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>

1 files changed, 28 insertions, 28 deletions

diff --git a/m29f400bt.c b/m29f400bt.c
index d0b040d..2ca72e4 100644
--- a/m29f400bt.c
+++ b/m29f400bt.c
@@ -22,9 +22,9 @@
 
 void protect_m29f400bt(volatile uint8_t *bios)
 {
-	*(volatile uint8_t *)(bios + 0xAAA) = 0xAA;
-	*(volatile uint8_t *)(bios + 0x555) = 0x55;
-	*(volatile uint8_t *)(bios + 0xAAA) = 0xA0;
+	writeb(0xAA, bios + 0xAAA);
+	writeb(0x55, bios + 0x555);
+	writeb(0xA0, bios + 0xAAA);
 
 	usleep(200);
 }
@@ -35,18 +35,18 @@ void write_page_m29f400bt(volatile uint8_t *bios, uint8_t *src,
 	int i;
 
 	for (i = 0; i < page_size; i++) {
-		*(volatile uint8_t *)(bios + 0xAAA) = 0xAA;
-		*(volatile uint8_t *)(bios + 0x555) = 0x55;
-		*(volatile uint8_t *)(bios + 0xAAA) = 0xA0;
+		writeb(0xAA, bios + 0xAAA);
+		writeb(0x55, bios + 0x555);
+		writeb(0xA0, bios + 0xAAA);
 
 		/* transfer data from source to destination */
-		*dst = *src;
+		writeb(*src, dst);
 		//*(volatile char *) (bios) = 0xF0;
 		//usleep(5);
 		toggle_ready_jedec(dst);
 		printf
 		    ("Value in the flash at address %p = %#x, want %#x\n",
-		     (uint8_t *) (dst - bios), *dst, *src);
+		     (uint8_t *) (dst - bios), readb(dst), *src);
 		dst++;
 		src++;
 	}
@@ -57,21 +57,21 @@ int probe_m29f400bt(struct flashchip *flash)
 	volatile uint8_t *bios = flash->virtual_memory;
 	uint8_t id1, id2;
 
-	*(volatile uint8_t *)(bios + 0xAAA) = 0xAA;
-	*(volatile uint8_t *)(bios + 0x555) = 0x55;
-	*(volatile uint8_t *)(bios + 0xAAA) = 0x90;
+	writeb(0xAA, bios + 0xAAA);
+	writeb(0x55, bios + 0x555);
+	writeb(0x90, bios + 0xAAA);
 
 	myusec_delay(10);
 
-	id1 = *(volatile uint8_t *)bios;
+	id1 = readb(bios);
 	/* The data sheet says id2 is at (bios + 0x01) and id2 listed in
 	 * flash.h does not match. It should be possible to use JEDEC probe.
 	 */
-	id2 = *(volatile uint8_t *)(bios + 0x02);
+	id2 = readb(bios + 0x02);
 
-	*(volatile uint8_t *)(bios + 0xAAA) = 0xAA;
-	*(volatile uint8_t *)(bios + 0x555) = 0x55;
-	*(volatile uint8_t *)(bios + 0xAAA) = 0xF0;
+	writeb(0xAA, bios + 0xAAA);
+	writeb(0x55, bios + 0x555);
+	writeb(0xF0, bios + 0xAAA);
 
 	myusec_delay(10);
 
@@ -87,13 +87,13 @@ int erase_m29f400bt(struct flashchip *flash)
 {
 	volatile uint8_t *bios = flash->virtual_memory;
 
-	*(volatile uint8_t *)(bios + 0xAAA) = 0xAA;
-	*(volatile uint8_t *)(bios + 0x555) = 0x55;
-	*(volatile uint8_t *)(bios + 0xAAA) = 0x80;
+	writeb(0xAA, bios + 0xAAA);
+	writeb(0x55, bios + 0x555);
+	writeb(0x80, bios + 0xAAA);
 
-	*(volatile uint8_t *)(bios + 0xAAA) = 0xAA;
-	*(volatile uint8_t *)(bios + 0x555) = 0x55;
-	*(volatile uint8_t *)(bios + 0xAAA) = 0x10;
+	writeb(0xAA, bios + 0xAAA);
+	writeb(0x55, bios + 0x555);
+	writeb(0x10, bios + 0xAAA);
 
 	myusec_delay(10);
 	toggle_ready_jedec(bios);
@@ -104,14 +104,14 @@ int erase_m29f400bt(struct flashchip *flash)
 int block_erase_m29f400bt(volatile uint8_t *bios, volatile uint8_t *dst)
 {
 
-	*(volatile uint8_t *)(bios + 0xAAA) = 0xAA;
-	*(volatile uint8_t *)(bios + 0x555) = 0x55;
-	*(volatile uint8_t *)(bios + 0xAAA) = 0x80;
+	writeb(0xAA, bios + 0xAAA);
+	writeb(0x55, bios + 0x555);
+	writeb(0x80, bios + 0xAAA);
 
-	*(volatile uint8_t *)(bios + 0xAAA) = 0xAA;
-	*(volatile uint8_t *)(bios + 0x555) = 0x55;
+	writeb(0xAA, bios + 0xAAA);
+	writeb(0x55, bios + 0x555);
 	//*(volatile uint8_t *) (bios + 0xAAA) = 0x10;
-	*dst = 0x30;
+	writeb(0x30, dst);
 
 	myusec_delay(10);
 	toggle_ready_jedec(bios);