summaryrefslogtreecommitdiff
path: root/arch/x86/lib/i8259.c
diff options
context:
space:
mode:
authorBin Meng <bmeng.cn@gmail.com>2015-10-22 19:13:30 -0700
committerBin Meng <bmeng.cn@gmail.com>2015-11-13 06:46:18 -0800
commitda3fe247591e17dead357f05f69124c54aa13a01 (patch)
treeb508cd98120839f343e77980f4c02f8c5b151e0f /arch/x86/lib/i8259.c
parentbffeed0158bc5114a9542ff83c716e352841dcfb (diff)
downloadu-boot-imx-da3fe247591e17dead357f05f69124c54aa13a01.zip
u-boot-imx-da3fe247591e17dead357f05f69124c54aa13a01.tar.gz
u-boot-imx-da3fe247591e17dead357f05f69124c54aa13a01.tar.bz2
x86: Rename pcat_ to i8254 and i8259 accordingly
Rename pcat_timer.c to i8254.c and pcat_interrupts.c to i8259.c, to match their header file names (i8254.h and i8259.h). Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Acked-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'arch/x86/lib/i8259.c')
-rw-r--r--arch/x86/lib/i8259.c129
1 files changed, 129 insertions, 0 deletions
diff --git a/arch/x86/lib/i8259.c b/arch/x86/lib/i8259.c
new file mode 100644
index 0000000..b9d0614
--- /dev/null
+++ b/arch/x86/lib/i8259.c
@@ -0,0 +1,129 @@
+/*
+ * (C) Copyright 2009
+ * Graeme Russ, <graeme.russ@gmail.com>
+ *
+ * (C) Copyright 2002
+ * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+/*
+ * This file provides the interrupt handling functionality for systems
+ * based on the standard PC/AT architecture using two cascaded i8259
+ * Programmable Interrupt Controllers.
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/i8259.h>
+#include <asm/ibmpc.h>
+#include <asm/interrupt.h>
+
+int i8259_init(void)
+{
+ u8 i;
+
+ /* Mask all interrupts */
+ outb(0xff, MASTER_PIC + IMR);
+ outb(0xff, SLAVE_PIC + IMR);
+
+ /*
+ * Master PIC
+ * Place master PIC interrupts at INT20
+ */
+ outb(ICW1_SEL | ICW1_EICW4, MASTER_PIC + ICW1);
+ outb(0x20, MASTER_PIC + ICW2);
+ outb(IR2, MASTER_PIC + ICW3);
+ outb(ICW4_PM, MASTER_PIC + ICW4);
+
+ for (i = 0; i < 8; i++)
+ outb(OCW2_SEOI | i, MASTER_PIC + OCW2);
+
+ /*
+ * Slave PIC
+ * Place slave PIC interrupts at INT28
+ */
+ outb(ICW1_SEL | ICW1_EICW4, SLAVE_PIC + ICW1);
+ outb(0x28, SLAVE_PIC + ICW2);
+ outb(0x02, SLAVE_PIC + ICW3);
+ outb(ICW4_PM, SLAVE_PIC + ICW4);
+
+ for (i = 0; i < 8; i++)
+ outb(OCW2_SEOI | i, SLAVE_PIC + OCW2);
+
+ /*
+ * Enable cascaded interrupts by unmasking the cascade IRQ pin of
+ * the master PIC
+ */
+ unmask_irq(2);
+
+ /* Interrupt 9 should be level triggered (SCI). The OS might do this */
+ configure_irq_trigger(9, true);
+
+ return 0;
+}
+
+void mask_irq(int irq)
+{
+ int imr_port;
+
+ if (irq >= SYS_NUM_IRQS)
+ return;
+
+ if (irq > 7)
+ imr_port = SLAVE_PIC + IMR;
+ else
+ imr_port = MASTER_PIC + IMR;
+
+ outb(inb(imr_port) | (1 << (irq & 7)), imr_port);
+}
+
+void unmask_irq(int irq)
+{
+ int imr_port;
+
+ if (irq >= SYS_NUM_IRQS)
+ return;
+
+ if (irq > 7)
+ imr_port = SLAVE_PIC + IMR;
+ else
+ imr_port = MASTER_PIC + IMR;
+
+ outb(inb(imr_port) & ~(1 << (irq & 7)), imr_port);
+}
+
+void specific_eoi(int irq)
+{
+ if (irq >= SYS_NUM_IRQS)
+ return;
+
+ if (irq > 7) {
+ /*
+ * IRQ is on the slave - Issue a corresponding EOI to the
+ * slave PIC and an EOI for IRQ2 (the cascade interrupt)
+ * on the master PIC
+ */
+ outb(OCW2_SEOI | (irq & 7), SLAVE_PIC + OCW2);
+ irq = SEOI_IR2;
+ }
+
+ outb(OCW2_SEOI | irq, MASTER_PIC + OCW2);
+}
+
+void configure_irq_trigger(int int_num, bool is_level_triggered)
+{
+ u16 int_bits = inb(ELCR1) | (((u16)inb(ELCR2)) << 8);
+
+ debug("%s: current interrupts are 0x%x\n", __func__, int_bits);
+ if (is_level_triggered)
+ int_bits |= (1 << int_num);
+ else
+ int_bits &= ~(1 << int_num);
+
+ /* Write new values */
+ debug("%s: try to set interrupts 0x%x\n", __func__, int_bits);
+ outb((u8)(int_bits & 0xff), ELCR1);
+ outb((u8)(int_bits >> 8), ELCR2);
+}