qemu

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imx_ccm.c (2090B)

      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/module.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 
     31 uint32_t imx_ccm_get_clock_frequency(IMXCCMState *dev, IMXClk clock)
     32 {
     33     uint32_t freq = 0;
     34     IMXCCMClass *klass = IMX_CCM_GET_CLASS(dev);
     35 
     36     if (klass->get_clock_frequency) {
     37         freq = klass->get_clock_frequency(dev, clock);
     38     }
     39 
     40     DPRINTF("(clock = %d) = %u\n", clock, freq);
     41 
     42     return freq;
     43 }
     44 
     45 /*
     46  * Calculate PLL output frequency
     47  */
     48 uint32_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 = %u) = %d\n", pllreg, base_freq,
     68             freq);
     69 
     70     return freq;
     71 }
     72 
     73 static 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 
     81 static void imx_ccm_register_types(void)
     82 {
     83     type_register_static(&imx_ccm_info);
     84 }
     85 
     86 type_init(imx_ccm_register_types)