| 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 | #include "trace.h" |
| 18 | |
| 19 | |
| 20 | uint32_t imx_ccm_get_clock_frequency(IMXCCMState *dev, IMXClk clock) |
| 21 | { |
| 22 | uint32_t freq = 0; |
| 23 | IMXCCMClass *klass = IMX_CCM_GET_CLASS(dev); |
| 24 | |
| 25 | if (klass->get_clock_frequency) { |
| 26 | freq = klass->get_clock_frequency(dev, clock); |
| 27 | } |
| 28 | |
| 29 | trace_imx_ccm_get_clock_frequency(clock, freq); |
| 30 | |
| 31 | return freq; |
| 32 | } |
| 33 | |
| 34 | /* |
| 35 | * Calculate PLL output frequency |
| 36 | */ |
| 37 | uint32_t imx_ccm_calc_pll(uint32_t pllreg, uint32_t base_freq) |
| 38 | { |
| 39 | int32_t freq; |
| 40 | int32_t mfn = MFN(pllreg); /* Numerator */ |
| 41 | uint32_t mfi = MFI(pllreg); /* Integer part */ |
| 42 | uint32_t mfd = 1 + MFD(pllreg); /* Denominator */ |
| 43 | uint32_t pd = 1 + PD(pllreg); /* Pre-divider */ |
| 44 | |
| 45 | if (mfi < 5) { |
| 46 | mfi = 5; |
| 47 | } |
| 48 | |
| 49 | /* mfn is 10-bit signed twos-complement */ |
| 50 | mfn <<= 32 - 10; |
| 51 | mfn >>= 32 - 10; |
| 52 | |
| 53 | freq = ((2 * (base_freq >> 10) * (mfi * mfd + mfn)) / |
| 54 | (mfd * pd)) << 10; |
| 55 | |
| 56 | trace_imx_ccm_calc_pll(pllreg, base_freq, freq); |
| 57 | |
| 58 | return freq; |
| 59 | } |
| 60 | |
| 61 | static const TypeInfo imx_ccm_info = { |
| 62 | .name = TYPE_IMX_CCM, |
| 63 | .parent = TYPE_SYS_BUS_DEVICE, |
| 64 | .instance_size = sizeof(IMXCCMState), |
| 65 | .class_size = sizeof(IMXCCMClass), |
| 66 | .abstract = true, |
| 67 | }; |
| 68 | |
| 69 | static void imx_ccm_register_types(void) |
| 70 | { |
| 71 | type_register_static(&imx_ccm_info); |
| 72 | } |
| 73 | |
| 74 | type_init(imx_ccm_register_types) |