/* * TI ADS7846 / TSC2046 chip emulation. * * Copyright (c) 2006 Openedhand Ltd. * Written by Andrzej Zaborowski <balrog@zabor.org> * * This code is licensed under the GNU GPL v2. */#include "hw.h"#include "devices.h"#include "console.h"struct ads7846_state_s {    qemu_irq interrupt;    int input[8];    int pressure;    int noise;    int cycle;    int output;};/* Control-byte bitfields */#define CB_PD0		(1 << 0)#define CB_PD1		(1 << 1)#define CB_SER		(1 << 2)#define CB_MODE		(1 << 3)#define CB_A0		(1 << 4)#define CB_A1		(1 << 5)#define CB_A2		(1 << 6)#define CB_START	(1 << 7)#define X_AXIS_DMAX	3470#define X_AXIS_MIN	290#define Y_AXIS_DMAX	3450#define Y_AXIS_MIN	200#define ADS_VBAT	2000#define ADS_VAUX	2000#define ADS_TEMP0	2000#define ADS_TEMP1	3000#define ADS_XPOS(x, y)	(X_AXIS_MIN + ((X_AXIS_DMAX * (x)) >> 15))#define ADS_YPOS(x, y)	(Y_AXIS_MIN + ((Y_AXIS_DMAX * (y)) >> 15))#define ADS_Z1POS(x, y)	600#define ADS_Z2POS(x, y)	(600 + 6000 / ADS_XPOS(x, y))static void ads7846_int_update(struct ads7846_state_s *s){    if (s->interrupt)        qemu_set_irq(s->interrupt, s->pressure == 0);}uint32_t ads7846_read(void *opaque){    struct ads7846_state_s *s = (struct ads7846_state_s *) opaque;    return s->output;}void ads7846_write(void *opaque, uint32_t value){    struct ads7846_state_s *s = (struct ads7846_state_s *) opaque;    switch (s->cycle ++) {    case 0:        if (!(value & CB_START)) {            s->cycle = 0;            break;        }        s->output = s->input[(value >> 4) & 7];        /* Imitate the ADC noise, some drivers expect this.  */        s->noise = (s->noise + 3) & 7;        switch ((value >> 4) & 7) {        case 1: s->output += s->noise ^ 2; break;        case 3: s->output += s->noise ^ 0; break;        case 4: s->output += s->noise ^ 7; break;        case 5: s->output += s->noise ^ 5; break;        }        if (value & CB_MODE)            s->output >>= 4;	/* 8 bits instead of 12 */        break;    case 1:        s->cycle = 0;        break;    }}static void ads7846_ts_event(void *opaque,                int x, int y, int z, int buttons_state){    struct ads7846_state_s *s = opaque;    if (buttons_state) {        x = 0x7fff - x;        s->input[1] = ADS_XPOS(x, y);        s->input[3] = ADS_Z1POS(x, y);        s->input[4] = ADS_Z2POS(x, y);        s->input[5] = ADS_YPOS(x, y);    }    if (s->pressure == !buttons_state) {        s->pressure = !!buttons_state;        ads7846_int_update(s);    }}static void ads7846_save(QEMUFile *f, void *opaque){    struct ads7846_state_s *s = (struct ads7846_state_s *) opaque;    int i;    for (i = 0; i < 8; i ++)        qemu_put_be32(f, s->input[i]);    qemu_put_be32(f, s->noise);    qemu_put_be32(f, s->cycle);    qemu_put_be32(f, s->output);}static int ads7846_load(QEMUFile *f, void *opaque, int version_id){    struct ads7846_state_s *s = (struct ads7846_state_s *) opaque;    int i;    for (i = 0; i < 8; i ++)        s->input[i] = qemu_get_be32(f);    s->noise = qemu_get_be32(f);    s->cycle = qemu_get_be32(f);    s->output = qemu_get_be32(f);    s->pressure = 0;    ads7846_int_update(s);    return 0;}static int ads7846_iid = 0;struct ads7846_state_s *ads7846_init(qemu_irq penirq){    struct ads7846_state_s *s;    s = (struct ads7846_state_s *)            qemu_mallocz(sizeof(struct ads7846_state_s));    memset(s, 0, sizeof(struct ads7846_state_s));    s->interrupt = penirq;    s->input[0] = ADS_TEMP0;	/* TEMP0 */    s->input[2] = ADS_VBAT;	/* VBAT */    s->input[6] = ADS_VAUX;	/* VAUX */    s->input[7] = ADS_TEMP1;	/* TEMP1 */    /* We want absolute coordinates */    qemu_add_mouse_event_handler(ads7846_ts_event, s, 1,                    "QEMU ADS7846-driven Touchscreen");    ads7846_int_update(s);    register_savevm("ads7846", ads7846_iid ++, 0,                    ads7846_save, ads7846_load, s);    return s;}