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authorMiika Pekkarinen <miipekk@ihme.org>2006-11-26 14:40:47 +0000
committerMiika Pekkarinen <miipekk@ihme.org>2006-11-26 14:40:47 +0000
commitf14f59f9f387964687fda05b3881a090fb7d713d (patch)
tree2aac54f0b333430e003965341962651e3dc8b821 /firmware/drivers/eeprom_24cxx.c
parent11e2e565ca65e9555bcc19ddb256775e9e911edb (diff)
downloadrockbox-f14f59f9f387964687fda05b3881a090fb7d713d.tar.gz
rockbox-f14f59f9f387964687fda05b3881a090fb7d713d.zip
Data cache for the EEPROM driver to speed up reading/writing. This
will be my last iriver commit for a while due to a bricked H140. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@11602 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'firmware/drivers/eeprom_24cxx.c')
-rw-r--r--firmware/drivers/eeprom_24cxx.c60
1 files changed, 36 insertions, 24 deletions
diff --git a/firmware/drivers/eeprom_24cxx.c b/firmware/drivers/eeprom_24cxx.c
index e045a13fa6..20ad1dfebe 100644
--- a/firmware/drivers/eeprom_24cxx.c
+++ b/firmware/drivers/eeprom_24cxx.c
@@ -25,6 +25,7 @@
#include "logf.h"
#include "sprintf.h"
#include "string.h"
+#include "inttypes.h"
#include "eeprom_24cxx.h"
@@ -57,6 +58,10 @@
/* delay loop to achieve 400kHz at 120MHz CPU frequency */
#define DELAY do { int _x; for(_x=0;_x<22;_x++);} while(0)
+/* Use cache to speedup writing to the chip. */
+static char data_cache[EEPROM_SIZE];
+static uint8_t cached_bitfield[EEPROM_SIZE/8];
+
static void sw_i2c_init(void)
{
logf("sw_i2c_init");
@@ -280,8 +285,12 @@ int sw_i2c_read(unsigned char location, unsigned char* byte)
void eeprom_24cxx_init(void)
{
sw_i2c_init();
+ memset(cached_bitfield, 0, sizeof cached_bitfield);
}
+#define IS_CACHED(addr) (cached_bitfield[addr/8] & (1 << (addr % 8)))
+#define SET_CACHED(addr) (cached_bitfield[addr/8] |= 1 << (addr % 8))
+
int eeprom_24cxx_read_byte(unsigned int address, char *c)
{
int ret;
@@ -294,6 +303,14 @@ int eeprom_24cxx_read_byte(unsigned int address, char *c)
return -9;
}
+ /* Check from cache. */
+ if (IS_CACHED(address))
+ {
+ logf("EEPROM RCached: %d", address);
+ *c = data_cache[address];
+ return 0;
+ }
+
*c = 0;
do
{
@@ -311,7 +328,11 @@ int eeprom_24cxx_read_byte(unsigned int address, char *c)
/* keep between {} as logf is whitespace in normal builds */
logf("EEPROM rOK: %d retries", count);
}
-
+
+ /* Cache the byte. */
+ data_cache[address] = byte;
+ SET_CACHED(address);
+
*c = byte;
return 0;
}
@@ -327,6 +348,13 @@ int eeprom_24cxx_write_byte(unsigned int address, char c)
return -9;
}
+ /* Check from cache. */
+ if (IS_CACHED(address) && data_cache[address] == c)
+ {
+ logf("EEPROM WCached: %d", address);
+ return 0;
+ }
+
do
{
ret = sw_i2c_write_byte(address, c);
@@ -344,6 +372,9 @@ int eeprom_24cxx_write_byte(unsigned int address, char c)
logf("EEPROM wOK: %d retries", count);
}
+ SET_CACHED(address);
+ data_cache[address] = c;
+
return 0;
}
@@ -366,33 +397,14 @@ int eeprom_24cxx_read(unsigned char address, void *dest, int length)
int eeprom_24cxx_write(unsigned char address, const void *src, int length)
{
const char *buf = (const char *)src;
- int count = 5;
int i;
- bool ok;
- while (count-- > 0)
+ for (i = 0; i < length; i++)
{
- for (i = 0; i < length; i++)
- eeprom_24cxx_write_byte(address+i, buf[i]);
-
- ok = true;
- for (i = 0; i < length; i++)
- {
- char byte;
-
- eeprom_24cxx_read_byte(address+i, &byte);
- if (byte != buf[i])
- {
- logf("Verify failed: %d/%d", address+i, count);
- ok = false;
- break;
- }
- }
-
- if (ok)
- return 0;
+ if (eeprom_24cxx_write_byte(address+i, buf[i]) < 0)
+ return -1;
}
- return -1;
+ return 0;
}