LXR linux/drivers/reset/reset-axs10x.c

   1/*
   2 * Copyright (C) 2017 Synopsys.
   3 *
   4 * Synopsys AXS10x reset driver.
   5 *
   6 * This file is licensed under the terms of the GNU General Public
   7 * License version 2. This program is licensed "as is" without any
   8 * warranty of any kind, whether express or implied.
   9 */
  10
  11#include <linux/io.h>
  12#include <linux/module.h>
  13#include <linux/mod_devicetable.h>
  14#include <linux/platform_device.h>
  15#include <linux/reset-controller.h>
  16
  17#define to_axs10x_rst(p)        container_of((p), struct axs10x_rst, rcdev)
  18
  19#define AXS10X_MAX_RESETS       32
  20
  21struct axs10x_rst {
  22        void __iomem                    *regs_rst;
  23        spinlock_t                      lock;
  24        struct reset_controller_dev     rcdev;
  25};
  26
  27static int axs10x_reset_reset(struct reset_controller_dev *rcdev,
  28                              unsigned long id)
  29{
  30        struct axs10x_rst *rst = to_axs10x_rst(rcdev);
  31        unsigned long flags;
  32
  33        spin_lock_irqsave(&rst->lock, flags);
  34        writel(BIT(id), rst->regs_rst);
  35        spin_unlock_irqrestore(&rst->lock, flags);
  36
  37        return 0;
  38}
  39
  40static const struct reset_control_ops axs10x_reset_ops = {
  41        .reset  = axs10x_reset_reset,
  42};
  43
  44static int axs10x_reset_probe(struct platform_device *pdev)
  45{
  46        struct axs10x_rst *rst;
  47        struct resource *mem;
  48
  49        rst = devm_kzalloc(&pdev->dev, sizeof(*rst), GFP_KERNEL);
  50        if (!rst)
  51                return -ENOMEM;
  52
  53        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  54        rst->regs_rst = devm_ioremap_resource(&pdev->dev, mem);
  55        if (IS_ERR(rst->regs_rst))
  56                return PTR_ERR(rst->regs_rst);
  57
  58        spin_lock_init(&rst->lock);
  59
  60        rst->rcdev.owner = THIS_MODULE;
  61        rst->rcdev.ops = &axs10x_reset_ops;
  62        rst->rcdev.of_node = pdev->dev.of_node;
  63        rst->rcdev.nr_resets = AXS10X_MAX_RESETS;
  64
  65        return devm_reset_controller_register(&pdev->dev, &rst->rcdev);
  66}
  67
  68static const struct of_device_id axs10x_reset_dt_match[] = {
  69        { .compatible = "snps,axs10x-reset" },
  70        { },
  71};
  72
  73static struct platform_driver axs10x_reset_driver = {
  74        .probe  = axs10x_reset_probe,
  75        .driver = {
  76                .name = "axs10x-reset",
  77                .of_match_table = axs10x_reset_dt_match,
  78        },
  79};
  80builtin_platform_driver(axs10x_reset_driver);
  81
  82MODULE_AUTHOR("Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>");
  83MODULE_DESCRIPTION("Synopsys AXS10x reset driver");
  84MODULE_LICENSE("GPL v2");
  85