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/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);