Changes between Initial Version and Version 1 of xcu_driver

Timestamp:

Oct 8, 2014, 7:23:17 PM (10 years ago)

Author:

alain

Comment:

--

xcu_driver

@@ +1 @@
+= GIET-VM / XCU Driver = 
+
+[[PageOutline]]
+
+The [source:soft/giet_vm/giet_drivers/xcu_driver.c xcu_driver.c] and [source:soft/giet_vm/giet_drivers/xcu_driver.h xcu_driver.h] files define the XCU driver.
+
+The ''vci_xcu'' component is an extended interrupt controller, available in the SoCLib components library, and supporting three types of interrupts:
+ * '''HWI''' : HardWare Interrupts (from hardware peripherals)
+ * '''PTI''' : Programmable Timer Interrupts (contained in the XCU component)
+ * '''WTI''' : Write Trigered Interrupts (from software, or from a PIC controller) 
+
+The GIET-VM uses three 32 entries interrupt vectors (one interrupt vector for each interrupt type).
+
+The CXU component is a replicated peripheral: it must exist one XCU per cluster, and each one can contain several channels:
+The number of XICU channels is equal to NB_PROCS_MAX, because there is one private XCU channel per processor in a cluster.
+
+The virtual base address of the segment associated to the component is:
+    vbase =  SEG_XCU_BASE + cluster_xy * PERI_CLUSTER_INCREMENT
+
+The SEG_XCU_BASE and PERI_CLUSTER_INCREMENT values must be defined in the hard_config.h file.
+
+The addressable registers map is defined [source:soft/giet_vm/giet_drivers/xcu_driver.h here].
+
+ === void '''_xcu_set_mask'''( unsigned int cluster_xy,  unsigned int channel,    unsigned int mask,   unsigned int irq_type ) ===
+This function set the mask register for the IRQ type defined by "irq_type",
+and for the channel identified by the "cluster_xy" and "channel" arguments.
+All '1' bits are set / all '0' bits are not modified.
+
+ === void '''_xcu_get_index'''( unsigned int   cluster_xy,   unsigned int   channel,   unsigned int * index,  unsigned int * irq_type ) ===
+This function returns the index and the type of the highest priority active interrupt:
+1. active PTI (Timer Interrupt),
+2. active HWI (Hardware Interrupt),
+3. active WTI (Software Interrupt)
+
+ === void '''_xcu_send_wti'''( unsigned int cluster_xy,   unsigned int wti_index,   unsigned int wdata ) ===
+This function writes the ''wdata'' value in the mailbox defined by the ''cluster_xy'' and ''wti_inde'' arguments.
+
+ === void '''_xcu_get_wti_value'''( unsigned int   cluster_xy,   unsigned int   wti_index,   unsigned int * value ) ===
+This function returns the value contained in a WTI mailbox defined by the ''cluster_xy'' and ''wti_index'' arguments. This value is written in the ''value'' argument, and the corresponding WTI is acknowledged.
+
+ === void '''_xcu_get_wti_address'''( unsigned int   wti_index,  unsigned int * address ) ===
+This function returns the physical address of the WTI mailbox in cluster [0][0], defined by the ''wti_index'' argument, in the ''address'' argument.
+It is used by the GIET to configurate the IOPIC component. There is no access to a specific XCU component in a specific cluster.
+
+ === void '''_xcu_timer_start'''( unsigned int cluster_xy,   unsigned int pti_index,  unsigned int period ) === 
+This function activates a timer contained in XCU by writing in the proper register the period value.
+
+ === void '''_xcu_timer_stop'''( unsigned int cluster_xy,   unsigned int pti_index ) == 
+This function desactivates a timer in XCU component by writing in the proper register.
+
+ === unsigned int '''_xcu_timer_reset_irq'''( unsigned int cluster_xy,   unsigned int pti_index ) ===
+//////////////////////////////////////////////////////////////////////////////
+// This function acknowlegge a timer interrupt in XCU 
+// component by reading in the proper XCU register.
+// It can be used by both the isr_switch() for a "system" timer, 
+// or by the _isr_timer() for an "user" timer.
+//////////////////////////////////////////////////////////////////////////////
+
+extern void _xcu_timer_reset_cpt( unsigned int cluster_xy, 
+                                  unsigned int pti_index ); 
+//////////////////////////////////////////////////////////////////////////////
+// This function resets a timer counter. To do so, we re-write the period
+// in the proper register, what causes the count to restart.
+// The period value is read from the same (TIMER_PERIOD) register,
+// this is why in appearance we do nothing useful (read a value
+// from a register and write this value in the same register).
+// This function is called during a context switch (user or preemptive)
+/////////////////////////////////////////////////////////////////////////////
+