Linux kernel mirror (for testing)
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2
3#ifndef __LINUX_GPIO_GENERIC_H
4#define __LINUX_GPIO_GENERIC_H
5
6#include <linux/cleanup.h>
7#include <linux/gpio/driver.h>
8#include <linux/spinlock.h>
9
10struct device;
11
12/**
13 * struct gpio_generic_chip_config - Generic GPIO chip configuration data
14 * @dev: Parent device of the new GPIO chip (compulsory).
15 * @sz: Size (width) of the MMIO registers in bytes, typically 1, 2 or 4.
16 * @dat: MMIO address for the register to READ the value of the GPIO lines, it
17 * is expected that a 1 in the corresponding bit in this register means
18 * the line is asserted.
19 * @set: MMIO address for the register to SET the value of the GPIO lines, it
20 * is expected that we write the line with 1 in this register to drive
21 * the GPIO line high.
22 * @clr: MMIO address for the register to CLEAR the value of the GPIO lines,
23 * it is expected that we write the line with 1 in this register to
24 * drive the GPIO line low. It is allowed to leave this address as NULL,
25 * in that case the SET register will be assumed to also clear the GPIO
26 * lines, by actively writing the line with 0.
27 * @dirout: MMIO address for the register to set the line as OUTPUT. It is
28 * assumed that setting a line to 1 in this register will turn that
29 * line into an output line. Conversely, setting the line to 0 will
30 * turn that line into an input.
31 * @dirin: MMIO address for the register to set this line as INPUT. It is
32 * assumed that setting a line to 1 in this register will turn that
33 * line into an input line. Conversely, setting the line to 0 will
34 * turn that line into an output.
35 * @flags: Different flags that will affect the behaviour of the device, such
36 * as endianness etc.
37 */
38struct gpio_generic_chip_config {
39 struct device *dev;
40 unsigned long sz;
41 void __iomem *dat;
42 void __iomem *set;
43 void __iomem *clr;
44 void __iomem *dirout;
45 void __iomem *dirin;
46 unsigned long flags;
47};
48
49/**
50 * struct gpio_generic_chip - Generic GPIO chip implementation.
51 * @gc: The underlying struct gpio_chip object, implementing low-level GPIO
52 * chip routines.
53 */
54struct gpio_generic_chip {
55 struct gpio_chip gc;
56};
57
58/**
59 * gpio_generic_chip_init() - Initialize a generic GPIO chip.
60 * @chip: Generic GPIO chip to set up.
61 * @cfg: Generic GPIO chip configuration.
62 *
63 * Returns 0 on success, negative error number on failure.
64 */
65static inline int
66gpio_generic_chip_init(struct gpio_generic_chip *chip,
67 const struct gpio_generic_chip_config *cfg)
68{
69 return bgpio_init(&chip->gc, cfg->dev, cfg->sz, cfg->dat, cfg->set,
70 cfg->clr, cfg->dirout, cfg->dirin, cfg->flags);
71}
72
73/**
74 * gpio_generic_chip_set() - Set the GPIO line value of the generic GPIO chip.
75 * @chip: Generic GPIO chip to use.
76 * @offset: Hardware offset of the line to set.
77 * @value: New GPIO line value.
78 *
79 * Some modules using the generic GPIO chip, need to set line values in their
80 * direction setters but they don't have access to the gpio-mmio symbols so
81 * they use the function pointer in struct gpio_chip directly. This is not
82 * optimal and can lead to crashes at run-time in some instances. This wrapper
83 * provides a safe interface for users.
84 *
85 * Returns: 0 on success, negative error number of failure.
86 */
87static inline int
88gpio_generic_chip_set(struct gpio_generic_chip *chip, unsigned int offset,
89 int value)
90{
91 if (WARN_ON(!chip->gc.set))
92 return -EOPNOTSUPP;
93
94 return chip->gc.set(&chip->gc, offset, value);
95}
96
97#define gpio_generic_chip_lock(gen_gc) \
98 raw_spin_lock(&(gen_gc)->gc.bgpio_lock)
99
100#define gpio_generic_chip_unlock(gen_gc) \
101 raw_spin_unlock(&(gen_gc)->gc.bgpio_lock)
102
103#define gpio_generic_chip_lock_irqsave(gen_gc, flags) \
104 raw_spin_lock_irqsave(&(gen_gc)->gc.bgpio_lock, flags)
105
106#define gpio_generic_chip_unlock_irqrestore(gen_gc, flags) \
107 raw_spin_unlock_irqrestore(&(gen_gc)->gc.bgpio_lock, flags)
108
109DEFINE_LOCK_GUARD_1(gpio_generic_lock,
110 struct gpio_generic_chip,
111 gpio_generic_chip_lock(_T->lock),
112 gpio_generic_chip_unlock(_T->lock))
113
114DEFINE_LOCK_GUARD_1(gpio_generic_lock_irqsave,
115 struct gpio_generic_chip,
116 gpio_generic_chip_lock_irqsave(_T->lock, _T->flags),
117 gpio_generic_chip_unlock_irqrestore(_T->lock, _T->flags),
118 unsigned long flags)
119
120#endif /* __LINUX_GPIO_GENERIC_H */