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/module.h>
18 #include <linux/platform_device.h>
19 #include <dt-bindings/clock/bcm2835-aux.h>
20 
21 #define BCM2835_AUXIRQ		0x00
22 #define BCM2835_AUXENB		0x04
23 
24 static int bcm2835_aux_clk_probe(struct platform_device *pdev)
25 {
26 	struct device *dev = &pdev->dev;
27 	struct clk_hw_onecell_data *onecell;
28 	const char *parent;
29 	struct clk *parent_clk;
30 	struct resource *res;
31 	void __iomem *reg, *gate;
32 
33 	parent_clk = devm_clk_get(dev, NULL);
34 	if (IS_ERR(parent_clk))
35 		return PTR_ERR(parent_clk);
36 	parent = __clk_get_name(parent_clk);
37 
38 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
39 	reg = devm_ioremap_resource(dev, res);
40 	if (IS_ERR(reg))
41 		return PTR_ERR(reg);
42 
43 	onecell = devm_kmalloc(dev, sizeof(*onecell) + sizeof(*onecell->hws) *
44 			       BCM2835_AUX_CLOCK_COUNT, GFP_KERNEL);
45 	if (!onecell)
46 		return -ENOMEM;
47 	onecell->num = BCM2835_AUX_CLOCK_COUNT;
48 
49 	gate = reg + BCM2835_AUXENB;
50 	onecell->hws[BCM2835_AUX_CLOCK_UART] =
51 		clk_hw_register_gate(dev, "aux_uart", parent, 0, gate, 0, 0, NULL);
52 
53 	onecell->hws[BCM2835_AUX_CLOCK_SPI1] =
54 		clk_hw_register_gate(dev, "aux_spi1", parent, 0, gate, 1, 0, NULL);
55 
56 	onecell->hws[BCM2835_AUX_CLOCK_SPI2] =
57 		clk_hw_register_gate(dev, "aux_spi2", parent, 0, gate, 2, 0, NULL);
58 
59 	return of_clk_add_hw_provider(pdev->dev.of_node, of_clk_hw_onecell_get,
60 				      onecell);
61 }
62 
63 static const struct of_device_id bcm2835_aux_clk_of_match[] = {
64 	{ .compatible = "brcm,bcm2835-aux", },
65 	{},
66 };
67 MODULE_DEVICE_TABLE(of, bcm2835_aux_clk_of_match);
68 
69 static struct platform_driver bcm2835_aux_clk_driver = {
70 	.driver = {
71 		.name = "bcm2835-aux-clk",
72 		.of_match_table = bcm2835_aux_clk_of_match,
73 	},
74 	.probe          = bcm2835_aux_clk_probe,
75 };
76 builtin_platform_driver(bcm2835_aux_clk_driver);
77 
78 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
79 MODULE_DESCRIPTION("BCM2835 auxiliary peripheral clock driver");
80 MODULE_LICENSE("GPL v2");
81