linux-kernel - [PATCH v2 1/1] phy: tusb1210: use bitmasks to set VENDOR

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-next>] [day] [month] [year] [list]

Message-Id: <20200714163243.6452-1-liambeguin@gmail.com>
Date:   Tue, 14 Jul 2020 12:32:43 -0400
From:   Liam Beguin <liambeguin@...il.com>
To:     liambeguin@...il.com, kishon@...com, vkoul@...nel.org
Cc:     linux-kernel@...r.kernel.org
Subject: [PATCH v2 1/1] phy: tusb1210: use bitmasks to set VENDOR_SPECIFIC2

From: Liam Beguin <lvb@...hos.com>

Start by reading the content of the VENDOR_SPECIFIC2 register and update
each bit field based on device properties when defined.

The use of bit masks prevents fields from overriding each other and
enables users to clear bits which are set by default, like datapolarity
in this instance.

Signed-off-by: Liam Beguin <lvb@...hos.com>
---
 drivers/phy/ti/phy-tusb1210.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/phy/ti/phy-tusb1210.c b/drivers/phy/ti/phy-tusb1210.c
index d8d0cc11d187..35baeb9deeee 100644
--- a/drivers/phy/ti/phy-tusb1210.c
+++ b/drivers/phy/ti/phy-tusb1210.c
@@ -13,9 +13,9 @@
 #include <linux/phy/ulpi_phy.h>
 
 #define TUSB1210_VENDOR_SPECIFIC2		0x80
-#define TUSB1210_VENDOR_SPECIFIC2_IHSTX_SHIFT	0
-#define TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_SHIFT	4
-#define TUSB1210_VENDOR_SPECIFIC2_DP_SHIFT	6
+#define TUSB1210_VENDOR_SPECIFIC2_IHSTX_MASK	GENMASK(3, 0)
+#define TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_MASK	GENMASK(5, 4)
+#define TUSB1210_VENDOR_SPECIFIC2_DP_MASK	BIT(6)
 
 struct tusb1210 {
 	struct ulpi *ulpi;
@@ -118,22 +118,22 @@ static int tusb1210_probe(struct ulpi *ulpi)
 	 * diagram optimization and DP/DM swap.
 	 */
 
+	reg = ulpi_read(ulpi, TUSB1210_VENDOR_SPECIFIC2);
+
 	/* High speed output drive strength configuration */
-	device_property_read_u8(&ulpi->dev, "ihstx", &val);
-	reg = val << TUSB1210_VENDOR_SPECIFIC2_IHSTX_SHIFT;
+	if (!device_property_read_u8(&ulpi->dev, "ihstx", &val))
+		reg = set_mask_bits(&reg, TUSB1210_VENDOR_SPECIFIC2_IHSTX_MASK, val);
 
 	/* High speed output impedance configuration */
-	device_property_read_u8(&ulpi->dev, "zhsdrv", &val);
-	reg |= val << TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_SHIFT;
+	if (!device_property_read_u8(&ulpi->dev, "zhsdrv", &val))
+		reg = set_mask_bits(&reg, TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_MASK, val);
 
 	/* DP/DM swap control */
-	device_property_read_u8(&ulpi->dev, "datapolarity", &val);
-	reg |= val << TUSB1210_VENDOR_SPECIFIC2_DP_SHIFT;
+	if (!device_property_read_u8(&ulpi->dev, "datapolarity", &val))
+		reg = set_mask_bits(&reg, TUSB1210_VENDOR_SPECIFIC2_DP_MASK, val);
 
-	if (reg) {
-		ulpi_write(ulpi, TUSB1210_VENDOR_SPECIFIC2, reg);
-		tusb->vendor_specific2 = reg;
-	}
+	ulpi_write(ulpi, TUSB1210_VENDOR_SPECIFIC2, reg);
+	tusb->vendor_specific2 = reg;
 
 	tusb->phy = ulpi_phy_create(ulpi, &phy_ops);
 	if (IS_ERR(tusb->phy))

base-commit: 8f3d9f354286745c751374f5f1fcafee6b3f3136
-- 
2.27.0