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kernel/linux-rt-4.4.41/arch/arm/mach-imx/cpu-imx5.c 2.4 KB
5113f6f70   김현기   kernel add
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  /*
   * Copyright 2008-2010 Freescale Semiconductor, Inc. All Rights Reserved.
   *
   * The code contained herein is licensed under the GNU General Public
   * License. You may obtain a copy of the GNU General Public License
   * Version 2 or later at the following locations:
   *
   * http://www.opensource.org/licenses/gpl-license.html
   * http://www.gnu.org/copyleft/gpl.html
   *
   * This file contains the CPU initialization code.
   */
  
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/io.h>
  #include <linux/of.h>
  #include <linux/of_address.h>
  
  #include "hardware.h"
  #include "common.h"
  
  static int mx5_cpu_rev = -1;
  
  #define IIM_SREV 0x24
  
  static u32 imx5_read_srev_reg(const char *compat)
  {
  	void __iomem *iim_base;
  	struct device_node *np;
  	u32 srev;
  
  	np = of_find_compatible_node(NULL, NULL, compat);
  	iim_base = of_iomap(np, 0);
  	WARN_ON(!iim_base);
  
  	srev = readl(iim_base + IIM_SREV) & 0xff;
  
  	iounmap(iim_base);
  
  	return srev;
  }
  
  static int get_mx51_srev(void)
  {
  	u32 rev = imx5_read_srev_reg("fsl,imx51-iim");
  
  	switch (rev) {
  	case 0x0:
  		return IMX_CHIP_REVISION_2_0;
  	case 0x10:
  		return IMX_CHIP_REVISION_3_0;
  	default:
  		return IMX_CHIP_REVISION_UNKNOWN;
  	}
  }
  
  /*
   * Returns:
   *	the silicon revision of the cpu
   *	-EINVAL - not a mx51
   */
  int mx51_revision(void)
  {
  	if (!cpu_is_mx51())
  		return -EINVAL;
  
  	if (mx5_cpu_rev == -1)
  		mx5_cpu_rev = get_mx51_srev();
  
  	return mx5_cpu_rev;
  }
  EXPORT_SYMBOL(mx51_revision);
  
  #ifdef CONFIG_NEON
  
  /*
   * All versions of the silicon before Rev. 3 have broken NEON implementations.
   * Dependent on link order - so the assumption is that vfp_init is called
   * before us.
   */
  int __init mx51_neon_fixup(void)
  {
  	if (mx51_revision() < IMX_CHIP_REVISION_3_0 &&
  			(elf_hwcap & HWCAP_NEON)) {
  		elf_hwcap &= ~HWCAP_NEON;
  		pr_info("Turning off NEON support, detected broken NEON implementation
  ");
  	}
  	return 0;
  }
  
  #endif
  
  static int get_mx53_srev(void)
  {
  	u32 rev = imx5_read_srev_reg("fsl,imx53-iim");
  
  	switch (rev) {
  	case 0x0:
  		return IMX_CHIP_REVISION_1_0;
  	case 0x2:
  		return IMX_CHIP_REVISION_2_0;
  	case 0x3:
  		return IMX_CHIP_REVISION_2_1;
  	default:
  		return IMX_CHIP_REVISION_UNKNOWN;
  	}
  }
  
  /*
   * Returns:
   *	the silicon revision of the cpu
   *	-EINVAL - not a mx53
   */
  int mx53_revision(void)
  {
  	if (!cpu_is_mx53())
  		return -EINVAL;
  
  	if (mx5_cpu_rev == -1)
  		mx5_cpu_rev = get_mx53_srev();
  
  	return mx5_cpu_rev;
  }
  EXPORT_SYMBOL(mx53_revision);