- 论坛徽章:
- 0
|
请教大家一个PWM驱动的问题，我要用6410的PWM0，PWM1驱动自动导引小车，驱动根据蜂鸣器驱动mini6410_pwm.c改的，PWM0有输出频率可以调，PWM1设置和PWM0一样，但却一直输出高电平。请大侠指教。驱动代码贴出，只修改了static void PWM_Set_Freq( unsigned long freq )。
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/poll.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <mach/hardware.h>
#include <plat/regs-timer.h>
#include <mach/regs-irq.h>
#include <asm/mach/time.h>
#include <linux/clk.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/miscdevice.h>
#include <mach/map.h>
#include <mach/regs-clock.h>
#include <mach/regs-gpio.h>
#include <plat/gpio-cfg.h>
#include <mach/gpio-bank-e.h>
#include <mach/gpio-bank-f.h>
#include <mach/gpio-bank-k.h>
#define DEVICE_NAME "gpio_pwm"
#define PWM_IOCTL_SET_FREQ 1
#define PWM_IOCTL_STOP 0
static struct semaphore lock;
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;
unsigned tmp;
tmp = readl(S3C64XX_GPFCON);
tmp &= ~(0xfU << 2 ;
tmp |= (0xaU << 2; /////////////////GPF14.GPF15设置为输出。
writel(tmp, S3C64XX_GPFCON);
printk("tmp = %x\n",tmp);
tcon = __raw_readl(S3C_TCON);
tcfg1 = __raw_readl(S3C_TCFG1);
tcfg0 = __raw_readl(S3C_TCFG0);
//prescaler = 50
tcfg0 &= ~S3C_TCFG_PRESCALER0_MASK;
tcfg0 |= (50 - 1); 预分频timer0.1公用，所以不用额外设置。
//mux = 1/16
tcfg1 &= ~(S3C_TCFG1_MUX0_MASK | S3C_TCFG1_MUX1_MASK);
tcfg1 |= S3C_TCFG1_MUX0_DIV16 | S3C_TCFG1_MUX1_DIV16; //timer1设置为16分频
__raw_writel(tcfg1, S3C_TCFG1);
__raw_writel(tcfg0, S3C_TCFG0);
clk_p = clk_get(NULL, "pclk" ;
pclk = clk_get_rate(clk_p);
tcnt = (pclk/50/16)/freq;
__raw_writel(tcnt, S3C_TCNTB(0)); //TOUT0
__raw_writel(tcnt/2, S3C_TCMPB(0));
__raw_writel(tcnt, S3C_TCNTB(1)); //TOUT1 设置和TOUT0一样，两个PWM输出一样的波形。
__raw_writel(tcnt/2, S3C_TCMPB(1));
tcon &= ~0xfff;
tcon |= 0xb0b; //PWM0，PWM1 disable deadzone, auto-reload, inv-off, update TCNTB0&TCMPB0, start timer 0
__raw_writel(tcon, S3C_TCON);
tcon &= ~(0x202); //clear manual update bit
__raw_writel(tcon, S3C_TCON);
////////////////////////////
tmp=S3C_TCNTO(0);
printk("S3C_TCNTO(0)=%d\n",S3C_TCNTO(0)); //查看TCNT0、1中的值
tmp=S3C_TCNTO(1);
printk("S3C_TCNTO(1)=%d\n",S3C_TCNTO(1));
/////////////
}
void PWM_Stop( void )
{
unsigned tmp;
tmp = readl(S3C64XX_GPFCON);
tmp &= ~(0xfU << 2;
writel(tmp, S3C64XX_GPFCON);
}
static int s3c64xx_pwm_open(struct inode *inode, struct file *file)
{
if (!down_trylock(&lock))
return 0;
else
return -EBUSY;
}
static int s3c64xx_pwm_close(struct inode *inode, struct file *file)
{
up(&lock);
return 0;
}
static long s3c64xx_pwm_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case PWM_IOCTL_SET_FREQ:
if (arg == 0)
return -EINVAL;
PWM_Set_Freq(arg);
break;
case PWM_IOCTL_STOP:
default:
PWM_Stop();
break;
}
return 0;
}
static struct file_operations dev_fops = {
.owner = THIS_MODULE,
.open = s3c64xx_pwm_open,
.release = s3c64xx_pwm_close,
.unlocked_ioctl = s3c64xx_pwm_ioctl,
};
static struct miscdevice misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DEVICE_NAME,
.fops = &dev_fops,
};
static int __init dev_init(void)
{
int ret;
sema_init(&lock, 1);
ret = misc_register(&misc);
printk (DEVICE_NAME"\t for ARM11 initialized\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("";
MODULE_DESCRIPTION("AGV PWM Driver";
请各位大侠帮忙看看哪里的问题？ |
|
免费注册
发表于 2013-07-15 11:16