/* * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * pe_clock_speed.c - Determine the best guess for the processor and bus * speed buy using the values returned by run_clock_test. * * (c) Apple Computer, Inc. 1998-2002 * * Writen by: Josh de Cesare * */ #include #include // prototypes extern void pe_run_clock_test(void *tmp); void pe_do_clock_test(unsigned int via_addr, int num_speeds, unsigned long *speed_list); void PE_Determine_Clock_Speeds(unsigned int via_addr, int num_speeds, unsigned long *speed_list); // Threshold for bus speed matches. #define kMaxFreqDiff (30000) // This is the structure for the data that get passed to pe_run_clock_test. struct clock_test_data { unsigned int via_addr; unsigned int via_ticks; unsigned int dec_ticks; }; // glocal variables to simplify some stuff. static long bus_freq_num, bus_freq_den, cpu_pll; // PE_Determine_Clock_Speeds is called by the via driver in IOKit // It uses the numbers generated by pe_do_clock_test and reports // the cleaned up values to the rest of the OS. void PE_Determine_Clock_Speeds(unsigned int via_addr, int num_speeds, unsigned long *speed_list) { boolean_t oldLevel; unsigned long tmp_bus_speed, tmp_cpu_speed; unsigned long long tmp; oldLevel = ml_set_interrupts_enabled(FALSE); pe_do_clock_test(via_addr, num_speeds, speed_list); ml_set_interrupts_enabled(oldLevel); tmp_bus_speed = bus_freq_num / bus_freq_den; tmp = ((unsigned long long)bus_freq_num * cpu_pll) / (bus_freq_den * 2); tmp_cpu_speed = (unsigned long)tmp; // Report the bus clock rate as is. gPEClockFrequencyInfo.bus_clock_rate_num = bus_freq_num; gPEClockFrequencyInfo.bus_clock_rate_den = bus_freq_den; // pll multipliers are in halfs so set the denominator to 2. gPEClockFrequencyInfo.bus_to_cpu_rate_num = cpu_pll; gPEClockFrequencyInfo.bus_to_cpu_rate_den = 2; // The decrementer rate is one fourth the bus rate. gPEClockFrequencyInfo.bus_to_dec_rate_num = 1; gPEClockFrequencyInfo.bus_to_dec_rate_den = 4; // Assume that the timebase frequency is derived from the bus clock. gPEClockFrequencyInfo.timebase_frequency_num = bus_freq_num; gPEClockFrequencyInfo.timebase_frequency_den = bus_freq_den * 4; // Set the truncated numbers in gPEClockFrequencyInfo. gPEClockFrequencyInfo.bus_clock_rate_hz = tmp_bus_speed; gPEClockFrequencyInfo.cpu_clock_rate_hz = tmp_cpu_speed; gPEClockFrequencyInfo.dec_clock_rate_hz = tmp_bus_speed / 4; gPEClockFrequencyInfo.timebase_frequency_hz = tmp_bus_speed / 4; gPEClockFrequencyInfo.bus_frequency_hz = tmp_bus_speed; gPEClockFrequencyInfo.bus_frequency_min_hz = tmp_bus_speed; gPEClockFrequencyInfo.bus_frequency_max_hz = tmp_bus_speed; gPEClockFrequencyInfo.cpu_frequency_hz = tmp_cpu_speed; gPEClockFrequencyInfo.cpu_frequency_min_hz = tmp_cpu_speed; gPEClockFrequencyInfo.cpu_frequency_max_hz = tmp_cpu_speed; PE_call_timebase_callback(); } // pe_do_clock_test uses the number from pe_run_clock_test to // find a best fit guess for the bus speed. void pe_do_clock_test(unsigned int via_addr, int num_speeds, unsigned long *speed_list) { struct clock_test_data clock_test_data; long cnt, diff, raw_cpu_freq, raw_bus_freq, tmp_bus_freq, last_bus_freq, tries = 10; // Save the via addr so the asm part can use it. clock_test_data.via_addr = via_addr; // Keep looping until it matches the last try. bus_freq_num = 0; do { last_bus_freq = bus_freq_num; // The the asm part to do the real work. pe_run_clock_test((void *)&clock_test_data); // First find the pll mode. Allow any integer times two. cpu_pll = 10000000 / clock_test_data.dec_ticks; cpu_pll = (cpu_pll / 2) + (cpu_pll & 1); // Using 64 bit math figure out the raw bus speed. // 0xBF401675E5DULL is 1 / 1.27655us times 2 ^ 24. raw_bus_freq = ((0xBF401675E5DULL * clock_test_data.dec_ticks) / clock_test_data.via_ticks) >> 22; // use the pll mode and the raw bus speed to find the raw cpu speed. raw_cpu_freq = raw_bus_freq * cpu_pll / 2; // Look to see if the bus speed is close to one of the // speeds in the table. for (cnt = 0; cnt < num_speeds; cnt++) { bus_freq_num = speed_list[cnt * 2]; bus_freq_den = speed_list[cnt * 2 + 1]; diff = bus_freq_num - raw_bus_freq * bus_freq_den; if (diff < 0) diff = -diff; if (diff < kMaxFreqDiff * bus_freq_den) break; } if (cnt != num_speeds) continue; // Look to see if the bus speed is close to n * 0.5 MHz tmp_bus_freq = ((raw_bus_freq + 250000) / 500000) * 500000; diff = tmp_bus_freq - raw_bus_freq; if (diff < 0) diff = -diff; if (diff < kMaxFreqDiff) { bus_freq_num = tmp_bus_freq; bus_freq_den = 1; continue; } // Look to see if the bus speed is close to n * 50/3 MHz tmp_bus_freq = ((raw_bus_freq * 3 + 25000000) / 50000000) * 50000000; diff = tmp_bus_freq - raw_bus_freq * 3; if (diff < 0) diff = -diff; if (diff < kMaxFreqDiff * 3) { bus_freq_num = tmp_bus_freq; bus_freq_den = 3; continue; } // Since all else failed return the raw bus speed bus_freq_num = raw_bus_freq; bus_freq_den = 1; } while ((bus_freq_num != last_bus_freq) && tries--); }