v4.19.13 snapshot.
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
new file mode 100644
index 0000000..a4d5eb3
--- /dev/null
+++ b/include/linux/gpio/driver.h
@@ -0,0 +1,594 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_GPIO_DRIVER_H
+#define __LINUX_GPIO_DRIVER_H
+
+#include <linux/device.h>
+#include <linux/types.h>
+#include <linux/irq.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/lockdep.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinconf-generic.h>
+
+struct gpio_desc;
+struct of_phandle_args;
+struct device_node;
+struct seq_file;
+struct gpio_device;
+struct module;
+
+#ifdef CONFIG_GPIOLIB
+
+#ifdef CONFIG_GPIOLIB_IRQCHIP
+/**
+ * struct gpio_irq_chip - GPIO interrupt controller
+ */
+struct gpio_irq_chip {
+	/**
+	 * @chip:
+	 *
+	 * GPIO IRQ chip implementation, provided by GPIO driver.
+	 */
+	struct irq_chip *chip;
+
+	/**
+	 * @domain:
+	 *
+	 * Interrupt translation domain; responsible for mapping between GPIO
+	 * hwirq number and Linux IRQ number.
+	 */
+	struct irq_domain *domain;
+
+	/**
+	 * @domain_ops:
+	 *
+	 * Table of interrupt domain operations for this IRQ chip.
+	 */
+	const struct irq_domain_ops *domain_ops;
+
+	/**
+	 * @handler:
+	 *
+	 * The IRQ handler to use (often a predefined IRQ core function) for
+	 * GPIO IRQs, provided by GPIO driver.
+	 */
+	irq_flow_handler_t handler;
+
+	/**
+	 * @default_type:
+	 *
+	 * Default IRQ triggering type applied during GPIO driver
+	 * initialization, provided by GPIO driver.
+	 */
+	unsigned int default_type;
+
+	/**
+	 * @lock_key:
+	 *
+	 * Per GPIO IRQ chip lockdep classes.
+	 */
+	struct lock_class_key *lock_key;
+	struct lock_class_key *request_key;
+
+	/**
+	 * @parent_handler:
+	 *
+	 * The interrupt handler for the GPIO chip's parent interrupts, may be
+	 * NULL if the parent interrupts are nested rather than cascaded.
+	 */
+	irq_flow_handler_t parent_handler;
+
+	/**
+	 * @parent_handler_data:
+	 *
+	 * Data associated, and passed to, the handler for the parent
+	 * interrupt.
+	 */
+	void *parent_handler_data;
+
+	/**
+	 * @num_parents:
+	 *
+	 * The number of interrupt parents of a GPIO chip.
+	 */
+	unsigned int num_parents;
+
+	/**
+	 * @parent_irq:
+	 *
+	 * For use by gpiochip_set_cascaded_irqchip()
+	 */
+	unsigned int parent_irq;
+
+	/**
+	 * @parents:
+	 *
+	 * A list of interrupt parents of a GPIO chip. This is owned by the
+	 * driver, so the core will only reference this list, not modify it.
+	 */
+	unsigned int *parents;
+
+	/**
+	 * @map:
+	 *
+	 * A list of interrupt parents for each line of a GPIO chip.
+	 */
+	unsigned int *map;
+
+	/**
+	 * @threaded:
+	 *
+	 * True if set the interrupt handling uses nested threads.
+	 */
+	bool threaded;
+
+	/**
+	 * @need_valid_mask:
+	 *
+	 * If set core allocates @valid_mask with all bits set to one.
+	 */
+	bool need_valid_mask;
+
+	/**
+	 * @valid_mask:
+	 *
+	 * If not %NULL holds bitmask of GPIOs which are valid to be included
+	 * in IRQ domain of the chip.
+	 */
+	unsigned long *valid_mask;
+
+	/**
+	 * @first:
+	 *
+	 * Required for static IRQ allocation. If set, irq_domain_add_simple()
+	 * will allocate and map all IRQs during initialization.
+	 */
+	unsigned int first;
+};
+
+static inline struct gpio_irq_chip *to_gpio_irq_chip(struct irq_chip *chip)
+{
+	return container_of(chip, struct gpio_irq_chip, chip);
+}
+#endif
+
+/**
+ * struct gpio_chip - abstract a GPIO controller
+ * @label: a functional name for the GPIO device, such as a part
+ *	number or the name of the SoC IP-block implementing it.
+ * @gpiodev: the internal state holder, opaque struct
+ * @parent: optional parent device providing the GPIOs
+ * @owner: helps prevent removal of modules exporting active GPIOs
+ * @request: optional hook for chip-specific activation, such as
+ *	enabling module power and clock; may sleep
+ * @free: optional hook for chip-specific deactivation, such as
+ *	disabling module power and clock; may sleep
+ * @get_direction: returns direction for signal "offset", 0=out, 1=in,
+ *	(same as GPIOF_DIR_XXX), or negative error
+ * @direction_input: configures signal "offset" as input, or returns error
+ * @direction_output: configures signal "offset" as output, or returns error
+ * @get: returns value for signal "offset", 0=low, 1=high, or negative error
+ * @get_multiple: reads values for multiple signals defined by "mask" and
+ *	stores them in "bits", returns 0 on success or negative error
+ * @set: assigns output value for signal "offset"
+ * @set_multiple: assigns output values for multiple signals defined by "mask"
+ * @set_config: optional hook for all kinds of settings. Uses the same
+ *	packed config format as generic pinconf.
+ * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
+ *	implementation may not sleep
+ * @dbg_show: optional routine to show contents in debugfs; default code
+ *	will be used when this is omitted, but custom code can show extra
+ *	state (such as pullup/pulldown configuration).
+ * @base: identifies the first GPIO number handled by this chip;
+ *	or, if negative during registration, requests dynamic ID allocation.
+ *	DEPRECATION: providing anything non-negative and nailing the base
+ *	offset of GPIO chips is deprecated. Please pass -1 as base to
+ *	let gpiolib select the chip base in all possible cases. We want to
+ *	get rid of the static GPIO number space in the long run.
+ * @ngpio: the number of GPIOs handled by this controller; the last GPIO
+ *	handled is (base + ngpio - 1).
+ * @names: if set, must be an array of strings to use as alternative
+ *      names for the GPIOs in this chip. Any entry in the array
+ *      may be NULL if there is no alias for the GPIO, however the
+ *      array must be @ngpio entries long.  A name can include a single printk
+ *      format specifier for an unsigned int.  It is substituted by the actual
+ *      number of the gpio.
+ * @can_sleep: flag must be set iff get()/set() methods sleep, as they
+ *	must while accessing GPIO expander chips over I2C or SPI. This
+ *	implies that if the chip supports IRQs, these IRQs need to be threaded
+ *	as the chip access may sleep when e.g. reading out the IRQ status
+ *	registers.
+ * @read_reg: reader function for generic GPIO
+ * @write_reg: writer function for generic GPIO
+ * @be_bits: if the generic GPIO has big endian bit order (bit 31 is representing
+ *	line 0, bit 30 is line 1 ... bit 0 is line 31) this is set to true by the
+ *	generic GPIO core. It is for internal housekeeping only.
+ * @reg_dat: data (in) register for generic GPIO
+ * @reg_set: output set register (out=high) for generic GPIO
+ * @reg_clr: output clear register (out=low) for generic GPIO
+ * @reg_dir: direction setting register for generic GPIO
+ * @bgpio_dir_inverted: indicates that the direction register is inverted
+ *	(gpiolib private state variable)
+ * @bgpio_bits: number of register bits used for a generic GPIO i.e.
+ *	<register width> * 8
+ * @bgpio_lock: used to lock chip->bgpio_data. Also, this is needed to keep
+ *	shadowed and real data registers writes together.
+ * @bgpio_data:	shadowed data register for generic GPIO to clear/set bits
+ *	safely.
+ * @bgpio_dir: shadowed direction register for generic GPIO to clear/set
+ *	direction safely.
+ *
+ * A gpio_chip can help platforms abstract various sources of GPIOs so
+ * they can all be accessed through a common programing interface.
+ * Example sources would be SOC controllers, FPGAs, multifunction
+ * chips, dedicated GPIO expanders, and so on.
+ *
+ * Each chip controls a number of signals, identified in method calls
+ * by "offset" values in the range 0..(@ngpio - 1).  When those signals
+ * are referenced through calls like gpio_get_value(gpio), the offset
+ * is calculated by subtracting @base from the gpio number.
+ */
+struct gpio_chip {
+	const char		*label;
+	struct gpio_device	*gpiodev;
+	struct device		*parent;
+	struct module		*owner;
+
+	int			(*request)(struct gpio_chip *chip,
+						unsigned offset);
+	void			(*free)(struct gpio_chip *chip,
+						unsigned offset);
+	int			(*get_direction)(struct gpio_chip *chip,
+						unsigned offset);
+	int			(*direction_input)(struct gpio_chip *chip,
+						unsigned offset);
+	int			(*direction_output)(struct gpio_chip *chip,
+						unsigned offset, int value);
+	int			(*get)(struct gpio_chip *chip,
+						unsigned offset);
+	int			(*get_multiple)(struct gpio_chip *chip,
+						unsigned long *mask,
+						unsigned long *bits);
+	void			(*set)(struct gpio_chip *chip,
+						unsigned offset, int value);
+	void			(*set_multiple)(struct gpio_chip *chip,
+						unsigned long *mask,
+						unsigned long *bits);
+	int			(*set_config)(struct gpio_chip *chip,
+					      unsigned offset,
+					      unsigned long config);
+	int			(*to_irq)(struct gpio_chip *chip,
+						unsigned offset);
+
+	void			(*dbg_show)(struct seq_file *s,
+						struct gpio_chip *chip);
+	int			base;
+	u16			ngpio;
+	const char		*const *names;
+	bool			can_sleep;
+
+#if IS_ENABLED(CONFIG_GPIO_GENERIC)
+	unsigned long (*read_reg)(void __iomem *reg);
+	void (*write_reg)(void __iomem *reg, unsigned long data);
+	bool be_bits;
+	void __iomem *reg_dat;
+	void __iomem *reg_set;
+	void __iomem *reg_clr;
+	void __iomem *reg_dir;
+	bool bgpio_dir_inverted;
+	int bgpio_bits;
+	spinlock_t bgpio_lock;
+	unsigned long bgpio_data;
+	unsigned long bgpio_dir;
+#endif
+
+#ifdef CONFIG_GPIOLIB_IRQCHIP
+	/*
+	 * With CONFIG_GPIOLIB_IRQCHIP we get an irqchip inside the gpiolib
+	 * to handle IRQs for most practical cases.
+	 */
+
+	/**
+	 * @irq:
+	 *
+	 * Integrates interrupt chip functionality with the GPIO chip. Can be
+	 * used to handle IRQs for most practical cases.
+	 */
+	struct gpio_irq_chip irq;
+#endif
+
+	/**
+	 * @need_valid_mask:
+	 *
+	 * If set core allocates @valid_mask with all bits set to one.
+	 */
+	bool need_valid_mask;
+
+	/**
+	 * @valid_mask:
+	 *
+	 * If not %NULL holds bitmask of GPIOs which are valid to be used
+	 * from the chip.
+	 */
+	unsigned long *valid_mask;
+
+#if defined(CONFIG_OF_GPIO)
+	/*
+	 * If CONFIG_OF is enabled, then all GPIO controllers described in the
+	 * device tree automatically may have an OF translation
+	 */
+
+	/**
+	 * @of_node:
+	 *
+	 * Pointer to a device tree node representing this GPIO controller.
+	 */
+	struct device_node *of_node;
+
+	/**
+	 * @of_gpio_n_cells:
+	 *
+	 * Number of cells used to form the GPIO specifier.
+	 */
+	unsigned int of_gpio_n_cells;
+
+	/**
+	 * @of_xlate:
+	 *
+	 * Callback to translate a device tree GPIO specifier into a chip-
+	 * relative GPIO number and flags.
+	 */
+	int (*of_xlate)(struct gpio_chip *gc,
+			const struct of_phandle_args *gpiospec, u32 *flags);
+#endif
+};
+
+extern const char *gpiochip_is_requested(struct gpio_chip *chip,
+			unsigned offset);
+
+/* add/remove chips */
+extern int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
+				      struct lock_class_key *lock_key,
+				      struct lock_class_key *request_key);
+
+/**
+ * gpiochip_add_data() - register a gpio_chip
+ * @chip: the chip to register, with chip->base initialized
+ * @data: driver-private data associated with this chip
+ *
+ * Context: potentially before irqs will work
+ *
+ * When gpiochip_add_data() is called very early during boot, so that GPIOs
+ * can be freely used, the chip->parent device must be registered before
+ * the gpio framework's arch_initcall().  Otherwise sysfs initialization
+ * for GPIOs will fail rudely.
+ *
+ * gpiochip_add_data() must only be called after gpiolib initialization,
+ * ie after core_initcall().
+ *
+ * If chip->base is negative, this requests dynamic assignment of
+ * a range of valid GPIOs.
+ *
+ * Returns:
+ * A negative errno if the chip can't be registered, such as because the
+ * chip->base is invalid or already associated with a different chip.
+ * Otherwise it returns zero as a success code.
+ */
+#ifdef CONFIG_LOCKDEP
+#define gpiochip_add_data(chip, data) ({		\
+		static struct lock_class_key lock_key;	\
+		static struct lock_class_key request_key;	  \
+		gpiochip_add_data_with_key(chip, data, &lock_key, \
+					   &request_key);	  \
+	})
+#else
+#define gpiochip_add_data(chip, data) gpiochip_add_data_with_key(chip, data, NULL, NULL)
+#endif
+
+static inline int gpiochip_add(struct gpio_chip *chip)
+{
+	return gpiochip_add_data(chip, NULL);
+}
+extern void gpiochip_remove(struct gpio_chip *chip);
+extern int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
+				  void *data);
+extern void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip);
+
+extern struct gpio_chip *gpiochip_find(void *data,
+			      int (*match)(struct gpio_chip *chip, void *data));
+
+/* lock/unlock as IRQ */
+int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
+void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
+bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset);
+
+/* Line status inquiry for drivers */
+bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset);
+bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset);
+
+/* Sleep persistence inquiry for drivers */
+bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset);
+bool gpiochip_line_is_valid(const struct gpio_chip *chip, unsigned int offset);
+
+/* get driver data */
+void *gpiochip_get_data(struct gpio_chip *chip);
+
+struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
+
+struct bgpio_pdata {
+	const char *label;
+	int base;
+	int ngpio;
+};
+
+#if IS_ENABLED(CONFIG_GPIO_GENERIC)
+
+int bgpio_init(struct gpio_chip *gc, struct device *dev,
+	       unsigned long sz, void __iomem *dat, void __iomem *set,
+	       void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
+	       unsigned long flags);
+
+#define BGPIOF_BIG_ENDIAN		BIT(0)
+#define BGPIOF_UNREADABLE_REG_SET	BIT(1) /* reg_set is unreadable */
+#define BGPIOF_UNREADABLE_REG_DIR	BIT(2) /* reg_dir is unreadable */
+#define BGPIOF_BIG_ENDIAN_BYTE_ORDER	BIT(3)
+#define BGPIOF_READ_OUTPUT_REG_SET	BIT(4) /* reg_set stores output value */
+#define BGPIOF_NO_OUTPUT		BIT(5) /* only input */
+
+#endif
+
+#ifdef CONFIG_GPIOLIB_IRQCHIP
+
+int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
+		     irq_hw_number_t hwirq);
+void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq);
+
+void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
+		struct irq_chip *irqchip,
+		unsigned int parent_irq,
+		irq_flow_handler_t parent_handler);
+
+void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
+		struct irq_chip *irqchip,
+		unsigned int parent_irq);
+
+int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
+			     struct irq_chip *irqchip,
+			     unsigned int first_irq,
+			     irq_flow_handler_t handler,
+			     unsigned int type,
+			     bool threaded,
+			     struct lock_class_key *lock_key,
+			     struct lock_class_key *request_key);
+
+bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
+				unsigned int offset);
+
+#ifdef CONFIG_LOCKDEP
+
+/*
+ * Lockdep requires that each irqchip instance be created with a
+ * unique key so as to avoid unnecessary warnings. This upfront
+ * boilerplate static inlines provides such a key for each
+ * unique instance.
+ */
+static inline int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
+				       struct irq_chip *irqchip,
+				       unsigned int first_irq,
+				       irq_flow_handler_t handler,
+				       unsigned int type)
+{
+	static struct lock_class_key lock_key;
+	static struct lock_class_key request_key;
+
+	return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
+					handler, type, false,
+					&lock_key, &request_key);
+}
+
+static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
+			  struct irq_chip *irqchip,
+			  unsigned int first_irq,
+			  irq_flow_handler_t handler,
+			  unsigned int type)
+{
+
+	static struct lock_class_key lock_key;
+	static struct lock_class_key request_key;
+
+	return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
+					handler, type, true,
+					&lock_key, &request_key);
+}
+#else
+static inline int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
+				       struct irq_chip *irqchip,
+				       unsigned int first_irq,
+				       irq_flow_handler_t handler,
+				       unsigned int type)
+{
+	return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
+					handler, type, false, NULL, NULL);
+}
+
+static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
+			  struct irq_chip *irqchip,
+			  unsigned int first_irq,
+			  irq_flow_handler_t handler,
+			  unsigned int type)
+{
+	return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
+					handler, type, true, NULL, NULL);
+}
+#endif /* CONFIG_LOCKDEP */
+
+#endif /* CONFIG_GPIOLIB_IRQCHIP */
+
+int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset);
+void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset);
+int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
+			    unsigned long config);
+
+#ifdef CONFIG_PINCTRL
+
+/**
+ * struct gpio_pin_range - pin range controlled by a gpio chip
+ * @node: list for maintaining set of pin ranges, used internally
+ * @pctldev: pinctrl device which handles corresponding pins
+ * @range: actual range of pins controlled by a gpio controller
+ */
+struct gpio_pin_range {
+	struct list_head node;
+	struct pinctrl_dev *pctldev;
+	struct pinctrl_gpio_range range;
+};
+
+int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
+			   unsigned int gpio_offset, unsigned int pin_offset,
+			   unsigned int npins);
+int gpiochip_add_pingroup_range(struct gpio_chip *chip,
+			struct pinctrl_dev *pctldev,
+			unsigned int gpio_offset, const char *pin_group);
+void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
+
+#else
+
+static inline int
+gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
+		       unsigned int gpio_offset, unsigned int pin_offset,
+		       unsigned int npins)
+{
+	return 0;
+}
+static inline int
+gpiochip_add_pingroup_range(struct gpio_chip *chip,
+			struct pinctrl_dev *pctldev,
+			unsigned int gpio_offset, const char *pin_group)
+{
+	return 0;
+}
+
+static inline void
+gpiochip_remove_pin_ranges(struct gpio_chip *chip)
+{
+}
+
+#endif /* CONFIG_PINCTRL */
+
+struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
+					    const char *label);
+void gpiochip_free_own_desc(struct gpio_desc *desc);
+
+#else /* CONFIG_GPIOLIB */
+
+static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
+{
+	/* GPIO can never have been requested */
+	WARN_ON(1);
+	return ERR_PTR(-ENODEV);
+}
+
+#endif /* CONFIG_GPIOLIB */
+
+#endif