[PATCH] FILO: Kconfig option for forcing NAND flash mode

[Nathan Williams]

This patch adds support for enabling NAND flash even if it hasn't
been set up by coreboot.  Since DIVIL_LBAR_FLSH[x], NANDF_DATA
and NANDF_CTL are likely to be incorrect, they can be specified
in Kconfig as well.

Signed-off-by: Nathan Williams

Index: Config.in
===================================================================
--- Config.in	(revision 143)
+++ Config.in	(working copy)
@@ -141,6 +141,46 @@
    help
      Driver for Geode NAND flash storage

+config FORCE_NAND_FLASH
+	bool "Enable NAND flash automatically"
+	default n
+	depends on FLASH_DISK
+	help
+	  If Geode is currently set to IDE mode, change
+	  to NAND flash mode.
+
+config DIVIL_LBAR_FLSH_HI
+	hex "LBAR_FLSH[x] (hi)"
+	default "0xfffff007"
+	depends on FORCE_NAND_FLASH
+	help
+	  Local BAR Flash Chip Select.  See AMD Geode CS5536 Companion
+	  Device Data Book section 6.6.2.8 for details.
+
+config DIVIL_LBAR_FLSH_LO
+	hex "LBAR_FLSH[x] (lo)"
+	default "0x20000000"
+	depends on FORCE_NAND_FLASH
+	help
+	  Local BAR Flash Chip Select.  See AMD Geode CS5536 Companion
+	  Device Data Book section 6.6.2.8 for details.
+
+config NANDF_DATA
+	hex "Initial NANDF_DATA"
+	default "0x00100010"
+	depends on FORCE_NAND_FLASH
+	help
+	  Specify NAND Flash Data Timing MSR value.  See AMD Geode
+	  CS5536 Companion Device Data Book section 6.19.1.3 for details.
+
+config NANDF_CTL
+	hex "Initial NANDF_CTL"
+	default "0x00000010"
+	depends on FORCE_NAND_FLASH
+	help
+	  Specify NAND Flash Control Timing MSR value.  See AMD Geode
+	  CS5536 Companion Device Data Book section 6.19.1.4 for details.
+
 config SUPPORT_PCI
    bool "PCI support"
    default y
Index: drivers/flash/lxflash.c
===================================================================
--- drivers/flash/lxflash.c	(revision 143)
+++ drivers/flash/lxflash.c	(working copy)
@@ -523,8 +523,21 @@

int NAND_close(void)
 {
-	if (g_chipID >= 0)
+	if (g_chipID >= 0) {
    	wrmsr(MSR_DIVIL_LBAR_FLSH0 + g_chipID, g_orig_flsh);
+#ifdef CONFIG_FORCE_NAND_FLASH
+		// Set up NAND data and control timing for OS
+		msr_t tmp;
+
+		tmp = rdmsr(MSR_NANDF_DATA);
+		tmp.lo = CONFIG_NANDF_DATA;
+		wrmsr(MSR_NANDF_DATA, tmp);
+
+		tmp = rdmsr(MSR_NANDF_CTL);
+		tmp.lo = CONFIG_NANDF_CTL;
+		wrmsr(MSR_NANDF_CTL, tmp);
+#endif
+	}
 }

////////////////////////////////////////////////////////////////////////////////
@@ -547,19 +560,31 @@
    msr = rdmsr(MSR_DIVIL_BALL_OPTS);
    
    if (msr.lo & PIN_OPT_IDE) {
+#ifndef CONFIG_FORCE_NAND_FLASH	
    	printf("NAND controller not enabled!\n");
    	return -1;
+#else
+		printf("Enabling NAND controller\n");
+		msr.lo &= ~PIN_OPT_IDE;
+		wrmsr(MSR_DIVIL_BALL_OPTS, msr);
+#endif
    }
    
    ///////////////////////////////////////////////////////////////////////////////////
    // init the MSR_DIVIL_LBAR_FLSHx register, I/O mapped mode, set a hardcoded base address
    // Later we restore initial state
    
+#ifdef CONFIG_FORCE_NAND_FLASH
+	// When we NAND_close() restore to these values instead
+	g_orig_flsh.hi = CONFIG_DIVIL_LBAR_FLSH_HI;
+	g_orig_flsh.lo = CONFIG_DIVIL_LBAR_FLSH_LO;
+#else	
    g_orig_flsh = rdmsr(MSR_DIVIL_LBAR_FLSH0 + chipNum);
    if (!(g_orig_flsh.hi & NOR_NAND)) {
    	printf("CS%d set up for NOR, aborting!\n", chipNum);
    	return -1;
    }
+#endif
    
    msr.hi = SET_FLSH_HIGH;
    msr.lo = SET_FLSH_LOW;