drivers/ufs/ti-j721e-ufs.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com/
   4  */
   5
   6 #include <asm/io.h>
   7 #include <clk.h>
   8 #include <dm.h>
   9 #include <dm/device_compat.h>
  10 #include <linux/bitops.h>
  11 #include <linux/err.h>
  12
  13 #define UFS_SS_CTRL             0x4
  14 #define UFS_SS_RST_N_PCS        BIT(0)
  15 #define UFS_SS_CLK_26MHZ        BIT(4)
  16
  17 static int ti_j721e_ufs_probe(struct udevice *dev)
  18 {
  19         void __iomem *base;
  20         unsigned int clock;
  21         struct clk clk;
  22         u32 reg = 0;
  23         int ret;
  24
  25         ret = clk_get_by_index(dev, 0, &clk);
  26         if (ret) {
  27                 dev_err(dev, "failed to get M-PHY clock\n");
  28                 return ret;
  29         }
  30
  31         clock = clk_get_rate(&clk);
  32         if (IS_ERR_VALUE(clock)) {
  33                 dev_err(dev, "failed to get rate\n");
  34                 return ret;
  35         }
  36
  37         base = dev_remap_addr_index(dev, 0);
  38
  39         if (clock == 26000000)
  40                 reg |= UFS_SS_CLK_26MHZ;
  41         /* Take UFS slave device out of reset */
  42         reg |= UFS_SS_RST_N_PCS;
  43         writel(reg, base + UFS_SS_CTRL);
  44
  45         return 0;
  46 }
  47
  48 static int ti_j721e_ufs_remove(struct udevice *dev)
  49 {
  50         void __iomem *base = dev_remap_addr_index(dev, 0);
  51         u32 reg = readl(base + UFS_SS_CTRL);
  52
  53         reg &= ~UFS_SS_RST_N_PCS;
  54         writel(reg, base + UFS_SS_CTRL);
  55
  56         return 0;
  57 }
  58
  59 static const struct udevice_id ti_j721e_ufs_ids[] = {
  60         {
  61                 .compatible = "ti,j721e-ufs",
  62         },
  63         {},
  64 };
  65
  66 U_BOOT_DRIVER(ti_j721e_ufs) = {
  67         .name                   = "ti-j721e-ufs",
  68         .id                     = UCLASS_MISC,
  69         .of_match               = ti_j721e_ufs_ids,
  70         .probe                  = ti_j721e_ufs_probe,
  71         .remove                 = ti_j721e_ufs_remove,
  72         .flags                  = DM_FLAG_OS_PREPARE,
  73 };