video: bochs: Avoid using IO instructions to access VGA IO port
At present the driver uses IO instructions to access the legacy
VGA IO ports, which unfortunately limits the driver to work only
on x86. It turns out the IO instruction is not necessary as Bochs
VGA card remaps the legacy VGA IO ports (0x3c0 -> 0x3df) to its
memory mapped register space from offset 0x400.
Update the driver to use MMIO access for VGA IO port.
Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org> # qemu-x86_64
diff --git a/drivers/video/bochs.c b/drivers/video/bochs.c
index 2d4526c..5923ff8 100644
--- a/drivers/video/bochs.c
+++ b/drivers/video/bochs.c
@@ -27,9 +27,9 @@
return readw(mmio + MMIO_BASE + index * 2);
}
-static void bochs_vga_write(uint8_t val)
+static void bochs_vga_write(void *mmio, int index, uint8_t val)
{
- outb(val, VGA_ATT_W);
+ writeb(val, mmio + VGA_BASE + index);
}
static int bochs_init_fb(struct udevice *dev)
@@ -79,7 +79,7 @@
bochs_write(mmio, INDEX_ENABLE, ENABLED | LFB_ENABLED);
/* disable blanking */
- bochs_vga_write(VGA_AR_ENABLE_DISPLAY);
+ bochs_vga_write(mmio, VGA_ATT_W - VGA_INDEX, VGA_AR_ENABLE_DISPLAY);
plat->base = fb;
diff --git a/drivers/video/bochs.h b/drivers/video/bochs.h
index 71d3d60..3facf69 100644
--- a/drivers/video/bochs.h
+++ b/drivers/video/bochs.h
@@ -11,9 +11,6 @@
#define VGA_ATT_W 0x3c0
#define VGA_AR_ENABLE_DISPLAY 0x20
-#define IOPORT_INDEX 0x01ce
-#define IOPORT_DATA 0x01cf
-
enum {
INDEX_ID,
INDEX_XRES,
@@ -34,6 +31,7 @@
#define LFB_ENABLED BIT(6)
#define NOCLEARMEM BIT(7)
+#define VGA_BASE 0x400
#define MMIO_BASE 0x500
#endif