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 <linux/spinlock.h> 18 19#include <asm-generic/gpio.h> 20 21#include <mach/irqs.h> 22#include <mach/common.h> 23 24#define DAVINCI_GPIO_BASE 0x01C67000 25 26enum davinci_gpio_type { 27 GPIO_TYPE_DAVINCI = 0, 28 GPIO_TYPE_TNETV107X, 29}; 30 31#define GPIO(X) (X) /* 0 <= X <= (DAVINCI_N_GPIO - 1) */ 32 33/* Convert GPIO signal to GPIO pin number */ 34#define GPIO_TO_PIN(bank, gpio) (16 * (bank) + (gpio)) 35 36struct davinci_gpio_controller { 37 struct gpio_chip chip; 38 int irq_base; 39 spinlock_t lock; 40 void __iomem *regs; 41 void __iomem *set_data; 42 void __iomem *clr_data; 43 void __iomem *in_data; 44}; 45 46/* The __gpio_to_controller() and __gpio_mask() functions inline to constants 47 * with constant parameters; or in outlined code they execute at runtime. 48 * 49 * You'd access the controller directly when reading or writing more than 50 * one gpio value at a time, and to support wired logic where the value 51 * being driven by the cpu need not match the value read back. 52 * 53 * These are NOT part of the cross-platform GPIO interface 54 */ 55static inline struct davinci_gpio_controller * 56__gpio_to_controller(unsigned gpio) 57{ 58 struct davinci_gpio_controller *ctlrs = davinci_soc_info.gpio_ctlrs; 59 int index = gpio / 32; 60 61 if (!ctlrs || index >= davinci_soc_info.gpio_ctlrs_num) 62 return NULL; 63 64 return ctlrs + index; 65} 66 67static inline u32 __gpio_mask(unsigned gpio) 68{ 69 return 1 << (gpio % 32); 70} 71 72/* 73 * The get/set/clear functions will inline when called with constant 74 * parameters referencing built-in GPIOs, for low-overhead bitbanging. 75 * 76 * gpio_set_value() will inline only on traditional Davinci style controllers 77 * with distinct set/clear registers. 78 * 79 * Otherwise, calls with variable parameters or referencing external 80 * GPIOs (e.g. on GPIO expander chips) use outlined functions. 81 */ 82static inline void gpio_set_value(unsigned gpio, int value) 83{ 84 if (__builtin_constant_p(value) && gpio < davinci_soc_info.gpio_num) { 85 struct davinci_gpio_controller *ctlr; 86 u32 mask; 87 88 ctlr = __gpio_to_controller(gpio); 89 90 if (ctlr->set_data != ctlr->clr_data) { 91 mask = __gpio_mask(gpio); 92 if (value) 93 __raw_writel(mask, ctlr->set_data); 94 else 95 __raw_writel(mask, ctlr->clr_data); 96 return; 97 } 98 } 99 100 __gpio_set_value(gpio, value); 101} 102 103/* Returns zero or nonzero; works for gpios configured as inputs OR 104 * as outputs, at least for built-in GPIOs. 105 * 106 * NOTE: for built-in GPIOs, changes in reported values are synchronized 107 * to the GPIO clock. This is easily seen after calling gpio_set_value() 108 * and then immediately gpio_get_value(), where the gpio_get_value() will 109 * return the old value until the GPIO clock ticks and the new value gets 110 * latched. 111 */ 112static inline int gpio_get_value(unsigned gpio) 113{ 114 struct davinci_gpio_controller *ctlr; 115 116 if (!__builtin_constant_p(gpio) || gpio >= davinci_soc_info.gpio_num) 117 return __gpio_get_value(gpio); 118 119 ctlr = __gpio_to_controller(gpio); 120 return __gpio_mask(gpio) & __raw_readl(ctlr->in_data); 121} 122 123static inline int gpio_cansleep(unsigned gpio) 124{ 125 if (__builtin_constant_p(gpio) && gpio < davinci_soc_info.gpio_num) 126 return 0; 127 else 128 return __gpio_cansleep(gpio); 129} 130 131static inline int gpio_to_irq(unsigned gpio) 132{ 133 return __gpio_to_irq(gpio); 134} 135 136static inline int irq_to_gpio(unsigned irq) 137{ 138 /* don't support the reverse mapping */ 139 return -ENOSYS; 140} 141 142#endif /* __DAVINCI_GPIO_H */ 143