[PATCHv9 8/8] ARM: OMAP4: USB: power down MUSB PHY if not used

[Felipe Balbi]

Hi,

On Thu, Oct 18, 2012 at 12:20:10PM +0300, Tero Kristo wrote:
> Commit c9e4412ab8eb8ef82d645d8749c4ce96ad490007 removed all of the USB
> PHY functions for OMAP4, but this causes a problem with core retention
> as the MUSB module remains enabled if omap-usb2 phy driver is not used.
> This keeps the USB DPLL enabled and prevents l3_init pwrdm from idling.
> 
> Fixed by adding a minimal function back that disables the USB PHY in
> case omap-usb2 driver is not used.
> 
> Signed-off-by: Tero Kristo <t-kristo at ti.com>
> Cc: Kishon Vijay Abraham I <kishon at ti.com>
> Cc: Felipe Balbi <balbi at ti.com>
> Cc: Tony Lindgren <tony at atomide.com>
> ---
>  arch/arm/mach-omap2/omap_phy_internal.c |   27 +++++++++++++++++++++++++++
>  1 files changed, 27 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/mach-omap2/omap_phy_internal.c b/arch/arm/mach-omap2/omap_phy_internal.c
> index d992db8..6a4b9cf 100644
> --- a/arch/arm/mach-omap2/omap_phy_internal.c
> +++ b/arch/arm/mach-omap2/omap_phy_internal.c
> @@ -33,6 +33,33 @@
>  #include "soc.h"
>  #include "control.h"
>  
> +#define CONTROL_DEV_CONF		0x300
> +#define PHY_PD				0x1
> +
> +#ifndef CONFIG_OMAP_USB2

this is a tristate, meaning that can be a module.

> +static int __init omap4430_phy_power_down(void)
> +{
> +	void __iomem *ctrl_base;
> +
> +	if (!cpu_is_omap44xx())
> +		return 0;
> +
> +	ctrl_base = ioremap(OMAP443X_SCM_BASE, SZ_1K);
> +	if (!ctrl_base) {
> +		pr_err("control module ioremap failed\n");
> +		return -ENOMEM;
> +	}
> +
> +	/* Power down the phy */
> +	__raw_writel(PHY_PD, ctrl_base + CONTROL_DEV_CONF);
> +
> +	iounmap(ctrl_base);
> +
> +	return 0;
> +}
> +early_initcall(omap4430_phy_power_down);
> +#endif

I think you could do it even if the driver is enabled.

Just to make sure I understand the issue right: is the PHY enabled by
default or did bootloader left this enabled ?

-- 
balbi
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