PCI: Add pci_irq_type() to query the allocated interrupt typegrafted

Add a helper that returns PCI_IRQ_MSIX, PCI_IRQ_MSI, or PCI_IRQ_INTX
based on the interrupt type the PCI core selected after
pci_alloc_irq_vectors().

Several drivers already open-code this check against pdev->msix_enabled
and pdev->msi_enabled, or even open code this helper [1].

A common helper avoids the duplication and keeps drivers from accessing
the bitfield directly (see also [2]).

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Link: https://elixir.bootlin.com/linux/v7.1/source/drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c#L196 [1]
Inspired-by: John Hubbard <jhubbard@nvidia.com>
Link: https://lore.kernel.org/all/DKKG2QM3YJYB.Z2H2B2UXJ75N@kernel.org/ [2]
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260813165234.620555-5-dakr@kernel.org
[ Add missing pci_irq_type() stub for CONFIG_PCI=n. ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

1 files changed, 186 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-backlight b/Documentation/ABI/testing/sysfs-class-backlight
new file mode 100644
index 000000000..c453646b0
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-backlight
@@ -0,0 +1,186 @@
+What:		/sys/class/backlight/<backlight>/scale
+Date:		July 2019
+KernelVersion:	5.4
+Contact:	Daniel Thompson <daniel.thompson@linaro.org>
+Description:
+		Description of the scale of the brightness curve.
+
+		The human eye senses brightness approximately logarithmically,
+		hence linear changes in brightness are perceived as being
+		non-linear. To achieve a linear perception of brightness changes
+		controls like sliders need to apply a logarithmic mapping for
+		backlights with a linear brightness curve.
+
+		Possible values of the attribute are:
+
+		unknown
+		  The scale of the brightness curve is unknown.
+
+		linear
+		  The brightness changes linearly with each step. Brightness
+		  controls should apply a logarithmic mapping for a linear
+		  perception.
+
+		non-linear
+		  The brightness changes non-linearly with each step. Brightness
+		  controls should use a linear mapping for a linear perception.
+
+What:		/sys/class/backlight/<backlight>/ambient_light_level
+Date:		Apr, 2010
+KernelVersion:	v2.6.35
+Contact:	Michael Hennerich <michael.hennerich@analog.com>
+Description:
+		(RO) Get conversion value of the light sensor.
+
+		The value is automatically updated every 80 ms when the
+		light sensor is enabled.
+
+		The value range is device-driver specific:
+
+		For ADP8870:
+
+		  It returns integer between 0 (dark) and 8000 (max ambient
+		  brightness).
+
+		For ADP8860:
+
+		  It returns a 13-bits integer.
+
+What:		/sys/class/backlight/<backlight>/ambient_light_zone
+Date:		Apr, 2010
+KernelVersion:	v2.6.35
+Contact:	Michael Hennerich <michael.hennerich@analog.com>,
+		device-drivers-devel@blackfin.uclinux.org
+
+Description:
+		(RW) Read or write the specific brightness level at which the
+		backlight operates.
+
+		The value meaning is device-driver specific:
+
+		For ADP8860:
+
+		  ==	==========================
+		   0	Off: Backlight set to 0 mA
+		   1	Level 1: daylight
+		   2	Level 2: bright
+		   3	Level 3: dark
+		  ==	==========================
+
+		For ADP8870:
+
+		  ==	==========================
+		   0	Off: Backlight set to 0 mA
+		   1	Level 1: daylight
+		   2	Level 2: bright
+		   3	Level 3: office
+		   4	Level 4: indoor
+		   5	Level 5: dark
+		  ==	==========================
+
+		Writing 0 returns to normal/automatic ambient light level
+		operation.
+
+		It can be enabled by writing the value stored in
+		/sys/class/backlight/<backlight>/max_brightness to
+		/sys/class/backlight/<backlight>/brightness.
+
+What:		/sys/class/backlight/<backlight>/<ambient light zone>_max
+Date:		Sep, 2009
+KernelVersion:	v2.6.32
+Contact:	device-drivers-devel@blackfin.uclinux.org
+Description:
+		Control the maximum brightness for <ambient light zone>
+		on this <backlight>. Values are between 0 and 127. This file
+		will also show the brightness level stored for this
+		<ambient light zone>.
+
+		The <ambient light zone> is device-driver specific:
+
+		For ADP5520 and ADP5501, <ambient light zone> can be:
+
+		===========  ================================================
+		Ambient      sysfs entry
+		light zone
+		===========  ================================================
+		daylight     /sys/class/backlight/<backlight>/daylight_max
+		office       /sys/class/backlight/<backlight>/office_max
+		dark         /sys/class/backlight/<backlight>/dark_max
+		===========  ================================================
+
+		For ADP8860, <ambient light zone> can be:
+
+		===========  ================================================
+		Ambient      sysfs entry
+		light zone
+		===========  ================================================
+		l1_daylight  /sys/class/backlight/<backlight>/l1_daylight_max
+		l2_office    /sys/class/backlight/<backlight>/l2_office_max
+		l3_dark      /sys/class/backlight/<backlight>/l3_dark_max
+		===========  ================================================
+
+		For ADP8870, <ambient light zone> can be:
+
+		===========  ================================================
+		Ambient      sysfs entry
+		light zone
+		===========  ================================================
+		l1_daylight  /sys/class/backlight/<backlight>/l1_daylight_max
+		l2_bright    /sys/class/backlight/<backlight>/l2_bright_max
+		l3_office    /sys/class/backlight/<backlight>/l3_office_max
+		l4_indoor    /sys/class/backlight/<backlight>/l4_indoor_max
+		l5_dark      /sys/class/backlight/<backlight>/l5_dark_max
+		===========  ================================================
+
+		See also: /sys/class/backlight/<backlight>/ambient_light_zone.
+
+What:		/sys/class/backlight/<backlight>/<ambient light zone>_dim
+Date:		Sep, 2009
+KernelVersion:	v2.6.32
+Contact:	device-drivers-devel@blackfin.uclinux.org
+Description:
+		Control the dim brightness for <ambient light zone>
+		on this <backlight>. Values are between 0 and 127, typically
+		set to 0. Full off when the backlight is disabled.
+		This file will also show the dim brightness level stored for
+		this <ambient light zone>.
+
+		The <ambient light zone> is device-driver specific:
+
+		For ADP5520 and ADP5501, <ambient light zone> can be:
+
+		===========  ================================================
+		Ambient      sysfs entry
+		light zone
+		===========  ================================================
+		daylight     /sys/class/backlight/<backlight>/daylight_dim
+		office       /sys/class/backlight/<backlight>/office_dim
+		dark         /sys/class/backlight/<backlight>/dark_dim
+		===========  ================================================
+
+		For ADP8860, <ambient light zone> can be:
+
+		===========  ================================================
+		Ambient      sysfs entry
+		light zone
+		===========  ================================================
+		l1_daylight  /sys/class/backlight/<backlight>/l1_daylight_dim
+		l2_office    /sys/class/backlight/<backlight>/l2_office_dim
+		l3_dark      /sys/class/backlight/<backlight>/l3_dark_dim
+		===========  ================================================
+
+		For ADP8870, <ambient light zone> can be:
+
+		===========  ================================================
+		Ambient      sysfs entry
+		light zone
+		===========  ================================================
+		l1_daylight  /sys/class/backlight/<backlight>/l1_daylight_dim
+		l2_bright    /sys/class/backlight/<backlight>/l2_bright_dim
+		l3_office    /sys/class/backlight/<backlight>/l3_office_dim
+		l4_indoor    /sys/class/backlight/<backlight>/l4_indoor_dim
+		l5_dark      /sys/class/backlight/<backlight>/l5_dark_dim
+		===========  ================================================
+
+		See also: /sys/class/backlight/<backlight>/ambient_light_zone.
+