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, 51 insertions, 0 deletions

diff --git a/drivers/gpio/gpiolib-shared.h b/drivers/gpio/gpiolib-shared.h
new file mode 100644
index 000000000..618756f6c
--- /dev/null
+++ b/drivers/gpio/gpiolib-shared.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __LINUX_GPIO_SHARED_H
+#define __LINUX_GPIO_SHARED_H
+
+#include <linux/mutex.h>
+
+struct gpio_device;
+struct gpio_desc;
+struct device;
+struct fwnode_handle;
+
+#if IS_ENABLED(CONFIG_GPIO_SHARED)
+
+int gpiochip_setup_shared(struct gpio_chip *gc);
+void gpio_device_teardown_shared(struct gpio_device *gdev);
+int gpio_shared_add_proxy_lookup(struct device *consumer,
+				 struct fwnode_handle *fwnode,
+				 const char *con_id, unsigned long lflags);
+
+#else
+
+static inline int gpiochip_setup_shared(struct gpio_chip *gc)
+{
+	return 0;
+}
+
+static inline void gpio_device_teardown_shared(struct gpio_device *gdev) { }
+
+static inline int gpio_shared_add_proxy_lookup(struct device *consumer,
+					       struct fwnode_handle *fwnode,
+					       const char *con_id,
+					       unsigned long lflags)
+{
+	return 0;
+}
+
+#endif /* CONFIG_GPIO_SHARED */
+
+struct gpio_shared_desc {
+	struct gpio_desc *desc;
+	unsigned long cfg;
+	unsigned int usecnt;
+	unsigned int votecnt;
+	int def_val;
+	struct mutex mutex; /* serializes all proxy operations on this descriptor */
+};
+
+struct gpio_shared_desc *devm_gpiod_shared_get(struct device *dev);
+
+#endif /* __LINUX_GPIO_SHARED_H */