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, 29 insertions, 29 deletions

diff --git a/sharplhf00l04.c b/sharplhf00l04.c
index 7db14fe..06a14ef 100644
--- a/sharplhf00l04.c
+++ b/sharplhf00l04.c
@@ -41,23 +41,23 @@ int probe_lhf00l04(struct flashchip *flash)
 
 #if 0
 	/* Enter ID mode */
-	*(volatile uint8_t *)(bios + 0x5555) = 0xAA;
-	*(volatile uint8_t *)(bios + 0x2AAA) = 0x55;
-	*(volatile uint8_t *)(bios + 0x5555) = 0x90;
+	writeb(0xAA, bios + 0x5555);
+	writeb(0x55, bios + 0x2AAA);
+	writeb(0x90, bios + 0x5555);
 #endif
 
-	*bios = 0xff;
+	writeb(0xff, bios);
 	myusec_delay(10);
-	*bios = 0x90;
+	writeb(0x90, bios);
 	myusec_delay(10);
 
-	id1 = *(volatile uint8_t *)bios;
-	id2 = *(volatile uint8_t *)(bios + 0x01);
+	id1 = readb(bios);
+	id2 = readb(bios + 0x01);
 
 	/* Leave ID mode */
-	*(volatile uint8_t *)(bios + 0x5555) = 0xAA;
-	*(volatile uint8_t *)(bios + 0x2AAA) = 0x55;
-	*(volatile uint8_t *)(bios + 0x5555) = 0xF0;
+	writeb(0xAA, bios + 0x5555);
+	writeb(0x55, bios + 0x2AAA);
+	writeb(0xF0, bios + 0x5555);
 
 	myusec_delay(10);
 
@@ -76,25 +76,25 @@ uint8_t wait_lhf00l04(volatile uint8_t *bios)
 	uint8_t status;
 	uint8_t id1, id2;
 
-	*bios = 0x70;
-	if ((*bios & 0x80) == 0) {	// it's busy
-		while ((*bios & 0x80) == 0) ;
+	writeb(0x70, bios);
+	if ((readb(bios) & 0x80) == 0) {	// it's busy
+		while ((readb(bios) & 0x80) == 0) ;
 	}
 
-	status = *bios;
+	status = readb(bios);
 
 	// put another command to get out of status register mode
 
-	*bios = 0x90;
+	writeb(0x90, bios);
 	myusec_delay(10);
 
-	id1 = *(volatile uint8_t *)bios;
-	id2 = *(volatile uint8_t *)(bios + 0x01);
+	id1 = readb(bios);
+	id2 = readb(bios + 0x01);
 
 	// this is needed to jam it out of "read id" mode
-	*(volatile uint8_t *)(bios + 0x5555) = 0xAA;
-	*(volatile uint8_t *)(bios + 0x2AAA) = 0x55;
-	*(volatile uint8_t *)(bios + 0x5555) = 0xF0;
+	writeb(0xAA, bios + 0x5555);
+	writeb(0x55, bios + 0x2AAA);
+	writeb(0xF0, bios + 0x5555);
 
 	return status;
 }
@@ -106,19 +106,19 @@ int erase_lhf00l04_block(struct flashchip *flash, int offset)
 	uint8_t status;
 
 	// clear status register
-	*bios = 0x50;
+	writeb(0x50, bios);
 	printf("Erase at %p\n", bios);
 	status = wait_lhf00l04(flash->virtual_memory);
 	print_lhf00l04_status(status);
 	// clear write protect
 	printf("write protect is at %p\n", (wrprotect));
-	printf("write protect is 0x%x\n", *(wrprotect));
-	*(wrprotect) = 0;
-	printf("write protect is 0x%x\n", *(wrprotect));
+	printf("write protect is 0x%x\n", readb(wrprotect));
+	writeb(0, wrprotect);
+	printf("write protect is 0x%x\n", readb(wrprotect));
 
 	// now start it
-	*(volatile uint8_t *)(bios) = 0x20;
-	*(volatile uint8_t *)(bios) = 0xd0;
+	writeb(0x20, bios);
+	writeb(0xd0, bios);
 	myusec_delay(10);
 	// now let's see what the register is
 	status = wait_lhf00l04(flash->virtual_memory);
@@ -149,8 +149,8 @@ void write_page_lhf00l04(volatile uint8_t *bios, uint8_t *src,
 
 	for (i = 0; i < page_size; i++) {
 		/* transfer data from source to destination */
-		*dst = 0x40;
-		*dst++ = *src++;
+		writeb(0x40, dst);
+		writeb(*src++, dst++);
 		wait_lhf00l04(bios);
 	}
 }
@@ -163,7 +163,7 @@ int write_lhf00l04(struct flashchip *flash, uint8_t *buf)
 	volatile uint8_t *bios = flash->virtual_memory;
 
 	erase_lhf00l04(flash);
-	if (*bios != 0xff) {
+	if (readb(bios) != 0xff) {
 		printf("ERASE FAILED!\n");
 		return -1;
 	}