target/linux/oxnas/files/drivers/reset/reset-ox820.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License as published by
   4  * the Free Software Foundation; either version 2 of the License, or
   5  * (at your option) any later version.
   6  */
   7
   8 #include <linux/err.h>
   9 #include <linux/io.h>
  10 #include <linux/module.h>
  11 #include <linux/of.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/reset-controller.h>
  14 #include <linux/slab.h>
  15 #include <linux/types.h>
  16 #include <mach/hardware.h>
  17
  18 static int ox820_reset_reset(struct reset_controller_dev *rcdev,
  19                               unsigned long id)
  20 {
  21         writel(BIT(id), SYS_CTRL_RST_SET_CTRL);
  22         writel(BIT(id), SYS_CTRL_RST_CLR_CTRL);
  23         return 0;
  24 }
  25
  26 static int ox820_reset_assert(struct reset_controller_dev *rcdev,
  27                               unsigned long id)
  28 {
  29         writel(BIT(id), SYS_CTRL_RST_SET_CTRL);
  30
  31         return 0;
  32 }
  33
  34 static int ox820_reset_deassert(struct reset_controller_dev *rcdev,
  35                                 unsigned long id)
  36 {
  37         writel(BIT(id), SYS_CTRL_RST_CLR_CTRL);
  38
  39         return 0;
  40 }
  41
  42 static struct reset_control_ops ox820_reset_ops = {
  43         .reset          = ox820_reset_reset,
  44         .assert         = ox820_reset_assert,
  45         .deassert       = ox820_reset_deassert,
  46 };
  47
  48 static const struct of_device_id ox820_reset_dt_ids[] = {
  49          { .compatible = "plxtech,nas782x-reset", },
  50          { /* sentinel */ },
  51 };
  52 MODULE_DEVICE_TABLE(of, ox820_reset_dt_ids);
  53
  54 struct reset_controller_dev rcdev;
  55
  56 static int ox820_reset_probe(struct platform_device *pdev)
  57 {
  58         struct reset_controller_dev *rcdev;
  59
  60         rcdev = devm_kzalloc(&pdev->dev, sizeof(*rcdev), GFP_KERNEL);
  61         if (!rcdev)
  62                 return -ENOMEM;
  63
  64         /* note: reset controller is statically mapped */
  65
  66         rcdev->owner = THIS_MODULE;
  67         rcdev->nr_resets = 32;
  68         rcdev->ops = &ox820_reset_ops;
  69         rcdev->of_node = pdev->dev.of_node;
  70         reset_controller_register(rcdev);
  71         platform_set_drvdata(pdev, rcdev);
  72
  73         return 0;
  74 }
  75
  76 static int ox820_reset_remove(struct platform_device *pdev)
  77 {
  78         struct reset_controller_dev *rcdev = platform_get_drvdata(pdev);
  79
  80         reset_controller_unregister(rcdev);
  81
  82         return 0;
  83 }
  84
  85 static struct platform_driver ox820_reset_driver = {
  86         .probe  = ox820_reset_probe,
  87         .remove = ox820_reset_remove,
  88         .driver = {
  89                 .name           = "ox820-reset",
  90                 .owner          = THIS_MODULE,
  91                 .of_match_table = ox820_reset_dt_ids,
  92         },
  93 };
  94
  95 static int __init ox820_reset_init(void)
  96 {
  97         return platform_driver_probe(&ox820_reset_driver,
  98                                      ox820_reset_probe);
  99 }
 100 /*
 101  * reset controller does not support probe deferral, so it has to be
 102  * initialized before any user, in particular, PCIE uses subsys_initcall.
 103  */
 104 arch_initcall(ox820_reset_init);
 105
 106 MODULE_AUTHOR("Ma Haijun");
 107 MODULE_LICENSE("GPL");