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soft_i2c: Pull SDA high before reading

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Spotted by Dean Capindale.

Systems that support open-drain GPIO properly are allowed provide an
empty I2C_TRISTATE define. However, this means that we need to be
careful not to drive SDA low when the slave is expected to respond.

This patch adds a missing I2C_SDA(1) to read_byte() required to
tristate the SDA line on systems that support open-drain GPIO.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
This commit is contained in:
Haavard Skinnemoen 2008-05-16 11:08:11 +02:00 • committed by Wolfgang Denk
parent f979690ee3
commit 110e006fe6
1 changed files with 1 additions and 0 deletions
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common/soft_i2c.c
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@ -252,6 +252,7 @@ static uchar read_byte(int ack)
* Read 8 bits, MSB first.
*/
I2C_TRISTATE;
I2C_SDA(1);
data = 0;
for(j = 0; j < 8; j++) {
I2C_SCL(0);