drivers/media/pci/tw68/tw68-risc.c

   1 /*
   2  *  tw68_risc.c
   3  *  Part of the device driver for Techwell 68xx based cards
   4  *
   5  *  Much of this code is derived from the cx88 and sa7134 drivers, which
   6  *  were in turn derived from the bt87x driver.  The original work was by
   7  *  Gerd Knorr; more recently the code was enhanced by Mauro Carvalho Chehab,
   8  *  Hans Verkuil, Andy Walls and many others.  Their work is gratefully
   9  *  acknowledged.  Full credit goes to them - any problems within this code
  10  *  are mine.
  11  *
  12  *  Copyright (C) 2009  William M. Brack
  13  *
  14  *  Refactored and updated to the latest v4l core frameworks:
  15  *
  16  *  Copyright (C) 2014 Hans Verkuil <hverkuil@xs4all.nl>
  17  *
  18  *  This program is free software; you can redistribute it and/or modify
  19  *  it under the terms of the GNU General Public License as published by
  20  *  the Free Software Foundation; either version 2 of the License, or
  21  *  (at your option) any later version.
  22  *
  23  *  This program is distributed in the hope that it will be useful,
  24  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  *  GNU General Public License for more details.
  27  */
  28
  29 #include "tw68.h"
  30
  31 /**
  32  *  @rp         pointer to current risc program position
  33  *  @sglist     pointer to "scatter-gather list" of buffer pointers
  34  *  @offset     offset to target memory buffer
  35  *  @sync_line  0 -> no sync, 1 -> odd sync, 2 -> even sync
  36  *  @bpl        number of bytes per scan line
  37  *  @padding    number of bytes of padding to add
  38  *  @lines      number of lines in field
  39  *  @jump       insert a jump at the start
  40  */
  41 static __le32 *tw68_risc_field(__le32 *rp, struct scatterlist *sglist,
  42                             unsigned int offset, u32 sync_line,
  43                             unsigned int bpl, unsigned int padding,
  44                             unsigned int lines, bool jump)
  45 {
  46         struct scatterlist *sg;
  47         unsigned int line, todo, done;
  48
  49         if (jump) {
  50                 *(rp++) = cpu_to_le32(RISC_JUMP);
  51                 *(rp++) = 0;
  52         }
  53
  54         /* sync instruction */
  55         if (sync_line == 1)
  56                 *(rp++) = cpu_to_le32(RISC_SYNCO);
  57         else
  58                 *(rp++) = cpu_to_le32(RISC_SYNCE);
  59         *(rp++) = 0;
  60
  61         /* scan lines */
  62         sg = sglist;
  63         for (line = 0; line < lines; line++) {
  64                 /* calculate next starting position */
  65                 while (offset && offset >= sg_dma_len(sg)) {
  66                         offset -= sg_dma_len(sg);
  67                         sg = sg_next(sg);
  68                 }
  69                 if (bpl <= sg_dma_len(sg) - offset) {
  70                         /* fits into current chunk */
  71                         *(rp++) = cpu_to_le32(RISC_LINESTART |
  72                                               /* (offset<<12) |*/  bpl);
  73                         *(rp++) = cpu_to_le32(sg_dma_address(sg) + offset);
  74                         offset += bpl;
  75                 } else {
  76                         /*
  77                          * scanline needs to be split.  Put the start in
  78                          * whatever memory remains using RISC_LINESTART,
  79                          * then the remainder into following addresses
  80                          * given by the scatter-gather list.
  81                          */
  82                         todo = bpl;     /* one full line to be done */
  83                         /* first fragment */
  84                         done = (sg_dma_len(sg) - offset);
  85                         *(rp++) = cpu_to_le32(RISC_LINESTART |
  86                                                 (7 << 24) |
  87                                                 done);
  88                         *(rp++) = cpu_to_le32(sg_dma_address(sg) + offset);
  89                         todo -= done;
  90                         sg = sg_next(sg);
  91                         /* succeeding fragments have no offset */
  92                         while (todo > sg_dma_len(sg)) {
  93                                 *(rp++) = cpu_to_le32(RISC_INLINE |
  94                                                 (done << 12) |
  95                                                 sg_dma_len(sg));
  96                                 *(rp++) = cpu_to_le32(sg_dma_address(sg));
  97                                 todo -= sg_dma_len(sg);
  98                                 sg = sg_next(sg);
  99                                 done += sg_dma_len(sg);
 100                         }
 101                         if (todo) {
 102                                 /* final chunk - offset 0, count 'todo' */
 103                                 *(rp++) = cpu_to_le32(RISC_INLINE |
 104                                                         (done << 12) |
 105                                                         todo);
 106                                 *(rp++) = cpu_to_le32(sg_dma_address(sg));
 107                         }
 108                         offset = todo;
 109                 }
 110                 offset += padding;
 111         }
 112
 113         return rp;
 114 }
 115
 116 /**
 117  * tw68_risc_buffer
 118  *
 119  *      This routine is called by tw68-video.  It allocates
 120  *      memory for the dma controller "program" and then fills in that
 121  *      memory with the appropriate "instructions".
 122  *
 123  *      @pci_dev        structure with info about the pci
 124  *                      slot which our device is in.
 125  *      @risc           structure with info about the memory
 126  *                      used for our controller program.
 127  *      @sglist         scatter-gather list entry
 128  *      @top_offset     offset within the risc program area for the
 129  *                      first odd frame line
 130  *      @bottom_offset  offset within the risc program area for the
 131  *                      first even frame line
 132  *      @bpl            number of data bytes per scan line
 133  *      @padding        number of extra bytes to add at end of line
 134  *      @lines          number of scan lines
 135  */
 136 int tw68_risc_buffer(struct pci_dev *pci,
 137                         struct tw68_buf *buf,
 138                         struct scatterlist *sglist,
 139                         unsigned int top_offset,
 140                         unsigned int bottom_offset,
 141                         unsigned int bpl,
 142                         unsigned int padding,
 143                         unsigned int lines)
 144 {
 145         u32 instructions, fields;
 146         __le32 *rp;
 147
 148         fields = 0;
 149         if (UNSET != top_offset)
 150                 fields++;
 151         if (UNSET != bottom_offset)
 152                 fields++;
 153         /*
 154          * estimate risc mem: worst case is one write per page border +
 155          * one write per scan line + syncs + 2 jumps (all 2 dwords).
 156          * Padding can cause next bpl to start close to a page border.
 157          * First DMA region may be smaller than PAGE_SIZE
 158          */
 159         instructions  = fields * (1 + (((bpl + padding) * lines) /
 160                          PAGE_SIZE) + lines) + 4;
 161         buf->size = instructions * 8;
 162         buf->cpu = pci_alloc_consistent(pci, buf->size, &buf->dma);
 163         if (buf->cpu == NULL)
 164                 return -ENOMEM;
 165
 166         /* write risc instructions */
 167         rp = buf->cpu;
 168         if (UNSET != top_offset)        /* generates SYNCO */
 169                 rp = tw68_risc_field(rp, sglist, top_offset, 1,
 170                                      bpl, padding, lines, true);
 171         if (UNSET != bottom_offset)     /* generates SYNCE */
 172                 rp = tw68_risc_field(rp, sglist, bottom_offset, 2,
 173                                      bpl, padding, lines, top_offset == UNSET);
 174
 175         /* save pointer to jmp instruction address */
 176         buf->jmp = rp;
 177         buf->cpu[1] = cpu_to_le32(buf->dma + 8);
 178         /* assure risc buffer hasn't overflowed */
 179         BUG_ON((buf->jmp - buf->cpu + 2) * sizeof(buf->cpu[0]) > buf->size);
 180         return 0;
 181 }
 182
 183 #if 0
 184 /* ------------------------------------------------------------------ */
 185 /* debug helper code                                                  */
 186
 187 static void tw68_risc_decode(u32 risc, u32 addr)
 188 {
 189 #define RISC_OP(reg)    (((reg) >> 28) & 7)
 190         static struct instr_details {
 191                 char *name;
 192                 u8 has_data_type;
 193                 u8 has_byte_info;
 194                 u8 has_addr;
 195         } instr[8] = {
 196                 [RISC_OP(RISC_SYNCO)]     = {"syncOdd", 0, 0, 0},
 197                 [RISC_OP(RISC_SYNCE)]     = {"syncEven", 0, 0, 0},
 198                 [RISC_OP(RISC_JUMP)]      = {"jump", 0, 0, 1},
 199                 [RISC_OP(RISC_LINESTART)] = {"lineStart", 1, 1, 1},
 200                 [RISC_OP(RISC_INLINE)]    = {"inline", 1, 1, 1},
 201         };
 202         u32 p;
 203
 204         p = RISC_OP(risc);
 205         if (!(risc & 0x80000000) || !instr[p].name) {
 206                 pr_debug("0x%08x [ INVALID ]\n", risc);
 207                 return;
 208         }
 209         pr_debug("0x%08x %-9s IRQ=%d",
 210                 risc, instr[p].name, (risc >> 27) & 1);
 211         if (instr[p].has_data_type)
 212                 pr_debug(" Type=%d", (risc >> 24) & 7);
 213         if (instr[p].has_byte_info)
 214                 pr_debug(" Start=0x%03x Count=%03u",
 215                         (risc >> 12) & 0xfff, risc & 0xfff);
 216         if (instr[p].has_addr)
 217                 pr_debug(" StartAddr=0x%08x", addr);
 218         pr_debug("\n");
 219 }
 220
 221 void tw68_risc_program_dump(struct tw68_core *core, struct tw68_buf *buf)
 222 {
 223         const __le32 *addr;
 224
 225         pr_debug("%s: risc_program_dump: risc=%p, buf->cpu=0x%p, buf->jmp=0x%p\n",
 226                   core->name, buf, buf->cpu, buf->jmp);
 227         for (addr = buf->cpu; addr <= buf->jmp; addr += 2)
 228                 tw68_risc_decode(*addr, *(addr+1));
 229 }
 230 #endif