2 * TI ADS7846 / TSC2046 chip emulation.
4 * Copyright (c) 2006 Openedhand Ltd.
5 * Written by Andrzej Zaborowski <balrog@zabor.org>
7 * This code is licensed under the GNU GPL v2.
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.
13 #include "qemu/osdep.h"
14 #include "hw/ssi/ssi.h"
15 #include "qemu/module.h"
16 #include "ui/console.h"
30 /* Control-byte bitfields */
31 #define CB_PD0 (1 << 0)
32 #define CB_PD1 (1 << 1)
33 #define CB_SER (1 << 2)
34 #define CB_MODE (1 << 3)
35 #define CB_A0 (1 << 4)
36 #define CB_A1 (1 << 5)
37 #define CB_A2 (1 << 6)
38 #define CB_START (1 << 7)
40 #define X_AXIS_DMAX 3470
41 #define X_AXIS_MIN 290
42 #define Y_AXIS_DMAX 3450
43 #define Y_AXIS_MIN 200
47 #define ADS_TEMP0 2000
48 #define ADS_TEMP1 3000
49 #define ADS_XPOS(x, y) (X_AXIS_MIN + ((X_AXIS_DMAX * (x)) >> 15))
50 #define ADS_YPOS(x, y) (Y_AXIS_MIN + ((Y_AXIS_DMAX * (y)) >> 15))
51 #define ADS_Z1POS(x, y) 600
52 #define ADS_Z2POS(x, y) (600 + 6000 / ADS_XPOS(x, y))
54 static void ads7846_int_update(ADS7846State
*s
)
57 qemu_set_irq(s
->interrupt
, s
->pressure
== 0);
60 static uint32_t ads7846_transfer(SSISlave
*dev
, uint32_t value
)
62 ADS7846State
*s
= FROM_SSI_SLAVE(ADS7846State
, dev
);
64 switch (s
->cycle
++) {
66 if (!(value
& CB_START
)) {
71 s
->output
= s
->input
[(value
>> 4) & 7];
73 /* Imitate the ADC noise, some drivers expect this. */
74 s
->noise
= (s
->noise
+ 3) & 7;
75 switch ((value
>> 4) & 7) {
76 case 1: s
->output
+= s
->noise
^ 2; break;
77 case 3: s
->output
+= s
->noise
^ 0; break;
78 case 4: s
->output
+= s
->noise
^ 7; break;
79 case 5: s
->output
+= s
->noise
^ 5; break;
83 s
->output
>>= 4; /* 8 bits instead of 12 */
93 static void ads7846_ts_event(void *opaque
,
94 int x
, int y
, int z
, int buttons_state
)
96 ADS7846State
*s
= opaque
;
100 s
->input
[1] = ADS_XPOS(x
, y
);
101 s
->input
[3] = ADS_Z1POS(x
, y
);
102 s
->input
[4] = ADS_Z2POS(x
, y
);
103 s
->input
[5] = ADS_YPOS(x
, y
);
106 if (s
->pressure
== !buttons_state
) {
107 s
->pressure
= !!buttons_state
;
109 ads7846_int_update(s
);
113 static int ads7856_post_load(void *opaque
, int version_id
)
115 ADS7846State
*s
= opaque
;
118 ads7846_int_update(s
);
122 static const VMStateDescription vmstate_ads7846
= {
125 .minimum_version_id
= 1,
126 .post_load
= ads7856_post_load
,
127 .fields
= (VMStateField
[]) {
128 VMSTATE_SSI_SLAVE(ssidev
, ADS7846State
),
129 VMSTATE_INT32_ARRAY(input
, ADS7846State
, 8),
130 VMSTATE_INT32(noise
, ADS7846State
),
131 VMSTATE_INT32(cycle
, ADS7846State
),
132 VMSTATE_INT32(output
, ADS7846State
),
133 VMSTATE_END_OF_LIST()
137 static void ads7846_realize(SSISlave
*d
, Error
**errp
)
139 DeviceState
*dev
= DEVICE(d
);
140 ADS7846State
*s
= FROM_SSI_SLAVE(ADS7846State
, d
);
142 qdev_init_gpio_out(dev
, &s
->interrupt
, 1);
144 s
->input
[0] = ADS_TEMP0
; /* TEMP0 */
145 s
->input
[2] = ADS_VBAT
; /* VBAT */
146 s
->input
[6] = ADS_VAUX
; /* VAUX */
147 s
->input
[7] = ADS_TEMP1
; /* TEMP1 */
149 /* We want absolute coordinates */
150 qemu_add_mouse_event_handler(ads7846_ts_event
, s
, 1,
151 "QEMU ADS7846-driven Touchscreen");
153 ads7846_int_update(s
);
155 vmstate_register(NULL
, -1, &vmstate_ads7846
, s
);
158 static void ads7846_class_init(ObjectClass
*klass
, void *data
)
160 SSISlaveClass
*k
= SSI_SLAVE_CLASS(klass
);
162 k
->realize
= ads7846_realize
;
163 k
->transfer
= ads7846_transfer
;
166 static const TypeInfo ads7846_info
= {
168 .parent
= TYPE_SSI_SLAVE
,
169 .instance_size
= sizeof(ADS7846State
),
170 .class_init
= ads7846_class_init
,
173 static void ads7846_register_types(void)
175 type_register_static(&ads7846_info
);
178 type_init(ads7846_register_types
)