Commit 130751ee authored by ths's avatar ths
Browse files

24C01 / 24C02 EEPROM emulation for Malta, by Stefan Weil.


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2458 c046a42c-6fe2-441c-8c8c-71466251a162
parent d7739d75
......@@ -49,6 +49,7 @@ typedef struct {
uint32_t leds;
uint32_t brk;
uint32_t gpout;
uint32_t i2cin;
uint32_t i2coe;
uint32_t i2cout;
uint32_t i2csel;
......@@ -83,6 +84,124 @@ static void malta_fpga_update_display(void *opaque)
qemu_chr_printf(s->display, "\n\n\n\n|\e[31m%-8.8s\e[00m|", s->display_text);
}
/*
* EEPROM 24C01 / 24C02 emulation.
*
* Emulation for serial EEPROMs:
* 24C01 - 1024 bit (128 x 8)
* 24C02 - 2048 bit (256 x 8)
*
* Typical device names include Microchip 24C02SC or SGS Thomson ST24C02.
*/
//~ #define DEBUG
#if defined(DEBUG)
# define logout(fmt, args...) fprintf(stderr, "MALTA\t%-24s" fmt, __func__, ##args)
#else
# define logout(fmt, args...) ((void)0)
#endif
struct _eeprom24c0x_t {
uint8_t tick;
uint8_t address;
uint8_t command;
uint8_t ack;
uint8_t scl;
uint8_t sda;
uint8_t data;
//~ uint16_t size;
uint8_t contents[256];
};
typedef struct _eeprom24c0x_t eeprom24c0x_t;
static eeprom24c0x_t eeprom = {
contents: {
/* 00000000: */ 0x80,0x08,0x04,0x0D,0x0A,0x01,0x40,0x00,
/* 00000008: */ 0x01,0x75,0x54,0x00,0x82,0x08,0x00,0x01,
/* 00000010: */ 0x8F,0x04,0x02,0x01,0x01,0x00,0x0E,0x00,
/* 00000018: */ 0x00,0x00,0x00,0x14,0x0F,0x14,0x2D,0x40,
/* 00000020: */ 0x15,0x08,0x15,0x08,0x00,0x00,0x00,0x00,
/* 00000028: */ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
/* 00000030: */ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
/* 00000038: */ 0x00,0x00,0x00,0x00,0x00,0x00,0x12,0xD0,
/* 00000040: */ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
/* 00000048: */ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
/* 00000050: */ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
/* 00000058: */ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
/* 00000060: */ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
/* 00000068: */ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
/* 00000070: */ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
/* 00000078: */ 0x00,0x00,0x00,0x00,0x00,0x00,0x64,0xF4,
},
};
static uint8_t eeprom24c0x_read()
{
logout("%u: scl = %u, sda = %u, data = 0x%02x\n",
eeprom.tick, eeprom.scl, eeprom.sda, eeprom.data);
return eeprom.sda;
}
static void eeprom24c0x_write(int scl, int sda)
{
if (eeprom.scl && scl && (eeprom.sda != sda)) {
logout("%u: scl = %u->%u, sda = %u->%u i2c %s\n",
eeprom.tick, eeprom.scl, scl, eeprom.sda, sda, sda ? "stop" : "start");
if (!sda) {
eeprom.tick = 1;
eeprom.command = 0;
}
} else if (eeprom.tick == 0 && !eeprom.ack) {
/* Waiting for start. */
logout("%u: scl = %u->%u, sda = %u->%u wait for i2c start\n",
eeprom.tick, eeprom.scl, scl, eeprom.sda, sda);
} else if (!eeprom.scl && scl) {
logout("%u: scl = %u->%u, sda = %u->%u trigger bit\n",
eeprom.tick, eeprom.scl, scl, eeprom.sda, sda);
if (eeprom.ack) {
logout("\ti2c ack bit = 0\n");
sda = 0;
eeprom.ack = 0;
} else if (eeprom.sda == sda) {
uint8_t bit = (sda != 0);
logout("\ti2c bit = %d\n", bit);
if (eeprom.tick < 9) {
eeprom.command <<= 1;
eeprom.command += bit;
eeprom.tick++;
if (eeprom.tick == 9) {
logout("\tcommand 0x%04x, %s\n", eeprom.command, bit ? "read" : "write");
eeprom.ack = 1;
}
} else if (eeprom.tick < 17) {
if (eeprom.command & 1) {
sda = ((eeprom.data & 0x80) != 0);
}
eeprom.address <<= 1;
eeprom.address += bit;
eeprom.tick++;
eeprom.data <<= 1;
if (eeprom.tick == 17) {
eeprom.data = eeprom.contents[eeprom.address];
logout("\taddress 0x%04x, data 0x%02x\n", eeprom.address, eeprom.data);
eeprom.ack = 1;
eeprom.tick = 0;
}
} else if (eeprom.tick >= 17) {
sda = 0;
}
} else {
logout("\tsda changed with raising scl\n");
}
} else {
logout("%u: scl = %u->%u, sda = %u->%u\n", eeprom.tick, eeprom.scl, scl, eeprom.sda, sda);
}
eeprom.scl = scl;
eeprom.sda = sda;
}
static uint32_t malta_fpga_readl(void *opaque, target_phys_addr_t addr)
{
MaltaFPGAState *s = opaque;
......@@ -140,7 +259,7 @@ static uint32_t malta_fpga_readl(void *opaque, target_phys_addr_t addr)
/* I2CINP Register */
case 0x00b00:
val = 0x00000003;
val = ((s->i2cin & ~1) | eeprom24c0x_read());
break;
/* I2COE Register */
......@@ -155,7 +274,7 @@ static uint32_t malta_fpga_readl(void *opaque, target_phys_addr_t addr)
/* I2CSEL Register */
case 0x00b18:
val = s->i2cout;
val = s->i2csel;
break;
default:
......@@ -234,12 +353,13 @@ static void malta_fpga_writel(void *opaque, target_phys_addr_t addr,
/* I2COUT Register */
case 0x00b10:
s->i2cout = val & 0x03;
eeprom24c0x_write(val & 0x02, val & 0x01);
s->i2cout = val;
break;
/* I2CSEL Register */
case 0x00b18:
s->i2cout = val & 0x01;
s->i2csel = val & 0x01;
break;
default:
......@@ -270,6 +390,7 @@ void malta_fpga_reset(void *opaque)
s->leds = 0x00;
s->brk = 0x0a;
s->gpout = 0x00;
s->i2cin = 0x3;
s->i2coe = 0x0;
s->i2cout = 0x3;
s->i2csel = 0x1;
......
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