linux-kernel - [PATCH 1/3] drm/bridge: ti-sn65dsi86: Simplify refclk handling

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Message-Id: <20210304155144.1.Ic9c04f960190faad5290738b2a35d73661862735@changeid>
Date:   Thu,  4 Mar 2021 15:51:59 -0800
From:   Douglas Anderson <dianders@...omium.org>
To:     Andrzej Hajda <a.hajda@...sung.com>,
        Neil Armstrong <narmstrong@...libre.com>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        Jonas Karlman <jonas@...boo.se>,
        Jernej Skrabec <jernej.skrabec@...l.net>,
        Sam Ravnborg <sam@...nborg.org>
Cc:     Stephen Boyd <swboyd@...omium.org>, linux-arm-msm@...r.kernel.org,
        robdclark@...omium.org, Douglas Anderson <dianders@...omium.org>,
        Daniel Vetter <daniel@...ll.ch>,
        David Airlie <airlied@...ux.ie>,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: [PATCH 1/3] drm/bridge: ti-sn65dsi86: Simplify refclk handling

The clock framework makes it simple to deal with an optional clock.
You can call clk_get_optional() and if the clock isn't specified it'll
just return NULL without complaint. It's valid to pass NULL to
enable/disable/prepare/unprepare. Let's make use of this to simplify
things a tiny bit.

NOTE: this makes things look a tad bit asymmetric now since we check
for NULL before clk_prepare_enable() but not for
clk_disable_unprepare(). This seemed OK to me. We already have to
check for NULL in the enable case anyway so why not avoid the extra
call?

Signed-off-by: Douglas Anderson <dianders@...omium.org>
---

 drivers/gpu/drm/bridge/ti-sn65dsi86.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
index f27306c51e4d..942019842ff4 100644
--- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
@@ -1261,14 +1261,9 @@ static int ti_sn_bridge_probe(struct i2c_client *client,
 		return ret;
 	}
 
-	pdata->refclk = devm_clk_get(pdata->dev, "refclk");
-	if (IS_ERR(pdata->refclk)) {
-		ret = PTR_ERR(pdata->refclk);
-		if (ret == -EPROBE_DEFER)
-			return ret;
-		DRM_DEBUG_KMS("refclk not found\n");
-		pdata->refclk = NULL;
-	}
+	pdata->refclk = devm_clk_get_optional(pdata->dev, "refclk");
+	if (IS_ERR(pdata->refclk))
+		return PTR_ERR(pdata->refclk);
 
 	ret = ti_sn_bridge_parse_dsi_host(pdata);
 	if (ret)
-- 
2.30.1.766.gb4fecdf3b7-goog