mmc-pwrseq.c 1.1 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051
  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * (C) Copyright 2021 SAMSUNG Electronics
  4. * Jaehoon Chung <jh80.chung@samsung.com>
  5. */
  6. #include <common.h>
  7. #include <dm.h>
  8. #include <mmc.h>
  9. #include <pwrseq.h>
  10. #include <asm/gpio.h>
  11. #include <linux/delay.h>
  12. int mmc_pwrseq_get_power(struct udevice *dev, struct mmc_config *cfg)
  13. {
  14. /* Enable power if needed */
  15. return uclass_get_device_by_phandle(UCLASS_PWRSEQ, dev, "mmc-pwrseq",
  16. &cfg->pwr_dev);
  17. }
  18. static int mmc_pwrseq_set_power(struct udevice *dev, bool enable)
  19. {
  20. struct gpio_desc reset;
  21. int ret;
  22. ret = gpio_request_by_name(dev, "reset-gpios", 0, &reset, GPIOD_IS_OUT);
  23. if (ret)
  24. return ret;
  25. dm_gpio_set_value(&reset, 1);
  26. udelay(1);
  27. dm_gpio_set_value(&reset, 0);
  28. udelay(200);
  29. return 0;
  30. }
  31. static const struct pwrseq_ops mmc_pwrseq_ops = {
  32. .set_power = mmc_pwrseq_set_power,
  33. };
  34. static const struct udevice_id mmc_pwrseq_ids[] = {
  35. { .compatible = "mmc-pwrseq-emmc" },
  36. { }
  37. };
  38. U_BOOT_DRIVER(mmc_pwrseq_drv) = {
  39. .name = "mmc_pwrseq_emmc",
  40. .id = UCLASS_PWRSEQ,
  41. .of_match = mmc_pwrseq_ids,
  42. .ops = &mmc_pwrseq_ops,
  43. };