1 // SPDX-License-Identifier: GPL-2.0-only
3  * (C) 2002 - 2003  Dominik Brodowski <linux@brodo.de>
23  * performance_pctg = (current_freq - low_freq)/(high_freq - low_freq)
29  * longrun_get_policy - get the current LongRun policy
40 	pr_debug("longrun flags are %x - %x\n", msr_lo, msr_hi);  in longrun_get_policy()
42 		policy->policy = CPUFREQ_POLICY_PERFORMANCE;  in longrun_get_policy()
44 		policy->policy = CPUFREQ_POLICY_POWERSAVE;  in longrun_get_policy()
47 	pr_debug("longrun ctrl is %x - %x\n", msr_lo, msr_hi);  in longrun_get_policy()
53 		policy->min = policy->max = longrun_high_freq;  in longrun_get_policy()
55 		policy->min = longrun_low_freq + msr_lo *  in longrun_get_policy()
56 			((longrun_high_freq - longrun_low_freq) / 100);  in longrun_get_policy()
57 		policy->max = longrun_low_freq + msr_hi *  in longrun_get_policy()
58 			((longrun_high_freq - longrun_low_freq) / 100);  in longrun_get_policy()
60 	policy->cpu = 0;  in longrun_get_policy()
65  * longrun_set_policy - sets a new CPUFreq policy
68  * Sets a new CPUFreq policy on LongRun-capable processors. This function
77 		return -EINVAL;  in longrun_set_policy()
83 		pctg_lo = (policy->min - longrun_low_freq) /  in longrun_set_policy()
84 			((longrun_high_freq - longrun_low_freq) / 100);  in longrun_set_policy()
85 		pctg_hi = (policy->max - longrun_low_freq) /  in longrun_set_policy()
86 			((longrun_high_freq - longrun_low_freq) / 100);  in longrun_set_policy()
97 	switch (policy->policy) {  in longrun_set_policy()
119  * longrun_verify_poliy - verifies a new CPUFreq policy
128 		return -EINVAL;  in longrun_verify_policy()
130 	policy->cpu = 0;  in longrun_verify_policy()
138 	u32 eax, ebx, ecx, edx;  in longrun_get()  local
143 	cpuid(0x80860007, &eax, &ebx, &ecx, &edx);  in longrun_get()
146 	return eax * 1000;  in longrun_get()
150  * longrun_determine_freqs - determines the lowest and highest possible core frequency
157  * performance_pctg = (target_freq - low_freq)/(high_freq - low_freq)
164 	u32 eax, ebx, ecx, edx;  in longrun_determine_freqs()  local
169 		return -EINVAL;  in longrun_determine_freqs()
183 		*low_freq = msr_lo * 1000; /* to kHz */  in longrun_determine_freqs()
188 		*high_freq = msr_lo * 1000; /* to kHz */  in longrun_determine_freqs()
190 		pr_debug("longrun table interface told %u - %u kHz\n",  in longrun_determine_freqs()
199 	*high_freq = (cpu_khz / 1000);  in longrun_determine_freqs()
200 	*high_freq = *high_freq * 1000;  in longrun_determine_freqs()
211 	cpuid(0x80860007, &eax, &ebx, &ecx, &edx);  in longrun_determine_freqs()
214 	for (try_hi = 80; try_hi > 0 && ecx > 90; try_hi -= 10) {  in longrun_determine_freqs()
222 		cpuid(0x80860007, &eax, &ebx, &ecx, &edx);  in longrun_determine_freqs()
227 	pr_debug("percentage is %u %%, freq is %u MHz\n", ecx, eax);  in longrun_determine_freqs()
229 	/* performance_pctg = (current_freq - low_freq)/(high_freq - low_freq)  in longrun_determine_freqs()
231 	 * low_freq * (1 - perf_pctg) = (cur_freq - high_freq * perf_pctg)  in longrun_determine_freqs()
235 	ebx = (((cpu_khz / 1000) * ecx) / 100); /* to MHz */  in longrun_determine_freqs()
237 	if ((ecx > 95) || (ecx == 0) || (eax < ebx))  in longrun_determine_freqs()
238 		return -EIO;  in longrun_determine_freqs()
240 	edx = ((eax - ebx) * 100) / (100 - ecx);  in longrun_determine_freqs()
241 	*low_freq = edx * 1000; /* back to kHz */  in longrun_determine_freqs()
257 	if (policy->cpu != 0)  in longrun_cpu_init()
258 		return -ENODEV;  in longrun_cpu_init()
266 	policy->cpuinfo.min_freq = longrun_low_freq;  in longrun_cpu_init()
267 	policy->cpuinfo.max_freq = longrun_high_freq;  in longrun_cpu_init()
290  * longrun_init - initializes the Transmeta Crusoe LongRun CPUFreq driver
297 		return -ENODEV;  in longrun_init()
303  * longrun_exit - unregisters LongRun support