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 "hw/irq.h" 13 #include "qemu/module.h" 14 15 #define TYPE_MAX7310 "max7310" 16 #define MAX7310(obj) OBJECT_CHECK(MAX7310State, (obj), TYPE_MAX7310) 17 18 typedef struct MAX7310State { 19 I2CSlave parent_obj; 20 21 int i2c_command_byte; 22 int len; 23 24 uint8_t level; 25 uint8_t direction; 26 uint8_t polarity; 27 uint8_t status; 28 uint8_t command; 29 qemu_irq handler[8]; 30 qemu_irq *gpio_in; 31 } MAX7310State; 32 33 static void max7310_reset(DeviceState *dev) 34 { 35 MAX7310State *s = MAX7310(dev); 36 37 s->level &= s->direction; 38 s->direction = 0xff; 39 s->polarity = 0xf0; 40 s->status = 0x01; 41 s->command = 0x00; 42 } 43 44 static uint8_t max7310_rx(I2CSlave *i2c) 45 { 46 MAX7310State *s = MAX7310(i2c); 47 48 switch (s->command) { 49 case 0x00: /* Input port */ 50 return s->level ^ s->polarity; 51 break; 52 53 case 0x01: /* Output port */ 54 return s->level & ~s->direction; 55 break; 56 57 case 0x02: /* Polarity inversion */ 58 return s->polarity; 59 60 case 0x03: /* Configuration */ 61 return s->direction; 62 63 case 0x04: /* Timeout */ 64 return s->status; 65 break; 66 67 case 0xff: /* Reserved */ 68 return 0xff; 69 70 default: 71 #ifdef VERBOSE 72 printf("%s: unknown register %02x\n", __func__, s->command); 73 #endif 74 break; 75 } 76 return 0xff; 77 } 78 79 static int max7310_tx(I2CSlave *i2c, uint8_t data) 80 { 81 MAX7310State *s = MAX7310(i2c); 82 uint8_t diff; 83 int line; 84 85 if (s->len ++ > 1) { 86 #ifdef VERBOSE 87 printf("%s: message too long (%i bytes)\n", __func__, s->len); 88 #endif 89 return 1; 90 } 91 92 if (s->i2c_command_byte) { 93 s->command = data; 94 s->i2c_command_byte = 0; 95 return 0; 96 } 97 98 switch (s->command) { 99 case 0x01: /* Output port */ 100 for (diff = (data ^ s->level) & ~s->direction; diff; 101 diff &= ~(1 << line)) { 102 line = ctz32(diff); 103 if (s->handler[line]) 104 qemu_set_irq(s->handler[line], (data >> line) & 1); 105 } 106 s->level = (s->level & s->direction) | (data & ~s->direction); 107 break; 108 109 case 0x02: /* Polarity inversion */ 110 s->polarity = data; 111 break; 112 113 case 0x03: /* Configuration */ 114 s->level &= ~(s->direction ^ data); 115 s->direction = data; 116 break; 117 118 case 0x04: /* Timeout */ 119 s->status = data; 120 break; 121 122 case 0x00: /* Input port - ignore writes */ 123 break; 124 default: 125 #ifdef VERBOSE 126 printf("%s: unknown register %02x\n", __func__, s->command); 127 #endif 128 return 1; 129 } 130 131 return 0; 132 } 133 134 static int max7310_event(I2CSlave *i2c, enum i2c_event event) 135 { 136 MAX7310State *s = MAX7310(i2c); 137 s->len = 0; 138 139 switch (event) { 140 case I2C_START_SEND: 141 s->i2c_command_byte = 1; 142 break; 143 case I2C_FINISH: 144 #ifdef VERBOSE 145 if (s->len == 1) 146 printf("%s: message too short (%i bytes)\n", __func__, s->len); 147 #endif 148 break; 149 default: 150 break; 151 } 152 153 return 0; 154 } 155 156 static const VMStateDescription vmstate_max7310 = { 157 .name = "max7310", 158 .version_id = 0, 159 .minimum_version_id = 0, 160 .fields = (VMStateField[]) { 161 VMSTATE_INT32(i2c_command_byte, MAX7310State), 162 VMSTATE_INT32(len, MAX7310State), 163 VMSTATE_UINT8(level, MAX7310State), 164 VMSTATE_UINT8(direction, MAX7310State), 165 VMSTATE_UINT8(polarity, MAX7310State), 166 VMSTATE_UINT8(status, MAX7310State), 167 VMSTATE_UINT8(command, MAX7310State), 168 VMSTATE_I2C_SLAVE(parent_obj, MAX7310State), 169 VMSTATE_END_OF_LIST() 170 } 171 }; 172 173 static void max7310_gpio_set(void *opaque, int line, int level) 174 { 175 MAX7310State *s = (MAX7310State *) opaque; 176 if (line >= ARRAY_SIZE(s->handler) || line < 0) 177 hw_error("bad GPIO line"); 178 179 if (level) 180 s->level |= s->direction & (1 << line); 181 else 182 s->level &= ~(s->direction & (1 << line)); 183 } 184 185 /* MAX7310 is SMBus-compatible (can be used with only SMBus protocols), 186 * but also accepts sequences that are not SMBus so return an I2C device. */ 187 static void max7310_realize(DeviceState *dev, Error **errp) 188 { 189 I2CSlave *i2c = I2C_SLAVE(dev); 190 MAX7310State *s = MAX7310(dev); 191 192 qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8); 193 qdev_init_gpio_out(&i2c->qdev, s->handler, 8); 194 } 195 196 static void max7310_class_init(ObjectClass *klass, void *data) 197 { 198 DeviceClass *dc = DEVICE_CLASS(klass); 199 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); 200 201 dc->realize = max7310_realize; 202 k->event = max7310_event; 203 k->recv = max7310_rx; 204 k->send = max7310_tx; 205 dc->reset = max7310_reset; 206 dc->vmsd = &vmstate_max7310; 207 } 208 209 static const TypeInfo max7310_info = { 210 .name = TYPE_MAX7310, 211 .parent = TYPE_I2C_SLAVE, 212 .instance_size = sizeof(MAX7310State), 213 .class_init = max7310_class_init, 214 }; 215 216 static void max7310_register_types(void) 217 { 218 type_register_static(&max7310_info); 219 } 220 221 type_init(max7310_register_types) 222