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 #include <dm/device_compat.h>
  11 #include <linux/bitops.h>
  12 #include <linux/err.h>
  13
  14 #define UFS_SS_CTRL             0x4
  15 #define UFS_SS_RST_N_PCS        BIT(0)
  16 #define UFS_SS_CLK_26MHZ        BIT(4)
  17
  18 static int ti_j721e_ufs_probe(struct udevice *dev)
  19 {
  20         void __iomem *base;
  21         unsigned int clock;
  22         struct clk clk;
  23         u32 reg = 0;
  24         int ret;
  25
  26         ret = clk_get_by_index(dev, 0, &clk);
  27         if (ret) {
  28                 dev_err(dev, "failed to get M-PHY clock\n");
  29                 return ret;
  30         }
  31
  32         clock = clk_get_rate(&clk);
  33         if (IS_ERR_VALUE(clock)) {
  34                 dev_err(dev, "failed to get rate\n");
  35                 return ret;
  36         }
  37
  38         base = dev_remap_addr_index(dev, 0);
  39
  40         if (clock == 26000000)
  41                 reg |= UFS_SS_CLK_26MHZ;
  42         /* Take UFS slave device out of reset */
  43         reg |= UFS_SS_RST_N_PCS;
  44         writel(reg, base + UFS_SS_CTRL);
  45
  46         return 0;
  47 }
  48
  49 static int ti_j721e_ufs_remove(struct udevice *dev)
  50 {
  51         void __iomem *base = dev_remap_addr_index(dev, 0);
  52         u32 reg = readl(base + UFS_SS_CTRL);
  53
  54         reg &= ~UFS_SS_RST_N_PCS;
  55         writel(reg, base + UFS_SS_CTRL);
  56
  57         return 0;
  58 }
  59
  60 static const struct udevice_id ti_j721e_ufs_ids[] = {
  61         {
  62                 .compatible = "ti,j721e-ufs",
  63         },
  64         {},
  65 };
  66
  67 U_BOOT_DRIVER(ti_j721e_ufs) = {
  68         .name                   = "ti-j721e-ufs",
  69         .id                     = UCLASS_MISC,
  70         .of_match               = ti_j721e_ufs_ids,
  71         .probe                  = ti_j721e_ufs_probe,
  72         .remove                 = ti_j721e_ufs_remove,
  73         .flags                  = DM_FLAG_OS_PREPARE,
  74 };