1 | /* |
2 | * TI ADS7846 / TSC2046 chip emulation. |
3 | * |
4 | * Copyright (c) 2006 Openedhand Ltd. |
5 | * Written by Andrzej Zaborowski <balrog@zabor.org> |
6 | * |
7 | * This code is licensed under the GNU GPL v2. |
8 | * |
9 | * Contributions after 2012-01-13 are licensed under the terms of the |
10 | * GNU GPL, version 2 or (at your option) any later version. |
11 | */ |
12 | |
13 | #include "qemu/osdep.h" |
14 | #include "hw/irq.h" |
15 | #include "hw/ssi/ssi.h" |
16 | #include "migration/vmstate.h" |
17 | #include "qemu/module.h" |
18 | #include "ui/console.h" |
19 | |
20 | typedef struct { |
21 | SSISlave ssidev; |
22 | qemu_irq interrupt; |
23 | |
24 | int input[8]; |
25 | int pressure; |
26 | int noise; |
27 | |
28 | int cycle; |
29 | int output; |
30 | } ADS7846State; |
31 | |
32 | /* Control-byte bitfields */ |
33 | #define CB_PD0 (1 << 0) |
34 | #define CB_PD1 (1 << 1) |
35 | #define CB_SER (1 << 2) |
36 | #define CB_MODE (1 << 3) |
37 | #define CB_A0 (1 << 4) |
38 | #define CB_A1 (1 << 5) |
39 | #define CB_A2 (1 << 6) |
40 | #define CB_START (1 << 7) |
41 | |
42 | #define X_AXIS_DMAX 3470 |
43 | #define X_AXIS_MIN 290 |
44 | #define Y_AXIS_DMAX 3450 |
45 | #define Y_AXIS_MIN 200 |
46 | |
47 | #define ADS_VBAT 2000 |
48 | #define ADS_VAUX 2000 |
49 | #define ADS_TEMP0 2000 |
50 | #define ADS_TEMP1 3000 |
51 | #define ADS_XPOS(x, y) (X_AXIS_MIN + ((X_AXIS_DMAX * (x)) >> 15)) |
52 | #define ADS_YPOS(x, y) (Y_AXIS_MIN + ((Y_AXIS_DMAX * (y)) >> 15)) |
53 | #define ADS_Z1POS(x, y) 600 |
54 | #define ADS_Z2POS(x, y) (600 + 6000 / ADS_XPOS(x, y)) |
55 | |
56 | static void ads7846_int_update(ADS7846State *s) |
57 | { |
58 | if (s->interrupt) |
59 | qemu_set_irq(s->interrupt, s->pressure == 0); |
60 | } |
61 | |
62 | static uint32_t ads7846_transfer(SSISlave *dev, uint32_t value) |
63 | { |
64 | ADS7846State *s = FROM_SSI_SLAVE(ADS7846State, dev); |
65 | |
66 | switch (s->cycle ++) { |
67 | case 0: |
68 | if (!(value & CB_START)) { |
69 | s->cycle = 0; |
70 | break; |
71 | } |
72 | |
73 | s->output = s->input[(value >> 4) & 7]; |
74 | |
75 | /* Imitate the ADC noise, some drivers expect this. */ |
76 | s->noise = (s->noise + 3) & 7; |
77 | switch ((value >> 4) & 7) { |
78 | case 1: s->output += s->noise ^ 2; break; |
79 | case 3: s->output += s->noise ^ 0; break; |
80 | case 4: s->output += s->noise ^ 7; break; |
81 | case 5: s->output += s->noise ^ 5; break; |
82 | } |
83 | |
84 | if (value & CB_MODE) |
85 | s->output >>= 4; /* 8 bits instead of 12 */ |
86 | |
87 | break; |
88 | case 1: |
89 | s->cycle = 0; |
90 | break; |
91 | } |
92 | return s->output; |
93 | } |
94 | |
95 | static void ads7846_ts_event(void *opaque, |
96 | int x, int y, int z, int buttons_state) |
97 | { |
98 | ADS7846State *s = opaque; |
99 | |
100 | if (buttons_state) { |
101 | x = 0x7fff - x; |
102 | s->input[1] = ADS_XPOS(x, y); |
103 | s->input[3] = ADS_Z1POS(x, y); |
104 | s->input[4] = ADS_Z2POS(x, y); |
105 | s->input[5] = ADS_YPOS(x, y); |
106 | } |
107 | |
108 | if (s->pressure == !buttons_state) { |
109 | s->pressure = !!buttons_state; |
110 | |
111 | ads7846_int_update(s); |
112 | } |
113 | } |
114 | |
115 | static int ads7856_post_load(void *opaque, int version_id) |
116 | { |
117 | ADS7846State *s = opaque; |
118 | |
119 | s->pressure = 0; |
120 | ads7846_int_update(s); |
121 | return 0; |
122 | } |
123 | |
124 | static const VMStateDescription vmstate_ads7846 = { |
125 | .name = "ads7846" , |
126 | .version_id = 1, |
127 | .minimum_version_id = 1, |
128 | .post_load = ads7856_post_load, |
129 | .fields = (VMStateField[]) { |
130 | VMSTATE_SSI_SLAVE(ssidev, ADS7846State), |
131 | VMSTATE_INT32_ARRAY(input, ADS7846State, 8), |
132 | VMSTATE_INT32(noise, ADS7846State), |
133 | VMSTATE_INT32(cycle, ADS7846State), |
134 | VMSTATE_INT32(output, ADS7846State), |
135 | VMSTATE_END_OF_LIST() |
136 | } |
137 | }; |
138 | |
139 | static void ads7846_realize(SSISlave *d, Error **errp) |
140 | { |
141 | DeviceState *dev = DEVICE(d); |
142 | ADS7846State *s = FROM_SSI_SLAVE(ADS7846State, d); |
143 | |
144 | qdev_init_gpio_out(dev, &s->interrupt, 1); |
145 | |
146 | s->input[0] = ADS_TEMP0; /* TEMP0 */ |
147 | s->input[2] = ADS_VBAT; /* VBAT */ |
148 | s->input[6] = ADS_VAUX; /* VAUX */ |
149 | s->input[7] = ADS_TEMP1; /* TEMP1 */ |
150 | |
151 | /* We want absolute coordinates */ |
152 | qemu_add_mouse_event_handler(ads7846_ts_event, s, 1, |
153 | "QEMU ADS7846-driven Touchscreen" ); |
154 | |
155 | ads7846_int_update(s); |
156 | |
157 | vmstate_register(NULL, -1, &vmstate_ads7846, s); |
158 | } |
159 | |
160 | static void ads7846_class_init(ObjectClass *klass, void *data) |
161 | { |
162 | SSISlaveClass *k = SSI_SLAVE_CLASS(klass); |
163 | |
164 | k->realize = ads7846_realize; |
165 | k->transfer = ads7846_transfer; |
166 | } |
167 | |
168 | static const TypeInfo ads7846_info = { |
169 | .name = "ads7846" , |
170 | .parent = TYPE_SSI_SLAVE, |
171 | .instance_size = sizeof(ADS7846State), |
172 | .class_init = ads7846_class_init, |
173 | }; |
174 | |
175 | static void ads7846_register_types(void) |
176 | { |
177 | type_register_static(&ads7846_info); |
178 | } |
179 | |
180 | type_init(ads7846_register_types) |
181 | |