xref: /freebsd/sys/dev/cpufreq/ichss.c (revision 3e102307b7637eaab1e213740399e9ce50ef3c1b)
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_82815_MC	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 	DEVMETHOD_END
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 	ich_device = pci_find_bsf(0, 0x1f, 0);
160 	if (ich_device == NULL ||
161 	    pci_get_vendor(ich_device) != PCI_VENDOR_INTEL ||
162 	    (pci_get_device(ich_device) != PCI_DEV_82801BA &&
163 	    pci_get_device(ich_device) != PCI_DEV_82801CA &&
164 	    pci_get_device(ich_device) != PCI_DEV_82801DB))
165 		return;
166 
167 	/*
168 	 * Certain systems with ICH2 and an Intel 82815_MC host bridge
169 	 * where the host bridge's revision is < 5 lockup if SpeedStep
170 	 * is used.
171 	 */
172 	if (pci_get_device(ich_device) == PCI_DEV_82801BA) {
173 		device_t hostb;
174 
175 		hostb = pci_find_bsf(0, 0, 0);
176 		if (hostb != NULL &&
177 		    pci_get_vendor(hostb) == PCI_VENDOR_INTEL &&
178 		    pci_get_device(hostb) == PCI_DEV_82815_MC &&
179 		    pci_get_revid(hostb) < 5)
180 			return;
181 	}
182 
183 	/* Find the PMBASE register from our PCI config header. */
184 	pmbase = pci_read_config(ich_device, ICHSS_PMBASE_OFFSET,
185 	    sizeof(pmbase));
186 	if ((pmbase & ICHSS_IO_REG) == 0) {
187 		printf("ichss: invalid PMBASE memory type\n");
188 		return;
189 	}
190 	pmbase &= ICHSS_PMBASE_MASK;
191 	if (pmbase == 0) {
192 		printf("ichss: invalid zero PMBASE address\n");
193 		return;
194 	}
195 	DPRINT("ichss: PMBASE is %#x\n", pmbase);
196 
197 	child = BUS_ADD_CHILD(parent, 20, "ichss", 0);
198 	if (child == NULL) {
199 		device_printf(parent, "add SpeedStep child failed\n");
200 		return;
201 	}
202 
203 	/* Add the bus master arbitration and control registers. */
204 	bus_set_resource(child, SYS_RES_IOPORT, 0, pmbase + ICHSS_BM_OFFSET,
205 	    1);
206 	bus_set_resource(child, SYS_RES_IOPORT, 1, pmbase + ICHSS_CTRL_OFFSET,
207 	    1);
208 }
209 
210 static int
211 ichss_probe(device_t dev)
212 {
213 	device_t est_dev, perf_dev;
214 	int error, type;
215 
216 	/*
217 	 * If the ACPI perf driver has attached and is not just offering
218 	 * info, let it manage things.  Also, if Enhanced SpeedStep is
219 	 * available, don't attach.
220 	 */
221 	perf_dev = device_find_child(device_get_parent(dev), "acpi_perf", -1);
222 	if (perf_dev && device_is_attached(perf_dev)) {
223 		error = CPUFREQ_DRV_TYPE(perf_dev, &type);
224 		if (error == 0 && (type & CPUFREQ_FLAG_INFO_ONLY) == 0)
225 			return (ENXIO);
226 	}
227 	est_dev = device_find_child(device_get_parent(dev), "est", -1);
228 	if (est_dev && device_is_attached(est_dev))
229 		return (ENXIO);
230 
231 	device_set_desc(dev, "SpeedStep ICH");
232 	return (-1000);
233 }
234 
235 static int
236 ichss_attach(device_t dev)
237 {
238 	struct ichss_softc *sc;
239 	uint16_t ss_en;
240 
241 	sc = device_get_softc(dev);
242 	sc->dev = dev;
243 
244 	sc->bm_rid = 0;
245 	sc->bm_reg = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &sc->bm_rid,
246 	    RF_ACTIVE);
247 	if (sc->bm_reg == NULL) {
248 		device_printf(dev, "failed to alloc BM arb register\n");
249 		return (ENXIO);
250 	}
251 	sc->ctrl_rid = 1;
252 	sc->ctrl_reg = bus_alloc_resource_any(dev, SYS_RES_IOPORT,
253 	    &sc->ctrl_rid, RF_ACTIVE);
254 	if (sc->ctrl_reg == NULL) {
255 		device_printf(dev, "failed to alloc control register\n");
256 		bus_release_resource(dev, SYS_RES_IOPORT, sc->bm_rid,
257 		    sc->bm_reg);
258 		return (ENXIO);
259 	}
260 
261 	/* Activate SpeedStep control if not already enabled. */
262 	ss_en = pci_read_config(ich_device, ICHSS_PMCFG_OFFSET, sizeof(ss_en));
263 	if ((ss_en & ICHSS_ENABLE) == 0) {
264 		device_printf(dev, "enabling SpeedStep support\n");
265 		pci_write_config(ich_device, ICHSS_PMCFG_OFFSET,
266 		    ss_en | ICHSS_ENABLE, sizeof(ss_en));
267 	}
268 
269 	/* Setup some defaults for our exported settings. */
270 	sc->sets[0].freq = CPUFREQ_VAL_UNKNOWN;
271 	sc->sets[0].volts = CPUFREQ_VAL_UNKNOWN;
272 	sc->sets[0].power = CPUFREQ_VAL_UNKNOWN;
273 	sc->sets[0].lat = 1000;
274 	sc->sets[0].dev = dev;
275 	sc->sets[1] = sc->sets[0];
276 	cpufreq_register(dev);
277 
278 	return (0);
279 }
280 
281 static int
282 ichss_detach(device_t dev)
283 {
284 	/* TODO: teardown BM and CTRL registers. */
285 	return (ENXIO);
286 }
287 
288 static int
289 ichss_settings(device_t dev, struct cf_setting *sets, int *count)
290 {
291 	struct ichss_softc *sc;
292 	struct cf_setting set;
293 	int first, i;
294 
295 	if (sets == NULL || count == NULL)
296 		return (EINVAL);
297 	if (*count < 2) {
298 		*count = 2;
299 		return (E2BIG);
300 	}
301 	sc = device_get_softc(dev);
302 
303 	/*
304 	 * Estimate frequencies for both levels, temporarily switching to
305 	 * the other one if we haven't calibrated it yet.
306 	 */
307 	ichss_get(dev, &set);
308 	for (i = 0; i < 2; i++) {
309 		if (sc->sets[i].freq == CPUFREQ_VAL_UNKNOWN) {
310 			first = (i == 0) ? 1 : 0;
311 			ichss_set(dev, &sc->sets[i]);
312 			ichss_set(dev, &sc->sets[first]);
313 		}
314 	}
315 
316 	bcopy(sc->sets, sets, sizeof(sc->sets));
317 	*count = 2;
318 
319 	return (0);
320 }
321 
322 static int
323 ichss_set(device_t dev, const struct cf_setting *set)
324 {
325 	struct ichss_softc *sc;
326 	uint8_t bmval, new_val, old_val, req_val;
327 	uint64_t rate;
328 	register_t regs;
329 
330 	/* Look up appropriate bit value based on frequency. */
331 	sc = device_get_softc(dev);
332 	if (CPUFREQ_CMP(set->freq, sc->sets[0].freq))
333 		req_val = 0;
334 	else if (CPUFREQ_CMP(set->freq, sc->sets[1].freq))
335 		req_val = ICHSS_CTRL_BIT;
336 	else
337 		return (EINVAL);
338 	DPRINT("ichss: requested setting %d\n", req_val);
339 
340 	/* Disable interrupts and get the other register contents. */
341 	regs = intr_disable();
342 	old_val = ICH_GET_REG(sc->ctrl_reg) & ~ICHSS_CTRL_BIT;
343 
344 	/*
345 	 * Disable bus master arbitration, write the new value to the control
346 	 * register, and then re-enable bus master arbitration.
347 	 */
348 	bmval = ICH_GET_REG(sc->bm_reg) | ICHSS_BM_DISABLE;
349 	ICH_SET_REG(sc->bm_reg, bmval);
350 	ICH_SET_REG(sc->ctrl_reg, old_val | req_val);
351 	ICH_SET_REG(sc->bm_reg, bmval & ~ICHSS_BM_DISABLE);
352 
353 	/* Get the new value and re-enable interrupts. */
354 	new_val = ICH_GET_REG(sc->ctrl_reg);
355 	intr_restore(regs);
356 
357 	/* Check if the desired state was indeed selected. */
358 	if (req_val != (new_val & ICHSS_CTRL_BIT)) {
359 	    device_printf(sc->dev, "transition to %d failed\n", req_val);
360 	    return (ENXIO);
361 	}
362 
363 	/* Re-initialize our cycle counter if we don't know this new state. */
364 	if (sc->sets[req_val].freq == CPUFREQ_VAL_UNKNOWN) {
365 		cpu_est_clockrate(0, &rate);
366 		sc->sets[req_val].freq = rate / 1000000;
367 		DPRINT("ichss: set calibrated new rate of %d\n",
368 		    sc->sets[req_val].freq);
369 	}
370 
371 	return (0);
372 }
373 
374 static int
375 ichss_get(device_t dev, struct cf_setting *set)
376 {
377 	struct ichss_softc *sc;
378 	uint64_t rate;
379 	uint8_t state;
380 
381 	sc = device_get_softc(dev);
382 	state = ICH_GET_REG(sc->ctrl_reg) & ICHSS_CTRL_BIT;
383 
384 	/* If we haven't changed settings yet, estimate the current value. */
385 	if (sc->sets[state].freq == CPUFREQ_VAL_UNKNOWN) {
386 		cpu_est_clockrate(0, &rate);
387 		sc->sets[state].freq = rate / 1000000;
388 		DPRINT("ichss: get calibrated new rate of %d\n",
389 		    sc->sets[state].freq);
390 	}
391 	*set = sc->sets[state];
392 
393 	return (0);
394 }
395 
396 static int
397 ichss_type(device_t dev, int *type)
398 {
399 
400 	if (type == NULL)
401 		return (EINVAL);
402 
403 	*type = CPUFREQ_TYPE_ABSOLUTE;
404 	return (0);
405 }
406