drivers/reset/hisilicon/hi6220_reset.c

   1 /*
   2  * Hisilicon Hi6220 reset controller driver
   3  *
   4  * Copyright (c) 2015 Hisilicon Limited.
   5  *
   6  * Author: Feng Chen <puck.chen@hisilicon.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/io.h>
  14 #include <linux/init.h>
  15 #include <linux/module.h>
  16 #include <linux/bitops.h>
  17 #include <linux/of.h>
  18 #include <linux/reset-controller.h>
  19 #include <linux/reset.h>
  20 #include <linux/platform_device.h>
  21
  22 #define ASSERT_OFFSET            0x300
  23 #define DEASSERT_OFFSET          0x304
  24 #define MAX_INDEX                0x509
  25
  26 #define to_reset_data(x) container_of(x, struct hi6220_reset_data, rc_dev)
  27
  28 struct hi6220_reset_data {
  29         void __iomem                    *assert_base;
  30         void __iomem                    *deassert_base;
  31         struct reset_controller_dev     rc_dev;
  32 };
  33
  34 static int hi6220_reset_assert(struct reset_controller_dev *rc_dev,
  35                                unsigned long idx)
  36 {
  37         struct hi6220_reset_data *data = to_reset_data(rc_dev);
  38
  39         int bank = idx >> 8;
  40         int offset = idx & 0xff;
  41
  42         writel(BIT(offset), data->assert_base + (bank * 0x10));
  43
  44         return 0;
  45 }
  46
  47 static int hi6220_reset_deassert(struct reset_controller_dev *rc_dev,
  48                                  unsigned long idx)
  49 {
  50         struct hi6220_reset_data *data = to_reset_data(rc_dev);
  51
  52         int bank = idx >> 8;
  53         int offset = idx & 0xff;
  54
  55         writel(BIT(offset), data->deassert_base + (bank * 0x10));
  56
  57         return 0;
  58 }
  59
  60 static const struct reset_control_ops hi6220_reset_ops = {
  61         .assert = hi6220_reset_assert,
  62         .deassert = hi6220_reset_deassert,
  63 };
  64
  65 static int hi6220_reset_probe(struct platform_device *pdev)
  66 {
  67         struct hi6220_reset_data *data;
  68         struct resource *res;
  69         void __iomem *src_base;
  70
  71         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
  72         if (!data)
  73                 return -ENOMEM;
  74
  75         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  76         src_base = devm_ioremap_resource(&pdev->dev, res);
  77         if (IS_ERR(src_base))
  78                 return PTR_ERR(src_base);
  79
  80         data->assert_base = src_base + ASSERT_OFFSET;
  81         data->deassert_base = src_base + DEASSERT_OFFSET;
  82         data->rc_dev.nr_resets = MAX_INDEX;
  83         data->rc_dev.ops = &hi6220_reset_ops;
  84         data->rc_dev.of_node = pdev->dev.of_node;
  85
  86         return reset_controller_register(&data->rc_dev);
  87 }
  88
  89 static const struct of_device_id hi6220_reset_match[] = {
  90         { .compatible = "hisilicon,hi6220-sysctrl" },
  91         { },
  92 };
  93
  94 static struct platform_driver hi6220_reset_driver = {
  95         .probe = hi6220_reset_probe,
  96         .driver = {
  97                 .name = "reset-hi6220",
  98                 .of_match_table = hi6220_reset_match,
  99         },
 100 };
 101
 102 static int __init hi6220_reset_init(void)
 103 {
 104         return platform_driver_register(&hi6220_reset_driver);
 105 }
 106
 107 postcore_initcall(hi6220_reset_init);