xref: /illumos-kvm-cmd/hw/max7310.c (revision 68396ea9)
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 "i2c.h"
11 
12 typedef struct {
13     i2c_slave i2c;
14     int i2c_command_byte;
15     int len;
16 
17     uint8_t level;
18     uint8_t direction;
19     uint8_t polarity;
20     uint8_t status;
21     uint8_t command;
22     qemu_irq handler[8];
23     qemu_irq *gpio_in;
24 } MAX7310State;
25 
max7310_reset(i2c_slave * i2c)26 void max7310_reset(i2c_slave *i2c)
27 {
28     MAX7310State *s = (MAX7310State *) i2c;
29     s->level &= s->direction;
30     s->direction = 0xff;
31     s->polarity = 0xf0;
32     s->status = 0x01;
33     s->command = 0x00;
34 }
35 
max7310_rx(i2c_slave * i2c)36 static int max7310_rx(i2c_slave *i2c)
37 {
38     MAX7310State *s = (MAX7310State *) i2c;
39 
40     switch (s->command) {
41     case 0x00:	/* Input port */
42         return s->level ^ s->polarity;
43         break;
44 
45     case 0x01:	/* Output port */
46         return s->level & ~s->direction;
47         break;
48 
49     case 0x02:	/* Polarity inversion */
50         return s->polarity;
51 
52     case 0x03:	/* Configuration */
53         return s->direction;
54 
55     case 0x04:	/* Timeout */
56         return s->status;
57         break;
58 
59     case 0xff:	/* Reserved */
60         return 0xff;
61 
62     default:
63 #ifdef VERBOSE
64         printf("%s: unknown register %02x\n", __FUNCTION__, s->command);
65 #endif
66         break;
67     }
68     return 0xff;
69 }
70 
max7310_tx(i2c_slave * i2c,uint8_t data)71 static int max7310_tx(i2c_slave *i2c, uint8_t data)
72 {
73     MAX7310State *s = (MAX7310State *) i2c;
74     uint8_t diff;
75     int line;
76 
77     if (s->len ++ > 1) {
78 #ifdef VERBOSE
79         printf("%s: message too long (%i bytes)\n", __FUNCTION__, s->len);
80 #endif
81         return 1;
82     }
83 
84     if (s->i2c_command_byte) {
85         s->command = data;
86         s->i2c_command_byte = 0;
87         return 0;
88     }
89 
90     switch (s->command) {
91     case 0x01:	/* Output port */
92         for (diff = (data ^ s->level) & ~s->direction; diff;
93                         diff &= ~(1 << line)) {
94             line = ffs(diff) - 1;
95             if (s->handler[line])
96                 qemu_set_irq(s->handler[line], (data >> line) & 1);
97         }
98         s->level = (s->level & s->direction) | (data & ~s->direction);
99         break;
100 
101     case 0x02:	/* Polarity inversion */
102         s->polarity = data;
103         break;
104 
105     case 0x03:	/* Configuration */
106         s->level &= ~(s->direction ^ data);
107         s->direction = data;
108         break;
109 
110     case 0x04:	/* Timeout */
111         s->status = data;
112         break;
113 
114     case 0x00:	/* Input port - ignore writes */
115 	break;
116     default:
117 #ifdef VERBOSE
118         printf("%s: unknown register %02x\n", __FUNCTION__, s->command);
119 #endif
120         return 1;
121     }
122 
123     return 0;
124 }
125 
max7310_event(i2c_slave * i2c,enum i2c_event event)126 static void max7310_event(i2c_slave *i2c, enum i2c_event event)
127 {
128     MAX7310State *s = (MAX7310State *) i2c;
129     s->len = 0;
130 
131     switch (event) {
132     case I2C_START_SEND:
133         s->i2c_command_byte = 1;
134         break;
135     case I2C_FINISH:
136 #ifdef VERBOSE
137         if (s->len == 1)
138             printf("%s: message too short (%i bytes)\n", __FUNCTION__, s->len);
139 #endif
140         break;
141     default:
142         break;
143     }
144 }
145 
146 static const VMStateDescription vmstate_max7310 = {
147     .name = "max7310",
148     .version_id = 0,
149     .minimum_version_id = 0,
150     .minimum_version_id_old = 0,
151     .fields      = (VMStateField []) {
152         VMSTATE_INT32(i2c_command_byte, MAX7310State),
153         VMSTATE_INT32(len, MAX7310State),
154         VMSTATE_UINT8(level, MAX7310State),
155         VMSTATE_UINT8(direction, MAX7310State),
156         VMSTATE_UINT8(polarity, MAX7310State),
157         VMSTATE_UINT8(status, MAX7310State),
158         VMSTATE_UINT8(command, MAX7310State),
159         VMSTATE_I2C_SLAVE(i2c, MAX7310State),
160         VMSTATE_END_OF_LIST()
161     }
162 };
163 
max7310_gpio_set(void * opaque,int line,int level)164 static void max7310_gpio_set(void *opaque, int line, int level)
165 {
166     MAX7310State *s = (MAX7310State *) opaque;
167     if (line >= ARRAY_SIZE(s->handler) || line  < 0)
168         hw_error("bad GPIO line");
169 
170     if (level)
171         s->level |= s->direction & (1 << line);
172     else
173         s->level &= ~(s->direction & (1 << line));
174 }
175 
176 /* MAX7310 is SMBus-compatible (can be used with only SMBus protocols),
177  * but also accepts sequences that are not SMBus so return an I2C device.  */
max7310_init(i2c_slave * i2c)178 static int max7310_init(i2c_slave *i2c)
179 {
180     MAX7310State *s = FROM_I2C_SLAVE(MAX7310State, i2c);
181 
182     s->gpio_in = qemu_allocate_irqs(max7310_gpio_set, s,
183                     ARRAY_SIZE(s->handler));
184 
185     max7310_reset(&s->i2c);
186 
187     return 0;
188 }
189 
max7310_gpio_in_get(i2c_slave * i2c)190 qemu_irq *max7310_gpio_in_get(i2c_slave *i2c)
191 {
192     MAX7310State *s = (MAX7310State *) i2c;
193     return s->gpio_in;
194 }
195 
max7310_gpio_out_set(i2c_slave * i2c,int line,qemu_irq handler)196 void max7310_gpio_out_set(i2c_slave *i2c, int line, qemu_irq handler)
197 {
198     MAX7310State *s = (MAX7310State *) i2c;
199     if (line >= ARRAY_SIZE(s->handler) || line  < 0)
200         hw_error("bad GPIO line");
201 
202     s->handler[line] = handler;
203 }
204 
205 static I2CSlaveInfo max7310_info = {
206     .qdev.name = "max7310",
207     .qdev.size = sizeof(MAX7310State),
208     .qdev.vmsd = &vmstate_max7310,
209     .init = max7310_init,
210     .event = max7310_event,
211     .recv = max7310_rx,
212     .send = max7310_tx
213 };
214 
max7310_register_devices(void)215 static void max7310_register_devices(void)
216 {
217     i2c_register_slave(&max7310_info);
218 }
219 
220 device_init(max7310_register_devices)
221