diff options
Diffstat (limited to 'qemu/hw/i2c/bitbang_i2c.c')
| -rw-r--r-- | qemu/hw/i2c/bitbang_i2c.c | 253 |
1 files changed, 0 insertions, 253 deletions
diff --git a/qemu/hw/i2c/bitbang_i2c.c b/qemu/hw/i2c/bitbang_i2c.c deleted file mode 100644 index 6ed206020..000000000 --- a/qemu/hw/i2c/bitbang_i2c.c +++ /dev/null @@ -1,253 +0,0 @@ -/* - * Bit-Bang i2c emulation extracted from - * Marvell MV88W8618 / Freecom MusicPal emulation. - * - * Copyright (c) 2008 Jan Kiszka - * - * This code is licensed under the GNU GPL v2. - * - * Contributions after 2012-01-13 are licensed under the terms of the - * GNU GPL, version 2 or (at your option) any later version. - */ -#include "qemu/osdep.h" -#include "hw/hw.h" -#include "bitbang_i2c.h" -#include "hw/sysbus.h" - -//#define DEBUG_BITBANG_I2C - -#ifdef DEBUG_BITBANG_I2C -#define DPRINTF(fmt, ...) \ -do { printf("bitbang_i2c: " fmt , ## __VA_ARGS__); } while (0) -#else -#define DPRINTF(fmt, ...) do {} while(0) -#endif - -typedef enum bitbang_i2c_state { - STOPPED = 0, - 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, - SENT_NACK -} bitbang_i2c_state; - -struct bitbang_i2c_interface { - I2CBus *bus; - bitbang_i2c_state state; - int last_data; - int last_clock; - int device_out; - uint8_t buffer; - int current_addr; -}; - -static void bitbang_i2c_enter_stop(bitbang_i2c_interface *i2c) -{ - DPRINTF("STOP\n"); - if (i2c->current_addr >= 0) - i2c_end_transfer(i2c->bus); - i2c->current_addr = -1; - i2c->state = STOPPED; -} - -/* Set device data pin. */ -static int bitbang_i2c_ret(bitbang_i2c_interface *i2c, int level) -{ - i2c->device_out = level; - //DPRINTF("%d %d %d\n", i2c->last_clock, i2c->last_data, i2c->device_out); - return level & i2c->last_data; -} - -/* Leave device data pin unodified. */ -static int bitbang_i2c_nop(bitbang_i2c_interface *i2c) -{ - return bitbang_i2c_ret(i2c, i2c->device_out); -} - -/* Returns data line level. */ -int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level) -{ - int data; - - if (level != 0 && level != 1) { - abort(); - } - - if (line == BITBANG_I2C_SDA) { - if (level == i2c->last_data) { - return bitbang_i2c_nop(i2c); - } - i2c->last_data = level; - if (i2c->last_clock == 0) { - return bitbang_i2c_nop(i2c); - } - if (level == 0) { - DPRINTF("START\n"); - /* START condition. */ - i2c->state = SENDING_BIT7; - i2c->current_addr = -1; - } else { - /* STOP condition. */ - bitbang_i2c_enter_stop(i2c); - } - return bitbang_i2c_ret(i2c, 1); - } - - data = i2c->last_data; - if (i2c->last_clock == level) { - return bitbang_i2c_nop(i2c); - } - i2c->last_clock = level; - if (level == 0) { - /* State is set/read at the start of the clock pulse. - release the data line at the end. */ - return bitbang_i2c_ret(i2c, 1); - } - switch (i2c->state) { - case STOPPED: - case SENT_NACK: - return bitbang_i2c_ret(i2c, 1); - - case SENDING_BIT7 ... SENDING_BIT0: - i2c->buffer = (i2c->buffer << 1) | data; - /* will end up in WAITING_FOR_ACK */ - i2c->state++; - return bitbang_i2c_ret(i2c, 1); - - case WAITING_FOR_ACK: - if (i2c->current_addr < 0) { - i2c->current_addr = i2c->buffer; - DPRINTF("Address 0x%02x\n", i2c->current_addr); - i2c_start_transfer(i2c->bus, i2c->current_addr >> 1, - i2c->current_addr & 1); - } else { - DPRINTF("Sent 0x%02x\n", i2c->buffer); - i2c_send(i2c->bus, i2c->buffer); - } - if (i2c->current_addr & 1) { - i2c->state = RECEIVING_BIT7; - } else { - i2c->state = SENDING_BIT7; - } - return bitbang_i2c_ret(i2c, 0); - - case RECEIVING_BIT7: - i2c->buffer = i2c_recv(i2c->bus); - DPRINTF("RX byte 0x%02x\n", i2c->buffer); - /* Fall through... */ - case RECEIVING_BIT6 ... RECEIVING_BIT0: - data = i2c->buffer >> 7; - /* will end up in SENDING_ACK */ - i2c->state++; - i2c->buffer <<= 1; - return bitbang_i2c_ret(i2c, data); - - case SENDING_ACK: - i2c->state = RECEIVING_BIT7; - if (data != 0) { - DPRINTF("NACKED\n"); - i2c->state = SENT_NACK; - i2c_nack(i2c->bus); - } else { - DPRINTF("ACKED\n"); - } - return bitbang_i2c_ret(i2c, 1); - } - abort(); -} - -bitbang_i2c_interface *bitbang_i2c_init(I2CBus *bus) -{ - bitbang_i2c_interface *s; - - s = g_malloc0(sizeof(bitbang_i2c_interface)); - - s->bus = bus; - s->last_data = 1; - s->last_clock = 1; - s->device_out = 1; - - return s; -} - -/* GPIO interface. */ - -#define TYPE_GPIO_I2C "gpio_i2c" -#define GPIO_I2C(obj) OBJECT_CHECK(GPIOI2CState, (obj), TYPE_GPIO_I2C) - -typedef struct GPIOI2CState { - SysBusDevice parent_obj; - - MemoryRegion dummy_iomem; - bitbang_i2c_interface *bitbang; - int last_level; - qemu_irq out; -} GPIOI2CState; - -static void bitbang_i2c_gpio_set(void *opaque, int irq, int level) -{ - GPIOI2CState *s = opaque; - - level = bitbang_i2c_set(s->bitbang, irq, level); - if (level != s->last_level) { - s->last_level = level; - qemu_set_irq(s->out, level); - } -} - -static int gpio_i2c_init(SysBusDevice *sbd) -{ - DeviceState *dev = DEVICE(sbd); - GPIOI2CState *s = GPIO_I2C(dev); - I2CBus *bus; - - memory_region_init(&s->dummy_iomem, OBJECT(s), "gpio_i2c", 0); - sysbus_init_mmio(sbd, &s->dummy_iomem); - - bus = i2c_init_bus(dev, "i2c"); - s->bitbang = bitbang_i2c_init(bus); - - qdev_init_gpio_in(dev, bitbang_i2c_gpio_set, 2); - qdev_init_gpio_out(dev, &s->out, 1); - - return 0; -} - -static void gpio_i2c_class_init(ObjectClass *klass, void *data) -{ - DeviceClass *dc = DEVICE_CLASS(klass); - SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass); - - k->init = gpio_i2c_init; - set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories); - dc->desc = "Virtual GPIO to I2C bridge"; -} - -static const TypeInfo gpio_i2c_info = { - .name = TYPE_GPIO_I2C, - .parent = TYPE_SYS_BUS_DEVICE, - .instance_size = sizeof(GPIOI2CState), - .class_init = gpio_i2c_class_init, -}; - -static void bitbang_i2c_register_types(void) -{ - type_register_static(&gpio_i2c_info); -} - -type_init(bitbang_i2c_register_types) |