[PATCH] ARM: omap_hwmod: Add a new state to handle hwmods left enabled at init

[Govindraj]

On Thu, Nov 17, 2011 at 3:41 PM, Rajendra Nayak <rnayak at ti.com> wrote:
> A hwmod with a 'HWMOD_INIT_NO_IDLE' flag set, is left in
> enabled state by the hwmod framework post the initial setup.
> Once a real user of the device (a driver) tries to enable it
> at a later point, the hmwod framework throws a WARN() about
> the device being already in enabled state.
>
> Fix this by introducing a new state '_HWMOD_STATE_ENABLED_AT_INIT'
> to identify such devices/hwmods, so nothing but just a state
> change to '_HWMOD_STATE_ENABLED' can be done when the device/hwmod
> is requested to be enabled (the first time) by its driver/user.
>
> A good example of a such a device is an UART used as debug console.
> The UART module needs to be kept enabled through the boot, until the
> UART driver takes control of it, for debug prints to appear on
> the console.
>
> Signed-off-by: Rajendra Nayak <rnayak at ti.com>

tested with uart runtime v8 patch series works fine.
helps to simply the serial.c code without using custom console activate funcs.
thanks for handling this within the framework.

FWIW,

Tested-by: Govindraj.R <govindraj.raja at ti.com>

--
Thanks,
Govindraj.R


> ---
>  arch/arm/mach-omap2/omap_hwmod.c             |   16 ++++++++++++++--
>  arch/arm/plat-omap/include/plat/omap_hwmod.h |    1 +
>  2 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
> index d7f4623..7d94cc3 100644
> --- a/arch/arm/mach-omap2/omap_hwmod.c
> +++ b/arch/arm/mach-omap2/omap_hwmod.c
> @@ -1441,6 +1441,17 @@ static int _enable(struct omap_hwmod *oh)
>
>        pr_debug("omap_hwmod: %s: enabling\n", oh->name);
>
> +       /*
> +        * hwmods' with HWMOD_INIT_NO_IDLE flag set, are left
> +        * in enabled state at init.
> +        * Now that someone is really trying to enable them,
> +        * just update the state.
> +        */
> +       if (oh->_state == _HWMOD_STATE_ENABLED_AT_INIT) {
> +               oh->_state = _HWMOD_STATE_ENABLED;
> +               return 0;
> +       }
> +
>        if (oh->_state != _HWMOD_STATE_INITIALIZED &&
>            oh->_state != _HWMOD_STATE_IDLE &&
>            oh->_state != _HWMOD_STATE_DISABLED) {
> @@ -1449,7 +1460,6 @@ static int _enable(struct omap_hwmod *oh)
>                return -EINVAL;
>        }
>
> -
>        /*
>         * If an IP contains only one HW reset line, then de-assert it in order
>         * to allow the module state transition. Otherwise the PRCM will return
> @@ -1744,8 +1754,10 @@ static int _setup(struct omap_hwmod *oh, void *data)
>         * it should be set by the core code as a runtime flag during startup
>         */
>        if ((oh->flags & HWMOD_INIT_NO_IDLE) &&
> -           (postsetup_state == _HWMOD_STATE_IDLE))
> +           (postsetup_state == _HWMOD_STATE_IDLE)) {
> +               oh->_state = _HWMOD_STATE_ENABLED_AT_INIT;
>                postsetup_state = _HWMOD_STATE_ENABLED;
> +       }
>
>        if (postsetup_state == _HWMOD_STATE_IDLE)
>                _idle(oh);
> diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h b/arch/arm/plat-omap/include/plat/omap_hwmod.h
> index 1b81dfb..cd49d60 100644
> --- a/arch/arm/plat-omap/include/plat/omap_hwmod.h
> +++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h
> @@ -436,6 +436,7 @@ struct omap_hwmod_omap4_prcm {
>  #define _HWMOD_STATE_ENABLED                   4
>  #define _HWMOD_STATE_IDLE                      5
>  #define _HWMOD_STATE_DISABLED                  6
> +#define _HWMOD_STATE_ENABLED_AT_INIT           7
>
>  /**
>  * struct omap_hwmod_class - the type of an IP block
> --
> 1.7.1
>
> --
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