From 4eb27ee89038e934dcb498df7508199efd9c93f1 Mon Sep 17 00:00:00 2001
From: tmk <nobody@nowhere>
Date: Thu, 28 Nov 2013 14:20:00 +0900
Subject: [PATCH] Add ps2_interrupt.c

---
 protocol.mk                         |   2 +-
 protocol/ps2_busywait.c             |  51 ++--
 protocol/{ps2.c => ps2_interrupt.c} | 358 +++++++---------------------
 protocol/ps2_usart.c                |  23 +-
 4 files changed, 124 insertions(+), 310 deletions(-)
 rename protocol/{ps2.c => ps2_interrupt.c} (51%)

diff --git a/protocol.mk b/protocol.mk
index e3320087..7f561e62 100644
--- a/protocol.mk
+++ b/protocol.mk
@@ -13,7 +13,7 @@ ifdef PS2_USE_BUSYWAIT
 endif
 
 ifdef PS2_USE_INT
-    SRC += protocol/ps2.c
+    SRC += protocol/ps2_interrupt.c
     OPT_DEFS += -DPS2_USE_INT
 endif
 
diff --git a/protocol/ps2_busywait.c b/protocol/ps2_busywait.c
index 5ab37787..05dd7b27 100644
--- a/protocol/ps2_busywait.c
+++ b/protocol/ps2_busywait.c
@@ -35,16 +35,16 @@ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 */
 
+/*
+ * PS/2 protocol busywait version
+ */
+
 #include <stdbool.h>
 #include <util/delay.h>
 #include "ps2.h"
 #include "debug.h"
 
 
-/*
- * PS/2 protocol busywait version
- */
-
 #define WAIT(stat, us, err) do { \
     if (!wait_##stat(us)) { \
         ps2_error = err; \
@@ -52,6 +52,7 @@ POSSIBILITY OF SUCH DAMAGE.
     } \
 } while (0)
 
+
 uint8_t ps2_error = PS2_ERR_NONE;
 
 
@@ -65,18 +66,19 @@ void ps2_host_init(void)
 
 uint8_t ps2_host_send(uint8_t data)
 {
-    uint8_t res = 0;
     bool parity = true;
     ps2_error = PS2_ERR_NONE;
+
     /* terminate a transmission if we have */
     inhibit();
-    _delay_us(200); // at least 100us
+    _delay_us(100); // 100us [4]p.13, [5]p.50
 
-    /* start bit [1] */
+    /* 'Request to Send' and Start bit */
     data_lo();
     clock_hi();
-    WAIT(clock_lo, 20000, 10);   // may take 15ms at most until device starts clocking
-    /* data [2-9] */
+    WAIT(clock_lo, 10000, 10);   // 10ms [5]p.50
+
+    /* Data bit */
     for (uint8_t i = 0; i < 8; i++) {
         _delay_us(15);
         if (data&(1<<i)) {
@@ -88,15 +90,18 @@ uint8_t ps2_host_send(uint8_t data)
         WAIT(clock_hi, 50, 2);
         WAIT(clock_lo, 50, 3);
     }
-    /* parity [10] */
+
+    /* Parity bit */
     _delay_us(15);
     if (parity) { data_hi(); } else { data_lo(); }
     WAIT(clock_hi, 50, 4);
     WAIT(clock_lo, 50, 5);
-    /* stop bit [11] */
+
+    /* Stop bit */
     _delay_us(15);
     data_hi();
-    /* ack [12] */
+
+    /* Ack */
     WAIT(data_lo, 50, 6);
     WAIT(clock_lo, 50, 7);
 
@@ -105,17 +110,16 @@ uint8_t ps2_host_send(uint8_t data)
     WAIT(data_hi, 50, 9);
 
     inhibit();
-    res = ps2_host_recv_response();
+    return ps2_host_recv_response();
 ERROR:
     inhibit();
-    return res;
+    return 0;
 }
 
 /* receive data when host want else inhibit communication */
 uint8_t ps2_host_recv_response(void)
 {
-    // Command might take 20ms to response([3]p.21)
-    // TrackPoint might take 25ms ([5]2.7)
+    // Command may take 25ms/20ms at most([5]p.46, [3]p.21)
     // 250 * 100us(wait for start bit in ps2_host_recv)
     uint8_t data = 0;
     uint8_t try = 250;
@@ -125,14 +129,6 @@ uint8_t ps2_host_recv_response(void)
     return data;
 }
 
-/* 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 */
 uint8_t ps2_host_recv(void)
 {
@@ -180,3 +176,10 @@ ERROR:
     inhibit();
     return 0;
 }
+
+/* send LED state to keyboard */
+void ps2_host_set_led(uint8_t led)
+{
+    ps2_host_send(0xED);
+    ps2_host_send(led);
+}
diff --git a/protocol/ps2.c b/protocol/ps2_interrupt.c
similarity index 51%
rename from protocol/ps2.c
rename to protocol/ps2_interrupt.c
index 4886b16d..355d4e82 100644
--- a/protocol/ps2.c
+++ b/protocol/ps2_interrupt.c
@@ -35,49 +35,16 @@ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 */
 
+/*
+ * PS/2 protocol Pin interrupt version
+ */
+
 #include <stdbool.h>
-#include <avr/io.h>
-#include <avr/interrupt.h>
 #include <util/delay.h>
 #include "ps2.h"
 #include "debug.h"
 
 
-#ifndef PS2_USE_INT
-static uint8_t recv_data(void);
-#endif
-static inline void clock_lo(void);
-static inline void clock_hi(void);
-static inline bool clock_in(void);
-static inline void data_lo(void);
-static inline void data_hi(void);
-static inline bool data_in(void);
-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);
-
-
-/*
-Primitive PS/2 Library for AVR
-==============================
-Host side is only supported now.
-
-
-I/O control
------------
-High state is asserted by input with pull up.
-
-
-PS/2 References
----------------
-http://www.computer-engineering.org/ps2protocol/
-http://www.mcamafia.de/pdf/ibm_hitrc07.pdf
-*/
-
-
 #define WAIT(stat, us, err) do { \
     if (!wait_##stat(us)) { \
         ps2_error = err; \
@@ -89,38 +56,38 @@ http://www.mcamafia.de/pdf/ibm_hitrc07.pdf
 uint8_t ps2_error = PS2_ERR_NONE;
 
 
+static inline uint8_t pbuf_dequeue(void);
+static inline void pbuf_enqueue(uint8_t data);
+static inline bool pbuf_has_data(void);
+static inline void pbuf_clear(void);
+
+
 void ps2_host_init(void)
 {
-    // POR(150-2000ms) plus BAT(300-500ms) may take 2.5sec([3]p.20)
-    _delay_ms(2500);
-
-#ifdef PS2_USE_INT
+    idle();
     PS2_INT_INIT();
     PS2_INT_ON();
-    idle();
-#else
-    inhibit();
-#endif
+    // POR(150-2000ms) plus BAT(300-500ms) may take 2.5sec([3]p.20)
+    //_delay_ms(2500);
 }
 
-// TODO: send using interrupt if available
 uint8_t ps2_host_send(uint8_t data)
 {
-    uint8_t res = 0;
     bool parity = true;
     ps2_error = PS2_ERR_NONE;
-#ifdef PS2_USE_INT
+
     PS2_INT_OFF();
-#endif
+
     /* terminate a transmission if we have */
     inhibit();
-    _delay_us(200); // at least 100us
+    _delay_us(100); // 100us [4]p.13, [5]p.50
 
-    /* start bit [1] */
+    /* 'Request to Send' and Start bit */
     data_lo();
     clock_hi();
-    WAIT(clock_lo, 20000, 10);   // may take 15ms at most until device starts clocking
-    /* data [2-9] */
+    WAIT(clock_lo, 10000, 10);   // 10ms [5]p.50
+
+    /* Data bit[2-9] */
     for (uint8_t i = 0; i < 8; i++) {
         _delay_us(15);
         if (data&(1<<i)) {
@@ -132,15 +99,18 @@ uint8_t ps2_host_send(uint8_t data)
         WAIT(clock_hi, 50, 2);
         WAIT(clock_lo, 50, 3);
     }
-    /* parity [10] */
+
+    /* Parity bit */
     _delay_us(15);
     if (parity) { data_hi(); } else { data_lo(); }
     WAIT(clock_hi, 50, 4);
     WAIT(clock_lo, 50, 5);
-    /* stop bit [11] */
+
+    /* Stop bit */
     _delay_us(15);
     data_hi();
-    /* ack [12] */
+
+    /* Ack */
     WAIT(data_lo, 50, 6);
     WAIT(clock_lo, 50, 7);
 
@@ -148,107 +118,35 @@ uint8_t ps2_host_send(uint8_t data)
     WAIT(clock_hi, 50, 8);
     WAIT(data_hi, 50, 9);
 
-#ifdef PS2_USE_INT
-    PS2_INT_ON();
-#endif
-    res = ps2_host_recv_response();
-ERROR:
-#ifdef PS2_USE_INT
-    PS2_INT_ON();
     idle();
-#else
-    inhibit();
-#endif
-    return res;
+    PS2_INT_ON();
+    return ps2_host_recv_response();
+ERROR:
+    idle();
+    PS2_INT_ON();
+    return 0;
 }
 
-#ifndef PS2_USE_INT
-/* receive data when host want else inhibit communication */
 uint8_t ps2_host_recv_response(void)
 {
-    // Command might take 20ms to response([3]p.21)
-    // TrackPoint might take 25ms ([5]2.7)
-    uint8_t data = 0;
-    uint8_t try = 200;
-    while (try-- && (data = ps2_host_recv())) ;
-    return data;
-}
-#endif
-
-#ifndef PS2_USE_INT
-uint8_t ps2_host_recv(void)
-{
-    uint8_t data = 0;
-
-    /* release lines(idle state) */
-    idle();
-
-    /* wait start bit */
-    wait_clock_lo(100); // TODO: this is enough?
-    data = recv_data();
-
-    inhibit();
-    return data;
-}
-#else
-/* ring buffer to store ps/2 key data */
-#define PBUF_SIZE 32
-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)
-{
-    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");
+    // Command may take 25ms/20ms at most([5]p.46, [3]p.21)
+    uint8_t retry = 25;
+    while (retry-- && !pbuf_has_data()) {
+        _delay_ms(1);
     }
-    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;
-}
-static inline bool pbuf_has_data(void)
-{
-    uint8_t sreg = SREG;
-    cli();
-    bool has_data = (pbuf_head != pbuf_tail);
-    SREG = sreg;
-    return has_data;
-}
-static inline void pbuf_clear(void)
-{
-    uint8_t sreg = SREG;
-    cli();
-    pbuf_head = pbuf_tail = 0;
-    SREG = sreg;
+    return pbuf_dequeue();
 }
 
 /* get data received by interrupt */
 uint8_t ps2_host_recv(void)
 {
-    return pbuf_dequeue();
-}
-
-uint8_t ps2_host_recv_response(void)
-{
-    while (!pbuf_has_data()) ;
-    return pbuf_dequeue();
+    if (pbuf_has_data()) {
+        ps2_error = PS2_ERR_NONE;
+        return pbuf_dequeue();
+    } else {
+        ps2_error = PS2_ERR_NODATA;
+        return 0;
+    }
 }
 
 ISR(PS2_INT_VECT)
@@ -303,7 +201,6 @@ ISR(PS2_INT_VECT)
             if (!data_in())
                 goto ERROR;
             pbuf_enqueue(data);
-//phex(data);
             goto DONE;
             break;
         default:
@@ -311,7 +208,6 @@ ISR(PS2_INT_VECT)
     }
     goto RETURN;
 ERROR:
-    inhibit();
     ps2_error = state;
 DONE:
     state = INIT;
@@ -320,8 +216,6 @@ DONE:
 RETURN:
     return;
 }
-#endif
-
 
 /* send LED state to keyboard */
 void ps2_host_set_led(uint8_t led)
@@ -331,139 +225,53 @@ void ps2_host_set_led(uint8_t led)
 }
 
 
-#ifndef PS2_USE_INT
-/* called after start bit comes */
-static uint8_t recv_data(void)
+/*--------------------------------------------------------------------
+ * Ring buffer to store scan codes from keyboard
+ *------------------------------------------------------------------*/
+#define PBUF_SIZE 32
+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)
 {
-    uint8_t data = 0;
-    bool parity = true;
-    ps2_error = PS2_ERR_NONE;
-
-    /* start bit [1] */
-    WAIT(clock_lo, 1, 1);
-    WAIT(data_lo, 1, 2);
-    WAIT(clock_hi, 50, 3);
-
-    /* data [2-9] */
-    for (uint8_t i = 0; i < 8; i++) {
-        WAIT(clock_lo, 50, 4);
-        if (data_in()) {
-            parity = !parity;
-            data |= (1<<i);
-        }
-        WAIT(clock_hi, 50, 5);
+    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;
 
-    /* parity [10] */
-    WAIT(clock_lo, 50, 6);
-    if (data_in() != parity) {
-        ps2_error = PS2_ERR_PARITY;
-        goto ERROR;
+    uint8_t sreg = SREG;
+    cli();
+    if (pbuf_head != pbuf_tail) {
+        val = pbuf[pbuf_tail];
+        pbuf_tail = (pbuf_tail + 1) % PBUF_SIZE;
     }
-    WAIT(clock_hi, 50, 7);
+    SREG = sreg;
 
-    /* stop bit [11] */
-    WAIT(clock_lo, 50, 8);
-    WAIT(data_hi, 1, 9);
-    WAIT(clock_hi, 50, 10);
-
-    return data;
-ERROR:
-    return 0;
+    return val;
 }
-#endif
-
-static inline void clock_lo()
+static inline bool pbuf_has_data(void)
 {
-    PS2_CLOCK_PORT &= ~(1<<PS2_CLOCK_BIT);
-    PS2_CLOCK_DDR  |=  (1<<PS2_CLOCK_BIT);
+    uint8_t sreg = SREG;
+    cli();
+    bool has_data = (pbuf_head != pbuf_tail);
+    SREG = sreg;
+    return has_data;
 }
-static inline void clock_hi()
+static inline void pbuf_clear(void)
 {
-    /* input with pull up */
-    PS2_CLOCK_DDR  &= ~(1<<PS2_CLOCK_BIT);
-    PS2_CLOCK_PORT |=  (1<<PS2_CLOCK_BIT);
-}
-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()
-{
-    PS2_DATA_PORT &= ~(1<<PS2_DATA_BIT);
-    PS2_DATA_DDR  |=  (1<<PS2_DATA_BIT);
-}
-static inline void data_hi()
-{
-    /* input with pull up */
-    PS2_DATA_DDR  &= ~(1<<PS2_DATA_BIT);
-    PS2_DATA_PORT |=  (1<<PS2_DATA_BIT);
-}
-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);
+    uint8_t sreg = SREG;
+    cli();
+    pbuf_head = pbuf_tail = 0;
+    SREG = sreg;
 }
 
-static inline uint16_t wait_clock_lo(uint16_t us)
-{
-    while (clock_in()  && us) { asm(""); _delay_us(1); us--; }
-    return us;
-}
-static inline uint16_t wait_clock_hi(uint16_t us)
-{
-    while (!clock_in() && us) { asm(""); _delay_us(1); us--; }
-    return us;
-}
-static inline uint16_t wait_data_lo(uint16_t us)
-{
-    while (data_in() && us)  { asm(""); _delay_us(1); us--; }
-    return us;
-}
-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();
-}
-
-
-/* PS/2 Resources
- *
- * [1] The PS/2 Mouse/Keyboard Protocol
- * http://www.computer-engineering.org/ps2protocol/
- * Concise and thorough primer of PS/2 protocol.
- *
- * [2] Keyboard and Auxiliary Device Controller
- * http://www.mcamafia.de/pdf/ibm_hitrc07.pdf
- * Signal Timing and Format
- *
- * [3] Keyboards(101- and 102-key)
- * http://www.mcamafia.de/pdf/ibm_hitrc11.pdf
- * Keyboard Layout, Scan Code Set, POR, and Commands.
- *
- * [4] PS/2 Reference Manuals
- * http://www.mcamafia.de/pdf/ibm_hitrc07.pdf
- * Collection of IBM Personal System/2 documents.
- *
- * [5] TrackPoint Engineering Specifications for version 3E
- * https://web.archive.org/web/20100526161812/http://wwwcssrv.almaden.ibm.com/trackpoint/download.html
- */
diff --git a/protocol/ps2_usart.c b/protocol/ps2_usart.c
index d4911428..27947143 100644
--- a/protocol/ps2_usart.c
+++ b/protocol/ps2_usart.c
@@ -82,13 +82,14 @@ uint8_t ps2_host_send(uint8_t data)
 
     /* terminate a transmission if we have */
     inhibit();
-    _delay_us(100);
+    _delay_us(100); // [4]p.13
 
-    /* start bit [1] */
+    /* 'Request to Send' and Start bit */
     data_lo();
     clock_hi();
-    WAIT(clock_lo, 15000, 1);
-    /* data [2-9] */
+    WAIT(clock_lo, 10000, 10);   // 10ms [5]p.50
+
+    /* Data bit[2-9] */
     for (uint8_t i = 0; i < 8; i++) {
         _delay_us(15);
         if (data&(1<<i)) {
@@ -100,15 +101,18 @@ uint8_t ps2_host_send(uint8_t data)
         WAIT(clock_hi, 50, 2);
         WAIT(clock_lo, 50, 3);
     }
-    /* parity [10] */
+
+    /* Parity bit */
     _delay_us(15);
     if (parity) { data_hi(); } else { data_lo(); }
     WAIT(clock_hi, 50, 4);
     WAIT(clock_lo, 50, 5);
-    /* stop bit [11] */
+
+    /* Stop bit */
     _delay_us(15);
     data_hi();
-    /* ack [12] */
+
+    /* Ack */
     WAIT(data_lo, 50, 6);
     WAIT(clock_lo, 50, 7);
 
@@ -127,12 +131,12 @@ ERROR:
     return 0;
 }
 
-// Do polling data from keyboard to get response to last command.
 uint8_t ps2_host_recv_response(void)
 {
+    // Command may take 25ms/20ms at most([5]p.46, [3]p.21)
     uint8_t retry = 25;
     while (retry-- && !pbuf_has_data()) {
-        _delay_ms(1);   // without this delay it seems to fall into deadlock
+        _delay_ms(1);
     }
     return pbuf_dequeue();
 }
@@ -188,7 +192,6 @@ static inline void pbuf_enqueue(uint8_t data)
     }
     SREG = sreg;
 }
-
 static inline uint8_t pbuf_dequeue(void)
 {
     uint8_t val = 0;