[Qemu-devel] [PATCH 4/16] S3C irq controller

[Vincent Sanders <vince@kyllikki.org>]

S3C IRQ controller

Signed-off-by: Vincent Sanders <vince@simtec.co.uk>
---
 s3c24xx_irq.c |  200 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 200 insertions(+)


diff -urN qemusvnclean/hw/s3c24xx_irq.c qemusvnpatches/hw/s3c24xx_irq.c
--- qemusvnclean/hw/s3c24xx_irq.c	1970-01-01 01:00:00.000000000 +0100
+++ qemusvnpatches/hw/s3c24xx_irq.c	2009-04-23 16:00:07.000000000 +0100
@@ -0,0 +1,200 @@
+/* hw/s3c24xx_irq.c
+ *
+ * Samsung S3C24XX IRQ controller emulation
+ *
+ * Copyright 2006, 2007, 2008 Daniel Silverstone and Vincent Sanders
+ *
+ * This file is under the terms of the GNU General Public
+ * License Version 2
+ */
+
+#include "hw.h"
+
+#include "s3c24xx.h"
+
+/* IRQ request status              RW WORD */
+#define S3C_IRQ_SRCPND 0
+/* Interrupt mode control          WR WORD */
+#define S3C_IRQ_INTMOD 1
+/* Interrupt mask control          RW WORD */
+#define S3C_IRQ_INTMSK 2
+/* IRQ priority control            WR WORD */
+#define S3C_IRQ_PRIORITY 3
+/* Interrupt request status        RW WORD */
+#define S3C_IRQ_INTPND 4
+/* Interrupt request source offset RO WORD */
+#define S3C_IRQ_OFFSET 5
+/* Sub-source pending              RW WORD */
+#define S3C_IRQ_SUBSRCPND 6
+/* Interrupt sub-mask              RW WORD */
+#define S3C_IRQ_INTSUBMSK 7
+
+
+static void
+s3c24xx_percolate_interrupt(S3CState *soc)
+{
+    /* Take the status of the srcpnd register, percolate it through, raise to
+     * CPU if necessary */
+    uint32_t ints = (soc->irq_reg[S3C_IRQ_SRCPND] & 
+                     ~soc->irq_reg[S3C_IRQ_INTMSK]);
+    int fsb = ffs(ints);
+  
+    /* TODO: Priority encoder could go here */
+    if (ints & soc->irq_reg[S3C_IRQ_INTMOD]) {
+        /* Detected a FIQ */
+        cpu_interrupt(soc->cpu_env, CPU_INTERRUPT_FIQ);
+        return;
+    } else {
+        /* No FIQ here today */
+        cpu_reset_interrupt(soc->cpu_env, CPU_INTERRUPT_FIQ);
+    }
+
+    /* No FIQ, check for a normal IRQ */
+    if (fsb) {
+        if ((soc->irq_reg[S3C_IRQ_INTPND] == 0) ||
+            (soc->irq_reg[S3C_IRQ_INTPND] > 1<<(fsb-1))) {
+            /* Current INTPND is lower priority than fsb of ints (or empty) */
+            soc->irq_reg[S3C_IRQ_INTPND] = 1<<(fsb-1);
+            soc->irq_reg[S3C_IRQ_OFFSET] = fsb-1;
+        }
+    } else {
+        /* No FSB, thus no IRQ, thus nothing to do yet */
+    }
+
+    if (soc->irq_reg[S3C_IRQ_INTPND] != 0) {
+        cpu_interrupt(soc->cpu_env, CPU_INTERRUPT_HARD);
+    } else {
+        cpu_reset_interrupt(soc->cpu_env, CPU_INTERRUPT_HARD);
+    }
+}
+
+static void
+s3c24xx_percolate_subsrc_interrupt(S3CState *soc)
+{
+    uint32_t ints;
+  
+    soc->irq_reg[S3C_IRQ_SRCPND] |= soc->irq_main_level;
+    soc->irq_reg[S3C_IRQ_SUBSRCPND] |= soc->irq_subsrc_level;
+  
+    ints = (soc->irq_reg[S3C_IRQ_SUBSRCPND] &
+            ~soc->irq_reg[S3C_IRQ_INTSUBMSK]);
+   
+    /* If UART0 has asserted, raise that */
+    if( ints & 0x7 ) {
+        soc->irq_reg[S3C_IRQ_SRCPND] |= (1<<28);
+    }
+
+    /* Ditto UART1 */
+    if( ints & 0x7<<3 ) soc->irq_reg[S3C_IRQ_SRCPND] |= (1<<23);
+
+    /* Ditto UART2 */
+    if( ints & 0x7<<6 ) soc->irq_reg[S3C_IRQ_SRCPND] |= (1<<15);
+
+    /* And percolate it through */
+    s3c24xx_percolate_interrupt(soc);
+}
+
+static void
+s3c24xx_irq_write_f(void *opaque, target_phys_addr_t addr_, uint32_t value)
+{
+    S3CState *soc = (S3CState *)opaque;
+    int addr = (addr_ >> 2) & 7;
+
+    if (addr == S3C_IRQ_SRCPND ||
+        addr == S3C_IRQ_INTPND ||
+        addr == S3C_IRQ_SUBSRCPND) {
+        soc->irq_reg[addr] &= ~value;
+    } else {
+        soc->irq_reg[addr] = value;
+    }
+
+    /* Start at the subsrc irqs and percolate from there */
+    s3c24xx_percolate_subsrc_interrupt(soc);
+}
+
+static uint32_t
+s3c24xx_irq_read_f(void *opaque, target_phys_addr_t addr_)
+{
+    S3CState *soc = (S3CState *)opaque;
+    int addr = (addr_ >> 2) & 0x7;
+
+    return soc->irq_reg[addr];
+}
+
+
+static CPUReadMemoryFunc *s3c24xx_irq_read[] = {
+    &s3c24xx_irq_read_f,
+    &s3c24xx_irq_read_f,
+    &s3c24xx_irq_read_f,
+};
+
+static CPUWriteMemoryFunc *s3c24xx_irq_write[] = {
+    &s3c24xx_irq_write_f,
+    &s3c24xx_irq_write_f,
+    &s3c24xx_irq_write_f,
+};
+
+static void
+s3c24xx_irq_set_interrupt_level(S3CState *soc, int irq_num, int level, int set_level)
+{
+    if (level) {
+        if (set_level) soc->irq_main_level |= 1<<irq_num;
+        soc->irq_reg[S3C_IRQ_SRCPND] |= 1<<irq_num;
+    } else {
+        soc->irq_main_level &= ~(1<<irq_num);
+        soc->irq_reg[S3C_IRQ_SRCPND] &= ~(1<<irq_num);
+    }
+    s3c24xx_percolate_subsrc_interrupt(soc);
+}
+
+static void
+s3c24xx_irq_set_subsrc_interrupt_level(S3CState *soc, int irq_num, int level, int set_level)
+{
+
+    if (level) {
+        if (set_level) soc->irq_subsrc_level |= 1<<irq_num;
+        soc->irq_reg[S3C_IRQ_SUBSRCPND] |= 1<<irq_num;
+    } else {
+        soc->irq_subsrc_level &= ~(1<<irq_num);
+        soc->irq_reg[S3C_IRQ_SUBSRCPND] &= ~(1<<irq_num);
+    }
+    s3c24xx_percolate_subsrc_interrupt(soc);
+}
+
+static void
+s3c24xx_irq_handler(void *opaque, int _n, int level)
+{
+    S3CState *soc = (S3CState *)opaque;
+    int irq_num = _n % 32;
+    int is_subsrc = (_n & 32)?1:0;
+    int is_level = (_n & 64)?1:0;
+
+    if (is_subsrc == 0)
+        s3c24xx_irq_set_interrupt_level(soc, irq_num, level, is_level);
+    else
+        s3c24xx_irq_set_subsrc_interrupt_level(soc, irq_num, level, is_level);
+}
+
+qemu_irq *
+s3c24xx_irq_init(S3CState *soc, target_phys_addr_t base_addr)
+{
+    /* Samsung S3C2410X IRQ registration. */
+    int tag = cpu_register_io_memory(0, s3c24xx_irq_read, s3c24xx_irq_write, soc);
+    cpu_register_physical_memory(base_addr, 8 * 4, tag);
+
+    /* Set up registers to power on values */
+    soc->irq_reg[S3C_IRQ_SRCPND] = 0x00;
+    soc->irq_reg[S3C_IRQ_INTMOD] = 0x00;
+    soc->irq_reg[S3C_IRQ_INTMSK] = 0xFFFFFFFF;
+    soc->irq_reg[S3C_IRQ_PRIORITY] = 0x7F; 
+    soc->irq_reg[S3C_IRQ_INTPND] = 0x00;
+    soc->irq_reg[S3C_IRQ_OFFSET] = 0x00;
+    soc->irq_reg[S3C_IRQ_SUBSRCPND] = 0x00;
+    soc->irq_reg[S3C_IRQ_INTSUBMSK] = 0x7FF;
+
+    /* Allocate the interrupts and return them. All 64 potential ones.
+     * We return them doubled up because the latter half are level where
+     * the former half are edge.
+     */
+    return qemu_allocate_irqs(s3c24xx_irq_handler, soc, 128);
+}

-- 
Regards Vincent
http://www.kyllikki.org/