为何使用PWM0没有波形输出?
头文件中没有关于寄存器TCON,TCNTB,TCMPB,TCFG1,TCFG0的虚拟地址的映射,
是跟S3C2410_VA_TIMER一致吗?
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;
tcon = __raw_readl(S3C2410_TCON);
tcfg1 = __raw_readl(S3C2410_TCFG1);
tcfg0 = __raw_readl(S3C2410_TCFG0);
//prescaler = 50
tcfg0 &= ~255;
tcfg0 |= (50 - 1);
//mux = 1/16
tcfg1 &= ~15;
tcfg1 |= 4;
__raw_writel(tcfg1, S3C2410_TCFG1);
__raw_writel(tcfg0, S3C2410_TCFG0);
clk_p = clk_get(NULL, "pclk");
pclk = clk_get_rate(clk_p);
tcnt = (pclk/50/16)/freq;
printk("PCLK = %lu, tcnt = %lu\n", pclk, tcnt);
__raw_writel(tcnt, S3C2410_TCNTB(0));
__raw_writel(tcnt/2, 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);
}
[ 此帖被xililena在2013-04-10 19:14重新编辑 ]