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
imx_ccm_get_clock_frequency(IMXCCMState * dev,IMXClk clock)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 */
imx_ccm_calc_pll(uint32_t pllreg,uint32_t base_freq)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
imx_ccm_register_types(void)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)
87