b89e5e5e5848fb4e855295762) Signed-off-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/vc4/vc4_hdmi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index 879c1fe0565de..08b3f9c87e6ec 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -1468,6 +1468,7 @@ 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;
@@ -1493,8 +1494,9 @@ 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,