[mirror_qemu.git] / hw / ads7846.c

/*
 * TI ADS7846 chip emulation.
 *
 * Copyright (c) 2006 Openedhand Ltd.
 * Written by Andrzej Zaborowski <balrog@zabor.org>
 *
 * This code is licensed under the GNU GPL v2.
 */

#include <vl.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	3680
#define X_AXIS_MIN	150
#define Y_AXIS_DMAX	3640
#define Y_AXIS_MIN	190

#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) {
        s->input[1] = ADS_YPOS(x, y);
        s->input[3] = ADS_Z1POS(x, y);
        s->input[4] = ADS_Z2POS(x, y);
        s->input[5] = ADS_XPOS(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;
}
Commit	Line	Data
fd5a3b33 AZ	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
aa941b94	107	ads7846_int_update(s);
fd5a3b33 AZ	108	}
	109	}
	110
aa941b94 AZ	111	static void ads7846_save(QEMUFile f, void opaque)
	112	{
	113	struct ads7846_state_s s = (struct ads7846_state_s ) opaque;
	114	int i;
	115
	116	for (i = 0; i < 8; i ++)
	117	qemu_put_be32(f, s->input[i]);
	118	qemu_put_be32(f, s->noise);
	119	qemu_put_be32(f, s->cycle);
	120	qemu_put_be32(f, s->output);
	121	}
	122
	123	static int ads7846_load(QEMUFile f, void opaque, int version_id)
	124	{
	125	struct ads7846_state_s s = (struct ads7846_state_s ) opaque;
	126	int i;
	127
	128	for (i = 0; i < 8; i ++)
	129	s->input[i] = qemu_get_be32(f);
	130	s->noise = qemu_get_be32(f);
	131	s->cycle = qemu_get_be32(f);
	132	s->output = qemu_get_be32(f);
	133
	134	s->pressure = 0;
	135	ads7846_int_update(s);
	136
	137	return 0;
	138	}
	139
	140	static int ads7846_iid = 0;
	141
fd5a3b33 AZ	142	struct ads7846_state_s *ads7846_init(qemu_irq penirq)
	143	{
	144	struct ads7846_state_s *s;
	145	s = (struct ads7846_state_s *)
	146	qemu_mallocz(sizeof(struct ads7846_state_s));
	147	memset(s, 0, sizeof(struct ads7846_state_s));
	148
	149	s->interrupt = penirq;
	150
	151	s->input[0] = ADS_TEMP0; /* TEMP0 */
	152	s->input[2] = ADS_VBAT; /* VBAT */
	153	s->input[6] = ADS_VAUX; /* VAUX */
	154	s->input[7] = ADS_TEMP1; /* TEMP1 */
	155
	156	/* We want absolute coordinates */
	157	qemu_add_mouse_event_handler(ads7846_ts_event, s, 1,
	158	"QEMU ADS7846-driven Touchscreen");
	159
	160	ads7846_int_update(s);
aa941b94 AZ	161
	162	register_savevm("ads7846", ads7846_iid ++, 0,
	163	ads7846_save, ads7846_load, s);
	164
fd5a3b33 AZ	165	return s;
fd5a3b33 AZ	166	}