patch-2.4.22 linux-2.4.22/arch/mips/momentum/ocelot_c/uart-irq.c

• Lines: 149
• Date: 2003-08-25 04:44:40.000000000 -0700
• Orig file: linux-2.4.21/arch/mips/momentum/ocelot_c/uart-irq.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.21/arch/mips/momentum/ocelot_c/uart-irq.c linux-2.4.22/arch/mips/momentum/ocelot_c/uart-irq.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright 2002 Momentum Computer
+ * Author: mdharm@momenco.com
+ *
+ * arch/mips/momentum/ocelot_c/uart-irq.c
+ *     Interrupt routines for UARTs.  Interrupt numbers are assigned from
+ *     80 to 81 (2 interrupt sources).
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <asm/ptrace.h>
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/kernel_stat.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include "ocelot_c_fpga.h"
+
+static inline int ls1bit8(unsigned int x)
+{
+        int b = 7, s;
+
+        s =  4; if (((unsigned char)(x << 4)) == 0) s = 0; b -= s; x <<= s;
+        s =  2; if (((unsigned char)(x << 2)) == 0) s = 0; b -= s; x <<= s;
+        s =  1; if (((unsigned char)(x << 1)) == 0) s = 0; b -= s;
+
+        return b;
+}
+
+/* mask off an interrupt -- 0 is enable, 1 is disable */
+static inline void mask_uart_irq(unsigned int irq)
+{
+	uint8_t value;
+
+	value = OCELOT_FPGA_READ(UART_INTMASK);
+	value |= 1 << (irq - 74);
+	OCELOT_FPGA_WRITE(value, UART_INTMASK);
+
+	/* read the value back to assure that it's really been written */
+	value = OCELOT_FPGA_READ(UART_INTMASK);
+}
+
+/* unmask an interrupt -- 0 is enable, 1 is disable */
+static inline void unmask_uart_irq(unsigned int irq)
+{
+	uint8_t value;
+
+	value = OCELOT_FPGA_READ(UART_INTMASK);
+	value &= ~(1 << (irq - 74));
+	OCELOT_FPGA_WRITE(value, UART_INTMASK);
+
+	/* read the value back to assure that it's really been written */
+	value = OCELOT_FPGA_READ(UART_INTMASK);
+}
+
+/*
+ * Enables the IRQ in the FPGA
+ */
+static void enable_uart_irq(unsigned int irq)
+{
+	unmask_uart_irq(irq);
+}
+
+/*
+ * Initialize the IRQ in the FPGA
+ */
+static unsigned int startup_uart_irq(unsigned int irq)
+{
+	unmask_uart_irq(irq);
+	return 0;
+}
+
+/*
+ * Disables the IRQ in the FPGA
+ */
+static void disable_uart_irq(unsigned int irq)
+{
+	mask_uart_irq(irq);
+}
+
+/*
+ * Masks and ACKs an IRQ
+ */
+static void mask_and_ack_uart_irq(unsigned int irq)
+{
+	mask_uart_irq(irq);
+}
+
+/*
+ * End IRQ processing
+ */
+static void end_uart_irq(unsigned int irq)
+{
+	if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+		unmask_uart_irq(irq);
+}
+
+/*
+ * Interrupt handler for interrupts coming from the FPGA chip.
+ */
+void ll_uart_irq(struct pt_regs *regs)
+{
+	unsigned int irq_src, irq_mask;
+
+	/* read the interrupt status registers */
+	irq_src = OCELOT_FPGA_READ(UART_INTSTAT);
+	irq_mask = OCELOT_FPGA_READ(UART_INTMASK);
+
+	/* mask for just the interrupts we want */
+	irq_src &= ~irq_mask;
+
+	do_IRQ(ls1bit8(irq_src) + 74, regs);
+}
+
+#define shutdown_uart_irq	disable_uart_irq
+
+struct hw_interrupt_type uart_irq_type = {
+	"UART/FPGA",
+	startup_uart_irq,
+	shutdown_uart_irq,
+	enable_uart_irq,
+	disable_uart_irq,
+	mask_and_ack_uart_irq,
+	end_uart_irq,
+	NULL
+};
+
+void uart_irq_init(void)
+{
+	/* Reset irq handlers pointers to NULL */
+	irq_desc[80].status = IRQ_DISABLED;
+	irq_desc[80].action = 0;
+	irq_desc[80].depth = 2;
+	irq_desc[80].handler = &uart_irq_type;
+
+	irq_desc[81].status = IRQ_DISABLED;
+	irq_desc[81].action = 0;
+	irq_desc[81].depth = 2;
+	irq_desc[81].handler = &uart_irq_type;
+}