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.h> 14 #include <linux/of_platform.h> 15 #include <linux/platform_device.h> 16 #include <linux/amba/bus.h> 17 18 /** 19 * struct pl353_smc_data - Private smc driver structure 20 * @memclk: Pointer to the peripheral clock 21 * @aclk: Pointer to the AXI peripheral clock 22 */ 23 struct pl353_smc_data { 24 struct clk *memclk; 25 struct clk *aclk; 26 }; 27 28 static int __maybe_unused pl353_smc_suspend(struct device *dev) 29 { 30 struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev); 31 32 clk_disable(pl353_smc->memclk); 33 clk_disable(pl353_smc->aclk); 34 35 return 0; 36 } 37 38 static int __maybe_unused pl353_smc_resume(struct device *dev) 39 { 40 struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev); 41 int ret; 42 43 ret = clk_enable(pl353_smc->aclk); 44 if (ret) { 45 dev_err(dev, "Cannot enable axi domain clock.\n"); 46 return ret; 47 } 48 49 ret = clk_enable(pl353_smc->memclk); 50 if (ret) { 51 dev_err(dev, "Cannot enable memory clock.\n"); 52 clk_disable(pl353_smc->aclk); 53 return ret; 54 } 55 56 return ret; 57 } 58 59 static SIMPLE_DEV_PM_OPS(pl353_smc_dev_pm_ops, pl353_smc_suspend, 60 pl353_smc_resume); 61 62 static const struct of_device_id pl353_smc_supported_children[] = { 63 { 64 .compatible = "cfi-flash" 65 }, 66 { 67 .compatible = "arm,pl353-nand-r2p1", 68 }, 69 {} 70 }; 71 72 static int pl353_smc_probe(struct amba_device *adev, const struct amba_id *id) 73 { 74 struct device_node *of_node = adev->dev.of_node; 75 const struct of_device_id *match = NULL; 76 struct pl353_smc_data *pl353_smc; 77 struct device_node *child; 78 int err; 79 80 pl353_smc = devm_kzalloc(&adev->dev, sizeof(*pl353_smc), GFP_KERNEL); 81 if (!pl353_smc) 82 return -ENOMEM; 83 84 pl353_smc->aclk = devm_clk_get(&adev->dev, "apb_pclk"); 85 if (IS_ERR(pl353_smc->aclk)) { 86 dev_err(&adev->dev, "aclk clock not found.\n"); 87 return PTR_ERR(pl353_smc->aclk); 88 } 89 90 pl353_smc->memclk = devm_clk_get(&adev->dev, "memclk"); 91 if (IS_ERR(pl353_smc->memclk)) { 92 dev_err(&adev->dev, "memclk clock not found.\n"); 93 return PTR_ERR(pl353_smc->memclk); 94 } 95 96 err = clk_prepare_enable(pl353_smc->aclk); 97 if (err) { 98 dev_err(&adev->dev, "Unable to enable AXI clock.\n"); 99 return err; 100 } 101 102 err = clk_prepare_enable(pl353_smc->memclk); 103 if (err) { 104 dev_err(&adev->dev, "Unable to enable memory clock.\n"); 105 goto disable_axi_clk; 106 } 107 108 amba_set_drvdata(adev, pl353_smc); 109 110 /* Find compatible children. Only a single child is supported */ 111 for_each_available_child_of_node(of_node, child) { 112 match = of_match_node(pl353_smc_supported_children, child); 113 if (!match) { 114 dev_warn(&adev->dev, "unsupported child node\n"); 115 continue; 116 } 117 break; 118 } 119 if (!match) { 120 err = -ENODEV; 121 dev_err(&adev->dev, "no matching children\n"); 122 goto disable_mem_clk; 123 } 124 125 of_platform_device_create(child, NULL, &adev->dev); 126 of_node_put(child); 127 128 return 0; 129 130 disable_mem_clk: 131 clk_disable_unprepare(pl353_smc->memclk); 132 disable_axi_clk: 133 clk_disable_unprepare(pl353_smc->aclk); 134 135 return err; 136 } 137 138 static void pl353_smc_remove(struct amba_device *adev) 139 { 140 struct pl353_smc_data *pl353_smc = amba_get_drvdata(adev); 141 142 clk_disable_unprepare(pl353_smc->memclk); 143 clk_disable_unprepare(pl353_smc->aclk); 144 } 145 146 static const struct amba_id pl353_ids[] = { 147 { 148 .id = 0x00041353, 149 .mask = 0x000fffff, 150 }, 151 { 0, 0 }, 152 }; 153 MODULE_DEVICE_TABLE(amba, pl353_ids); 154 155 static struct amba_driver pl353_smc_driver = { 156 .drv = { 157 .owner = THIS_MODULE, 158 .name = "pl353-smc", 159 .pm = &pl353_smc_dev_pm_ops, 160 }, 161 .id_table = pl353_ids, 162 .probe = pl353_smc_probe, 163 .remove = pl353_smc_remove, 164 }; 165 166 module_amba_driver(pl353_smc_driver); 167 168 MODULE_AUTHOR("Xilinx, Inc."); 169 MODULE_DESCRIPTION("ARM PL353 SMC Driver"); 170 MODULE_LICENSE("GPL"); 171