drivers/scsi/ufs/cdns-pltfrm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Platform UFS Host driver for Cadence controller
   4  *
   5  * Copyright (C) 2018 Cadence Design Systems, Inc.
   6  *
   7  * Authors:
   8  *      Jan Kotas <jank@cadence.com>
   9  *
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/of.h>
  16 #include <linux/time.h>
  17
  18 #include "ufshcd-pltfrm.h"
  19
  20 #define CDNS_UFS_REG_HCLKDIV 0xFC
  21
  22 /**
  23  * Sets HCLKDIV register value based on the core_clk
  24  * @hba: host controller instance
  25  *
  26  * Return zero for success and non-zero for failure
  27  */
  28 static int cdns_ufs_set_hclkdiv(struct ufs_hba *hba)
  29 {
  30         struct ufs_clk_info *clki;
  31         struct list_head *head = &hba->clk_list_head;
  32         unsigned long core_clk_rate = 0;
  33         u32 core_clk_div = 0;
  34
  35         if (list_empty(head))
  36                 return 0;
  37
  38         list_for_each_entry(clki, head, list) {
  39                 if (IS_ERR_OR_NULL(clki->clk))
  40                         continue;
  41                 if (!strcmp(clki->name, "core_clk"))
  42                         core_clk_rate = clk_get_rate(clki->clk);
  43         }
  44
  45         if (!core_clk_rate) {
  46                 dev_err(hba->dev, "%s: unable to find core_clk rate\n",
  47                         __func__);
  48                 return -EINVAL;
  49         }
  50
  51         core_clk_div = core_clk_rate / USEC_PER_SEC;
  52
  53         ufshcd_writel(hba, core_clk_div, CDNS_UFS_REG_HCLKDIV);
  54         /**
  55          * Make sure the register was updated,
  56          * UniPro layer will not work with an incorrect value.
  57          */
  58         mb();
  59
  60         return 0;
  61 }
  62
  63 /**
  64  * Sets clocks used by the controller
  65  * @hba: host controller instance
  66  * @on: if true, enable clocks, otherwise disable
  67  * @status: notify stage (pre, post change)
  68  *
  69  * Return zero for success and non-zero for failure
  70  */
  71 static int cdns_ufs_setup_clocks(struct ufs_hba *hba, bool on,
  72                                  enum ufs_notify_change_status status)
  73 {
  74         if ((!on) || (status == PRE_CHANGE))
  75                 return 0;
  76
  77         return cdns_ufs_set_hclkdiv(hba);
  78 }
  79
  80 static struct ufs_hba_variant_ops cdns_pltfm_hba_vops = {
  81         .name = "cdns-ufs-pltfm",
  82         .setup_clocks = cdns_ufs_setup_clocks,
  83 };
  84
  85 /**
  86  * cdns_ufs_pltfrm_probe - probe routine of the driver
  87  * @pdev: pointer to platform device handle
  88  *
  89  * Return zero for success and non-zero for failure
  90  */
  91 static int cdns_ufs_pltfrm_probe(struct platform_device *pdev)
  92 {
  93         int err;
  94         struct device *dev = &pdev->dev;
  95
  96         /* Perform generic probe */
  97         err = ufshcd_pltfrm_init(pdev, &cdns_pltfm_hba_vops);
  98         if (err)
  99                 dev_err(dev, "ufshcd_pltfrm_init() failed %d\n", err);
 100
 101         return err;
 102 }
 103
 104 /**
 105  * cdns_ufs_pltfrm_remove - removes the ufs driver
 106  * @pdev: pointer to platform device handle
 107  *
 108  * Always returns 0
 109  */
 110 static int cdns_ufs_pltfrm_remove(struct platform_device *pdev)
 111 {
 112         struct ufs_hba *hba =  platform_get_drvdata(pdev);
 113
 114         ufshcd_remove(hba);
 115         return 0;
 116 }
 117
 118 static const struct of_device_id cdns_ufs_of_match[] = {
 119         { .compatible = "cdns,ufshc" },
 120         {},
 121 };
 122
 123 MODULE_DEVICE_TABLE(of, cdns_ufs_of_match);
 124
 125 static const struct dev_pm_ops cdns_ufs_dev_pm_ops = {
 126         .suspend         = ufshcd_pltfrm_suspend,
 127         .resume          = ufshcd_pltfrm_resume,
 128         .runtime_suspend = ufshcd_pltfrm_runtime_suspend,
 129         .runtime_resume  = ufshcd_pltfrm_runtime_resume,
 130         .runtime_idle    = ufshcd_pltfrm_runtime_idle,
 131 };
 132
 133 static struct platform_driver cdns_ufs_pltfrm_driver = {
 134         .probe  = cdns_ufs_pltfrm_probe,
 135         .remove = cdns_ufs_pltfrm_remove,
 136         .driver = {
 137                 .name   = "cdns-ufshcd",
 138                 .pm     = &cdns_ufs_dev_pm_ops,
 139                 .of_match_table = cdns_ufs_of_match,
 140         },
 141 };
 142
 143 module_platform_driver(cdns_ufs_pltfrm_driver);
 144
 145 MODULE_AUTHOR("Jan Kotas <jank@cadence.com>");
 146 MODULE_DESCRIPTION("Cadence UFS host controller platform driver");
 147 MODULE_LICENSE("GPL v2");
 148 MODULE_VERSION(UFSHCD_DRIVER_VERSION);