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 #include "qemu/module.h" 13 14 #define TYPE_MAX7310 "max7310" 15 #define MAX7310(obj) OBJECT_CHECK(MAX7310State, (obj), TYPE_MAX7310) 16 17 typedef struct MAX7310State { 18 I2CSlave parent_obj; 19 20 int i2c_command_byte; 21 int len; 22 23 uint8_t level; 24 uint8_t direction; 25 uint8_t polarity; 26 uint8_t status; 27 uint8_t command; 28 qemu_irq handler[8]; 29 qemu_irq *gpio_in; 30 } MAX7310State; 31 32 static void max7310_reset(DeviceState *dev) 33 { 34 MAX7310State *s = MAX7310(dev); 35 36 s->level &= s->direction; 37 s->direction = 0xff; 38 s->polarity = 0xf0; 39 s->status = 0x01; 40 s->command = 0x00; 41 } 42 43 static uint8_t max7310_rx(I2CSlave *i2c) 44 { 45 MAX7310State *s = MAX7310(i2c); 46 47 switch (s->command) { 48 case 0x00: /* Input port */ 49 return s->level ^ s->polarity; 50 break; 51 52 case 0x01: /* Output port */ 53 return s->level & ~s->direction; 54 break; 55 56 case 0x02: /* Polarity inversion */ 57 return s->polarity; 58 59 case 0x03: /* Configuration */ 60 return s->direction; 61 62 case 0x04: /* Timeout */ 63 return s->status; 64 break; 65 66 case 0xff: /* Reserved */ 67 return 0xff; 68 69 default: 70 #ifdef VERBOSE 71 printf("%s: unknown register %02x\n", __func__, s->command); 72 #endif 73 break; 74 } 75 return 0xff; 76 } 77 78 static int max7310_tx(I2CSlave *i2c, uint8_t data) 79 { 80 MAX7310State *s = MAX7310(i2c); 81 uint8_t diff; 82 int line; 83 84 if (s->len ++ > 1) { 85 #ifdef VERBOSE 86 printf("%s: message too long (%i bytes)\n", __func__, s->len); 87 #endif 88 return 1; 89 } 90 91 if (s->i2c_command_byte) { 92 s->command = data; 93 s->i2c_command_byte = 0; 94 return 0; 95 } 96 97 switch (s->command) { 98 case 0x01: /* Output port */ 99 for (diff = (data ^ s->level) & ~s->direction; diff; 100 diff &= ~(1 << line)) { 101 line = ctz32(diff); 102 if (s->handler[line]) 103 qemu_set_irq(s->handler[line], (data >> line) & 1); 104 } 105 s->level = (s->level & s->direction) | (data & ~s->direction); 106 break; 107 108 case 0x02: /* Polarity inversion */ 109 s->polarity = data; 110 break; 111 112 case 0x03: /* Configuration */ 113 s->level &= ~(s->direction ^ data); 114 s->direction = data; 115 break; 116 117 case 0x04: /* Timeout */ 118 s->status = data; 119 break; 120 121 case 0x00: /* Input port - ignore writes */ 122 break; 123 default: 124 #ifdef VERBOSE 125 printf("%s: unknown register %02x\n", __func__, s->command); 126 #endif 127 return 1; 128 } 129 130 return 0; 131 } 132 133 static int max7310_event(I2CSlave *i2c, enum i2c_event event) 134 { 135 MAX7310State *s = MAX7310(i2c); 136 s->len = 0; 137 138 switch (event) { 139 case I2C_START_SEND: 140 s->i2c_command_byte = 1; 141 break; 142 case I2C_FINISH: 143 #ifdef VERBOSE 144 if (s->len == 1) 145 printf("%s: message too short (%i bytes)\n", __func__, s->len); 146 #endif 147 break; 148 default: 149 break; 150 } 151 152 return 0; 153 } 154 155 static const VMStateDescription vmstate_max7310 = { 156 .name = "max7310", 157 .version_id = 0, 158 .minimum_version_id = 0, 159 .fields = (VMStateField[]) { 160 VMSTATE_INT32(i2c_command_byte, MAX7310State), 161 VMSTATE_INT32(len, MAX7310State), 162 VMSTATE_UINT8(level, MAX7310State), 163 VMSTATE_UINT8(direction, MAX7310State), 164 VMSTATE_UINT8(polarity, MAX7310State), 165 VMSTATE_UINT8(status, MAX7310State), 166 VMSTATE_UINT8(command, MAX7310State), 167 VMSTATE_I2C_SLAVE(parent_obj, MAX7310State), 168 VMSTATE_END_OF_LIST() 169 } 170 }; 171 172 static void max7310_gpio_set(void *opaque, int line, int level) 173 { 174 MAX7310State *s = (MAX7310State *) opaque; 175 if (line >= ARRAY_SIZE(s->handler) || line < 0) 176 hw_error("bad GPIO line"); 177 178 if (level) 179 s->level |= s->direction & (1 << line); 180 else 181 s->level &= ~(s->direction & (1 << line)); 182 } 183 184 /* MAX7310 is SMBus-compatible (can be used with only SMBus protocols), 185 * but also accepts sequences that are not SMBus so return an I2C device. */ 186 static void max7310_realize(DeviceState *dev, Error **errp) 187 { 188 I2CSlave *i2c = I2C_SLAVE(dev); 189 MAX7310State *s = MAX7310(dev); 190 191 qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8); 192 qdev_init_gpio_out(&i2c->qdev, s->handler, 8); 193 } 194 195 static void max7310_class_init(ObjectClass *klass, void *data) 196 { 197 DeviceClass *dc = DEVICE_CLASS(klass); 198 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); 199 200 dc->realize = max7310_realize; 201 k->event = max7310_event; 202 k->recv = max7310_rx; 203 k->send = max7310_tx; 204 dc->reset = max7310_reset; 205 dc->vmsd = &vmstate_max7310; 206 } 207 208 static const TypeInfo max7310_info = { 209 .name = TYPE_MAX7310, 210 .parent = TYPE_I2C_SLAVE, 211 .instance_size = sizeof(MAX7310State), 212 .class_init = max7310_class_init, 213 }; 214 215 static void max7310_register_types(void) 216 { 217 type_register_static(&max7310_info); 218 } 219 220 type_init(max7310_register_types) 221