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 17 #ifndef DEBUG_IMX_CCM 18 #define DEBUG_IMX_CCM 0 19 #endif 20 21 #define DPRINTF(fmt, args...) \ 22 do { \ 23 if (DEBUG_IMX_CCM) { \ 24 fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX_CCM, \ 25 __func__, ##args); \ 26 } \ 27 } while (0) 28 29 30 uint32_t imx_ccm_get_clock_frequency(IMXCCMState *dev, IMXClk clock) 31 { 32 uint32_t freq = 0; 33 IMXCCMClass *klass = IMX_GET_CLASS(dev); 34 35 if (klass->get_clock_frequency) { 36 freq = klass->get_clock_frequency(dev, clock); 37 } 38 39 DPRINTF("(clock = %d) = %d\n", clock, freq); 40 41 return freq; 42 } 43 44 /* 45 * Calculate PLL output frequency 46 */ 47 uint32_t imx_ccm_calc_pll(uint32_t pllreg, uint32_t base_freq) 48 { 49 int32_t freq; 50 int32_t mfn = MFN(pllreg); /* Numerator */ 51 uint32_t mfi = MFI(pllreg); /* Integer part */ 52 uint32_t mfd = 1 + MFD(pllreg); /* Denominator */ 53 uint32_t pd = 1 + PD(pllreg); /* Pre-divider */ 54 55 if (mfi < 5) { 56 mfi = 5; 57 } 58 59 /* mfn is 10-bit signed twos-complement */ 60 mfn <<= 32 - 10; 61 mfn >>= 32 - 10; 62 63 freq = ((2 * (base_freq >> 10) * (mfi * mfd + mfn)) / 64 (mfd * pd)) << 10; 65 66 DPRINTF("(pllreg = 0x%08x, base_freq = %d) = %d\n", pllreg, base_freq, 67 freq); 68 69 return freq; 70 } 71 72 static const TypeInfo imx_ccm_info = { 73 .name = TYPE_IMX_CCM, 74 .parent = TYPE_SYS_BUS_DEVICE, 75 .instance_size = sizeof(IMXCCMState), 76 .class_size = sizeof(IMXCCMClass), 77 .abstract = true, 78 }; 79 80 static void imx_ccm_register_types(void) 81 { 82 type_register_static(&imx_ccm_info); 83 } 84 85 type_init(imx_ccm_register_types) 86