@@ -592,7 +592,7 @@ obj-arm-y += omap2.o omap_dss.o soc_dma.o
obj-arm-y += omap_sx1.o palm.o tsc210x.o
obj-arm-y += nseries.o blizzard.o onenand.o vga.o cbus.o tusb6010.o usb-musb.o
obj-arm-y += mst_fpga.o mainstone.o
-obj-arm-y += musicpal.o pflash_cfi02.o
+obj-arm-y += musicpal.o pflash_cfi02.o bitbang_i2c.o
obj-arm-y += framebuffer.o
obj-arm-y += syborg.o syborg_fb.o syborg_interrupt.o syborg_keyboard.o
obj-arm-y += syborg_serial.o syborg_timer.o syborg_pointer.o syborg_rtc.o
new file mode 100644
@@ -0,0 +1,179 @@
+/*
+ * Bit-Bang i2c emulation extracted from
+ * Marvell MV88W8618 / Freecom MusicPal emulation.
+ *
+ * Copyright (c) 2008 Jan Kiszka
+ *
+ * This code is licenced under the GNU GPL v2.
+ */
+#include "hw.h"
+#include "i2c.h"
+#include "sysbus.h"
+
+typedef enum bitbang_i2c_state {
+ STOPPED = 0,
+ INITIALIZING,
+ SENDING_BIT7,
+ SENDING_BIT6,
+ SENDING_BIT5,
+ SENDING_BIT4,
+ SENDING_BIT3,
+ SENDING_BIT2,
+ SENDING_BIT1,
+ SENDING_BIT0,
+ WAITING_FOR_ACK,
+ RECEIVING_BIT7,
+ RECEIVING_BIT6,
+ RECEIVING_BIT5,
+ RECEIVING_BIT4,
+ RECEIVING_BIT3,
+ RECEIVING_BIT2,
+ RECEIVING_BIT1,
+ RECEIVING_BIT0,
+ SENDING_ACK
+} bitbang_i2c_state;
+
+typedef struct bitbang_i2c_interface {
+ SysBusDevice busdev;
+ i2c_bus *bus;
+ bitbang_i2c_state state;
+ int last_data;
+ int last_clock;
+ uint8_t buffer;
+ int current_addr;
+ qemu_irq out;
+} bitbang_i2c_interface;
+
+static void bitbang_i2c_enter_stop(bitbang_i2c_interface *i2c)
+{
+ if (i2c->current_addr >= 0)
+ i2c_end_transfer(i2c->bus);
+ i2c->current_addr = -1;
+ i2c->state = STOPPED;
+}
+
+static void bitbang_i2c_gpio_set(void *opaque, int irq, int level)
+{
+ bitbang_i2c_interface *i2c = opaque;
+ int data;
+ int clock;
+ int data_goes_up;
+ int data_goes_down;
+ int clock_goes_up;
+ int clock_goes_down;
+
+ /* get pins states */
+ data = i2c->last_data;
+ clock = i2c->last_clock;
+
+ if (irq == 0)
+ data = level;
+ if (irq == 1)
+ clock = level;
+
+ /* compute pins changes */
+ data_goes_up = data == 1 && i2c->last_data == 0;
+ data_goes_down = data == 0 && i2c->last_data == 1;
+ clock_goes_up = clock == 1 && i2c->last_clock == 0;
+ clock_goes_down = clock == 0 && i2c->last_clock == 1;
+
+ if (data_goes_up == 0 && data_goes_down == 0 &&
+ clock_goes_up == 0 && clock_goes_down == 0)
+ return;
+
+ if (!i2c)
+ return;
+
+ if ((RECEIVING_BIT7 > i2c->state && i2c->state > RECEIVING_BIT0)
+ || i2c->state == WAITING_FOR_ACK)
+ qemu_set_irq(i2c->out, 0);
+
+ switch (i2c->state) {
+ case STOPPED:
+ if (data_goes_down && clock == 1)
+ i2c->state = INITIALIZING;
+ break;
+
+ case INITIALIZING:
+ if (clock_goes_down && data == 0)
+ i2c->state = SENDING_BIT7;
+ else
+ bitbang_i2c_enter_stop(i2c);
+ break;
+
+ case SENDING_BIT7 ... SENDING_BIT0:
+ if (clock_goes_down) {
+ i2c->buffer = (i2c->buffer << 1) | data;
+ /* will end up in WAITING_FOR_ACK */
+ i2c->state++;
+ } else if (data_goes_up && clock == 1)
+ bitbang_i2c_enter_stop(i2c);
+ break;
+
+ case WAITING_FOR_ACK:
+ if (clock_goes_down) {
+ if (i2c->current_addr < 0) {
+ i2c->current_addr = i2c->buffer;
+ i2c_start_transfer(i2c->bus, (i2c->current_addr & 0xfe) / 2,
+ i2c->buffer & 1);
+ } else
+ i2c_send(i2c->bus, i2c->buffer);
+ if (i2c->current_addr & 1) {
+ i2c->state = RECEIVING_BIT7;
+ i2c->buffer = i2c_recv(i2c->bus);
+ } else
+ i2c->state = SENDING_BIT7;
+ } else if (data_goes_up && clock == 1)
+ bitbang_i2c_enter_stop(i2c);
+ break;
+
+ case RECEIVING_BIT7 ... RECEIVING_BIT0:
+ qemu_set_irq(i2c->out, i2c->buffer >> 7);
+ if (clock_goes_down) {
+ /* will end up in SENDING_ACK */
+ i2c->state++;
+ i2c->buffer <<= 1;
+ } else if (data_goes_up && clock == 1)
+ bitbang_i2c_enter_stop(i2c);
+ break;
+
+ case SENDING_ACK:
+ if (clock_goes_down) {
+ i2c->state = RECEIVING_BIT7;
+ if (data == 0)
+ i2c->buffer = i2c_recv(i2c->bus);
+ else
+ i2c_nack(i2c->bus);
+ } else if (data_goes_up && clock == 1)
+ bitbang_i2c_enter_stop(i2c);
+ break;
+ }
+
+ i2c->last_data = data;
+ i2c->last_clock = clock;
+}
+
+static void bitbang_i2c_init(SysBusDevice *dev)
+{
+ bitbang_i2c_interface *s = FROM_SYSBUS(bitbang_i2c_interface, dev);
+ i2c_bus *bus;
+
+ sysbus_init_mmio(dev, 0x0, 0);
+
+ bus = i2c_init_bus(&dev->qdev, "i2c");
+ s->bus = bus;
+
+ s->last_data = 1;
+ s->last_clock = 1;
+
+ qdev_init_gpio_in(&dev->qdev, bitbang_i2c_gpio_set, 2);
+ qdev_init_gpio_out(&dev->qdev, &s->out, 1);
+}
+
+static void bitbang_i2c_register(void)
+{
+ sysbus_register_dev("bitbang_i2c",
+ sizeof(bitbang_i2c_interface), bitbang_i2c_init);
+}
+
+device_init(bitbang_i2c_register)
Signed-off-by: Benoit Canet <benoit.canet@gmail.com> --- Makefile.target | 2 +- hw/bitbang_i2c.c | 179 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 180 insertions(+), 1 deletions(-) create mode 100644 hw/bitbang_i2c.c