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 "migration/vmstate.h" 14 #include "qemu/log.h" 15 #include "qemu/module.h" 16 #include "qom/object.h" 17 18 #define TYPE_MAX7310 "max7310" 19 typedef struct MAX7310State MAX7310State; 20 DECLARE_INSTANCE_CHECKER(MAX7310State, MAX7310, 21 TYPE_MAX7310) 22 23 struct MAX7310State { 24 I2CSlave parent_obj; 25 26 int i2c_command_byte; 27 int len; 28 29 uint8_t level; 30 uint8_t direction; 31 uint8_t polarity; 32 uint8_t status; 33 uint8_t command; 34 qemu_irq handler[8]; 35 qemu_irq *gpio_in; 36 }; 37 38 static void max7310_reset(DeviceState *dev) 39 { 40 MAX7310State *s = MAX7310(dev); 41 42 s->level &= s->direction; 43 s->direction = 0xff; 44 s->polarity = 0xf0; 45 s->status = 0x01; 46 s->command = 0x00; 47 } 48 49 static uint8_t max7310_rx(I2CSlave *i2c) 50 { 51 MAX7310State *s = MAX7310(i2c); 52 53 switch (s->command) { 54 case 0x00: /* Input port */ 55 return s->level ^ s->polarity; 56 57 case 0x01: /* Output port */ 58 return s->level & ~s->direction; 59 60 case 0x02: /* Polarity inversion */ 61 return s->polarity; 62 63 case 0x03: /* Configuration */ 64 return s->direction; 65 66 case 0x04: /* Timeout */ 67 return s->status; 68 69 case 0xff: /* Reserved */ 70 return 0xff; 71 72 default: 73 qemu_log_mask(LOG_UNIMP, "%s: Unsupported register 0x02%" PRIx8 "\n", 74 __func__, s->command); 75 break; 76 } 77 return 0xff; 78 } 79 80 static int max7310_tx(I2CSlave *i2c, uint8_t data) 81 { 82 MAX7310State *s = MAX7310(i2c); 83 uint8_t diff; 84 int line; 85 86 if (s->len ++ > 1) { 87 #ifdef VERBOSE 88 printf("%s: message too long (%i bytes)\n", __func__, s->len); 89 #endif 90 return 1; 91 } 92 93 if (s->i2c_command_byte) { 94 s->command = data; 95 s->i2c_command_byte = 0; 96 return 0; 97 } 98 99 switch (s->command) { 100 case 0x01: /* Output port */ 101 for (diff = (data ^ s->level) & ~s->direction; diff; 102 diff &= ~(1 << line)) { 103 line = ctz32(diff); 104 if (s->handler[line]) 105 qemu_set_irq(s->handler[line], (data >> line) & 1); 106 } 107 s->level = (s->level & s->direction) | (data & ~s->direction); 108 break; 109 110 case 0x02: /* Polarity inversion */ 111 s->polarity = data; 112 break; 113 114 case 0x03: /* Configuration */ 115 s->level &= ~(s->direction ^ data); 116 s->direction = data; 117 break; 118 119 case 0x04: /* Timeout */ 120 s->status = data; 121 break; 122 123 case 0x00: /* Input port - ignore writes */ 124 break; 125 default: 126 qemu_log_mask(LOG_UNIMP, "%s: Unsupported register 0x02%" PRIx8 "\n", 127 __func__, s->command); 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 assert(line >= 0 && line < ARRAY_SIZE(s->handler)); 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