LXR linux/arch/arm/mach-omap2/clkt2xxx

   1/*
   2 * OMAP2xxx osc_clk-specific clock code
   3 *
   4 * Copyright (C) 2005-2008 Texas Instruments, Inc.
   5 * Copyright (C) 2004-2010 Nokia Corporation
   6 *
   7 * Contacts:
   8 * Richard Woodruff <r-woodruff2@ti.com>
   9 * Paul Walmsley
  10 *
  11 * Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
  12 * Gordon McNutt and RidgeRun, Inc.
  13 *
  14 * This program is free software; you can redistribute it and/or modify
  15 * it under the terms of the GNU General Public License version 2 as
  16 * published by the Free Software Foundation.
  17 */
  18#undef DEBUG
  19
  20#include <linux/module.h>
  21#include <linux/kernel.h>
  22#include <linux/errno.h>
  23#include <linux/clk.h>
  24#include <linux/io.h>
  25
  26#include <plat/clock.h>
  27
  28#include "clock.h"
  29#include "clock2xxx.h"
  30#include "prm2xxx_3xxx.h"
  31#include "prm-regbits-24xx.h"
  32
  33/*
  34 * XXX This does not actually enable the osc_ck, since the osc_ck must
  35 * be running for this function to be called.  Instead, this function
  36 * is used to disable an autoidle mode on the osc_ck.  The existing
  37 * clk_enable/clk_disable()-based usecounting for osc_ck should be
  38 * replaced with autoidle-based usecounting.
  39 */
  40static int omap2_enable_osc_ck(struct clk *clk)
  41{
  42        u32 pcc;
  43
  44        pcc = __raw_readl(prcm_clksrc_ctrl);
  45
  46        __raw_writel(pcc & ~OMAP_AUTOEXTCLKMODE_MASK, prcm_clksrc_ctrl);
  47
  48        return 0;
  49}
  50
  51/*
  52 * XXX This does not actually disable the osc_ck, since doing so would
  53 * immediately halt the system.  Instead, this function is used to
  54 * enable an autoidle mode on the osc_ck.  The existing
  55 * clk_enable/clk_disable()-based usecounting for osc_ck should be
  56 * replaced with autoidle-based usecounting.
  57 */
  58static void omap2_disable_osc_ck(struct clk *clk)
  59{
  60        u32 pcc;
  61
  62        pcc = __raw_readl(prcm_clksrc_ctrl);
  63
  64        __raw_writel(pcc | OMAP_AUTOEXTCLKMODE_MASK, prcm_clksrc_ctrl);
  65}
  66
  67const struct clkops clkops_oscck = {
  68        .enable         = omap2_enable_osc_ck,
  69        .disable        = omap2_disable_osc_ck,
  70};
  71
  72unsigned long omap2_osc_clk_recalc(struct clk *clk)
  73{
  74        return omap2xxx_get_apll_clkin() * omap2xxx_get_sysclkdiv();
  75}
  76
  77