On Sun, Mar 27, 2011 at 04:32:43PM -0400, Amit Daniel Kachhap wrote:
> This patch adds PM runtime management support in the I2C driver.
> The functionality of the driver is not modified much but some extra I2C
> states are added for PM runtime. The runtime suspend keeps the interrupt
> for the I2C interface disabled.
ok, whilst this looks ok, it's too late for the current merge window,
so will go into the -next for the next kernel
> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-s3c2410.c | 61 +++++++++++++++++++++++++++++++++-----
> 1 files changed, 53 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
> index 6c00c10..8ebe621 100644
> --- a/drivers/i2c/busses/i2c-s3c2410.c
> +++ b/drivers/i2c/busses/i2c-s3c2410.c
> @@ -35,6 +35,7 @@
> #include <linux/cpufreq.h>
> #include <linux/slab.h>
> #include <linux/io.h>
> +#include <linux/pm_runtime.h>
>
> #include <asm/irq.h>
>
> @@ -48,7 +49,9 @@ enum s3c24xx_i2c_state {
> STATE_START,
> STATE_READ,
> STATE_WRITE,
> - STATE_STOP
> + STATE_STOP,
> + STATE_STANDBY,
> + STATE_SUSPEND
> };
>
> enum s3c24xx_i2c_type {
> @@ -59,7 +62,6 @@ enum s3c24xx_i2c_type {
> struct s3c24xx_i2c {
> spinlock_t lock;
> wait_queue_head_t wait;
> - unsigned int suspended:1;
>
> struct i2c_msg *msg;
> unsigned int msg_num;
> @@ -400,8 +402,13 @@ static int i2s_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat)
> i2c->msg++;
> }
> }
> + break;
>
> + default:
> + dev_err(i2c->dev, "%s: called with invalid state\n", __func__);
> + goto out;
> break;
> +
> }
>
> /* acknowlegde the IRQ and get back on with the work */
> @@ -485,7 +492,7 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c,
> int spins = 20;
> int ret;
>
> - if (i2c->suspended)
> + if (i2c->state == STATE_SUSPEND)
> return -EIO;
>
> ret = s3c24xx_i2c_set_master(i2c);
> @@ -555,12 +562,14 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
> int ret;
>
> clk_enable(i2c->clk);
> + pm_runtime_get_sync(i2c->dev);
>
> for (retry = 0; retry < adap->retries; retry++) {
>
> ret = s3c24xx_i2c_doxfer(i2c, msgs, num);
>
> if (ret != -EAGAIN) {
> + pm_runtime_put_sync(i2c->dev);
> clk_disable(i2c->clk);
> return ret;
> }
> @@ -570,6 +579,7 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
> udelay(100);
> }
>
> + pm_runtime_put_sync(i2c->dev);
> clk_disable(i2c->clk);
> return -EREMOTEIO;
> }
> @@ -912,10 +922,14 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
> goto err_cpufreq;
> }
>
> + /*Set Initial I2C state*/
> + i2c->state = STATE_STANDBY;
> +
> platform_set_drvdata(pdev, i2c);
>
> dev_info(&pdev->dev, "%s: S3C I2C adapter\n", dev_name(&i2c->adap.dev));
> clk_disable(i2c->clk);
> + pm_runtime_enable(&pdev->dev);
> return 0;
>
> err_cpufreq:
> @@ -956,6 +970,7 @@ static int s3c24xx_i2c_remove(struct platform_device *pdev)
>
> clk_disable(i2c->clk);
> clk_put(i2c->clk);
> + pm_runtime_disable(&pdev->dev);
>
> iounmap(i2c->regs);
>
> @@ -972,9 +987,9 @@ static int s3c24xx_i2c_suspend_noirq(struct device *dev)
> struct platform_device *pdev = to_platform_device(dev);
> struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
>
> - i2c->suspended = 1;
> -
> + i2c->state = STATE_SUSPEND;
> return 0;
> +
> }
>
> static int s3c24xx_i2c_resume(struct device *dev)
> @@ -982,17 +997,47 @@ static int s3c24xx_i2c_resume(struct device *dev)
> struct platform_device *pdev = to_platform_device(dev);
> struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
>
> - i2c->suspended = 0;
> clk_enable(i2c->clk);
> s3c24xx_i2c_init(i2c);
> + i2c->state = STATE_STANDBY;
> clk_disable(i2c->clk);
>
> return 0;
> }
>
> +static int s3c_i2c_runtime_suspend(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
> +
> + i2c->state = STATE_STANDBY;
> + s3c24xx_i2c_disable_irq(i2c);
> + s3c24xx_i2c_disable_ack(i2c);
> +
> + return 0;
> +}
> +
> +static int s3c_i2c_runtime_resume(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
> +
> + if (i2c->state != STATE_STANDBY)
> + return 0;
> +
> + /*No major activity in runtime resume because all the registers are
> + re-initialised for each i2c transfer, so just changing the state*/
> + i2c->state = STATE_IDLE;
> +
> + return 0;
> +}
> +
> +
> static const struct dev_pm_ops s3c24xx_i2c_dev_pm_ops = {
> - .suspend_noirq = s3c24xx_i2c_suspend_noirq,
> - .resume = s3c24xx_i2c_resume,
> + .suspend_noirq = s3c24xx_i2c_suspend_noirq,
> + .resume = s3c24xx_i2c_resume,
> + .runtime_suspend = s3c_i2c_runtime_suspend,
> + .runtime_resume = s3c_i2c_runtime_resume,
> };
>
> #define S3C24XX_DEV_PM_OPS (&s3c24xx_i2c_dev_pm_ops)
> --
> 1.7.1
>
>
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