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-rw-r--r--arch/sh/boards/mach-dreamcast/irq.c192
1 files changed, 88 insertions, 104 deletions
diff --git a/arch/sh/boards/mach-dreamcast/irq.c b/arch/sh/boards/mach-dreamcast/irq.c
index 67bdc33dd411..f55fc8e795e9 100644
--- a/arch/sh/boards/mach-dreamcast/irq.c
+++ b/arch/sh/boards/mach-dreamcast/irq.c
@@ -10,106 +10,90 @@
*/
#include <linux/irq.h>
-#include <asm/io.h>
+#include <linux/io.h>
#include <asm/irq.h>
#include <mach/sysasic.h>
-/* Dreamcast System ASIC Hardware Events -
-
- The Dreamcast's System ASIC (a.k.a. Holly) is responsible for receiving
- hardware events from system peripherals and triggering an SH7750 IRQ.
- Hardware events can trigger IRQs 13, 11, or 9 depending on which bits are
- set in the Event Mask Registers (EMRs). When a hardware event is
- triggered, it's corresponding bit in the Event Status Registers (ESRs)
- is set, and that bit should be rewritten to the ESR to acknowledge that
- event.
-
- There are three 32-bit ESRs located at 0xa05f8900 - 0xa05f6908. Event
- types can be found in include/asm-sh/dreamcast/sysasic.h. There are three
- groups of EMRs that parallel the ESRs. Each EMR group corresponds to an
- IRQ, so 0xa05f6910 - 0xa05f6918 triggers IRQ 13, 0xa05f6920 - 0xa05f6928
- triggers IRQ 11, and 0xa05f6930 - 0xa05f6938 triggers IRQ 9.
-
- In the kernel, these events are mapped to virtual IRQs so that drivers can
- respond to them as they would a normal interrupt. In order to keep this
- mapping simple, the events are mapped as:
-
- 6900/6910 - Events 0-31, IRQ 13
- 6904/6924 - Events 32-63, IRQ 11
- 6908/6938 - Events 64-95, IRQ 9
-
-*/
+/*
+ * Dreamcast System ASIC Hardware Events -
+ *
+ * The Dreamcast's System ASIC (a.k.a. Holly) is responsible for receiving
+ * hardware events from system peripherals and triggering an SH7750 IRQ.
+ * Hardware events can trigger IRQs 13, 11, or 9 depending on which bits are
+ * set in the Event Mask Registers (EMRs). When a hardware event is
+ * triggered, its corresponding bit in the Event Status Registers (ESRs)
+ * is set, and that bit should be rewritten to the ESR to acknowledge that
+ * event.
+ *
+ * There are three 32-bit ESRs located at 0xa05f6900 - 0xa05f6908. Event
+ * types can be found in arch/sh/include/mach-dreamcast/mach/sysasic.h.
+ * There are three groups of EMRs that parallel the ESRs. Each EMR group
+ * corresponds to an IRQ, so 0xa05f6910 - 0xa05f6918 triggers IRQ 13,
+ * 0xa05f6920 - 0xa05f6928 triggers IRQ 11, and 0xa05f6930 - 0xa05f6938
+ * triggers IRQ 9.
+ *
+ * In the kernel, these events are mapped to virtual IRQs so that drivers can
+ * respond to them as they would a normal interrupt. In order to keep this
+ * mapping simple, the events are mapped as:
+ *
+ * 6900/6910 - Events 0-31, IRQ 13
+ * 6904/6924 - Events 32-63, IRQ 11
+ * 6908/6938 - Events 64-95, IRQ 9
+ *
+ */
#define ESR_BASE 0x005f6900 /* Base event status register */
#define EMR_BASE 0x005f6910 /* Base event mask register */
-/* Helps us determine the EMR group that this event belongs to: 0 = 0x6910,
- 1 = 0x6920, 2 = 0x6930; also determine the event offset */
+/*
+ * Helps us determine the EMR group that this event belongs to: 0 = 0x6910,
+ * 1 = 0x6920, 2 = 0x6930; also determine the event offset.
+ */
#define LEVEL(event) (((event) - HW_EVENT_IRQ_BASE) / 32)
/* Return the hardware event's bit positon within the EMR/ESR */
#define EVENT_BIT(event) (((event) - HW_EVENT_IRQ_BASE) & 31)
-/* For each of these *_irq routines, the IRQ passed in is the virtual IRQ
- (logically mapped to the corresponding bit for the hardware event). */
+/*
+ * For each of these *_irq routines, the IRQ passed in is the virtual IRQ
+ * (logically mapped to the corresponding bit for the hardware event).
+ */
/* Disable the hardware event by masking its bit in its EMR */
static inline void disable_systemasic_irq(unsigned int irq)
{
- __u32 emr = EMR_BASE + (LEVEL(irq) << 4) + (LEVEL(irq) << 2);
- __u32 mask;
+ __u32 emr = EMR_BASE + (LEVEL(irq) << 4) + (LEVEL(irq) << 2);
+ __u32 mask;
- mask = inl(emr);
- mask &= ~(1 << EVENT_BIT(irq));
- outl(mask, emr);
+ mask = inl(emr);
+ mask &= ~(1 << EVENT_BIT(irq));
+ outl(mask, emr);
}
/* Enable the hardware event by setting its bit in its EMR */
static inline void enable_systemasic_irq(unsigned int irq)
{
- __u32 emr = EMR_BASE + (LEVEL(irq) << 4) + (LEVEL(irq) << 2);
- __u32 mask;
+ __u32 emr = EMR_BASE + (LEVEL(irq) << 4) + (LEVEL(irq) << 2);
+ __u32 mask;
- mask = inl(emr);
- mask |= (1 << EVENT_BIT(irq));
- outl(mask, emr);
+ mask = inl(emr);
+ mask |= (1 << EVENT_BIT(irq));
+ outl(mask, emr);
}
/* Acknowledge a hardware event by writing its bit back to its ESR */
-static void ack_systemasic_irq(unsigned int irq)
-{
- __u32 esr = ESR_BASE + (LEVEL(irq) << 2);
- disable_systemasic_irq(irq);
- outl((1 << EVENT_BIT(irq)), esr);
-}
-
-/* After a IRQ has been ack'd and responded to, it needs to be renabled */
-static void end_systemasic_irq(unsigned int irq)
-{
- if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
- enable_systemasic_irq(irq);
-}
-
-static unsigned int startup_systemasic_irq(unsigned int irq)
-{
- enable_systemasic_irq(irq);
-
- return 0;
-}
-
-static void shutdown_systemasic_irq(unsigned int irq)
+static void mask_ack_systemasic_irq(unsigned int irq)
{
- disable_systemasic_irq(irq);
+ __u32 esr = ESR_BASE + (LEVEL(irq) << 2);
+ disable_systemasic_irq(irq);
+ outl((1 << EVENT_BIT(irq)), esr);
}
-struct hw_interrupt_type systemasic_int = {
- .typename = "System ASIC",
- .startup = startup_systemasic_irq,
- .shutdown = shutdown_systemasic_irq,
- .enable = enable_systemasic_irq,
- .disable = disable_systemasic_irq,
- .ack = ack_systemasic_irq,
- .end = end_systemasic_irq,
+struct irq_chip systemasic_int = {
+ .name = "System ASIC",
+ .mask = disable_systemasic_irq,
+ .mask_ack = mask_ack_systemasic_irq,
+ .unmask = enable_systemasic_irq,
};
/*
@@ -117,37 +101,37 @@ struct hw_interrupt_type systemasic_int = {
*/
int systemasic_irq_demux(int irq)
{
- __u32 emr, esr, status, level;
- __u32 j, bit;
-
- switch (irq) {
- case 13:
- level = 0;
- break;
- case 11:
- level = 1;
- break;
- case 9:
- level = 2;
- break;
- default:
- return irq;
- }
- emr = EMR_BASE + (level << 4) + (level << 2);
- esr = ESR_BASE + (level << 2);
-
- /* Mask the ESR to filter any spurious, unwanted interrupts */
- status = inl(esr);
- status &= inl(emr);
-
- /* Now scan and find the first set bit as the event to map */
- for (bit = 1, j = 0; j < 32; bit <<= 1, j++) {
- if (status & bit) {
- irq = HW_EVENT_IRQ_BASE + j + (level << 5);
- return irq;
- }
- }
-
- /* Not reached */
- return irq;
+ __u32 emr, esr, status, level;
+ __u32 j, bit;
+
+ switch (irq) {
+ case 13:
+ level = 0;
+ break;
+ case 11:
+ level = 1;
+ break;
+ case 9:
+ level = 2;
+ break;
+ default:
+ return irq;
+ }
+ emr = EMR_BASE + (level << 4) + (level << 2);
+ esr = ESR_BASE + (level << 2);
+
+ /* Mask the ESR to filter any spurious, unwanted interrupts */
+ status = inl(esr);
+ status &= inl(emr);
+
+ /* Now scan and find the first set bit as the event to map */
+ for (bit = 1, j = 0; j < 32; bit <<= 1, j++) {
+ if (status & bit) {
+ irq = HW_EVENT_IRQ_BASE + j + (level << 5);
+ return irq;
+ }
+ }
+
+ /* Not reached */
+ return irq;
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.