From d2360b8e845ce0e142e72697a504ee9372421dc3 Mon Sep 17 00:00:00 2001 From: "Arnaud Patard (Rtp)" Date: Thu, 15 Jul 2010 15:06:14 +0200 Subject: [PATCH] i2c-s3c2410: Enable i2c clock only when doing some transfert 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 Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-s3c2410.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index bf831bf81587..3dc1eb9f8088 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -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; }