arch/mips/lantiq/xway/dcdc.c

   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/of_platform.h>
  10
  11 #include <lantiq_soc.h>
  12
  13 /* Bias and regulator Setup Register */
  14 #define DCDC_BIAS_VREG0 0xa
  15 /* Bias and regulator Setup Register */
  16 #define DCDC_BIAS_VREG1 0xb
  17
  18 #define dcdc_w8(x, y)   ltq_w8((x), dcdc_membase + (y))
  19 #define dcdc_r8(x)      ltq_r8(dcdc_membase + (x))
  20
  21 static void __iomem *dcdc_membase;
  22
  23 static int dcdc_probe(struct platform_device *pdev)
  24 {
  25         struct resource *res;
  26
  27         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  28         dcdc_membase = devm_ioremap_resource(&pdev->dev, res);
  29         if (IS_ERR(dcdc_membase))
  30                 return PTR_ERR(dcdc_membase);
  31
  32         dev_info(&pdev->dev, "Core Voltage : %d mV\n",
  33                 dcdc_r8(DCDC_BIAS_VREG1) * 8);
  34
  35         return 0;
  36 }
  37
  38 static const struct of_device_id dcdc_match[] = {
  39         { .compatible = "lantiq,dcdc-xrx200" },
  40         {},
  41 };
  42
  43 static struct platform_driver dcdc_driver = {
  44         .probe = dcdc_probe,
  45         .driver = {
  46                 .name = "dcdc-xrx200",
  47                 .of_match_table = dcdc_match,
  48         },
  49 };
  50
  51 int __init dcdc_init(void)
  52 {
  53         int ret = platform_driver_register(&dcdc_driver);
  54
  55         if (ret)
  56                 pr_info("dcdc: Error registering platform driver\n");
  57         return ret;
  58 }
  59
  60 arch_initcall(dcdc_init);