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  * tw68_risc_field
  33  *  @rp:        pointer to current risc program position
  34  *  @sglist:    pointer to "scatter-gather list" of buffer pointers
  35  *  @offset:    offset to target memory buffer
  36  *  @sync_line: 0 -> no sync, 1 -> odd sync, 2 -> even sync
  37  *  @bpl:       number of bytes per scan line
  38  *  @padding:   number of bytes of padding to add
  39  *  @lines:     number of lines in field
  40  *  @jump:      insert a jump at the start
  41  */
  42 static __le32 *tw68_risc_field(__le32 *rp, struct scatterlist *sglist,
  43                             unsigned int offset, u32 sync_line,
  44                             unsigned int bpl, unsigned int padding,
  45                             unsigned int lines, bool jump)
  46 {
  47         struct scatterlist *sg;
  48         unsigned int line, todo, done;
  49
  50         if (jump) {
  51                 *(rp++) = cpu_to_le32(RISC_JUMP);
  52                 *(rp++) = 0;
  53         }
  54
  55         /* sync instruction */
  56         if (sync_line == 1)
  57                 *(rp++) = cpu_to_le32(RISC_SYNCO);
  58         else
  59                 *(rp++) = cpu_to_le32(RISC_SYNCE);
  60         *(rp++) = 0;
  61
  62         /* scan lines */
  63         sg = sglist;
  64         for (line = 0; line < lines; line++) {
  65                 /* calculate next starting position */
  66                 while (offset && offset >= sg_dma_len(sg)) {
  67                         offset -= sg_dma_len(sg);
  68                         sg = sg_next(sg);
  69                 }
  70                 if (bpl <= sg_dma_len(sg) - offset) {
  71                         /* fits into current chunk */
  72                         *(rp++) = cpu_to_le32(RISC_LINESTART |
  73                                               /* (offset<<12) |*/  bpl);
  74                         *(rp++) = cpu_to_le32(sg_dma_address(sg) + offset);
  75                         offset += bpl;
  76                 } else {
  77                         /*
  78                          * scanline needs to be split.  Put the start in
  79                          * whatever memory remains using RISC_LINESTART,
  80                          * then the remainder into following addresses
  81                          * given by the scatter-gather list.
  82                          */
  83                         todo = bpl;     /* one full line to be done */
  84                         /* first fragment */
  85                         done = (sg_dma_len(sg) - offset);
  86                         *(rp++) = cpu_to_le32(RISC_LINESTART |
  87                                                 (7 << 24) |
  88                                                 done);
  89                         *(rp++) = cpu_to_le32(sg_dma_address(sg) + offset);
  90                         todo -= done;
  91                         sg = sg_next(sg);
  92                         /* succeeding fragments have no offset */
  93                         while (todo > sg_dma_len(sg)) {
  94                                 *(rp++) = cpu_to_le32(RISC_INLINE |
  95                                                 (done << 12) |
  96                                                 sg_dma_len(sg));
  97                                 *(rp++) = cpu_to_le32(sg_dma_address(sg));
  98                                 todo -= sg_dma_len(sg);
  99                                 sg = sg_next(sg);
 100                                 done += sg_dma_len(sg);
 101                         }
 102                         if (todo) {
 103                                 /* final chunk - offset 0, count 'todo' */
 104                                 *(rp++) = cpu_to_le32(RISC_INLINE |
 105                                                         (done << 12) |
 106                                                         todo);
 107                                 *(rp++) = cpu_to_le32(sg_dma_address(sg));
 108                         }
 109                         offset = todo;
 110                 }
 111                 offset += padding;
 112         }
 113
 114         return rp;
 115 }
 116
 117 /**
 118  * tw68_risc_buffer
 119  *
 120  *      This routine is called by tw68-video.  It allocates
 121  *      memory for the dma controller "program" and then fills in that
 122  *      memory with the appropriate "instructions".
 123  *
 124  *      @pci:           structure with info about the pci
 125  *                      slot which our device is in.
 126  *      @buf:           structure with info about the memory
 127  *                      used for our controller program.
 128  *      @sglist:        scatter-gather list entry
 129  *      @top_offset:    offset within the risc program area for the
 130  *                      first odd frame line
 131  *      @bottom_offset: offset within the risc program area for the
 132  *                      first even frame line
 133  *      @bpl:           number of data bytes per scan line
 134  *      @padding:       number of extra bytes to add at end of line
 135  *      @lines:         number of scan lines
 136  */
 137 int tw68_risc_buffer(struct pci_dev *pci,
 138                         struct tw68_buf *buf,
 139                         struct scatterlist *sglist,
 140                         unsigned int top_offset,
 141                         unsigned int bottom_offset,
 142                         unsigned int bpl,
 143                         unsigned int padding,
 144                         unsigned int lines)
 145 {
 146         u32 instructions, fields;
 147         __le32 *rp;
 148
 149         fields = 0;
 150         if (UNSET != top_offset)
 151                 fields++;
 152         if (UNSET != bottom_offset)
 153                 fields++;
 154         /*
 155          * estimate risc mem: worst case is one write per page border +
 156          * one write per scan line + syncs + 2 jumps (all 2 dwords).
 157          * Padding can cause next bpl to start close to a page border.
 158          * First DMA region may be smaller than PAGE_SIZE
 159          */
 160         instructions  = fields * (1 + (((bpl + padding) * lines) /
 161                          PAGE_SIZE) + lines) + 4;
 162         buf->size = instructions * 8;
 163         buf->cpu = pci_alloc_consistent(pci, buf->size, &buf->dma);
 164         if (buf->cpu == NULL)
 165                 return -ENOMEM;
 166
 167         /* write risc instructions */
 168         rp = buf->cpu;
 169         if (UNSET != top_offset)        /* generates SYNCO */
 170                 rp = tw68_risc_field(rp, sglist, top_offset, 1,
 171                                      bpl, padding, lines, true);
 172         if (UNSET != bottom_offset)     /* generates SYNCE */
 173                 rp = tw68_risc_field(rp, sglist, bottom_offset, 2,
 174                                      bpl, padding, lines, top_offset == UNSET);
 175
 176         /* save pointer to jmp instruction address */
 177         buf->jmp = rp;
 178         buf->cpu[1] = cpu_to_le32(buf->dma + 8);
 179         /* assure risc buffer hasn't overflowed */
 180         BUG_ON((buf->jmp - buf->cpu + 2) * sizeof(buf->cpu[0]) > buf->size);
 181         return 0;
 182 }
 183
 184 #if 0
 185 /* ------------------------------------------------------------------ */
 186 /* debug helper code                                                  */
 187
 188 static void tw68_risc_decode(u32 risc, u32 addr)
 189 {
 190 #define RISC_OP(reg)    (((reg) >> 28) & 7)
 191         static struct instr_details {
 192                 char *name;
 193                 u8 has_data_type;
 194                 u8 has_byte_info;
 195                 u8 has_addr;
 196         } instr[8] = {
 197                 [RISC_OP(RISC_SYNCO)]     = {"syncOdd", 0, 0, 0},
 198                 [RISC_OP(RISC_SYNCE)]     = {"syncEven", 0, 0, 0},
 199                 [RISC_OP(RISC_JUMP)]      = {"jump", 0, 0, 1},
 200                 [RISC_OP(RISC_LINESTART)] = {"lineStart", 1, 1, 1},
 201                 [RISC_OP(RISC_INLINE)]    = {"inline", 1, 1, 1},
 202         };
 203         u32 p;
 204
 205         p = RISC_OP(risc);
 206         if (!(risc & 0x80000000) || !instr[p].name) {
 207                 pr_debug("0x%08x [ INVALID ]\n", risc);
 208                 return;
 209         }
 210         pr_debug("0x%08x %-9s IRQ=%d",
 211                 risc, instr[p].name, (risc >> 27) & 1);
 212         if (instr[p].has_data_type)
 213                 pr_debug(" Type=%d", (risc >> 24) & 7);
 214         if (instr[p].has_byte_info)
 215                 pr_debug(" Start=0x%03x Count=%03u",
 216                         (risc >> 12) & 0xfff, risc & 0xfff);
 217         if (instr[p].has_addr)
 218                 pr_debug(" StartAddr=0x%08x", addr);
 219         pr_debug("\n");
 220 }
 221
 222 void tw68_risc_program_dump(struct tw68_core *core, struct tw68_buf *buf)
 223 {
 224         const __le32 *addr;
 225
 226         pr_debug("%s: risc_program_dump: risc=%p, buf->cpu=0x%p, buf->jmp=0x%p\n",
 227                   core->name, buf, buf->cpu, buf->jmp);
 228         for (addr = buf->cpu; addr <= buf->jmp; addr += 2)
 229                 tw68_risc_decode(*addr, *(addr+1));
 230 }
 231 #endif