linux-imx

/*

 * GPIO driver for the WinSystems WS16C48

 * Copyright (C) 2016 William Breathitt Gray

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License, version 2, as

 * published by the Free Software Foundation.

 *

 * 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.

 */

#include <linux/bitmap.h>

#include <linux/bitops.h>

#include <linux/device.h>

#include <linux/errno.h>

#include <linux/gpio/driver.h>

#include <linux/io.h>

#include <linux/ioport.h>

#include <linux/interrupt.h>

#include <linux/irqdesc.h>

#include <linux/isa.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/spinlock.h>

​

#define WS16C48_EXTENT 16

#define MAX_NUM_WS16C48 max_num_isa_dev(WS16C48_EXTENT)

​

static unsigned int base[MAX_NUM_WS16C48];

static unsigned int num_ws16c48;

module_param_hw_array(base, uint, ioport, &num_ws16c48, 0);

MODULE_PARM_DESC(base, "WinSystems WS16C48 base addresses");

​

static unsigned int irq[MAX_NUM_WS16C48];

module_param_hw_array(irq, uint, irq, NULL, 0);

MODULE_PARM_DESC(irq, "WinSystems WS16C48 interrupt line numbers");

​

/**

 * struct ws16c48_gpio - GPIO device private data structure

 * @chip:   instance of the gpio_chip

 * @io_state:   bit I/O state (whether bit is set to input or output)

 * @out_state:  output bits state

 * @lock:   synchronization lock to prevent I/O race conditions

 * @irq_mask:   I/O bits affected by interrupts

 * @flow_mask:  IRQ flow type mask for the respective I/O bits

 * @base:   base port address of the GPIO device

 */

struct ws16c48_gpio {

    struct gpio_chip chip;

    unsigned char io_state[6];

    unsigned char out_state[6];

    raw_spinlock_t lock;

    unsigned long irq_mask;

    unsigned long flow_mask;

    unsigned base;

};

​

static int ws16c48_gpio_get_direction(struct gpio_chip *chip, unsigned offset)

{

    struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip);