1 /* 2 * MAX7310 8-port GPIO expansion chip. 3 * 4 * Copyright (c) 2006 Openedhand Ltd. 5 * Written by Andrzej Zaborowski <balrog@zabor.org> 6 * 7 * This file is licensed under GNU GPL. 8 */ 9 10 #include "hw/i2c/i2c.h" 11 12 typedef struct { 13 I2CSlave i2c; 14 int i2c_command_byte; 15 int len; 16 17 uint8_t level; 18 uint8_t direction; 19 uint8_t polarity; 20 uint8_t status; 21 uint8_t command; 22 qemu_irq handler[8]; 23 qemu_irq *gpio_in; 24 } MAX7310State; 25 26 static void max7310_reset(DeviceState *dev) 27 { 28 MAX7310State *s = FROM_I2C_SLAVE(MAX7310State, I2C_SLAVE(dev)); 29 s->level &= s->direction; 30 s->direction = 0xff; 31 s->polarity = 0xf0; 32 s->status = 0x01; 33 s->command = 0x00; 34 } 35 36 static int max7310_rx(I2CSlave *i2c) 37 { 38 MAX7310State *s = (MAX7310State *) i2c; 39 40 switch (s->command) { 41 case 0x00: /* Input port */ 42 return s->level ^ s->polarity; 43 break; 44 45 case 0x01: /* Output port */ 46 return s->level & ~s->direction; 47 break; 48 49 case 0x02: /* Polarity inversion */ 50 return s->polarity; 51 52 case 0x03: /* Configuration */ 53 return s->direction; 54 55 case 0x04: /* Timeout */ 56 return s->status; 57 break; 58 59 case 0xff: /* Reserved */ 60 return 0xff; 61 62 default: 63 #ifdef VERBOSE 64 printf("%s: unknown register %02x\n", __FUNCTION__, s->command); 65 #endif 66 break; 67 } 68 return 0xff; 69 } 70 71 static int max7310_tx(I2CSlave *i2c, uint8_t data) 72 { 73 MAX7310State *s = (MAX7310State *) i2c; 74 uint8_t diff; 75 int line; 76 77 if (s->len ++ > 1) { 78 #ifdef VERBOSE 79 printf("%s: message too long (%i bytes)\n", __FUNCTION__, s->len); 80 #endif 81 return 1; 82 } 83 84 if (s->i2c_command_byte) { 85 s->command = data; 86 s->i2c_command_byte = 0; 87 return 0; 88 } 89 90 switch (s->command) { 91 case 0x01: /* Output port */ 92 for (diff = (data ^ s->level) & ~s->direction; diff; 93 diff &= ~(1 << line)) { 94 line = ffs(diff) - 1; 95 if (s->handler[line]) 96 qemu_set_irq(s->handler[line], (data >> line) & 1); 97 } 98 s->level = (s->level & s->direction) | (data & ~s->direction); 99 break; 100 101 case 0x02: /* Polarity inversion */ 102 s->polarity = data; 103 break; 104 105 case 0x03: /* Configuration */ 106 s->level &= ~(s->direction ^ data); 107 s->direction = data; 108 break; 109 110 case 0x04: /* Timeout */ 111 s->status = data; 112 break; 113 114 case 0x00: /* Input port - ignore writes */ 115 break; 116 default: 117 #ifdef VERBOSE 118 printf("%s: unknown register %02x\n", __FUNCTION__, s->command); 119 #endif 120 return 1; 121 } 122 123 return 0; 124 } 125 126 static void max7310_event(I2CSlave *i2c, enum i2c_event event) 127 { 128 MAX7310State *s = (MAX7310State *) i2c; 129 s->len = 0; 130 131 switch (event) { 132 case I2C_START_SEND: 133 s->i2c_command_byte = 1; 134 break; 135 case I2C_FINISH: 136 #ifdef VERBOSE 137 if (s->len == 1) 138 printf("%s: message too short (%i bytes)\n", __FUNCTION__, s->len); 139 #endif 140 break; 141 default: 142 break; 143 } 144 } 145 146 static const VMStateDescription vmstate_max7310 = { 147 .name = "max7310", 148 .version_id = 0, 149 .minimum_version_id = 0, 150 .minimum_version_id_old = 0, 151 .fields = (VMStateField []) { 152 VMSTATE_INT32(i2c_command_byte, MAX7310State), 153 VMSTATE_INT32(len, MAX7310State), 154 VMSTATE_UINT8(level, MAX7310State), 155 VMSTATE_UINT8(direction, MAX7310State), 156 VMSTATE_UINT8(polarity, MAX7310State), 157 VMSTATE_UINT8(status, MAX7310State), 158 VMSTATE_UINT8(command, MAX7310State), 159 VMSTATE_I2C_SLAVE(i2c, MAX7310State), 160 VMSTATE_END_OF_LIST() 161 } 162 }; 163 164 static void max7310_gpio_set(void *opaque, int line, int level) 165 { 166 MAX7310State *s = (MAX7310State *) opaque; 167 if (line >= ARRAY_SIZE(s->handler) || line < 0) 168 hw_error("bad GPIO line"); 169 170 if (level) 171 s->level |= s->direction & (1 << line); 172 else 173 s->level &= ~(s->direction & (1 << line)); 174 } 175 176 /* MAX7310 is SMBus-compatible (can be used with only SMBus protocols), 177 * but also accepts sequences that are not SMBus so return an I2C device. */ 178 static int max7310_init(I2CSlave *i2c) 179 { 180 MAX7310State *s = FROM_I2C_SLAVE(MAX7310State, i2c); 181 182 qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8); 183 qdev_init_gpio_out(&i2c->qdev, s->handler, 8); 184 185 return 0; 186 } 187 188 static void max7310_class_init(ObjectClass *klass, void *data) 189 { 190 DeviceClass *dc = DEVICE_CLASS(klass); 191 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); 192 193 k->init = max7310_init; 194 k->event = max7310_event; 195 k->recv = max7310_rx; 196 k->send = max7310_tx; 197 dc->reset = max7310_reset; 198 dc->vmsd = &vmstate_max7310; 199 } 200 201 static const TypeInfo max7310_info = { 202 .name = "max7310", 203 .parent = TYPE_I2C_SLAVE, 204 .instance_size = sizeof(MAX7310State), 205 .class_init = max7310_class_init, 206 }; 207 208 static void max7310_register_types(void) 209 { 210 type_register_static(&max7310_info); 211 } 212 213 type_init(max7310_register_types) 214