diff options
Diffstat (limited to 'arch/blackfin/mach-bf548/gpio.c')
| -rw-r--r-- | arch/blackfin/mach-bf548/gpio.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/arch/blackfin/mach-bf548/gpio.c b/arch/blackfin/mach-bf548/gpio.c new file mode 100644 index 000000000000..854896d6ceda --- /dev/null +++ b/arch/blackfin/mach-bf548/gpio.c @@ -0,0 +1,175 @@ +/* + * File: arch/blackfin/mach-bf548/gpio.c + * Based on: + * Author: Michael Hennerich (hennerich@blackfin.uclinux.org) + * + * Created: + * Description: GPIO Abstraction Layer + * + * Modified: + * Copyright 2007 Analog Devices Inc. + * + * Bugs: Enter bugs at http://blackfin.uclinux.org/ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see the file COPYING, or write + * to the Free Software Foundation, Inc., + * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <linux/module.h> +#include <linux/err.h> +#include <asm/blackfin.h> +#include <asm/gpio.h> +#include <linux/irq.h> + +static struct gpio_port_t *gpio_array[gpio_bank(MAX_BLACKFIN_GPIOS)] = { + (struct gpio_port_t *) PORTA_FER, + (struct gpio_port_t *) PORTB_FER, + (struct gpio_port_t *) PORTC_FER, + (struct gpio_port_t *) PORTD_FER, + (struct gpio_port_t *) PORTE_FER, + (struct gpio_port_t *) PORTF_FER, + (struct gpio_port_t *) PORTG_FER, + (struct gpio_port_t *) PORTH_FER, + (struct gpio_port_t *) PORTI_FER, + (struct gpio_port_t *) PORTJ_FER, +}; + +static unsigned short reserved_map[gpio_bank(MAX_BLACKFIN_GPIOS)]; + +inline int check_gpio(unsigned short gpio) +{ + if (gpio == GPIO_PB15 || gpio == GPIO_PC14 || gpio == GPIO_PC15 \ + || gpio == GPIO_PH14 || gpio == GPIO_PH15 \ + || gpio > MAX_BLACKFIN_GPIOS) + return -EINVAL; + return 0; +} + +static void port_setup(unsigned short gpio, unsigned short usage) +{ + if (usage == GPIO_USAGE) { + if (gpio_array[gpio_bank(gpio)]->port_fer & gpio_bit(gpio)) + printk(KERN_WARNING "bfin-gpio: Possible Conflict with Peripheral " + "usage and GPIO %d detected!\n", gpio); + gpio_array[gpio_bank(gpio)]->port_fer &= ~gpio_bit(gpio); + } else + gpio_array[gpio_bank(gpio)]->port_fer |= gpio_bit(gpio); + SSYNC(); +} + +static int __init bfin_gpio_init(void) +{ + int i; + + printk(KERN_INFO "Blackfin GPIO Controller\n"); + + for (i = 0; i < MAX_BLACKFIN_GPIOS; i+=GPIO_BANKSIZE) + reserved_map[gpio_bank(i)] = 0; + + return 0; +} + +arch_initcall(bfin_gpio_init); + + +/*********************************************************** +* +* FUNCTIONS: Blackfin GPIO Driver +* +* INPUTS/OUTPUTS: +* gpio - GPIO Number between 0 and MAX_BLACKFIN_GPIOS +* +* +* DESCRIPTION: Blackfin GPIO Driver API +* +* CAUTION: +************************************************************* +* MODIFICATION HISTORY : +**************************************************************/ + +int gpio_request(unsigned short gpio, const char *label) +{ + unsigned long flags; + + if (check_gpio(gpio) < 0) + return -EINVAL; + + local_irq_save(flags); + + if (unlikely(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio))) { + printk(KERN_ERR "bfin-gpio: GPIO %d is already reserved!\n", gpio); + dump_stack(); + local_irq_restore(flags); + return -EBUSY; + } + reserved_map[gpio_bank(gpio)] |= gpio_bit(gpio); + + local_irq_restore(flags); + + port_setup(gpio, GPIO_USAGE); + + return 0; +} +EXPORT_SYMBOL(gpio_request); + + +void gpio_free(unsigned short gpio) +{ + unsigned long flags; + + if (check_gpio(gpio) < 0) + return; + + local_irq_save(flags); + + if (unlikely(!(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio)))) { + printk(KERN_ERR "bfin-gpio: GPIO %d wasn't reserved!\n", gpio); + dump_stack(); + local_irq_restore(flags); + return; + } + + reserved_map[gpio_bank(gpio)] &= ~gpio_bit(gpio); + + local_irq_restore(flags); +} +EXPORT_SYMBOL(gpio_free); + + +void gpio_direction_input(unsigned short gpio) +{ + unsigned long flags; + + BUG_ON(!(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio))); + + local_irq_save(flags); + gpio_array[gpio_bank(gpio)]->port_dir_clear = gpio_bit(gpio); + gpio_array[gpio_bank(gpio)]->port_inen |= gpio_bit(gpio); + local_irq_restore(flags); +} +EXPORT_SYMBOL(gpio_direction_input); + +void gpio_direction_output(unsigned short gpio) +{ + unsigned long flags; + + BUG_ON(!(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio))); + + local_irq_save(flags); + gpio_array[gpio_bank(gpio)]->port_inen &= ~gpio_bit(gpio); + gpio_array[gpio_bank(gpio)]->port_dir_set = gpio_bit(gpio); + local_irq_restore(flags); +} +EXPORT_SYMBOL(gpio_direction_output); |