text: /* linux/arch/arm/mach-s3c2440/clock.c
   *
   * Copyright (c) 2004-2005 Simtec Electronics
   *	http://armlinux.simtec.co.uk/
   *	Ben Dooks <ben@simtec.co.uk>
   *
   * S3C2440 Clock support
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
  
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/list.h>
  #include <linux/errno.h>
  #include <linux/err.h>
  #include <linux/device.h>
  #include <linux/sysdev.h>
  #include <linux/interrupt.h>
  #include <linux/ioport.h>
  #include <linux/mutex.h>
  #include <linux/clk.h>
  #include <linux/io.h>
  
  #include <mach/hardware.h>
  #include <asm/atomic.h>
  #include <asm/irq.h>
  
  #include <mach/regs-clock.h>
  
  #include <plat/clock.h>
  #include <plat/cpu.h>
  
  /* S3C2440 extended clock support */
  
  static unsigned long s3c2440_camif_upll_round(struct clk *clk,
  					      unsigned long rate)
  {
  	unsigned long parent_rate = clk_get_rate(clk->parent);
  	int div;
  
  	if (rate > parent_rate)
  		return parent_rate;
  
  	/* note, we remove the +/- 1 calculations for the divisor */
  
  	div = (parent_rate / rate) / 2;
  
  	if (div < 1)
  		div = 1;
  	else if (div > 16)
  		div = 16;
  
  	return parent_rate / (div * 2);
  }
  
  static int s3c2440_camif_upll_setrate(struct clk *clk, unsigned long rate)
  {
  	unsigned long parent_rate = clk_get_rate(clk->parent);
  	unsigned long camdivn =  __raw_readl(S3C2440_CAMDIVN);
  
  	rate = s3c2440_camif_upll_round(clk, rate);
  
  	camdivn &= ~(S3C2440_CAMDIVN_CAMCLK_SEL | S3C2440_CAMDIVN_CAMCLK_MASK);
  
  	if (rate != parent_rate) {
  		camdivn |= S3C2440_CAMDIVN_CAMCLK_SEL;
  		camdivn |= (((parent_rate / rate) / 2) - 1);
  	}
  
  	__raw_writel(camdivn, S3C2440_CAMDIVN);
  
  	return 0;
  }
  
  /* Extra S3C2440 clocks */
  
  static struct clk s3c2440_clk_cam = {
  	.name		= "camif",
  	.id		= -1,
  	.enable		= s3c2410_clkcon_enable,
  	.ctrlbit	= S3C2440_CLKCON_CAMERA,
  };
  
  static struct clk s3c2440_clk_cam_upll = {
  	.name		= "camif-upll",
  	.id		= -1,
  	.set_rate	= s3c2440_camif_upll_setrate,
  	.round_rate	= s3c2440_camif_upll_round,
  };
  
  static struct clk s3c2440_clk_ac97 = {
  	.name		= "ac97",
  	.id		= -1,
  	.enable		= s3c2410_clkcon_enable,
  	.ctrlbit	= S3C2440_CLKCON_CAMERA,
  };
  
  static int s3c2440_clk_add(struct sys_device *sysdev)
  {
  	struct clk *clock_upll;
  	struct clk *clock_h;
  	struct clk *clock_p;
  
  	clock_p = clk_get(NULL, "pclk");
  	clock_h = clk_get(NULL, "hclk");
  	clock_upll = clk_get(NULL, "upll");
  
  	if (IS_ERR(clock_p) || IS_ERR(clock_h) || IS_ERR(clock_upll)) {
  		printk(KERN_ERR "S3C2440: Failed to get parent clocks\n");
  		return -EINVAL;
  	}
  
  	s3c2440_clk_cam.parent = clock_h;
  	s3c2440_clk_ac97.parent = clock_p;
  	s3c2440_clk_cam_upll.parent = clock_upll;
  
  	s3c24xx_register_clock(&s3c2440_clk_ac97);
  	s3c24xx_register_clock(&s3c2440_clk_cam);
  	s3c24xx_register_clock(&s3c2440_clk_cam_upll);
  
  	clk_disable(&s3c2440_clk_ac97);
  	clk_disable(&s3c2440_clk_cam);
  
  	return 0;
  }
  
  static struct sysdev_driver s3c2440_clk_driver = {
  	.add	= s3c2440_clk_add,
  };
  
  static __init int s3c24xx_clk_driver(void)
  {
  	return sysdev_driver_register(&s3c2440_sysclass, &s3c2440_clk_driver);
  }
  
  arch_initcall(s3c24xx_clk_driver);
  