Move i2c_eeprom to mem/ directory

2020-11-30 20:08:37 -03:00
parent f6be8931ff
commit 2579f7fb83
2 changed files with 29 additions and 13 deletions
--- a/src/mem/i2c_eeprom.c
+++ b/src/mem/i2c_eeprom.c
@@ -0,0 +1,161 @@
+/*
+ * 86Box	A hypervisor and IBM PC system emulator that specializes in
+ *		running old operating systems and software designed for IBM
+ *		PC systems and compatibles from 1981 through fairly recent
+ *		system designs based on the PCI bus.
+ *
+ *		This file is part of the 86Box distribution.
+ *
+ *		Emulation of the 24Cxx series of I2C EEPROMs.
+ *
+ *
+ *
+ * Authors:	RichardG, <richardg867@gmail.com>
+ *
+ *		Copyright 2020 RichardG.
+ */
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#define HAVE_STDARG_H
+#include <wchar.h>
+#include <86box/86box.h>
+#include <86box/i2c.h>
+
+
+typedef struct {
+    void	*i2c;
+    uint8_t	addr, *data, writable;
+
+    uint32_t	addr_mask, addr_register;
+    uint8_t	addr_len, addr_pos;
+} 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
+
+
+static uint8_t
+i2c_eeprom_start(void *bus, uint8_t addr, uint8_t read, void *priv)
+{
+    i2c_eeprom_t *dev = (i2c_eeprom_t *) priv;
+
+    i2c_eeprom_log("I2C EEPROM %s %02X: start()\n", i2c_getbusname(dev->i2c), dev->addr);
+
+    if (!read) {
+    	dev->addr_pos = 0;
+    	dev->addr_register = (addr << dev->addr_len) & dev->addr_mask;
+    }
+
+    return 1;
+}
+
+
+static 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];
+
+    i2c_eeprom_log("I2C EEPROM %s %02X: read(%06X) = %02X\n", i2c_getbusname(dev->i2c), dev->addr, dev->addr_register, ret);
+    dev->addr_register++;
+    dev->addr_register &= dev->addr_mask; /* roll-over */
+
+    return ret;
+}
+
+
+static uint8_t
+i2c_eeprom_write(void *bus, uint8_t addr, uint8_t data, void *priv)
+{
+    i2c_eeprom_t *dev = (i2c_eeprom_t *) priv;
+
+    if (dev->addr_pos < dev->addr_len) {
+	dev->addr_register <<= 8;
+	dev->addr_register |= data;
+	dev->addr_register &= (1 << dev->addr_len) - 1;
+	dev->addr_register |= addr << dev->addr_len;
+	dev->addr_register &= dev->addr_mask;
+	i2c_eeprom_log("I2C EEPROM %s %02X: write(address, %06X)\n", i2c_getbusname(dev->i2c), dev->addr, dev->addr_register);
+	dev->addr_pos += 8;
+    } else {
+	i2c_eeprom_log("I2C EEPROM %s %02X: write(%06X, %02X) = %d\n", i2c_getbusname(dev->i2c), dev->addr, dev->addr_register, data, !!dev->writable);
+	if (dev->writable)
+		dev->data[dev->addr_register] = data;
+	dev->addr_register++;
+	dev->addr_register &= dev->addr_mask; /* roll-over */
+	return dev->writable;
+    }
+
+    return 1;
+}
+
+
+uint8_t
+log2i(uint32_t i)
+{
+    uint8_t ret = 0;
+    while ((i >>= 1))
+	ret++;
+    return ret;
+}
+
+
+void *
+i2c_eeprom_init(void *i2c, uint8_t addr, uint8_t *data, uint32_t size, uint8_t writable)
+{
+    i2c_eeprom_t *dev = (i2c_eeprom_t *) malloc(sizeof(i2c_eeprom_t));
+    memset(dev, 0, sizeof(i2c_eeprom_t));
+
+    /* Round size up to the next power of 2. */
+    uint32_t pow_size = 1 << log2i(size);
+    if (pow_size < size)
+	size = pow_size << 1;
+    size &= 0x7fffff; /* address space limit of 8 MB = 7 bits from I2C address + 16 bits */
+
+    i2c_eeprom_log("I2C EEPROM %s %02X: init(%d, %d)\n", i2c_getbusname(i2c), addr, size, writable);
+
+    dev->i2c = i2c;
+    dev->addr = addr;
+    dev->data = data;
+    dev->writable = writable;
+
+    dev->addr_len = (size >= 4096) ? 16 : 8; /* use 16-bit addresses on 24C32 and above */
+    dev->addr_mask = size - 1;
+
+    i2c_sethandler(dev->i2c, dev->addr & ~(dev->addr_mask >> dev->addr_len), (dev->addr_mask >> dev->addr_len) + 1, i2c_eeprom_start, i2c_eeprom_read, i2c_eeprom_write, NULL, dev);
+
+    return dev;
+}
+
+
+void
+i2c_eeprom_close(void *dev_handle)
+{
+    i2c_eeprom_t *dev = (i2c_eeprom_t *) dev_handle;
+
+    i2c_eeprom_log("I2C EEPROM %s %02X: close()\n", i2c_getbusname(dev->i2c), dev->addr);
+
+    i2c_removehandler(dev->i2c, dev->addr & ~(dev->addr_mask >> dev->addr_len), (dev->addr_mask >> dev->addr_len) + 1, i2c_eeprom_start, i2c_eeprom_read, i2c_eeprom_write, NULL, dev);
+
+    free(dev);
+}