drivers/memory/pl353-smc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * ARM PL353 SMC driver
   4  *
   5  * Copyright (C) 2012 - 2018 Xilinx, Inc
   6  * Author: Punnaiah Choudary Kalluri <punnaiah@xilinx.com>
   7  * Author: Naga Sureshkumar Relli <nagasure@xilinx.com>
   8  */
   9
  10 #include <linux/clk.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/of_platform.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/amba/bus.h>
  16
  17 /**
  18  * struct pl353_smc_data - Private smc driver structure
  19  * @memclk:             Pointer to the peripheral clock
  20  * @aclk:               Pointer to the AXI peripheral clock
  21  */
  22 struct pl353_smc_data {
  23         struct clk              *memclk;
  24         struct clk              *aclk;
  25 };
  26
  27 static int __maybe_unused pl353_smc_suspend(struct device *dev)
  28 {
  29         struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev);
  30
  31         clk_disable(pl353_smc->memclk);
  32         clk_disable(pl353_smc->aclk);
  33
  34         return 0;
  35 }
  36
  37 static int __maybe_unused pl353_smc_resume(struct device *dev)
  38 {
  39         struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev);
  40         int ret;
  41
  42         ret = clk_enable(pl353_smc->aclk);
  43         if (ret) {
  44                 dev_err(dev, "Cannot enable axi domain clock.\n");
  45                 return ret;
  46         }
  47
  48         ret = clk_enable(pl353_smc->memclk);
  49         if (ret) {
  50                 dev_err(dev, "Cannot enable memory clock.\n");
  51                 clk_disable(pl353_smc->aclk);
  52                 return ret;
  53         }
  54
  55         return ret;
  56 }
  57
  58 static SIMPLE_DEV_PM_OPS(pl353_smc_dev_pm_ops, pl353_smc_suspend,
  59                          pl353_smc_resume);
  60
  61 static const struct of_device_id pl353_smc_supported_children[] = {
  62         {
  63                 .compatible = "cfi-flash"
  64         },
  65         {
  66                 .compatible = "arm,pl353-nand-r2p1",
  67         },
  68         {}
  69 };
  70
  71 static int pl353_smc_probe(struct amba_device *adev, const struct amba_id *id)
  72 {
  73         struct device_node *of_node = adev->dev.of_node;
  74         const struct of_device_id *match = NULL;
  75         struct pl353_smc_data *pl353_smc;
  76         struct device_node *child;
  77         int err;
  78
  79         pl353_smc = devm_kzalloc(&adev->dev, sizeof(*pl353_smc), GFP_KERNEL);
  80         if (!pl353_smc)
  81                 return -ENOMEM;
  82
  83         pl353_smc->aclk = devm_clk_get(&adev->dev, "apb_pclk");
  84         if (IS_ERR(pl353_smc->aclk)) {
  85                 dev_err(&adev->dev, "aclk clock not found.\n");
  86                 return PTR_ERR(pl353_smc->aclk);
  87         }
  88
  89         pl353_smc->memclk = devm_clk_get(&adev->dev, "memclk");
  90         if (IS_ERR(pl353_smc->memclk)) {
  91                 dev_err(&adev->dev, "memclk clock not found.\n");
  92                 return PTR_ERR(pl353_smc->memclk);
  93         }
  94
  95         err = clk_prepare_enable(pl353_smc->aclk);
  96         if (err) {
  97                 dev_err(&adev->dev, "Unable to enable AXI clock.\n");
  98                 return err;
  99         }
 100
 101         err = clk_prepare_enable(pl353_smc->memclk);
 102         if (err) {
 103                 dev_err(&adev->dev, "Unable to enable memory clock.\n");
 104                 goto disable_axi_clk;
 105         }
 106
 107         amba_set_drvdata(adev, pl353_smc);
 108
 109         /* Find compatible children. Only a single child is supported */
 110         for_each_available_child_of_node(of_node, child) {
 111                 match = of_match_node(pl353_smc_supported_children, child);
 112                 if (!match) {
 113                         dev_warn(&adev->dev, "unsupported child node\n");
 114                         continue;
 115                 }
 116                 break;
 117         }
 118         if (!match) {
 119                 err = -ENODEV;
 120                 dev_err(&adev->dev, "no matching children\n");
 121                 goto disable_mem_clk;
 122         }
 123
 124         of_platform_device_create(child, NULL, &adev->dev);
 125         of_node_put(child);
 126
 127         return 0;
 128
 129 disable_mem_clk:
 130         clk_disable_unprepare(pl353_smc->memclk);
 131 disable_axi_clk:
 132         clk_disable_unprepare(pl353_smc->aclk);
 133
 134         return err;
 135 }
 136
 137 static void pl353_smc_remove(struct amba_device *adev)
 138 {
 139         struct pl353_smc_data *pl353_smc = amba_get_drvdata(adev);
 140
 141         clk_disable_unprepare(pl353_smc->memclk);
 142         clk_disable_unprepare(pl353_smc->aclk);
 143 }
 144
 145 static const struct amba_id pl353_ids[] = {
 146         {
 147                 .id = 0x00041353,
 148                 .mask = 0x000fffff,
 149         },
 150         { 0, 0 },
 151 };
 152 MODULE_DEVICE_TABLE(amba, pl353_ids);
 153
 154 static struct amba_driver pl353_smc_driver = {
 155         .drv = {
 156                 .owner = THIS_MODULE,
 157                 .name = "pl353-smc",
 158                 .pm = &pl353_smc_dev_pm_ops,
 159         },
 160         .id_table = pl353_ids,
 161         .probe = pl353_smc_probe,
 162         .remove = pl353_smc_remove,
 163 };
 164
 165 module_amba_driver(pl353_smc_driver);
 166
 167 MODULE_AUTHOR("Xilinx, Inc.");
 168 MODULE_DESCRIPTION("ARM PL353 SMC Driver");
 169 MODULE_LICENSE("GPL");