LXR qemu/hw/misc/imx

   1/*
   2 * IMX31 Clock Control Module
   3 *
   4 * Copyright (C) 2012 NICTA
   5 * Updated by Jean-Christophe Dubois <jcd@tribudubois.net>
   6 *
   7 * This work is licensed under the terms of the GNU GPL, version 2 or later.
   8 * See the COPYING file in the top-level directory.
   9 *
  10 * This is an abstract base class used to get a common interface to
  11 * retrieve the CCM frequencies from the various i.MX SOC.
  12 */
  13
  14#include "qemu/osdep.h"
  15#include "hw/misc/imx_ccm.h"
  16#include "qemu/log.h"
  17
  18#ifndef DEBUG_IMX_CCM
  19#define DEBUG_IMX_CCM 0
  20#endif
  21
  22#define DPRINTF(fmt, args...) \
  23    do { \
  24        if (DEBUG_IMX_CCM) { \
  25            fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX_CCM, \
  26                                             __func__, ##args); \
  27        } \
  28    } while (0)
  29
  30
  31uint32_t imx_ccm_get_clock_frequency(IMXCCMState *dev, IMXClk clock)
  32{
  33    uint32_t freq = 0;
  34    IMXCCMClass *klass = IMX_GET_CLASS(dev);
  35
  36    if (klass->get_clock_frequency) {
  37        freq = klass->get_clock_frequency(dev, clock);
  38    }
  39
  40    DPRINTF("(clock = %d) = %d\n", clock, freq);
  41
  42    return freq;
  43}
  44
  45/*
  46 * Calculate PLL output frequency
  47 */
  48uint32_t imx_ccm_calc_pll(uint32_t pllreg, uint32_t base_freq)
  49{
  50    int32_t freq;
  51    int32_t mfn = MFN(pllreg);  /* Numerator */
  52    uint32_t mfi = MFI(pllreg); /* Integer part */
  53    uint32_t mfd = 1 + MFD(pllreg); /* Denominator */
  54    uint32_t pd = 1 + PD(pllreg);   /* Pre-divider */
  55
  56    if (mfi < 5) {
  57        mfi = 5;
  58    }
  59
  60    /* mfn is 10-bit signed twos-complement */
  61    mfn <<= 32 - 10;
  62    mfn >>= 32 - 10;
  63
  64    freq = ((2 * (base_freq >> 10) * (mfi * mfd + mfn)) /
  65            (mfd * pd)) << 10;
  66
  67    DPRINTF("(pllreg = 0x%08x, base_freq = %d) = %d\n", pllreg, base_freq,
  68            freq);
  69
  70    return freq;
  71}
  72
  73static const TypeInfo imx_ccm_info = {
  74    .name          = TYPE_IMX_CCM,
  75    .parent        = TYPE_SYS_BUS_DEVICE,
  76    .instance_size = sizeof(IMXCCMState),
  77    .class_size    = sizeof(IMXCCMClass),
  78    .abstract      = true,
  79};
  80
  81static void imx_ccm_register_types(void)
  82{
  83    type_register_static(&imx_ccm_info);
  84}
  85
  86type_init(imx_ccm_register_types)
  87