2 * Copyright (c) 2009 Nathan Whitehorn
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
19 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
21 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
22 * 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
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/module.h>
37 #include <dev/ofw/ofw_bus.h>
39 #include "cpufreq_if.h"
47 static void pcr_identify(driver_t *driver, device_t parent);
48 static int pcr_probe(device_t dev);
49 static int pcr_attach(device_t dev);
50 static int pcr_settings(device_t dev, struct cf_setting *sets, int *count);
51 static int pcr_set(device_t dev, const struct cf_setting *set);
52 static int pcr_get(device_t dev, struct cf_setting *set);
53 static int pcr_type(device_t dev, int *type);
55 static device_method_t pcr_methods[] = {
56 /* Device interface */
57 DEVMETHOD(device_identify, pcr_identify),
58 DEVMETHOD(device_probe, pcr_probe),
59 DEVMETHOD(device_attach, pcr_attach),
61 /* cpufreq interface */
62 DEVMETHOD(cpufreq_drv_set, pcr_set),
63 DEVMETHOD(cpufreq_drv_get, pcr_get),
64 DEVMETHOD(cpufreq_drv_type, pcr_type),
65 DEVMETHOD(cpufreq_drv_settings, pcr_settings),
70 static driver_t pcr_driver = {
73 sizeof(struct pcr_softc)
76 static devclass_t pcr_devclass;
77 DRIVER_MODULE(pcr, cpu, pcr_driver, pcr_devclass, 0, 0);
83 #define PCR_TO_FREQ(a) ((a >> 17) & 3)
87 #define PCR_QUARTER 2 /* Only on 970MP */
89 #define PSR_RECEIVED (1ULL << 61)
90 #define PSR_COMPLETED (1ULL << 61)
96 #define SCOM_PCR 0x0aa00100 /* Power Control Register */
97 #define SCOM_PCR_BIT 0x80000000 /* Data bit for PCR */
98 #define SCOM_PSR 0x40800100 /* Power Status Register */
104 #define SCOMC_READ 0x00008000
105 #define SCOMC_WRITE 0x00000000
108 write_scom(register_t address, uint64_t value)
111 #ifndef __powerpc64__
112 register_t hi, lo, scratch;
116 mtmsr(msr & ~PSL_EE); isync();
119 mtspr(SPR_SCOMD, value);
121 hi = (value >> 32) & 0xffffffff;
122 lo = value & 0xffffffff;
123 mtspr64(SPR_SCOMD, hi, lo, scratch);
126 mtspr(SPR_SCOMC, address | SCOMC_WRITE);
133 read_scom(register_t address)
139 mtmsr(msr & ~PSL_EE); isync();
141 mtspr(SPR_SCOMC, address | SCOMC_READ);
144 __asm __volatile ("mfspr %0,%1;"
145 " mr %0+1, %0; srdi %0,%0,32" : "=r" (ret) : "K" (SPR_SCOMD));
147 (void)mfspr(SPR_SCOMC); /* Complete transcation */
155 pcr_identify(driver_t *driver, device_t parent)
158 vers = mfpvr() >> 16;
160 /* Check for an IBM 970-class CPU */
170 /* Make sure we're not being doubly invoked. */
171 if (device_find_child(parent, "pcr", -1) != NULL)
175 * We attach a child for every CPU since settings need to
176 * be performed on every CPU in the SMP case.
178 if (BUS_ADD_CHILD(parent, 10, "pcr", -1) == NULL)
179 device_printf(parent, "add pcr child failed\n");
183 pcr_probe(device_t dev)
185 if (resource_disabled("pcr", 0))
188 device_set_desc(dev, "PPC 970 Power Control Register");
193 pcr_attach(device_t dev)
195 struct pcr_softc *sc;
200 sc = device_get_softc(dev);
203 cpu = ofw_bus_get_node(device_get_parent(dev));
206 device_printf(dev,"No CPU device tree node!\n");
210 if (OF_getproplen(cpu, "power-mode-data") <= 0) {
211 /* Use the first CPU's node */
212 cpu = OF_child(OF_parent(cpu));
216 * Collect the PCR values for each mode from the device tree.
217 * These include bus timing information, and so cannot be
220 sc->nmodes = OF_getproplen(cpu, "power-mode-data");
221 if (sc->nmodes <= 0 || sc->nmodes > sizeof(sc->pcr_vals)) {
222 device_printf(dev,"No power mode data in device tree!\n");
225 OF_getprop(cpu, "power-mode-data", modes, sc->nmodes);
226 sc->nmodes /= sizeof(modes[0]);
229 for (i = 0; i < sc->nmodes; i++)
230 sc->pcr_vals[PCR_TO_FREQ(modes[i])] = modes[i];
232 cpufreq_register(dev);
237 pcr_settings(device_t dev, struct cf_setting *sets, int *count)
239 struct pcr_softc *sc;
241 sc = device_get_softc(dev);
242 if (sets == NULL || count == NULL)
244 if (*count < sc->nmodes)
247 /* Return a list of valid settings for this driver. */
248 memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * sc->nmodes);
250 sets[0].freq = 10000; sets[0].dev = dev;
251 sets[1].freq = 5000; sets[1].dev = dev;
253 sets[2].freq = 2500; sets[2].dev = dev;
260 pcr_set(device_t dev, const struct cf_setting *set)
262 struct pcr_softc *sc;
268 sc = device_get_softc(dev);
270 /* Construct the new PCR */
274 if (set->freq == 10000)
275 pcr |= sc->pcr_vals[0];
276 else if (set->freq == 5000)
277 pcr |= sc->pcr_vals[1];
278 else if (set->freq == 2500)
279 pcr |= sc->pcr_vals[2];
282 mtmsr(msr & ~PSL_EE); isync();
284 /* 970MP requires PCR and PCRH to be cleared first */
286 write_scom(SCOM_PCR,0); /* Clear PCRH */
287 write_scom(SCOM_PCR,SCOM_PCR_BIT); /* Clear PCR */
291 write_scom(SCOM_PCR, pcr);
293 /* Wait for completion */
297 psr = read_scom(SCOM_PSR);
298 } while ((psr & PSR_RECEIVED) && !(psr & PSR_COMPLETED));
306 pcr_get(device_t dev, struct cf_setting *set)
313 memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set));
315 psr = read_scom(SCOM_PSR);
317 /* We want bits 6 and 7 */
318 psr = (psr >> 56) & 3;
323 else if (psr == PCR_QUARTER)
332 pcr_type(device_t dev, int *type)
338 *type = CPUFREQ_TYPE_RELATIVE;