lm32: add Milkymist AC97 support

This patch adds support for the Milkymist AC97 compatible sound output and
input core.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>

1 files changed, 335 insertions, 0 deletions

diff --git a/hw/milkymist-ac97.c b/hw/milkymist-ac97.c
new file mode 100644
index 0000000000..6c9e318aa2
--- /dev/null
+++ b/hw/milkymist-ac97.c
@@ -0,0 +1,335 @@
+/*
+ *  QEMU model of the Milkymist System Controller.
+ *
+ *  Copyright (c) 2010 Michael Walle <michael@walle.cc>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * Specification available at:
+ *   http://www.milkymist.org/socdoc/ac97.pdf
+ */
+
+#include "hw.h"
+#include "sysbus.h"
+#include "trace.h"
+#include "audio/audio.h"
+#include "qemu-error.h"
+
+enum {
+    R_AC97_CTRL = 0,
+    R_AC97_ADDR,
+    R_AC97_DATAOUT,
+    R_AC97_DATAIN,
+    R_D_CTRL,
+    R_D_ADDR,
+    R_D_REMAINING,
+    R_RESERVED,
+    R_U_CTRL,
+    R_U_ADDR,
+    R_U_REMAINING,
+    R_MAX
+};
+
+enum {
+    AC97_CTRL_RQEN  = (1<<0),
+    AC97_CTRL_WRITE = (1<<1),
+};
+
+enum {
+    CTRL_EN = (1<<0),
+};
+
+struct MilkymistAC97State {
+    SysBusDevice busdev;
+
+    QEMUSoundCard card;
+    SWVoiceIn *voice_in;
+    SWVoiceOut *voice_out;
+
+    uint32_t regs[R_MAX];
+
+    qemu_irq crrequest_irq;
+    qemu_irq crreply_irq;
+    qemu_irq dmar_irq;
+    qemu_irq dmaw_irq;
+};
+typedef struct MilkymistAC97State MilkymistAC97State;
+
+static void update_voices(MilkymistAC97State *s)
+{
+    if (s->regs[R_D_CTRL] & CTRL_EN) {
+        AUD_set_active_out(s->voice_out, 1);
+    } else {
+        AUD_set_active_out(s->voice_out, 0);
+    }
+
+    if (s->regs[R_U_CTRL] & CTRL_EN) {
+        AUD_set_active_in(s->voice_in, 1);
+    } else {
+        AUD_set_active_in(s->voice_in, 0);
+    }
+}
+
+static uint32_t ac97_read(void *opaque, target_phys_addr_t addr)
+{
+    MilkymistAC97State *s = opaque;
+    uint32_t r = 0;
+
+    addr >>= 2;
+    switch (addr) {
+    case R_AC97_CTRL:
+    case R_AC97_ADDR:
+    case R_AC97_DATAOUT:
+    case R_AC97_DATAIN:
+    case R_D_CTRL:
+    case R_D_ADDR:
+    case R_D_REMAINING:
+    case R_U_CTRL:
+    case R_U_ADDR:
+    case R_U_REMAINING:
+        r = s->regs[addr];
+        break;
+
+    default:
+        error_report("milkymist_ac97: read access to unkown register 0x"
+                TARGET_FMT_plx, addr << 2);
+        break;
+    }
+
+    trace_milkymist_ac97_memory_read(addr << 2, r);
+
+    return r;
+}
+
+static void ac97_write(void *opaque, target_phys_addr_t addr, uint32_t value)
+{
+    MilkymistAC97State *s = opaque;
+
+    trace_milkymist_ac97_memory_write(addr, value);
+
+    addr >>= 2;
+    switch (addr) {
+    case R_AC97_CTRL:
+        /* always raise an IRQ according to the direction */
+        if (value & AC97_CTRL_RQEN) {
+            if (value & AC97_CTRL_WRITE) {
+                trace_milkymist_ac97_pulse_irq_crrequest();
+                qemu_irq_pulse(s->crrequest_irq);
+            } else {
+                trace_milkymist_ac97_pulse_irq_crreply();
+                qemu_irq_pulse(s->crreply_irq);
+            }
+        }
+
+        /* RQEN is self clearing */
+        s->regs[addr] = value & ~AC97_CTRL_RQEN;
+        break;
+    case R_D_CTRL:
+    case R_U_CTRL:
+        s->regs[addr] = value;
+        update_voices(s);
+        break;
+    case R_AC97_ADDR:
+    case R_AC97_DATAOUT:
+    case R_AC97_DATAIN:
+    case R_D_ADDR:
+    case R_D_REMAINING:
+    case R_U_ADDR:
+    case R_U_REMAINING:
+        s->regs[addr] = value;
+        break;
+
+    default:
+        error_report("milkymist_ac97: write access to unkown register 0x"
+                TARGET_FMT_plx, addr);
+        break;
+    }
+
+}
+
+static CPUReadMemoryFunc * const ac97_read_fn[] = {
+    NULL,
+    NULL,
+    &ac97_read,
+};
+
+static CPUWriteMemoryFunc * const ac97_write_fn[] = {
+    NULL,
+    NULL,
+    &ac97_write,
+};
+
+static void ac97_in_cb(void *opaque, int avail_b)
+{
+    MilkymistAC97State *s = opaque;
+    uint8_t buf[4096];
+    uint32_t remaining = s->regs[R_U_REMAINING];
+    int temp = audio_MIN(remaining, avail_b);
+    uint32_t addr = s->regs[R_U_ADDR];
+    int transferred = 0;
+
+    trace_milkymist_ac97_in_cb(avail_b, remaining);
+
+    /* prevent from raising an IRQ */
+    if (temp == 0) {
+        return;
+    }
+
+    while (temp) {
+        int acquired, to_copy;
+
+        to_copy = audio_MIN(temp, sizeof(buf));
+        acquired = AUD_read(s->voice_in, buf, to_copy);
+        if (!acquired) {
+            break;
+        }
+
+        cpu_physical_memory_write(addr, buf, acquired);
+
+        temp -= acquired;
+        addr += acquired;
+        transferred += acquired;
+    }
+
+    trace_milkymist_ac97_in_cb_transferred(transferred);
+
+    s->regs[R_U_ADDR] = addr;
+    s->regs[R_U_REMAINING] -= transferred;
+
+    if ((s->regs[R_U_CTRL] & CTRL_EN) && (s->regs[R_U_REMAINING] == 0)) {
+        trace_milkymist_ac97_pulse_irq_dmaw();
+        qemu_irq_pulse(s->dmaw_irq);
+    }
+}
+
+static void ac97_out_cb(void *opaque, int free_b)
+{
+    MilkymistAC97State *s = opaque;
+    uint8_t buf[4096];
+    uint32_t remaining = s->regs[R_D_REMAINING];
+    int temp = audio_MIN(remaining, free_b);
+    uint32_t addr = s->regs[R_D_ADDR];
+    int transferred = 0;
+
+    trace_milkymist_ac97_out_cb(free_b, remaining);
+
+    /* prevent from raising an IRQ */
+    if (temp == 0) {
+        return;
+    }
+
+    while (temp) {
+        int copied, to_copy;
+
+        to_copy = audio_MIN(temp, sizeof(buf));
+        cpu_physical_memory_read(addr, buf, to_copy);
+        copied = AUD_write(s->voice_out, buf, to_copy);
+        if (!copied) {
+            break;
+        }
+        temp -= copied;
+        addr += copied;
+        transferred += copied;
+    }
+
+    trace_milkymist_ac97_out_cb_transferred(transferred);
+
+    s->regs[R_D_ADDR] = addr;
+    s->regs[R_D_REMAINING] -= transferred;
+
+    if ((s->regs[R_D_CTRL] & CTRL_EN) && (s->regs[R_D_REMAINING] == 0)) {
+        trace_milkymist_ac97_pulse_irq_dmar();
+        qemu_irq_pulse(s->dmar_irq);
+    }
+}
+
+static void milkymist_ac97_reset(DeviceState *d)
+{
+    MilkymistAC97State *s = container_of(d, MilkymistAC97State, busdev.qdev);
+    int i;
+
+    for (i = 0; i < R_MAX; i++) {
+        s->regs[i] = 0;
+    }
+
+    AUD_set_active_in(s->voice_in, 0);
+    AUD_set_active_out(s->voice_out, 0);
+}
+
+static int ac97_post_load(void *opaque, int version_id)
+{
+    MilkymistAC97State *s = opaque;
+
+    update_voices(s);
+
+    return 0;
+}
+
+static int milkymist_ac97_init(SysBusDevice *dev)
+{
+    MilkymistAC97State *s = FROM_SYSBUS(typeof(*s), dev);
+    int ac97_regs;
+
+    struct audsettings as;
+    sysbus_init_irq(dev, &s->crrequest_irq);
+    sysbus_init_irq(dev, &s->crreply_irq);
+    sysbus_init_irq(dev, &s->dmar_irq);
+    sysbus_init_irq(dev, &s->dmaw_irq);
+
+    AUD_register_card("Milkymist AC'97", &s->card);
+
+    as.freq = 48000;
+    as.nchannels = 2;
+    as.fmt = AUD_FMT_S16;
+    as.endianness = 1;
+
+    s->voice_in = AUD_open_in(&s->card, s->voice_in,
+            "mm_ac97.in", s, ac97_in_cb, &as);
+    s->voice_out = AUD_open_out(&s->card, s->voice_out,
+            "mm_ac97.out", s, ac97_out_cb, &as);
+
+    ac97_regs = cpu_register_io_memory(ac97_read_fn, ac97_write_fn, s,
+            DEVICE_NATIVE_ENDIAN);
+    sysbus_init_mmio(dev, R_MAX * 4, ac97_regs);
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_milkymist_ac97 = {
+    .name = "milkymist-ac97",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .post_load = ac97_post_load,
+    .fields      = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(regs, MilkymistAC97State, R_MAX),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static SysBusDeviceInfo milkymist_ac97_info = {
+    .init = milkymist_ac97_init,
+    .qdev.name  = "milkymist-ac97",
+    .qdev.size  = sizeof(MilkymistAC97State),
+    .qdev.vmsd  = &vmstate_milkymist_ac97,
+    .qdev.reset = milkymist_ac97_reset,
+};
+
+static void milkymist_ac97_register(void)
+{
+    sysbus_register_withprop(&milkymist_ac97_info);
+}
+
+device_init(milkymist_ac97_register)