drivers/ufs/ti-j721e-ufs.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
   4  */
   5
   6 #include <asm/io.h>
   7 #include <clk.h>
   8 #include <common.h>
   9 #include <dm.h>
  10
  11 #define UFS_SS_CTRL             0x4
  12 #define UFS_SS_RST_N_PCS        BIT(0)
  13 #define UFS_SS_CLK_26MHZ        BIT(4)
  14
  15 static int ti_j721e_ufs_probe(struct udevice *dev)
  16 {
  17         void __iomem *base;
  18         unsigned int clock;
  19         struct clk clk;
  20         u32 reg = 0;
  21         int ret;
  22
  23         ret = clk_get_by_index(dev, 0, &clk);
  24         if (ret) {
  25                 dev_err(dev, "failed to get M-PHY clock\n");
  26                 return ret;
  27         }
  28
  29         clock = clk_get_rate(&clk);
  30         if (IS_ERR_VALUE(clock)) {
  31                 dev_err(dev, "failed to get rate\n");
  32                 return ret;
  33         }
  34
  35         base = dev_remap_addr_index(dev, 0);
  36
  37         if (clock == 26000000)
  38                 reg |= UFS_SS_CLK_26MHZ;
  39         /* Take UFS slave device out of reset */
  40         reg |= UFS_SS_RST_N_PCS;
  41         writel(reg, base + UFS_SS_CTRL);
  42
  43         return 0;
  44 }
  45
  46 static int ti_j721e_ufs_remove(struct udevice *dev)
  47 {
  48         void __iomem *base = dev_remap_addr_index(dev, 0);
  49         u32 reg = readl(base + UFS_SS_CTRL);
  50
  51         reg &= ~UFS_SS_RST_N_PCS;
  52         writel(reg, base + UFS_SS_CTRL);
  53
  54         return 0;
  55 }
  56
  57 static const struct udevice_id ti_j721e_ufs_ids[] = {
  58         {
  59                 .compatible = "ti,j721e-ufs",
  60         },
  61         {},
  62 };
  63
  64 U_BOOT_DRIVER(ti_j721e_ufs) = {
  65         .name                   = "ti-j721e-ufs",
  66         .id                     = UCLASS_MISC,
  67         .of_match               = ti_j721e_ufs_ids,
  68         .probe                  = ti_j721e_ufs_probe,
  69         .remove                 = ti_j721e_ufs_remove,
  70         .flags                  = DM_FLAG_OS_PREPARE,
  71 };