arch/arm/mach-s3c2440/dsc.c

   1 /* linux/arch/arm/mach-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
  13 #include <linux/kernel.h>
  14 #include <linux/types.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/io.h>
  19
  20 #include <asm/mach/arch.h>
  21 #include <asm/mach/map.h>
  22 #include <asm/mach/irq.h>
  23
  24 #include <mach/hardware.h>
  25 #include <asm/irq.h>
  26
  27 #include <mach/regs-gpio.h>
  28 #include <mach/regs-dsc.h>
  29
  30 #include <plat/cpu.h>
  31 #include <plat/s3c2440.h>
  32
  33 int s3c2440_set_dsc(unsigned int pin, unsigned int value)
  34 {
  35         void __iomem *base;
  36         unsigned long val;
  37         unsigned long flags;
  38         unsigned long mask;
  39
  40         base = (pin & S3C2440_SELECT_DSC1) ? S3C2440_DSC1 : S3C2440_DSC0;
  41         mask = 3 << S3C2440_DSC_GETSHIFT(pin);
  42
  43         local_irq_save(flags);
  44
  45         val = __raw_readl(base);
  46         val &= ~mask;
  47         val |= value & mask;
  48         __raw_writel(val, base);
  49
  50         local_irq_restore(flags);
  51         return 0;
  52 }
  53
  54 EXPORT_SYMBOL(s3c2440_set_dsc);