[iQue] Decompile errorled.c, GPIO register defines (#74)

* Decompile errorled.c, GPIO register defines * LED_OFF <-> LED_ON * RTC doc * Correct GPIO
decompals · Nov 28, 2024 · a06d8de · a06d8de
1 parent ee9fd71
commit a06d8de
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Showing 6 changed files with 159 additions and 45 deletions.
diff --git a/include/PR/bcp.h b/include/PR/bcp.h
@@ -70,10 +70,58 @@
 //! ?
 #define PI_5C_REG (PI_BASE_REG + 0x5C)
 
-
-
-//! PI_MISC_REG ?
-#define PI_60_REG (PI_BASE_REG + 0x60)
+/**
+ * [31:16] Box ID
+ *   [31:30] ?? (osInitialize checks this and sets __osBbIsBb to 2 if != 0)
+ *   [29:27] ?? (unused so far)
+ *   [26:25] ?? (system clock speed identifier?)
+ *   [24:22] ?? (bootrom, checked against MI_10_REG and copied there if mismatch)
+ *   [21:16] ?? (unused so far)
+ * [ 7: 4] GPIO direction control
+ *     [7] RTC Data output enable
+ *     [6] RTC Clock output enable
+ *     [5] Error LED output enable
+ *     [4] Power Control output enable
+ * [ 3: 0] GPIO in/out value
+ *     [3] RTC Data output value (0=low, 1=high)
+ *     [2] RTC Clock output value (0=low, 1=high)
+ *     [1] Error LED (0=on, 1=off)
+ *     [0] Power Control (0=off, 1=on)
+ */
+#define PI_GPIO_REG (PI_BASE_REG + 0x60)
+
+/* Box ID */
+#define PI_GPIO_GET_BOXID(reg)  ((reg) >> 16)
+#define PI_GPIO_BOXID_MASK_30_31    (3 << 30)
+
+/* Input/Output enables */
+#define PI_GPIO_I_PWR       ((0 << 0) << 4)
+#define PI_GPIO_O_PWR       ((1 << 0) << 4)
+#define PI_GPIO_I_LED       ((0 << 1) << 4)
+#define PI_GPIO_O_LED       ((1 << 1) << 4)
+#define PI_GPIO_I_RTC_CLK   ((0 << 2) << 4)
+#define PI_GPIO_O_RTC_CLK   ((1 << 2) << 4)
+#define PI_GPIO_I_RTC_DAT   ((0 << 3) << 4)
+#define PI_GPIO_O_RTC_DAT   ((1 << 3) << 4)
+
+/* Output controls */
+/* Power */
+#define PI_GPIO_PWR_OFF     (0 << 0)
+#define PI_GPIO_PWR_ON      (1 << 0)
+/* LED */
+#define PI_GPIO_LED_ON      (0 << 1)
+#define PI_GPIO_LED_OFF     (1 << 1)
+/* RTC */
+#define PI_GPIO_RTC_CLK_LO  (0 << 2)
+#define PI_GPIO_RTC_CLK_HI  (1 << 2)
+#define PI_GPIO_RTC_DAT_LO  (0 << 3)
+#define PI_GPIO_RTC_DAT_HI  (1 << 3)
+
+/* Input getters */
+#define PI_GPIO_GET_PWR(reg)        (((reg) >> 0) & 1)
+#define PI_GPIO_GET_LED(reg)        (((reg) >> 1) & 1)
+#define PI_GPIO_GET_RTC_CLK(reg)    (((reg) >> 2) & 1)
+#define PI_GPIO_GET_RTC_DAT(reg)    (((reg) >> 3) & 1)
 
 
 

diff --git a/src/bb/misc/boxid.c b/src/bb/misc/boxid.c
@@ -2,5 +2,5 @@
 #include "PR/bcp.h"
 
 u32 osBbGetBoxId(void) {
-    return IO_READ(PI_60_REG) >> 0x10;
+    return PI_GPIO_GET_BOXID(IO_READ(PI_GPIO_REG));
 }
diff --git a/src/bb/misc/errorled.c b/src/bb/misc/errorled.c
@@ -0,0 +1,14 @@
+#include "PR/os_internal.h"
+#include "PR/bcp.h"
+
+void osBbSetErrorLed(u32 value) {
+    u32 mask = IO_READ(PI_GPIO_REG);
+    mask &= ~PI_GPIO_LED_OFF;
+    mask &= ~PI_GPIO_O_LED;
+    IO_WRITE(PI_GPIO_REG, mask | ((value == 0) ? PI_GPIO_LED_OFF : PI_GPIO_LED_ON) | PI_GPIO_O_LED);
+}
+
+u32 osBbGetErrorLed(void) {
+    u32 v = PI_GPIO_GET_LED(IO_READ(PI_GPIO_REG));
+    return v;
+}
diff --git a/src/bb/misc/power.c b/src/bb/misc/power.c
@@ -2,11 +2,9 @@
 #include "PR/bcp.h"
 
 void osBbPowerOn(void) {
-    // Power control = 1, Power mask = 1
-    IO_WRITE(PI_60_REG, 0x11);
+    IO_WRITE(PI_GPIO_REG, PI_GPIO_O_PWR | PI_GPIO_PWR_ON);
 }
 
 void osBbPowerOff(void) {
-    // Power control = 0, Power mask = 1
-    IO_WRITE(PI_60_REG, 0x10);
+    IO_WRITE(PI_GPIO_REG, PI_GPIO_O_PWR | PI_GPIO_PWR_OFF);
 }
diff --git a/src/bb/misc/rtc.c b/src/bb/misc/rtc.c
@@ -2,95 +2,149 @@
 #include "bcp.h"
 #include "macros.h"
 
+#define RTC_MASK ((PI_GPIO_O_RTC_DAT | PI_GPIO_RTC_DAT_HI) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_HI))
+
+#define RTC_ADDR 0xD0
+#define RTC_WR   0
+#define RTC_RD   1
+
 void __osBbDelay(u32 usec);
 
 static void write_rtc(u32 x) {
-    IO_WRITE(PI_60_REG, x);
+    IO_WRITE(PI_GPIO_REG, x);
     __osBbDelay(2);
 }
 
 static void send_start(u8 write) {
     u32 i;
     u32 j;
-    u32 mask = IO_READ(PI_60_REG) & ~0xCC;
+    u32 mask = IO_READ(PI_GPIO_REG) & ~RTC_MASK;
     u8 byte[2];
 
-    byte[0] = (!write) ? 0xD1 : 0xD0;
+    byte[0] = (!write) ? (RTC_ADDR | RTC_RD) : (RTC_ADDR | RTC_WR);
     byte[1] = 0;
 
-    write_rtc(mask | 0xC4);
-    write_rtc(mask | 0xC0);
+    // Send start signal (DAT HIGH -> LOW while CLK HIGH) assuming both CLK and DAT were initially HIGH
+    // Cyc -1 | 0 | 1
+    // CLK ‾‾‾|‾‾‾|___
+    // DAT ‾‾‾|___|___
+    write_rtc(mask | (PI_GPIO_O_RTC_DAT | PI_GPIO_RTC_DAT_LO) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_HI));
+    write_rtc(mask | (PI_GPIO_O_RTC_DAT | PI_GPIO_RTC_DAT_LO) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_LO));
 
     for (i = 0; i < write + 1; i++) {
+        // Send address in byte[0], for writes also send word address in byte[1]
         for (j = 0; j < 8; j++) {
-            u32 b = ((byte[i] >> (7 - j)) & 1) ? 8 : 0;
-
-            write_rtc(mask | (0x80 | b) | 0x40);
-            write_rtc(mask | (0x80 | b) | 0x44);
-            write_rtc(mask | (0x80 | b) | 0x40);
+            u32 b = ((byte[i] >> (7 - j)) & 1) ? PI_GPIO_RTC_DAT_HI : PI_GPIO_RTC_DAT_LO;
+
+            // Transmit single bit to the RTC
+            // Cyc  0 | 1 | 2
+            // CLK ___|‾‾‾|___
+            // DAT  b | b | b
+            write_rtc(mask | (PI_GPIO_O_RTC_DAT | b) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_LO));
+            write_rtc(mask | (PI_GPIO_O_RTC_DAT | b) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_HI));
+            write_rtc(mask | (PI_GPIO_O_RTC_DAT | b) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_LO));
         }
-        write_rtc(mask | 0x40);
-        write_rtc(mask | 0x44);
+
+        // Toggle CLK to receive ACK from the RTC, but don't read it
+        // Cyc  0 | 1
+        // CLK ___|‾‾‾
+        // DAT  x | x
+        write_rtc(mask | PI_GPIO_I_RTC_DAT | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_LO));
+        write_rtc(mask | PI_GPIO_I_RTC_DAT | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_HI));
     }
-    write_rtc(mask | 0x40);
+
+    // End on CLK LOW
+    // Cyc  0
+    // CLK ___
+    // DAT  x
+    write_rtc(mask | PI_GPIO_I_RTC_DAT | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_LO));
 }
 
 static void send_stop(void) {
-    u32 mask = IO_READ(PI_60_REG) & ~0xCC;
-    write_rtc(mask | 0x80 | 0x40);
-    write_rtc(mask | 0x80 | 0x44);
-    write_rtc(mask | 0x80 | 0x4C);
+    u32 mask = IO_READ(PI_GPIO_REG) & ~RTC_MASK;
+
+    // Send stop signal (DAT LOW -> HIGH while CLK HIGH)
+    // Cyc  0 | 1 | 2
+    // CLK ___|‾‾‾|‾‾‾
+    // DAT ___|___|‾‾‾
+    write_rtc(mask | (PI_GPIO_O_RTC_DAT | PI_GPIO_RTC_DAT_LO) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_LO));
+    write_rtc(mask | (PI_GPIO_O_RTC_DAT | PI_GPIO_RTC_DAT_LO) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_HI));
+    write_rtc(mask | (PI_GPIO_O_RTC_DAT | PI_GPIO_RTC_DAT_HI) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_HI));
 }
 
 static void read_bytes(u8* bytes, u8 len) {
     u32 ack;
     u32 i;
-    u32 mask = IO_READ(PI_60_REG) & ~0xCC;
+    u32 mask = IO_READ(PI_GPIO_REG) & ~RTC_MASK;
 
     while (len-- > 0) {
         u32 x = 0;
 
+        // Read 1 byte
         for (i = 0; i < 8; i++) {
-            write_rtc(mask | 0x40);
-            write_rtc(mask | 0x44);
+            // Toggle CLK to receive the bit from the RTC
+            // Cyc  0 | 1
+            // CLK ___|‾‾‾
+            // DAT  x | x
+            write_rtc(mask | PI_GPIO_I_RTC_DAT | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_LO));
+            write_rtc(mask | PI_GPIO_I_RTC_DAT | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_HI));
+
+            // Read the bit sent by the RTC
             x <<= 1;
-            x |= (IO_READ(PI_60_REG) >> 3) & 1;
+            x |= PI_GPIO_GET_RTC_DAT(IO_READ(PI_GPIO_REG));
         }
         *(bytes++) = x;
 
-        ack = (len == 0) ? 0x88 : 0x80;
+        ack = (len == 0) ? (PI_GPIO_O_RTC_DAT | PI_GPIO_RTC_DAT_HI) : (PI_GPIO_O_RTC_DAT | PI_GPIO_RTC_DAT_LO);
 
-        write_rtc(mask | 0x40 | 0x80);
-        write_rtc(mask | 0x44 | ack);
+        // Send ACK or NACK, DAT HIGH is NACK while DAT LOW is ACK. NACK is sent at th end.
+        // Cyc  0 | 1
+        // CLK ___|‾‾‾
+        // DAT ___| a
+        write_rtc(mask | (PI_GPIO_O_RTC_DAT | PI_GPIO_RTC_DAT_LO) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_LO));
+        write_rtc(mask | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_HI) | ack);
     }
     send_stop();
 }
 
 static void write_bytes(u8* bytes, u8 len) {
     u32 i;
-    u32 mask = IO_READ(PI_60_REG) & ~0xCC;
+    u32 mask = IO_READ(PI_GPIO_REG) & ~RTC_MASK;
 
     while (len-- > 0) {
         u32 x = *(bytes++);
 
         for (i = 0; i < 8; i++) {
-            u32 b = (x & 0x80) ? 8 : 0;
-
-            write_rtc(mask | (0x80 | b) | 0x40);
-            write_rtc(mask | (0x80 | b) | 0x44);
-            write_rtc(mask | (0x80 | b) | 0x44);
+            u32 b = (x & 0x80) ? PI_GPIO_RTC_DAT_HI : PI_GPIO_RTC_DAT_LO;
+
+            // Transmit single bit to the RTC
+            // Cyc  0 | 1 | 2
+            // CLK ___|‾‾‾|‾‾‾
+            // DAT  b | b | b
+            write_rtc(mask | (PI_GPIO_O_RTC_DAT | b) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_LO));
+            write_rtc(mask | (PI_GPIO_O_RTC_DAT | b) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_HI));
+            write_rtc(mask | (PI_GPIO_O_RTC_DAT | b) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_HI));
             x <<= 1;
         }
-        write_rtc(mask | 0x40);
-        write_rtc(mask | 0x44);
-        IO_READ(PI_60_REG);
-        write_rtc(mask | 0x40);
+
+        // Toggle CLK to receive ACK from the RTC, read but don't check?
+        // Cyc  0 | 1 | 2 | 3
+        // CLK ___|‾‾‾|‾‾‾|___
+        // DAT  x | x | x | x
+        write_rtc(mask | PI_GPIO_I_RTC_DAT | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_LO));
+        write_rtc(mask | PI_GPIO_I_RTC_DAT | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_HI));
+        IO_READ(PI_GPIO_REG);
+        write_rtc(mask | PI_GPIO_I_RTC_DAT | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_LO));
     }
     send_stop();
 }
 
 void osBbRtcInit(void) {
-    write_rtc(IO_READ(PI_60_REG) | 0xCC);
+    // Set line state to idle (both CLK and DAT HIGH)
+    // Cyc  0
+    // CLK ‾‾‾
+    // DAT ‾‾‾
+    write_rtc(IO_READ(PI_GPIO_REG) | (PI_GPIO_O_RTC_DAT | PI_GPIO_RTC_DAT_HI) | (PI_GPIO_O_RTC_CLK | PI_GPIO_RTC_CLK_HI));
 }
 
 void osBbRtcSet(u8 year, u8 month, u8 day, u8 dow, u8 hour, u8 min, u8 sec) {

diff --git a/src/os/initialize.c b/src/os/initialize.c
@@ -106,7 +106,7 @@ void INITIALIZE_FUNC() {
     }
 
     if (__osBbIsBb) {
-        if (IO_READ(PI_60_REG) & 0xC0000000) {
+        if (IO_READ(PI_GPIO_REG) & PI_GPIO_BOXID_MASK_30_31) {
             __osBbIsBb = 2;
         }
     }