dw.c 3.6 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. // Copyright (C) 2007-2008 Atmel Corporation
  3. // Copyright (C) 2010-2011 ST Microelectronics
  4. // Copyright (C) 2013,2018 Intel Corporation
  5. #include <linux/bitops.h>
  6. #include <linux/dmaengine.h>
  7. #include <linux/errno.h>
  8. #include <linux/slab.h>
  9. #include <linux/types.h>
  10. #include "internal.h"
  11. static void dw_dma_initialize_chan(struct dw_dma_chan *dwc)
  12. {
  13. struct dw_dma *dw = to_dw_dma(dwc->chan.device);
  14. u32 cfghi = is_slave_direction(dwc->direction) ? 0 : DWC_CFGH_FIFO_MODE;
  15. u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
  16. bool hs_polarity = dwc->dws.hs_polarity;
  17. cfghi |= DWC_CFGH_DST_PER(dwc->dws.dst_id);
  18. cfghi |= DWC_CFGH_SRC_PER(dwc->dws.src_id);
  19. cfghi |= DWC_CFGH_PROTCTL(dw->pdata->protctl);
  20. /* Set polarity of handshake interface */
  21. cfglo |= hs_polarity ? DWC_CFGL_HS_DST_POL | DWC_CFGL_HS_SRC_POL : 0;
  22. channel_writel(dwc, CFG_LO, cfglo);
  23. channel_writel(dwc, CFG_HI, cfghi);
  24. }
  25. static void dw_dma_suspend_chan(struct dw_dma_chan *dwc, bool drain)
  26. {
  27. u32 cfglo = channel_readl(dwc, CFG_LO);
  28. channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
  29. }
  30. static void dw_dma_resume_chan(struct dw_dma_chan *dwc, bool drain)
  31. {
  32. u32 cfglo = channel_readl(dwc, CFG_LO);
  33. channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
  34. }
  35. static u32 dw_dma_bytes2block(struct dw_dma_chan *dwc,
  36. size_t bytes, unsigned int width, size_t *len)
  37. {
  38. u32 block;
  39. if ((bytes >> width) > dwc->block_size) {
  40. block = dwc->block_size;
  41. *len = dwc->block_size << width;
  42. } else {
  43. block = bytes >> width;
  44. *len = bytes;
  45. }
  46. return block;
  47. }
  48. static size_t dw_dma_block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
  49. {
  50. return DWC_CTLH_BLOCK_TS(block) << width;
  51. }
  52. static u32 dw_dma_prepare_ctllo(struct dw_dma_chan *dwc)
  53. {
  54. struct dma_slave_config *sconfig = &dwc->dma_sconfig;
  55. u8 smsize = (dwc->direction == DMA_DEV_TO_MEM) ? sconfig->src_maxburst : 0;
  56. u8 dmsize = (dwc->direction == DMA_MEM_TO_DEV) ? sconfig->dst_maxburst : 0;
  57. u8 p_master = dwc->dws.p_master;
  58. u8 m_master = dwc->dws.m_master;
  59. u8 dms = (dwc->direction == DMA_MEM_TO_DEV) ? p_master : m_master;
  60. u8 sms = (dwc->direction == DMA_DEV_TO_MEM) ? p_master : m_master;
  61. return DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN |
  62. DWC_CTLL_DST_MSIZE(dmsize) | DWC_CTLL_SRC_MSIZE(smsize) |
  63. DWC_CTLL_DMS(dms) | DWC_CTLL_SMS(sms);
  64. }
  65. static void dw_dma_encode_maxburst(struct dw_dma_chan *dwc, u32 *maxburst)
  66. {
  67. /*
  68. * Fix burst size according to dw_dmac. We need to convert them as:
  69. * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
  70. */
  71. *maxburst = *maxburst > 1 ? fls(*maxburst) - 2 : 0;
  72. }
  73. static void dw_dma_set_device_name(struct dw_dma *dw, int id)
  74. {
  75. snprintf(dw->name, sizeof(dw->name), "dw:dmac%d", id);
  76. }
  77. static void dw_dma_disable(struct dw_dma *dw)
  78. {
  79. do_dw_dma_off(dw);
  80. }
  81. static void dw_dma_enable(struct dw_dma *dw)
  82. {
  83. do_dw_dma_on(dw);
  84. }
  85. int dw_dma_probe(struct dw_dma_chip *chip)
  86. {
  87. struct dw_dma *dw;
  88. dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL);
  89. if (!dw)
  90. return -ENOMEM;
  91. /* Channel operations */
  92. dw->initialize_chan = dw_dma_initialize_chan;
  93. dw->suspend_chan = dw_dma_suspend_chan;
  94. dw->resume_chan = dw_dma_resume_chan;
  95. dw->prepare_ctllo = dw_dma_prepare_ctllo;
  96. dw->encode_maxburst = dw_dma_encode_maxburst;
  97. dw->bytes2block = dw_dma_bytes2block;
  98. dw->block2bytes = dw_dma_block2bytes;
  99. /* Device operations */
  100. dw->set_device_name = dw_dma_set_device_name;
  101. dw->disable = dw_dma_disable;
  102. dw->enable = dw_dma_enable;
  103. chip->dw = dw;
  104. return do_dma_probe(chip);
  105. }
  106. EXPORT_SYMBOL_GPL(dw_dma_probe);
  107. int dw_dma_remove(struct dw_dma_chip *chip)
  108. {
  109. return do_dma_remove(chip);
  110. }
  111. EXPORT_SYMBOL_GPL(dw_dma_remove);