ioremap完成GPIO的输出控制。

ti

为BBB写了一个小驱动，用ioremap完成的，可以用宏定义GPIOX1_X2,，程序如下：

#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define GPIOGROUP_NUM 4
//#define GPIO1_BASE 0x4804c000
#define GPIO_OE_OFFSET 0x134
#define GPIO_DATAOUT_OFFET 0X13c
/*修改GPIO_MA(对应GPIO0~GPIO3) GPIO_MI(对应0~31)) GPIO_NUM=GPIO_MA*32+GPIO_MI*/
#define GPIO_MA 1
#define GPIO_MI 28
#define GPIO_NUM 0
#define GPIOLED_NUM 1
#define NAME_LEN 16
#define GPIOLED_MAJOR 0
#define MKGPIONUM(ma,mi) (ma * 32 + mi)
#define MAGPIO(num) (num / 32)
#define MIGPIO(num) (num % 32)
static unsigned int gpiobase[GPIOGROUP_NUM] = {0x44E07000, 0x4804C000, 0x481AC000, 0x481AE000};
static unsigned int gpio_oe,gpio_dataout;
static char gpio_ma, gpio_mi;
static int major = GPIOLED_MAJOR;
static dev_t devnum;
static struct class *gpioled_class;
struct gpioled_dev{
struct cdev cdev;
char name[NAME_LEN];
//unsigned int gpio_num;
char gpio_ma;
char gpio_mi;
struct device *gpioled_device;
};
static struct gpioled_dev *gpioled_devp;
static int gpioled_open(struct inode *inode, struct file *filp)
{
int ret = 0;
unsigned int value_tmp;
filp->private_data = container_of(inode->i_cdev, struct gpioled_dev, cdev);
struct gpioled_dev *devp = filp->private_data;
value_tmp = readl(gpio_dataout);
printk("gpioled open and gpio%d_outdata:0x%lx.n",MKGPIONUM(devp->gpio_ma, devp->gpio_mi),(unsigned long)value_tmp);
return ret;
}
static ssize_t gpioled_read(struct file *filp,char __user *buf,size_t count,loff_t *ppos)
{
unsigned int value_tmp;
struct gpioled_dev *devp = filp->private_data;
value_tmp = readl(gpio_dataout);
if(copy_to_user(buf,&value_tmp,sizeof(value_tmp)))
printk(KERN_INFO "read failed!n");
else
{
*ppos+=sizeof(value_tmp);
printk(KERN_INFO "%s open and outdata:0x%lx.n",devp->name, (unsigned long)value_tmp);
}
return 0;
}
static ssize_t gpioled_write (struct file *filp, const char __user *buf, size_t count, loff_t *ppos)
{
char value;
struct gpioled_dev *devp = filp->private_data;
copy_from_user(&value, buf, sizeof(value));
if(value == '1')
writel((1<gpio_mi),gpio_dataout);
else if(value == '0')
writel((0<gpio_mi),gpio_dataout);
else
printk("no valid value value:%d.n",value);
return sizeof(value);
}
static int gpioled_release(struct inode *inode, struct file *filp)
{
int ret = 0;
return ret;
}
static struct file_operations gpioled_fops = {
.owner = THIS_MODULE,
.open = gpioled_open,
.read = gpioled_read,
.write = gpioled_write,
.release = gpioled_release,
};
static void gpioled_setup(struct gpioled_dev * devp, int index)
{
int ret = 0;
devnum = MKDEV(major,index);
cdev_init(&devp->cdev,&gpioled_fops);
devp->cdev.owner = THIS_MODULE;
ret = cdev_add(&devp->cdev,devnum,1);
if(ret)
{
printk(KERN_INFO "Error %d adding gpioled%d.n",ret, index);
}
else
{
devp->gpio_ma = gpio_ma;
devp->gpio_mi = gpio_mi;
sprintf(devp->name,"gpio%d_%d",devp->gpio_ma, devp->gpio_mi);
devp->gpioled_device = device_create(gpioled_class, NULL, devnum,NULL,devp->name);
printk(KERN_INFO "%s init.n",devp->name);
}
}
static int __init gpioled_init(void)
{
int i, ret = 0;
unsigned int value_tmp;
if(GPIO_NUM != 0)
{
gpio_ma = MAGPIO(GPIO_NUM);
gpio_mi = MIGPIO(GPIO_NUM);
}
else
{
gpio_ma = GPIO_MA;
gpio_mi = GPIO_MI;
}
if(request_mem_region(gpiobase[gpio_ma] | GPIO_OE_OFFSET,sizeof(int),"GPIO_OE"))
{
ret = -EBUSY;
goto fail;
}
if(request_mem_region(gpiobase[gpio_ma] | GPIO_DATAOUT_OFFET,sizeof(int),"GPIO_DATAOUT"))
{
ret = -EBUSY;
goto fail;
}
gpio_oe = ioremap(gpiobase[gpio_ma] | GPIO_OE_OFFSET,sizeof(int));
if(gpio_oe == NULL)
{
release_mem_region(gpiobase[gpio_ma] | GPIO_OE_OFFSET,sizeof(int));
ret = -ENOMEM;
goto fail;
}
gpio_dataout = ioremap(gpiobase[gpio_ma] | GPIO_DATAOUT_OFFET,sizeof(int));
if(gpio_dataout == NULL)
{
release_mem_region(gpiobase[gpio_ma] | GPIO_DATAOUT_OFFET,sizeof(int));
ret = -ENOMEM;
goto fail;
}
if(major)
{
devnum = MKDEV(major,0);
ret = register_chrdev_region(devnum,GPIOLED_NUM,"gpioled");
}
else
{
ret = alloc_chrdev_region(&devnum,0,GPIOLED_NUM,"gpioled");
major = MAJOR(devnum);
}
if(ret < 0)
{
goto fail;
}
gpioled_devp = kzalloc(sizeof(struct gpioled_dev) * GPIOLED_NUM,GFP_KERNEL);
if(IS_ERR(gpioled_devp))
{
ret = -ENOMEM;
goto fail;
}
gpioled_class = class_create(THIS_MODULE,"gpioled");
for(i=0; i
{
gpioled_setup(gpioled_devp + i, i);
}
writel(~(1<
fail:
return ret;
}
static void __exit gpioled_exit(void)
{
int i;
for(i=0; i
{
devnum = MKDEV(major,i);
device_destroy(gpioled_class,devnum);
printk("%s exit.n",(gpioled_devp+ i)->name);
cdev_del(&(gpioled_devp+i)->cdev);
unregister_chrdev_region(devnum,1);
}
class_destroy(gpioled_class);
kfree(gpioled_devp);
}
module_init(gpioled_init);
module_exit(gpioled_exit);
MODULE_AUTHOR("yang yongsheng");
MODULE_LICENSE("GPL v2");