/*
* 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"
/**
* tw68_risc_field
* @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: structure with info about the pci
* slot which our device is in.
* @buf: 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
