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"); 170