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i2c-s3c2410: Enable i2c clock only when doing some transfert

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This patch modify the s3c2410 i2c driver behaviour to enable the
i2c clock only when needed. I'm not sure if this has a big impact
on power usage but at least it's fixing a bug with the uda1380
codec which needs to be hard reset'ed if the i2c clock is enabled
before it's powered on (at least on h1940).

Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This commit is contained in:
Arnaud Patard (Rtp) 2010-07-15 15:06:14 +02:00 committed by Ben Dooks
parent f6f94e2ab1
commit d2360b8e84
1 changed files with 9 additions and 1 deletions
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10
drivers/i2c/busses/i2c-s3c2410.c
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@ -555,18 +555,23 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
int retry;
int ret;
clk_enable(i2c->clk);
for (retry = 0; retry < adap->retries; retry++) {
ret = s3c24xx_i2c_doxfer(i2c, msgs, num);
if (ret != -EAGAIN)
if (ret != -EAGAIN) {
clk_disable(i2c->clk);
return ret;
}
dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry);
udelay(100);
}
clk_disable(i2c->clk);
return -EREMOTEIO;
}
@ -911,6 +916,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, i2c);
dev_info(&pdev->dev, "%s: S3C I2C adapter\n", dev_name(&i2c->adap.dev));
clk_disable(i2c->clk);
return 0;
err_cpufreq:
@ -978,7 +984,9 @@ static int s3c24xx_i2c_resume(struct device *dev)
struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
i2c->suspended = 0;
clk_enable(i2c->clk);
s3c24xx_i2c_init(i2c);
clk_disable(i2c->clk);
return 0;
}