/* * 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 "i2c.h" typedef struct { i2c_slave i2c; 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 = FROM_I2C_SLAVE(MAX7310State, I2C_SLAVE_FROM_QDEV(dev)); s->level &= s->direction; s->direction = 0xff; s->polarity = 0xf0; s->status = 0x01; s->command = 0x00; } static int max7310_rx(i2c_slave *i2c) { MAX7310State *s = (MAX7310State *) 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(i2c_slave *i2c, uint8_t data) { MAX7310State *s = (MAX7310State *) 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 = ffs(diff) - 1; 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(i2c_slave *i2c, enum i2c_event event) { MAX7310State *s = (MAX7310State *) 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, .minimum_version_id_old = 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(i2c, 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(i2c_slave *i2c) { MAX7310State *s = FROM_I2C_SLAVE(MAX7310State, i2c); qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8); qdev_init_gpio_out(&i2c->qdev, s->handler, 8); return 0; } static I2CSlaveInfo max7310_info = { .qdev.name = "max7310", .qdev.size = sizeof(MAX7310State), .qdev.vmsd = &vmstate_max7310, .qdev.reset = max7310_reset, .init = max7310_init, .event = max7310_event, .recv = max7310_rx, .send = max7310_tx }; static void max7310_register_devices(void) { i2c_register_slave(&max7310_info); } device_init(max7310_register_devices)