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S3C2440A USB
USB HOST PLL需要先升频至96MHz,然后降频至HOST需要的48MHz才可以。设置UPLLCON寄存器。
./arch/arm/mach-s3c2440/mach-smdk2440.c
384 /* set UPLLCON 96MHz */385 upllcon = (386 0x38 387 | (0x02 388 | (0x01 389 writel(upllcon, S3C2410_UPLLCON);
384 /* set UPLLCON 96MHz */385 upllcon = (386 0x38 387 | (0x02 388 | (0x01 389 writel(upllcon, S3C2410_UPLLCON);
使能2个USB HOST设置MISCCR寄存器的Bit3为1即可。
h1940(基于2410CPU)的一些代码: /* Turn off suspend on both USB ports, and switch the * selectable USB port to USB device mode. */
s3c2410_modify_misccr(S3C2410_MISCCR_USBHOST | S3C2410_MISCCR_USBSUSPND0 | S3C2410_MISCCR_USBSUSPND1, 0x0);
tmp = ( 0x78 | (0x02 | (0x03 writel(tmp, S3C2410_UPLLCON);
u-boot中的使能2个HOST的代码:./cpu/arm920t/s3c24x0/usb.c: gpio->MISCCR |= 0x8; /* 1 = use pads related USB for USB host */./cpu/arm920t/s3c24x0/usb_ohci.c: gpio->MISCCR |= 0x8; /* 1 = use pads related USB for USB host */
本文来自ChinaUnix博客,如果查看原文请点:http://blog.chinaunix.net/u1/51797/showart_2070525.html |
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