commit 1dbe354f2931788a7bbf704fa8df3a20ba5c83b2
author Brian Silverman <brians> Thu Oct 31 20:29:11 2013 -0700
committer Brian Silverman <brians> Thu Oct 31 20:29:11 2013 -0700
tree 7689a2145a07ee7f8ea6b61944ac5949d6ca327e
parent 441d55ca03c7aff74178c615117d369fe844a252

worked around a dumb errata

gyro_board/src/usb/CAN.c

diff --git a/gyro_board/src/usb/CAN.c b/gyro_board/src/usb/CAN.c
index 35f811f..61e7f47 100644
--- a/gyro_board/src/usb/CAN.c
+++ b/gyro_board/src/usb/CAN.c
@@ -231,10 +231,6 @@
     vTaskDelete(NULL);
   }
 
-  // Set all of the CAN stuff to run at CCLK/6, which translates to about 1 Mbit
-  // (1.042).
-  SC->PCLKSEL0 |= 3 << 26 | 3 << 28 | 3 << 30;
-
   // Enable CAN
   SC->PCONP |= PCONP_PCCAN1;
 
@@ -279,6 +275,11 @@
   }
 }
 
+void CAN_PCLKSEL(void) {
+  // Set all of the CAN stuff to run at CCLK/6, which translates to about 1 Mbit
+  // (1.042).
+  SC->PCLKSEL0 |= 3 << 26 | 3 << 28 | 3 << 30;
+}
 
 void initCAN(void){
   xTaskCreate(vCAN1, (signed char *) "CAN1rx", configMINIMAL_STACK_SIZE + 400, NULL, tskIDLE_PRIORITY + 1, NULL);

gyro_board/src/usb/CAN.h

diff --git a/gyro_board/src/usb/CAN.h b/gyro_board/src/usb/CAN.h
index 1ef39d5..60f2d10 100644
--- a/gyro_board/src/usb/CAN.h
+++ b/gyro_board/src/usb/CAN.h
@@ -14,6 +14,9 @@
 } can_message;
 
 int CAN_get(can_message *message);
+
+// Sets up PCLKSEL for CAN stuff (errata PCLKSELx.1).
+void CAN_PCLKSEL(void);
 void initCAN(void);
 
 #endif

gyro_board/src/usb/gyro.c

diff --git a/gyro_board/src/usb/gyro.c b/gyro_board/src/usb/gyro.c
index ad49658..40734ff 100644
--- a/gyro_board/src/usb/gyro.c
+++ b/gyro_board/src/usb/gyro.c
@@ -187,10 +187,6 @@
 static portTASK_FUNCTION(gyro_read_task, pvParameters) {
   SC->PCONP |= PCONP_PCSSP0;
 
-  // Make sure that the clock is set up right.
-  SC->PCLKSEL1 &= ~(3 << 10);
-  SC->PCLKSEL1 |= 1 << 10;
-
   // Set up SSEL.
   // It's is just a GPIO pin because we're the master (it would be special if we
   // were a slave).

gyro_board/src/usb/main.c

diff --git a/gyro_board/src/usb/main.c b/gyro_board/src/usb/main.c
index 4e74ce7..e186bba 100644
--- a/gyro_board/src/usb/main.c
+++ b/gyro_board/src/usb/main.c
@@ -149,14 +149,19 @@
 
   setup_PLL1();
 
-  // Set everything to run at full CCLK by default.
-  SC->PCLKSEL0 = 0x55555555;
-
   /* Configure the LEDs. */
   vParTestInitialise();
 }
 
 int main(void) {
+  // Errata PCLKSELx.1 says that we have to do all of this BEFORE setting up
+  // PLL0 or it might not work.
+
+  // Set everything to run at full CCLK by default.
+  SC->PCLKSEL0 = 0x55555555;
+
+  CAN_PCLKSEL();
+
   setup_hardware();
 
   digital_init();
@@ -203,7 +208,6 @@
 
   /* Power up and feed the timer. */
   SC->PCONP |= 0x02UL;
-  SC->PCLKSEL0 = (SC->PCLKSEL0 & (~(0x3 << 2))) | (0x01 << 2);
 
   /* Reset Timer 0 */
   TIM0->TCR = TCR_COUNT_RESET;