1 // SPDX-License-Identifier: GPL-2.0-only
5  *	(C) 2002 Hiroshi Miura   <miura@da-cha.org>
10  *      software is provided AS-IS with no warranties.
19  *	Suspend Modulation works by asserting and de-asserting the SUSP# pin
20  *	to CPU(GX1/GXLV) for configurable durations. When asserting SUSP#
28  *	32us intervals which the SUSP# pin is asserted(ON)/de-asserted(OFF)
35  *	F_eff = Fgx * ----------------------
43  *	on_duration = off_duration * (stock_freq - freq) / freq
46  *      on_duration = DURATION - off_duration
48  *---------------------------------------------------------------------------
51  *	Dec. 12, 2003	Hiroshi Miura <miura@da-cha.org>
52  *		- fix on/off register mistake
53  *		- fix cpu_khz calc when it stops cpu modulation.
55  *	Dec. 11, 2002	Hiroshi Miura <miura@da-cha.org>
56  *		- rewrite for Cyrix MediaGX Cx5510/5520 and
60  *		- cs5530_mod patch for 2.4.19-rc1.
62  *---------------------------------------------------------------------------
69  *			Suspend Modulation - Definitions		*
82 #include <asm/processor-cyrix.h>
104 #define SMISPDUP	(1<<1)	/* select how SMI re-enable suspend modulation: */
105 				/* IRQTC timer or read SMI speedup disable reg.(F1BAR[08-09h]) */
123 /* PCI bus clock - defaults to 30.000 if cpu_khz is not available */
131  * is suspended -- processing power is just 0.39% of what it used to be,
132  * though. 781.25 kHz(!) for a 200 MHz processor -- wow. */
137  * - let's say 5%. (min = maxfreq / POLICY_MIN_DIV)
175 	pci_write_config_byte(gx_params->cs55x0, reg, value);  in gx_write_byte()
204 	if ((gx_params->pci_suscfg & SUSMOD) == 0)  in gx_get_cpuspeed()
207 	return (stock_freq * gx_params->off_duration)  in gx_get_cpuspeed()
208 		/ (gx_params->on_duration + gx_params->off_duration);  in gx_get_cpuspeed()
228 	for (i = max_duration; i > 0; i--) {  in gx_validate_speed()
230 		tmp_on = i - tmp_off;  in gx_validate_speed()
233 		 * prefer it, too - lower latency */  in gx_validate_speed()
234 		if (abs(tmp_freq - khz) <= abs(old_tmp_freq - khz)) {  in gx_validate_speed()
259 	new_khz = gx_validate_speed(khz, &gx_params->on_duration,  in gx_set_cpuspeed()
260 			&gx_params->off_duration);  in gx_set_cpuspeed()
269 		switch (gx_params->cs55x0->device) {  in gx_set_cpuspeed()
271 			pmer1 = gx_params->pci_pmer1 | IRQ_SPDUP | VID_SPDUP;  in gx_set_cpuspeed()
272 			/* FIXME: need to test other values -- Zwane,Miura */  in gx_set_cpuspeed()
279 			if (gx_params->cs55x0->revision < 0x10) {  in gx_set_cpuspeed()
281 				suscfg = gx_params->pci_suscfg|SUSMOD;  in gx_set_cpuspeed()
284 				suscfg = gx_params->pci_suscfg|SUSMOD|PWRSVE;  in gx_set_cpuspeed()
289 			suscfg = gx_params->pci_suscfg | SUSMOD;  in gx_set_cpuspeed()
297 		suscfg = gx_params->pci_suscfg & ~(SUSMOD);  in gx_set_cpuspeed()
298 		gx_params->off_duration = 0;  in gx_set_cpuspeed()
299 		gx_params->on_duration = 0;  in gx_set_cpuspeed()
303 	gx_write_byte(PCI_MODOFF, gx_params->off_duration);  in gx_set_cpuspeed()
304 	gx_write_byte(PCI_MODON, gx_params->on_duration);  in gx_set_cpuspeed()
307 	pci_read_config_byte(gx_params->cs55x0, PCI_SUSCFG, &suscfg);  in gx_set_cpuspeed()
311 	gx_params->pci_suscfg = suscfg;  in gx_set_cpuspeed()
316 		gx_params->on_duration * 32, gx_params->off_duration * 32);  in gx_set_cpuspeed()
337 		return -EINVAL;  in cpufreq_gx_verify()
339 	policy->cpu = 0;  in cpufreq_gx_verify()
344 	 * within policy->min and policy->max. If it is not, policy->max  in cpufreq_gx_verify()
346 	 * policy->min may not be decreased, though. This way we guarantee a  in cpufreq_gx_verify()
349 	tmp_freq = gx_validate_speed(policy->min, &tmp1, &tmp2);  in cpufreq_gx_verify()
350 	if (tmp_freq < policy->min)  in cpufreq_gx_verify()
352 	policy->min = tmp_freq;  in cpufreq_gx_verify()
353 	if (policy->min > policy->max)  in cpufreq_gx_verify()
354 		policy->max = tmp_freq;  in cpufreq_gx_verify()
355 	tmp_freq = gx_validate_speed(policy->max, &tmp1, &tmp2);  in cpufreq_gx_verify()
356 	if (tmp_freq > policy->max)  in cpufreq_gx_verify()
357 		tmp_freq -= stock_freq / max_duration;  in cpufreq_gx_verify()
358 	policy->max = tmp_freq;  in cpufreq_gx_verify()
359 	if (policy->max < policy->min)  in cpufreq_gx_verify()
360 		policy->max = policy->min;  in cpufreq_gx_verify()
379 		return -EINVAL;  in cpufreq_gx_target()
381 	policy->cpu = 0;  in cpufreq_gx_target()
384 	while (tmp_freq < policy->min) {  in cpufreq_gx_target()
388 	while (tmp_freq > policy->max) {  in cpufreq_gx_target()
389 		tmp_freq -= stock_freq / max_duration;  in cpufreq_gx_target()
402 	if (!policy || policy->cpu != 0)  in cpufreq_gx_cpu_init()
403 		return -ENODEV;  in cpufreq_gx_cpu_init()
418 	policy->cpu = 0;  in cpufreq_gx_cpu_init()
421 		policy->min = maxfreq / max_duration;  in cpufreq_gx_cpu_init()
423 		policy->min = maxfreq / POLICY_MIN_DIV;  in cpufreq_gx_cpu_init()
424 	policy->max = maxfreq;  in cpufreq_gx_cpu_init()
425 	policy->cpuinfo.min_freq = maxfreq / max_duration;  in cpufreq_gx_cpu_init()
426 	policy->cpuinfo.max_freq = maxfreq;  in cpufreq_gx_cpu_init()
441 	.name		= "gx-suspmod",
453 		return -ENODEV;  in cpufreq_gx_init()
463 		return -ENOMEM;  in cpufreq_gx_init()
465 	params->cs55x0 = gx_pci;  in cpufreq_gx_init()
469 	pci_read_config_byte(params->cs55x0, PCI_SUSCFG, &(params->pci_suscfg));  in cpufreq_gx_init()
470 	pci_read_config_byte(params->cs55x0, PCI_PMER1, &(params->pci_pmer1));  in cpufreq_gx_init()
471 	pci_read_config_byte(params->cs55x0, PCI_PMER2, &(params->pci_pmer2));  in cpufreq_gx_init()
472 	pci_read_config_byte(params->cs55x0, PCI_MODON, &(params->on_duration));  in cpufreq_gx_init()
473 	pci_read_config_byte(params->cs55x0, PCI_MODOFF,  in cpufreq_gx_init()
474 			&(params->off_duration));  in cpufreq_gx_init()
488 	pci_dev_put(gx_params->cs55x0);  in cpufreq_gx_exit()
492 MODULE_AUTHOR("Hiroshi Miura <miura@da-cha.org>");