avionic design with actual uboot and tooling

submodule of avionic design uboot bootloader and with included tools to
get you started , read readme.md and readme-tk1-loader.md

u-boot/arch/powerpc/cpu/mpc8xx/interrupts.c

@@ -0,0 +1,278 @@
+/*
+ * (C) Copyright 2000-2002
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <mpc8xx.h>
+#include <mpc8xx_irq.h>
+#include <asm/processor.h>
+#include <commproc.h>
+
+/************************************************************************/
+
+/*
+ * CPM interrupt vector functions.
+ */
+struct interrupt_action {
+	interrupt_handler_t *handler;
+	void *arg;
+};
+
+static struct interrupt_action cpm_vecs[CPMVEC_NR];
+static struct interrupt_action irq_vecs[NR_IRQS];
+
+static void cpm_interrupt_init (void);
+static void cpm_interrupt (void *regs);
+
+/************************************************************************/
+
+int interrupt_init_cpu (unsigned *decrementer_count)
+{
+	volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
+
+	*decrementer_count = get_tbclk () / CONFIG_SYS_HZ;
+
+	/* disable all interrupts */
+	immr->im_siu_conf.sc_simask = 0;
+
+	/* Configure CPM interrupts */
+	cpm_interrupt_init ();
+
+	return (0);
+}
+
+/************************************************************************/
+
+/*
+ * Handle external interrupts
+ */
+void external_interrupt (struct pt_regs *regs)
+{
+	volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
+	int irq;
+	ulong simask, newmask;
+	ulong vec, v_bit;
+
+	/*
+	 * read the SIVEC register and shift the bits down
+	 * to get the irq number
+	 */
+	vec = immr->im_siu_conf.sc_sivec;
+	irq = vec >> 26;
+	v_bit = 0x80000000UL >> irq;
+
+	/*
+	 * Read Interrupt Mask Register and Mask Interrupts
+	 */
+	simask = immr->im_siu_conf.sc_simask;
+	newmask = simask & (~(0xFFFF0000 >> irq));
+	immr->im_siu_conf.sc_simask = newmask;
+
+	if (!(irq & 0x1)) {		/* External Interrupt ?     */
+		ulong siel;
+
+		/*
+		 * Read Interrupt Edge/Level Register
+		 */
+		siel = immr->im_siu_conf.sc_siel;
+
+		if (siel & v_bit) {	/* edge triggered interrupt ?   */
+			/*
+			 * Rewrite SIPEND Register to clear interrupt
+			 */
+			immr->im_siu_conf.sc_sipend = v_bit;
+		}
+	}
+
+	if (irq_vecs[irq].handler != NULL) {
+		irq_vecs[irq].handler (irq_vecs[irq].arg);
+	} else {
+		printf ("\nBogus External Interrupt IRQ %d Vector %ld\n",
+				irq, vec);
+		/* turn off the bogus interrupt to avoid it from now */
+		simask &= ~v_bit;
+	}
+	/*
+	 * Re-Enable old Interrupt Mask
+	 */
+	immr->im_siu_conf.sc_simask = simask;
+}
+
+/************************************************************************/
+
+/*
+ * CPM interrupt handler
+ */
+static void cpm_interrupt (void *regs)
+{
+	volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
+	uint vec;
+
+	/*
+	 * Get the vector by setting the ACK bit
+	 * and then reading the register.
+	 */
+	immr->im_cpic.cpic_civr = 1;
+	vec = immr->im_cpic.cpic_civr;
+	vec >>= 11;
+
+	if (cpm_vecs[vec].handler != NULL) {
+		(*cpm_vecs[vec].handler) (cpm_vecs[vec].arg);
+	} else {
+		immr->im_cpic.cpic_cimr &= ~(1 << vec);
+		printf ("Masking bogus CPM interrupt vector 0x%x\n", vec);
+	}
+	/*
+	 * After servicing the interrupt,
+	 * we have to remove the status indicator.
+	 */
+	immr->im_cpic.cpic_cisr |= (1 << vec);
+}
+
+/*
+ * The CPM can generate the error interrupt when there is a race
+ * condition between generating and masking interrupts. All we have
+ * to do is ACK it and return. This is a no-op function so we don't
+ * need any special tests in the interrupt handler.
+ */
+static void cpm_error_interrupt (void *dummy)
+{
+}
+
+/************************************************************************/
+/*
+ * Install and free an interrupt handler
+ */
+void irq_install_handler (int vec, interrupt_handler_t * handler,
+						  void *arg)
+{
+	volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
+
+	if ((vec & CPMVEC_OFFSET) != 0) {
+		/* CPM interrupt */
+		vec &= 0xffff;
+		if (cpm_vecs[vec].handler != NULL) {
+			printf ("CPM interrupt 0x%x replacing 0x%x\n",
+				(uint) handler,
+				(uint) cpm_vecs[vec].handler);
+		}
+		cpm_vecs[vec].handler = handler;
+		cpm_vecs[vec].arg = arg;
+		immr->im_cpic.cpic_cimr |= (1 << vec);
+#if 0
+		printf ("Install CPM interrupt for vector %d ==> %p\n",
+			vec, handler);
+#endif
+	} else {
+		/* SIU interrupt */
+		if (irq_vecs[vec].handler != NULL) {
+			printf ("SIU interrupt %d 0x%x replacing 0x%x\n",
+				vec,
+				(uint) handler,
+				(uint) cpm_vecs[vec].handler);
+		}
+		irq_vecs[vec].handler = handler;
+		irq_vecs[vec].arg = arg;
+		immr->im_siu_conf.sc_simask |= 1 << (31 - vec);
+#if 0
+		printf ("Install SIU interrupt for vector %d ==> %p\n",
+			vec, handler);
+#endif
+	}
+}
+
+void irq_free_handler (int vec)
+{
+	volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
+
+	if ((vec & CPMVEC_OFFSET) != 0) {
+		/* CPM interrupt */
+		vec &= 0xffff;
+#if 0
+		printf ("Free CPM interrupt for vector %d ==> %p\n",
+			vec, cpm_vecs[vec].handler);
+#endif
+		immr->im_cpic.cpic_cimr &= ~(1 << vec);
+		cpm_vecs[vec].handler = NULL;
+		cpm_vecs[vec].arg = NULL;
+	} else {
+		/* SIU interrupt */
+#if 0
+		printf ("Free CPM interrupt for vector %d ==> %p\n",
+			vec, cpm_vecs[vec].handler);
+#endif
+		immr->im_siu_conf.sc_simask &= ~(1 << (31 - vec));
+		irq_vecs[vec].handler = NULL;
+		irq_vecs[vec].arg = NULL;
+	}
+}
+
+/************************************************************************/
+
+static void cpm_interrupt_init (void)
+{
+	volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
+
+	/*
+	 * Initialize the CPM interrupt controller.
+	 */
+
+	immr->im_cpic.cpic_cicr =
+		(CICR_SCD_SCC4 |
+		 CICR_SCC_SCC3 |
+		 CICR_SCB_SCC2 |
+		 CICR_SCA_SCC1) | ((CPM_INTERRUPT / 2) << 13) | CICR_HP_MASK;
+
+	immr->im_cpic.cpic_cimr = 0;
+
+	/*
+	 * Install the error handler.
+	 */
+	irq_install_handler (CPMVEC_ERROR, cpm_error_interrupt, NULL);
+
+	immr->im_cpic.cpic_cicr |= CICR_IEN;
+
+	/*
+	 * Install the cpm interrupt handler
+	 */
+	irq_install_handler (CPM_INTERRUPT, cpm_interrupt, NULL);
+}
+
+/************************************************************************/
+
+/*
+ * timer_interrupt - gets called when the decrementer overflows,
+ * with interrupts disabled.
+ * Trivial implementation - no need to be really accurate.
+ */
+void timer_interrupt_cpu (struct pt_regs *regs)
+{
+	volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
+
+#if 0
+	printf ("*** Timer Interrupt *** ");
+#endif
+	/* Reset Timer Expired and Timers Interrupt Status */
+	immr->im_clkrstk.cark_plprcrk = KAPWR_KEY;
+	__asm__ ("nop");
+	/*
+	  Clear TEXPS (and TMIST on older chips). SPLSS (on older
+	  chips) is cleared too.
+
+	  Bitwise OR is a read-modify-write operation so ALL bits
+	  which are cleared by writing `1' would be cleared by
+	  operations like
+
+	  immr->im_clkrst.car_plprcr |= PLPRCR_TEXPS;
+
+	  The same can be achieved by simple writing of the PLPRCR
+	  to itself. If a bit value should be preserved, read the
+	  register, ZERO the bit and write, not OR, the result back.
+	*/
+	immr->im_clkrst.car_plprcr = immr->im_clkrst.car_plprcr;
+}
+
+/************************************************************************/