diff options
Diffstat (limited to 'drivers/media/pci/tw68/tw68-risc.c')
| -rw-r--r-- | drivers/media/pci/tw68/tw68-risc.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/media/pci/tw68/tw68-risc.c b/drivers/media/pci/tw68/tw68-risc.c new file mode 100644 index 0000000000..dacb136c4f --- /dev/null +++ b/drivers/media/pci/tw68/tw68-risc.c @@ -0,0 +1,223 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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> + */ + +#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 = dma_alloc_coherent(&pci->dev, buf->size, &buf->dma, + GFP_KERNEL); + 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 |