xref: /openbmc/linux/arch/mips/lantiq/xway/dcdc.c (revision 046b212a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  *  Copyright (C) 2012 John Crispin <john@phrozen.org>
5  *  Copyright (C) 2010 Sameer Ahmad, Lantiq GmbH
6  */
7 
8 #include <linux/ioport.h>
9 #include <linux/mod_devicetable.h>
10 #include <linux/platform_device.h>
11 
12 #include <lantiq_soc.h>
13 
14 /* Bias and regulator Setup Register */
15 #define DCDC_BIAS_VREG0	0xa
16 /* Bias and regulator Setup Register */
17 #define DCDC_BIAS_VREG1	0xb
18 
19 #define dcdc_w8(x, y)	ltq_w8((x), dcdc_membase + (y))
20 #define dcdc_r8(x)	ltq_r8(dcdc_membase + (x))
21 
22 static void __iomem *dcdc_membase;
23 
24 static int dcdc_probe(struct platform_device *pdev)
25 {
26 	dcdc_membase = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
27 	if (IS_ERR(dcdc_membase))
28 		return PTR_ERR(dcdc_membase);
29 
30 	dev_info(&pdev->dev, "Core Voltage : %d mV\n",
31 		dcdc_r8(DCDC_BIAS_VREG1) * 8);
32 
33 	return 0;
34 }
35 
36 static const struct of_device_id dcdc_match[] = {
37 	{ .compatible = "lantiq,dcdc-xrx200" },
38 	{},
39 };
40 
41 static struct platform_driver dcdc_driver = {
42 	.probe = dcdc_probe,
43 	.driver = {
44 		.name = "dcdc-xrx200",
45 		.of_match_table = dcdc_match,
46 	},
47 };
48 
49 int __init dcdc_init(void)
50 {
51 	int ret = platform_driver_register(&dcdc_driver);
52 
53 	if (ret)
54 		pr_info("dcdc: Error registering platform driver\n");
55 	return ret;
56 }
57 
58 arch_initcall(dcdc_init);
59