drm/vc4: hdmi: Introduce a CEC clock

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>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Tested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://patchwork.freedesktop.org/patch/msgid/20210111142309.193441-9-maxime@cerno.tech
(cherry picked from commit cd7f016c93b697dea79a884162cbf7311283fe12)
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index d5a2e93..56209cb 100644 (file)
--- 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);
 }
@@ -1753,6 +1753,7 @@ 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;
 }
@@ -1846,6 +1847,12 @@ 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 4c8994c..6966db1 100644 (file)
--- 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;