1 files changed, 158 insertions, 0 deletions

diff --git a/drivers/media/video/saa7164/saa7164-buffer.c b/drivers/media/video/saa7164/saa7164-buffer.c
new file mode 100644
index 000000000000..4176544ee019
--- /dev/null
+++ b/drivers/media/video/saa7164/saa7164-buffer.c
@@ -0,0 +1,158 @@
+/*
+ *  Driver for the NXP SAA7164 PCIe bridge
+ *
+ *  Copyright (c) 2009 Steven Toth <stoth@kernellabs.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "saa7164.h"
+
+/* The PCI address space for buffer handling looks like this:
+
+ +-u32 wide-------------+
+ |                      +
+ +-u64 wide------------------------------------+
+ +                                             +
+ +----------------------+
+ | CurrentBufferPtr     + Pointer to current PCI buffer >-+
+ +----------------------+                                 |
+ | Unused               +                                 |
+ +----------------------+                                 |
+ | Pitch                + = 188 (bytes)                   |
+ +----------------------+                                 |
+ | PCI buffer size      + = pitch * number of lines (312) |
+ +----------------------+                                 |
+ |0| Buf0 Write Offset  +                                 |
+ +----------------------+                                 v
+ |1| Buf1 Write Offset  +                                 |
+ +----------------------+                                 |
+ |2| Buf2 Write Offset  +                                 |
+ +----------------------+                                 |
+ |3| Buf3 Write Offset  +                                 |
+ +----------------------+                                 |
+ ... More write offsets                                   |
+ +---------------------------------------------+          |
+ +0| set of ptrs to PCI pagetables             +          |
+ +---------------------------------------------+          |
+ +1| set of ptrs to PCI pagetables             + <--------+
+ +---------------------------------------------+
+ +2| set of ptrs to PCI pagetables             +
+ +---------------------------------------------+
+ +3| set of ptrs to PCI pagetables             + >--+
+ +---------------------------------------------+    |
+ ... More buffer pointers                           |  +----------------+
+                                                    +->| pt[0] TS data  |
+                                                    |  +----------------+
+                                                    |
+                                                    |  +----------------+
+                                                    +->| pt[1] TS data  |
+                                                    |  +----------------+
+                                                    | etc
+ */
+
+/* Allocate a new buffer structure and associated PCI space in bytes.
+ * len must be a multiple of sizeof(u64)
+ */
+struct saa7164_buffer *saa7164_buffer_alloc(struct saa7164_tsport *port,
+        u32 len)
+{
+        struct saa7164_buffer *buf = 0;
+        struct saa7164_dev *dev = port->dev;
+        int i;
+
+        if ((len == 0) || (len >= 65536) || (len % sizeof(u64))) {
+                log_warn("%s() SAA_ERR_BAD_PARAMETER\n", __func__);
+                goto ret;
+        }
+
+        buf = kzalloc(sizeof(struct saa7164_buffer), GFP_KERNEL);
+        if (buf == NULL) {
+                log_warn("%s() SAA_ERR_NO_RESOURCES\n", __func__);
+                goto ret;
+        }
+
+        buf->port = port;
+        buf->flags = SAA7164_BUFFER_FREE;
+        /* TODO: arg len is being ignored */
+        buf->pci_size = SAA7164_PT_ENTRIES * 0x1000;
+        buf->pt_size = (SAA7164_PT_ENTRIES * sizeof(u64)) + 0x1000;
+
+        /* Allocate contiguous memory */
+        buf->cpu = pci_alloc_consistent(port->dev->pci, buf->pci_size,
+                &buf->dma);
+        if (!buf->cpu)
+                goto fail1;
+
+        buf->pt_cpu = pci_alloc_consistent(port->dev->pci, buf->pt_size,
+                &buf->pt_dma);
+        if (!buf->pt_cpu)
+                goto fail2;
+
+        /* init the buffers to a known pattern, easier during debugging */
+        memset(buf->cpu, 0xff, buf->pci_size);
+        memset(buf->pt_cpu, 0xff, buf->pt_size);
+
+        dprintk(DBGLVL_BUF, "%s()   allocated buffer @ 0x%p\n", __func__, buf);
+        dprintk(DBGLVL_BUF, "  pci_cpu @ 0x%llx    dma @ 0x%llx len = 0x%x\n",
+                (u64)buf->cpu, (u64)buf->dma, buf->pci_size);
+        dprintk(DBGLVL_BUF, "   pt_cpu @ 0x%llx pt_dma @ 0x%llx len = 0x%x\n",
+                (u64)buf->pt_cpu, (u64)buf->pt_dma, buf->pt_size);
+
+        /* Format the Page Table Entries to point into the data buffer */
+        for (i = 0 ; i < SAA7164_PT_ENTRIES; i++) {
+
+                *(buf->pt_cpu + i) = buf->dma + (i * 0x1000); /* TODO */
+
+                dprintk(DBGLVL_BUF, "    pt[%02d] = 0x%llx -> 0x%llx\n",
+                        i, (u64)buf->pt_cpu, (u64)*(buf->pt_cpu));
+
+        }
+
+        goto ret;
+
+fail2:
+        pci_free_consistent(port->dev->pci, buf->pci_size, buf->cpu, buf->dma);
+fail1:
+        kfree(buf);
+
+        buf = 0;
+ret:
+        return buf;
+}
+
+int saa7164_buffer_dealloc(struct saa7164_tsport *port,
+        struct saa7164_buffer *buf)
+{
+        struct saa7164_dev *dev = port->dev;
+
+        if ((buf == 0) || (port == 0))
+                return SAA_ERR_BAD_PARAMETER;
+
+        dprintk(DBGLVL_BUF, "%s() deallocating buffer @ 0x%p\n", __func__, buf);
+
+        if (buf->flags != SAA7164_BUFFER_FREE)
+                log_warn(" freeing a non-free buffer\n");
+
+        pci_free_consistent(port->dev->pci, buf->pci_size, buf->cpu, buf->dma);
+        pci_free_consistent(port->dev->pci, buf->pt_size, buf->pt_cpu,
+                buf->pt_dma);
+
+        kfree(buf);
+
+        return SAA_OK;
+}
+