diff options
| -rw-r--r-- | hw/ads7846.c | 131 | ||||
| -rw-r--r-- | vl.h | 6 |
2 files changed, 137 insertions, 0 deletions
diff --git a/hw/ads7846.c b/hw/ads7846.c new file mode 100644 index 0000000000..d63a915419 --- /dev/null +++ b/hw/ads7846.c @@ -0,0 +1,131 @@ +/* + * 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); + } +} + +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); + return s; +} @@ -1500,6 +1500,12 @@ uint8_t nand_getio(struct nand_flash_s *s); #include "ecc.h" +/* ads7846.c */ +struct ads7846_state_s; +uint32_t ads7846_read(void *opaque); +void ads7846_write(void *opaque, uint32_t value); +struct ads7846_state_s *ads7846_init(qemu_irq penirq); + /* PCMCIA/Cardbus */ struct pcmcia_socket_s { |