drivers/mmc/mmc-pwrseq.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2021 SAMSUNG Electronics
   4  * Jaehoon Chung <jh80.chung@samsung.com>
   5  */
   6
   7 #include <common.h>
   8 #include <dm.h>
   9 #include <mmc.h>
  10 #include <pwrseq.h>
  11 #include <asm/gpio.h>
  12 #include <linux/delay.h>
  13
  14 int mmc_pwrseq_get_power(struct udevice *dev, struct mmc_config *cfg)
  15 {
  16         /* Enable power if needed */
  17         return uclass_get_device_by_phandle(UCLASS_PWRSEQ, dev, "mmc-pwrseq",
  18                                            &cfg->pwr_dev);
  19 }
  20
  21 static int mmc_pwrseq_set_power(struct udevice *dev, bool enable)
  22 {
  23         struct gpio_desc reset;
  24         int ret;
  25
  26         ret = gpio_request_by_name(dev, "reset-gpios", 0, &reset, GPIOD_IS_OUT);
  27         if (ret)
  28                 return ret;
  29         dm_gpio_set_value(&reset, 1);
  30         udelay(1);
  31         dm_gpio_set_value(&reset, 0);
  32         udelay(200);
  33
  34         return 0;
  35 }
  36
  37 static const struct pwrseq_ops mmc_pwrseq_ops = {
  38         .set_power      = mmc_pwrseq_set_power,
  39 };
  40
  41 static const struct udevice_id mmc_pwrseq_ids[] = {
  42         { .compatible = "mmc-pwrseq-emmc" },
  43         { }
  44 };
  45
  46 U_BOOT_DRIVER(mmc_pwrseq_drv) = {
  47         .name           = "mmc_pwrseq_emmc",
  48         .id             = UCLASS_PWRSEQ,
  49         .of_match       = mmc_pwrseq_ids,
  50         .ops            = &mmc_pwrseq_ops,
  51 };