/* * 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; } 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", -1, 0, ads7846_save, ads7846_load, s); return s; }