Basic keyboard implementation

1 files changed, 123 insertions, 3 deletions

diff --git a/pit.c b/pit.c
index d52292e..1241766 100644
--- a/pit.c
+++ b/pit.c
@@ -16,13 +16,133 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+#include <arrlen.h>
+#include <cm4.h>
+#include <reg/gpio.h>
 #include <reg/pit.h>
+#include <reg/port.h>
+#include <reg/sim.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
 
 #include "pit.h"
+#include "usb/endpt1.h"
+#include "usb/keycodes.h"
+
+enum {
+	T0_CYCLES = 5000,
+};
+
+struct gpio {
+	uint32_t port;
+	uint32_t gpio;
+	uint32_t bit;
+	unsigned char pin;
+};
+#define GPIO_PIN(port, pin) { \
+	PORT##port##_BASE, \
+	GPIO##port##_BASE, \
+	BV((pin)), \
+	(pin), \
+}
+
+static const struct gpio cols[] = {
+	GPIO_PIN(B,  2),
+	GPIO_PIN(B,  3),
+	GPIO_PIN(B, 18),
+	GPIO_PIN(B, 19),
+	GPIO_PIN(C,  0),
+	GPIO_PIN(C,  8),
+	GPIO_PIN(C,  9),
+	GPIO_PIN(C, 10),
+	GPIO_PIN(C, 11),
+};
+
+static const struct gpio rows[] = {
+	GPIO_PIN(D, 0),
+	GPIO_PIN(D, 1),
+	GPIO_PIN(D, 4),
+	GPIO_PIN(D, 5),
+	GPIO_PIN(D, 6),
+	GPIO_PIN(D, 7),
+	GPIO_PIN(C, 1),
+	GPIO_PIN(C, 2),
+};
+
+/* COL AND ROW SWAPPED!!! */
+static enum keycode keymap[ARRLEN(rows)][ARRLEN(cols)] = {
+	{ /* S01 */ KEY_ESCAPE, KEY_1,		KEY_2,		KEY_3,		KEY_4,		KEY_5,		KEY_6,		KEY_7,		KEY_8, },
+	{ /* S10 */ KEY_9,	KEY_0,		KEY_MINUS,	KEY_EQUAL,	KEY_NONE,	KEY_BACKSPACE,	KEY_GRAVE,	KEY_TAB,	KEY_Q, },
+	{ /* S19 */ KEY_W,	KEY_E,		KEY_R,		KEY_T,		KEY_Y,		KEY_U,		KEY_I,		KEY_O,		KEY_P, },
+	{ /* S28 */ KEY_LSQUARE, KEY_RSQUARE,	KEY_NONE,	KEY_DELETE,	KEY_CAPSLK,	KEY_A,		KEY_S,		KEY_D,		KEY_F, },
+	{ /* S37 */ KEY_G,	KEY_H,		KEY_J,		KEY_K,		KEY_L,		KEY_SEMICOLON,	KEY_QUOTE,	KEY_BACKSLASH,	KEY_ENTER, },
+	{ /* S46 */ KEY_PGUP,	KEY_LSHIFT,	KEY_NU_BACKSLASH, KEY_Z,	KEY_X,		KEY_C,		KEY_V,		KEY_B,		KEY_N, },
+	{ /* S55 */ KEY_M,	KEY_COMMA,	KEY_PERIOD,	KEY_SLASH,	KEY_RSHIFT,	KEY_UP,		KEY_PGDN,	KEY_LCTRL,	KEY_LGUI, },
+	{ /* S64 */ KEY_LALT,	KEY_SPACE,	KEY_RALT,	KEY_NONE,	KEY_RCTRL,	KEY_LEFT,	KEY_DOWN,	KEY_RIGHT,	KEY_NONE, },
+};
 
 void pit_setup(void)
 {
-	/* TODO */
-	while (1)
-		;
+	/* Set up ports (could be done with GPC registers */
+	for (size_t i = 0; i < ARRLEN(cols); i++) {
+		SET_BIT(GPIO_PDDR(cols[i].gpio), cols[i].pin);
+		GPIO_PCOR(cols[i].gpio) = cols[i].bit;
+		PORT_PCR(cols[i].port, cols[i].pin) = BV(PCR_SRE) | BV(PCR_DSE)
+			| 1 << PCR_MUX;
+	}
+	for (size_t i = 0; i < ARRLEN(rows); i++) {
+		UNSET_BIT(GPIO_PDDR(rows[i].gpio), rows[i].pin);
+		PORT_PCR(rows[i].port, rows[i].pin) = BV(PCR_PFE) | BV(PCR_PE)
+			| 1 << PCR_MUX;
+	}
+
+	/* Enable clock */
+	SET_BIT(SIM_SCGC6, SCGC6_PIT);
+
+	/* NVIC Enable interrupt */
+	ISR_CLRPEND(68);
+	ISR_SETENA(68);
+	INTPRI(68) = 0x10;
+
+	/* First column strobe */
+	GPIO_PSOR(cols[0].gpio) = cols[0].bit;
+
+	/* Set up PIT0 */
+	PIT_MCR = 0;
+
+	PIT_LDVAL(0) = T0_CYCLES - 1;
+	PIT_TFLG(0) = BV(TFLG_TIF);
+	PIT_TCTRL(0) = BV(TCTRL_TIE) | BV(TCTRL_TEN);
+}
+
+static uint8_t kstates[ARRLEN(cols)][ARRLEN(rows)] = { 0 };
+
+static void key_state(int col, int row, bool state)
+{
+	uint8_t kstate;
+
+	kstate = kstates[col][row] = kstates[col][row] << 1 | state;
+
+	if (kstate == 0x7f)
+		usb_endpt1_setkey(keymap[row][col], true);
+	else if (kstate == 0x80)
+		usb_endpt1_setkey(keymap[row][col], false);
+}
+
+void pit0_isr(void)
+{
+	static unsigned char col = 0;
+
+	for (size_t row = 0; row < ARRLEN(rows); row++)
+		key_state(col, row, !!(GPIO_PDIR(rows[row].gpio) & rows[row].bit));
+
+	GPIO_PCOR(cols[col].gpio) = cols[col].bit;
+	col = (col + 1) % ARRLEN(cols);
+	GPIO_PSOR(cols[col].gpio) = cols[col].bit;
+
+	if (col == 0)
+		usb_endpt1_send();
+
+	PIT_TFLG(0) = BV(TFLG_TIF);
 }