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kernel/linux-rt-4.4.41/drivers/clk/imx/clk-fixup-mux.c 2.62 KB
5113f6f70   김현기   kernel add
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  /*
   * Copyright (C) 2013 Freescale Semiconductor, Inc.
   *
   * The code contained herein is licensed under the GNU General Public
   * License. You may obtain a copy of the GNU General Public License
   * Version 2 or later at the following locations:
   *
   * http://www.opensource.org/licenses/gpl-license.html
   * http://www.gnu.org/copyleft/gpl.html
   */
  
  #include <linux/clk-provider.h>
  #include <linux/err.h>
  #include <linux/io.h>
  #include <linux/slab.h>
  #include "clk.h"
  
  #define to_clk_mux(_hw) container_of(_hw, struct clk_mux, hw)
  
  /**
   * struct clk_fixup_mux - imx integer fixup multiplexer clock
   * @mux: the parent class
   * @ops: pointer to clk_ops of parent class
   * @fixup: a hook to fixup the write value
   *
   * The imx fixup multiplexer clock is a subclass of basic clk_mux
   * with an addtional fixup hook.
   */
  struct clk_fixup_mux {
  	struct clk_mux mux;
  	const struct clk_ops *ops;
  	void (*fixup)(u32 *val);
  };
  
  static inline struct clk_fixup_mux *to_clk_fixup_mux(struct clk_hw *hw)
  {
  	struct clk_mux *mux = to_clk_mux(hw);
  
  	return container_of(mux, struct clk_fixup_mux, mux);
  }
  
  static u8 clk_fixup_mux_get_parent(struct clk_hw *hw)
  {
  	struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
  
  	return fixup_mux->ops->get_parent(&fixup_mux->mux.hw);
  }
  
  static int clk_fixup_mux_set_parent(struct clk_hw *hw, u8 index)
  {
  	struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
  	struct clk_mux *mux = to_clk_mux(hw);
  	unsigned long flags = 0;
  	u32 val;
  
  	spin_lock_irqsave(mux->lock, flags);
  
  	val = readl(mux->reg);
  	val &= ~(mux->mask << mux->shift);
  	val |= index << mux->shift;
  	fixup_mux->fixup(&val);
  	writel(val, mux->reg);
  
  	spin_unlock_irqrestore(mux->lock, flags);
  
  	return 0;
  }
  
  static const struct clk_ops clk_fixup_mux_ops = {
  	.get_parent = clk_fixup_mux_get_parent,
  	.set_parent = clk_fixup_mux_set_parent,
  };
  
  struct clk *imx_clk_fixup_mux(const char *name, void __iomem *reg,
  			      u8 shift, u8 width, const char **parents,
  			      int num_parents, void (*fixup)(u32 *val))
  {
  	struct clk_fixup_mux *fixup_mux;
  	struct clk *clk;
  	struct clk_init_data init;
  
  	if (!fixup)
  		return ERR_PTR(-EINVAL);
  
  	fixup_mux = kzalloc(sizeof(*fixup_mux), GFP_KERNEL);
  	if (!fixup_mux)
  		return ERR_PTR(-ENOMEM);
  
  	init.name = name;
  	init.ops = &clk_fixup_mux_ops;
  	init.parent_names = parents;
  	init.num_parents = num_parents;
  	init.flags = 0;
  
  	fixup_mux->mux.reg = reg;
  	fixup_mux->mux.shift = shift;
  	fixup_mux->mux.mask = BIT(width) - 1;
  	fixup_mux->mux.lock = &imx_ccm_lock;
  	fixup_mux->mux.hw.init = &init;
  	fixup_mux->ops = &clk_mux_ops;
  	fixup_mux->fixup = fixup;
  
  	clk = clk_register(NULL, &fixup_mux->mux.hw);
  	if (IS_ERR(clk))
  		kfree(fixup_mux);
  
  	return clk;
  }