[PATCH v2 08/15] drm/vc4: hdmi: Introduce a CEC clock

Maxime Ripard
2021-01-11T14:26:10Z

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.

Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
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 0627b8db32f6..7b5c92df8f1b 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);
}
@@ -1752,6 +1752,7 @@ 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;
}
@@ -1845,6 +1846,12 @@ 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);
+ }
+
vc4_hdmi->reset = devm_reset_control_get(dev, NULL);
if (IS_ERR(vc4_hdmi->reset)) {
DRM_ERROR("Failed to get HDMI reset line\n");
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h
index 4c8994cfd932..6966db1a0957 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.h
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
@@ -155,6 +155,7 @@ struct vc4_hdmi {
bool cec_tx_ok;
bool cec_irq_was_rx;

+ struct clk *cec_clock;
struct clk *pixel_clock;
struct clk *hsm_clock;
struct clk *audio_clock;
--
2.29.2