IMX6S LINUX3.0.35 PWM驱动问题

zhanghong · 发表于 2016-11-30 17:21:52

使用LINUX3.0.35的内核，并配置了内核PWM的支持，自己写了PWM1~4路的驱动程序并编译成了驱动模块（模块初始化时就会输出波形），通过手动方式加载到开发板中，但从各引脚上测量不到有波形输出。
求一个可行的参考案例。

这个是我当前的驱动代码：
#include <linux/init.h>
#include <linux/module.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <asm/gpio.h>
#include <linux/pwm.h>
#include <linux/clk.h>

#define PWM1_ON    0x00010001
#define PWM1_OFF 0x00010002
#define PWM1_DUTY 0x00010003
#define PWM2_ON    0x00020001
#define PWM2_OFF 0x00020002
#define PWM2_DUTY 0x00020003
#define PWM3_ON    0x00030001
#define PWM3_OFF 0x00030002
#define PWM3_DUTY 0x00030003
#define PWM4_ON    0x00040001
#define PWM4_OFF 0x00040002
#define PWM4_DUTY 0x00040003
#define PWM_PERIOD 0x00050000

unsigned int nPWMPeriod=10000000; //PWM周期

struct pwm_device *pwm_dev_1=NULL;
struct pwm_device *pwm_dev_2=NULL;
struct pwm_device *pwm_dev_3=NULL;
struct pwm_device *pwm_dev_4=NULL;

static long pwm_ioctl(struct file *file, unsigned int cmd, unsigned long arg);

static struct file_operations pwm_fops =
{
.owner = THIS_MODULE,
.unlocked_ioctl = pwm_ioctl
};

static struct miscdevice pwm_misc =
{
.minor = MISC_DYNAMIC_MINOR,
.name = "mypwm",          //dev/mypwm
.fops = &pwm_fops
};

static long pwm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int ret=-1;

switch (cmd)
{
case PWM1_ON:
arg =  (arg>2000000 ? 2000000 : arg);
ret = pwm_config(pwm_dev_1, arg, nPWMPeriod);
if(ret < 0)
{
printk("pwm_dev_1 ioctl fail\r\n");
return ret;
}
pwm_enable(pwm_dev_1);

break;
case PWM1_OFF:
ret = pwm_config(pwm_dev_1, 0, nPWMPeriod);
if(ret < 0)
{
printk("pwm_dev_1 ioctl fail\r\n");
return ret;
}
pwm_disable(pwm_dev_1);

break;
case PWM1_DUTY:
arg =  (arg>2000000 ? 2000000 : arg);
ret = pwm_config(pwm_dev_1, arg, nPWMPeriod);
if(ret < ret)
{
printk("pwm_dev_1 ioctl config err\r\n");
return 0;
}

break;
case PWM2_ON:
arg =  (arg>2000000 ? 2000000 : arg);
ret = pwm_config(pwm_dev_2, arg, nPWMPeriod);
if(ret < 0)
{
printk("pwm_dev_2 ioctl fail\r\n");
return ret;
}
pwm_enable(pwm_dev_2);

break;
case PWM2_OFF:
ret = pwm_config(pwm_dev_2, 0, nPWMPeriod);
if(ret < 0)
{
printk("pwm_dev_2 ioctl fail\r\n");
return ret;
}
pwm_disable(pwm_dev_2);

break;
case PWM2_DUTY:
arg =  (arg>2000000 ? 2000000 : arg);
ret = pwm_config(pwm_dev_2, arg, nPWMPeriod);
if(ret < 0)
{
printk("pwm_dev_2 ioctl config err\r\n");
return ret;
}

break;
case PWM3_ON:
arg =  (arg>2000000 ? 2000000 : arg);
ret = pwm_config(pwm_dev_3, arg, nPWMPeriod);
if(ret < 0)
{
printk("pwm_dev_3 ioctl fail\r\n");
return ret;
}
pwm_enable(pwm_dev_3);

break;
case PWM3_OFF:
ret = pwm_config(pwm_dev_3, 0, nPWMPeriod);
if(ret < 0)
{
printk("pwm_dev_3 ioctl fail\r\n");
return ret;
}
pwm_disable(pwm_dev_3);

break;
case PWM3_DUTY:
arg =  (arg>2000000 ? 2000000 : arg);
ret = pwm_config(pwm_dev_3, arg, nPWMPeriod);
if(ret < 0)
{
printk("pwm_dev_3 ioctl config err\r\n");
return ret;
}

break;
#if 1
case PWM4_ON:
arg =  (arg>2000000 ? 2000000 : arg);
ret = pwm_config(pwm_dev_4, arg, nPWMPeriod);
if(ret < 0)
{
printk("pwm_dev_4 ioctl fail\r\n");
return ret;
}
pwm_enable(pwm_dev_4);

break;
case PWM4_OFF:
ret = pwm_config(pwm_dev_4, 0, nPWMPeriod);
if(ret < 0)
{
printk("pwm_dev_4 ioctl fail\r\n");
return ret;
}
pwm_disable(pwm_dev_4);

break;
case PWM4_DUTY:
arg =  (arg>2000000 ? 2000000 : arg);
ret = pwm_config(pwm_dev_4, arg, nPWMPeriod);
if(ret < 0)
{
printk("pwm_dev_4 ioctl config err\r\n");
return ret;
}

break;
case PWM_PERIOD:
arg =  (arg<2200000 ? 2200000 : arg);
nPWMPeriod = (unsigned int)arg;

break;
#endif
default:
return ret;
}

return ret;
}

static int pwm_init(void)
{
int ret=-1;

printk("regisger pwm_misc device\r\n");
pwm_dev_1 = pwm_request(0, "pwm_1");
if(pwm_dev_1==ERR_PTR(-EBUSY) || pwm_dev_1==ERR_PTR(-ENOENT))
{
      printk("pwm_dev_1 register fail\r\n");
return (int)pwm_dev_1;
}

pwm_dev_2 = pwm_request(1, "pwm_2");
if(pwm_dev_2==ERR_PTR(-EBUSY) || pwm_dev_2==ERR_PTR(-ENOENT))
{
printk("pwn_dev_2 register fail\r\n");
return (int)pwm_dev_2;
}

pwm_dev_3 = pwm_request(2, "pwm_3");
if(pwm_dev_3==ERR_PTR(-EBUSY) || pwm_dev_3==ERR_PTR(-ENOENT))
{
printk("pwn_dev_3 register fail\r\n");
return (int)pwm_dev_3;
}

pwm_dev_4 = pwm_request(3, "pwm_4");
if(pwm_dev_4==ERR_PTR(-EBUSY) || pwm_dev_4==ERR_PTR(-ENOENT))
{
printk("pwn_dev_4 register fail\r\n");
return 0;
}

printk("pwconfig\r\n");
ret = pwm_config(pwm_dev_1, 1000000, nPWMPeriod);
if(ret < 0)
{
printk("pwm_config_1 init fail\r\n");
return ret;
}
printk("pwconfig1\r\n");

ret = pwm_config(pwm_dev_2, 1000000, nPWMPeriod);
if(ret < 0)
{
printk("pwm_config_2 init fail\r\n");
return ret;
}
printk("pwconfig2\r\n");

ret = pwm_config(pwm_dev_3, 1000000, nPWMPeriod);
if(ret < 0)
{
printk("pwm_config_3 init fail\r\n");
return ret;
}
printk("pwconfig3\r\n");

ret = pwm_config(pwm_dev_4, 1000000, nPWMPeriod);
if(ret < 0)
{
printk("pwm_config_4 init fail\r\n");
return ret;
}
printk("pwconfig4\r\n");

ret = pwm_enable(pwm_dev_1);
if(ret == 0)
{
printk("pwm_enable_dev_1 init success\r\n");
}
else if(ret < 0 )
{
printk("pwm_enable_dev_1 init fail\r\n");
return ret;
}

ret = pwm_enable(pwm_dev_2);
if(ret == 0)
{
printk("pwm_enable_dev_2 init success\r\n");
}
else if(ret < 0 )
{
printk("pwm_enable_dev_2 init fail\r\n");
return ret;
}

ret = pwm_enable(pwm_dev_3);
if(ret == 0)
{
printk("pwm_enable_dev_3 init success\r\n");
}
else if(ret < 0 )
{
printk("pwm_enable_dev_3 init fail\r\n");
return ret;
}

ret = pwm_enable(pwm_dev_4);
if(ret == 0)
{
printk("pwm_enable_dev_4 init success\r\n");
}
else if(ret < 0 )
{
printk("pwm_enable_dev_4 init fail\r\n");
return ret;
}

ret = misc_register(&pwm_misc);

return ret;
}

static void pwm_exit(void)
{
printk("unregister pwm_misc device\r\n");
misc_deregister(&pwm_misc);

pwm_config(pwm_dev_1,0,10000000);
pwm_disable(pwm_dev_1);
pwm_free(pwm_dev_1);

pwm_config(pwm_dev_2,0,10000000);
pwm_disable(pwm_dev_2);
pwm_free(pwm_dev_2);

pwm_config(pwm_dev_3,0,10000000);
pwm_disable(pwm_dev_3);
pwm_free(pwm_dev_3);

pwm_config(pwm_dev_4,0,10000000);
pwm_disable(pwm_dev_4);
pwm_free(pwm_dev_4);
}

module_init(pwm_init);
module_exit(pwm_exit);
MODULE_LICENSE("GPL");

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