diff options
Diffstat (limited to 'src/hw/gpio/max7310.c')
| -rw-r--r-- | src/hw/gpio/max7310.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/src/hw/gpio/max7310.c b/src/hw/gpio/max7310.c new file mode 100644 index 0000000..2f59b13 --- /dev/null +++ b/src/hw/gpio/max7310.c @@ -0,0 +1,217 @@ +/* + * MAX7310 8-port GPIO expansion chip. + * + * Copyright (c) 2006 Openedhand Ltd. + * Written by Andrzej Zaborowski <balrog@zabor.org> + * + * This file is licensed under GNU GPL. + */ + +#include "hw/i2c/i2c.h" + +#define TYPE_MAX7310 "max7310" +#define MAX7310(obj) OBJECT_CHECK(MAX7310State, (obj), TYPE_MAX7310) + +typedef struct MAX7310State { + I2CSlave parent_obj; + + int i2c_command_byte; + int len; + + uint8_t level; + uint8_t direction; + uint8_t polarity; + uint8_t status; + uint8_t command; + qemu_irq handler[8]; + qemu_irq *gpio_in; +} MAX7310State; + +static void max7310_reset(DeviceState *dev) +{ + MAX7310State *s = MAX7310(dev); + + s->level &= s->direction; + s->direction = 0xff; + s->polarity = 0xf0; + s->status = 0x01; + s->command = 0x00; +} + +static int max7310_rx(I2CSlave *i2c) +{ + MAX7310State *s = MAX7310(i2c); + + switch (s->command) { + case 0x00: /* Input port */ + return s->level ^ s->polarity; + break; + + case 0x01: /* Output port */ + return s->level & ~s->direction; + break; + + case 0x02: /* Polarity inversion */ + return s->polarity; + + case 0x03: /* Configuration */ + return s->direction; + + case 0x04: /* Timeout */ + return s->status; + break; + + case 0xff: /* Reserved */ + return 0xff; + + default: +#ifdef VERBOSE + printf("%s: unknown register %02x\n", __FUNCTION__, s->command); +#endif + break; + } + return 0xff; +} + +static int max7310_tx(I2CSlave *i2c, uint8_t data) +{ + MAX7310State *s = MAX7310(i2c); + uint8_t diff; + int line; + + if (s->len ++ > 1) { +#ifdef VERBOSE + printf("%s: message too long (%i bytes)\n", __FUNCTION__, s->len); +#endif + return 1; + } + + if (s->i2c_command_byte) { + s->command = data; + s->i2c_command_byte = 0; + return 0; + } + + switch (s->command) { + case 0x01: /* Output port */ + for (diff = (data ^ s->level) & ~s->direction; diff; + diff &= ~(1 << line)) { + line = ctz32(diff); + if (s->handler[line]) + qemu_set_irq(s->handler[line], (data >> line) & 1); + } + s->level = (s->level & s->direction) | (data & ~s->direction); + break; + + case 0x02: /* Polarity inversion */ + s->polarity = data; + break; + + case 0x03: /* Configuration */ + s->level &= ~(s->direction ^ data); + s->direction = data; + break; + + case 0x04: /* Timeout */ + s->status = data; + break; + + case 0x00: /* Input port - ignore writes */ + break; + default: +#ifdef VERBOSE + printf("%s: unknown register %02x\n", __FUNCTION__, s->command); +#endif + return 1; + } + + return 0; +} + +static void max7310_event(I2CSlave *i2c, enum i2c_event event) +{ + MAX7310State *s = MAX7310(i2c); + s->len = 0; + + switch (event) { + case I2C_START_SEND: + s->i2c_command_byte = 1; + break; + case I2C_FINISH: +#ifdef VERBOSE + if (s->len == 1) + printf("%s: message too short (%i bytes)\n", __FUNCTION__, s->len); +#endif + break; + default: + break; + } +} + +static const VMStateDescription vmstate_max7310 = { + .name = "max7310", + .version_id = 0, + .minimum_version_id = 0, + .fields = (VMStateField[]) { + VMSTATE_INT32(i2c_command_byte, MAX7310State), + VMSTATE_INT32(len, MAX7310State), + VMSTATE_UINT8(level, MAX7310State), + VMSTATE_UINT8(direction, MAX7310State), + VMSTATE_UINT8(polarity, MAX7310State), + VMSTATE_UINT8(status, MAX7310State), + VMSTATE_UINT8(command, MAX7310State), + VMSTATE_I2C_SLAVE(parent_obj, MAX7310State), + VMSTATE_END_OF_LIST() + } +}; + +static void max7310_gpio_set(void *opaque, int line, int level) +{ + MAX7310State *s = (MAX7310State *) opaque; + if (line >= ARRAY_SIZE(s->handler) || line < 0) + hw_error("bad GPIO line"); + + if (level) + s->level |= s->direction & (1 << line); + else + s->level &= ~(s->direction & (1 << line)); +} + +/* MAX7310 is SMBus-compatible (can be used with only SMBus protocols), + * but also accepts sequences that are not SMBus so return an I2C device. */ +static int max7310_init(I2CSlave *i2c) +{ + MAX7310State *s = MAX7310(i2c); + + qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8); + qdev_init_gpio_out(&i2c->qdev, s->handler, 8); + + return 0; +} + +static void max7310_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); + + k->init = max7310_init; + k->event = max7310_event; + k->recv = max7310_rx; + k->send = max7310_tx; + dc->reset = max7310_reset; + dc->vmsd = &vmstate_max7310; +} + +static const TypeInfo max7310_info = { + .name = TYPE_MAX7310, + .parent = TYPE_I2C_SLAVE, + .instance_size = sizeof(MAX7310State), + .class_init = max7310_class_init, +}; + +static void max7310_register_types(void) +{ + type_register_static(&max7310_info); +} + +type_init(max7310_register_types) |
