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I2C overhaul part 3: "we finally figured out NCR NVRAM" edition

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This commit is contained in:
RichardG867
2020-11-21 01:36:33 -03:00
parent cf2dba5838
commit d5867928d6
8 changed files with 214 additions and 235 deletions
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58
src/device/i2c_eeprom.c
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@@ -6,7 +6,7 @@
*
* This file is part of the 86Box distribution.
*
* Emulation of the AT24Cxx series of I2C EEPROMs.
* Emulation of the 24Cxx series of I2C EEPROMs.
*
*
*
@@ -27,22 +27,42 @@
typedef struct {
void *i2c;
uint8_t addr;
uint8_t *data;
uint8_t writable;
uint8_t addr, *data, writable;
uint16_t addr_mask;
uint8_t addr_register;
uint16_t addr_mask, addr_register;
uint8_t i2c_state;
} i2c_eeprom_t;
#define ENABLE_I2C_EEPROM_LOG 1
#ifdef ENABLE_I2C_EEPROM_LOG
int i2c_eeprom_do_log = ENABLE_I2C_EEPROM_LOG;
static void
i2c_eeprom_log(const char *fmt, ...)
{
va_list ap;
if (i2c_eeprom_do_log) {
va_start(ap, fmt);
pclog_ex(fmt, ap);
va_end(ap);
}
}
#else
#define i2c_eeprom_log(fmt, ...)
#endif
void
i2c_eeprom_start(void *bus, uint8_t addr, void *priv)
{
i2c_eeprom_t *dev = (i2c_eeprom_t *) priv;
i2c_eeprom_log("I2C EEPROM: start()\n");
dev->i2c_state = 0;
dev->addr_register = (addr << 8) & dev->addr_mask;
}
@@ -50,8 +70,13 @@ uint8_t
i2c_eeprom_read(void *bus, uint8_t addr, void *priv)
{
i2c_eeprom_t *dev = (i2c_eeprom_t *) priv;
uint8_t ret = dev->data[dev->addr_register];
return dev->data[((addr << 8) | dev->addr_register++) & dev->addr_mask];
i2c_eeprom_log("I2C EEPROM: read(%04X) = %02X\n", dev->addr_register, ret);
if (++dev->addr_register > dev->addr_mask) /* roll-over */
dev->addr_register = 0;
return ret;
}
@@ -62,11 +87,16 @@ i2c_eeprom_write(void *bus, uint8_t addr, uint8_t data, void *priv)
if (dev->i2c_state == 0) {
dev->i2c_state = 1;
dev->addr_register = data;
} else if (dev->writable)
dev->data[((addr << 8) | dev->addr_register++) & dev->addr_mask] = data;
else
return 0;
dev->addr_register = ((addr << 8) | data) & dev->addr_mask;
i2c_eeprom_log("I2C EEPROM: write(address, %04X)\n", dev->addr_register);
} else {
i2c_eeprom_log("I2C EEPROM: write(%04X, %02X) = %s\n", dev->addr_register, data, dev->writable ? "accepted" : "blocked");
if (dev->writable)
dev->data[dev->addr_register] = data;
if (++dev->addr_register > dev->addr_mask) /* roll-over */
dev->addr_register = 0;
return dev->writable;
}
return 1;
}
@@ -78,6 +108,8 @@ i2c_eeprom_init(void *i2c, uint8_t addr, uint8_t *data, uint16_t size, uint8_t w
i2c_eeprom_t *dev = (i2c_eeprom_t *) malloc(sizeof(i2c_eeprom_t));
memset(dev, 0, sizeof(i2c_eeprom_t));
i2c_eeprom_log("I2C EEPROM: init(%02X, %d, %d)\n", addr, size, writable);
dev->i2c = i2c;
dev->addr = addr;
dev->data = data;
@@ -96,6 +128,8 @@ i2c_eeprom_close(void *dev_handle)
{
i2c_eeprom_t *dev = (i2c_eeprom_t *) dev_handle;
i2c_eeprom_log("I2C EEPROM: close()\n");
i2c_removehandler(dev->i2c, dev->addr & ~(dev->addr_mask >> 8), (dev->addr_mask >> 8) + 1, i2c_eeprom_start, i2c_eeprom_read, i2c_eeprom_write, NULL, dev);
free(dev);