1 /*
2  * Copyright (C) 2015 Broadcom
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 
15 #include <linux/clk.h>
16 #include <linux/clk-provider.h>
17 #include <linux/clk/bcm2835.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <dt-bindings/clock/bcm2835-aux.h>
21 
22 #define BCM2835_AUXIRQ		0x00
23 #define BCM2835_AUXENB		0x04
24 
25 static int bcm2835_aux_clk_probe(struct platform_device *pdev)
26 {
27 	struct device *dev = &pdev->dev;
28 	struct clk_onecell_data *onecell;
29 	const char *parent;
30 	struct clk *parent_clk;
31 	struct resource *res;
32 	void __iomem *reg, *gate;
33 
34 	parent_clk = devm_clk_get(dev, NULL);
35 	if (IS_ERR(parent_clk))
36 		return PTR_ERR(parent_clk);
37 	parent = __clk_get_name(parent_clk);
38 
39 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
40 	reg = devm_ioremap_resource(dev, res);
41 	if (!reg)
42 		return -ENODEV;
43 
44 	onecell = devm_kmalloc(dev, sizeof(*onecell), GFP_KERNEL);
45 	if (!onecell)
46 		return -ENOMEM;
47 	onecell->clk_num = BCM2835_AUX_CLOCK_COUNT;
48 	onecell->clks = devm_kcalloc(dev, BCM2835_AUX_CLOCK_COUNT,
49 				     sizeof(*onecell->clks), GFP_KERNEL);
50 	if (!onecell->clks)
51 		return -ENOMEM;
52 
53 	gate = reg + BCM2835_AUXENB;
54 	onecell->clks[BCM2835_AUX_CLOCK_UART] =
55 		clk_register_gate(dev, "aux_uart", parent, 0, gate, 0, 0, NULL);
56 
57 	onecell->clks[BCM2835_AUX_CLOCK_SPI1] =
58 		clk_register_gate(dev, "aux_spi1", parent, 0, gate, 1, 0, NULL);
59 
60 	onecell->clks[BCM2835_AUX_CLOCK_SPI2] =
61 		clk_register_gate(dev, "aux_spi2", parent, 0, gate, 2, 0, NULL);
62 
63 	of_clk_add_provider(pdev->dev.of_node, of_clk_src_onecell_get, onecell);
64 
65 	return 0;
66 }
67 
68 static const struct of_device_id bcm2835_aux_clk_of_match[] = {
69 	{ .compatible = "brcm,bcm2835-aux", },
70 	{},
71 };
72 MODULE_DEVICE_TABLE(of, bcm2835_aux_clk_of_match);
73 
74 static struct platform_driver bcm2835_aux_clk_driver = {
75 	.driver = {
76 		.name = "bcm2835-aux-clk",
77 		.of_match_table = bcm2835_aux_clk_of_match,
78 	},
79 	.probe          = bcm2835_aux_clk_probe,
80 };
81 builtin_platform_driver(bcm2835_aux_clk_driver);
82 
83 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
84 MODULE_DESCRIPTION("BCM2835 auxiliary peripheral clock driver");
85 MODULE_LICENSE("GPL v2");
86