qemu/hw/misc/imx_ccm.c

86 lines
2.0 KiB
C

/*
* IMX31 Clock Control Module
*
* Copyright (C) 2012 NICTA
* Updated by Jean-Christophe Dubois <jcd@tribudubois.net>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
* This is an abstract base class used to get a common interface to
* retrieve the CCM frequencies from the various i.MX SOC.
*/
#include "qemu/osdep.h"
#include "hw/misc/imx_ccm.h"
#ifndef DEBUG_IMX_CCM
#define DEBUG_IMX_CCM 0
#endif
#define DPRINTF(fmt, args...) \
do { \
if (DEBUG_IMX_CCM) { \
fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX_CCM, \
__func__, ##args); \
} \
} while (0)
uint32_t imx_ccm_get_clock_frequency(IMXCCMState *dev, IMXClk clock)
{
uint32_t freq = 0;
IMXCCMClass *klass = IMX_GET_CLASS(dev);
if (klass->get_clock_frequency) {
freq = klass->get_clock_frequency(dev, clock);
}
DPRINTF("(clock = %d) = %d\n", clock, freq);
return freq;
}
/*
* Calculate PLL output frequency
*/
uint32_t imx_ccm_calc_pll(uint32_t pllreg, uint32_t base_freq)
{
int32_t freq;
int32_t mfn = MFN(pllreg); /* Numerator */
uint32_t mfi = MFI(pllreg); /* Integer part */
uint32_t mfd = 1 + MFD(pllreg); /* Denominator */
uint32_t pd = 1 + PD(pllreg); /* Pre-divider */
if (mfi < 5) {
mfi = 5;
}
/* mfn is 10-bit signed twos-complement */
mfn <<= 32 - 10;
mfn >>= 32 - 10;
freq = ((2 * (base_freq >> 10) * (mfi * mfd + mfn)) /
(mfd * pd)) << 10;
DPRINTF("(pllreg = 0x%08x, base_freq = %d) = %d\n", pllreg, base_freq,
freq);
return freq;
}
static const TypeInfo imx_ccm_info = {
.name = TYPE_IMX_CCM,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(IMXCCMState),
.class_size = sizeof(IMXCCMClass),
.abstract = true,
};
static void imx_ccm_register_types(void)
{
type_register_static(&imx_ccm_info);
}
type_init(imx_ccm_register_types)