panel-samsung-s6e63m0-spi.c 2.1 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101
  1. // SPDX-License-Identifier: GPL-2.0
  2. #include <linux/device.h>
  3. #include <linux/module.h>
  4. #include <linux/spi/spi.h>
  5. #include <linux/delay.h>
  6. #include <drm/drm_print.h>
  7. #include "panel-samsung-s6e63m0.h"
  8. #define DATA_MASK 0x100
  9. static int s6e63m0_spi_dcs_read(struct device *dev, const u8 cmd, u8 *data)
  10. {
  11. /*
  12. * FIXME: implement reading DCS commands over SPI so we can
  13. * properly identify which physical panel is connected.
  14. */
  15. *data = 0;
  16. return 0;
  17. }
  18. static int s6e63m0_spi_write_word(struct device *dev, u16 data)
  19. {
  20. struct spi_device *spi = to_spi_device(dev);
  21. struct spi_transfer xfer = {
  22. .len = 2,
  23. .tx_buf = &data,
  24. };
  25. struct spi_message msg;
  26. spi_message_init(&msg);
  27. spi_message_add_tail(&xfer, &msg);
  28. return spi_sync(spi, &msg);
  29. }
  30. static int s6e63m0_spi_dcs_write(struct device *dev, const u8 *data, size_t len)
  31. {
  32. int ret = 0;
  33. dev_dbg(dev, "SPI writing dcs seq: %*ph\n", (int)len, data);
  34. ret = s6e63m0_spi_write_word(dev, *data);
  35. while (!ret && --len) {
  36. ++data;
  37. ret = s6e63m0_spi_write_word(dev, *data | DATA_MASK);
  38. }
  39. if (ret) {
  40. dev_err(dev, "SPI error %d writing dcs seq: %*ph\n", ret,
  41. (int)len, data);
  42. }
  43. usleep_range(300, 310);
  44. return ret;
  45. }
  46. static int s6e63m0_spi_probe(struct spi_device *spi)
  47. {
  48. struct device *dev = &spi->dev;
  49. int ret;
  50. spi->bits_per_word = 9;
  51. spi->mode = SPI_MODE_3;
  52. ret = spi_setup(spi);
  53. if (ret < 0) {
  54. dev_err(dev, "spi setup failed.\n");
  55. return ret;
  56. }
  57. return s6e63m0_probe(dev, s6e63m0_spi_dcs_read, s6e63m0_spi_dcs_write,
  58. false);
  59. }
  60. static int s6e63m0_spi_remove(struct spi_device *spi)
  61. {
  62. return s6e63m0_remove(&spi->dev);
  63. }
  64. static const struct of_device_id s6e63m0_spi_of_match[] = {
  65. { .compatible = "samsung,s6e63m0" },
  66. { /* sentinel */ }
  67. };
  68. MODULE_DEVICE_TABLE(of, s6e63m0_spi_of_match);
  69. static struct spi_driver s6e63m0_spi_driver = {
  70. .probe = s6e63m0_spi_probe,
  71. .remove = s6e63m0_spi_remove,
  72. .driver = {
  73. .name = "panel-samsung-s6e63m0",
  74. .of_match_table = s6e63m0_spi_of_match,
  75. },
  76. };
  77. module_spi_driver(s6e63m0_spi_driver);
  78. MODULE_AUTHOR("Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>");
  79. MODULE_DESCRIPTION("s6e63m0 LCD SPI Driver");
  80. MODULE_LICENSE("GPL v2");