diff options
Diffstat (limited to 'core/drivers/ps2mouse.c')
| -rw-r--r-- | core/drivers/ps2mouse.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/core/drivers/ps2mouse.c b/core/drivers/ps2mouse.c new file mode 100644 index 0000000..893b247 --- /dev/null +++ b/core/drivers/ps2mouse.c @@ -0,0 +1,160 @@ +/* + * Copyright (c) 2016, Linaro Limited + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <types_ext.h> +#include <drivers/ps2mouse.h> +#include <drivers/serial.h> +#include <string.h> +#include <keep.h> +#include <trace.h> + +#define PS2_CMD_RESET 0xff +#define PS2_CMD_ACK 0xfa +#define PS2_CMD_ENABLE_DATA_REPORTING 0xf4 +#define PS2_BAT_OK 0xaa +#define PS2_MOUSE_ID 0x00 + +#define PS2_BYTE0_Y_OVERFLOW (1 << 7) +#define PS2_BYTE0_X_OVERFLOW (1 << 6) +#define PS2_BYTE0_Y_SIGN (1 << 5) +#define PS2_BYTE0_X_SIGN (1 << 4) +#define PS2_BYTE0_ALWAYS_ONE (1 << 3) +#define PS2_BYTE0_MIDDLE_DOWN (1 << 2) +#define PS2_BYTE0_RIGHT_DOWN (1 << 1) +#define PS2_BYTE0_LEFT_DOWN (1 << 0) + +static void call_callback(struct ps2mouse_data *d, uint8_t byte1, + uint8_t byte2, uint8_t byte3) +{ + uint8_t button; + int16_t xdelta; + int16_t ydelta; + + button = byte1 & (PS2_BYTE0_MIDDLE_DOWN | PS2_BYTE0_RIGHT_DOWN | + PS2_BYTE0_LEFT_DOWN); + + if (byte1 & PS2_BYTE0_X_OVERFLOW) { + xdelta = byte1 & PS2_BYTE0_X_SIGN ? -255 : 255; + } else { + xdelta = byte2; + if (byte1 & PS2_BYTE0_X_SIGN) + xdelta |= 0xff00; /* sign extend */ + } + + if (byte1 & PS2_BYTE0_Y_OVERFLOW) { + ydelta = byte1 & PS2_BYTE0_Y_SIGN ? -255 : 255; + } else { + ydelta = byte3; + if (byte1 & PS2_BYTE0_Y_SIGN) + ydelta |= 0xff00; /* sign extend */ + } + + d->callback(d->callback_data, button, xdelta, -ydelta); +} + +static void psm_consume(struct ps2mouse_data *d, uint8_t b) +{ + switch (d->state) { + case PS2MS_RESET: + if (b != PS2_CMD_ACK) + goto reset; + d->state = PS2MS_INIT; + return; + case PS2MS_INIT: + if (b != PS2_BAT_OK) + goto reset; + d->state = PS2MS_INIT2; + return; + case PS2MS_INIT2: + if (b != PS2_MOUSE_ID) { + EMSG("Unexpected byte 0x%x in state %d", b, d->state); + d->state = PS2MS_INACTIVE; + return; + } + d->state = PS2MS_INIT3; + d->serial->ops->putc(d->serial, PS2_CMD_ENABLE_DATA_REPORTING); + return; + case PS2MS_INIT3: + d->state = PS2MS_ACTIVE1; + return; + case PS2MS_ACTIVE1: + if (!(b & PS2_BYTE0_ALWAYS_ONE)) + goto reset; + d->bytes[0] = b; + d->state = PS2MS_ACTIVE2; + return; + case PS2MS_ACTIVE2: + d->bytes[1] = b; + d->state = PS2MS_ACTIVE3; + return; + case PS2MS_ACTIVE3: + d->state = PS2MS_ACTIVE1; + call_callback(d, d->bytes[0], d->bytes[1], b); + return; + default: + EMSG("Unexpected byte 0x%x in state %d", b, d->state); + return; + } + +reset: + EMSG("Unexpected byte 0x%x in state %d, resetting", b, d->state); + d->state = PS2MS_RESET; + d->serial->ops->putc(d->serial, PS2_CMD_RESET); +} + +static enum itr_return ps2mouse_itr_cb(struct itr_handler *h) +{ + struct ps2mouse_data *d = h->data; + + if (!d->serial->ops->have_rx_data(d->serial)) + return ITRR_NONE; + + while (true) { + psm_consume(d, d->serial->ops->getchar(d->serial)); + if (!d->serial->ops->have_rx_data(d->serial)) + return ITRR_HANDLED; + } +} +KEEP_PAGER(ps2mouse_itr_cb); + +void ps2mouse_init(struct ps2mouse_data *d, struct serial_chip *serial, + size_t serial_it, ps2mouse_callback cb, void *cb_data) +{ + memset(d, 0, sizeof(*d)); + d->serial = serial; + d->state = PS2MS_RESET; + d->itr_handler.it = serial_it; + d->itr_handler.flags = ITRF_TRIGGER_LEVEL; + d->itr_handler.handler = ps2mouse_itr_cb; + d->itr_handler.data = d; + d->callback = cb; + d->callback_data = cb_data; + + itr_add(&d->itr_handler); + itr_enable(serial_it); + d->serial->ops->putc(d->serial, PS2_CMD_RESET); +} |