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/*
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* MAX7310 8-port GPIO expansion chip.
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*
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* Copyright (c) 2006 Openedhand Ltd.
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* Written by Andrzej Zaborowski <balrog@zabor.org>
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*
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* This file is licensed under GNU GPL.
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*/
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#include "i2c.h" |
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typedef struct { |
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i2c_slave i2c; |
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int i2c_command_byte;
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int len;
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uint8_t level; |
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uint8_t direction; |
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uint8_t polarity; |
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uint8_t status; |
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uint8_t command; |
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qemu_irq handler[8];
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qemu_irq *gpio_in; |
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} MAX7310State; |
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void max7310_reset(i2c_slave *i2c)
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{ |
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MAX7310State *s = (MAX7310State *) i2c; |
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s->level &= s->direction; |
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s->direction = 0xff;
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s->polarity = 0xf0;
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s->status = 0x01;
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s->command = 0x00;
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} |
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static int max7310_rx(i2c_slave *i2c) |
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{ |
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MAX7310State *s = (MAX7310State *) i2c; |
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switch (s->command) {
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case 0x00: /* Input port */ |
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return s->level ^ s->polarity;
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break;
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case 0x01: /* Output port */ |
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return s->level & ~s->direction;
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break;
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case 0x02: /* Polarity inversion */ |
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return s->polarity;
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case 0x03: /* Configuration */ |
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return s->direction;
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case 0x04: /* Timeout */ |
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return s->status;
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break;
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case 0xff: /* Reserved */ |
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return 0xff; |
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default:
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#ifdef VERBOSE
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printf("%s: unknown register %02x\n", __FUNCTION__, s->command);
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#endif
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break;
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} |
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return 0xff; |
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} |
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static int max7310_tx(i2c_slave *i2c, uint8_t data) |
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{ |
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MAX7310State *s = (MAX7310State *) i2c; |
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uint8_t diff; |
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int line;
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if (s->len ++ > 1) { |
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#ifdef VERBOSE
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printf("%s: message too long (%i bytes)\n", __FUNCTION__, s->len);
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#endif
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return 1; |
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} |
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if (s->i2c_command_byte) {
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s->command = data; |
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s->i2c_command_byte = 0;
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return 0; |
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} |
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switch (s->command) {
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case 0x01: /* Output port */ |
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for (diff = (data ^ s->level) & ~s->direction; diff;
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diff &= ~(1 << line)) {
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line = ffs(diff) - 1;
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if (s->handler[line])
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qemu_set_irq(s->handler[line], (data >> line) & 1);
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} |
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s->level = (s->level & s->direction) | (data & ~s->direction); |
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break;
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case 0x02: /* Polarity inversion */ |
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s->polarity = data; |
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break;
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case 0x03: /* Configuration */ |
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s->level &= ~(s->direction ^ data); |
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s->direction = data; |
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break;
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case 0x04: /* Timeout */ |
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s->status = data; |
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break;
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case 0x00: /* Input port - ignore writes */ |
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break;
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default:
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#ifdef VERBOSE
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printf("%s: unknown register %02x\n", __FUNCTION__, s->command);
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#endif
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return 1; |
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} |
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return 0; |
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} |
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static void max7310_event(i2c_slave *i2c, enum i2c_event event) |
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{ |
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MAX7310State *s = (MAX7310State *) i2c; |
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s->len = 0;
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switch (event) {
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case I2C_START_SEND:
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s->i2c_command_byte = 1;
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break;
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case I2C_FINISH:
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#ifdef VERBOSE
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if (s->len == 1) |
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printf("%s: message too short (%i bytes)\n", __FUNCTION__, s->len);
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#endif
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break;
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default:
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break;
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} |
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} |
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static void max7310_save(QEMUFile *f, void *opaque) |
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{ |
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MAX7310State *s = (MAX7310State *) opaque; |
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qemu_put_be32(f, s->i2c_command_byte); |
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qemu_put_be32(f, s->len); |
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qemu_put_8s(f, &s->level); |
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qemu_put_8s(f, &s->direction); |
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qemu_put_8s(f, &s->polarity); |
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qemu_put_8s(f, &s->status); |
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qemu_put_8s(f, &s->command); |
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i2c_slave_save(f, &s->i2c); |
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} |
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static int max7310_load(QEMUFile *f, void *opaque, int version_id) |
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{ |
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MAX7310State *s = (MAX7310State *) opaque; |
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s->i2c_command_byte = qemu_get_be32(f); |
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s->len = qemu_get_be32(f); |
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qemu_get_8s(f, &s->level); |
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qemu_get_8s(f, &s->direction); |
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qemu_get_8s(f, &s->polarity); |
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qemu_get_8s(f, &s->status); |
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qemu_get_8s(f, &s->command); |
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i2c_slave_load(f, &s->i2c); |
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return 0; |
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} |
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static void max7310_gpio_set(void *opaque, int line, int level) |
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{ |
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MAX7310State *s = (MAX7310State *) opaque; |
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if (line >= ARRAY_SIZE(s->handler) || line < 0) |
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hw_error("bad GPIO line");
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if (level)
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s->level |= s->direction & (1 << line);
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else
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s->level &= ~(s->direction & (1 << line));
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} |
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/* MAX7310 is SMBus-compatible (can be used with only SMBus protocols),
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* but also accepts sequences that are not SMBus so return an I2C device. */
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static void max7310_init(i2c_slave *i2c) |
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{ |
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MAX7310State *s = FROM_I2C_SLAVE(MAX7310State, i2c); |
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s->gpio_in = qemu_allocate_irqs(max7310_gpio_set, s, |
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ARRAY_SIZE(s->handler)); |
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max7310_reset(&s->i2c); |
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register_savevm("max7310", -1, 0, max7310_save, max7310_load, s); |
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} |
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qemu_irq *max7310_gpio_in_get(i2c_slave *i2c) |
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{ |
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MAX7310State *s = (MAX7310State *) i2c; |
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return s->gpio_in;
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} |
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void max7310_gpio_out_set(i2c_slave *i2c, int line, qemu_irq handler) |
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{ |
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MAX7310State *s = (MAX7310State *) i2c; |
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if (line >= ARRAY_SIZE(s->handler) || line < 0) |
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hw_error("bad GPIO line");
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s->handler[line] = handler; |
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} |
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static I2CSlaveInfo max7310_info = {
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.init = max7310_init, |
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.event = max7310_event, |
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.recv = max7310_rx, |
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.send = max7310_tx |
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}; |
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static void max7310_register_devices(void) |
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{ |
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i2c_register_slave("max7310", sizeof(MAX7310State), &max7310_info); |
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} |
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device_init(max7310_register_devices) |