arch/arm/mach-s3c2410/s3c2440-dsc.c

   1 /* linux/arch/arm/mach-s3c2410/s3c2440-dsc.c
   2  *
   3  * Copyright (c) 2004-2005 Simtec Electronics
   4  *   Ben Dooks <ben@simtec.co.uk>
   5  *
   6  * Samsung S3C2440 Drive Strength Control support
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * Modifications:
  13  *     29-Aug-2004 BJD  Start of drive-strength control
  14  *     09-Nov-2004 BJD  Added symbol export
  15  *     11-Jan-2005 BJD  Include fix
  16 */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/types.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/init.h>
  22 #include <linux/module.h>
  23
  24 #include <asm/mach/arch.h>
  25 #include <asm/mach/map.h>
  26 #include <asm/mach/irq.h>
  27
  28 #include <asm/hardware.h>
  29 #include <asm/io.h>
  30 #include <asm/irq.h>
  31
  32 #include <asm/arch/regs-gpio.h>
  33 #include <asm/arch/regs-dsc.h>
  34
  35 #include "cpu.h"
  36 #include "s3c2440.h"
  37
  38 int s3c2440_set_dsc(unsigned int pin, unsigned int value)
  39 {
  40         void __iomem *base;
  41         unsigned long val;
  42         unsigned long flags;
  43         unsigned long mask;
  44
  45         base = (pin & S3C2440_SELECT_DSC1) ? S3C2440_DSC1 : S3C2440_DSC0;
  46         mask = 3 << S3C2440_DSC_GETSHIFT(pin);
  47
  48         local_irq_save(flags);
  49
  50         val = __raw_readl(base);
  51         val &= ~mask;
  52         val |= value & mask;
  53         __raw_writel(val, base);
  54
  55         local_irq_restore(flags);
  56         return 0;
  57 }
  58
  59 EXPORT_SYMBOL(s3c2440_set_dsc);