xref: /openbmc/linux/drivers/clk/clk-fsl-flexspi.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Layerscape FlexSPI clock driver
4  *
5  * Copyright 2020 Michael Walle <michael@walle.cc>
6  */
7 
8 #include <linux/clk-provider.h>
9 #include <linux/io.h>
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 
13 static const struct clk_div_table ls1028a_flexspi_divs[] = {
14 	{ .val = 0, .div = 1, },
15 	{ .val = 1, .div = 2, },
16 	{ .val = 2, .div = 3, },
17 	{ .val = 3, .div = 4, },
18 	{ .val = 4, .div = 5, },
19 	{ .val = 5, .div = 6, },
20 	{ .val = 6, .div = 7, },
21 	{ .val = 7, .div = 8, },
22 	{ .val = 11, .div = 12, },
23 	{ .val = 15, .div = 16, },
24 	{ .val = 16, .div = 20, },
25 	{ .val = 17, .div = 24, },
26 	{ .val = 18, .div = 28, },
27 	{ .val = 19, .div = 32, },
28 	{ .val = 20, .div = 80, },
29 	{}
30 };
31 
32 static const struct clk_div_table lx2160a_flexspi_divs[] = {
33 	{ .val = 1, .div = 2, },
34 	{ .val = 3, .div = 4, },
35 	{ .val = 5, .div = 6, },
36 	{ .val = 7, .div = 8, },
37 	{ .val = 11, .div = 12, },
38 	{ .val = 15, .div = 16, },
39 	{ .val = 16, .div = 20, },
40 	{ .val = 17, .div = 24, },
41 	{ .val = 18, .div = 28, },
42 	{ .val = 19, .div = 32, },
43 	{ .val = 20, .div = 80, },
44 	{}
45 };
46 
47 static int fsl_flexspi_clk_probe(struct platform_device *pdev)
48 {
49 	struct device *dev = &pdev->dev;
50 	struct device_node *np = dev->of_node;
51 	const char *clk_name = np->name;
52 	const char *clk_parent;
53 	struct resource *res;
54 	void __iomem *reg;
55 	struct clk_hw *hw;
56 	const struct clk_div_table *divs;
57 
58 	divs = device_get_match_data(dev);
59 	if (!divs)
60 		return -ENOENT;
61 
62 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
63 	if (!res)
64 		return -ENOENT;
65 
66 	/*
67 	 * Can't use devm_ioremap_resource() or devm_of_iomap() because the
68 	 * resource might already be taken by the parent device.
69 	 */
70 	reg = devm_ioremap(dev, res->start, resource_size(res));
71 	if (!reg)
72 		return -ENOMEM;
73 
74 	clk_parent = of_clk_get_parent_name(np, 0);
75 	if (!clk_parent)
76 		return -EINVAL;
77 
78 	of_property_read_string(np, "clock-output-names", &clk_name);
79 
80 	hw = devm_clk_hw_register_divider_table(dev, clk_name, clk_parent, 0,
81 						reg, 0, 5, 0, divs, NULL);
82 	if (IS_ERR(hw))
83 		return PTR_ERR(hw);
84 
85 	return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, hw);
86 }
87 
88 static const struct of_device_id fsl_flexspi_clk_dt_ids[] = {
89 	{ .compatible = "fsl,ls1028a-flexspi-clk", .data = &ls1028a_flexspi_divs },
90 	{ .compatible = "fsl,lx2160a-flexspi-clk", .data = &lx2160a_flexspi_divs },
91 	{}
92 };
93 MODULE_DEVICE_TABLE(of, fsl_flexspi_clk_dt_ids);
94 
95 static struct platform_driver fsl_flexspi_clk_driver = {
96 	.driver = {
97 		.name = "fsl-flexspi-clk",
98 		.of_match_table = fsl_flexspi_clk_dt_ids,
99 	},
100 	.probe = fsl_flexspi_clk_probe,
101 };
102 module_platform_driver(fsl_flexspi_clk_driver);
103 
104 MODULE_DESCRIPTION("FlexSPI clock driver for Layerscape SoCs");
105 MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
106 MODULE_LICENSE("GPL");
107