drivers/ufs/host/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 <linux/clk.h>
   7 #include <linux/io.h>
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/of_platform.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/pm_runtime.h>
  13
  14 #define TI_UFS_SS_CTRL          0x4
  15 #define TI_UFS_SS_RST_N_PCS     BIT(0)
  16 #define TI_UFS_SS_CLK_26MHZ     BIT(4)
  17
  18 static int ti_j721e_ufs_probe(struct platform_device *pdev)
  19 {
  20         struct device *dev = &pdev->dev;
  21         unsigned long clk_rate;
  22         void __iomem *regbase;
  23         struct clk *clk;
  24         u32 reg = 0;
  25         int ret;
  26
  27         regbase = devm_platform_ioremap_resource(pdev, 0);
  28         if (IS_ERR(regbase))
  29                 return PTR_ERR(regbase);
  30
  31         pm_runtime_enable(dev);
  32         ret = pm_runtime_resume_and_get(dev);
  33         if (ret < 0)
  34                 goto disable_pm;
  35
  36         /* Select MPHY refclk frequency */
  37         clk = devm_clk_get(dev, NULL);
  38         if (IS_ERR(clk)) {
  39                 ret = PTR_ERR(clk);
  40                 dev_err(dev, "Cannot claim MPHY clock.\n");
  41                 goto clk_err;
  42         }
  43         clk_rate = clk_get_rate(clk);
  44         if (clk_rate == 26000000)
  45                 reg |= TI_UFS_SS_CLK_26MHZ;
  46         devm_clk_put(dev, clk);
  47
  48         /*  Take UFS slave device out of reset */
  49         reg |= TI_UFS_SS_RST_N_PCS;
  50         writel(reg, regbase + TI_UFS_SS_CTRL);
  51
  52         ret = of_platform_populate(pdev->dev.of_node, NULL, NULL,
  53                                    dev);
  54         if (ret) {
  55                 dev_err(dev, "failed to populate child nodes %d\n", ret);
  56                 goto clk_err;
  57         }
  58
  59         return ret;
  60
  61 clk_err:
  62         pm_runtime_put_sync(dev);
  63 disable_pm:
  64         pm_runtime_disable(dev);
  65         return ret;
  66 }
  67
  68 static void ti_j721e_ufs_remove(struct platform_device *pdev)
  69 {
  70         of_platform_depopulate(&pdev->dev);
  71         pm_runtime_put_sync(&pdev->dev);
  72         pm_runtime_disable(&pdev->dev);
  73 }
  74
  75 static const struct of_device_id ti_j721e_ufs_of_match[] = {
  76         {
  77                 .compatible = "ti,j721e-ufs",
  78         },
  79         { },
  80 };
  81
  82 MODULE_DEVICE_TABLE(of, ti_j721e_ufs_of_match);
  83
  84 static struct platform_driver ti_j721e_ufs_driver = {
  85         .probe  = ti_j721e_ufs_probe,
  86         .remove = ti_j721e_ufs_remove,
  87         .driver = {
  88                 .name   = "ti-j721e-ufs",
  89                 .of_match_table = ti_j721e_ufs_of_match,
  90         },
  91 };
  92 module_platform_driver(ti_j721e_ufs_driver);
  93
  94 MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
  95 MODULE_DESCRIPTION("TI UFS host controller glue driver");
  96 MODULE_LICENSE("GPL v2");