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>

diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index a73c057f63fd0c6ca0ac8511921ebd4dbabd4cab..b2dbf7c468afca28af206786b2f033716e01e0a4 100644 (file)
--- 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);