target/linux/lantiq/patches-3.8/0031-MIPS-lantiq-adds-minimal-dcdc-driver.patch

   1 From 1f95983593d5b6634c13ead8f923237484dc611e Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Wed, 5 Dec 2012 17:38:48 +0100
   4 Subject: [PATCH 31/40] MIPS: lantiq: adds minimal dcdc driver
   5
   6 This driver so far only reads the core voltage.
   7
   8 Signed-off-by: John Crispin <blogic@openwrt.org>
   9 ---
  10  arch/mips/lantiq/xway/Makefile |    2 +-
  11  arch/mips/lantiq/xway/dcdc.c   |   74 ++++++++++++++++++++++++++++++++++++++++
  12  2 files changed, 75 insertions(+), 1 deletion(-)
  13  create mode 100644 arch/mips/lantiq/xway/dcdc.c
  14
  15 --- a/arch/mips/lantiq/xway/Makefile
  16 +++ b/arch/mips/lantiq/xway/Makefile
  17 @@ -1,3 +1,3 @@
  18 -obj-y := prom.o sysctrl.o clk.o reset.o dma.o gptu.o
  19 +obj-y := prom.o sysctrl.o clk.o reset.o dma.o gptu.o dcdc.o
  20
  21  obj-$(CONFIG_XRX200_PHY_FW) += xrx200_phy_fw.o
  22 --- /dev/null
  23 +++ b/arch/mips/lantiq/xway/dcdc.c
  24 @@ -0,0 +1,74 @@
  25 +/*
  26 + *  This program is free software; you can redistribute it and/or modify it
  27 + *  under the terms of the GNU General Public License version 2 as published
  28 + *  by the Free Software Foundation.
  29 + *
  30 + *  Copyright (C) 2012 John Crispin <blogic@openwrt.org>
  31 + *  Copyright (C) 2010 Sameer Ahmad, Lantiq GmbH
  32 + */
  33 +
  34 +#include <linux/interrupt.h>
  35 +#include <linux/ioport.h>
  36 +#include <linux/module.h>
  37 +#include <linux/of_platform.h>
  38 +#include <linux/of_irq.h>
  39 +
  40 +#include <lantiq_soc.h>
  41 +
  42 +/* Bias and regulator Setup Register */
  43 +#define DCDC_BIAS_VREG0        0xa
  44 +/* Bias and regulator Setup Register */
  45 +#define DCDC_BIAS_VREG1        0xb
  46 +
  47 +#define dcdc_w8(x, y)  ltq_w8((x), dcdc_membase + (y))
  48 +#define dcdc_r8(x)     ltq_r8(dcdc_membase + (x))
  49 +
  50 +static void __iomem *dcdc_membase;
  51 +
  52 +static int dcdc_probe(struct platform_device *pdev)
  53 +{
  54 +       struct resource *res;
  55 +
  56 +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  57 +       if (!res) {
  58 +               dev_err(&pdev->dev, "Failed to get resource\n");
  59 +               return -ENOMEM;
  60 +       }
  61 +
  62 +       /* remap dcdc register range */
  63 +       dcdc_membase = devm_request_and_ioremap(&pdev->dev, res);
  64 +       if (!dcdc_membase) {
  65 +               dev_err(&pdev->dev, "Failed to remap resource\n");
  66 +               return -ENOMEM;
  67 +       }
  68 +
  69 +       dev_info(&pdev->dev, "Core Voltage : %d mV\n", dcdc_r8(DCDC_BIAS_VREG1) * 8);
  70 +
  71 +       return 0;
  72 +}
  73 +
  74 +static const struct of_device_id dcdc_match[] = {
  75 +       { .compatible = "lantiq,dcdc-xrx200" },
  76 +       {},
  77 +};
  78 +MODULE_DEVICE_TABLE(of, dcdc_match);
  79 +
  80 +static struct platform_driver dcdc_driver = {
  81 +       .probe = dcdc_probe,
  82 +       .driver = {
  83 +               .name = "dcdc-xrx200",
  84 +               .owner = THIS_MODULE,
  85 +               .of_match_table = dcdc_match,
  86 +       },
  87 +};
  88 +
  89 +int __init dcdc_init(void)
  90 +{
  91 +       int ret = platform_driver_register(&dcdc_driver);
  92 +
  93 +       if (ret)
  94 +               pr_info("dcdc: Error registering platform driver\n");
  95 +       return ret;
  96 +}
  97 +
  98 +arch_initcall(dcdc_init);