--- /dev/null
+/*
+ * tw68_risc.c
+ * Part of the device driver for Techwell 68xx based cards
+ *
+ * Much of this code is derived from the cx88 and sa7134 drivers, which
+ * were in turn derived from the bt87x driver. The original work was by
+ * Gerd Knorr; more recently the code was enhanced by Mauro Carvalho Chehab,
+ * Hans Verkuil, Andy Walls and many others. Their work is gratefully
+ * acknowledged. Full credit goes to them - any problems within this code
+ * are mine.
+ *
+ * Copyright (C) 2009 William M. Brack
+ *
+ * Refactored and updated to the latest v4l core frameworks:
+ *
+ * Copyright (C) 2014 Hans Verkuil <hverkuil@xs4all.nl>
+ *
+ * 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.
+ */
+
+#include "tw68.h"
+
+/**
+ * @rp pointer to current risc program position
+ * @sglist pointer to "scatter-gather list" of buffer pointers
+ * @offset offset to target memory buffer
+ * @sync_line 0 -> no sync, 1 -> odd sync, 2 -> even sync
+ * @bpl number of bytes per scan line
+ * @padding number of bytes of padding to add
+ * @lines number of lines in field
+ * @jump insert a jump at the start
+ */
+static __le32 *tw68_risc_field(__le32 *rp, struct scatterlist *sglist,
+ unsigned int offset, u32 sync_line,
+ unsigned int bpl, unsigned int padding,
+ unsigned int lines, bool jump)
+{
+ struct scatterlist *sg;
+ unsigned int line, todo, done;
+
+ if (jump) {
+ *(rp++) = cpu_to_le32(RISC_JUMP);
+ *(rp++) = 0;
+ }
+
+ /* sync instruction */
+ if (sync_line == 1)
+ *(rp++) = cpu_to_le32(RISC_SYNCO);
+ else
+ *(rp++) = cpu_to_le32(RISC_SYNCE);
+ *(rp++) = 0;
+
+ /* scan lines */
+ sg = sglist;
+ for (line = 0; line < lines; line++) {
+ /* calculate next starting position */
+ while (offset && offset >= sg_dma_len(sg)) {
+ offset -= sg_dma_len(sg);
+ sg = sg_next(sg);
+ }
+ if (bpl <= sg_dma_len(sg) - offset) {
+ /* fits into current chunk */
+ *(rp++) = cpu_to_le32(RISC_LINESTART |
+ /* (offset<<12) |*/ bpl);
+ *(rp++) = cpu_to_le32(sg_dma_address(sg) + offset);
+ offset += bpl;
+ } else {
+ /*
+ * scanline needs to be split. Put the start in
+ * whatever memory remains using RISC_LINESTART,
+ * then the remainder into following addresses
+ * given by the scatter-gather list.
+ */
+ todo = bpl; /* one full line to be done */
+ /* first fragment */
+ done = (sg_dma_len(sg) - offset);
+ *(rp++) = cpu_to_le32(RISC_LINESTART |
+ (7 << 24) |
+ done);
+ *(rp++) = cpu_to_le32(sg_dma_address(sg) + offset);
+ todo -= done;
+ sg = sg_next(sg);
+ /* succeeding fragments have no offset */
+ while (todo > sg_dma_len(sg)) {
+ *(rp++) = cpu_to_le32(RISC_INLINE |
+ (done << 12) |
+ sg_dma_len(sg));
+ *(rp++) = cpu_to_le32(sg_dma_address(sg));
+ todo -= sg_dma_len(sg);
+ sg = sg_next(sg);
+ done += sg_dma_len(sg);
+ }
+ if (todo) {
+ /* final chunk - offset 0, count 'todo' */
+ *(rp++) = cpu_to_le32(RISC_INLINE |
+ (done << 12) |
+ todo);
+ *(rp++) = cpu_to_le32(sg_dma_address(sg));
+ }
+ offset = todo;
+ }
+ offset += padding;
+ }
+
+ return rp;
+}
+
+/**
+ * tw68_risc_buffer
+ *
+ * This routine is called by tw68-video. It allocates
+ * memory for the dma controller "program" and then fills in that
+ * memory with the appropriate "instructions".
+ *
+ * @pci_dev structure with info about the pci
+ * slot which our device is in.
+ * @risc structure with info about the memory
+ * used for our controller program.
+ * @sglist scatter-gather list entry
+ * @top_offset offset within the risc program area for the
+ * first odd frame line
+ * @bottom_offset offset within the risc program area for the
+ * first even frame line
+ * @bpl number of data bytes per scan line
+ * @padding number of extra bytes to add at end of line
+ * @lines number of scan lines
+ */
+int tw68_risc_buffer(struct pci_dev *pci,
+ struct tw68_buf *buf,
+ struct scatterlist *sglist,
+ unsigned int top_offset,
+ unsigned int bottom_offset,
+ unsigned int bpl,
+ unsigned int padding,
+ unsigned int lines)
+{
+ u32 instructions, fields;
+ __le32 *rp;
+
+ fields = 0;
+ if (UNSET != top_offset)
+ fields++;
+ if (UNSET != bottom_offset)
+ fields++;
+ /*
+ * estimate risc mem: worst case is one write per page border +
+ * one write per scan line + syncs + 2 jumps (all 2 dwords).
+ * Padding can cause next bpl to start close to a page border.
+ * First DMA region may be smaller than PAGE_SIZE
+ */
+ instructions = fields * (1 + (((bpl + padding) * lines) /
+ PAGE_SIZE) + lines) + 4;
+ buf->size = instructions * 8;
+ buf->cpu = pci_alloc_consistent(pci, buf->size, &buf->dma);
+ if (buf->cpu == NULL)
+ return -ENOMEM;
+
+ /* write risc instructions */
+ rp = buf->cpu;
+ if (UNSET != top_offset) /* generates SYNCO */
+ rp = tw68_risc_field(rp, sglist, top_offset, 1,
+ bpl, padding, lines, true);
+ if (UNSET != bottom_offset) /* generates SYNCE */
+ rp = tw68_risc_field(rp, sglist, bottom_offset, 2,
+ bpl, padding, lines, top_offset == UNSET);
+
+ /* save pointer to jmp instruction address */
+ buf->jmp = rp;
+ buf->cpu[1] = cpu_to_le32(buf->dma + 8);
+ /* assure risc buffer hasn't overflowed */
+ BUG_ON((buf->jmp - buf->cpu + 2) * sizeof(buf->cpu[0]) > buf->size);
+ return 0;
+}
+
+#if 0
+/* ------------------------------------------------------------------ */
+/* debug helper code */
+
+static void tw68_risc_decode(u32 risc, u32 addr)
+{
+#define RISC_OP(reg) (((reg) >> 28) & 7)
+ static struct instr_details {
+ char *name;
+ u8 has_data_type;
+ u8 has_byte_info;
+ u8 has_addr;
+ } instr[8] = {
+ [RISC_OP(RISC_SYNCO)] = {"syncOdd", 0, 0, 0},
+ [RISC_OP(RISC_SYNCE)] = {"syncEven", 0, 0, 0},
+ [RISC_OP(RISC_JUMP)] = {"jump", 0, 0, 1},
+ [RISC_OP(RISC_LINESTART)] = {"lineStart", 1, 1, 1},
+ [RISC_OP(RISC_INLINE)] = {"inline", 1, 1, 1},
+ };
+ u32 p;
+
+ p = RISC_OP(risc);
+ if (!(risc & 0x80000000) || !instr[p].name) {
+ pr_debug("0x%08x [ INVALID ]\n", risc);
+ return;
+ }
+ pr_debug("0x%08x %-9s IRQ=%d",
+ risc, instr[p].name, (risc >> 27) & 1);
+ if (instr[p].has_data_type)
+ pr_debug(" Type=%d", (risc >> 24) & 7);
+ if (instr[p].has_byte_info)
+ pr_debug(" Start=0x%03x Count=%03u",
+ (risc >> 12) & 0xfff, risc & 0xfff);
+ if (instr[p].has_addr)
+ pr_debug(" StartAddr=0x%08x", addr);
+ pr_debug("\n");
+}
+
+void tw68_risc_program_dump(struct tw68_core *core, struct tw68_buf *buf)
+{
+ const __le32 *addr;
+
+ pr_debug("%s: risc_program_dump: risc=%p, buf->cpu=0x%p, buf->jmp=0x%p\n",
+ core->name, buf, buf->cpu, buf->jmp);
+ for (addr = buf->cpu; addr <= buf->jmp; addr += 2)
+ tw68_risc_decode(*addr, *(addr+1));
+}
+#endif
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