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-rw-r--r--hw/smbus.c303
1 files changed, 303 insertions, 0 deletions
diff --git a/hw/smbus.c b/hw/smbus.c
new file mode 100644
index 0000000000..651a7a0b97
--- /dev/null
+++ b/hw/smbus.c
@@ -0,0 +1,303 @@
+/*
+ * QEMU SMBus device emulation.
+ *
+ * Copyright (c) 2007 CodeSourcery.
+ * Written by Paul Brook
+ *
+ * This code is licenced under the LGPL.
+ */
+
+/* TODO: Implement PEC. */
+
+#include "vl.h"
+
+//#define DEBUG_SMBUS 1
+
+#ifdef DEBUG_SMBUS
+#define DPRINTF(fmt, args...) \
+do { printf("smbus(%02x): " fmt , dev->i2c.address, ##args); } while (0)
+#define BADF(fmt, args...) \
+do { fprintf(stderr, "smbus: error: " fmt , ##args); exit(1);} while (0)
+#else
+#define DPRINTF(fmt, args...) do {} while(0)
+#define BADF(fmt, args...) \
+do { fprintf(stderr, "smbus: error: " fmt , ##args);} while (0)
+#endif
+
+enum {
+ SMBUS_IDLE,
+ SMBUS_WRITE_DATA,
+ SMBUS_RECV_BYTE,
+ SMBUS_READ_DATA,
+ SMBUS_DONE,
+ SMBUS_CONFUSED = -1
+};
+
+static void smbus_do_quick_cmd(SMBusDevice *dev, int recv)
+{
+ DPRINTF("Quick Command %d\n", recv);
+ if (dev->quick_cmd)
+ dev->quick_cmd(dev, recv);
+}
+
+static void smbus_do_write(SMBusDevice *dev)
+{
+ if (dev->data_len == 0) {
+ smbus_do_quick_cmd(dev, 0);
+ } else if (dev->data_len == 1) {
+ DPRINTF("Send Byte\n");
+ if (dev->send_byte) {
+ dev->send_byte(dev, dev->data_buf[0]);
+ }
+ } else {
+ dev->command = dev->data_buf[0];
+ DPRINTF("Command %d len %d\n", dev->command, dev->data_len - 1);
+ if (dev->write_data) {
+ dev->write_data(dev, dev->command, dev->data_buf + 1,
+ dev->data_len - 1);
+ }
+ }
+}
+
+void smbus_i2c_event(i2c_slave *s, enum i2c_event event)
+{
+ SMBusDevice *dev = (SMBusDevice *)s;
+ switch (event) {
+ case I2C_START_SEND:
+ switch (dev->mode) {
+ case SMBUS_IDLE:
+ DPRINTF("Incoming data\n");
+ dev->mode = SMBUS_WRITE_DATA;
+ break;
+ default:
+ BADF("Unexpected send start condition in state %d\n", dev->mode);
+ dev->mode = SMBUS_CONFUSED;
+ break;
+ }
+ break;
+
+ case I2C_START_RECV:
+ switch (dev->mode) {
+ case SMBUS_IDLE:
+ DPRINTF("Read mode\n");
+ dev->mode = SMBUS_RECV_BYTE;
+ break;
+ case SMBUS_WRITE_DATA:
+ if (dev->data_len == 0) {
+ BADF("Read after write with no data\n");
+ dev->mode = SMBUS_CONFUSED;
+ } else {
+ if (dev->data_len > 1) {
+ smbus_do_write(dev);
+ } else {
+ dev->command = dev->data_buf[0];
+ DPRINTF("%02x: Command %d\n", dev->i2c.address,
+ dev->command);
+ }
+ DPRINTF("Read mode\n");
+ dev->data_len = 0;
+ dev->mode = SMBUS_READ_DATA;
+ }
+ break;
+ default:
+ BADF("Unexpected recv start condition in state %d\n", dev->mode);
+ dev->mode = SMBUS_CONFUSED;
+ break;
+ }
+ break;
+
+ case I2C_FINISH:
+ switch (dev->mode) {
+ case SMBUS_WRITE_DATA:
+ smbus_do_write(dev);
+ break;
+ case SMBUS_RECV_BYTE:
+ smbus_do_quick_cmd(dev, 1);
+ break;
+ case SMBUS_READ_DATA:
+ BADF("Unexpected stop during receive\n");
+ break;
+ default:
+ /* Nothing to do. */
+ break;
+ }
+ dev->mode = SMBUS_IDLE;
+ dev->data_len = 0;
+ break;
+
+ case I2C_NACK:
+ switch (dev->mode) {
+ case SMBUS_DONE:
+ /* Nothing to do. */
+ break;
+ case SMBUS_READ_DATA:
+ dev->mode = SMBUS_DONE;
+ break;
+ default:
+ BADF("Unexpected NACK in state %d\n", dev->mode);
+ dev->mode = SMBUS_CONFUSED;
+ break;
+ }
+ }
+}
+
+static int smbus_i2c_recv(i2c_slave *s)
+{
+ SMBusDevice *dev = (SMBusDevice *)s;
+ int ret;
+
+ switch (dev->mode) {
+ case SMBUS_RECV_BYTE:
+ if (dev->receive_byte) {
+ ret = dev->receive_byte(dev);
+ } else {
+ ret = 0;
+ }
+ DPRINTF("Receive Byte %02x\n", ret);
+ dev->mode = SMBUS_DONE;
+ break;
+ case SMBUS_READ_DATA:
+ if (dev->read_data) {
+ ret = dev->read_data(dev, dev->command, dev->data_len);
+ dev->data_len++;
+ } else {
+ ret = 0;
+ }
+ DPRINTF("Read data %02x\n", ret);
+ break;
+ default:
+ BADF("Unexpected read in state %d\n", dev->mode);
+ dev->mode = SMBUS_CONFUSED;
+ ret = 0;
+ break;
+ }
+ return ret;
+}
+
+static int smbus_i2c_send(i2c_slave *s, uint8_t data)
+{
+ SMBusDevice *dev = (SMBusDevice *)s;
+ switch (dev->mode) {
+ case SMBUS_WRITE_DATA:
+ DPRINTF("Write data %02x\n", data);
+ dev->data_buf[dev->data_len++] = data;
+ break;
+ default:
+ BADF("Unexpected write in state %d\n", dev->mode);
+ break;
+ }
+ return 0;
+}
+
+SMBusDevice *smbus_device_init(i2c_bus *bus, int address, int size)
+{
+ SMBusDevice *dev;
+
+ dev = (SMBusDevice *)i2c_slave_init(bus, address, size);
+ dev->i2c.event = smbus_i2c_event;
+ dev->i2c.recv = smbus_i2c_recv;
+ dev->i2c.send = smbus_i2c_send;
+
+ return dev;
+}
+
+/* Master device commands. */
+void smbus_quick_command(i2c_bus *bus, int addr, int read)
+{
+ i2c_start_transfer(bus, addr, read);
+ i2c_end_transfer(bus);
+}
+
+uint8_t smbus_receive_byte(i2c_bus *bus, int addr)
+{
+ uint8_t data;
+
+ i2c_start_transfer(bus, addr, 1);
+ data = i2c_recv(bus);
+ i2c_nack(bus);
+ i2c_end_transfer(bus);
+ return data;
+}
+
+void smbus_send_byte(i2c_bus *bus, int addr, uint8_t data)
+{
+ i2c_start_transfer(bus, addr, 0);
+ i2c_send(bus, data);
+ i2c_end_transfer(bus);
+}
+
+uint8_t smbus_read_byte(i2c_bus *bus, int addr, uint8_t command)
+{
+ uint8_t data;
+ i2c_start_transfer(bus, addr, 0);
+ i2c_send(bus, command);
+ i2c_start_transfer(bus, addr, 1);
+ data = i2c_recv(bus);
+ i2c_nack(bus);
+ i2c_end_transfer(bus);
+ return data;
+}
+
+void smbus_write_byte(i2c_bus *bus, int addr, uint8_t command, uint8_t data)
+{
+ i2c_start_transfer(bus, addr, 0);
+ i2c_send(bus, command);
+ i2c_send(bus, data);
+ i2c_end_transfer(bus);
+}
+
+uint16_t smbus_read_word(i2c_bus *bus, int addr, uint8_t command)
+{
+ uint16_t data;
+ i2c_start_transfer(bus, addr, 0);
+ i2c_send(bus, command);
+ i2c_start_transfer(bus, addr, 1);
+ data = i2c_recv(bus);
+ data |= i2c_recv(bus) << 8;
+ i2c_nack(bus);
+ i2c_end_transfer(bus);
+ return data;
+}
+
+void smbus_write_word(i2c_bus *bus, int addr, uint8_t command, uint16_t data)
+{
+ i2c_start_transfer(bus, addr, 0);
+ i2c_send(bus, command);
+ i2c_send(bus, data & 0xff);
+ i2c_send(bus, data >> 8);
+ i2c_end_transfer(bus);
+}
+
+int smbus_read_block(i2c_bus *bus, int addr, uint8_t command, uint8_t *data)
+{
+ int len;
+ int i;
+
+ i2c_start_transfer(bus, addr, 0);
+ i2c_send(bus, command);
+ i2c_start_transfer(bus, addr, 1);
+ len = i2c_recv(bus);
+ if (len > 32)
+ len = 0;
+ for (i = 0; i < len; i++)
+ data[i] = i2c_recv(bus);
+ i2c_nack(bus);
+ i2c_end_transfer(bus);
+ return len;
+}
+
+void smbus_write_block(i2c_bus *bus, int addr, uint8_t command, uint8_t *data,
+ int len)
+{
+ int i;
+
+ if (len > 32)
+ len = 32;
+
+ i2c_start_transfer(bus, addr, 0);
+ i2c_send(bus, command);
+ i2c_send(bus, len);
+ for (i = 0; i < len; i++)
+ i2c_send(bus, data[i]);
+ i2c_end_transfer(bus);
+}
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