From 85d5b10f61d0930cc38e399edc1b96d772327a56 Mon Sep 17 00:00:00 2001
From: Maxim Poliakovski <maximumspatium@googlemail.com>
Date: Sun, 3 Nov 2024 15:05:45 +0100
Subject: [PATCH] sc53c94: switch to the new DMA API.

---
 devices/common/scsi/sc53c94.cpp | 69 ++++++++++++++++++++++++++++++++-
 devices/common/scsi/sc53c94.h   |  6 ++-
 devices/ioctrl/grandcentral.cpp |  4 +-
 3 files changed, 76 insertions(+), 3 deletions(-)

diff --git a/devices/common/scsi/sc53c94.cpp b/devices/common/scsi/sc53c94.cpp
index 643bf75..5c5abca 100644
--- a/devices/common/scsi/sc53c94.cpp
+++ b/devices/common/scsi/sc53c94.cpp
@@ -33,7 +33,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #include <cinttypes>
 #include <cstring>
 
-Sc53C94::Sc53C94(uint8_t chip_id, uint8_t my_id) : ScsiDevice("SC53C94", my_id)
+Sc53C94::Sc53C94(uint8_t chip_id, uint8_t my_id) : ScsiDevice("SC53C94", my_id), DmaDevice()
 {
     this->chip_id   = chip_id;
     this->my_bus_id = my_id;
@@ -751,6 +751,73 @@ void Sc53C94::dma_stop()
     }
 }
 
+int Sc53C94::xfer_from(uint8_t *buf, int len) {
+    if (len > this->xfer_count + this->data_fifo_pos)
+        LOG_F(WARNING, "%s: DMA xfer len > command xfer len", this->name.c_str());
+
+    if (this->data_fifo_pos) {
+        int fifo_bytes = std::min(this->data_fifo_pos, len);
+        std::memcpy(buf, this->data_fifo, fifo_bytes);
+        this->data_fifo_pos -= fifo_bytes;
+        this->xfer_count -= fifo_bytes;
+        len -= fifo_bytes;
+        buf += fifo_bytes;
+        if (!this->xfer_count) {
+            this->status |= STAT_TC; // signal zero transfer count
+            this->cur_state = SeqState::XFER_END;
+            this->sequencer();
+            return 0;
+        }
+    }
+
+    if (this->bus_obj->pull_data(this->target_id, buf, this->xfer_count)) {
+        this->xfer_count = 0;
+        this->status |= STAT_TC; // signal zero transfer count
+        this->cur_state = SeqState::XFER_END;
+        this->sequencer();
+        return 0;
+    }
+
+    return len;
+}
+
+int Sc53C94::xfer_to(uint8_t *buf, int len) {
+    if (!this->xfer_count)
+        return len;
+
+    // Being in the DATA_OUT phase means that we're about to move
+    // a big chunk of data. The real device uses its FIFO as buffer.
+    // For simplicity, the code below transfers the whole chunk at once.
+    // This can be broken into smaller chunks later if desired.
+    if (this->cur_bus_phase == ScsiPhase::DATA_OUT) {
+        if (this->bus_obj->push_data(this->target_id, buf, len)) {
+            this->xfer_count -= len;
+            if (!this->xfer_count) {
+                this->status |= STAT_TC; // signal zero transfer count
+                this->cur_state = SeqState::XFER_END;
+                this->sequencer();
+            }
+            len = 0;
+        } else
+            LOG_F(WARNING, "%s: xfer_to failed to transfer data", this->name.c_str());
+    }
+
+    if (this->xfer_count) {
+        // fill in the data FIFO first
+        uint32_t fifo_bytes = std::min(len, DATA_FIFO_MAX - this->data_fifo_pos);
+        std::memcpy(&this->data_fifo[this->data_fifo_pos], buf, fifo_bytes);
+        len -= fifo_bytes;
+        this->data_fifo_pos += fifo_bytes;
+        this->xfer_count -= fifo_bytes;
+        if (!this->xfer_count) {
+            this->status |= STAT_TC; // signal zero transfer count
+            this->sequencer();
+        }
+    }
+
+    return len;
+}
+
 static const PropMap Sc53C94_properties = {
     {"hdd_img", new StrProperty("")},
     {"cdr_img", new StrProperty("")},
diff --git a/devices/common/scsi/sc53c94.h b/devices/common/scsi/sc53c94.h
index 48a40ee..f525361 100644
--- a/devices/common/scsi/sc53c94.h
+++ b/devices/common/scsi/sc53c94.h
@@ -187,7 +187,7 @@ typedef struct {
 
 typedef std::function<void(const uint8_t drq_state)> DrqCb;
 
-class Sc53C94 : public ScsiDevice {
+class Sc53C94 : public ScsiDevice, public DmaDevice {
 public:
     Sc53C94(uint8_t chip_id=12, uint8_t my_id=7);
     ~Sc53C94() = default;
@@ -235,6 +235,10 @@ public:
     int  send_data(uint8_t* dst_ptr, int count);
     void process_command() {};
 
+    // DmaChannel methods
+    int xfer_from(uint8_t *buf, int len); // Must be marked override!
+    int xfer_to(uint8_t *buf, int len);   // Must be marked override!
+
 protected:
     void reset_device();
     void update_command_reg(uint8_t cmd);
diff --git a/devices/ioctrl/grandcentral.cpp b/devices/ioctrl/grandcentral.cpp
index 0ef8d40..b94518e 100644
--- a/devices/ioctrl/grandcentral.cpp
+++ b/devices/ioctrl/grandcentral.cpp
@@ -125,7 +125,9 @@ GrandCentral::GrandCentral() : PCIDevice("mac-io_grandcentral"), InterruptCtrl()
     this->curio = dynamic_cast<Sc53C94*>(gMachineObj->get_comp_by_name("Sc53C94"));
     this->curio_dma = std::unique_ptr<DMAChannel> (new DMAChannel("curio_scsi"));
     this->curio_dma->register_dma_int(this, this->register_dma_int(IntSrc::DMA_SCSI_CURIO));
-    this->curio->set_dma_channel(this->curio_dma.get());
+    this->curio_dma->connect(this->curio);
+    this->curio->connect(this->curio_dma.get());
+    //this->curio->set_dma_channel(this->curio_dma.get());
     this->curio->set_drq_callback([this](const uint8_t drq_state) {
         this->curio_dma->set_stat((drq_state & 1) << 5);
     });