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 OBJECT_DECLARE_SIMPLE_TYPE(MAX7310State, MAX7310) 20 21 struct MAX7310State { 22 I2CSlave parent_obj; 23 24 int i2c_command_byte; 25 int len; 26 27 uint8_t level; 28 uint8_t direction; 29 uint8_t polarity; 30 uint8_t status; 31 uint8_t command; 32 qemu_irq handler[8]; 33 qemu_irq *gpio_in; 34 }; 35 36 static void max7310_reset(DeviceState *dev) 37 { 38 MAX7310State *s = MAX7310(dev); 39 40 s->level &= s->direction; 41 s->direction = 0xff; 42 s->polarity = 0xf0; 43 s->status = 0x01; 44 s->command = 0x00; 45 } 46 47 static uint8_t max7310_rx(I2CSlave *i2c) 48 { 49 MAX7310State *s = MAX7310(i2c); 50 51 switch (s->command) { 52 case 0x00: /* Input port */ 53 return s->level ^ s->polarity; 54 55 case 0x01: /* Output port */ 56 return s->level & ~s->direction; 57 58 case 0x02: /* Polarity inversion */ 59 return s->polarity; 60 61 case 0x03: /* Configuration */ 62 return s->direction; 63 64 case 0x04: /* Timeout */ 65 return s->status; 66 67 case 0xff: /* Reserved */ 68 return 0xff; 69 70 default: 71 qemu_log_mask(LOG_UNIMP, "%s: Unsupported register 0x02%" PRIx8 "\n", 72 __func__, s->command); 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 qemu_log_mask(LOG_UNIMP, "%s: Unsupported register 0x02%" PRIx8 "\n", 125 __func__, s->command); 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 assert(line >= 0 && line < ARRAY_SIZE(s->handler)); 175 176 if (level) 177 s->level |= s->direction & (1 << line); 178 else 179 s->level &= ~(s->direction & (1 << line)); 180 } 181 182 /* MAX7310 is SMBus-compatible (can be used with only SMBus protocols), 183 * but also accepts sequences that are not SMBus so return an I2C device. */ 184 static void max7310_realize(DeviceState *dev, Error **errp) 185 { 186 I2CSlave *i2c = I2C_SLAVE(dev); 187 MAX7310State *s = MAX7310(dev); 188 189 qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8); 190 qdev_init_gpio_out(&i2c->qdev, s->handler, 8); 191 } 192 193 static void max7310_class_init(ObjectClass *klass, void *data) 194 { 195 DeviceClass *dc = DEVICE_CLASS(klass); 196 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); 197 198 dc->realize = max7310_realize; 199 k->event = max7310_event; 200 k->recv = max7310_rx; 201 k->send = max7310_tx; 202 dc->reset = max7310_reset; 203 dc->vmsd = &vmstate_max7310; 204 } 205 206 static const TypeInfo max7310_info = { 207 .name = TYPE_MAX7310, 208 .parent = TYPE_I2C_SLAVE, 209 .instance_size = sizeof(MAX7310State), 210 .class_init = max7310_class_init, 211 }; 212 213 static void max7310_register_types(void) 214 { 215 type_register_static(&max7310_info); 216 } 217 218 type_init(max7310_register_types) 219