1 /* 2 * Copyright (C) 2012 Vikram Narayananan 3 * <vikram186@gmail.com> 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 */ 7 8 #include <common.h> 9 #include <asm/gpio.h> 10 #include <asm/io.h> 11 12 inline int gpio_is_valid(unsigned gpio) 13 { 14 return (gpio < BCM2835_GPIO_COUNT); 15 } 16 17 int gpio_request(unsigned gpio, const char *label) 18 { 19 return !gpio_is_valid(gpio); 20 } 21 22 int gpio_free(unsigned gpio) 23 { 24 return 0; 25 } 26 27 int gpio_direction_input(unsigned gpio) 28 { 29 struct bcm2835_gpio_regs *reg = 30 (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; 31 unsigned val; 32 33 val = readl(®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); 34 val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio)); 35 val |= (BCM2835_GPIO_INPUT << BCM2835_GPIO_FSEL_SHIFT(gpio)); 36 writel(val, ®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); 37 38 return 0; 39 } 40 41 int gpio_direction_output(unsigned gpio, int value) 42 { 43 struct bcm2835_gpio_regs *reg = 44 (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; 45 unsigned val; 46 47 gpio_set_value(gpio, value); 48 49 val = readl(®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); 50 val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio)); 51 val |= (BCM2835_GPIO_OUTPUT << BCM2835_GPIO_FSEL_SHIFT(gpio)); 52 writel(val, ®->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]); 53 54 return 0; 55 } 56 57 int gpio_get_value(unsigned gpio) 58 { 59 struct bcm2835_gpio_regs *reg = 60 (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; 61 unsigned val; 62 63 val = readl(®->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]); 64 65 return (val >> BCM2835_GPIO_COMMON_SHIFT(gpio)) & 0x1; 66 } 67 68 int gpio_set_value(unsigned gpio, int value) 69 { 70 struct bcm2835_gpio_regs *reg = 71 (struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE; 72 u32 *output_reg = value ? reg->gpset : reg->gpclr; 73 74 writel(1 << BCM2835_GPIO_COMMON_SHIFT(gpio), 75 &output_reg[BCM2835_GPIO_COMMON_BANK(gpio)]); 76 77 return 0; 78 } 79