X-Git-Url: https://git.friedersdorff.com/?a=blobdiff_plain;f=ps2.c;h=8a05916210d77b4741c060c543a45fad75a102e2;hb=e65575d4a5f03a90adfa9850cb71a5d0448098cd;hp=adb425ae3345e0d548a80a5cdcb8c0e0c5d9474b;hpb=2a562a4191a5b9e88731efb5eabd921821f25f7e;p=max%2Ftmk_keyboard.git

diff --git a/ps2.c b/ps2.c
index adb425ae..8a059162 100644
--- a/ps2.c
+++ b/ps2.c
@@ -1,5 +1,5 @@
 /*
-Copyright (c) 2010 Jun WAKO <wakojun@gmail.com>
+Copyright 2010,2011 Jun WAKO <wakojun@gmail.com>
 
 This software is licensed with a Modified BSD License.
 All of this is supposed to be Free Software, Open Source, DFSG-free,
@@ -34,14 +34,16 @@ 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 <stdbool.h>
 #include <avr/io.h>
+#include <avr/interrupt.h>
 #include <util/delay.h>
 #include "ps2.h"
-#include "print.h"
 #include "debug.h"
 
 
+static uint8_t recv_data(void);
 static inline void clock_lo(void);
 static inline void clock_hi(void);
 static inline bool clock_in(void);
@@ -52,6 +54,8 @@ static inline uint16_t wait_clock_lo(uint16_t us);
 static inline uint16_t wait_clock_hi(uint16_t us);
 static inline uint16_t wait_data_lo(uint16_t us);
 static inline uint16_t wait_data_hi(uint16_t us);
+static inline void idle(void);
+static inline void inhibit(void);
 
 
 /*
@@ -79,38 +83,40 @@ http://www.mcamafia.de/pdf/ibm_hitrc07.pdf
     } \
 } while (0)
 
-#define WAIT_NORETRY(stat, us, err) do { \
-    if (!wait_##stat(us)) { \
-        ps2_error = err; \
-        return 0; \
-    } \
-} while (0)
-
 
 uint8_t ps2_error = PS2_ERR_NONE;
 
 
 void ps2_host_init(void)
 {
-    /* inhibit */
-    clock_lo();
-    data_hi();
+#ifdef PS2_INT_ENABLE
+    PS2_INT_ENABLE();
+    idle();
+#else
+    inhibit();
+#endif
 }
 
+// TODO: send using interrupt if available
 uint8_t ps2_host_send(uint8_t data)
 {
+    uint8_t res = 0;
     bool parity = true;
-    ps2_error = 0;
-
-    /* request to send */
-    clock_lo();
-    data_lo();
+    ps2_error = PS2_ERR_NONE;
+#ifdef PS2_INT_DISABLE
+    PS2_INT_DISABLE();
+#endif
+    /* terminate a transmission if we have */
+    inhibit();
     _delay_us(100);
+
     /* start bit [1] */
+    data_lo();
     clock_hi();
     WAIT(clock_lo, 15000, 1);
     /* data [2-9] */
     for (uint8_t i = 0; i < 8; i++) {
+        _delay_us(15);
         if (data&(1<<i)) {
             parity = !parity;
             data_hi();
@@ -121,41 +127,209 @@ uint8_t ps2_host_send(uint8_t data)
         WAIT(clock_lo, 50, 3);
     }
     /* parity [10] */
+    _delay_us(15);
     if (parity) { data_hi(); } else { data_lo(); }
     WAIT(clock_hi, 50, 4);
     WAIT(clock_lo, 50, 5);
     /* stop bit [11] */
+    _delay_us(15);
     data_hi();
     /* ack [12] */
     WAIT(data_lo, 50, 6);
     WAIT(clock_lo, 50, 7);
+
+    /* wait for idle state */
     WAIT(clock_hi, 50, 8);
     WAIT(data_hi, 50, 9);
 
-    /* inhibit device to send */
-    clock_lo();
-
-    return 1;
+    res = ps2_host_recv_response();
 ERROR:
-    return 0;
+#ifdef PS2_INT_ENABLE
+    PS2_INT_ENABLE();
+    idle();
+#else
+    inhibit();
+#endif
+    return res;
 }
 
-uint8_t ps2_host_recv(void)
+/* receive data when host want else inhibit communication */
+uint8_t ps2_host_recv_response(void)
 {
     uint8_t data = 0;
-    bool parity = true;
-    ps2_error = 0;
 
-    /* cancel to sync */
-    clock_lo();
+    /* terminate a transmission if we have */
+    inhibit();
     _delay_us(100);
 
     /* release lines(idle state) */
-    clock_hi();
-    data_hi();
+    idle();
+
+    /* wait start bit */
+    wait_clock_lo(2000);
+    data = recv_data();
+
+    inhibit();
+    return data;
+}
+
+#ifndef PS2_INT_VECT
+uint8_t ps2_host_recv(void)
+{
+    return ps2_host_recv_response();
+}
+#else
+/* ring buffer to store ps/2 key data */
+#define PBUF_SIZE 8
+static uint8_t pbuf[PBUF_SIZE];
+static uint8_t pbuf_head = 0;
+static uint8_t pbuf_tail = 0;
+static inline void pbuf_enqueue(uint8_t data)
+{
+    if (!data)
+        return;
+
+    uint8_t sreg = SREG;
+    cli();
+    uint8_t next = (pbuf_head + 1) % PBUF_SIZE;
+    if (next != pbuf_tail) {
+        pbuf[pbuf_head] = data;
+        pbuf_head = next;
+    } else {
+        debug("pbuf: full\n");
+    }
+    SREG = sreg;
+}
+static inline uint8_t pbuf_dequeue(void)
+{
+    uint8_t val = 0;
+
+    uint8_t sreg = SREG;
+    cli();
+    if (pbuf_head != pbuf_tail) {
+        val = pbuf[pbuf_tail];
+        pbuf_tail = (pbuf_tail + 1) % PBUF_SIZE;
+    }
+    SREG = sreg;
+
+    return val;
+}
+
+/* get data received by interrupt */
+uint8_t ps2_host_recv(void)
+{
+    if (ps2_error) {
+        print("x");
+        phex(ps2_error);
+        ps2_host_send(0xFE);    // request to resend
+        ps2_error = PS2_ERR_NONE;
+    }
+    idle();
+    return pbuf_dequeue();
+}
+
+#if 0
+#define DEBUGP_INIT() do { DDRC = 0xFF; } while (0)
+#define DEBUGP(x) do { PORTC = x; } while (0)
+#else
+#define DEBUGP_INIT()
+#define DEBUGP(x)
+#endif
+ISR(PS2_INT_VECT)
+{
+    static enum {
+        INIT,
+        START,
+        BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7,
+        PARITY,
+        STOP,
+    } state = INIT;
+    static uint8_t data = 0;
+    static uint8_t parity = 1;
+
+    // TODO: abort if elapse 100us from previous interrupt
+
+    // return unless falling edge
+    if (clock_in()) {
+        goto RETURN;
+    }
+
+    state++;
+    DEBUGP(state);
+    switch (state) {
+        case START:
+            if (data_in())
+                goto ERROR;
+            break;
+        case BIT0:
+        case BIT1:
+        case BIT2:
+        case BIT3:
+        case BIT4:
+        case BIT5:
+        case BIT6:
+        case BIT7:
+            data >>= 1;
+            if (data_in()) {
+                data |= 0x80;
+                parity++;
+            }
+            break;
+        case PARITY:
+            if (data_in()) {
+                if (!(parity & 0x01))
+                    goto ERROR;
+            } else {
+                if (parity & 0x01)
+                    goto ERROR;
+            }
+            break;
+        case STOP:
+            if (!data_in())
+                goto ERROR;
+            pbuf_enqueue(data);
+            goto DONE;
+            break;
+        default:
+            goto ERROR;
+    }
+    goto RETURN;
+ERROR:
+    DEBUGP(0x0F);
+    inhibit();
+    ps2_error = state;
+DONE:
+    state = INIT;
+    data = 0;
+    parity = 1;
+RETURN:
+    return;
+}
+#endif
+
+
+static void ps2_reset(void)
+{
+    ps2_host_send(0xFF);
+}
+
+/* send LED state to keyboard */
+void ps2_host_set_led(uint8_t led)
+{
+    ps2_host_send(0xED);
+    ps2_host_send(led);
+}
+
+
+/* called after start bit comes */
+static uint8_t recv_data(void)
+{
+    uint8_t data = 0;
+    bool parity = true;
+    ps2_error = PS2_ERR_NONE;
 
     /* start bit [1] */
-    WAIT(clock_lo, 20000, 1);
+    WAIT(clock_lo, 1, 1);
     WAIT(data_lo, 1, 2);
     WAIT(clock_hi, 50, 3);
 
@@ -182,15 +356,11 @@ uint8_t ps2_host_recv(void)
     WAIT(data_hi, 1, 9);
     WAIT(clock_hi, 50, 10);
 
-    /* inhibit device to send */
-    clock_lo();
-
     return data;
 ERROR:
     return 0;
 }
 
-
 static inline void clock_lo()
 {
     PS2_CLOCK_PORT &= ~(1<<PS2_CLOCK_BIT);
@@ -206,6 +376,7 @@ static inline bool clock_in()
 {
     PS2_CLOCK_DDR  &= ~(1<<PS2_CLOCK_BIT);
     PS2_CLOCK_PORT |=  (1<<PS2_CLOCK_BIT);
+    _delay_us(1);
     return PS2_CLOCK_PIN&(1<<PS2_CLOCK_BIT);
 }
 static inline void data_lo()
@@ -223,6 +394,7 @@ static inline bool data_in()
 {
     PS2_DATA_DDR  &= ~(1<<PS2_DATA_BIT);
     PS2_DATA_PORT |=  (1<<PS2_DATA_BIT);
+    _delay_us(1);
     return PS2_DATA_PIN&(1<<PS2_DATA_BIT);
 }
 
@@ -246,3 +418,17 @@ static inline uint16_t wait_data_hi(uint16_t us)
     while (!data_in() && us)  { asm(""); _delay_us(1); us--; }
     return us;
 }
+
+/* idle state that device can send */
+static inline void idle(void)
+{
+    clock_hi();
+    data_hi();
+}
+
+/* inhibit device to send */
+static inline void inhibit(void)
+{
+    clock_lo();
+    data_hi();
+}