diff options
Diffstat (limited to 'src/drivers/ao_ps2.c')
| -rw-r--r-- | src/drivers/ao_ps2.c | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/src/drivers/ao_ps2.c b/src/drivers/ao_ps2.c new file mode 100644 index 00000000..29eecea8 --- /dev/null +++ b/src/drivers/ao_ps2.c @@ -0,0 +1,419 @@ +/* + * Copyright © 2016 Keith Packard <keithp@keithp.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#include "ao.h" +#include "ao_ps2.h" +#include "ao_exti.h" + +static struct ao_fifo ao_ps2_rx_fifo; + +static uint16_t ao_ps2_tx; +static uint8_t ao_ps2_tx_count; + +static AO_TICK_TYPE ao_ps2_tick; +static uint16_t ao_ps2_value; +static uint8_t ao_ps2_count; + +uint8_t ao_ps2_stdin; + +uint8_t ao_ps2_scancode_set; + +#define AO_PS2_CLOCK_MODE(pull) ((pull) | AO_EXTI_MODE_FALLING | AO_EXTI_PRIORITY_MED) + +static void +ao_ps2_isr(void); + +static uint8_t +_ao_ps2_parity(uint8_t value) +{ + uint8_t parity = 1; + uint8_t b; + + for (b = 0; b < 8; b++) { + parity ^= (value & 1); + value >>= 1; + } + return parity; +} + +static int +_ao_ps2_poll(void) +{ + uint8_t u; + if (ao_fifo_empty(ao_ps2_rx_fifo)) { + return AO_READ_AGAIN; + } + ao_fifo_remove(ao_ps2_rx_fifo, u); + + return (int) u; +} + +uint8_t +ao_ps2_get(void) +{ + int c; + ao_arch_block_interrupts(); + while ((c = _ao_ps2_poll()) == AO_READ_AGAIN) + ao_sleep(&ao_ps2_rx_fifo); + ao_arch_release_interrupts(); + return (uint8_t) c; +} + + +int +ao_ps2_poll(void) +{ + int c; + ao_arch_block_interrupts(); + c = _ao_ps2_poll(); + ao_arch_release_interrupts(); + return (uint8_t) c; +} + +void +ao_ps2_put(uint8_t c) +{ + ao_arch_block_interrupts(); + ao_ps2_tx = ((uint16_t) c) | (_ao_ps2_parity(c) << 8) | (3 << 9); + ao_ps2_tx_count = 11; + ao_exti_disable(AO_PS2_CLOCK_PORT, AO_PS2_CLOCK_BIT); + ao_arch_release_interrupts(); + + /* pull the clock pin down */ + ao_enable_output(AO_PS2_CLOCK_PORT, AO_PS2_CLOCK_BIT, AO_PS2_CLOCK_PIN, 0); + ao_delay(0); + + /* pull the data pin down for the start bit */ + ao_enable_output(AO_PS2_DATA_PORT, AO_PS2_DATA_BIT, AO_PS2_DATA_PIN, 0); + ao_delay(0); + + /* switch back to input mode for the interrupt to work */ + ao_exti_setup(AO_PS2_CLOCK_PORT, AO_PS2_CLOCK_BIT, + AO_PS2_CLOCK_MODE(AO_EXTI_MODE_PULL_UP), + ao_ps2_isr); + ao_exti_enable(AO_PS2_CLOCK_PORT, AO_PS2_CLOCK_BIT); + + /* wait for the bits to drain */ + while (ao_ps2_tx_count) + ao_sleep(&ao_ps2_tx_count); + +} + +static uint8_t ao_ps2_down[128 / 8]; + +static void +ao_ps2_set_down(uint8_t code, uint8_t value) +{ + uint8_t shift = (code & 0x07); + uint8_t byte = code >> 3; + + ao_ps2_down[byte] = (ao_ps2_down[byte] & ~(1 << shift)) | (value << shift); +} + +uint8_t +ao_ps2_is_down(uint8_t code) +{ + uint8_t shift = (code & 0x07); + uint8_t byte = code >> 3; + + return (ao_ps2_down[byte] >> shift) & 1; +} + +static void +_ao_ps2_set_leds(void) +{ + uint8_t led = 0; + if (ao_ps2_is_down(AO_PS2_CAPS_LOCK)) + led |= AO_PS2_SET_LEDS_CAPS; + if (ao_ps2_is_down(AO_PS2_NUM_LOCK)) + led |= AO_PS2_SET_LEDS_NUM; + if (ao_ps2_is_down(AO_PS2_SCROLL_LOCK)) + led |= AO_PS2_SET_LEDS_SCROLL; + ao_arch_release_interrupts(); + ao_ps2_put(AO_PS2_SET_LEDS); + while (ao_ps2_get() != 0xfa); + ao_ps2_put(led); + ao_arch_block_interrupts(); +} + +static uint8_t +ao_ps2_is_lock(uint8_t code) { + switch (code) { + case AO_PS2_CAPS_LOCK: + case AO_PS2_NUM_LOCK: + case AO_PS2_SCROLL_LOCK: + return 1; + } + return 0; +} + +static void +_ao_ps2_set_scancode_set(uint8_t set) +{ + ao_ps2_scancode_set = set; + ao_arch_release_interrupts(); + ao_ps2_put(AO_PS2_SET_SCAN_CODE_SET); + while (ao_ps2_get() != 0xfa); + ao_ps2_put(set); + ao_ps2_put(AO_PS2_SET_KEY_TYPEMATIC_MAKE_BREAK); + while (ao_ps2_get() != 0xfa); + ao_arch_block_interrupts(); +} + +static int +_ao_ps2_poll_key(void) +{ + int c; + uint8_t set_led = 0; + static uint8_t saw_break; + + c = _ao_ps2_poll(); + if (c < 0) { + if (ao_ps2_scancode_set != 3) { + _ao_ps2_set_scancode_set(3); + } + return c; + } + + if (c == AO_PS2_BREAK) { + saw_break = 1; + return AO_READ_AGAIN; + } + if (c & 0x80) + return AO_READ_AGAIN; + + if (ao_ps2_is_lock(c)) { + if (saw_break) { + saw_break = 0; + return AO_READ_AGAIN; + } + if (ao_ps2_is_down(c)) + saw_break = 1; + set_led = 1; + } + if (saw_break) { + saw_break = 0; + ao_ps2_set_down(c, 0); + c |= 0x80; + } else + ao_ps2_set_down(c, 1); + if (set_led) + _ao_ps2_set_leds(); + + if (ao_ps2_scancode_set != 3) + _ao_ps2_set_scancode_set(3); + + return c; +} + +int +ao_ps2_poll_key(void) +{ + int c; + ao_arch_block_interrupts(); + c = _ao_ps2_poll_key(); + ao_arch_release_interrupts(); + return c; +} + +uint8_t +ao_ps2_get_key(void) +{ + int c; + ao_arch_block_interrupts(); + while ((c = _ao_ps2_poll_key()) == AO_READ_AGAIN) + ao_sleep(&ao_ps2_rx_fifo); + ao_arch_release_interrupts(); + return (uint8_t) c; +} + +static const uint8_t ao_ps2_asciimap[128][2] = { + [AO_PS2_A] = { 'a', 'A' }, + [AO_PS2_B] = { 'b', 'B' }, + [AO_PS2_C] = { 'c', 'C' }, + [AO_PS2_D] = { 'd', 'D' }, + [AO_PS2_E] = { 'e', 'E' }, + [AO_PS2_F] = { 'f', 'F' }, + [AO_PS2_G] = { 'g', 'G' }, + [AO_PS2_H] = { 'h', 'H' }, + [AO_PS2_I] = { 'i', 'I' }, + [AO_PS2_J] = { 'j', 'J' }, + [AO_PS2_K] = { 'k', 'K' }, + [AO_PS2_L] = { 'l', 'L' }, + [AO_PS2_M] = { 'm', 'M' }, + [AO_PS2_N] = { 'n', 'N' }, + [AO_PS2_O] = { 'o', 'O' }, + [AO_PS2_P] = { 'p', 'P' }, + [AO_PS2_Q] = { 'q', 'Q' }, + [AO_PS2_R] = { 'r', 'R' }, + [AO_PS2_S] = { 's', 'S' }, + [AO_PS2_T] = { 't', 'T' }, + [AO_PS2_U] = { 'u', 'U' }, + [AO_PS2_V] = { 'v', 'V' }, + [AO_PS2_W] = { 'w', 'W' }, + [AO_PS2_X] = { 'x', 'X' }, + [AO_PS2_Y] = { 'y', 'Y' }, + [AO_PS2_Z] = { 'z', 'Z' }, + + [AO_PS2_0] = { '0', ')' }, + [AO_PS2_1] = { '1', '!' }, + [AO_PS2_2] = { '2', '@' }, + [AO_PS2_3] = { '3', '#' }, + [AO_PS2_4] = { '4', '$' }, + [AO_PS2_5] = { '5', '%' }, + [AO_PS2_6] = { '6', '^' }, + [AO_PS2_7] = { '7', '&' }, + [AO_PS2_8] = { '8', '*' }, + [AO_PS2_9] = { '9', '(' }, + + [AO_PS2_GRAVE] = { '`', '~' }, + [AO_PS2_HYPHEN] = { '-', '_' }, + [AO_PS2_EQUAL] = { '=', '+' }, + [AO_PS2_BACKSLASH] = { '\\', '|' }, + [AO_PS2_BACKSPACE] = { '\010', '\010' }, + [AO_PS2_SPACE] = { ' ', ' ' }, + [AO_PS2_TAB] = { '\t', '\t' }, + + [AO_PS2_ENTER] = { '\r', '\r' }, + [AO_PS2_ESC] = { '\033', '\033' }, + + [AO_PS2_OPEN_SQ] = { '[', '{' }, + [AO_PS2_DELETE] = { '\177', '\177' }, + + [AO_PS2_KP_TIMES] = { '*', '*' }, + [AO_PS2_KP_PLUS] = { '+', '+' }, + [AO_PS2_KP_ENTER] = { '\r', '\r' }, + [AO_PS2_KP_DECIMAL] = { '.', '.' }, + [AO_PS2_KP_0] = { '0', '0' }, + [AO_PS2_KP_1] = { '1', '1' }, + [AO_PS2_KP_2] = { '2', '2' }, + [AO_PS2_KP_3] = { '3', '3' }, + [AO_PS2_KP_4] = { '4', '4' }, + [AO_PS2_KP_5] = { '5', '5' }, + [AO_PS2_KP_6] = { '6', '6' }, + [AO_PS2_KP_7] = { '7', '7' }, + [AO_PS2_KP_8] = { '8', '8' }, + [AO_PS2_KP_9] = { '9', '9' }, + [AO_PS2_CLOSE_SQ] = { ']', '}' }, + [AO_PS2_SEMICOLON] = { ';', ':' }, + [AO_PS2_ACUTE] = { '\'', '"' }, + [AO_PS2_COMMA] = { ',', '<' }, + [AO_PS2_PERIOD] = { '.', '>' }, + [AO_PS2_SLASH] = { '/', '?' }, +}; + +int +ao_ps2_ascii(uint8_t key) +{ + uint8_t col; + char a; + + /* Skip key releases */ + if (key & 0x80) + return AO_READ_AGAIN; + + col = 0; + if (ao_ps2_is_down(AO_PS2_L_SHIFT) || ao_ps2_is_down(AO_PS2_R_SHIFT)) + col = 1; + + /* caps lock */ + a = ao_ps2_asciimap[key][0]; + if (!a) + return AO_READ_AGAIN; + + if ('a' <= a && a <= 'z') + if (ao_ps2_is_down(AO_PS2_CAPS_LOCK)) + col ^= 1; + a = ao_ps2_asciimap[key][col]; + if ('@' <= a && a <= 0x7f && (ao_ps2_is_down(AO_PS2_L_CTRL) || ao_ps2_is_down(AO_PS2_R_CTRL))) + a &= 0x1f; + return a; +} + +int +_ao_ps2_pollchar(void) +{ + int key; + + key = _ao_ps2_poll_key(); + if (key < 0) + return key; + return ao_ps2_ascii(key); +} + +char +ao_ps2_getchar(void) +{ + int c; + ao_arch_block_interrupts(); + while ((c = _ao_ps2_pollchar()) == AO_READ_AGAIN) + ao_sleep(&ao_ps2_rx_fifo); + ao_arch_release_interrupts(); + return (char) c; +} + +static void +ao_ps2_isr(void) +{ + uint8_t bit; + + if (ao_ps2_tx_count) { + ao_gpio_set(AO_PS2_DATA_PORT, AO_PS2_DATA_BIT, AO_PS2_DATA_PIN, ao_ps2_tx&1); + ao_ps2_tx >>= 1; + ao_ps2_tx_count--; + if (!ao_ps2_tx_count) { + ao_enable_input(AO_PS2_DATA_PORT, AO_PS2_DATA_BIT, AO_EXTI_MODE_PULL_UP); + ao_wakeup(&ao_ps2_tx_count); + } + return; + } + /* reset if its been a while */ + if ((ao_tick_count - ao_ps2_tick) > AO_MS_TO_TICKS(100)) + ao_ps2_count = 0; + ao_ps2_tick = ao_tick_count; + + bit = ao_gpio_get(AO_PS2_DATA_PORT, AO_PS2_DATA_BIT, AO_PS2_DATA_PIN); + if (ao_ps2_count == 0) { + /* check for start bit, ignore if not zero */ + if (bit) + return; + ao_ps2_value = 0; + } else if (ao_ps2_count < 9) { + ao_ps2_value |= (bit << (ao_ps2_count - 1)); + } else if (ao_ps2_count == 10) { + ao_fifo_insert(ao_ps2_rx_fifo, ao_ps2_value); + ao_wakeup(&ao_ps2_rx_fifo); + if (ao_ps2_stdin) + ao_wakeup(&ao_stdin_ready); + ao_ps2_count = 0; + return; + } + ao_ps2_count++; +} + +void +ao_ps2_init(void) +{ + ao_enable_input(AO_PS2_DATA_PORT, AO_PS2_DATA_BIT, + AO_EXTI_MODE_PULL_UP); + + ao_enable_port(AO_PS2_CLOCK_PORT); + + ao_exti_setup(AO_PS2_CLOCK_PORT, AO_PS2_CLOCK_BIT, + AO_PS2_CLOCK_MODE(AO_EXTI_MODE_PULL_UP), + ao_ps2_isr); + ao_exti_enable(AO_PS2_CLOCK_PORT, AO_PS2_CLOCK_BIT); + + ao_ps2_scancode_set = 2; +} |