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kernel/linux-imx6_3.14.28/arch/arm/mach-s3c24xx/clock-dclk.c 4.24 KB
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  /*
   * Copyright (c) 2004-2008 Simtec Electronics
   *	Ben Dooks <ben@simtec.co.uk>
   *	http://armlinux.simtec.co.uk/
   *
   * 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.
   *
   * S3C24XX - definitions for DCLK and CLKOUT registers
   */
  
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/clk.h>
  #include <linux/io.h>
  
  #include <mach/regs-clock.h>
  #include <mach/regs-gpio.h>
  
  #include <plat/clock.h>
  #include <plat/cpu.h>
  
  /* clocks that could be registered by external code */
  
  static int s3c24xx_dclk_enable(struct clk *clk, int enable)
  {
  	unsigned long dclkcon = __raw_readl(S3C24XX_DCLKCON);
  
  	if (enable)
  		dclkcon |= clk->ctrlbit;
  	else
  		dclkcon &= ~clk->ctrlbit;
  
  	__raw_writel(dclkcon, S3C24XX_DCLKCON);
  
  	return 0;
  }
  
  static int s3c24xx_dclk_setparent(struct clk *clk, struct clk *parent)
  {
  	unsigned long dclkcon;
  	unsigned int uclk;
  
  	if (parent == &clk_upll)
  		uclk = 1;
  	else if (parent == &clk_p)
  		uclk = 0;
  	else
  		return -EINVAL;
  
  	clk->parent = parent;
  
  	dclkcon = __raw_readl(S3C24XX_DCLKCON);
  
  	if (clk->ctrlbit == S3C2410_DCLKCON_DCLK0EN) {
  		if (uclk)
  			dclkcon |= S3C2410_DCLKCON_DCLK0_UCLK;
  		else
  			dclkcon &= ~S3C2410_DCLKCON_DCLK0_UCLK;
  	} else {
  		if (uclk)
  			dclkcon |= S3C2410_DCLKCON_DCLK1_UCLK;
  		else
  			dclkcon &= ~S3C2410_DCLKCON_DCLK1_UCLK;
  	}
  
  	__raw_writel(dclkcon, S3C24XX_DCLKCON);
  
  	return 0;
  }
  static unsigned long s3c24xx_calc_div(struct clk *clk, unsigned long rate)
  {
  	unsigned long div;
  
  	if ((rate == 0) || !clk->parent)
  		return 0;
  
  	div = clk_get_rate(clk->parent) / rate;
  	if (div < 2)
  		div = 2;
  	else if (div > 16)
  		div = 16;
  
  	return div;
  }
  
  static unsigned long s3c24xx_round_dclk_rate(struct clk *clk,
  	unsigned long rate)
  {
  	unsigned long div = s3c24xx_calc_div(clk, rate);
  
  	if (div == 0)
  		return 0;
  
  	return clk_get_rate(clk->parent) / div;
  }
  
  static int s3c24xx_set_dclk_rate(struct clk *clk, unsigned long rate)
  {
  	unsigned long mask, data, div = s3c24xx_calc_div(clk, rate);
  
  	if (div == 0)
  		return -EINVAL;
  
  	if (clk == &s3c24xx_dclk0) {
  		mask = S3C2410_DCLKCON_DCLK0_DIV_MASK |
  			S3C2410_DCLKCON_DCLK0_CMP_MASK;
  		data = S3C2410_DCLKCON_DCLK0_DIV(div) |
  			S3C2410_DCLKCON_DCLK0_CMP((div + 1) / 2);
  	} else if (clk == &s3c24xx_dclk1) {
  		mask = S3C2410_DCLKCON_DCLK1_DIV_MASK |
  			S3C2410_DCLKCON_DCLK1_CMP_MASK;
  		data = S3C2410_DCLKCON_DCLK1_DIV(div) |
  			S3C2410_DCLKCON_DCLK1_CMP((div + 1) / 2);
  	} else
  		return -EINVAL;
  
  	clk->rate = clk_get_rate(clk->parent) / div;
  	__raw_writel(((__raw_readl(S3C24XX_DCLKCON) & ~mask) | data),
  		S3C24XX_DCLKCON);
  	return clk->rate;
  }
  static int s3c24xx_clkout_setparent(struct clk *clk, struct clk *parent)
  {
  	unsigned long mask;
  	unsigned long source;
  
  	/* calculate the MISCCR setting for the clock */
  
  	if (parent == &clk_mpll)
  		source = S3C2410_MISCCR_CLK0_MPLL;
  	else if (parent == &clk_upll)
  		source = S3C2410_MISCCR_CLK0_UPLL;
  	else if (parent == &clk_f)
  		source = S3C2410_MISCCR_CLK0_FCLK;
  	else if (parent == &clk_h)
  		source = S3C2410_MISCCR_CLK0_HCLK;
  	else if (parent == &clk_p)
  		source = S3C2410_MISCCR_CLK0_PCLK;
  	else if (clk == &s3c24xx_clkout0 && parent == &s3c24xx_dclk0)
  		source = S3C2410_MISCCR_CLK0_DCLK0;
  	else if (clk == &s3c24xx_clkout1 && parent == &s3c24xx_dclk1)
  		source = S3C2410_MISCCR_CLK0_DCLK0;
  	else
  		return -EINVAL;
  
  	clk->parent = parent;
  
  	if (clk == &s3c24xx_clkout0)
  		mask = S3C2410_MISCCR_CLK0_MASK;
  	else {
  		source <<= 4;
  		mask = S3C2410_MISCCR_CLK1_MASK;
  	}
  
  	s3c2410_modify_misccr(mask, source);
  	return 0;
  }
  
  /* external clock definitions */
  
  static struct clk_ops dclk_ops = {
  	.set_parent	= s3c24xx_dclk_setparent,
  	.set_rate	= s3c24xx_set_dclk_rate,
  	.round_rate	= s3c24xx_round_dclk_rate,
  };
  
  struct clk s3c24xx_dclk0 = {
  	.name		= "dclk0",
  	.ctrlbit	= S3C2410_DCLKCON_DCLK0EN,
  	.enable	        = s3c24xx_dclk_enable,
  	.ops		= &dclk_ops,
  };
  
  struct clk s3c24xx_dclk1 = {
  	.name		= "dclk1",
  	.ctrlbit	= S3C2410_DCLKCON_DCLK1EN,
  	.enable		= s3c24xx_dclk_enable,
  	.ops		= &dclk_ops,
  };
  
  static struct clk_ops clkout_ops = {
  	.set_parent	= s3c24xx_clkout_setparent,
  };
  
  struct clk s3c24xx_clkout0 = {
  	.name		= "clkout0",
  	.ops		= &clkout_ops,
  };
  
  struct clk s3c24xx_clkout1 = {
  	.name		= "clkout1",
  	.ops		= &clkout_ops,
  };