转：全志A20 GPIO 总结文档

时间：2016-08-20 12:55:42 阅读：249 评论：0 收藏：0 [点我收藏+]

链接：

http://blog.csdn.net/chwenj/article/details/42190745

/*
* author: chwenj@gmail.com.
* Agreement: GPL.
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define GPIO_SET 0xAC
#define GPIO_GET 0xAB
#define DEVICE_FILE "/dev/gpio_cdev"
typedef struct {
unsigned char count; //GPIO序列
unsigned char data; //GPIO电平状态
} gpio_userspace_t;
/*main*/
int main(/* int argc, char **argv */)
{
/*open*/
int gpio_fd, ret;
gpio_fd = open(DEVICE_FILE, O_RDWR); //读写权限打开文件
if (gpio_fd < 0) {
printf("gpio device fail to open.\n");
return -1;
}
printf("%s opend.\n", DEVICE_FILE);
#if 1
/*write*/
gpio_userspace_t write_gpio;
write_gpio.count = 5; //GPIO序列号
write_gpio.data = 1; //GPIO电平值
printf("write: count = %d , data = %d.\n", write_gpio.count, write_gpio.data);
ret = write(gpio_fd, &write_gpio, sizeof(gpio_userspace_t));
if (ret < 0) {
printf("%s fail to write.\n", DEVICE_FILE);
return -1;
}
#endif
/*ioctl*/
gpio_userspace_t ioctl_gpio;
ioctl_gpio.data = 0xff; //level:0xff
ioctl_gpio.count = 5; //pin:4
ret = ioctl(gpio_fd, GPIO_SET, &ioctl_gpio);
if (ret < 0) {
printf("ioctl: ioctl fail.\n");
return -1;
}
/*read*/
gpio_userspace_t read_gpio;
ret = read(gpio_fd, &read_gpio, sizeof(gpio_userspace_t));
if (ret < 0) {
printf("read: fail to read.\n");
return -1;
}
printf("read: count = %d, data = %d.\n", read_gpio.count, read_gpio.data);
/*close*/
close(gpio_fd);
printf("%s close.\n", DEVICE_FILE);
return 0;
}

#include <linux/fs.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/cdev.h>
#include <linux/platform_device.h>
#include <linux/utsname.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <mach/sys_config.h>
#include <mach/includes.h>
#include <linux/gpio.h>
#include <linux/delay.h>
/**********************************************************/
#define GPIO_SET 0xAC
#define GPIO_GET 0xAB
/**********************************************************/
script_item_u *gpio_list = NULL;
//gpio_userspace_t 和 gpio_pdata_t 在序列上是一一对应的关系.
typedef struct {
unsigned char count; //IO序列：0，1，2，..., 19.
unsigned char data; //IO电平.
} gpio_userspace_t;
typedef struct {
struct gpio_config gpio;
char gpio_name[32];
int gpio_cnt;
} gpio_pdata_t;
typedef struct {
//debug tag for printk
#define __DEBUG_TAG__
#ifdef __DEBUG_TAG__
#define dprintk(fmt, arg...) printk(fmt, ## arg)
#else
#define dprintk(fmt, arg...)
#endif
//char device name: /dev/gpio_cdev
#define DEVICE_NAME "gpio_cdev"
//multiple
#define MUL_SEL_INPUT 0
#define MUL_SEL_OUTPUT 1
//char device
struct cdev *gpio_cdev;
dev_t devid;
struct class *gpio_class;
//gpio count
int gpio_cnt;
//general gpio subsystem
gpio_pdata_t pin[20];
//
} gpio_info_t;
static gpio_info_t info;
//global gpio pin record:
char pin_count;
/**********************************************************/
static int gpio_cdev_open(struct inode *inode, struct file *file)
{
dprintk("[gpio]: gpio_cdev_open fn.\n");
return 0;
}
static int gpio_cdev_release(struct inode *inode, struct file *file)
{
dprintk("[gpio]: gpio_cdev_release fn.\n");
return 0;
}
/**********************************************************/
//write
static ssize_t gpio_cdev_write(struct file *file, const char __user *buf, \
size_t count, loff_t *ppos)
{
gpio_userspace_t write_gpio;
unsigned char write_data, write_count;
dprintk("[gpio]: gpio_cdev_write fn.\n");
copy_from_user(&write_gpio, (gpio_userspace_t *)buf, sizeof(gpio_userspace_t));
write_data = write_gpio.data;
write_count = write_gpio.count;
dprintk("[gpio][write]: data=%d, count=%d.\n", write_data, write_count);
//error correction.
if ((write_data != 0) && (write_data != 1)) {
dprintk("[gpio][write][error]: write_data invalid.\n");
}
if ((write_count < 0) || (write_count >19)) {
dprintk("[gpio][write][error]: write_count does not exit.\n");
}
gpio_direction_output(info.pin[write_count].gpio.gpio, write_data);
//mdelay(1);
return 0;
}
//read
static ssize_t gpio_cdev_read(struct file *file, char __user *buf, \
size_t count, loff_t *ppos)
{
int i;
unsigned char data;
unsigned int gpio;
gpio_userspace_t read_gpio;
dprintk("[gpio]: gpio_cdev_read fn.\n");
#if 0
gpio_userspace_t read_gpio[20];
for (i = 0; i < 20; i++) {
gpio = info.pin[i].gpio.gpio;
//调试用；不要轻易打开：
#if 0
if(0 != gpio_direction_input(gpio)) {
dprintk("set to input failed.\n");
continue;
}
#endif
data = __gpio_get_value(gpio);
read_gpio[i].count = i;
read_gpio[i].data = data;
dprintk("[gpio][read]: pin_%d = %d.\n", read_gpio[i].count, read_gpio[i].data);
}
copy_to_user(buf, read_gpio, 20*sizeof(gpio_userspace_t));
#else
i = pin_count;
dprintk("[gpio][read]: pin_count = %d.\n", i);
gpio = info.pin[i].gpio.gpio;
data = __gpio_get_value(gpio);
read_gpio.count = i;
read_gpio.data = data;
dprintk("[gpio][read]: count = %d; data = %d.\n", read_gpio.count, read_gpio.data);
copy_to_user(buf, &read_gpio, sizeof(gpio_userspace_t));
#endif
return 0;
}
static long gpio_cdev_ioctl(struct file *file, unsigned int cmd, \
unsigned long arg)
{
dprintk("[gpio]: gpio_cdev_ioctl fn;");
dprintk(" cmd = %d.\n", cmd);
void __user *uarg;
uarg = (void __user *)arg;
gpio_userspace_t ioctl_gpio;
copy_from_user(&ioctl_gpio, (gpio_userspace_t *)uarg, sizeof(gpio_userspace_t));
dprintk("[gpio]:count = %d, data = %d.\n", ioctl_gpio.count, ioctl_gpio.data);
switch(cmd) {
case GPIO_SET:
dprintk("[gpio]: ioctl cmd = GPIO_SET.\n");
pin_count = ioctl_gpio.count;
dprintk("[gpio]: pin_count = %d.\n", pin_count);
if ((pin_count > 19)|| (pin_count < 0)) {
dprintk("[gpio][error]: gpio_cdev_ioctl: pin_count invalide.\n");
}
break;
case GPIO_GET:
dprintk("[gpio]: ioctl cmd = GPIO_SET.\n");
break;
default:
dprintk("[gpio]: ioctl cmd = default.\n");
break;
}
return 0;
}
static const struct file_operations gpio_cdev_fops = {
.owner = THIS_MODULE,
.open = gpio_cdev_open,
.release = gpio_cdev_release,
.write = gpio_cdev_write,
.read = gpio_cdev_read,
.unlocked_ioctl = gpio_cdev_ioctl,
};
static int gpio_fetch_config(void)
{
char buffer[32] = {};
int i;
int cnt = info.gpio_cnt;
script_item_value_type_e type;
script_item_u val;
dprintk("[gpio]: gpio_fetch_config fn.\n");
dprintk("[gpio]: gpio_cnt=%d.\n", cnt);
dprintk("--------------------\n");
for(i=0; i< cnt; i++) {
//format sprintf
sprintf(buffer, "gpio_pin_%d", i);
dprintk("[gpio]: buffer=%s.\n", buffer);
//fetch gpio_pin_# issue
type = script_get_item("gpio_para", buffer, &val);
if (SCIRPT_ITEM_VALUE_TYPE_PIO != type) {
dprintk("[gpio]: item value type INVALID.\n");
return -1;
}
else {
info.pin[i].gpio.gpio = val.gpio.gpio;
info.pin[i].gpio.mul_sel = val.gpio.mul_sel;
dprintk("[gpio][pin%d]: gpio=%d, mul_sel=%d, ", i, info.pin[i].gpio.gpio, info.pin[i].gpio.mul_sel);
strcpy(info.pin[i].gpio_name, buffer);
dprintk("name=%s, ", info.pin[i].gpio_name);
info.pin[i].gpio_cnt = i;
dprintk("gpio_cnt=%d.\n", info.pin[i].gpio_cnt);
dprintk("--------------------\n");
}
}
dprintk("[gpio]: success to gpio_fetch_config.\n");
return 0;
}
static int __init gpio_module_init(void)
{
int ret = 0, err;
int cnt = 0, i;
script_item_value_type_e type;
script_item_u val;
dprintk("[gpio]: gpio_module_init fn.\n");
ret = alloc_chrdev_region(&(info.devid), 0, 20, DEVICE_NAME);
if ( ret ) {
dprintk("[gpio]: fail to alloc_chrdev_region.\n");
return -1;
}
dprintk("[gpio]: devid major=%d, minor=%d.\n", MAJOR(info.devid), MINOR(info.devid));
info.gpio_cdev = cdev_alloc();
cdev_init(info.gpio_cdev, &gpio_cdev_fops);
info.gpio_cdev->owner = THIS_MODULE;
err = cdev_add(info.gpio_cdev, info.devid, 1);
if (err) {
dprintk("[gpio]: cdev_add fail.\n");
return -1;
}
info.gpio_class = class_create(THIS_MODULE, DEVICE_NAME);
if (IS_ERR(info.gpio_class)) {
dprintk("[gpio]: class_create fail.\n");
return -1;
}
device_create(info.gpio_class, NULL, info.devid, NULL, DEVICE_NAME);
dprintk("[gpio]: success to create a gpio cdev.\n");
//
type = script_get_item("gpio_para", "gpio_used", &val);
if (SCIRPT_ITEM_VALUE_TYPE_INT != type) {
dprintk("[gpio]: type not right.\n");
return -1;
}
if (!val.val) {
dprintk("[gpio]: gpio is not used.\n");
return -1;
}
dprintk("[gpio]: gpio is used.\n");
//
cnt = script_get_pio_list("gpio_para", &gpio_list);
dprintk("[gpio]: cnt = %d.\n", cnt);
info.gpio_cnt = cnt;
if (cnt == 0) {
dprintk("[gpio]: fail to script_get_pio_list.\n");
return -1;
}
else {
dprintk("[gpio]: requeset gpio(s).\n");
for (i=0; i < cnt; i++) {
dprintk("[gpio]: requeset gpio No.%d.\n", i+1);
if (0 != gpio_request(gpio_list[i].gpio.gpio, NULL))
dprintk("[gpio]: i = %d; fail to gpio_request.\n", i);
}
}
//dprintk("[gpio]: 1.\n");
//config gpio.
if (0 != sw_gpio_setall_range(&gpio_list[0], cnt)) {
dprintk("[gpio]: fail to sw_gpio_setall_range.\n");
return -1;
}
//dprintk("[gpio]: 2.\n");
/*************************************************************/
gpio_fetch_config();
//dprintk("[gpio]: 3.\n");
#if 0
//test gpio.
gpio_direction_output(info.pin[4].gpio.gpio, 0);
mdelay(5);
gpio_direction_output(info.pin[4].gpio.gpio, 1);
mdelay(5);
#endif
//dprintk("[gpio]: 4.\n");
return 0;
}
static void __exit gpio_module_exit(void)
{
dprintk("[gpio]: gpio_module_exit fn.\n");
device_destroy(info.gpio_class, info.devid);
class_destroy(info.gpio_class);
cdev_del(info.gpio_cdev);
}
module_init(gpio_module_init);
module_exit(gpio_module_exit);
MODULE_AUTHOR("chwenj@gmail.com");
MODULE_DESCRIPTION("gpio driver");
MODULE_LICENSE("GPL");

转：全志A20 GPIO 总结文档

原文：http://www.cnblogs.com/yfz0/p/5790076.html

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