/*
 * dev_a, dev_b   :   device that share a link
 * link_a, link_b :   link output on device a/b (0,1,2)
 */

#if 1
int print_width(uint8_t width)
{
	switch (max_width) {
	case 0:
		print_debug("8bit");
		break;
	case 1:
		print_debug("16bit");	
		break;
	case 3:
		print_debug("32bit");
		break;
	case 4:
		print_debug("2bit");
		break;
	case 5:
		print_debug("4bit");
		break;
	case 7:
		print_debug("physically not connected");
		break;
	default:
		print_debug("unknown");
	}
}
#endif

void setup_cht_linkwidth(device_t dev_a, device_t dev_b, 
				uint8_t link_a, uint8_t link_b)
{
	uint8_t in_width, out_width, reg_a, reg_b;
	uint32_t tmp;

	reg_a = (0x20*link_a)+0x84;
	reg_b = (0x20*link_b)+0x84;

	/* get maximum link width in/out */
	in_width = ((pci_read_config32(dev_a, reg_a) >> 16) & 0x07) & \
	               ((pci_read_config32(dev_b, reg_b) >> 20) & 0x07);

	/* get maximum link width out/in */
	out_width = ((pci_read_config32(dev_a, reg_a) >> 20) & 0x07) & \
	               ((pci_read_config32(dev_b, reg_b) >> 16) & 0x07);

#if 1
	print_debug("link width ( a->b / b->a ) : ");
	print_width(in_width);
	print_debug("/");
	print_width(out_width);
	print_debug("\r\n");
#endif

	/* write link width on device a */
	tmp =  pci_read_config32(dev_a, reg_a);
	tmp &= ~( (7<<24) | (7<<28) );
	tmp |= ( (in_width<<24)|(out_width<<28) );
	pci_write_config32(dev_a, reg_a, tmp);
	
	/* write link width on device b */
	tmp =  pci_read_config32(dev_b, reg_b);
	tmp &= ~( (7<<24) | (7<<28) );
	tmp |= ( (out_width<<24)|(in_width<<28) );
	pci_write_config32(dev_b, reg_b, tmp);

}