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

From: Maxime Ripard
Date: Tue Sep 14 2021 - 05:35:40 EST


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@xxxxxxxxxx>
---
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