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SubjectRE: [PATCH 4/6] video: s3c-fb: Take a runtime PM reference when unblanked
Date
> -----Original Message-----
> From: Mark Brown [mailto:broonie@opensource.wolfsonmicro.com]
> Sent: Tuesday, December 27, 2011 11:16 PM
> To: Jingoo Han; Florian Tobias Schandinat
> Cc: linux-fbdev@vger.kernel.org; linux-kernel@vger.kernel.org; Mark Brown
> Subject: [PATCH 4/6] video: s3c-fb: Take a runtime PM reference when unblanked
>
> When the framebuffer is unblanked hold a runtime PM reference. This
> prevents us powering down when userspace has left an image on the
> framebuffer and prepares the way for being able to power down the hardware
> when an application still has the device open.
>
> Since we now hold a runtime PM reference whenever the display is unblanked
> there is no need for the runtime power management to disable and enable
> the display, and doing so would lead to runtime PM trying to recurse into
> itself when called from the blanking code, so split the runtime PM into
> separate functions which only deal with the clocks. The PM core will
> runtime resume the device prior to system suspend.
>
> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

Acked-by: Jingoo Han <jg1.han@samsung.com>

> ---
> drivers/video/s3c-fb.c | 66 +++++++++++++++++++++++++++++++++++++++--------
> 1 files changed, 54 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/video/s3c-fb.c b/drivers/video/s3c-fb.c
> index 2e0eef0..688b9d8 100644
> --- a/drivers/video/s3c-fb.c
> +++ b/drivers/video/s3c-fb.c
> @@ -192,6 +192,7 @@ struct s3c_fb_vsync {
> * @regs: The mapped hardware registers.
> * @variant: Variant information for this hardware.
> * @enabled: A bitmask of enabled hardware windows.
> + * @output_on: Flag if the physical output is enabled.
> * @pdata: The platform configuration data passed with the device.
> * @windows: The hardware windows that have been claimed.
> * @irq_no: IRQ line number
> @@ -208,6 +209,7 @@ struct s3c_fb {
> struct s3c_fb_variant variant;
>
> unsigned char enabled;
> + bool output_on;
>
> struct s3c_fb_platdata *pdata;
> struct s3c_fb_win *windows[S3C_FB_MAX_WIN];
> @@ -449,21 +451,28 @@ static void s3c_fb_enable(struct s3c_fb *sfb, int enable)
> {
> u32 vidcon0 = readl(sfb->regs + VIDCON0);
>
> - if (enable)
> + if (enable && !sfb->output_on)
> + pm_runtime_get_sync(sfb->dev);
> +
> + if (enable) {
> vidcon0 |= VIDCON0_ENVID | VIDCON0_ENVID_F;
> - else {
> + } else {
> /* see the note in the framebuffer datasheet about
> * why you cannot take both of these bits down at the
> * same time. */
>
> - if (!(vidcon0 & VIDCON0_ENVID))
> - return;
> -
> - vidcon0 |= VIDCON0_ENVID;
> - vidcon0 &= ~VIDCON0_ENVID_F;
> + if (vidcon0 & VIDCON0_ENVID) {
> + vidcon0 |= VIDCON0_ENVID;
> + vidcon0 &= ~VIDCON0_ENVID_F;
> + }
> }
>
> writel(vidcon0, sfb->regs + VIDCON0);
> +
> + if (!enable && sfb->output_on)
> + pm_runtime_put_sync(sfb->dev);
> +
> + sfb->output_on = enable;
> }
>
> /**
> @@ -1539,7 +1548,7 @@ static int __devexit s3c_fb_remove(struct platform_device *pdev)
> return 0;
> }
>
> -#ifdef CONFIG_PM
> +#ifdef CONFIG_PM_SLEEP
> static int s3c_fb_suspend(struct device *dev)
> {
> struct platform_device *pdev = to_platform_device(dev);
> @@ -1609,11 +1618,40 @@ static int s3c_fb_resume(struct device *dev)
>
> return 0;
> }
> -#else
> -#define s3c_fb_suspend NULL
> -#define s3c_fb_resume NULL
> #endif
>
> +#ifdef CONFIG_PM_RUNTIME
> +static int s3c_fb_runtime_suspend(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct s3c_fb *sfb = platform_get_drvdata(pdev);
> +
> + if (!sfb->variant.has_clksel)
> + clk_disable(sfb->lcd_clk);
> +
> + clk_disable(sfb->bus_clk);
> +
> + return 0;
> +}
> +
> +static int s3c_fb_runtime_resume(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct s3c_fb *sfb = platform_get_drvdata(pdev);
> + struct s3c_fb_platdata *pd = sfb->pdata;
> +
> + clk_enable(sfb->bus_clk);
> +
> + if (!sfb->variant.has_clksel)
> + clk_enable(sfb->lcd_clk);
> +
> + /* setup gpio and output polarity controls */
> + pd->setup_gpio();
> + writel(pd->vidcon1, sfb->regs + VIDCON1);
> +
> + return 0;
> +}
> +#endif
>
> #define VALID_BPP124 (VALID_BPP(1) | VALID_BPP(2) | VALID_BPP(4))
> #define VALID_BPP1248 (VALID_BPP124 | VALID_BPP(8))
> @@ -1936,7 +1974,11 @@ static struct platform_device_id s3c_fb_driver_ids[] = {
> };
> MODULE_DEVICE_TABLE(platform, s3c_fb_driver_ids);
>
> -static UNIVERSAL_DEV_PM_OPS(s3cfb_pm_ops, s3c_fb_suspend, s3c_fb_resume, NULL);
> +static const struct dev_pm_ops s3cfb_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(s3c_fb_suspend, s3c_fb_resume)
> + SET_RUNTIME_PM_OPS(s3c_fb_runtime_suspend, s3c_fb_runtime_resume,
> + NULL)
> +};
>
> static struct platform_driver s3c_fb_driver = {
> .probe = s3c_fb_probe,
> --
> 1.7.7.3



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