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kernel/linux-rt-4.4.41/drivers/clk/imx/clk-gate-exclusive.c 2.33 KB
5113f6f70   김현기   kernel add
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  /*
   * Copyright 2014 Freescale Semiconductor, 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.
   */
  
  #include <linux/clk-provider.h>
  #include <linux/err.h>
  #include <linux/io.h>
  #include <linux/slab.h>
  #include "clk.h"
  
  /**
   * struct clk_gate_exclusive - i.MX specific gate clock which is mutually
   * exclusive with other gate clocks
   *
   * @gate: the parent class
   * @exclusive_mask: mask of gate bits which are mutually exclusive to this
   *	gate clock
   *
   * The imx exclusive gate clock is a subclass of basic clk_gate
   * with an addtional mask to indicate which other gate bits in the same
   * register is mutually exclusive to this gate clock.
   */
  struct clk_gate_exclusive {
  	struct clk_gate gate;
  	u32 exclusive_mask;
  };
  
  static int clk_gate_exclusive_enable(struct clk_hw *hw)
  {
  	struct clk_gate *gate = container_of(hw, struct clk_gate, hw);
  	struct clk_gate_exclusive *exgate = container_of(gate,
  					struct clk_gate_exclusive, gate);
  	u32 val = readl(gate->reg);
  
  	if (val & exgate->exclusive_mask)
  		return -EBUSY;
  
  	return clk_gate_ops.enable(hw);
  }
  
  static void clk_gate_exclusive_disable(struct clk_hw *hw)
  {
  	clk_gate_ops.disable(hw);
  }
  
  static int clk_gate_exclusive_is_enabled(struct clk_hw *hw)
  {
  	return clk_gate_ops.is_enabled(hw);
  }
  
  static const struct clk_ops clk_gate_exclusive_ops = {
  	.enable = clk_gate_exclusive_enable,
  	.disable = clk_gate_exclusive_disable,
  	.is_enabled = clk_gate_exclusive_is_enabled,
  };
  
  struct clk *imx_clk_gate_exclusive(const char *name, const char *parent,
  	 void __iomem *reg, u8 shift, u32 exclusive_mask)
  {
  	struct clk_gate_exclusive *exgate;
  	struct clk_gate *gate;
  	struct clk *clk;
  	struct clk_init_data init;
  
  	if (exclusive_mask == 0)
  		return ERR_PTR(-EINVAL);
  
  	exgate = kzalloc(sizeof(*exgate), GFP_KERNEL);
  	if (!exgate)
  		return ERR_PTR(-ENOMEM);
  	gate = &exgate->gate;
  
  	init.name = name;
  	init.ops = &clk_gate_exclusive_ops;
  	init.flags = CLK_SET_RATE_PARENT;
  	init.parent_names = parent ? &parent : NULL;
  	init.num_parents = parent ? 1 : 0;
  
  	gate->reg = reg;
  	gate->bit_idx = shift;
  	gate->lock = &imx_ccm_lock;
  	gate->hw.init = &init;
  	exgate->exclusive_mask = exclusive_mask;
  
  	clk = clk_register(NULL, &gate->hw);
  	if (IS_ERR(clk))
  		kfree(exgate);
  
  	return clk;
  }