From: Kevin Wells <wellsk40@xxxxxxxxx>
Enable I2C peripheral clocking at the start of a transfer and
disable on transfer completion to reduce peripheral power use
when bus is not in use.
Signed-off-by: Kevin Wells <wellsk40@xxxxxxxxx>
---
drivers/i2c/busses/i2c-pnx.c | 33 +++++++--------------------------
1 files changed, 7 insertions(+), 26 deletions(-)
diff --git a/drivers/i2c/busses/i2c-pnx.c b/drivers/i2c/busses/i2c-pnx.c
index 6bb6ff7..23bd556 100644
--- a/drivers/i2c/busses/i2c-pnx.c
+++ b/drivers/i2c/busses/i2c-pnx.c
@@ -448,6 +448,8 @@ i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
"%s(): entering: %d messages, stat = %04x.\n",
__func__, num, ioread32(I2C_REG_STS(alg_data)));
+ clk_enable(alg_data->clk);
+
bus_reset_if_active(alg_data);
/* Process transactions in a loop. */
@@ -516,6 +518,8 @@ i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
bus_reset_if_active(alg_data);
+ clk_disable(alg_data->clk);
+
/* Cleanup to be sure... */
alg_data->mif.buf = NULL;
alg_data->mif.len = 0;
@@ -539,29 +543,6 @@ static struct i2c_algorithm pnx_algorithm = {
.functionality = i2c_pnx_func,
};
-#ifdef CONFIG_PM
-static int i2c_pnx_controller_suspend(struct platform_device *pdev,
- pm_message_t state)
-{
- struct i2c_pnx_algo_data *alg_data = platform_get_drvdata(pdev);
-
- /* FIXME: shouldn't this be clk_disable? */
- clk_enable(alg_data->clk);
-
- return 0;
-}
-
-static int i2c_pnx_controller_resume(struct platform_device *pdev)
-{
- struct i2c_pnx_algo_data *alg_data = platform_get_drvdata(pdev);
-
- return clk_enable(alg_data->clk);
-}
-#else
-#define i2c_pnx_controller_suspend NULL
-#define i2c_pnx_controller_resume NULL
-#endif
-
static int __devinit i2c_pnx_probe(struct platform_device *pdev)
{
unsigned long tmp;
@@ -665,6 +646,9 @@ static int __devinit i2c_pnx_probe(struct platform_device *pdev)
dev_dbg(&pdev->dev, "%s: Master at %#8x, irq %d.\n",
alg_data->adapter.name, i2c_pnx->base, i2c_pnx->irq);
+ /* Disable clock until needed */
+ clk_disable(alg_data->clk);
+
return 0;
out_irq:
@@ -692,7 +676,6 @@ static int __devexit i2c_pnx_remove(struct platform_device *pdev)
free_irq(i2c_pnx->irq, alg_data);
i2c_del_adapter(&alg_data->adapter);
- clk_disable(alg_data->clk);
iounmap(alg_data->ioaddr);
release_mem_region(i2c_pnx->base, I2C_PNX_REGION_SIZE);
clk_put(alg_data->clk);
@@ -709,8 +692,6 @@ static struct platform_driver i2c_pnx_driver = {
},
.probe = i2c_pnx_probe,
.remove = __devexit_p(i2c_pnx_remove),
- .suspend = i2c_pnx_controller_suspend,
- .resume = i2c_pnx_controller_resume,
};
static int __init i2c_adap_pnx_init(void)
--
1.6.6
--
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