linux-kernel - [PATCH] gpio: twl4030: Correct status reporting when the GPIO is used as output

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: <1354700985-4453-1-git-send-email-peter.ujfalusi@ti.com>
Date:	Wed, 5 Dec 2012 10:49:45 +0100
From:	Peter Ujfalusi <peter.ujfalusi@...com>
To:	Grant Likely <grant.likely@...retlab.ca>,
	Linus Walleij <linus.walleij@...aro.org>
CC:	<linux-kernel@...r.kernel.org>, <linux-omap@...r.kernel.org>
Subject: [PATCH] gpio: twl4030: Correct status reporting when the GPIO is used as output

When the GPIO is configured as output we need to read the GPIODATAOUT*
register to get correct information. When the GPIO is output the GPIODATAIN*
registers report 0 all the time (no feedback from output path).

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@...com>
---
 drivers/gpio/gpio-twl4030.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-twl4030.c b/drivers/gpio/gpio-twl4030.c
index 55b4fe4..e7aa620 100644
--- a/drivers/gpio/gpio-twl4030.c
+++ b/drivers/gpio/gpio-twl4030.c
@@ -191,13 +191,19 @@ static int twl4030_get_gpio_datain(int gpio)
 	u8 d_bnk = gpio >> 3;
 	u8 d_off = gpio & 0x7;
 	u8 base = 0;
+	int direction;
 	int ret = 0;
 
 	if (unlikely((gpio >= TWL4030_GPIO_MAX)
 		|| !(gpio_usage_count & BIT(gpio))))
 		return -EPERM;
 
-	base = REG_GPIODATAIN1 + d_bnk;
+	direction = gpio_twl4030_read(REG_GPIODATADIR1 + d_bnk);
+	if (direction > 0 && (direction >> d_off) & 0x1)
+		base = REG_SETGPIODATAOUT1 + d_bnk;
+	else
+		base = REG_GPIODATAIN1 + d_bnk;
+
 	ret = gpio_twl4030_read(base);
 	if (ret > 0)
 		ret = (ret >> d_off) & 0x1;
-- 
1.8.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/