xref: /openbmc/linux/arch/mips/lantiq/xway/dcdc.c (revision 9cfc5c90)
1 /*
2  *  This program is free software; you can redistribute it and/or modify it
3  *  under the terms of the GNU General Public License version 2 as published
4  *  by the Free Software Foundation.
5  *
6  *  Copyright (C) 2012 John Crispin <blogic@openwrt.org>
7  *  Copyright (C) 2010 Sameer Ahmad, Lantiq GmbH
8  */
9 
10 #include <linux/ioport.h>
11 #include <linux/of_platform.h>
12 
13 #include <lantiq_soc.h>
14 
15 /* Bias and regulator Setup Register */
16 #define DCDC_BIAS_VREG0	0xa
17 /* Bias and regulator Setup Register */
18 #define DCDC_BIAS_VREG1	0xb
19 
20 #define dcdc_w8(x, y)	ltq_w8((x), dcdc_membase + (y))
21 #define dcdc_r8(x)	ltq_r8(dcdc_membase + (x))
22 
23 static void __iomem *dcdc_membase;
24 
25 static int dcdc_probe(struct platform_device *pdev)
26 {
27 	struct resource *res;
28 
29 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
30 	dcdc_membase = devm_ioremap_resource(&pdev->dev, res);
31 	if (IS_ERR(dcdc_membase))
32 		return PTR_ERR(dcdc_membase);
33 
34 	dev_info(&pdev->dev, "Core Voltage : %d mV\n",
35 		dcdc_r8(DCDC_BIAS_VREG1) * 8);
36 
37 	return 0;
38 }
39 
40 static const struct of_device_id dcdc_match[] = {
41 	{ .compatible = "lantiq,dcdc-xrx200" },
42 	{},
43 };
44 
45 static struct platform_driver dcdc_driver = {
46 	.probe = dcdc_probe,
47 	.driver = {
48 		.name = "dcdc-xrx200",
49 		.of_match_table = dcdc_match,
50 	},
51 };
52 
53 int __init dcdc_init(void)
54 {
55 	int ret = platform_driver_register(&dcdc_driver);
56 
57 	if (ret)
58 		pr_info("dcdc: Error registering platform driver\n");
59 	return ret;
60 }
61 
62 arch_initcall(dcdc_init);
63