linux-kernel - [PATCH] drivers: i2c: i2c-st: Update i2c timings

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]

Date:	Fri, 16 May 2014 17:32:10 +0200
From:	Maxime COQUELIN <maxime.coquelin@...com>
To:	Wolfram Sang <wsa@...-dreams.de>, linux-i2c@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Srinivas Kandagatla <srinivas.kandagatla@...il.com>,
	Patrice Chotard <patrice.chotard@...com>
Cc:	kernel@...inux.com, maxime.coquelin@...com
Subject: [PATCH] drivers: i2c: i2c-st: Update i2c timings

The i2c timing values specified in the driver are the minimun
values defined in the I2C specifications.
The I2C specification does not specify any default or maximum values.

Some I2C devices are out of spec, and might not work properly with minimum
values.

This patch adds a 10% margin on all the timings.

Signed-off-by: Maxime Coquelin <maxime.coquelin@...com>
---
 drivers/i2c/busses/i2c-st.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/i2c/busses/i2c-st.c b/drivers/i2c/busses/i2c-st.c
index 8720161..09142f1 100644
--- a/drivers/i2c/busses/i2c-st.c
+++ b/drivers/i2c/busses/i2c-st.c
@@ -210,21 +210,21 @@ static inline void st_i2c_clr_bits(void __iomem *reg, u32 mask)
 static struct st_i2c_timings i2c_timings[] = {
 	[I2C_MODE_STANDARD] = {
 		.rate			= 100000,
-		.rep_start_hold		= 4000,
-		.rep_start_setup	= 4700,
-		.start_hold		= 4000,
-		.data_setup_time	= 250,
-		.stop_setup_time	= 4000,
-		.bus_free_time		= 4700,
+		.rep_start_hold		= 4400,
+		.rep_start_setup	= 5170,
+		.start_hold		= 4400,
+		.data_setup_time	= 275,
+		.stop_setup_time	= 4400,
+		.bus_free_time		= 5170,
 	},
 	[I2C_MODE_FAST] = {
 		.rate			= 400000,
-		.rep_start_hold		= 600,
-		.rep_start_setup	= 600,
-		.start_hold		= 600,
-		.data_setup_time	= 100,
-		.stop_setup_time	= 600,
-		.bus_free_time		= 1300,
+		.rep_start_hold		= 660,
+		.rep_start_setup	= 660,
+		.start_hold		= 660,
+		.data_setup_time	= 110,
+		.stop_setup_time	= 660,
+		.bus_free_time		= 1430,
 	},
 };
 
-- 
1.9.1

--
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/