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
pl353_smc_suspend(struct device * dev)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
pl353_smc_resume(struct device * dev)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
pl353_smc_probe(struct amba_device * adev,const struct amba_id * id)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
pl353_smc_remove(struct amba_device * adev)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
