Autodetect presence of serial flash and set up the board accordingly.
This enables us to have only one configuration and one set of code for
all revisions of the Gigabyte GA-M57SLI-S4.
Flash is now setup correctly for both SPI and LPC flash.

Detection of SPI flash in flashrom on rev. 2.x boards now hangs
instead of failing. However, that is just an effect of the combination
of incomplete initialization of the SPI controller and paranoid checks
in the flashrom SPI code.
If anyone wants to work on that, he needs a logic analyzer or creative
imagination. Hint: LPC-to-SPI read passthrough, clock signal.

Remaining issues for the M57SLI: Fan/environment control.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Harald Gutmann <harald.gutmann@gmx.net>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2972 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
diff --git a/src/mainboard/gigabyte/m57sli/cache_as_ram_auto.c b/src/mainboard/gigabyte/m57sli/cache_as_ram_auto.c
index 3a17ef2..30e2e69 100644
--- a/src/mainboard/gigabyte/m57sli/cache_as_ram_auto.c
+++ b/src/mainboard/gigabyte/m57sli/cache_as_ram_auto.c
@@ -93,6 +93,7 @@
 #include "northbridge/amd/amdk8/setup_resource_map.c"
 
 #define SERIAL_DEV PNP_DEV(0x2e, IT8716F_SP1)
+#define GPIO_DEV PNP_DEV(0x2e, IT8716F_GPIO)
 
 #include "southbridge/nvidia/mcp55/mcp55_early_ctrl.c"
 
@@ -265,13 +266,27 @@
 
         int needs_reset = 0;
         unsigned bsp_apicid = 0;
+	uint8_t tmp = 0;
 
         if (bist == 0) {
 		bsp_apicid = init_cpus(cpu_init_detectedx, sysinfo);
         }
 
 	pnp_enter_ext_func_mode(SERIAL_DEV);
-        pnp_write_config(SERIAL_DEV, 0x23, 1);
+	/* The following line will set CLKIN to 24 MHz */
+	pnp_write_config(SERIAL_DEV, IT8716F_CONFIG_REG_CLOCKSEL, 1);
+	tmp = pnp_read_config(SERIAL_DEV, IT8716F_CONFIG_REG_SWSUSP);
+	/* Is serial flash enabled? Then enable writing to serial flash. */
+	if (tmp & 0x0e) {
+		pnp_write_config(SERIAL_DEV, IT8716F_CONFIG_REG_SWSUSP, tmp | 0x10);
+		pnp_set_logical_device(GPIO_DEV);
+		/* Set Serial Flash interface to 0x0820 */
+		pnp_write_config(GPIO_DEV, 0x64, 0x08);
+		pnp_write_config(GPIO_DEV, 0x65, 0x20);
+		/* We can get away with not resetting the logical device because
+		 * it8716f_enable_dev(SERIAL_DEV, TTYS0_BASE) will do that.
+		 */
+	}
  	it8716f_enable_dev(SERIAL_DEV, TTYS0_BASE);
 	pnp_exit_ext_func_mode(SERIAL_DEV);