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From:   Maxime Ripard <maxime@cerno.tech>
To:     Eric Anholt <eric@anholt.net>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Maxime Ripard <maxime@cerno.tech>,
        Daniel Vetter <daniel.vetter@intel.com>,
        David Airlie <airlied@linux.ie>
Cc:     linux-rpi-kernel@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        bcm-kernel-feedback-list@broadcom.com,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Dave Stevenson <dave.stevenson@raspberrypi.com>,
        linux-media@vger.kernel.org
Subject: [PATCH v2 08/15] drm/vc4: hdmi: Introduce a CEC clock
Date:   Mon, 11 Jan 2021 15:23:02 +0100
Message-Id: <20210111142309.193441-9-maxime@cerno.tech>
In-Reply-To: <20210111142309.193441-1-maxime@cerno.tech>
References: <20210111142309.193441-1-maxime@cerno.tech>
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Precedence: bulk

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