/* * TI ADS7846 / TSC2046 chip emulation. * * Copyright (c) 2006 Openedhand Ltd. * Written by Andrzej Zaborowski * * This code is licensed under the GNU GPL v2. * * Contributions after 2012-01-13 are licensed under the terms of the * GNU GPL, version 2 or (at your option) any later version. */ #include "ssi.h" #include "console.h" typedef struct { SSISlave ssidev; qemu_irq interrupt; int input[8]; int pressure; int noise; int cycle; int output; } ADS7846State; /* 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(ADS7846State *s) { if (s->interrupt) qemu_set_irq(s->interrupt, s->pressure == 0); } static uint32_t ads7846_transfer(SSISlave *dev, uint32_t value) { ADS7846State *s = FROM_SSI_SLAVE(ADS7846State, dev); 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; } return s->output; } static void ads7846_ts_event(void *opaque, int x, int y, int z, int buttons_state) { ADS7846State *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 int ads7856_post_load(void *opaque, int version_id) { ADS7846State *s = opaque; s->pressure = 0; ads7846_int_update(s); return 0; } static const VMStateDescription vmstate_ads7846 = { .name = "ads7846", .version_id = 0, .minimum_version_id = 0, .minimum_version_id_old = 0, .post_load = ads7856_post_load, .fields = (VMStateField[]) { VMSTATE_INT32_ARRAY(input, ADS7846State, 8), VMSTATE_INT32(noise, ADS7846State), VMSTATE_INT32(cycle, ADS7846State), VMSTATE_INT32(output, ADS7846State), VMSTATE_END_OF_LIST() } }; static int ads7846_init(SSISlave *dev) { ADS7846State *s = FROM_SSI_SLAVE(ADS7846State, dev); qdev_init_gpio_out(&dev->qdev, &s->interrupt, 1); 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); vmstate_register(NULL, -1, &vmstate_ads7846, s); return 0; } static void ads7846_class_init(ObjectClass *klass, void *data) { SSISlaveClass *k = SSI_SLAVE_CLASS(klass); k->init = ads7846_init; k->transfer = ads7846_transfer; } static TypeInfo ads7846_info = { .name = "ads7846", .parent = TYPE_SSI_SLAVE, .instance_size = sizeof(ADS7846State), .class_init = ads7846_class_init, }; static void ads7846_register_devices(void) { type_register_static(&ads7846_info); } device_init(ads7846_register_devices)