diff options
| author | Richard Zhao <linuxzsc@gmail.com> | 2009-10-17 17:46:24 +0800 |
|---|---|---|
| committer | Ben Dooks <ben-linux@fluff.org> | 2009-11-02 23:28:47 +0000 |
| commit | db3a3d4ef7f676501325ae9c7ce0c193c2c1b28f (patch) | |
| tree | 811858ab7f415c9e584d0704d0e8c234cd67d9c7 /drivers/i2c/busses/i2c-imx.c | |
| parent | a4094a76e6a45691b8f9108060b750a48b4c4563 (diff) | |
| download | lwn-db3a3d4ef7f676501325ae9c7ce0c193c2c1b28f.tar.gz lwn-db3a3d4ef7f676501325ae9c7ce0c193c2c1b28f.zip | |
i2c: imx: disable clock when it's possible to save power.
Enable clock before START, disable it after STOP.
Signed-off-by: Richard Zhao <linuxzsc@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Diffstat (limited to 'drivers/i2c/busses/i2c-imx.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-imx.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 671d37c23f4c..e3654d683e15 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -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)); |