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   1 /*
   2  * driver/dma/coh901318_lli.c
   3  *
   4  * Copyright (C) 2007-2009 ST-Ericsson
   5  * License terms: GNU General Public License (GPL) version 2
   6  * Support functions for handling lli for dma
   7  * Author: Per Friden <per.friden@stericsson.com>
   8  */
   9
  10 #include <linux/dma-mapping.h>
  11 #include <linux/spinlock.h>
  12 #include <linux/dmapool.h>
  13 #include <linux/memory.h>
  14 #include <linux/gfp.h>
  15 #include <mach/coh901318.h>
  16
  17 #include "coh901318_lli.h"
  18
  19 #if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_U300_DEBUG))
  20 #define DEBUGFS_POOL_COUNTER_RESET(pool) (pool->debugfs_pool_counter = 0)
  21 #define DEBUGFS_POOL_COUNTER_ADD(pool, add) (pool->debugfs_pool_counter += add)
  22 #else
  23 #define DEBUGFS_POOL_COUNTER_RESET(pool)
  24 #define DEBUGFS_POOL_COUNTER_ADD(pool, add)
  25 #endif
  26
  27 static struct coh901318_lli *
  28 coh901318_lli_next(struct coh901318_lli *data)
  29 {
  30         if (data == NULL || data->link_addr == 0)
  31                 return NULL;
  32
  33         return (struct coh901318_lli *) data->virt_link_addr;
  34 }
  35
  36 int coh901318_pool_create(struct coh901318_pool *pool,
  37                           struct device *dev,
  38                           size_t size, size_t align)
  39 {
  40         spin_lock_init(&pool->lock);
  41         pool->dev = dev;
  42         pool->dmapool = dma_pool_create("lli_pool", dev, size, align, 0);
  43
  44         DEBUGFS_POOL_COUNTER_RESET(pool);
  45         return 0;
  46 }
  47
  48 int coh901318_pool_destroy(struct coh901318_pool *pool)
  49 {
  50
  51         dma_pool_destroy(pool->dmapool);
  52         return 0;
  53 }
  54
  55 struct coh901318_lli *
  56 coh901318_lli_alloc(struct coh901318_pool *pool, unsigned int len)
  57 {
  58         int i;
  59         struct coh901318_lli *head;
  60         struct coh901318_lli *lli;
  61         struct coh901318_lli *lli_prev;
  62         dma_addr_t phy;
  63
  64         if (len == 0)
  65                 goto err;
  66
  67         spin_lock(&pool->lock);
  68
  69         head = dma_pool_alloc(pool->dmapool, GFP_NOWAIT, &phy);
  70
  71         if (head == NULL)
  72                 goto err;
  73
  74         DEBUGFS_POOL_COUNTER_ADD(pool, 1);
  75
  76         lli = head;
  77         lli->phy_this = phy;
  78         lli->link_addr = 0x00000000;
  79         lli->virt_link_addr = 0x00000000U;
  80
  81         for (i = 1; i < len; i++) {
  82                 lli_prev = lli;
  83
  84                 lli = dma_pool_alloc(pool->dmapool, GFP_NOWAIT, &phy);
  85
  86                 if (lli == NULL)
  87                         goto err_clean_up;
  88
  89                 DEBUGFS_POOL_COUNTER_ADD(pool, 1);
  90                 lli->phy_this = phy;
  91                 lli->link_addr = 0x00000000;
  92                 lli->virt_link_addr = 0x00000000U;
  93
  94                 lli_prev->link_addr = phy;
  95                 lli_prev->virt_link_addr = lli;
  96         }
  97
  98         spin_unlock(&pool->lock);
  99
 100         return head;
 101
 102  err:
 103         spin_unlock(&pool->lock);
 104         return NULL;
 105
 106  err_clean_up:
 107         lli_prev->link_addr = 0x00000000U;
 108         spin_unlock(&pool->lock);
 109         coh901318_lli_free(pool, &head);
 110         return NULL;
 111 }
 112
 113 void coh901318_lli_free(struct coh901318_pool *pool,
 114                         struct coh901318_lli **lli)
 115 {
 116         struct coh901318_lli *l;
 117         struct coh901318_lli *next;
 118
 119         if (lli == NULL)
 120                 return;
 121
 122         l = *lli;
 123
 124         if (l == NULL)
 125                 return;
 126
 127         spin_lock(&pool->lock);
 128
 129         while (l->link_addr) {
 130                 next = l->virt_link_addr;
 131                 dma_pool_free(pool->dmapool, l, l->phy_this);
 132                 DEBUGFS_POOL_COUNTER_ADD(pool, -1);
 133                 l = next;
 134         }
 135         dma_pool_free(pool->dmapool, l, l->phy_this);
 136         DEBUGFS_POOL_COUNTER_ADD(pool, -1);
 137
 138         spin_unlock(&pool->lock);
 139         *lli = NULL;
 140 }
 141
 142 int
 143 coh901318_lli_fill_memcpy(struct coh901318_pool *pool,
 144                           struct coh901318_lli *lli,
 145                           dma_addr_t source, unsigned int size,
 146                           dma_addr_t destination, u32 ctrl_chained,
 147                           u32 ctrl_eom)
 148 {
 149         int s = size;
 150         dma_addr_t src = source;
 151         dma_addr_t dst = destination;
 152
 153         lli->src_addr = src;
 154         lli->dst_addr = dst;
 155
 156         while (lli->link_addr) {
 157                 lli->control = ctrl_chained | MAX_DMA_PACKET_SIZE;
 158                 lli->src_addr = src;
 159                 lli->dst_addr = dst;
 160
 161                 s -= MAX_DMA_PACKET_SIZE;
 162                 lli = coh901318_lli_next(lli);
 163
 164                 src += MAX_DMA_PACKET_SIZE;
 165                 dst += MAX_DMA_PACKET_SIZE;
 166         }
 167
 168         lli->control = ctrl_eom | s;
 169         lli->src_addr = src;
 170         lli->dst_addr = dst;
 171
 172         return 0;
 173 }
 174
 175 int
 176 coh901318_lli_fill_single(struct coh901318_pool *pool,
 177                           struct coh901318_lli *lli,
 178                           dma_addr_t buf, unsigned int size,
 179                           dma_addr_t dev_addr, u32 ctrl_chained, u32 ctrl_eom,
 180                           enum dma_data_direction dir)
 181 {
 182         int s = size;
 183         dma_addr_t src;
 184         dma_addr_t dst;
 185
 186
 187         if (dir == DMA_TO_DEVICE) {
 188                 src = buf;
 189                 dst = dev_addr;
 190
 191         } else if (dir == DMA_FROM_DEVICE) {
 192
 193                 src = dev_addr;
 194                 dst = buf;
 195         } else {
 196                 return -EINVAL;
 197         }
 198
 199         while (lli->link_addr) {
 200                 size_t block_size = MAX_DMA_PACKET_SIZE;
 201                 lli->control = ctrl_chained | MAX_DMA_PACKET_SIZE;
 202
 203                 /* If we are on the next-to-final block and there will
 204                  * be less than half a DMA packet left for the last
 205                  * block, then we want to make this block a little
 206                  * smaller to balance the sizes. This is meant to
 207                  * avoid too small transfers if the buffer size is
 208                  * (MAX_DMA_PACKET_SIZE*N + 1) */
 209                 if (s < (MAX_DMA_PACKET_SIZE + MAX_DMA_PACKET_SIZE/2))
 210                         block_size = MAX_DMA_PACKET_SIZE/2;
 211
 212                 s -= block_size;
 213                 lli->src_addr = src;
 214                 lli->dst_addr = dst;
 215
 216                 lli = coh901318_lli_next(lli);
 217
 218                 if (dir == DMA_TO_DEVICE)
 219                         src += block_size;
 220                 else if (dir == DMA_FROM_DEVICE)
 221                         dst += block_size;
 222         }
 223
 224         lli->control = ctrl_eom | s;
 225         lli->src_addr = src;
 226         lli->dst_addr = dst;
 227
 228         return 0;
 229 }
 230
 231 int
 232 coh901318_lli_fill_sg(struct coh901318_pool *pool,
 233                       struct coh901318_lli *lli,
 234                       struct scatterlist *sgl, unsigned int nents,
 235                       dma_addr_t dev_addr, u32 ctrl_chained, u32 ctrl,
 236                       u32 ctrl_last,
 237                       enum dma_data_direction dir, u32 ctrl_irq_mask)
 238 {
 239         int i;
 240         struct scatterlist *sg;
 241         u32 ctrl_sg;
 242         dma_addr_t src = 0;
 243         dma_addr_t dst = 0;
 244         u32 bytes_to_transfer;
 245         u32 elem_size;
 246
 247         if (lli == NULL)
 248                 goto err;
 249
 250         spin_lock(&pool->lock);
 251
 252         if (dir == DMA_TO_DEVICE)
 253                 dst = dev_addr;
 254         else if (dir == DMA_FROM_DEVICE)
 255                 src = dev_addr;
 256         else
 257                 goto err;
 258
 259         for_each_sg(sgl, sg, nents, i) {
 260                 if (sg_is_chain(sg)) {
 261                         /* sg continues to the next sg-element don't
 262                          * send ctrl_finish until the last
 263                          * sg-element in the chain
 264                          */
 265                         ctrl_sg = ctrl_chained;
 266                 } else if (i == nents - 1)
 267                         ctrl_sg = ctrl_last;
 268                 else
 269                         ctrl_sg = ctrl ? ctrl : ctrl_last;
 270
 271
 272                 if (dir == DMA_TO_DEVICE)
 273                         /* increment source address */
 274                         src = sg_phys(sg);
 275                 else
 276                         /* increment destination address */
 277                         dst =  sg_phys(sg);
 278
 279                 bytes_to_transfer = sg_dma_len(sg);
 280
 281                 while (bytes_to_transfer) {
 282                         u32 val;
 283
 284                         if (bytes_to_transfer > MAX_DMA_PACKET_SIZE) {
 285                                 elem_size = MAX_DMA_PACKET_SIZE;
 286                                 val = ctrl_chained;
 287                         } else {
 288                                 elem_size = bytes_to_transfer;
 289                                 val = ctrl_sg;
 290                         }
 291
 292                         lli->control = val | elem_size;
 293                         lli->src_addr = src;
 294                         lli->dst_addr = dst;
 295
 296                         if (dir == DMA_FROM_DEVICE)
 297                                 dst += elem_size;
 298                         else
 299                                 src += elem_size;
 300
 301                         BUG_ON(lli->link_addr & 3);
 302
 303                         bytes_to_transfer -= elem_size;
 304                         lli = coh901318_lli_next(lli);
 305                 }
 306
 307         }
 308         spin_unlock(&pool->lock);
 309
 310         return 0;
 311  err:
 312         spin_unlock(&pool->lock);
 313         return -EINVAL;
 314 }