mini6410 PWM驱动程序

mini6410 PWM驱动程序:#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 <plat/gpio-cfg.h>
#include <plat/regs-clock.h>
#include <plat/regs-gpio.h>#include <plat/gpio-bank-e.h>
#include <plat/gpio-bank-f.h>
#include <plat/gpio-bank-k.h>#define DEVICE_NAME     "pwm"#define PWM_IOCTL_SET_FREQ 1
#define PWM_IOCTL_STOP   0static 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_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 &= ~（0x3U << 28）;
tmp |= （0x2U << 28）;
writel（tmp, S3C64XX_GPFCON）; 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）; //mux = 1/16
tcfg1 &= ~S3C_TCFG1_MUX0_MASK;
tcfg1 |= S3C_TCFG1_MUX0_DIV16; __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））;
__raw_writel（tcnt/2, S3C_TCMPB（0））;

tcon &= ~0x1f;
tcon |= 0xb; //disable deadzone, auto-reload, inv-off, update TCNTB0&TCMPB0, start timer 0
__raw_writel（tcon, S3C_TCON）;

tcon &= ~2;   //clear manual update bit
__raw_writel（tcon, S3C_TCON）;
}void PWM_Stop（ void ）
{
unsigned tmp;
tmp = readl（S3C64XX_GPFCON）;
tmp &= ~（0x3U << 28）;
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 int s3c64xx_pwm_ioctl（struct inode *inode, struct file *file, 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,
    .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; init_MUTEX（&lock）;
ret = misc_register（&misc）; printk （DEVICE_NAME" initialized "）;
     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（"S3C6410 PWM Driver"）;