linux-kernel - [PATCH v2 2/3] drm/vc4: hdmi: Convert to the new clock request API

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Message-Id: <20210914093515.260031-3-maxime@cerno.tech>
Date:   Tue, 14 Sep 2021 11:35:14 +0200
From:   Maxime Ripard <maxime@...no.tech>
To:     Mike Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        dri-devel@...ts.freedesktop.org,
        Daniel Vetter <daniel.vetter@...el.com>,
        David Airlie <airlied@...ux.ie>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        Maxime Ripard <maxime@...no.tech>
Cc:     Maxime Ripard <mripard@...nel.org>, linux-clk@...r.kernel.org,
        Dave Stevenson <dave.stevenson@...pberrypi.com>,
        Phil Elwell <phil@...pberrypi.com>,
        Tim Gover <tim.gover@...pberrypi.com>,
        Dom Cobley <dom@...pberrypi.com>,
        Emma Anholt <emma@...olt.net>, linux-kernel@...r.kernel.org,
        Russell King <linux@...linux.org.uk>
Subject: [PATCH v2 2/3] drm/vc4: hdmi: Convert to the new clock request API

The new clock request API allows us to increase the rate of the HSM
clock to match our pixel rate requirements while decreasing it when
we're done, resulting in a better power-efficiency.

Signed-off-by: Maxime Ripard <maxime@...no.tech>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 15 ++++++++++-----
 drivers/gpu/drm/vc4/vc4_hdmi.h |  3 +++
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 4a1115043114..099a94570e86 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -635,6 +635,8 @@ static void vc4_hdmi_encoder_post_crtc_powerdown(struct drm_encoder *encoder,
 		vc4_hdmi->variant->phy_disable(vc4_hdmi);
 
 	clk_disable_unprepare(vc4_hdmi->pixel_bvb_clock);
+	clk_request_done(vc4_hdmi->bvb_req);
+	clk_request_done(vc4_hdmi->hsm_req);
 	clk_disable_unprepare(vc4_hdmi->pixel_clock);
 
 	ret = pm_runtime_put(&vc4_hdmi->pdev->dev);
@@ -941,9 +943,9 @@ static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
 	 * pixel clock, but HSM ends up being the limiting factor.
 	 */
 	hsm_rate = max_t(unsigned long, 120000000, (pixel_rate / 100) * 101);
-	ret = clk_set_min_rate(vc4_hdmi->hsm_clock, hsm_rate);
-	if (ret) {
-		DRM_ERROR("Failed to set HSM clock rate: %d\n", ret);
+	vc4_hdmi->hsm_req = clk_request_start(vc4_hdmi->hsm_clock, hsm_rate);
+	if (IS_ERR(vc4_hdmi->hsm_req)) {
+		DRM_ERROR("Failed to set HSM clock rate: %ld\n", PTR_ERR(vc4_hdmi->hsm_req));
 		return;
 	}
 
@@ -956,9 +958,10 @@ static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
 	else
 		bvb_rate = 75000000;
 
-	ret = clk_set_min_rate(vc4_hdmi->pixel_bvb_clock, bvb_rate);
+	vc4_hdmi->bvb_req = clk_request_start(vc4_hdmi->pixel_bvb_clock, bvb_rate);
 	if (ret) {
-		DRM_ERROR("Failed to set pixel bvb clock rate: %d\n", ret);
+		DRM_ERROR("Failed to set pixel bvb clock rate: %ld\n", PTR_ERR(vc4_hdmi->bvb_req));
+		clk_request_done(vc4_hdmi->hsm_req);
 		clk_disable_unprepare(vc4_hdmi->pixel_clock);
 		return;
 	}
@@ -966,6 +969,8 @@ static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
 	ret = clk_prepare_enable(vc4_hdmi->pixel_bvb_clock);
 	if (ret) {
 		DRM_ERROR("Failed to turn on pixel bvb clock: %d\n", ret);
+		clk_request_done(vc4_hdmi->bvb_req);
+		clk_request_done(vc4_hdmi->hsm_req);
 		clk_disable_unprepare(vc4_hdmi->pixel_clock);
 		return;
 	}
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h
index 33e9f665ab8e..683b2d8a3dca 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.h
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
@@ -176,6 +176,9 @@ struct vc4_hdmi {
 
 	struct reset_control *reset;
 
+	struct clk_request *bvb_req;
+	struct clk_request *hsm_req;
+
 	struct debugfs_regset32 hdmi_regset;
 	struct debugfs_regset32 hd_regset;
 };
-- 
2.31.1