On Mon, Oct 20, 2014 at 11:42:14AM +0800, Wenyou Yang wrote:
> Amend the i2c at91 pin controller to optionally take a pin control
> handle and set the state of the pins to:
>
> - "default" on boot, resume and before performing an transfer
> - "sleep" on suspend()
>
> This should make it possible to optimize energy usage for the pins
> both for the suspend/resume cycle
>
> Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx>
Acked by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-at91.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
> index 8f408f8..ed2c382 100644
> --- a/drivers/i2c/busses/i2c-at91.c
> +++ b/drivers/i2c/busses/i2c-at91.c
> @@ -32,6 +32,7 @@
> #include <linux/slab.h>
> #include <linux/platform_data/dma-atmel.h>
> #include <linux/pm_runtime.h>
> +#include <linux/pinctrl/consumer.h>
>
> #define DEFAULT_TWI_CLK_HZ 100000 /* max 400 Kbits/s */
> #define AT91_I2C_TIMEOUT msecs_to_jiffies(100) /* transfer timeout */
> @@ -748,6 +749,8 @@ static int at91_twi_probe(struct platform_device *pdev)
> u32 phy_addr;
> u32 bus_clk_rate;
>
> + pinctrl_pm_select_default_state(&pdev->dev);
> +
> dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
> if (!dev)
> return -ENOMEM;
> @@ -850,8 +853,10 @@ static int at91_twi_suspend(struct device *dev)
> {
> struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
>
> - if (!pm_runtime_suspended(dev))
> + if (!pm_runtime_suspended(dev)) {
> clk_disable_unprepare(twi_dev->clk);
> + pinctrl_pm_select_sleep_state(dev);
> + }
>
> return 0;
> }
> @@ -862,6 +867,7 @@ static int at91_twi_resume(struct device *dev)
> int ret;
>
> if (!pm_runtime_suspended(dev)) {
> + pinctrl_pm_select_default_state(dev);
> ret = clk_prepare_enable(twi_dev->clk);
> if (ret)
> return ret;
> @@ -881,6 +887,8 @@ static int at91_twi_runtime_suspend(struct device *dev)
>
> clk_disable_unprepare(twi_dev->clk);
>
> + pinctrl_pm_select_sleep_state(dev);
> +
> return 0;
> }
>
> @@ -888,6 +896,8 @@ static int at91_twi_runtime_resume(struct device *dev)
> {
> struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
>
> + pinctrl_pm_select_default_state(dev);
> +
> return clk_prepare_enable(twi_dev->clk);
> }
> #endif
> --
> 1.7.9.5
>
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