2 * TI DaVinci GPIO Support
4 * Copyright (c) 2006 David Brownell
5 * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com>
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.
13 #ifndef __DAVINCI_GPIO_H
14 #define __DAVINCI_GPIO_H
17 #include <linux/spinlock.h>
19 #include <asm-generic/gpio.h>
21 #include <mach/irqs.h>
22 #include <mach/common.h>
24 #define DAVINCI_GPIO_BASE 0x01C67000
26 enum davinci_gpio_type {
27 GPIO_TYPE_DAVINCI = 0,
33 * board-specific init should be done by arch/.../.../board-XXX.c (maybe
34 * initializing banks together) rather than boot loaders; kexec() won't
35 * go through boot loaders.
37 * the gpio clock will be turned on when gpios are used, and you may also
38 * need to pay attention to PINMUX registers to be sure those pins are
39 * used as gpios, not with other peripherals.
41 * On-chip GPIOs are numbered 0..(DAVINCI_N_GPIO-1). For documentation,
42 * and maybe for later updates, code may write GPIO(N). These may be
43 * all 1.8V signals, all 3.3V ones, or a mix of the two. A given chip
44 * may not support all the GPIOs in that range.
46 * GPIOs can also be on external chips, numbered after the ones built-in
47 * to the DaVinci chip. For now, they won't be usable as IRQ sources.
49 #define GPIO(X) (X) /* 0 <= X <= (DAVINCI_N_GPIO - 1) */
51 /* Convert GPIO signal to GPIO pin number */
52 #define GPIO_TO_PIN(bank, gpio) (16 * (bank) + (gpio))
54 struct davinci_gpio_controller {
55 struct gpio_chip chip;
59 void __iomem *set_data;
60 void __iomem *clr_data;
61 void __iomem *in_data;
64 /* The __gpio_to_controller() and __gpio_mask() functions inline to constants
65 * with constant parameters; or in outlined code they execute at runtime.
67 * You'd access the controller directly when reading or writing more than
68 * one gpio value at a time, and to support wired logic where the value
69 * being driven by the cpu need not match the value read back.
71 * These are NOT part of the cross-platform GPIO interface
73 static inline struct davinci_gpio_controller *
74 __gpio_to_controller(unsigned gpio)
76 struct davinci_gpio_controller *ctlrs = davinci_soc_info.gpio_ctlrs;
77 int index = gpio / 32;
79 if (!ctlrs || index >= davinci_soc_info.gpio_ctlrs_num)
85 static inline u32 __gpio_mask(unsigned gpio)
87 return 1 << (gpio % 32);
90 /* The get/set/clear functions will inline when called with constant
91 * parameters referencing built-in GPIOs, for low-overhead bitbanging.
93 * Otherwise, calls with variable parameters or referencing external
94 * GPIOs (e.g. on GPIO expander chips) use outlined functions.
96 static inline void gpio_set_value(unsigned gpio, int value)
98 if (__builtin_constant_p(value) && gpio < davinci_soc_info.gpio_num) {
99 struct davinci_gpio_controller *ctlr;
102 ctlr = __gpio_to_controller(gpio);
103 mask = __gpio_mask(gpio);
105 __raw_writel(mask, ctlr->set_data);
107 __raw_writel(mask, ctlr->clr_data);
111 __gpio_set_value(gpio, value);
114 /* Returns zero or nonzero; works for gpios configured as inputs OR
115 * as outputs, at least for built-in GPIOs.
117 * NOTE: for built-in GPIOs, changes in reported values are synchronized
118 * to the GPIO clock. This is easily seen after calling gpio_set_value()
119 * and then immediately gpio_get_value(), where the gpio_get_value() will
120 * return the old value until the GPIO clock ticks and the new value gets
123 static inline int gpio_get_value(unsigned gpio)
125 struct davinci_gpio_controller *ctlr;
127 if (!__builtin_constant_p(gpio) || gpio >= davinci_soc_info.gpio_num)
128 return __gpio_get_value(gpio);
130 ctlr = __gpio_to_controller(gpio);
131 return __gpio_mask(gpio) & __raw_readl(ctlr->in_data);
134 static inline int gpio_cansleep(unsigned gpio)
136 if (__builtin_constant_p(gpio) && gpio < davinci_soc_info.gpio_num)
139 return __gpio_cansleep(gpio);
142 static inline int gpio_to_irq(unsigned gpio)
144 return __gpio_to_irq(gpio);
147 static inline int irq_to_gpio(unsigned irq)
149 /* don't support the reverse mapping */
153 #endif /* __DAVINCI_GPIO_H */