Re: regulator: Add disable_on_boot flag to constraints.

[Jonathan Cameron <Jonathan.Cameron@gmail.com>]

Dear All,

I'd forgotten about this one until I tried to clean up a patch dependent
on it.

Any more comments / requested changes?

If anyone wants this rebased against a current tree just ask.
( I don't think it ended up in any relevant trees.  Sorry if I've just
missed it!)

Thanks,

Jonathan
> From: Jonathan Cameron <jic23@cam.ac.uk>
>
> regulator: Add disable_on_boot flag to constraints.
>
> Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
> ---
> Now based on voltage / for-next and with kernel doc
> added.
>
> Not quite sure what trashed the previous patch, but
> hopefully this one should work.
>
> Changes in response to Mark Browns comments.
>
> Patch changed to disable_on_boot for more flexibility.
> This only really involved removing the check in the enable code
> found in the previous patch.
>
> This is intended to allow the disabling of regulators during
> registration.  Typical use case is regulators that aren't
> actually connected to anything.
>
> This is against a clean voltage for-next with Mark's 
> hoisting of struct regulator_dev patch applied. (not that
> it materially changes this patch).
>
>  drivers/regulator/core.c          |   19 ++++++++++++++++++-
>  include/linux/regulator/machine.h |    9 ++++++---
>  2 files changed, 24 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
> index 0ed13c2..ea7caaf 100644
> --- a/drivers/regulator/core.c
> +++ b/drivers/regulator/core.c
> @@ -723,7 +723,14 @@ static int set_machine_constraints(struct regulator_dev *rdev,
>  			goto out;
>  		}
>  	}
> -
> +	/* Sanity check */
> +	if (constraints->always_on && constraints->disable_on_boot) {
> +		printk(KERN_ERR "%s: always on and disable at boot both set for %s\n",
> +		       __func__, name);
> +		rdev->constraints = NULL;
> +		ret = -EINVAL;
> +		goto out;
> +	}
>  	/* if always_on is set then turn the regulator on if it's not
>  	 * already on. */
>  	if (constraints->always_on && ops->enable &&
> @@ -736,6 +743,16 @@ static int set_machine_constraints(struct regulator_dev *rdev,
>  			rdev->constraints = NULL;
>  			goto out;
>  		}
> +	} else if (constraints->disable_on_boot && ops->disable &&
> +		   ((ops->is_enabled && ops->is_enabled(rdev)) ||
> +		    (!ops->is_enabled && constraints->boot_on))) {
> +		ret = ops->disable(rdev);
> +		if (ret < 0) {
> +			printk(KERN_ERR "%s: failed to disable %s\n",
> +			       __func__, name);
> +			rdev->constraints = NULL;
> +			goto out;
> +		}
>  	}
>  
>  	print_constraints(rdev);
> diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h
> index 3794773..f7d01dd 100644
> --- a/include/linux/regulator/machine.h
> +++ b/include/linux/regulator/machine.h
> @@ -74,6 +74,8 @@ struct regulator_state {
>   * @always_on: Set if the regulator should never be disabled.
>   * @boot_on: Set if the regulator is enabled when the system is initially
>   *           started.
> + * @disable_on_boot: Set if the regulator should be disabled. Typically
> + *                   for regulators that are not connected.
>   * @apply_uV: Apply the voltage constraint when initialising.
>   *
>   * @input_uV: Input voltage for regulator when supplied by another regulator.
> @@ -112,9 +114,10 @@ struct regulation_constraints {
>  	suspend_state_t initial_state; /* suspend state to set at init */
>  
>  	/* constriant flags */
> -	unsigned always_on:1;	/* regulator never off when system is on */
> -	unsigned boot_on:1;	/* bootloader/firmware enabled regulator */
> -	unsigned apply_uV:1;	/* apply uV constraint iff min == max */
> +	unsigned always_on:1;		/* regulator never off when system on */
> +	unsigned boot_on:1;		/* bootloader/firmware enabled reg */
> +	unsigned disable_on_boot:1;	/* regulator to be disabled at boot */
> +	unsigned apply_uV:1;		/* apply uV constraint iff min == max */
>  };
>  
>  /**
>