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-rw-r--r--arch/m68knommu/platform/coldfire/intc.c153
1 files changed, 153 insertions, 0 deletions
diff --git a/arch/m68knommu/platform/coldfire/intc.c b/arch/m68knommu/platform/coldfire/intc.c
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+++ b/arch/m68knommu/platform/coldfire/intc.c
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+/*
+ * intc.c -- support for the old ColdFire interrupt controller
+ *
+ * (C) Copyright 2009, Greg Ungerer <gerg@snapgear.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <asm/traps.h>
+#include <asm/coldfire.h>
+#include <asm/mcfsim.h>
+
+/*
+ * The mapping of irq number to a mask register bit is not one-to-one.
+ * The irq numbers are either based on "level" of interrupt or fixed
+ * for an autovector-able interrupt. So we keep a local data structure
+ * that maps from irq to mask register. Not all interrupts will have
+ * an IMR bit.
+ */
+unsigned char mcf_irq2imr[NR_IRQS];
+
+/*
+ * Define the miniumun and maximum external interrupt numbers.
+ * This is also used as the "level" interrupt numbers.
+ */
+#define EIRQ1 25
+#define EIRQ7 31
+
+/*
+ * In the early version 2 core ColdFire parts the IMR register was 16 bits
+ * in size. Version 3 (and later version 2) core parts have a 32 bit
+ * sized IMR register. Provide some size independant methods to access the
+ * IMR register.
+ */
+#ifdef MCFSIM_IMR_IS_16BITS
+
+void mcf_setimr(int index)
+{
+ u16 imr;
+ imr = __raw_readw(MCF_MBAR + MCFSIM_IMR);
+ __raw_writew(imr | (0x1 << index), MCF_MBAR + MCFSIM_IMR);
+}
+
+void mcf_clrimr(int index)
+{
+ u16 imr;
+ imr = __raw_readw(MCF_MBAR + MCFSIM_IMR);
+ __raw_writew(imr & ~(0x1 << index), MCF_MBAR + MCFSIM_IMR);
+}
+
+void mcf_maskimr(unsigned int mask)
+{
+ u16 imr;
+ imr = __raw_readw(MCF_MBAR + MCFSIM_IMR);
+ imr |= mask;
+ __raw_writew(imr, MCF_MBAR + MCFSIM_IMR);
+}
+
+#else
+
+void mcf_setimr(int index)
+{
+ u32 imr;
+ imr = __raw_readl(MCF_MBAR + MCFSIM_IMR);
+ __raw_writel(imr | (0x1 << index), MCF_MBAR + MCFSIM_IMR);
+}
+
+void mcf_clrimr(int index)
+{
+ u32 imr;
+ imr = __raw_readl(MCF_MBAR + MCFSIM_IMR);
+ __raw_writel(imr & ~(0x1 << index), MCF_MBAR + MCFSIM_IMR);
+}
+
+void mcf_maskimr(unsigned int mask)
+{
+ u32 imr;
+ imr = __raw_readl(MCF_MBAR + MCFSIM_IMR);
+ imr |= mask;
+ __raw_writel(imr, MCF_MBAR + MCFSIM_IMR);
+}
+
+#endif
+
+/*
+ * Interrupts can be "vectored" on the ColdFire cores that support this old
+ * interrupt controller. That is, the device raising the interrupt can also
+ * supply the vector number to interrupt through. The AVR register of the
+ * interrupt controller enables or disables this for each external interrupt,
+ * so provide generic support for this. Setting this up is out-of-band for
+ * the interrupt system API's, and needs to be done by the driver that
+ * supports this device. Very few devices actually use this.
+ */
+void mcf_autovector(int irq)
+{
+#ifdef MCFSIM_AVR
+ if ((irq >= EIRQ1) && (irq <= EIRQ7)) {
+ u8 avec;
+ avec = __raw_readb(MCF_MBAR + MCFSIM_AVR);
+ avec |= (0x1 << (irq - EIRQ1 + 1));
+ __raw_writeb(avec, MCF_MBAR + MCFSIM_AVR);
+ }
+#endif
+}
+
+static void intc_irq_mask(unsigned int irq)
+{
+ if (mcf_irq2imr[irq])
+ mcf_setimr(mcf_irq2imr[irq]);
+}
+
+static void intc_irq_unmask(unsigned int irq)
+{
+ if (mcf_irq2imr[irq])
+ mcf_clrimr(mcf_irq2imr[irq]);
+}
+
+static int intc_irq_set_type(unsigned int irq, unsigned int type)
+{
+ return 0;
+}
+
+static struct irq_chip intc_irq_chip = {
+ .name = "CF-INTC",
+ .mask = intc_irq_mask,
+ .unmask = intc_irq_unmask,
+ .set_type = intc_irq_set_type,
+};
+
+void __init init_IRQ(void)
+{
+ int irq;
+
+ init_vectors();
+ mcf_maskimr(0xffffffff);
+
+ for (irq = 0; (irq < NR_IRQS); irq++) {
+ irq_desc[irq].status = IRQ_DISABLED;
+ irq_desc[irq].action = NULL;
+ irq_desc[irq].depth = 1;
+ irq_desc[irq].chip = &intc_irq_chip;
+ intc_irq_set_type(irq, 0);
+ }
+}
+