Add generic 16 bit and 32 bit chip read/write emulation to the external flasher infrastructure

The emulation works by splitting 32 bit accesses into 16 bit accesses
and 16 bit accesses into to 8 bit accesses. That way, external flashers
can mix and match the amount of emulation they need.

Corresponding to flashrom svn r517.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>
diff --git a/flash.h b/flash.h
index 11e14c6..a51458e 100644
--- a/flash.h
+++ b/flash.h
@@ -611,6 +611,10 @@
 uint8_t internal_chip_readb(const volatile void *addr);
 uint16_t internal_chip_readw(const volatile void *addr);
 uint32_t internal_chip_readl(const volatile void *addr);
+void fallback_chip_writew(uint16_t val, volatile void *addr);
+void fallback_chip_writel(uint32_t val, volatile void *addr);
+uint16_t fallback_chip_readw(const volatile void *addr);
+uint32_t fallback_chip_readl(const volatile void *addr);
 #if defined(__FreeBSD__) || defined(__DragonFly__)
 extern int io_fd;
 #endif
@@ -635,11 +639,7 @@
 void *nic3com_map(const char *descr, unsigned long phys_addr, size_t len);
 void nic3com_unmap(void *virt_addr, size_t len);
 void nic3com_chip_writeb(uint8_t val, volatile void *addr);
-void nic3com_chip_writew(uint16_t val, volatile void *addr);
-void nic3com_chip_writel(uint32_t val, volatile void *addr);
 uint8_t nic3com_chip_readb(const volatile void *addr);
-uint16_t nic3com_chip_readw(const volatile void *addr);
-uint32_t nic3com_chip_readl(const volatile void *addr);
 extern struct pcidev_status nics_3com[];
 
 /* flashrom.c */
diff --git a/flashrom.c b/flashrom.c
index e00e678..5c5967a 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -69,11 +69,11 @@
 		.map_flash_region	= nic3com_map,
 		.unmap_flash_region	= nic3com_unmap,
 		.chip_readb		= nic3com_chip_readb,
-		.chip_readw		= nic3com_chip_readw,
-		.chip_readl		= nic3com_chip_readl,
+		.chip_readw		= fallback_chip_readw,
+		.chip_readl		= fallback_chip_readl,
 		.chip_writeb		= nic3com_chip_writeb,
-		.chip_writew		= nic3com_chip_writew,
-		.chip_writel		= nic3com_chip_writel,
+		.chip_writew		= fallback_chip_writew,
+		.chip_writel		= fallback_chip_writel,
 	},
 
 	{},
diff --git a/internal.c b/internal.c
index bbbf58b..f10d0d5 100644
--- a/internal.c
+++ b/internal.c
@@ -168,3 +168,34 @@
 	return *(volatile uint32_t *) addr;
 }
 
+/* Little-endian fallback for drivers not supporting 16 bit accesses */
+void fallback_chip_writew(uint16_t val, volatile void *addr)
+{
+	chip_writeb(val & 0xff, addr);
+	chip_writeb((val >> 8) & 0xff, addr + 1);
+}
+
+/* Little-endian fallback for drivers not supporting 16 bit accesses */
+uint16_t fallback_chip_readw(const volatile void *addr)
+{
+	uint16_t val;
+	val = chip_readb(addr);
+	val |= chip_readb(addr + 1) << 8;
+	return val;
+}
+
+/* Little-endian fallback for drivers not supporting 32 bit accesses */
+void fallback_chip_writel(uint32_t val, volatile void *addr)
+{
+	chip_writew(val & 0xffff, addr);
+	chip_writew((val >> 16) & 0xffff, addr + 2);
+}
+
+/* Little-endian fallback for drivers not supporting 32 bit accesses */
+uint32_t fallback_chip_readl(const volatile void *addr)
+{
+	uint32_t val;
+	val = chip_readw(addr);
+	val |= chip_readw(addr + 2) << 16;
+	return val;
+}
diff --git a/nic3com.c b/nic3com.c
index a4b680a..84e506d 100644
--- a/nic3com.c
+++ b/nic3com.c
@@ -93,14 +93,6 @@
 	OUTB(val, io_base_addr + BIOS_ROM_DATA);
 }
 
-void nic3com_chip_writew(uint16_t val, volatile void *addr)
-{
-}
-
-void nic3com_chip_writel(uint32_t val, volatile void *addr)
-{
-}
-
 uint8_t nic3com_chip_readb(const volatile void *addr)
 {
 	uint8_t val;
@@ -110,13 +102,3 @@
 
 	return val;
 }
-
-uint16_t nic3com_chip_readw(const volatile void *addr)
-{
-	return 0xffff;
-}
-
-uint32_t nic3com_chip_readl(const volatile void *addr)
-{
-	return 0xffffffff;
-}