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Commit db3a3d4e authored by Richard Zhao's avatar Richard Zhao Committed by Ben Dooks
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i2c: imx: disable clock when it's possible to save power. 



Enable clock before START, disable it after STOP.

Signed-off-by: default avatarRichard Zhao <linuxzsc@gmail.com>
Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
parent a4094a76

drivers/i2c/busses/i2c-imx.c

+6 −6
Original line number Diff line number Diff line
@@ -121,6 +121,7 @@ struct imx_i2c_struct { 
	unsigned long		i2csr;

	unsigned int 		disable_delay;

	int			stopped;

	unsigned int		ifdr; /* IMX_I2C_IFDR */

};



/** Functions for IMX I2C adapter driver ***************************************
@@ -192,6 +193,8 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx) 


	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);



	clk_enable(i2c_imx->clk);

	writeb(i2c_imx->ifdr, i2c_imx->base + IMX_I2C_IFDR);

	/* Enable I2C controller */

	writeb(0, i2c_imx->base + IMX_I2C_I2SR);

	writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
@@ -238,6 +241,7 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx) 


	/* Disable I2C controller */

	writeb(0, i2c_imx->base + IMX_I2C_I2CR);

	clk_disable(i2c_imx->clk);

}



static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
@@ -257,8 +261,8 @@ static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx, 
	else

		for (i = 0; i2c_clk_div[i][0] < div; i++);



	/* Write divider value to register */

	writeb(i2c_clk_div[i][1], i2c_imx->base + IMX_I2C_IFDR);

	/* Store divider value */

	i2c_imx->ifdr = i2c_clk_div[i][1];



	/*

	 * There dummy delay is calculated.
@@ -528,7 +532,6 @@ static int __init i2c_imx_probe(struct platform_device *pdev) 
		dev_err(&pdev->dev, "can't get I2C clock\n");

		goto fail3;

	}

	clk_enable(i2c_imx->clk);



	/* Request IRQ */

	ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
@@ -577,7 +580,6 @@ static int __init i2c_imx_probe(struct platform_device *pdev) 
fail5:

	free_irq(i2c_imx->irq, i2c_imx);

fail4:

	clk_disable(i2c_imx->clk);

	clk_put(i2c_imx->clk);

fail3:

	release_mem_region(i2c_imx->res->start, resource_size(res));
@@ -614,8 +616,6 @@ static int __exit i2c_imx_remove(struct platform_device *pdev) 
	if (pdata && pdata->exit)

		pdata->exit(&pdev->dev);



	/* Disable I2C clock */

	clk_disable(i2c_imx->clk);

	clk_put(i2c_imx->clk);



	release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));