FriendlyARM mini6410 pwm0 输出驱动 对照之前的pwm驱动文章 即可读懂
2011-12-22 12:28
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#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 "pwm" #define PWM_IOCTL_SET_FREQ 1 #define PWM_IOCTL_STOP 0 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_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 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; 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("S3C6410 PWM Driver");
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