/*
   * OMAP3517/3505-specific clock framework functions
   *
   * Copyright (C) 2010 Texas Instruments, Inc.

   * Copyright (C) 2011 Nokia Corporation

   *
   * Ranjith Lohithakshan
   * Paul Walmsley
   *
   * Parts of this code are based on code written by
   * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu,
   * Russell King
   *
   * 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.
   */
  #undef DEBUG
  
  #include <linux/kernel.h>
  #include <linux/clk.h>
  #include <linux/io.h>
  
  #include <plat/clock.h>
  
  #include "clock.h"
  #include "clock3517.h"

  #include "cm2xxx_3xxx.h"

  #include "cm-regbits-34xx.h"
  
  /*
   * In AM35xx IPSS, the {ICK,FCK} enable bits for modules are exported
   * in the same register at a bit offset of 0x8. The EN_ACK for ICK is
   * at an offset of 4 from ICK enable bit.
   */
  #define AM35XX_IPSS_ICK_MASK			0xF
  #define AM35XX_IPSS_ICK_EN_ACK_OFFSET 		0x4
  #define AM35XX_IPSS_ICK_FCK_OFFSET		0x8
  #define AM35XX_IPSS_CLK_IDLEST_VAL		0
  
  /**
   * am35xx_clk_find_idlest - return clock ACK info for AM35XX IPSS
   * @clk: struct clk * being enabled
   * @idlest_reg: void __iomem ** to store CM_IDLEST reg address into
   * @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into
   * @idlest_val: pointer to a u8 to store the CM_IDLEST indicator
   *
   * The interface clocks on AM35xx IPSS reflects the clock idle status
   * in the enable register itsel at a bit offset of 4 from the enable
   * bit. A value of 1 indicates that clock is enabled.
   */
  static void am35xx_clk_find_idlest(struct clk *clk,
  					    void __iomem **idlest_reg,
  					    u8 *idlest_bit,
  					    u8 *idlest_val)
  {
  	*idlest_reg = (__force void __iomem *)(clk->enable_reg);
  	*idlest_bit = clk->enable_bit + AM35XX_IPSS_ICK_EN_ACK_OFFSET;
  	*idlest_val = AM35XX_IPSS_CLK_IDLEST_VAL;
  }
  
  /**
   * am35xx_clk_find_companion - find companion clock to @clk
   * @clk: struct clk * to find the companion clock of
   * @other_reg: void __iomem ** to return the companion clock CM_*CLKEN va in
   * @other_bit: u8 ** to return the companion clock bit shift in
   *
   * Some clocks don't have companion clocks.  For example, modules with
   * only an interface clock (such as HECC) don't have a companion
   * clock.  Right now, this code relies on the hardware exporting a bit
   * in the correct companion register that indicates that the
   * nonexistent 'companion clock' is active.  Future patches will
   * associate this type of code with per-module data structures to
   * avoid this issue, and remove the casts.  No return value.
   */
  static void am35xx_clk_find_companion(struct clk *clk, void __iomem **other_reg,
  					    u8 *other_bit)
  {
  	*other_reg = (__force void __iomem *)(clk->enable_reg);
  	if (clk->enable_bit & AM35XX_IPSS_ICK_MASK)
  		*other_bit = clk->enable_bit + AM35XX_IPSS_ICK_FCK_OFFSET;
  	else
  		*other_bit = clk->enable_bit - AM35XX_IPSS_ICK_FCK_OFFSET;
  }
  
  const struct clkops clkops_am35xx_ipss_module_wait = {
  	.enable		= omap2_dflt_clk_enable,
  	.disable	= omap2_dflt_clk_disable,
  	.find_idlest	= am35xx_clk_find_idlest,
  	.find_companion	= am35xx_clk_find_companion,
  };
  
  /**
   * am35xx_clk_ipss_find_idlest - return CM_IDLEST info for IPSS
   * @clk: struct clk * being enabled
   * @idlest_reg: void __iomem ** to store CM_IDLEST reg address into
   * @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into
   * @idlest_val: pointer to a u8 to store the CM_IDLEST indicator
   *
   * The IPSS target CM_IDLEST bit is at a different shift from the
   * CM_{I,F}CLKEN bit.  Pass back the correct info via @idlest_reg
   * and @idlest_bit.  No return value.
   */
  static void am35xx_clk_ipss_find_idlest(struct clk *clk,
  					    void __iomem **idlest_reg,
  					    u8 *idlest_bit,
  					    u8 *idlest_val)
  {
  	u32 r;
  
  	r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20);
  	*idlest_reg = (__force void __iomem *)r;
  	*idlest_bit = AM35XX_ST_IPSS_SHIFT;
  	*idlest_val = OMAP34XX_CM_IDLEST_VAL;
  }
  
  const struct clkops clkops_am35xx_ipss_wait = {
  	.enable		= omap2_dflt_clk_enable,
  	.disable	= omap2_dflt_clk_disable,
  	.find_idlest	= am35xx_clk_ipss_find_idlest,
  	.find_companion	= omap2_clk_dflt_find_companion,

  	.allow_idle	= omap2_clkt_iclk_allow_idle,
  	.deny_idle	= omap2_clkt_iclk_deny_idle,

  };