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 "qemu/osdep.h" 11 #include "hw/i2c/i2c.h" 12 13 #define TYPE_MAX7310 "max7310" 14 #define MAX7310(obj) OBJECT_CHECK(MAX7310State, (obj), TYPE_MAX7310) 15 16 typedef struct MAX7310State { 17 I2CSlave parent_obj; 18 19 int i2c_command_byte; 20 int len; 21 22 uint8_t level; 23 uint8_t direction; 24 uint8_t polarity; 25 uint8_t status; 26 uint8_t command; 27 qemu_irq handler[8]; 28 qemu_irq *gpio_in; 29 } MAX7310State; 30 31 static void max7310_reset(DeviceState *dev) 32 { 33 MAX7310State *s = MAX7310(dev); 34 35 s->level &= s->direction; 36 s->direction = 0xff; 37 s->polarity = 0xf0; 38 s->status = 0x01; 39 s->command = 0x00; 40 } 41 42 static uint8_t max7310_rx(I2CSlave *i2c) 43 { 44 MAX7310State *s = MAX7310(i2c); 45 46 switch (s->command) { 47 case 0x00: /* Input port */ 48 return s->level ^ s->polarity; 49 break; 50 51 case 0x01: /* Output port */ 52 return s->level & ~s->direction; 53 break; 54 55 case 0x02: /* Polarity inversion */ 56 return s->polarity; 57 58 case 0x03: /* Configuration */ 59 return s->direction; 60 61 case 0x04: /* Timeout */ 62 return s->status; 63 break; 64 65 case 0xff: /* Reserved */ 66 return 0xff; 67 68 default: 69 #ifdef VERBOSE 70 printf("%s: unknown register %02x\n", __func__, s->command); 71 #endif 72 break; 73 } 74 return 0xff; 75 } 76 77 static int max7310_tx(I2CSlave *i2c, uint8_t data) 78 { 79 MAX7310State *s = MAX7310(i2c); 80 uint8_t diff; 81 int line; 82 83 if (s->len ++ > 1) { 84 #ifdef VERBOSE 85 printf("%s: message too long (%i bytes)\n", __func__, s->len); 86 #endif 87 return 1; 88 } 89 90 if (s->i2c_command_byte) { 91 s->command = data; 92 s->i2c_command_byte = 0; 93 return 0; 94 } 95 96 switch (s->command) { 97 case 0x01: /* Output port */ 98 for (diff = (data ^ s->level) & ~s->direction; diff; 99 diff &= ~(1 << line)) { 100 line = ctz32(diff); 101 if (s->handler[line]) 102 qemu_set_irq(s->handler[line], (data >> line) & 1); 103 } 104 s->level = (s->level & s->direction) | (data & ~s->direction); 105 break; 106 107 case 0x02: /* Polarity inversion */ 108 s->polarity = data; 109 break; 110 111 case 0x03: /* Configuration */ 112 s->level &= ~(s->direction ^ data); 113 s->direction = data; 114 break; 115 116 case 0x04: /* Timeout */ 117 s->status = data; 118 break; 119 120 case 0x00: /* Input port - ignore writes */ 121 break; 122 default: 123 #ifdef VERBOSE 124 printf("%s: unknown register %02x\n", __func__, s->command); 125 #endif 126 return 1; 127 } 128 129 return 0; 130 } 131 132 static int max7310_event(I2CSlave *i2c, enum i2c_event event) 133 { 134 MAX7310State *s = MAX7310(i2c); 135 s->len = 0; 136 137 switch (event) { 138 case I2C_START_SEND: 139 s->i2c_command_byte = 1; 140 break; 141 case I2C_FINISH: 142 #ifdef VERBOSE 143 if (s->len == 1) 144 printf("%s: message too short (%i bytes)\n", __func__, s->len); 145 #endif 146 break; 147 default: 148 break; 149 } 150 151 return 0; 152 } 153 154 static const VMStateDescription vmstate_max7310 = { 155 .name = "max7310", 156 .version_id = 0, 157 .minimum_version_id = 0, 158 .fields = (VMStateField[]) { 159 VMSTATE_INT32(i2c_command_byte, MAX7310State), 160 VMSTATE_INT32(len, MAX7310State), 161 VMSTATE_UINT8(level, MAX7310State), 162 VMSTATE_UINT8(direction, MAX7310State), 163 VMSTATE_UINT8(polarity, MAX7310State), 164 VMSTATE_UINT8(status, MAX7310State), 165 VMSTATE_UINT8(command, MAX7310State), 166 VMSTATE_I2C_SLAVE(parent_obj, MAX7310State), 167 VMSTATE_END_OF_LIST() 168 } 169 }; 170 171 static void max7310_gpio_set(void *opaque, int line, int level) 172 { 173 MAX7310State *s = (MAX7310State *) opaque; 174 if (line >= ARRAY_SIZE(s->handler) || line < 0) 175 hw_error("bad GPIO line"); 176 177 if (level) 178 s->level |= s->direction & (1 << line); 179 else 180 s->level &= ~(s->direction & (1 << line)); 181 } 182 183 /* MAX7310 is SMBus-compatible (can be used with only SMBus protocols), 184 * but also accepts sequences that are not SMBus so return an I2C device. */ 185 static void max7310_realize(DeviceState *dev, Error **errp) 186 { 187 I2CSlave *i2c = I2C_SLAVE(dev); 188 MAX7310State *s = MAX7310(dev); 189 190 qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8); 191 qdev_init_gpio_out(&i2c->qdev, s->handler, 8); 192 } 193 194 static void max7310_class_init(ObjectClass *klass, void *data) 195 { 196 DeviceClass *dc = DEVICE_CLASS(klass); 197 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); 198 199 dc->realize = max7310_realize; 200 k->event = max7310_event; 201 k->recv = max7310_rx; 202 k->send = max7310_tx; 203 dc->reset = max7310_reset; 204 dc->vmsd = &vmstate_max7310; 205 } 206 207 static const TypeInfo max7310_info = { 208 .name = TYPE_MAX7310, 209 .parent = TYPE_I2C_SLAVE, 210 .instance_size = sizeof(MAX7310State), 211 .class_init = max7310_class_init, 212 }; 213 214 static void max7310_register_types(void) 215 { 216 type_register_static(&max7310_info); 217 } 218 219 type_init(max7310_register_types) 220