Use helper functions to access flash chips

Right now we perform direct pointer manipulation without any abstraction
to read from and write to memory mapped flash chips. That makes it
impossible to drive any flasher which does not mmap the whole chip.

Using helper functions readb() and writeb() allows a driver for external
flash programmers like Paraflasher to replace readb and writeb with
calls to its own chip access routines.

This patch has the additional advantage of removing lots of unnecessary
casts to volatile uint8_t * and now-superfluous parentheses which caused
poor readability.

I used the semantic patcher Coccinelle to create this patch. The
semantic patch follows:
@@
expression a;
typedef uint8_t;
volatile uint8_t *b;
@@
- *(b) = (a);
+ writeb(a, b);
@@
volatile uint8_t *b;
@@
- *(b)
+ readb(b)
@@
type T;
T b;
@@
(
 readb
|
 writeb
)
 (...,
- (T)
- (b)
+ b
 )

In contrast to a sed script, the semantic patch performs type checking
before converting anything.

Tested-by: Joe Julian

Corresponding to flashrom svn r418 and coreboot v2 svn r3971.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: FENG Yu Ning <fengyuning1984@gmail.com>
diff --git a/sst49lfxxxc.c b/sst49lfxxxc.c
index 2c9a87b..397ee61 100644
--- a/sst49lfxxxc.c
+++ b/sst49lfxxxc.c
@@ -50,20 +50,20 @@
 	//printf("bios=0x%08lx\n", (unsigned long)bios);
 	for (i = 0; left > 65536; i++, left -= 65536) {
 		//printf("lockbits at address=0x%08lx is 0x%01x\n", (unsigned long)0xFFC00000 - size + (i * 65536) + 2, *(bios + (i * 65536) + 2) );
-		*(bios + (i * 65536) + 2) = bits;
+		writeb(bits, bios + (i * 65536) + 2);
 	}
 	address = i * 65536;
 	//printf("lockbits at address=0x%08lx is 0x%01x\n", (unsigned long)0xFFc00000 - size + address + 2, *(bios + address + 2) );
-	*(bios + address + 2) = bits;
+	writeb(bits, bios + address + 2);
 	address += 32768;
 	//printf("lockbits at address=0x%08lx is 0x%01x\n", (unsigned long)0xFFc00000 - size + address + 2, *(bios + address + 2) );
-	*(bios + address + 2) = bits;
+	writeb(bits, bios + address + 2);
 	address += 8192;
 	//printf("lockbits at address=0x%08lx is 0x%01x\n", (unsigned long)0xFFc00000 - size + address + 2, *(bios + address + 2) );
-	*(bios + address + 2) = bits;
+	writeb(bits, bios + address + 2);
 	address += 8192;
 	//printf("lockbits at address=0x%08lx is 0x%01x\n", (unsigned long)0xFFc00000 - size + address + 2, *(bios + address + 2) );
-	*(bios + address + 2) = bits;
+	writeb(bits, bios + address + 2);
 
 	return 0;
 }
@@ -73,14 +73,14 @@
 {
 	unsigned char status;
 
-	*bios = SECTOR_ERASE;
-	*(bios + address) = ERASE;
+	writeb(SECTOR_ERASE, bios);
+	writeb(ERASE, bios + address);
 
 	do {
-		status = *bios;
+		status = readb(bios);
 		if (status & (STATUS_ESS | STATUS_BPS)) {
 			printf("sector erase FAILED at address=0x%08lx status=0x%01x\n", (unsigned long)bios + address, status);
-			*bios = CLEAR_STATUS;
+			writeb(CLEAR_STATUS, bios);
 			return (-1);
 		}
 	} while (!(status & STATUS_WSMS));
@@ -96,7 +96,7 @@
 	int i;
 	unsigned char status;
 
-	*bios = CLEAR_STATUS;
+	writeb(CLEAR_STATUS, bios);
 	for (i = 0; i < page_size; i++) {
 		/* transfer data from source to destination */
 		if (*src == 0xFF) {
@@ -105,14 +105,14 @@
 			continue;
 		}
 		/*issue AUTO PROGRAM command */
-		*bios = AUTO_PGRM;
-		*dst++ = *src++;
+		writeb(AUTO_PGRM, bios);
+		writeb(*src++, dst++);
 
 		do {
-			status = *bios;
+			status = readb(bios);
 			if (status & (STATUS_ESS | STATUS_BPS)) {
 				printf("sector write FAILED at address=0x%08lx status=0x%01x\n", (unsigned long)dst, status);
-				*bios = CLEAR_STATUS;
+				writeb(CLEAR_STATUS, bios);
 				return (-1);
 			}
 		} while (!(status & STATUS_WSMS));
@@ -127,13 +127,13 @@
 
 	uint8_t id1, id2;
 
-	*bios = RESET;
+	writeb(RESET, bios);
 
-	*bios = READ_ID;
-	id1 = *(volatile uint8_t *)bios;
-	id2 = *(volatile uint8_t *)(bios + 0x01);
+	writeb(READ_ID, bios);
+	id1 = readb(bios);
+	id2 = readb(bios + 0x01);
 
-	*bios = RESET;
+	writeb(RESET, bios);
 
 	printf_debug("%s: id1 0x%02x, id2 0x%02x\n", __FUNCTION__, id1, id2);
 
@@ -157,7 +157,7 @@
 		if (erase_sector_49lfxxxc(bios, i) != 0)
 			return (-1);
 
-	*bios = RESET;
+	writeb(RESET, bios);
 
 	return 0;
 }
@@ -183,7 +183,7 @@
 	}
 	printf("\n");
 
-	*bios = RESET;
+	writeb(RESET, bios);
 
 	return 0;
 }