linux-kernel - [PATCH 02/10] backlight: qcom-wled: Use cpu_to

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20211004192741.621870-3-marijn.suijten@somainline.org>
Date:   Mon,  4 Oct 2021 21:27:33 +0200
From:   Marijn Suijten <marijn.suijten@...ainline.org>
To:     phone-devel@...r.kernel.org, Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Lee Jones <lee.jones@...aro.org>,
        Daniel Thompson <daniel.thompson@...aro.org>,
        Jingoo Han <jingoohan1@...il.com>
Cc:     ~postmarketos/upstreaming@...ts.sr.ht,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...ainline.org>,
        Konrad Dybcio <konrad.dybcio@...ainline.org>,
        Martin Botka <martin.botka@...ainline.org>,
        Jami Kettunen <jami.kettunen@...ainline.org>,
        Pavel Dubrova <pashadubrova@...il.com>,
        Marijn Suijten <marijn.suijten@...ainline.org>,
        Kiran Gunda <kgunda@...eaurora.org>,
        Courtney Cavin <courtney.cavin@...ymobile.com>,
        Bryan Wu <cooloney@...il.com>, linux-arm-msm@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, linux-fbdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 02/10] backlight: qcom-wled: Use cpu_to_le16 macro to perform conversion

The kernel already provides appropriate primitives to perform endianness
conversion which should be used in favour of manual bit-wrangling.

Signed-off-by: Marijn Suijten <marijn.suijten@...ainline.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@...ainline.org>
---
 drivers/video/backlight/qcom-wled.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index 6af808af2328..9927ed98944a 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -231,14 +231,14 @@ struct wled {
 static int wled3_set_brightness(struct wled *wled, u16 brightness)
 {
 	int rc, i;
-	u8 v[2];
+	u16 v;
 
-	v[0] = brightness & 0xff;
-	v[1] = (brightness >> 8) & 0xf;
+	v = cpu_to_le16(brightness & WLED3_SINK_REG_BRIGHT_MAX);
 
 	for (i = 0;  i < wled->cfg.num_strings; ++i) {
 		rc = regmap_bulk_write(wled->regmap, wled->ctrl_addr +
-				       WLED3_SINK_REG_BRIGHT(i), v, 2);
+				       WLED3_SINK_REG_BRIGHT(i),
+				       &v, sizeof(v));
 		if (rc < 0)
 			return rc;
 	}
@@ -249,19 +249,18 @@ static int wled3_set_brightness(struct wled *wled, u16 brightness)
 static int wled4_set_brightness(struct wled *wled, u16 brightness)
 {
 	int rc, i;
-	u16 low_limit = wled->max_brightness * 4 / 1000;
-	u8 v[2];
+	u16 v, low_limit = wled->max_brightness * 4 / 1000;
 
 	/* WLED4's lower limit of operation is 0.4% */
 	if (brightness > 0 && brightness < low_limit)
 		brightness = low_limit;
 
-	v[0] = brightness & 0xff;
-	v[1] = (brightness >> 8) & 0xf;
+	v = cpu_to_le16(brightness & WLED3_SINK_REG_BRIGHT_MAX);
 
 	for (i = 0;  i < wled->cfg.num_strings; ++i) {
 		rc = regmap_bulk_write(wled->regmap, wled->sink_addr +
-				       WLED4_SINK_REG_BRIGHT(i), v, 2);
+				       WLED4_SINK_REG_BRIGHT(i),
+				       &v, sizeof(v));
 		if (rc < 0)
 			return rc;
 	}
@@ -272,22 +271,20 @@ static int wled4_set_brightness(struct wled *wled, u16 brightness)
 static int wled5_set_brightness(struct wled *wled, u16 brightness)
 {
 	int rc, offset;
-	u16 low_limit = wled->max_brightness * 1 / 1000;
-	u8 v[2];
+	u16 v, low_limit = wled->max_brightness * 1 / 1000;
 
 	/* WLED5's lower limit is 0.1% */
 	if (brightness < low_limit)
 		brightness = low_limit;
 
-	v[0] = brightness & 0xff;
-	v[1] = (brightness >> 8) & 0x7f;
+	v = cpu_to_le16(brightness & WLED5_SINK_REG_BRIGHT_MAX_15B);
 
 	offset = (wled->cfg.mod_sel == MOD_A) ?
 		  WLED5_SINK_REG_MOD_A_BRIGHTNESS_LSB :
 		  WLED5_SINK_REG_MOD_B_BRIGHTNESS_LSB;
 
 	rc = regmap_bulk_write(wled->regmap, wled->sink_addr + offset,
-			       v, 2);
+			       &v, sizeof(v));
 	return rc;
 }
 
-- 
2.33.0