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) 87