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kernel/linux-rt-4.4.41/arch/blackfin/mach-bf561/coreb.c 1.86 KB
5113f6f70   김현기   kernel add
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  /* Load firmware into Core B on a BF561
   *
   * Copyright 2004-2009 Analog Devices Inc.
   * Licensed under the GPL-2 or later.
   */
  
  /* The Core B reset func requires code in the application that is loaded into
   * Core B.  In order to reset, the application needs to install an interrupt
   * handler for Supplemental Interrupt 0, that sets RETI to 0xff600000 and
   * writes bit 11 of SICB_SYSCR when bit 5 of SICA_SYSCR is 0.  This causes Core
   * B to stall when Supplemental Interrupt 0 is set, and will reset PC to
   * 0xff600000 when COREB_SRAM_INIT is cleared.
   */
  
  #include <linux/device.h>
  #include <linux/fs.h>
  #include <linux/kernel.h>
  #include <linux/miscdevice.h>
  #include <linux/module.h>
  
  #define CMD_COREB_START		_IO('b', 0)
  #define CMD_COREB_STOP		_IO('b', 1)
  #define CMD_COREB_RESET		_IO('b', 2)
  
  static long
  coreb_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  {
  	int ret = 0;
  
  	switch (cmd) {
  	case CMD_COREB_START:
  		bfin_write_SYSCR(bfin_read_SYSCR() & ~0x0020);
  		break;
  	case CMD_COREB_STOP:
  		bfin_write_SYSCR(bfin_read_SYSCR() | 0x0020);
  		bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | 0x0080);
  		break;
  	case CMD_COREB_RESET:
  		bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | 0x0080);
  		break;
  	default:
  		ret = -EINVAL;
  		break;
  	}
  
  	CSYNC();
  
  	return ret;
  }
  
  static const struct file_operations coreb_fops = {
  	.owner          = THIS_MODULE,
  	.unlocked_ioctl = coreb_ioctl,
  	.llseek		= noop_llseek,
  };
  
  static struct miscdevice coreb_dev = {
  	.minor = MISC_DYNAMIC_MINOR,
  	.name  = "coreb",
  	.fops  = &coreb_fops,
  };
  
  static int __init bf561_coreb_init(void)
  {
  	return misc_register(&coreb_dev);
  }
  module_init(bf561_coreb_init);
  
  static void __exit bf561_coreb_exit(void)
  {
  	misc_deregister(&coreb_dev);
  }
  module_exit(bf561_coreb_exit);
  
  MODULE_AUTHOR("Bas Vermeulen <bvermeul@blackstar.xs4all.nl>");
  MODULE_DESCRIPTION("BF561 Core B Support");
  MODULE_LICENSE("GPL");