gpio: move gpio-mmio-specific fields out of struct gpio_chip

With all users of bgpio_init() converted to using the modernized generic
GPIO chip API, we can now move the gpio-mmio-specific fields out of
struct gpio_chip and into the dedicated struct gpio_generic_chip. To
that end: adjust the gpio-mmio driver to the new layout, update the
docs, etc.

The changes in gpio-mlxbf2.c and gpio-mpc8xxx.c are here and not in their
respective conversion commits because the former passes the address of
the generic chip's lock to the __releases() annotation and we cannot
really hide it while gpio-mpc8xxx.c accesses the shadow registers in a
driver-specific workaround and there's no reason to make them available
in a public API.

Also: drop the relevant task from TODO as it's now done.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250910-gpio-mmio-gpio-conv-part4-v2-15-f3d1a4c57124@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

1 files changed, 0 insertions, 44 deletions

diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 9fcd4a988081..9b14fd20f13e 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -388,28 +388,6 @@ struct gpio_irq_chip {
  *	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_out: direction out setting register for generic GPIO
- * @reg_dir_in: direction in setting register for generic GPIO
- * @bgpio_dir_unreadable: indicates that the direction register(s) cannot
- *	be read and we need to rely on out internal state tracking.
- * @bgpio_pinctrl: the generic GPIO uses a pin control backend.
- * @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 "1" in this word means the line is set as
- *	output.
  *
  * A gpio_chip can help platforms abstract various sources of GPIOs so
  * they can all be accessed through a common programming interface.
@@ -475,23 +453,6 @@ struct gpio_chip {
 	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_out;
-	void __iomem *reg_dir_in;
-	bool bgpio_dir_unreadable;
-	bool bgpio_pinctrl;
-	int bgpio_bits;
-	raw_spinlock_t bgpio_lock;
-	unsigned long bgpio_data;
-	unsigned long bgpio_dir;
-#endif /* CONFIG_GPIO_GENERIC */
-
 #ifdef CONFIG_GPIOLIB_IRQCHIP
 	/*
 	 * With CONFIG_GPIOLIB_IRQCHIP we get an irqchip inside the gpiolib
@@ -723,11 +684,6 @@ int gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
 
 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
 
-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 */