Hi Dave,
On Fri, Dec 18, 2020 at 11:37:50AM +0000, Dave Stevenson wrote:
Hi Maxime
On Thu, 10 Dec 2020 at 13:47, Maxime Ripard maxime@cerno.tech wrote:
While the BCM2835 had the CEC clock derived from the HSM clock, the BCM2711 has a dedicated parent clock for it.
Let's introduce a separate clock for it so that we can handle both cases.
Signed-off-by: Maxime Ripard maxime@cerno.tech
drivers/gpu/drm/vc4/vc4_hdmi.c | 9 ++++++++- drivers/gpu/drm/vc4/vc4_hdmi.h | 1 + 2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index b93ee3e26e2b..0debd22bc992 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -145,7 +145,7 @@ static void vc4_hdmi_cec_update_clk_div(struct vc4_hdmi *vc4_hdmi) * 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;
clk_cnt = clk_get_rate(vc4_hdmi->cec_clock) / CEC_CLOCK_FREQ; value |= clk_cnt << VC4_HDMI_CEC_DIV_CLK_CNT_SHIFT; HDMI_WRITE(HDMI_CEC_CNTRL_1, value);} @@ -1740,6 +1740,7 @@ static int vc4_hdmi_init_resources(struct vc4_hdmi *vc4_hdmi) return PTR_ERR(vc4_hdmi->hsm_clock); } vc4_hdmi->audio_clock = vc4_hdmi->hsm_clock;
vc4_hdmi->cec_clock = vc4_hdmi->hsm_clock; return 0;} @@ -1833,6 +1834,12 @@ static int vc5_hdmi_init_resources(struct vc4_hdmi *vc4_hdmi) return PTR_ERR(vc4_hdmi->audio_clock); }
vc4_hdmi->cec_clock = devm_clk_get(dev, "cec");if (IS_ERR(vc4_hdmi->cec_clock)) {DRM_ERROR("Failed to get CEC clock\n");return PTR_ERR(vc4_hdmi->cec_clock);}Aren't we adding to the DT binding here and breaking backwards compatibility? Admittedly CEC didn't work before (and was masked out) for vc5, but do we need to worry about those with existing DT files that currently work happily?
The DT compatibility is not a worry here: I made sure the CEC clock and range were part of the binding since it's been introduced:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
So we were not using it so far, but it was in the DT all along
Maxime