1 /*
2 * TI DaVinci GPIO Support
3 *
4 * Copyright (c) 2006 David Brownell
5 * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13 #ifndef __DAVINCI_GPIO_H
14 #define __DAVINCI_GPIO_H
15
16 #include <linux/io.h>
17 #include <asm-generic/gpio.h>
18
19 #include <mach/irqs.h>
20 #include <mach/common.h>
21
22 #define DAVINCI_GPIO_BASE 0x01C67000
23
24 /*
25 * basic gpio routines
26 *
27 * board-specific init should be done by arch/.../.../board-XXX.c (maybe
28 * initializing banks together) rather than boot loaders; kexec() won't
29 * go through boot loaders.
30 *
31 * the gpio clock will be turned on when gpios are used, and you may also
32 * need to pay attention to PINMUX registers to be sure those pins are
33 * used as gpios, not with other peripherals.
34 *
35 * On-chip GPIOs are numbered 0..(DAVINCI_N_GPIO-1). For documentation,
36 * and maybe for later updates, code may write GPIO(N). These may be
37 * all 1.8V signals, all 3.3V ones, or a mix of the two. A given chip
38 * may not support all the GPIOs in that range.
39 *
40 * GPIOs can also be on external chips, numbered after the ones built-in
41 * to the DaVinci chip. For now, they won't be usable as IRQ sources.
42 */
43 #define GPIO(X) (X) /* 0 <= X <= (DAVINCI_N_GPIO - 1) */
44
45 struct gpio_controller {
46 u32 dir;
47 u32 out_data;
48 u32 set_data;
49 u32 clr_data;
50 u32 in_data;
51 u32 set_rising;
52 u32 clr_rising;
53 u32 set_falling;
54 u32 clr_falling;
55 u32 intstat;
56 };
57
58 /* The __gpio_to_controller() and __gpio_mask() functions inline to constants
59 * with constant parameters; or in outlined code they execute at runtime.
60 *
61 * You'd access the controller directly when reading or writing more than
62 * one gpio value at a time, and to support wired logic where the value
63 * being driven by the cpu need not match the value read back.
64 *
65 * These are NOT part of the cross-platform GPIO interface
66 */
67 static inline struct gpio_controller *__iomem
68 __gpio_to_controller(unsigned gpio)
69 {
70 void *__iomem ptr;
71 void __iomem *base = davinci_soc_info.gpio_base;
72
73 if (gpio < 32 * 1)
74 ptr = base + 0x10;
75 else if (gpio < 32 * 2)
76 ptr = base + 0x38;
77 else if (gpio < 32 * 3)
78 ptr = base + 0x60;
79 else if (gpio < 32 * 4)
80 ptr = base + 0x88;
81 else
82 ptr = NULL;
83 return ptr;
84 }
85
86 static inline u32 __gpio_mask(unsigned gpio)
87 {
88 return 1 << (gpio % 32);
89 }
90
91 /* The get/set/clear functions will inline when called with constant
92 * parameters referencing built-in GPIOs, for low-overhead bitbanging.
93 *
94 * Otherwise, calls with variable parameters or referencing external
95 * GPIOs (e.g. on GPIO expander chips) use outlined functions.
96 */
97 static inline void gpio_set_value(unsigned gpio, int value)
98 {
99 if (__builtin_constant_p(value) && gpio < DAVINCI_N_GPIO) {
100 struct gpio_controller *__iomem g;
101 u32 mask;
102
103 g = __gpio_to_controller(gpio);
104 mask = __gpio_mask(gpio);
105 if (value)
106 __raw_writel(mask, &g->set_data);
107 else
108 __raw_writel(mask, &g->clr_data);
109 return;
110 }
111
112 __gpio_set_value(gpio, value);
113 }
114
115 /* Returns zero or nonzero; works for gpios configured as inputs OR
116 * as outputs, at least for built-in GPIOs.
117 *
118 * NOTE: for built-in GPIOs, changes in reported values are synchronized
119 * to the GPIO clock. This is easily seen after calling gpio_set_value()
120 * and then immediately gpio_get_value(), where the gpio_get_value() will
121 * return the old value until the GPIO clock ticks and the new value gets
122 * latched.
123 */
124 static inline int gpio_get_value(unsigned gpio)
125 {
126 struct gpio_controller *__iomem g;
127
128 if (!__builtin_constant_p(gpio) || gpio >= DAVINCI_N_GPIO)
129 return __gpio_get_value(gpio);
130
131 g = __gpio_to_controller(gpio);
132 return __gpio_mask(gpio) & __raw_readl(&g->in_data);
133 }
134
135 static inline int gpio_cansleep(unsigned gpio)
136 {
137 if (__builtin_constant_p(gpio) && gpio < DAVINCI_N_GPIO)
138 return 0;
139 else
140 return __gpio_cansleep(gpio);
141 }
142
143 static inline int gpio_to_irq(unsigned gpio)
144 {
145 if (gpio >= DAVINCI_N_GPIO)
146 return -EINVAL;
147 return davinci_soc_info.intc_irq_num + gpio;
148 }
149
150 static inline int irq_to_gpio(unsigned irq)
151 {
152 /* caller guarantees gpio_to_irq() succeeded */
153 return irq - davinci_soc_info.intc_irq_num;
154 }
155
156 #endif /* __DAVINCI_GPIO_H */
157
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