xref: /freebsd/sys/dev/cpufreq/ichss.c (revision 1670a1c2a47d10ecccd001970b859caf93cd3b6e)
1 /*-
2  * Copyright (c) 2004-2005 Nate Lawson (SDG)
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/bus.h>
32 #include <sys/cpu.h>
33 #include <sys/kernel.h>
34 #include <sys/malloc.h>
35 #include <sys/module.h>
36 #include <sys/pcpu.h>
37 #include <sys/sysctl.h>
38 #include <sys/systm.h>
39 
40 #include <dev/pci/pcivar.h>
41 #include <machine/bus.h>
42 #include <machine/resource.h>
43 #include <sys/rman.h>
44 
45 #include "cpufreq_if.h"
46 
47 /*
48  * The SpeedStep ICH feature is a chipset-initiated voltage and frequency
49  * transition available on the ICH2M, 3M, and 4M.  It is different from
50  * the newer Pentium-M SpeedStep feature.  It offers only two levels of
51  * frequency/voltage.  Often, the BIOS will select one of the levels via
52  * SMM code during the power-on process (i.e., choose a lower level if the
53  * system is off AC power.)
54  */
55 
56 struct ichss_softc {
57 	device_t	 dev;
58 	int		 bm_rid;	/* Bus-mastering control (PM2REG). */
59 	struct resource	*bm_reg;
60 	int		 ctrl_rid;	/* Control/status register. */
61 	struct resource	*ctrl_reg;
62 	struct cf_setting sets[2];	/* Only two settings. */
63 };
64 
65 /* Supported PCI IDs. */
66 #define PCI_VENDOR_INTEL	0x8086
67 #define PCI_DEV_82801BA		0x244c /* ICH2M */
68 #define PCI_DEV_82801CA		0x248c /* ICH3M */
69 #define PCI_DEV_82801DB		0x24cc /* ICH4M */
70 #define PCI_DEV_82815BA		0x1130 /* Unsupported/buggy part */
71 
72 /* PCI config registers for finding PMBASE and enabling SpeedStep. */
73 #define ICHSS_PMBASE_OFFSET	0x40
74 #define ICHSS_PMCFG_OFFSET	0xa0
75 
76 /* Values and masks. */
77 #define ICHSS_ENABLE		(1<<3)	/* Enable SpeedStep control. */
78 #define ICHSS_IO_REG		0x1	/* Access register via I/O space. */
79 #define ICHSS_PMBASE_MASK	0xff80	/* PMBASE address bits. */
80 #define ICHSS_CTRL_BIT		0x1	/* 0 is high speed, 1 is low. */
81 #define ICHSS_BM_DISABLE	0x1
82 
83 /* Offsets from PMBASE for various registers. */
84 #define ICHSS_BM_OFFSET		0x20
85 #define ICHSS_CTRL_OFFSET	0x50
86 
87 #define ICH_GET_REG(reg) 				\
88 	(bus_space_read_1(rman_get_bustag((reg)), 	\
89 	    rman_get_bushandle((reg)), 0))
90 #define ICH_SET_REG(reg, val)				\
91 	(bus_space_write_1(rman_get_bustag((reg)), 	\
92 	    rman_get_bushandle((reg)), 0, (val)))
93 
94 static void	ichss_identify(driver_t *driver, device_t parent);
95 static int	ichss_probe(device_t dev);
96 static int	ichss_attach(device_t dev);
97 static int	ichss_detach(device_t dev);
98 static int	ichss_settings(device_t dev, struct cf_setting *sets,
99 		    int *count);
100 static int	ichss_set(device_t dev, const struct cf_setting *set);
101 static int	ichss_get(device_t dev, struct cf_setting *set);
102 static int	ichss_type(device_t dev, int *type);
103 
104 static device_method_t ichss_methods[] = {
105 	/* Device interface */
106 	DEVMETHOD(device_identify,	ichss_identify),
107 	DEVMETHOD(device_probe,		ichss_probe),
108 	DEVMETHOD(device_attach,	ichss_attach),
109 	DEVMETHOD(device_detach,	ichss_detach),
110 
111 	/* cpufreq interface */
112 	DEVMETHOD(cpufreq_drv_set,	ichss_set),
113 	DEVMETHOD(cpufreq_drv_get,	ichss_get),
114 	DEVMETHOD(cpufreq_drv_type,	ichss_type),
115 	DEVMETHOD(cpufreq_drv_settings,	ichss_settings),
116 	{0, 0}
117 };
118 static driver_t ichss_driver = {
119 	"ichss", ichss_methods, sizeof(struct ichss_softc)
120 };
121 static devclass_t ichss_devclass;
122 DRIVER_MODULE(ichss, cpu, ichss_driver, ichss_devclass, 0, 0);
123 
124 static device_t ich_device;
125 
126 #if 0
127 #define DPRINT(x...)	printf(x)
128 #else
129 #define DPRINT(x...)
130 #endif
131 
132 static void
133 ichss_identify(driver_t *driver, device_t parent)
134 {
135 	device_t child;
136 	uint32_t pmbase;
137 
138 	if (resource_disabled("ichss", 0))
139 		return;
140 
141 	/*
142 	 * It appears that ICH SpeedStep only requires a single CPU to
143 	 * set the value (since the chipset is shared by all CPUs.)
144 	 * Thus, we only add a child to cpu 0.
145 	 */
146 	if (device_get_unit(parent) != 0)
147 		return;
148 
149 	/* Avoid duplicates. */
150 	if (device_find_child(parent, "ichss", -1))
151 		return;
152 
153 	/*
154 	 * ICH2/3/4-M I/O Controller Hub is at bus 0, slot 1F, function 0.
155 	 * E.g. see Section 6.1 "PCI Devices and Functions" and table 6.1 of
156 	 * Intel(r) 82801BA I/O Controller Hub 2 (ICH2) and Intel(r) 82801BAM
157 	 * I/O Controller Hub 2 Mobile (ICH2-M).
158 	 *
159 	 * TODO: add a quirk to disable if we see the 82815_MC along
160 	 * with the 82801BA and revision < 5.
161 	 */
162 	ich_device = pci_find_bsf(0, 0x1f, 0);
163 	if (ich_device == NULL ||
164 	    pci_get_vendor(ich_device) != PCI_VENDOR_INTEL ||
165 	    (pci_get_device(ich_device) != PCI_DEV_82801BA &&
166 	    pci_get_device(ich_device) != PCI_DEV_82801CA &&
167 	    pci_get_device(ich_device) != PCI_DEV_82801DB))
168 		return;
169 
170 	/* Find the PMBASE register from our PCI config header. */
171 	pmbase = pci_read_config(ich_device, ICHSS_PMBASE_OFFSET,
172 	    sizeof(pmbase));
173 	if ((pmbase & ICHSS_IO_REG) == 0) {
174 		printf("ichss: invalid PMBASE memory type\n");
175 		return;
176 	}
177 	pmbase &= ICHSS_PMBASE_MASK;
178 	if (pmbase == 0) {
179 		printf("ichss: invalid zero PMBASE address\n");
180 		return;
181 	}
182 	DPRINT("ichss: PMBASE is %#x\n", pmbase);
183 
184 	child = BUS_ADD_CHILD(parent, 20, "ichss", 0);
185 	if (child == NULL) {
186 		device_printf(parent, "add SpeedStep child failed\n");
187 		return;
188 	}
189 
190 	/* Add the bus master arbitration and control registers. */
191 	bus_set_resource(child, SYS_RES_IOPORT, 0, pmbase + ICHSS_BM_OFFSET,
192 	    1);
193 	bus_set_resource(child, SYS_RES_IOPORT, 1, pmbase + ICHSS_CTRL_OFFSET,
194 	    1);
195 }
196 
197 static int
198 ichss_probe(device_t dev)
199 {
200 	device_t est_dev, perf_dev;
201 	int error, type;
202 
203 	/*
204 	 * If the ACPI perf driver has attached and is not just offering
205 	 * info, let it manage things.  Also, if Enhanced SpeedStep is
206 	 * available, don't attach.
207 	 */
208 	perf_dev = device_find_child(device_get_parent(dev), "acpi_perf", -1);
209 	if (perf_dev && device_is_attached(perf_dev)) {
210 		error = CPUFREQ_DRV_TYPE(perf_dev, &type);
211 		if (error == 0 && (type & CPUFREQ_FLAG_INFO_ONLY) == 0)
212 			return (ENXIO);
213 	}
214 	est_dev = device_find_child(device_get_parent(dev), "est", -1);
215 	if (est_dev && device_is_attached(est_dev))
216 		return (ENXIO);
217 
218 	device_set_desc(dev, "SpeedStep ICH");
219 	return (-1000);
220 }
221 
222 static int
223 ichss_attach(device_t dev)
224 {
225 	struct ichss_softc *sc;
226 	uint16_t ss_en;
227 
228 	sc = device_get_softc(dev);
229 	sc->dev = dev;
230 
231 	sc->bm_rid = 0;
232 	sc->bm_reg = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &sc->bm_rid,
233 	    RF_ACTIVE);
234 	if (sc->bm_reg == NULL) {
235 		device_printf(dev, "failed to alloc BM arb register\n");
236 		return (ENXIO);
237 	}
238 	sc->ctrl_rid = 1;
239 	sc->ctrl_reg = bus_alloc_resource_any(dev, SYS_RES_IOPORT,
240 	    &sc->ctrl_rid, RF_ACTIVE);
241 	if (sc->ctrl_reg == NULL) {
242 		device_printf(dev, "failed to alloc control register\n");
243 		bus_release_resource(dev, SYS_RES_IOPORT, sc->bm_rid,
244 		    sc->bm_reg);
245 		return (ENXIO);
246 	}
247 
248 	/* Activate SpeedStep control if not already enabled. */
249 	ss_en = pci_read_config(ich_device, ICHSS_PMCFG_OFFSET, sizeof(ss_en));
250 	if ((ss_en & ICHSS_ENABLE) == 0) {
251 		device_printf(dev, "enabling SpeedStep support\n");
252 		pci_write_config(ich_device, ICHSS_PMCFG_OFFSET,
253 		    ss_en | ICHSS_ENABLE, sizeof(ss_en));
254 	}
255 
256 	/* Setup some defaults for our exported settings. */
257 	sc->sets[0].freq = CPUFREQ_VAL_UNKNOWN;
258 	sc->sets[0].volts = CPUFREQ_VAL_UNKNOWN;
259 	sc->sets[0].power = CPUFREQ_VAL_UNKNOWN;
260 	sc->sets[0].lat = 1000;
261 	sc->sets[0].dev = dev;
262 	sc->sets[1] = sc->sets[0];
263 	cpufreq_register(dev);
264 
265 	return (0);
266 }
267 
268 static int
269 ichss_detach(device_t dev)
270 {
271 	/* TODO: teardown BM and CTRL registers. */
272 	return (ENXIO);
273 }
274 
275 static int
276 ichss_settings(device_t dev, struct cf_setting *sets, int *count)
277 {
278 	struct ichss_softc *sc;
279 	struct cf_setting set;
280 	int first, i;
281 
282 	if (sets == NULL || count == NULL)
283 		return (EINVAL);
284 	if (*count < 2) {
285 		*count = 2;
286 		return (E2BIG);
287 	}
288 	sc = device_get_softc(dev);
289 
290 	/*
291 	 * Estimate frequencies for both levels, temporarily switching to
292 	 * the other one if we haven't calibrated it yet.
293 	 */
294 	ichss_get(dev, &set);
295 	for (i = 0; i < 2; i++) {
296 		if (sc->sets[i].freq == CPUFREQ_VAL_UNKNOWN) {
297 			first = (i == 0) ? 1 : 0;
298 			ichss_set(dev, &sc->sets[i]);
299 			ichss_set(dev, &sc->sets[first]);
300 		}
301 	}
302 
303 	bcopy(sc->sets, sets, sizeof(sc->sets));
304 	*count = 2;
305 
306 	return (0);
307 }
308 
309 static int
310 ichss_set(device_t dev, const struct cf_setting *set)
311 {
312 	struct ichss_softc *sc;
313 	uint8_t bmval, new_val, old_val, req_val;
314 	uint64_t rate;
315 	register_t regs;
316 
317 	/* Look up appropriate bit value based on frequency. */
318 	sc = device_get_softc(dev);
319 	if (CPUFREQ_CMP(set->freq, sc->sets[0].freq))
320 		req_val = 0;
321 	else if (CPUFREQ_CMP(set->freq, sc->sets[1].freq))
322 		req_val = ICHSS_CTRL_BIT;
323 	else
324 		return (EINVAL);
325 	DPRINT("ichss: requested setting %d\n", req_val);
326 
327 	/* Disable interrupts and get the other register contents. */
328 	regs = intr_disable();
329 	old_val = ICH_GET_REG(sc->ctrl_reg) & ~ICHSS_CTRL_BIT;
330 
331 	/*
332 	 * Disable bus master arbitration, write the new value to the control
333 	 * register, and then re-enable bus master arbitration.
334 	 */
335 	bmval = ICH_GET_REG(sc->bm_reg) | ICHSS_BM_DISABLE;
336 	ICH_SET_REG(sc->bm_reg, bmval);
337 	ICH_SET_REG(sc->ctrl_reg, old_val | req_val);
338 	ICH_SET_REG(sc->bm_reg, bmval & ~ICHSS_BM_DISABLE);
339 
340 	/* Get the new value and re-enable interrupts. */
341 	new_val = ICH_GET_REG(sc->ctrl_reg);
342 	intr_restore(regs);
343 
344 	/* Check if the desired state was indeed selected. */
345 	if (req_val != (new_val & ICHSS_CTRL_BIT)) {
346 	    device_printf(sc->dev, "transition to %d failed\n", req_val);
347 	    return (ENXIO);
348 	}
349 
350 	/* Re-initialize our cycle counter if we don't know this new state. */
351 	if (sc->sets[req_val].freq == CPUFREQ_VAL_UNKNOWN) {
352 		cpu_est_clockrate(0, &rate);
353 		sc->sets[req_val].freq = rate / 1000000;
354 		DPRINT("ichss: set calibrated new rate of %d\n",
355 		    sc->sets[req_val].freq);
356 	}
357 
358 	return (0);
359 }
360 
361 static int
362 ichss_get(device_t dev, struct cf_setting *set)
363 {
364 	struct ichss_softc *sc;
365 	uint64_t rate;
366 	uint8_t state;
367 
368 	sc = device_get_softc(dev);
369 	state = ICH_GET_REG(sc->ctrl_reg) & ICHSS_CTRL_BIT;
370 
371 	/* If we haven't changed settings yet, estimate the current value. */
372 	if (sc->sets[state].freq == CPUFREQ_VAL_UNKNOWN) {
373 		cpu_est_clockrate(0, &rate);
374 		sc->sets[state].freq = rate / 1000000;
375 		DPRINT("ichss: get calibrated new rate of %d\n",
376 		    sc->sets[state].freq);
377 	}
378 	*set = sc->sets[state];
379 
380 	return (0);
381 }
382 
383 static int
384 ichss_type(device_t dev, int *type)
385 {
386 
387 	if (type == NULL)
388 		return (EINVAL);
389 
390 	*type = CPUFREQ_TYPE_ABSOLUTE;
391 	return (0);
392 }
393