作者:指间流年 | 来源:互联网 | 2017-08-07 04:54
首先这是我第一次开发linux,请各位勿喷哈,,,最近用友善之臂mini2440,更改原板内设备驱动(其实就是简单的两个置位操作,我就是照着原来的模仿的)后调用总是出错(调用ioct中的turn_dir报错bad address),红字字体是我写的,请教各位强人,,,先谢了,
#include
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#define DEVICE_NAME "pwm"
#define PWM_IOCTL_SET_FREQ 1
#define PWM_IOCTL_STOP 0
#define PWM_IOCTL_TURN 2
static struct semaphore lock;
/* freq: pclk/50/16/65536 ~ pclk/50/16
* if pclk = 50MHz, freq is 1Hz to 62500Hz
* human ear : 20Hz~ 20000Hz
*/
static void PWM_TURN(unsigned long dir)
{
if (dir==1)
{
s3c2410_gpio_cfgpin(S3C2410_GPF(2), S3C2410_GPIO_OUTPUT);
s3c2410_gpio_setpin(S3C2410_GPF(2), 1);
s3c2410_gpio_cfgpin(S3C2410_GPF(3), S3C2410_GPIO_OUTPUT);
s3c2410_gpio_setpin(S3C2410_GPF(3), 1);
}
if(dir==2)
{
s3c2410_gpio_cfgpin(S3C2410_GPF(2), S3C2410_GPIO_OUTPUT);
s3c2410_gpio_setpin(S3C2410_GPF(2), 1);
s3c2410_gpio_cfgpin(S3C2410_GPF(3), S3C2410_GPIO_OUTPUT);
s3c2410_gpio_setpin(S3C2410_GPF(3), 0);
}
}static void PWM_Set_Freq( unsigned long freq )
{
unsigned long tcon;
unsigned long tcnt;
unsigned long tcfg1;
unsigned long tcfg0;
struct clk *clk_p;
unsigned long pclk;
//set GPB0 as tout0, pwm output
s3c2410_gpio_cfgpin(S3C2410_GPB(0), S3C2410_GPB0_TOUT0);
tcon = __raw_readl(S3C2410_TCON);
tcfg1 = __raw_readl(S3C2410_TCFG1);
tcfg0 = __raw_readl(S3C2410_TCFG0);
//prescaler = 50
tcfg0 &= ~S3C2410_TCFG_PRESCALER0_MASK;
tcfg0 |= (50 - 1);
//mux = 1/16
tcfg1 &= ~S3C2410_TCFG1_MUX0_MASK;
tcfg1 |= S3C2410_TCFG1_MUX0_DIV16;
__raw_writel(tcfg1, S3C2410_TCFG1);
__raw_writel(tcfg0, S3C2410_TCFG0);
clk_p = clk_get(NULL, "pclk");
pclk = clk_get_rate(clk_p);
/*****************************************************************
将pwm的频率固定为1000Hz
*****************************************************************/
tcnt = (pclk/50/16)/1000;
__raw_writel(tcnt, S3C2410_TCNTB(0));
/*****************************************************************
freq的意义变为pwm波的占空比,通过本函数参数来改变占空比
*****************************************************************/
__raw_writel(tcnt*10/freq, S3C2410_TCMPB(0));
tcon &= ~0x1f;
tcon |= 0xb; //disable deadzone, auto-reload, inv-off, update TCNTB0&TCMPB0, start timer 0
__raw_writel(tcon, S3C2410_TCON);
tcon &= ~2; //clear manual update bit
__raw_writel(tcon, S3C2410_TCON);
}
static void PWM_Stop(void)
{
s3c2410_gpio_cfgpin(S3C2410_GPB(0), S3C2410_GPIO_OUTPUT);
s3c2410_gpio_setpin(S3C2410_GPB(0), 0);
}
static int s3c24xx_pwm_open(struct inode *inode, struct file *file)
{
s3c2410_gpio_cfgpin(S3C2410_GPF(0), S3C2410_GPIO_OUTPUT);
s3c2410_gpio_setpin(S3C2410_GPF(0), 1);
if (!down_trylock(&lock))
return 0;
else
return -EBUSY;
}
static int s3c24xx_pwm_close(struct inode *inode, struct file *file)
{
PWM_Stop();
up(&lock);
return 0;
}
static int s3c24xx_pwm_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
//printk("ioctl pwm: %x %lx\n", cmd, arg);
switch (cmd) {
case PWM_IOCTL_SET_FREQ:
if (arg == 0)
return -EINVAL;
PWM_Set_Freq(arg);
break;
case PWM_IOCTL_STOP:
PWM_Stop();
break;
case PWM_IOCTL_TURN:
PWM_TURN(arg);
break;
} return 0;
}
static struct file_operations dev_fops = {
.owner = THIS_MODULE,
.open = s3c24xx_pwm_open,
.release = s3c24xx_pwm_close,
.ioctl = s3c24xx_pwm_ioctl,
};
static struct miscdevice misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DEVICE_NAME,
.fops = &dev_fops,
};
static int __init dev_init(void)
{
int ret;
init_MUTEX(&lock);
ret = misc_register(&misc);
printk (DEVICE_NAME"\tinitialized\n");
return ret;
}
static void __exit dev_exit(void)
{
misc_deregister(&misc);
}
module_init(dev_init);
module_exit(dev_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("FriendlyARM Inc.");
MODULE_DESCRIPTION("S3C2410/S3C2440 PWM Driver");