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kernel/linux-imx6_3.14.28/arch/mips/bcm47xx/time.c 2.5 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
   *  Copyright (C) 2004 Florian Schirmer <jolt@tuxbox.org>
   *
   *  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  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
   *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
   *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
   *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
   *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
   *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
   *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   *  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.,
   *  675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  
  #include <linux/init.h>
  #include <linux/ssb/ssb.h>
  #include <asm/time.h>
  #include <bcm47xx.h>
  #include <bcm47xx_nvram.h>
  #include <bcm47xx_board.h>
  
  void __init plat_time_init(void)
  {
  	unsigned long hz = 0;
  	u16 chip_id = 0;
  	char buf[10];
  	int len;
  	enum bcm47xx_board board = bcm47xx_board_get();
  
  	/*
  	 * Use deterministic values for initial counter interrupt
  	 * so that calibrate delay avoids encountering a counter wrap.
  	 */
  	write_c0_count(0);
  	write_c0_compare(0xffff);
  
  	switch (bcm47xx_bus_type) {
  #ifdef CONFIG_BCM47XX_SSB
  	case BCM47XX_BUS_TYPE_SSB:
  		hz = ssb_cpu_clock(&bcm47xx_bus.ssb.mipscore) / 2;
  		chip_id = bcm47xx_bus.ssb.chip_id;
  		break;
  #endif
  #ifdef CONFIG_BCM47XX_BCMA
  	case BCM47XX_BUS_TYPE_BCMA:
  		hz = bcma_cpu_clock(&bcm47xx_bus.bcma.bus.drv_mips) / 2;
  		chip_id = bcm47xx_bus.bcma.bus.chipinfo.id;
  		break;
  #endif
  	}
  
  	if (chip_id == 0x5354) {
  		len = bcm47xx_nvram_getenv("clkfreq", buf, sizeof(buf));
  		if (len >= 0 && !strncmp(buf, "200", 4))
  			hz = 100000000;
  	}
  
  	switch (board) {
  	case BCM47XX_BOARD_ASUS_WL520GC:
  	case BCM47XX_BOARD_ASUS_WL520GU:
  		hz = 100000000;
  		break;
  	default:
  		break;
  	}
  
  	if (!hz)
  		hz = 100000000;
  
  	/* Set MIPS counter frequency for fixed_rate_gettimeoffset() */
  	mips_hpt_frequency = hz;
  }