Hi Mark,
good to see someone adding a proper power domain support for s3c64xx.
On 12/01/2011 07:48 PM, Mark Brown wrote:
> The S3C64xx SoCs contain a set of gateable power domains which can be
> enabled and disabled at runtime in order to save power. Use the generic
> power domain code to implement support for these in software, enabling
> runtime control of most domains:
>
> - ETM (not supported in mainline).
> - Domain G: 3D acceleration (no mainline support).
> - Domain V: MFC (no mainline support).
> - Domain I: JPEG and camera interface (no mainline support).
> - Domain P: 2D acceleration, TV encoder and scaler (no mainline support)
> - Domain S: Security (no mainline support).
> - Domain F: LCD (driver already uses runtime PM), post processing and
> rotation (no mainline support).
>
> The IROM domain is marked as always enabled as we should arrange for it
> to be enabled when we suspend which will need a bit more work.
>
> Due to all the conditional device registration that the platform does
> wrap s3c_pm_init() with s3c64xx_pm_init() which actually puts the device
> into the power domain after the machines have registered, looking for
> platform data to tell if the device was registered. Since currently only
> Cragganmore actually sets up PM that is the only machine updated.
>
> Signed-off-by: Mark Brown <broo...@opensource.wolfsonmicro.com>
> ---
...
> +
> +static int s3c64xx_pd_on(struct generic_pm_domain *domain)
> +{
> + struct s3c64xx_pm_domain *pd;
> + u32 val;
> + long retry = 1000000L;
> +
> + pd = container_of(domain, struct s3c64xx_pm_domain, pd);
> +
> + val = __raw_readl(S3C64XX_NORMAL_CFG);
> + val |= pd->ena;
> + __raw_writel(val, S3C64XX_NORMAL_CFG);
> +
> + /* Not all domains provide power status readback */
> + if (pd->pwr_stat) {
> + while (retry--)
> + if (__raw_readl(S3C64XX_BLK_PWR_STAT) & pd->pwr_stat)
> + break;
How about adding cpu_relax() in this busy wait loop ?
> + if (!retry) {
> + pr_err("Failed to start domain %s\n", pd->name);
> + return -EBUSY;
> + }
> + }
> +
> + return 0;
> +}
--
Regards,
Sylwester
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