1 /*
2 * Basic memory-mapped GPIO controllers.
3 *
4 * Copyright 2008 MontaVista Software, Inc.
5 * Copyright 2008,2010 Anton Vorontsov <cbouatmailru@gmail.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
11 */
12
13 #ifndef __BASIC_MMIO_GPIO_H
14 #define __BASIC_MMIO_GPIO_H
15
16 #include <linux/gpio.h>
17 #include <linux/types.h>
18 #include <linux/compiler.h>
19 #include <linux/spinlock_types.h>
20
21 struct bgpio_pdata {
22 const char *label;
23 int base;
24 int ngpio;
25 };
26
27 struct device;
28
29 struct bgpio_chip {
30 struct gpio_chip gc;
31
32 unsigned long (*read_reg)(void __iomem *reg);
33 void (*write_reg)(void __iomem *reg, unsigned long data);
34
35 void __iomem *reg_dat;
36 void __iomem *reg_set;
37 void __iomem *reg_clr;
38 void __iomem *reg_dir;
39
40 /* Number of bits (GPIOs): <register width> * 8. */
41 int bits;
42
43 /*
44 * Some GPIO controllers work with the big-endian bits notation,
45 * e.g. in a 8-bits register, GPIO7 is the least significant bit.
46 */
47 unsigned long (*pin2mask)(struct bgpio_chip *bgc, unsigned int pin);
48
49 /*
50 * Used to lock bgpio_chip->data. Also, this is needed to keep
51 * shadowed and real data registers writes together.
52 */
53 spinlock_t lock;
54
55 /* Shadowed data register to clear/set bits safely. */
56 unsigned long data;
57
58 /* Shadowed direction registers to clear/set direction safely. */
59 unsigned long dir;
60 };
61
to_bgpio_chip(struct gpio_chip * gc)62 static inline struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc)
63 {
64 return container_of(gc, struct bgpio_chip, gc);
65 }
66
67 int bgpio_remove(struct bgpio_chip *bgc);
68 int bgpio_init(struct bgpio_chip *bgc, struct device *dev,
69 unsigned long sz, void __iomem *dat, void __iomem *set,
70 void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
71 unsigned long flags);
72
73 #define BGPIOF_BIG_ENDIAN BIT(0)
74 #define BGPIOF_UNREADABLE_REG_SET BIT(1) /* reg_set is unreadable */
75 #define BGPIOF_UNREADABLE_REG_DIR BIT(2) /* reg_dir is unreadable */
76 #define BGPIOF_BIG_ENDIAN_BYTE_ORDER BIT(3)
77
78 #endif /* __BASIC_MMIO_GPIO_H */
79