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authorLinus Walleij <linus.walleij@stericsson.com>2010-09-23 09:03:55 +0200
committerBen Dooks <ben-linux@fluff.org>2010-10-25 02:40:38 +0100
commit8ef4f4e4afd55b6015d5b283172d240e22c91854 (patch)
tree5769f2ba31054d8053080f52822233103595533b /drivers/i2c
parent1804edd15c66a7af11f9e6194b4c783b37c5fe98 (diff)
i2c-nomadik: dynamic clocking
This makes sure the Nomadik I2C bus driver silicon is only clocked when really needed, saving some microamps here and there when there is no I2C traffic. Acked-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com> Signed-off-by: Sundar R Iyer <sundar.iyer@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-nomadik.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index a73c057f63fd..b2dbf7c468af 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -250,6 +250,8 @@ static int init_hw(struct nmk_i2c_dev *dev)
{
int stat;
+ clk_enable(dev->clk);
+
stat = flush_i2c_fifo(dev);
if (stat)
return stat;
@@ -263,6 +265,8 @@ static int init_hw(struct nmk_i2c_dev *dev)
dev->cli.operation = I2C_NO_OPERATION;
+ clk_disable(dev->clk);
+
return 0;
}
@@ -558,6 +562,8 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
if (status)
return status;
+ clk_enable(dev->clk);
+
/* setup the i2c controller */
setup_i2c_controller(dev);
@@ -590,10 +596,13 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
dev_err(&dev->pdev->dev, "%s\n",
cause >= ARRAY_SIZE(abort_causes)
? "unknown reason" : abort_causes[cause]);
+ clk_disable(dev->clk);
return status;
}
mdelay(1);
}
+ clk_disable(dev->clk);
+
/* return the no. messages processed */
if (status)
return status;
@@ -857,8 +866,6 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)
goto err_no_clk;
}
- clk_enable(dev->clk);
-
adap = &dev->adap;
adap->dev.parent = &pdev->dev;
adap->owner = THIS_MODULE;
@@ -895,7 +902,6 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)
return 0;
err_init_hw:
- clk_disable(dev->clk);
err_add_adap:
clk_put(dev->clk);
err_no_clk:
@@ -928,7 +934,6 @@ static int __devexit nmk_i2c_remove(struct platform_device *pdev)
iounmap(dev->virtbase);
if (res)
release_mem_region(res->start, resource_size(res));
- clk_disable(dev->clk);
clk_put(dev->clk);
platform_set_drvdata(pdev, NULL);
kfree(dev);