[Qemu-devel] [4300] ETRAX serial port:

[Edgar E. Iglesias]

Revision: 4300
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=4300
Author:   edgar_igl
Date:     2008-05-02 22:21:55 +0000 (Fri, 02 May 2008)

Log Message:
-----------
ETRAX serial port:
* Simulate basic interrupt driven serial io.
* Connect to qemu char dev.

Modified Paths:
--------------
    trunk/hw/etraxfs_ser.c

Modified: trunk/hw/etraxfs_ser.c
===================================================================
--- trunk/hw/etraxfs_ser.c      2008-05-02 22:16:17 UTC (rev 4299)
+++ trunk/hw/etraxfs_ser.c      2008-05-02 22:21:55 UTC (rev 4300)
@@ -25,21 +25,68 @@
 #include <stdio.h>
 #include <ctype.h>
 #include "hw.h"
+#include "qemu-char.h"
 
 #define D(x)
 
-#define RW_TR_DMA_EN 0x04
-#define RW_DOUT 0x1c
-#define RW_STAT_DIN 0x20
-#define R_STAT_DIN 0x24
+#define RW_TR_CTRL     0x00
+#define RW_TR_DMA_EN   0x04
+#define RW_REC_CTRL    0x08
+#define RW_DOUT        0x1c
+#define RS_STAT_DIN    0x20
+#define R_STAT_DIN     0x24
+#define RW_INTR_MASK   0x2c
+#define RW_ACK_INTR    0x30
+#define R_INTR         0x34
+#define R_MASKED_INTR  0x38
 
-static uint32_t ser_readb (void *opaque, target_phys_addr_t addr)
+#define STAT_DAV     16
+#define STAT_TR_IDLE 22
+#define STAT_TR_RDY  24
+
+struct etrax_serial_t
 {
-       D(CPUState *env = opaque);
-       D(printf ("%s %x pc=%x\n", __func__, addr, env->pc));
-       return 0;
+       CPUState *env;
+       CharDriverState *chr;
+       qemu_irq *irq;
+
+       target_phys_addr_t base;
+
+       int pending_tx;
+
+       /* Control registers.  */
+       uint32_t rw_tr_ctrl;
+       uint32_t rw_tr_dma_en;
+       uint32_t rw_rec_ctrl;
+       uint32_t rs_stat_din;
+       uint32_t r_stat_din;
+       uint32_t rw_intr_mask;
+       uint32_t rw_ack_intr;
+       uint32_t r_intr;
+       uint32_t r_masked_intr;
+};
+
+static void ser_update_irq(struct etrax_serial_t *s)
+{
+       uint32_t o_irq = s->r_masked_intr;
+
+       s->r_intr &= ~(s->rw_ack_intr);
+       s->r_masked_intr = s->r_intr & s->rw_intr_mask;
+
+       if (o_irq != s->r_masked_intr) {
+               D(printf("irq_mask=%x r_intr=%x rmi=%x airq=%x \n", 
+                        s->rw_intr_mask, s->r_intr, 
+                        s->r_masked_intr, s->rw_ack_intr));
+               if (s->r_masked_intr)
+                       qemu_irq_raise(s->irq[0]);
+               else
+                       qemu_irq_lower(s->irq[0]);
+       }
+       s->rw_ack_intr = 0;
 }
-static uint32_t ser_readw (void *opaque, target_phys_addr_t addr)
+
+
+static uint32_t ser_readb (void *opaque, target_phys_addr_t addr)
 {
        D(CPUState *env = opaque);
        D(printf ("%s %x pc=%x\n", __func__, addr, env->pc));
@@ -48,17 +95,41 @@
 
 static uint32_t ser_readl (void *opaque, target_phys_addr_t addr)
 {
-       D(CPUState *env = opaque);
+       struct etrax_serial_t *s = opaque;
+       D(CPUState *env = s->env);
        uint32_t r = 0;
 
        switch (addr & 0xfff)
        {
+               case RW_TR_CTRL:
+                       r = s->rw_tr_ctrl;
+                       break;
                case RW_TR_DMA_EN:
+                       r = s->rw_tr_dma_en;
                        break;
+               case RS_STAT_DIN:
+                       r = s->rs_stat_din;
+                       /* clear dav.  */
+                       s->rs_stat_din &= ~(1 << STAT_DAV);
+                       break;
                case R_STAT_DIN:
-                       r |= 1 << 24; /* set tr_rdy.  */
-                       r |= 1 << 22; /* set tr_idle.  */
+                       r = s->rs_stat_din;
                        break;
+               case RW_ACK_INTR:
+                       D(printf("load rw_ack_intr=%x\n", s->rw_ack_intr));
+                       r = s->rw_ack_intr;
+                       break;
+               case RW_INTR_MASK:
+                       r = s->rw_intr_mask;
+                       break;
+               case R_INTR:
+                       D(printf("load r_intr=%x\n", s->r_intr));
+                       r = s->r_intr;
+                       break;
+               case R_MASKED_INTR:
+                       D(printf("load r_maked_intr=%x\n", s->r_masked_intr));
+                       r = s->r_masked_intr;
+                       break;
 
                default:
                        D(printf ("%s %x p=%x\n", __func__, addr, env->pc));
@@ -70,53 +141,117 @@
 static void
 ser_writeb (void *opaque, target_phys_addr_t addr, uint32_t value)
 {
-       D(CPUState *env = opaque);
+       D(struct etrax_serial_t *s = opaque);
+       D(CPUState *env = s->env);
        D(printf ("%s %x %x pc=%x\n", __func__, addr, value, env->pc));
 }
 static void
-ser_writew (void *opaque, target_phys_addr_t addr, uint32_t value)
-{
-       D(CPUState *env = opaque);
-       D(printf ("%s %x %x pc=%x\n", __func__, addr, value, env->pc));
-}
-static void
 ser_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
 {
-       D(CPUState *env = opaque);
+       struct etrax_serial_t *s = opaque;
+       unsigned char ch = value;
+       D(CPUState *env = s->env);
 
        switch (addr & 0xfff)
        {
+               case RW_TR_CTRL:
+                       D(printf("rw_tr_ctrl=%x\n", value));
+                       s->rw_tr_ctrl = value;
+                       break;
                case RW_TR_DMA_EN:
+                       D(printf("rw_tr_dma_en=%x\n", value));
+                       s->rw_tr_dma_en = value;
                        break;
                case RW_DOUT:
-                       if (isprint(value) || isspace(value))
-                               putchar(value);
-                       else
-                               putchar('.');
-                       fflush(stdout);
+                       qemu_chr_write(s->chr, &ch, 1);
+                       s->r_intr |= 1;
+                       s->pending_tx = 1;
                        break;
+               case RW_ACK_INTR:
+                       D(printf("rw_ack_intr=%x\n", value));
+                       s->rw_ack_intr = value;
+                       if (s->pending_tx && (s->rw_ack_intr & 1)) {
+                               s->r_intr |= 1;
+                               s->pending_tx = 0;
+                               s->rw_ack_intr &= ~1;
+                       }
+                       break;
+               case RW_INTR_MASK:
+                       D(printf("r_intr_mask=%x\n", value));
+                       s->rw_intr_mask = value;
+                       break;
                default:
                        D(printf ("%s %x %x pc=%x\n",
                                  __func__, addr, value, env->pc));
                        break;
        }
+       ser_update_irq(s);
 }
 
 static CPUReadMemoryFunc *ser_read[] = {
        &ser_readb,
-       &ser_readw,
+       &ser_readb,
        &ser_readl,
 };
 
 static CPUWriteMemoryFunc *ser_write[] = {
        &ser_writeb,
-       &ser_writew,
+       &ser_writeb,
        &ser_writel,
 };
 
-void etraxfs_ser_init(CPUState *env, qemu_irq *irqs, target_phys_addr_t base)
+static void serial_receive(void *opaque, const uint8_t *buf, int size)
 {
+       struct etrax_serial_t *s = opaque;
+
+       s->r_intr |= 8;
+       s->rs_stat_din &= ~0xff;
+       s->rs_stat_din |= (buf[0] & 0xff);
+       s->rs_stat_din |= (1 << STAT_DAV); /* dav.  */
+       ser_update_irq(s);
+}
+
+static int serial_can_receive(void *opaque)
+{
+       struct etrax_serial_t *s = opaque;
+       int r;
+
+       /* Is the receiver enabled?  */
+       r = s->rw_rec_ctrl & 1;
+
+       /* Pending rx data?  */
+       r |= !(s->r_intr & 8);
+       return r;
+}
+
+static void serial_event(void *opaque, int event)
+{
+
+}
+
+void etraxfs_ser_init(CPUState *env, qemu_irq *irq, CharDriverState *chr,
+                     target_phys_addr_t base)
+{
+       struct etrax_serial_t *s;
        int ser_regs;
-       ser_regs = cpu_register_io_memory(0, ser_read, ser_write, env);
+
+       s = qemu_mallocz(sizeof *s);
+       if (!s)
+               return;
+
+       s->env = env;
+       s->irq = irq;
+       s->base = base;
+
+       s->chr = chr;
+
+       /* transmitter begins ready and idle.  */
+       s->rs_stat_din |= (1 << STAT_TR_RDY);
+       s->rs_stat_din |= (1 << STAT_TR_IDLE);
+
+       qemu_chr_add_handlers(chr, serial_can_receive, serial_receive,
+                             serial_event, s);
+
+       ser_regs = cpu_register_io_memory(0, ser_read, ser_write, s);
        cpu_register_physical_memory (base, 0x3c, ser_regs);
 }