121 lines
4.3 KiB
C
121 lines
4.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __LINUX_GPIO_GENERIC_H
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#define __LINUX_GPIO_GENERIC_H
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#include <linux/cleanup.h>
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#include <linux/gpio/driver.h>
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#include <linux/spinlock.h>
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struct device;
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/**
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* struct gpio_generic_chip_config - Generic GPIO chip configuration data
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* @dev: Parent device of the new GPIO chip (compulsory).
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* @sz: Size (width) of the MMIO registers in bytes, typically 1, 2 or 4.
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* @dat: MMIO address for the register to READ the value of the GPIO lines, it
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* is expected that a 1 in the corresponding bit in this register means
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* the line is asserted.
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* @set: MMIO address for the register to SET the value of the GPIO lines, it
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* is expected that we write the line with 1 in this register to drive
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* the GPIO line high.
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* @clr: MMIO address for the register to CLEAR the value of the GPIO lines,
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* it is expected that we write the line with 1 in this register to
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* drive the GPIO line low. It is allowed to leave this address as NULL,
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* in that case the SET register will be assumed to also clear the GPIO
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* lines, by actively writing the line with 0.
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* @dirout: MMIO address for the register to set the line as OUTPUT. It is
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* assumed that setting a line to 1 in this register will turn that
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* line into an output line. Conversely, setting the line to 0 will
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* turn that line into an input.
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* @dirin: MMIO address for the register to set this line as INPUT. It is
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* assumed that setting a line to 1 in this register will turn that
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* line into an input line. Conversely, setting the line to 0 will
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* turn that line into an output.
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* @flags: Different flags that will affect the behaviour of the device, such
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* as endianness etc.
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*/
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struct gpio_generic_chip_config {
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struct device *dev;
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unsigned long sz;
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void __iomem *dat;
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void __iomem *set;
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void __iomem *clr;
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void __iomem *dirout;
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void __iomem *dirin;
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unsigned long flags;
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};
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/**
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* struct gpio_generic_chip - Generic GPIO chip implementation.
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* @gc: The underlying struct gpio_chip object, implementing low-level GPIO
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* chip routines.
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*/
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struct gpio_generic_chip {
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struct gpio_chip gc;
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};
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/**
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* gpio_generic_chip_init() - Initialize a generic GPIO chip.
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* @chip: Generic GPIO chip to set up.
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* @cfg: Generic GPIO chip configuration.
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*
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* Returns 0 on success, negative error number on failure.
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*/
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static inline int
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gpio_generic_chip_init(struct gpio_generic_chip *chip,
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const struct gpio_generic_chip_config *cfg)
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{
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return bgpio_init(&chip->gc, cfg->dev, cfg->sz, cfg->dat, cfg->set,
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cfg->clr, cfg->dirout, cfg->dirin, cfg->flags);
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}
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/**
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* gpio_generic_chip_set() - Set the GPIO line value of the generic GPIO chip.
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* @chip: Generic GPIO chip to use.
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* @offset: Hardware offset of the line to set.
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* @value: New GPIO line value.
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*
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* Some modules using the generic GPIO chip, need to set line values in their
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* direction setters but they don't have access to the gpio-mmio symbols so
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* they use the function pointer in struct gpio_chip directly. This is not
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* optimal and can lead to crashes at run-time in some instances. This wrapper
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* provides a safe interface for users.
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*
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* Returns: 0 on success, negative error number of failure.
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*/
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static inline int
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gpio_generic_chip_set(struct gpio_generic_chip *chip, unsigned int offset,
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int value)
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{
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if (WARN_ON(!chip->gc.set))
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return -EOPNOTSUPP;
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return chip->gc.set(&chip->gc, offset, value);
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}
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#define gpio_generic_chip_lock(gen_gc) \
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raw_spin_lock(&(gen_gc)->gc.bgpio_lock)
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#define gpio_generic_chip_unlock(gen_gc) \
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raw_spin_unlock(&(gen_gc)->gc.bgpio_lock)
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#define gpio_generic_chip_lock_irqsave(gen_gc, flags) \
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raw_spin_lock_irqsave(&(gen_gc)->gc.bgpio_lock, flags)
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#define gpio_generic_chip_unlock_irqrestore(gen_gc, flags) \
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raw_spin_unlock_irqrestore(&(gen_gc)->gc.bgpio_lock, flags)
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DEFINE_LOCK_GUARD_1(gpio_generic_lock,
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struct gpio_generic_chip,
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gpio_generic_chip_lock(_T->lock),
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gpio_generic_chip_unlock(_T->lock))
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DEFINE_LOCK_GUARD_1(gpio_generic_lock_irqsave,
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struct gpio_generic_chip,
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gpio_generic_chip_lock_irqsave(_T->lock, _T->flags),
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gpio_generic_chip_unlock_irqrestore(_T->lock, _T->flags),
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unsigned long flags)
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#endif /* __LINUX_GPIO_GENERIC_H */
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