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kernel/linux-imx6_3.14.28/arch/arm/mach-omap2/clock3xxx.c 2.51 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
   * OMAP3-specific clock framework functions
   *
   * Copyright (C) 2007-2008 Texas Instruments, Inc.
   * Copyright (C) 2007-2010 Nokia Corporation
   *
   * Paul Walmsley
   * Jouni Högander
   *
   * Parts of this code are based on code written by
   * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu
   *
   * 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.
   */
  #undef DEBUG
  
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/clk.h>
  #include <linux/io.h>
  
  #include "soc.h"
  #include "clock.h"
  #include "clock3xxx.h"
  #include "prm2xxx_3xxx.h"
  #include "prm-regbits-34xx.h"
  #include "cm2xxx_3xxx.h"
  #include "cm-regbits-34xx.h"
  
  /*
   * DPLL5_FREQ_FOR_USBHOST: USBHOST and USBTLL are the only clocks
   * that are sourced by DPLL5, and both of these require this clock
   * to be at 120 MHz for proper operation.
   */
  #define DPLL5_FREQ_FOR_USBHOST		120000000
  
  /* needed by omap3_core_dpll_m2_set_rate() */
  struct clk *sdrc_ick_p, *arm_fck_p;
  int omap3_dpll4_set_rate(struct clk_hw *hw, unsigned long rate,
  				unsigned long parent_rate)
  {
  	/*
  	 * According to the 12-5 CDP code from TI, "Limitation 2.5"
  	 * on 3430ES1 prevents us from changing DPLL multipliers or dividers
  	 * on DPLL4.
  	 */
  	if (omap_rev() == OMAP3430_REV_ES1_0) {
  		pr_err("clock: DPLL4 cannot change rate due to silicon 'Limitation 2.5' on 3430ES1.
  ");
  		return -EINVAL;
  	}
  
  	return omap3_noncore_dpll_set_rate(hw, rate, parent_rate);
  }
  
  void __init omap3_clk_lock_dpll5(void)
  {
  	struct clk *dpll5_clk;
  	struct clk *dpll5_m2_clk;
  
  	dpll5_clk = clk_get(NULL, "dpll5_ck");
  	clk_set_rate(dpll5_clk, DPLL5_FREQ_FOR_USBHOST);
  	clk_prepare_enable(dpll5_clk);
  
  	/* Program dpll5_m2_clk divider for no division */
  	dpll5_m2_clk = clk_get(NULL, "dpll5_m2_ck");
  	clk_prepare_enable(dpll5_m2_clk);
  	clk_set_rate(dpll5_m2_clk, DPLL5_FREQ_FOR_USBHOST);
  
  	clk_disable_unprepare(dpll5_m2_clk);
  	clk_disable_unprepare(dpll5_clk);
  	return;
  }
  
  /* Common clock code */
  
  /*
   * Switch the MPU rate if specified on cmdline.  We cannot do this
   * early until cmdline is parsed.  XXX This should be removed from the
   * clock code and handled by the OPP layer code in the near future.
   */
  static int __init omap3xxx_clk_arch_init(void)
  {
  	int ret;
  
  	if (!cpu_is_omap34xx())
  		return 0;
  
  	ret = omap2_clk_switch_mpurate_at_boot("dpll1_ck");
  	if (!ret)
  		omap2_clk_print_new_rates("osc_sys_ck", "core_ck", "arm_fck");
  
  	return ret;
  }
  
  omap_arch_initcall(omap3xxx_clk_arch_init);