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kernel/linux-rt-4.4.41/drivers/clk/mediatek/reset.c 2.33 KB
5113f6f70   김현기   kernel add
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  /*
   * Copyright (c) 2014 MediaTek Inc.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   */
  
  #include <linux/mfd/syscon.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/platform_device.h>
  #include <linux/regmap.h>
  #include <linux/reset-controller.h>
  #include <linux/slab.h>
  
  #include "clk-mtk.h"
  
  struct mtk_reset {
  	struct regmap *regmap;
  	int regofs;
  	struct reset_controller_dev rcdev;
  };
  
  static int mtk_reset_assert(struct reset_controller_dev *rcdev,
  			      unsigned long id)
  {
  	struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
  
  	return regmap_update_bits(data->regmap, data->regofs + ((id / 32) << 2),
  			BIT(id % 32), ~0);
  }
  
  static int mtk_reset_deassert(struct reset_controller_dev *rcdev,
  				unsigned long id)
  {
  	struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
  
  	return regmap_update_bits(data->regmap, data->regofs + ((id / 32) << 2),
  			BIT(id % 32), 0);
  }
  
  static int mtk_reset(struct reset_controller_dev *rcdev,
  			      unsigned long id)
  {
  	int ret;
  
  	ret = mtk_reset_assert(rcdev, id);
  	if (ret)
  		return ret;
  
  	return mtk_reset_deassert(rcdev, id);
  }
  
  static struct reset_control_ops mtk_reset_ops = {
  	.assert = mtk_reset_assert,
  	.deassert = mtk_reset_deassert,
  	.reset = mtk_reset,
  };
  
  void mtk_register_reset_controller(struct device_node *np,
  			unsigned int num_regs, int regofs)
  {
  	struct mtk_reset *data;
  	int ret;
  	struct regmap *regmap;
  
  	regmap = syscon_node_to_regmap(np);
  	if (IS_ERR(regmap)) {
  		pr_err("Cannot find regmap for %s: %ld
  ", np->full_name,
  				PTR_ERR(regmap));
  		return;
  	}
  
  	data = kzalloc(sizeof(*data), GFP_KERNEL);
  	if (!data)
  		return;
  
  	data->regmap = regmap;
  	data->regofs = regofs;
  	data->rcdev.owner = THIS_MODULE;
  	data->rcdev.nr_resets = num_regs * 32;
  	data->rcdev.ops = &mtk_reset_ops;
  	data->rcdev.of_node = np;
  
  	ret = reset_controller_register(&data->rcdev);
  	if (ret) {
  		pr_err("could not register reset controller: %d
  ", ret);
  		kfree(data);
  		return;
  	}
  }