1 /*
2  * Copyright (C) 2017 Synopsys.
3  *
4  * Synopsys AXS10x reset driver.
5  *
6  * This file is licensed under the terms of the GNU General Public
7  * License version 2. This program is licensed "as is" without any
8  * warranty of any kind, whether express or implied.
9  */
10 
11 #include <linux/io.h>
12 #include <linux/module.h>
13 #include <linux/mod_devicetable.h>
14 #include <linux/platform_device.h>
15 #include <linux/reset-controller.h>
16 
17 #define to_axs10x_rst(p)	container_of((p), struct axs10x_rst, rcdev)
18 
19 #define AXS10X_MAX_RESETS	32
20 
21 struct axs10x_rst {
22 	void __iomem			*regs_rst;
23 	spinlock_t			lock;
24 	struct reset_controller_dev	rcdev;
25 };
26 
axs10x_reset_reset(struct reset_controller_dev * rcdev,unsigned long id)27 static int axs10x_reset_reset(struct reset_controller_dev *rcdev,
28 			      unsigned long id)
29 {
30 	struct axs10x_rst *rst = to_axs10x_rst(rcdev);
31 	unsigned long flags;
32 
33 	spin_lock_irqsave(&rst->lock, flags);
34 	writel(BIT(id), rst->regs_rst);
35 	spin_unlock_irqrestore(&rst->lock, flags);
36 
37 	return 0;
38 }
39 
40 static const struct reset_control_ops axs10x_reset_ops = {
41 	.reset	= axs10x_reset_reset,
42 };
43 
axs10x_reset_probe(struct platform_device * pdev)44 static int axs10x_reset_probe(struct platform_device *pdev)
45 {
46 	struct axs10x_rst *rst;
47 	struct resource *mem;
48 
49 	rst = devm_kzalloc(&pdev->dev, sizeof(*rst), GFP_KERNEL);
50 	if (!rst)
51 		return -ENOMEM;
52 
53 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
54 	rst->regs_rst = devm_ioremap_resource(&pdev->dev, mem);
55 	if (IS_ERR(rst->regs_rst))
56 		return PTR_ERR(rst->regs_rst);
57 
58 	spin_lock_init(&rst->lock);
59 
60 	rst->rcdev.owner = THIS_MODULE;
61 	rst->rcdev.ops = &axs10x_reset_ops;
62 	rst->rcdev.of_node = pdev->dev.of_node;
63 	rst->rcdev.nr_resets = AXS10X_MAX_RESETS;
64 
65 	return devm_reset_controller_register(&pdev->dev, &rst->rcdev);
66 }
67 
68 static const struct of_device_id axs10x_reset_dt_match[] = {
69 	{ .compatible = "snps,axs10x-reset" },
70 	{ },
71 };
72 
73 static struct platform_driver axs10x_reset_driver = {
74 	.probe	= axs10x_reset_probe,
75 	.driver	= {
76 		.name = "axs10x-reset",
77 		.of_match_table = axs10x_reset_dt_match,
78 	},
79 };
80 builtin_platform_driver(axs10x_reset_driver);
81 
82 MODULE_AUTHOR("Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>");
83 MODULE_DESCRIPTION("Synopsys AXS10x reset driver");
84 MODULE_LICENSE("GPL v2");
85