/* * 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.h" #include "i2c.h" struct max7310_s { 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; }; void max7310_reset(i2c_slave *i2c) { struct max7310_s *s = (struct max7310_s *) i2c; s->level &= s->direction; s->direction = 0xff; s->polarity = 0xf0; s->status = 0x01; s->command = 0x00; } static int max7310_rx(i2c_slave *i2c) { struct max7310_s *s = (struct max7310_s *) 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) { struct max7310_s *s = (struct max7310_s *) 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) { struct max7310_s *s = (struct max7310_s *) i2c; s->len = 0; switch (event) { case I2C_START_SEND: s->i2c_command_byte = 1; break; case I2C_FINISH: if (s->len == 1) #ifdef VERBOSE printf("%s: message too short (%i bytes)\n", __FUNCTION__, s->len); #endif break; default: break; } } static void max7310_save(QEMUFile *f, void *opaque) { struct max7310_s *s = (struct max7310_s *) opaque; qemu_put_be32(f, s->i2c_command_byte); qemu_put_be32(f, s->len); qemu_put_8s(f, &s->level); qemu_put_8s(f, &s->direction); qemu_put_8s(f, &s->polarity); qemu_put_8s(f, &s->status); qemu_put_8s(f, &s->command); i2c_slave_save(f, &s->i2c); } static int max7310_load(QEMUFile *f, void *opaque, int version_id) { struct max7310_s *s = (struct max7310_s *) opaque; s->i2c_command_byte = qemu_get_be32(f); s->len = qemu_get_be32(f); qemu_get_8s(f, &s->level); qemu_get_8s(f, &s->direction); qemu_get_8s(f, &s->polarity); qemu_get_8s(f, &s->status); qemu_get_8s(f, &s->command); i2c_slave_load(f, &s->i2c); return 0; } static int max7310_iid = 0; static void max7310_gpio_set(void *opaque, int line, int level) { struct max7310_s *s = (struct max7310_s *) opaque; if (line >= sizeof(s->handler) / sizeof(*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. */ struct i2c_slave *max7310_init(i2c_bus *bus) { struct max7310_s *s = (struct max7310_s *) i2c_slave_init(bus, 0, sizeof(struct max7310_s)); s->i2c.event = max7310_event; s->i2c.recv = max7310_rx; s->i2c.send = max7310_tx; s->gpio_in = qemu_allocate_irqs(max7310_gpio_set, s, sizeof(s->handler) / sizeof(*s->handler)); max7310_reset(&s->i2c); register_savevm("max7310", max7310_iid ++, 0, max7310_save, max7310_load, s); return &s->i2c; } qemu_irq *max7310_gpio_in_get(i2c_slave *i2c) { struct max7310_s *s = (struct max7310_s *) i2c; return s->gpio_in; } void max7310_gpio_out_set(i2c_slave *i2c, int line, qemu_irq handler) { struct max7310_s *s = (struct max7310_s *) i2c; if (line >= sizeof(s->handler) / sizeof(*s->handler) || line < 0) hw_error("bad GPIO line"); s->handler[line] = handler; }