From 8ef4f4e4afd55b6015d5b283172d240e22c91854 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Thu, 23 Sep 2010 09:03:55 +0200 Subject: [PATCH] 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 Signed-off-by: Sundar R Iyer Signed-off-by: Linus Walleij Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-nomadik.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c index a73c057f63f..b2dbf7c468a 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); -- 2.39.3