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-rw-r--r--arch/m68k/amiga/cia.c195
1 files changed, 195 insertions, 0 deletions
diff --git a/arch/m68k/amiga/cia.c b/arch/m68k/amiga/cia.c
new file mode 100644
index 000000000..b9aee983e
--- /dev/null
+++ b/arch/m68k/amiga/cia.c
@@ -0,0 +1,195 @@
+/*
+ * linux/arch/m68k/amiga/cia.c - CIA support
+ *
+ * Copyright (C) 1996 Roman Zippel
+ *
+ * The concept of some functions bases on the original Amiga OS function
+ *
+ * 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/kernel.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/kernel_stat.h>
+#include <linux/init.h>
+#include <linux/seq_file.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+
+#include <asm/irq.h>
+#include <asm/amigahw.h>
+#include <asm/amigaints.h>
+
+struct ciabase {
+ volatile struct CIA *cia;
+ unsigned char icr_mask, icr_data;
+ unsigned short int_mask;
+ int handler_irq, cia_irq, server_irq;
+ char *name;
+} ciaa_base = {
+ .cia = &ciaa,
+ .int_mask = IF_PORTS,
+ .handler_irq = IRQ_AMIGA_PORTS,
+ .cia_irq = IRQ_AMIGA_CIAA,
+ .name = "CIAA"
+}, ciab_base = {
+ .cia = &ciab,
+ .int_mask = IF_EXTER,
+ .handler_irq = IRQ_AMIGA_EXTER,
+ .cia_irq = IRQ_AMIGA_CIAB,
+ .name = "CIAB"
+};
+
+/*
+ * Cause or clear CIA interrupts, return old interrupt status.
+ */
+
+unsigned char cia_set_irq(struct ciabase *base, unsigned char mask)
+{
+ unsigned char old;
+
+ old = (base->icr_data |= base->cia->icr);
+ if (mask & CIA_ICR_SETCLR)
+ base->icr_data |= mask;
+ else
+ base->icr_data &= ~mask;
+ if (base->icr_data & base->icr_mask)
+ amiga_custom.intreq = IF_SETCLR | base->int_mask;
+ return old & base->icr_mask;
+}
+
+/*
+ * Enable or disable CIA interrupts, return old interrupt mask,
+ */
+
+unsigned char cia_able_irq(struct ciabase *base, unsigned char mask)
+{
+ unsigned char old;
+
+ old = base->icr_mask;
+ base->icr_data |= base->cia->icr;
+ base->cia->icr = mask;
+ if (mask & CIA_ICR_SETCLR)
+ base->icr_mask |= mask;
+ else
+ base->icr_mask &= ~mask;
+ base->icr_mask &= CIA_ICR_ALL;
+ if (base->icr_data & base->icr_mask)
+ amiga_custom.intreq = IF_SETCLR | base->int_mask;
+ return old;
+}
+
+static irqreturn_t cia_handler(int irq, void *dev_id)
+{
+ struct ciabase *base = dev_id;
+ int mach_irq;
+ unsigned char ints;
+ unsigned long flags;
+
+ /* Interrupts get disabled while the timer irq flag is cleared and
+ * the timer interrupt serviced.
+ */
+ mach_irq = base->cia_irq;
+ local_irq_save(flags);
+ ints = cia_set_irq(base, CIA_ICR_ALL);
+ amiga_custom.intreq = base->int_mask;
+ if (ints & 1)
+ generic_handle_irq(mach_irq);
+ local_irq_restore(flags);
+ mach_irq++, ints >>= 1;
+ for (; ints; mach_irq++, ints >>= 1) {
+ if (ints & 1)
+ generic_handle_irq(mach_irq);
+ }
+ return IRQ_HANDLED;
+}
+
+static void cia_irq_enable(struct irq_data *data)
+{
+ unsigned int irq = data->irq;
+ unsigned char mask;
+
+ if (irq >= IRQ_AMIGA_CIAB) {
+ mask = 1 << (irq - IRQ_AMIGA_CIAB);
+ cia_set_irq(&ciab_base, mask);
+ cia_able_irq(&ciab_base, CIA_ICR_SETCLR | mask);
+ } else {
+ mask = 1 << (irq - IRQ_AMIGA_CIAA);
+ cia_set_irq(&ciaa_base, mask);
+ cia_able_irq(&ciaa_base, CIA_ICR_SETCLR | mask);
+ }
+}
+
+static void cia_irq_disable(struct irq_data *data)
+{
+ unsigned int irq = data->irq;
+
+ if (irq >= IRQ_AMIGA_CIAB)
+ cia_able_irq(&ciab_base, 1 << (irq - IRQ_AMIGA_CIAB));
+ else
+ cia_able_irq(&ciaa_base, 1 << (irq - IRQ_AMIGA_CIAA));
+}
+
+static struct irq_chip cia_irq_chip = {
+ .name = "cia",
+ .irq_enable = cia_irq_enable,
+ .irq_disable = cia_irq_disable,
+};
+
+/*
+ * Override auto irq 2 & 6 and use them as general chain
+ * for external interrupts, we link the CIA interrupt sources
+ * into this chain.
+ */
+
+static void auto_irq_enable(struct irq_data *data)
+{
+ switch (data->irq) {
+ case IRQ_AUTO_2:
+ amiga_custom.intena = IF_SETCLR | IF_PORTS;
+ break;
+ case IRQ_AUTO_6:
+ amiga_custom.intena = IF_SETCLR | IF_EXTER;
+ break;
+ }
+}
+
+static void auto_irq_disable(struct irq_data *data)
+{
+ switch (data->irq) {
+ case IRQ_AUTO_2:
+ amiga_custom.intena = IF_PORTS;
+ break;
+ case IRQ_AUTO_6:
+ amiga_custom.intena = IF_EXTER;
+ break;
+ }
+}
+
+static struct irq_chip auto_irq_chip = {
+ .name = "auto",
+ .irq_enable = auto_irq_enable,
+ .irq_disable = auto_irq_disable,
+};
+
+void __init cia_init_IRQ(struct ciabase *base)
+{
+ m68k_setup_irq_controller(&cia_irq_chip, handle_simple_irq,
+ base->cia_irq, CIA_IRQS);
+
+ /* clear any pending interrupt and turn off all interrupts */
+ cia_set_irq(base, CIA_ICR_ALL);
+ cia_able_irq(base, CIA_ICR_ALL);
+
+ /* override auto int and install CIA handler */
+ m68k_setup_irq_controller(&auto_irq_chip, handle_simple_irq,
+ base->handler_irq, 1);
+ m68k_irq_startup_irq(base->handler_irq);
+ if (request_irq(base->handler_irq, cia_handler, IRQF_SHARED,
+ base->name, base))
+ pr_err("Couldn't register %s interrupt\n", base->name);
+}