gwj / at91sam9263 · Commits

Commit fd5a3b33d1f19b4859a8c528097abdbc4463e7e0

Authored by balrog
1 parent 3e3d5815

Texas Instruments ADS7846 ADC chip. 


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2754 c046a42c-6fe2-441c-8c8c-71466251a162
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hw/ads7846.c 0 → 100644
  View file @fd5a3b3
  1 +/*
  2 + * TI ADS7846 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 +
  10 +#include <vl.h>
  11 +
  12 +struct ads7846_state_s {
  13 + qemu_irq interrupt;
  14 +
  15 + int input[8];
  16 + int pressure;
  17 + int noise;
  18 +
  19 + int cycle;
  20 + int output;
  21 +};
  22 +
  23 +/* Control-byte bitfields */
  24 +#define CB_PD0 (1 << 0)
  25 +#define CB_PD1 (1 << 1)
  26 +#define CB_SER (1 << 2)
  27 +#define CB_MODE (1 << 3)
  28 +#define CB_A0 (1 << 4)
  29 +#define CB_A1 (1 << 5)
  30 +#define CB_A2 (1 << 6)
  31 +#define CB_START (1 << 7)
  32 +
  33 +#define X_AXIS_DMAX 3680
  34 +#define X_AXIS_MIN 150
  35 +#define Y_AXIS_DMAX 3640
  36 +#define Y_AXIS_MIN 190
  37 +
  38 +#define ADS_VBAT 2000
  39 +#define ADS_VAUX 2000
  40 +#define ADS_TEMP0 2000
  41 +#define ADS_TEMP1 3000
  42 +#define ADS_XPOS(x, y) (X_AXIS_MIN + ((X_AXIS_DMAX * (x)) >> 15))
  43 +#define ADS_YPOS(x, y) (Y_AXIS_MIN + ((Y_AXIS_DMAX * (y)) >> 15))
  44 +#define ADS_Z1POS(x, y) 600
  45 +#define ADS_Z2POS(x, y) (600 + 6000 / ADS_XPOS(x, y))
  46 +
  47 +static void ads7846_int_update(struct ads7846_state_s *s)
  48 +{
  49 + if (s->interrupt)
  50 + qemu_set_irq(s->interrupt, s->pressure == 0);
  51 +}
  52 +
  53 +uint32_t ads7846_read(void *opaque)
  54 +{
  55 + struct ads7846_state_s *s = (struct ads7846_state_s *) opaque;
  56 +
  57 + return s->output;
  58 +}
  59 +
  60 +void ads7846_write(void *opaque, uint32_t value)
  61 +{
  62 + struct ads7846_state_s *s = (struct ads7846_state_s *) opaque;
  63 +
  64 + switch (s->cycle ++) {
  65 + case 0:
  66 + if (!(value & CB_START)) {
  67 + s->cycle = 0;
  68 + break;
  69 + }
  70 +
  71 + s->output = s->input[(value >> 4) & 7];
  72 +
  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;
  80 + }
  81 +
  82 + if (value & CB_MODE)
  83 + s->output >>= 4; /* 8 bits instead of 12 */
  84 +
  85 + break;
  86 + case 1:
  87 + s->cycle = 0;
  88 + break;
  89 + }
  90 +}
  91 +
  92 +static void ads7846_ts_event(void *opaque,
  93 + int x, int y, int z, int buttons_state)
  94 +{
  95 + struct ads7846_state_s *s = opaque;
  96 +
  97 + if (buttons_state) {
  98 + s->input[1] = ADS_YPOS(x, y);
  99 + s->input[3] = ADS_Z1POS(x, y);
  100 + s->input[4] = ADS_Z2POS(x, y);
  101 + s->input[5] = ADS_XPOS(x, y);
  102 + }
  103 +
  104 + if (s->pressure == !buttons_state) {
  105 + s->pressure = !!buttons_state;
  106 +
  107 + ads7846_int_update(s);
  108 + }
  109 +}
  110 +
  111 +struct ads7846_state_s *ads7846_init(qemu_irq penirq)
  112 +{
  113 + struct ads7846_state_s *s;
  114 + s = (struct ads7846_state_s *)
  115 + qemu_mallocz(sizeof(struct ads7846_state_s));
  116 + memset(s, 0, sizeof(struct ads7846_state_s));
  117 +
  118 + s->interrupt = penirq;
  119 +
  120 + s->input[0] = ADS_TEMP0; /* TEMP0 */
  121 + s->input[2] = ADS_VBAT; /* VBAT */
  122 + s->input[6] = ADS_VAUX; /* VAUX */
  123 + s->input[7] = ADS_TEMP1; /* TEMP1 */
  124 +
  125 + /* We want absolute coordinates */
  126 + qemu_add_mouse_event_handler(ads7846_ts_event, s, 1,
  127 + "QEMU ADS7846-driven Touchscreen");
  128 +
  129 + ads7846_int_update(s);
  130 + return s;
  131 +}
... ...
... ... @@ -1500,6 +1500,12 @@ uint8_t nand_getio(struct nand_flash_s *s);
1500 1500  
1501 1501 #include "ecc.h"
1502 1502  
  1503 +/* ads7846.c */
  1504 +struct ads7846_state_s;
  1505 +uint32_t ads7846_read(void *opaque);
  1506 +void ads7846_write(void *opaque, uint32_t value);
  1507 +struct ads7846_state_s *ads7846_init(qemu_irq penirq);
  1508 +
1503 1509 /* PCMCIA/Cardbus */
1504 1510  
1505 1511 struct pcmcia_socket_s {
... ...