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/hw.h" 12 #include "hw/i2c/i2c.h" 13 #include "hw/hw.h" 14 #include "hw/irq.h" 15 #include "migration/vmstate.h" 16 #include "qemu/module.h" 17 #include "qom/object.h" 18 19 #define TYPE_MAX7310 "max7310" 20 typedef struct MAX7310State MAX7310State; 21 DECLARE_INSTANCE_CHECKER(MAX7310State, MAX7310, 22 TYPE_MAX7310) 23 24 struct MAX7310State { 25 I2CSlave parent_obj; 26 27 int i2c_command_byte; 28 int len; 29 30 uint8_t level; 31 uint8_t direction; 32 uint8_t polarity; 33 uint8_t status; 34 uint8_t command; 35 qemu_irq handler[8]; 36 qemu_irq *gpio_in; 37 }; 38 39 static void max7310_reset(DeviceState *dev) 40 { 41 MAX7310State *s = MAX7310(dev); 42 43 s->level &= s->direction; 44 s->direction = 0xff; 45 s->polarity = 0xf0; 46 s->status = 0x01; 47 s->command = 0x00; 48 } 49 50 static uint8_t max7310_rx(I2CSlave *i2c) 51 { 52 MAX7310State *s = MAX7310(i2c); 53 54 switch (s->command) { 55 case 0x00: /* Input port */ 56 return s->level ^ s->polarity; 57 58 case 0x01: /* Output port */ 59 return s->level & ~s->direction; 60 61 case 0x02: /* Polarity inversion */ 62 return s->polarity; 63 64 case 0x03: /* Configuration */ 65 return s->direction; 66 67 case 0x04: /* Timeout */ 68 return s->status; 69 70 case 0xff: /* Reserved */ 71 return 0xff; 72 73 default: 74 #ifdef VERBOSE 75 printf("%s: unknown register %02x\n", __func__, s->command); 76 #endif 77 break; 78 } 79 return 0xff; 80 } 81 82 static int max7310_tx(I2CSlave *i2c, uint8_t data) 83 { 84 MAX7310State *s = MAX7310(i2c); 85 uint8_t diff; 86 int line; 87 88 if (s->len ++ > 1) { 89 #ifdef VERBOSE 90 printf("%s: message too long (%i bytes)\n", __func__, s->len); 91 #endif 92 return 1; 93 } 94 95 if (s->i2c_command_byte) { 96 s->command = data; 97 s->i2c_command_byte = 0; 98 return 0; 99 } 100 101 switch (s->command) { 102 case 0x01: /* Output port */ 103 for (diff = (data ^ s->level) & ~s->direction; diff; 104 diff &= ~(1 << line)) { 105 line = ctz32(diff); 106 if (s->handler[line]) 107 qemu_set_irq(s->handler[line], (data >> line) & 1); 108 } 109 s->level = (s->level & s->direction) | (data & ~s->direction); 110 break; 111 112 case 0x02: /* Polarity inversion */ 113 s->polarity = data; 114 break; 115 116 case 0x03: /* Configuration */ 117 s->level &= ~(s->direction ^ data); 118 s->direction = data; 119 break; 120 121 case 0x04: /* Timeout */ 122 s->status = data; 123 break; 124 125 case 0x00: /* Input port - ignore writes */ 126 break; 127 default: 128 #ifdef VERBOSE 129 printf("%s: unknown register %02x\n", __func__, s->command); 130 #endif 131 return 1; 132 } 133 134 return 0; 135 } 136 137 static int max7310_event(I2CSlave *i2c, enum i2c_event event) 138 { 139 MAX7310State *s = MAX7310(i2c); 140 s->len = 0; 141 142 switch (event) { 143 case I2C_START_SEND: 144 s->i2c_command_byte = 1; 145 break; 146 case I2C_FINISH: 147 #ifdef VERBOSE 148 if (s->len == 1) 149 printf("%s: message too short (%i bytes)\n", __func__, s->len); 150 #endif 151 break; 152 default: 153 break; 154 } 155 156 return 0; 157 } 158 159 static const VMStateDescription vmstate_max7310 = { 160 .name = "max7310", 161 .version_id = 0, 162 .minimum_version_id = 0, 163 .fields = (VMStateField[]) { 164 VMSTATE_INT32(i2c_command_byte, MAX7310State), 165 VMSTATE_INT32(len, MAX7310State), 166 VMSTATE_UINT8(level, MAX7310State), 167 VMSTATE_UINT8(direction, MAX7310State), 168 VMSTATE_UINT8(polarity, MAX7310State), 169 VMSTATE_UINT8(status, MAX7310State), 170 VMSTATE_UINT8(command, MAX7310State), 171 VMSTATE_I2C_SLAVE(parent_obj, MAX7310State), 172 VMSTATE_END_OF_LIST() 173 } 174 }; 175 176 static void max7310_gpio_set(void *opaque, int line, int level) 177 { 178 MAX7310State *s = (MAX7310State *) opaque; 179 if (line >= ARRAY_SIZE(s->handler) || line < 0) 180 hw_error("bad GPIO line"); 181 182 if (level) 183 s->level |= s->direction & (1 << line); 184 else 185 s->level &= ~(s->direction & (1 << line)); 186 } 187 188 /* MAX7310 is SMBus-compatible (can be used with only SMBus protocols), 189 * but also accepts sequences that are not SMBus so return an I2C device. */ 190 static void max7310_realize(DeviceState *dev, Error **errp) 191 { 192 I2CSlave *i2c = I2C_SLAVE(dev); 193 MAX7310State *s = MAX7310(dev); 194 195 qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8); 196 qdev_init_gpio_out(&i2c->qdev, s->handler, 8); 197 } 198 199 static void max7310_class_init(ObjectClass *klass, void *data) 200 { 201 DeviceClass *dc = DEVICE_CLASS(klass); 202 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); 203 204 dc->realize = max7310_realize; 205 k->event = max7310_event; 206 k->recv = max7310_rx; 207 k->send = max7310_tx; 208 dc->reset = max7310_reset; 209 dc->vmsd = &vmstate_max7310; 210 } 211 212 static const TypeInfo max7310_info = { 213 .name = TYPE_MAX7310, 214 .parent = TYPE_I2C_SLAVE, 215 .instance_size = sizeof(MAX7310State), 216 .class_init = max7310_class_init, 217 }; 218 219 static void max7310_register_types(void) 220 { 221 type_register_static(&max7310_info); 222 } 223 224 type_init(max7310_register_types) 225