/*
 * A simple tool trys to get current switchable graphics feature status.
 *
 * zhenyu.z.wang@intel.com
 */

#include <stdio.h>
#include <stdlib.h>
#include <pciaccess.h>
#include <sys/io.h>

#define GPIO_BASE_MASK		0xffc0

#define GPIO_DGPU_SELECT	(52-32)

#define GPIO_USE_SEL_32		0x0
#define GPIO_IO_SEL_32		0x4
#define GPIO_LVL_32		0xc
#define GPIO_USE_SEL_64		0x30
#define GPIO_IO_SEL_64		0x34
#define GPIO_LVL_64		0x38

int main()
{
    struct pci_device *pdev = NULL;
    uint16_t gpio_base;
    uint8_t gpio_ctl;
    uint8_t gpio_len;
    int i;
    uint32_t use_sel2;
    uint32_t io_sel2;
    uint32_t level_sel2;

    pci_system_init();

    pdev = pci_device_find_by_slot (0, 0, 31, 0);
    if (!pdev) {
	fprintf(stderr, "Can't open LPC device.\n");
	exit(1);
    }
    pci_device_cfg_read_u16(pdev, &gpio_base, 0x48);
    /* Desktop has 64 bytes, but Mobile has 128 bytes */

    /* Check base address is not right to determine size of IO range,
       always default to 64 bytes. */
#if 0
    if (gpio_base & (1 << 6))
	gpio_len = 64;
    else
	gpio_len = 128;
#endif
    gpio_len = 64;

    gpio_base &= GPIO_BASE_MASK;

    printf("GPIO Base address: 0x%x , Length: %d bytes\n", gpio_base, gpio_len);

    pci_device_cfg_read_u8(pdev, &gpio_ctl, 0x4c);
    if ((gpio_ctl & (1 << 4)) == 0) {
	fprintf(stderr, "GPIO I/O range is disabled, try to enable it...\n");
	pci_device_cfg_write_u8(pdev, (gpio_ctl | (1 << 4)), 0x4c);
    }

    if (iopl(3) != 0) {
	fprintf(stderr, "Can't get ioperm.\n");
	exit(1);
    }

#if 0
    printf("GPIO I/O space dump:\n");
    for (i = 0; i < gpio_len; i += 4)
	printf("0x%x: 0x%08x\n", i, inl(gpio_base+i));
#endif

    use_sel2 = inl(gpio_base + GPIO_USE_SEL_64);
    if ((use_sel2 & (1 << GPIO_DGPU_SELECT)) == 0) {
	fprintf(stderr, "GPIO52 (dGPU_select) is used for native function instead of GPIO...\n");
	exit(1);
    }
    io_sel2 = inl(gpio_base + GPIO_IO_SEL_64);
    if ((io_sel2 & (1 << GPIO_DGPU_SELECT)) != 0) {
	printf("GPIO52 (dGPU_select) is _not_ programmed as output...\n");
	exit(1);
    }
    level_sel2 = inl(gpio_base + GPIO_LVL_64);
    printf("Display Mux control is from %s\n",
	    ((level_sel2 & (1 << GPIO_DGPU_SELECT)) == 0) ? "dGPU" : "iGPU");

    exit(0);
}