phy-ulpi-viewport.c 1.6 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * Copyright (C) 2011 Google, Inc.
  4. */
  5. #include <linux/export.h>
  6. #include <linux/kernel.h>
  7. #include <linux/usb.h>
  8. #include <linux/io.h>
  9. #include <linux/iopoll.h>
  10. #include <linux/usb/otg.h>
  11. #include <linux/usb/ulpi.h>
  12. #define ULPI_VIEW_WAKEUP (1 << 31)
  13. #define ULPI_VIEW_RUN (1 << 30)
  14. #define ULPI_VIEW_WRITE (1 << 29)
  15. #define ULPI_VIEW_READ (0 << 29)
  16. #define ULPI_VIEW_ADDR(x) (((x) & 0xff) << 16)
  17. #define ULPI_VIEW_DATA_READ(x) (((x) >> 8) & 0xff)
  18. #define ULPI_VIEW_DATA_WRITE(x) ((x) & 0xff)
  19. static int ulpi_viewport_wait(void __iomem *view, u32 mask)
  20. {
  21. u32 val;
  22. return readl_poll_timeout_atomic(view, val, !(val & mask), 1, 2000);
  23. }
  24. static int ulpi_viewport_read(struct usb_phy *otg, u32 reg)
  25. {
  26. int ret;
  27. void __iomem *view = otg->io_priv;
  28. writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
  29. ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
  30. if (ret)
  31. return ret;
  32. writel(ULPI_VIEW_RUN | ULPI_VIEW_READ | ULPI_VIEW_ADDR(reg), view);
  33. ret = ulpi_viewport_wait(view, ULPI_VIEW_RUN);
  34. if (ret)
  35. return ret;
  36. return ULPI_VIEW_DATA_READ(readl(view));
  37. }
  38. static int ulpi_viewport_write(struct usb_phy *otg, u32 val, u32 reg)
  39. {
  40. int ret;
  41. void __iomem *view = otg->io_priv;
  42. writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
  43. ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
  44. if (ret)
  45. return ret;
  46. writel(ULPI_VIEW_RUN | ULPI_VIEW_WRITE | ULPI_VIEW_DATA_WRITE(val) |
  47. ULPI_VIEW_ADDR(reg), view);
  48. return ulpi_viewport_wait(view, ULPI_VIEW_RUN);
  49. }
  50. struct usb_phy_io_ops ulpi_viewport_access_ops = {
  51. .read = ulpi_viewport_read,
  52. .write = ulpi_viewport_write,
  53. };
  54. EXPORT_SYMBOL_GPL(ulpi_viewport_access_ops);