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hw/at24c : modify at24c to support 1 byte address mode

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Signed-off-by: Sittisak Sinprem <ssinprem@celestica.com>
Reviewed-by: Peter Delevoryas <peter@pjd.dev>
[ clg: checkpatch issues ]
Message-Id: <167660539263.10409.9736070122710923479-1@git.sr.ht>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This commit is contained in:
Sittisak Sinprem 2023-03-02 13:57:50 +01:00 committed by Cédric Le Goater
parent 6c323aba40
commit 1e001a5a71
1 changed files with 27 additions and 3 deletions
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30
hw/nvram/eeprom_at24c.c
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@ -41,6 +41,13 @@ struct EEPROMState {
uint16_t cur;
/* total size in bytes */
uint32_t rsize;
/*
* address byte number
* for 24c01, 24c02 size <= 256 byte, use only 1 byte
* otherwise size > 256, use 2 byte
*/
uint8_t asize;
bool writable;
/* cells changed since last START? */
bool changed;
@ -91,7 +98,11 @@ uint8_t at24c_eeprom_recv(I2CSlave *s)
EEPROMState *ee = AT24C_EE(s);
uint8_t ret;
if (ee->haveaddr == 1) {
/*
* If got the byte address but not completely with address size
* will return the invalid value
*/
if (ee->haveaddr > 0 && ee->haveaddr < ee->asize) {
return 0xff;
}
@ -108,11 +119,11 @@ int at24c_eeprom_send(I2CSlave *s, uint8_t data)
{
EEPROMState *ee = AT24C_EE(s);
if (ee->haveaddr < 2) {
if (ee->haveaddr < ee->asize) {
ee->cur <<= 8;
ee->cur |= data;
ee->haveaddr++;
if (ee->haveaddr == 2) {
if (ee->haveaddr == ee->asize) {
ee->cur %= ee->rsize;
DPRINTK("Set pointer %04x\n", ee->cur);
}
@ -199,6 +210,18 @@ static void at24c_eeprom_realize(DeviceState *dev, Error **errp)
}
DPRINTK("Reset read backing file\n");
}
/*
* If address size didn't define with property set
* value is 0 as default, setting it by Rom size detecting.
*/
if (ee->asize == 0) {
if (ee->rsize <= 256) {
ee->asize = 1;
} else {
ee->asize = 2;
}
}
}
static
@ -213,6 +236,7 @@ void at24c_eeprom_reset(DeviceState *state)
static Property at24c_eeprom_props[] = {
DEFINE_PROP_UINT32("rom-size", EEPROMState, rsize, 0),
DEFINE_PROP_UINT8("address-size", EEPROMState, asize, 0),
DEFINE_PROP_BOOL("writable", EEPROMState, writable, true),
DEFINE_PROP_DRIVE("drive", EEPROMState, blk),
DEFINE_PROP_END_OF_LIST()