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kernel/linux-imx6_3.14.28/arch/powerpc/boot/pq2.c 2.37 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
   * PowerQUICC II support functions
   *
   * Author: Scott Wood <scottwood@freescale.com>
   *
   * Copyright (c) 2007 Freescale Semiconductor, Inc.
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published
   * by the Free Software Foundation.
   */
  
  #include "ops.h"
  #include "types.h"
  #include "fsl-soc.h"
  #include "pq2.h"
  #include "stdio.h"
  #include "io.h"
  
  #define PQ2_SCCR (0x10c80/4) /* System Clock Configuration Register */
  #define PQ2_SCMR (0x10c88/4) /* System Clock Mode Register */
  
  static int pq2_corecnf_map[] = {
  	3, 2, 2, 2, 4, 4, 5, 9, 6, 11, 8, 10, 3, 12, 7, -1,
  	6, 5, 13, 2, 14, 4, 15, 9, 0, 11, 8, 10, 16, 12, 7, -1
  };
  
  /* Get various clocks from crystal frequency.
   * Returns zero on failure and non-zero on success.
   */
  int pq2_get_clocks(u32 crystal, u32 *sysfreq, u32 *corefreq,
                     u32 *timebase, u32 *brgfreq)
  {
  	u32 *immr;
  	u32 sccr, scmr, mainclk, busclk;
  	int corecnf, busdf, plldf, pllmf, dfbrg;
  
  	immr = fsl_get_immr();
  	if (!immr) {
  		printf("pq2_get_clocks: Couldn't get IMMR base.\r
  ");
  		return 0;
  	}
  
  	sccr = in_be32(&immr[PQ2_SCCR]);
  	scmr = in_be32(&immr[PQ2_SCMR]);
  
  	dfbrg = sccr & 3;
  	corecnf = (scmr >> 24) & 0x1f;
  	busdf = (scmr >> 20) & 0xf;
  	plldf = (scmr >> 12) & 1;
  	pllmf = scmr & 0xfff;
  
  	mainclk = crystal * (pllmf + 1) / (plldf + 1);
  	busclk = mainclk / (busdf + 1);
  
  	if (sysfreq)
  		*sysfreq = mainclk / 2;
  	if (timebase)
  		*timebase = busclk / 4;
  	if (brgfreq)
  		*brgfreq = mainclk / (1 << ((dfbrg + 1) * 2));
  
  	if (corefreq) {
  		int coremult = pq2_corecnf_map[corecnf];
  
  		if (coremult < 0)
  			*corefreq = mainclk / 2;
  		else if (coremult == 0)
  			return 0;
  		else
  			*corefreq = busclk * coremult / 2;
  	}
  
  	return 1;
  }
  
  /* Set common device tree fields based on the given clock frequencies. */
  void pq2_set_clocks(u32 sysfreq, u32 corefreq, u32 timebase, u32 brgfreq)
  {
  	void *node;
  
  	dt_fixup_cpu_clocks(corefreq, timebase, sysfreq);
  
  	node = finddevice("/soc/cpm");
  	if (node)
  		setprop(node, "clock-frequency", &sysfreq, 4);
  
  	node = finddevice("/soc/cpm/brg");
  	if (node)
  		setprop(node, "clock-frequency", &brgfreq, 4);
  }
  
  int pq2_fixup_clocks(u32 crystal)
  {
  	u32 sysfreq, corefreq, timebase, brgfreq;
  
  	if (!pq2_get_clocks(crystal, &sysfreq, &corefreq, &timebase, &brgfreq))
  		return 0;
  
  	pq2_set_clocks(sysfreq, corefreq, timebase, brgfreq);
  	return 1;
  }