dma-ops.c 3.6 KB

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  1. /* linux/arch/arm/plat-samsung/dma-ops.c
  2. *
  3. * Copyright (c) 2011 Samsung Electronics Co., Ltd.
  4. * http://www.samsung.com
  5. *
  6. * Samsung DMA Operations
  7. *
  8. * This program is free software; you can redistribute it and/or modify
  9. * it under the terms of the GNU General Public License version 2 as
  10. * published by the Free Software Foundation.
  11. */
  12. #include <linux/kernel.h>
  13. #include <linux/errno.h>
  14. #include <linux/amba/pl330.h>
  15. #include <linux/scatterlist.h>
  16. #include <linux/export.h>
  17. #include <mach/dma.h>
  18. static unsigned samsung_dmadev_request(enum dma_ch dma_ch,
  19. struct samsung_dma_req *param)
  20. {
  21. dma_cap_mask_t mask;
  22. void *filter_param;
  23. dma_cap_zero(mask);
  24. dma_cap_set(param->cap, mask);
  25. /*
  26. * If a dma channel property of a device node from device tree is
  27. * specified, use that as the fliter parameter.
  28. */
  29. filter_param = (dma_ch == DMACH_DT_PROP) ?
  30. (void *)param->dt_dmach_prop : (void *)dma_ch;
  31. return (unsigned)dma_request_channel(mask, pl330_filter, filter_param);
  32. }
  33. static int samsung_dmadev_release(unsigned ch, void *param)
  34. {
  35. dma_release_channel((struct dma_chan *)ch);
  36. return 0;
  37. }
  38. static int samsung_dmadev_config(unsigned ch,
  39. struct samsung_dma_config *param)
  40. {
  41. struct dma_chan *chan = (struct dma_chan *)ch;
  42. struct dma_slave_config slave_config;
  43. if (param->direction == DMA_DEV_TO_MEM) {
  44. memset(&slave_config, 0, sizeof(struct dma_slave_config));
  45. slave_config.direction = param->direction;
  46. slave_config.src_addr = param->fifo;
  47. slave_config.src_addr_width = param->width;
  48. slave_config.src_maxburst = 1;
  49. dmaengine_slave_config(chan, &slave_config);
  50. } else if (param->direction == DMA_MEM_TO_DEV) {
  51. memset(&slave_config, 0, sizeof(struct dma_slave_config));
  52. slave_config.direction = param->direction;
  53. slave_config.dst_addr = param->fifo;
  54. slave_config.dst_addr_width = param->width;
  55. slave_config.dst_maxburst = 1;
  56. dmaengine_slave_config(chan, &slave_config);
  57. } else {
  58. pr_warn("unsupported direction\n");
  59. return -EINVAL;
  60. }
  61. return 0;
  62. }
  63. static int samsung_dmadev_prepare(unsigned ch,
  64. struct samsung_dma_prep *param)
  65. {
  66. struct scatterlist sg;
  67. struct dma_chan *chan = (struct dma_chan *)ch;
  68. struct dma_async_tx_descriptor *desc;
  69. switch (param->cap) {
  70. case DMA_SLAVE:
  71. sg_init_table(&sg, 1);
  72. sg_dma_len(&sg) = param->len;
  73. sg_set_page(&sg, pfn_to_page(PFN_DOWN(param->buf)),
  74. param->len, offset_in_page(param->buf));
  75. sg_dma_address(&sg) = param->buf;
  76. desc = dmaengine_prep_slave_sg(chan,
  77. &sg, 1, param->direction, DMA_PREP_INTERRUPT);
  78. break;
  79. case DMA_CYCLIC:
  80. desc = dmaengine_prep_dma_cyclic(chan, param->buf,
  81. param->len, param->period, param->direction);
  82. break;
  83. default:
  84. dev_err(&chan->dev->device, "unsupported format\n");
  85. return -EFAULT;
  86. }
  87. if (!desc) {
  88. dev_err(&chan->dev->device, "cannot prepare cyclic dma\n");
  89. return -EFAULT;
  90. }
  91. desc->callback = param->fp;
  92. desc->callback_param = param->fp_param;
  93. dmaengine_submit((struct dma_async_tx_descriptor *)desc);
  94. return 0;
  95. }
  96. static inline int samsung_dmadev_trigger(unsigned ch)
  97. {
  98. dma_async_issue_pending((struct dma_chan *)ch);
  99. return 0;
  100. }
  101. static inline int samsung_dmadev_flush(unsigned ch)
  102. {
  103. return dmaengine_terminate_all((struct dma_chan *)ch);
  104. }
  105. static struct samsung_dma_ops dmadev_ops = {
  106. .request = samsung_dmadev_request,
  107. .release = samsung_dmadev_release,
  108. .config = samsung_dmadev_config,
  109. .prepare = samsung_dmadev_prepare,
  110. .trigger = samsung_dmadev_trigger,
  111. .started = NULL,
  112. .flush = samsung_dmadev_flush,
  113. .stop = samsung_dmadev_flush,
  114. };
  115. void *samsung_dmadev_get_ops(void)
  116. {
  117. return &dmadev_ops;
  118. }
  119. EXPORT_SYMBOL(samsung_dmadev_get_ops);