Diff: PS2MS_INIT.cpp

Revision:

0:ce15490e89e9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PS2MS_INIT.cpp	Sun Feb 27 23:34:31 2011 +0000
@@ -0,0 +1,249 @@
+/**
+ * PS/2 mouse interface control class (Version 0.0.1)
+ *
+ * Copyright (C) 2010 Shinichiro Nakamura (CuBeatSystems)
+ * http://shinta.main.jp/
+ */
+#include "PS2MS_INIT.h"
+
+/**
+ * Create.
+ */
+PS2MS_INIT::PS2MS_INIT(PinName clk_pin, PinName dat_pin)
+        : clk(clk_pin), dat(dat_pin) {
+    clk.input();
+    dat.input();
+    clk.write(1);
+    dat.write(1);
+
+    /*
+     * 0xFF: Reset command.
+     * 0xF3: Set sample rate.
+     * 0xF2: Read device type.
+     * 0xE8: Set resolution.
+     * 0xE6: Set scaling.
+     * 0xF4: Enable device.
+     */
+    char txdat[17] = "\xFF\xFF\xFF\xF3\xC8\xF3\x64\xF3\x50\xF2\xE8\x03\xE6\xF3\x28\xF4";
+    const int n = sizeof(txdat);
+    int txerrcnt = 0;
+    int rxerrcnt = 0;
+    for (int i = 0; i < n; i++) {
+        if (send(txdat[i]) != 0) {
+            txerrcnt++;
+        }
+        if (recv() < 0) {
+            rxerrcnt++;
+        }
+        if (txdat[i] == 0xF2) {
+            if (recv() < 0) {
+                rxerrcnt++;
+            }
+        }
+        if (txdat[i] == 0xFF) {
+            if (recv() < 0) {
+                rxerrcnt++;
+            }
+            if (recv() < 0) {
+                rxerrcnt++;
+            }
+        }
+    }
+    
+    if (txerrcnt > 0) {
+        // printf("TX %d errors occured.\n", txerrcnt);
+    }
+    if (rxerrcnt > 0) {
+        // printf("RX %d errors occured.\n", rxerrcnt);
+    }
+}
+
+/**
+ * Destroy.
+ */
+PS2MS_INIT::~PS2MS_INIT() {
+}
+
+/**
+ * Send a byte data.
+ *
+ * @param c a character.
+ *
+ * @return Negative value is a error number.
+ */
+int PS2MS_INIT::send(uint8_t c) {
+    clk.output();
+    dat.output();
+
+    clk.write(0);
+    wait_us(200);
+
+    dat.write(0);
+    wait_us(10);
+    clk.write(1);
+    wait_us(10);
+
+    clk.input();
+    int parcnt = 0;
+    for (int i = 0; i < 10; i++) {
+        if (!waitClockDownEdge()) {
+            return -1;
+        }
+        if ((0 <= i) && (i <= 7)) {
+            /*
+             * Data bit.
+             */
+            if ((c & (1 << i)) == 0) {
+                dat.write(0);
+            } else {
+                dat.write(1);
+                parcnt++;
+            }
+        }
+        if (i == 8) {
+            /*
+             * Parity bit.
+             */
+            if ((parcnt % 2) == 0) {
+                dat.write(1);
+            } else {
+                dat.write(0);
+            }
+        }
+        if (i == 9) {
+            /*
+             * Stop bit.
+             */
+            dat.write(1);
+        }
+    }
+    dat.input();
+
+    /*
+     * Check a ACK.
+     */
+    if (!waitClockDownEdge()) {
+        return -2;
+    }
+    if (dat.read() != 0) {
+        return -3;
+    }
+
+    if (!waitClockUpLevel()) {
+        return -4;
+    }
+
+    return 0;
+}
+
+/**
+ * Receive a byte data.
+ *
+ * @return return a data. Negative value is a error number.
+ */
+int PS2MS_INIT::recv(void) {
+    uint8_t c = 0;
+    clk.input();
+    dat.input();
+    int parcnt = 0;
+    for (int i = 0; i < 11; i++) {
+        if (!waitClockDownEdge()) {
+            return -1;
+        }
+        if (i == 0) {
+            /*
+             * Start bit.
+             */
+            if (dat.read() != 0) {
+                return -2;
+            }
+        }
+        if ((1 <= i) && (i <= 8)) {
+            /*
+             * Data bit.
+             */
+            if (dat.read() == 0) {
+                c &= ~(1 << (i - 1));
+            } else {
+                c |= (1 << (i - 1));
+                parcnt++;
+            }
+        }
+        if (i == 9) {
+            /*
+             * Parity bit.
+             */
+            if (dat.read() == 0) {
+                if ((parcnt % 2) != 1) {
+                    return -3;
+                }
+            } else {
+                if ((parcnt % 2) != 0) {
+                    return -4;
+                }
+            }
+        }
+        if (i == 10) {
+            /*
+             * Stop bit.
+             */
+            if (dat.read() != 1) {
+                return -5;
+            }
+        }
+    }
+    return (int)c;
+}
+
+/**
+ * Wait a clock down edge.
+ *
+ * @return true if wait done.
+ */
+bool PS2MS_INIT::waitClockDownEdge(void) {
+    int cnt;
+    /*
+     * Wait until clock is low.
+     */
+    cnt = 0;
+    while (clk.read() == 0) {
+        cnt++;
+        if (MAX_RETRY < cnt) {
+            return false;
+        }
+        wait_us(1);
+    }
+    /*
+     * Wait until clock is high.
+     */
+    cnt = 0;
+    while (clk.read() == 1) {
+        cnt++;
+        if (MAX_RETRY < cnt) {
+            return false;
+        }
+        wait_us(1);
+    }
+    return true;
+}
+
+/**
+ * Wait a clock up level.
+ *
+ * @return true if wait done.
+ */
+bool PS2MS_INIT::waitClockUpLevel(void) {
+    int cnt;
+    /*
+     * Wait until clock is low.
+     */
+    cnt = 0;
+    while (clk.read() == 0) {
+        cnt++;
+        if (MAX_RETRY < cnt) {
+            return false;
+        }
+        wait_us(1);
+    }
+    return true;
+}