Re: [Resend][PATCH 2/9] ACPI: Add acpi_pm_device_sleep_state helper routine

[Len Brown]

Ugh,
this breaks the build if CONFIG_ACPI_SLEEP=n

maybe it is time to delete the CONFIG_ACPI_SLEEP config option....

-Len

On Tuesday 17 July 2007 16:40, Rafael J. Wysocki wrote:
> From: Shaohua Li <shaohua.li@xxxxxxxxx>, Rafael J. Wysocki <rjw@xxxxxxx>
> 
> Based on the David Brownell's patch at
> http://marc.info/?l=linux-acpi&m=117873972806360&w=2
> 
> Add a helper routine returning the lowest power (highest number) ACPI device
> power state that given device can be in while the system is in the sleep state
> indicated by acpi_target_sleep_state .
> 
> Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
> Acked-by: Pavel Machek <pavel@xxxxxx>
> ---
>  drivers/acpi/sleep/main.c |   75 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/acpi/acpi_bus.h   |    2 +
>  2 files changed, 77 insertions(+)
> 
> Index: linux-2.6.22-git9/drivers/acpi/sleep/main.c
> ===================================================================
> --- linux-2.6.22-git9.orig/drivers/acpi/sleep/main.c
> +++ linux-2.6.22-git9/drivers/acpi/sleep/main.c
> @@ -255,6 +255,81 @@ static struct hibernation_ops acpi_hiber
>  };
>  #endif				/* CONFIG_SOFTWARE_SUSPEND */
>  
> +/**
> + *	acpi_pm_device_sleep_state - return preferred power state of ACPI device
> + *		in the system sleep state given by %acpi_target_sleep_state
> + *	@dev: device to examine
> + *	@wake: if set, the device should be able to wake up the system
> + *	@d_min_p: used to store the upper limit of allowed states range
> + *	Return value: preferred power state of the device on success, -ENODEV on
> + *		failure (ie. if there's no 'struct acpi_device' for @dev)
> + *
> + *	Find the lowest power (highest number) ACPI device power state that
> + *	device @dev can be in while the system is in the sleep state represented
> + *	by %acpi_target_sleep_state.  If @wake is nonzero, the device should be
> + *	able to wake up the system from this sleep state.  If @d_min_p is set,
> + *	the highest power (lowest number) device power state of @dev allowed
> + *	in this system sleep state is stored at the location pointed to by it.
> + *
> + *	The caller must ensure that @dev is valid before using this function.
> + *	The caller is also responsible for figuring out if the device is
> + *	supposed to be able to wake up the system and passing this information
> + *	via @wake.
> + */
> +
> +int acpi_pm_device_sleep_state(struct device *dev, int wake, int *d_min_p)
> +{
> +	acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
> +	struct acpi_device *adev;
> +	char acpi_method[] = "_SxD";
> +	unsigned long d_min, d_max;
> +
> +	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
> +		printk(KERN_ERR "ACPI handle has no context!\n");
> +		return -ENODEV;
> +	}
> +
> +	acpi_method[2] = '0' + acpi_target_sleep_state;
> +	/*
> +	 * If the sleep state is S0, we will return D3, but if the device has
> +	 * _S0W, we will use the value from _S0W
> +	 */
> +	d_min = ACPI_STATE_D0;
> +	d_max = ACPI_STATE_D3;
> +
> +	/*
> +	 * If present, _SxD methods return the minimum D-state (highest power
> +	 * state) we can use for the corresponding S-states.  Otherwise, the
> +	 * minimum D-state is D0 (ACPI 3.x).
> +	 *
> +	 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
> +	 * provided -- that's our fault recovery, we ignore retval.
> +	 */
> +	if (acpi_target_sleep_state > ACPI_STATE_S0)
> +		acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
> +
> +	/*
> +	 * If _PRW says we can wake up the system from the target sleep state,
> +	 * the D-state returned by _SxD is sufficient for that (we assume a
> +	 * wakeup-aware driver if wake is set).  Still, if _SxW exists
> +	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
> +	 * can wake the system.  _S0W may be valid, too.
> +	 */
> +	if (acpi_target_sleep_state == ACPI_STATE_S0 ||
> +	    (wake && adev->wakeup.state.enabled &&
> +	     adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
> +		acpi_method[3] = 'W';
> +		acpi_evaluate_integer(handle, acpi_method, NULL, &d_max);
> +		/* Sanity check */
> +		if (d_max < d_min)
> +			d_min = d_max;
> +	}
> +
> +	if (d_min_p)
> +		*d_min_p = d_min;
> +	return d_max;
> +}
> +
>  /*
>   * Toshiba fails to preserve interrupts over S1, reinitialization
>   * of 8259 is needed after S1 resume.
> Index: linux-2.6.22-git9/include/acpi/acpi_bus.h
> ===================================================================
> --- linux-2.6.22-git9.orig/include/acpi/acpi_bus.h
> +++ linux-2.6.22-git9/include/acpi/acpi_bus.h
> @@ -364,6 +364,8 @@ acpi_handle acpi_get_child(acpi_handle, 
>  acpi_handle acpi_get_pci_rootbridge_handle(unsigned int, unsigned int);
>  #define DEVICE_ACPI_HANDLE(dev) ((acpi_handle)((dev)->archdata.acpi_handle))
>  
> +int acpi_pm_device_sleep_state(struct device *, int, int *);
> +
>  #endif				/* CONFIG_ACPI */
>  
>  #endif /*__ACPI_BUS_H__*/
> 
> -
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