diff options
Diffstat (limited to 'hw/display/ads7846.c')
| -rw-r--r-- | hw/display/ads7846.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/hw/display/ads7846.c b/hw/display/ads7846.c new file mode 100644 index 0000000000..5da3dc5b2c --- /dev/null +++ b/hw/display/ads7846.c @@ -0,0 +1,177 @@ +/* + * 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. + * + * Contributions after 2012-01-13 are licensed under the terms of the + * GNU GPL, version 2 or (at your option) any later version. + */ + +#include "hw/ssi.h" +#include "ui/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 = 1, + .minimum_version_id = 1, + .minimum_version_id_old = 1, + .post_load = ads7856_post_load, + .fields = (VMStateField[]) { + VMSTATE_SSI_SLAVE(ssidev, ADS7846State), + 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 const TypeInfo ads7846_info = { + .name = "ads7846", + .parent = TYPE_SSI_SLAVE, + .instance_size = sizeof(ADS7846State), + .class_init = ads7846_class_init, +}; + +static void ads7846_register_types(void) +{ + type_register_static(&ads7846_info); +} + +type_init(ads7846_register_types) |