tw68-risc.c (6605B)
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * tw68_risc.c 4 * Part of the device driver for Techwell 68xx based cards 5 * 6 * Much of this code is derived from the cx88 and sa7134 drivers, which 7 * were in turn derived from the bt87x driver. The original work was by 8 * Gerd Knorr; more recently the code was enhanced by Mauro Carvalho Chehab, 9 * Hans Verkuil, Andy Walls and many others. Their work is gratefully 10 * acknowledged. Full credit goes to them - any problems within this code 11 * are mine. 12 * 13 * Copyright (C) 2009 William M. Brack 14 * 15 * Refactored and updated to the latest v4l core frameworks: 16 * 17 * Copyright (C) 2014 Hans Verkuil <hverkuil@xs4all.nl> 18 */ 19 20#include "tw68.h" 21 22/** 23 * tw68_risc_field 24 * @rp: pointer to current risc program position 25 * @sglist: pointer to "scatter-gather list" of buffer pointers 26 * @offset: offset to target memory buffer 27 * @sync_line: 0 -> no sync, 1 -> odd sync, 2 -> even sync 28 * @bpl: number of bytes per scan line 29 * @padding: number of bytes of padding to add 30 * @lines: number of lines in field 31 * @jump: insert a jump at the start 32 */ 33static __le32 *tw68_risc_field(__le32 *rp, struct scatterlist *sglist, 34 unsigned int offset, u32 sync_line, 35 unsigned int bpl, unsigned int padding, 36 unsigned int lines, bool jump) 37{ 38 struct scatterlist *sg; 39 unsigned int line, todo, done; 40 41 if (jump) { 42 *(rp++) = cpu_to_le32(RISC_JUMP); 43 *(rp++) = 0; 44 } 45 46 /* sync instruction */ 47 if (sync_line == 1) 48 *(rp++) = cpu_to_le32(RISC_SYNCO); 49 else 50 *(rp++) = cpu_to_le32(RISC_SYNCE); 51 *(rp++) = 0; 52 53 /* scan lines */ 54 sg = sglist; 55 for (line = 0; line < lines; line++) { 56 /* calculate next starting position */ 57 while (offset && offset >= sg_dma_len(sg)) { 58 offset -= sg_dma_len(sg); 59 sg = sg_next(sg); 60 } 61 if (bpl <= sg_dma_len(sg) - offset) { 62 /* fits into current chunk */ 63 *(rp++) = cpu_to_le32(RISC_LINESTART | 64 /* (offset<<12) |*/ bpl); 65 *(rp++) = cpu_to_le32(sg_dma_address(sg) + offset); 66 offset += bpl; 67 } else { 68 /* 69 * scanline needs to be split. Put the start in 70 * whatever memory remains using RISC_LINESTART, 71 * then the remainder into following addresses 72 * given by the scatter-gather list. 73 */ 74 todo = bpl; /* one full line to be done */ 75 /* first fragment */ 76 done = (sg_dma_len(sg) - offset); 77 *(rp++) = cpu_to_le32(RISC_LINESTART | 78 (7 << 24) | 79 done); 80 *(rp++) = cpu_to_le32(sg_dma_address(sg) + offset); 81 todo -= done; 82 sg = sg_next(sg); 83 /* succeeding fragments have no offset */ 84 while (todo > sg_dma_len(sg)) { 85 *(rp++) = cpu_to_le32(RISC_INLINE | 86 (done << 12) | 87 sg_dma_len(sg)); 88 *(rp++) = cpu_to_le32(sg_dma_address(sg)); 89 todo -= sg_dma_len(sg); 90 sg = sg_next(sg); 91 done += sg_dma_len(sg); 92 } 93 if (todo) { 94 /* final chunk - offset 0, count 'todo' */ 95 *(rp++) = cpu_to_le32(RISC_INLINE | 96 (done << 12) | 97 todo); 98 *(rp++) = cpu_to_le32(sg_dma_address(sg)); 99 } 100 offset = todo; 101 } 102 offset += padding; 103 } 104 105 return rp; 106} 107 108/** 109 * tw68_risc_buffer 110 * 111 * This routine is called by tw68-video. It allocates 112 * memory for the dma controller "program" and then fills in that 113 * memory with the appropriate "instructions". 114 * 115 * @pci: structure with info about the pci 116 * slot which our device is in. 117 * @buf: structure with info about the memory 118 * used for our controller program. 119 * @sglist: scatter-gather list entry 120 * @top_offset: offset within the risc program area for the 121 * first odd frame line 122 * @bottom_offset: offset within the risc program area for the 123 * first even frame line 124 * @bpl: number of data bytes per scan line 125 * @padding: number of extra bytes to add at end of line 126 * @lines: number of scan lines 127 */ 128int tw68_risc_buffer(struct pci_dev *pci, 129 struct tw68_buf *buf, 130 struct scatterlist *sglist, 131 unsigned int top_offset, 132 unsigned int bottom_offset, 133 unsigned int bpl, 134 unsigned int padding, 135 unsigned int lines) 136{ 137 u32 instructions, fields; 138 __le32 *rp; 139 140 fields = 0; 141 if (UNSET != top_offset) 142 fields++; 143 if (UNSET != bottom_offset) 144 fields++; 145 /* 146 * estimate risc mem: worst case is one write per page border + 147 * one write per scan line + syncs + 2 jumps (all 2 dwords). 148 * Padding can cause next bpl to start close to a page border. 149 * First DMA region may be smaller than PAGE_SIZE 150 */ 151 instructions = fields * (1 + (((bpl + padding) * lines) / 152 PAGE_SIZE) + lines) + 4; 153 buf->size = instructions * 8; 154 buf->cpu = dma_alloc_coherent(&pci->dev, buf->size, &buf->dma, 155 GFP_KERNEL); 156 if (buf->cpu == NULL) 157 return -ENOMEM; 158 159 /* write risc instructions */ 160 rp = buf->cpu; 161 if (UNSET != top_offset) /* generates SYNCO */ 162 rp = tw68_risc_field(rp, sglist, top_offset, 1, 163 bpl, padding, lines, true); 164 if (UNSET != bottom_offset) /* generates SYNCE */ 165 rp = tw68_risc_field(rp, sglist, bottom_offset, 2, 166 bpl, padding, lines, top_offset == UNSET); 167 168 /* save pointer to jmp instruction address */ 169 buf->jmp = rp; 170 buf->cpu[1] = cpu_to_le32(buf->dma + 8); 171 /* assure risc buffer hasn't overflowed */ 172 BUG_ON((buf->jmp - buf->cpu + 2) * sizeof(buf->cpu[0]) > buf->size); 173 return 0; 174} 175 176#if 0 177/* ------------------------------------------------------------------ */ 178/* debug helper code */ 179 180static void tw68_risc_decode(u32 risc, u32 addr) 181{ 182#define RISC_OP(reg) (((reg) >> 28) & 7) 183 static struct instr_details { 184 char *name; 185 u8 has_data_type; 186 u8 has_byte_info; 187 u8 has_addr; 188 } instr[8] = { 189 [RISC_OP(RISC_SYNCO)] = {"syncOdd", 0, 0, 0}, 190 [RISC_OP(RISC_SYNCE)] = {"syncEven", 0, 0, 0}, 191 [RISC_OP(RISC_JUMP)] = {"jump", 0, 0, 1}, 192 [RISC_OP(RISC_LINESTART)] = {"lineStart", 1, 1, 1}, 193 [RISC_OP(RISC_INLINE)] = {"inline", 1, 1, 1}, 194 }; 195 u32 p; 196 197 p = RISC_OP(risc); 198 if (!(risc & 0x80000000) || !instr[p].name) { 199 pr_debug("0x%08x [ INVALID ]\n", risc); 200 return; 201 } 202 pr_debug("0x%08x %-9s IRQ=%d", 203 risc, instr[p].name, (risc >> 27) & 1); 204 if (instr[p].has_data_type) 205 pr_debug(" Type=%d", (risc >> 24) & 7); 206 if (instr[p].has_byte_info) 207 pr_debug(" Start=0x%03x Count=%03u", 208 (risc >> 12) & 0xfff, risc & 0xfff); 209 if (instr[p].has_addr) 210 pr_debug(" StartAddr=0x%08x", addr); 211 pr_debug("\n"); 212} 213 214void tw68_risc_program_dump(struct tw68_core *core, struct tw68_buf *buf) 215{ 216 const __le32 *addr; 217 218 pr_debug("%s: risc_program_dump: risc=%p, buf->cpu=0x%p, buf->jmp=0x%p\n", 219 core->name, buf, buf->cpu, buf->jmp); 220 for (addr = buf->cpu; addr <= buf->jmp; addr += 2) 221 tw68_risc_decode(*addr, *(addr+1)); 222} 223#endif