xref: /freebsd/sys/powerpc/cpufreq/mpc85xx_jog.c (revision 2b8331622f0b212cf3bb4fc4914a501e5321d506)
1 /*-
2  * Copyright (c) 2017 Justin Hibbits
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 ``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
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/cpu.h>
34 #include <sys/kernel.h>
35 #include <sys/module.h>
36 #include <sys/smp.h>
37 
38 #include <dev/ofw/ofw_bus.h>
39 #include <dev/ofw/ofw_bus_subr.h>
40 
41 #include <machine/cpu.h>
42 
43 #include <powerpc/mpc85xx/mpc85xx.h>
44 
45 #include "cpufreq_if.h"
46 
47 /* No worries about uint32_t math overflow in here, because the highest
48  * multiplier supported is 4, and the highest speed part is still well below
49  * 2GHz.
50  */
51 
52 #define	GUTS_PORPLLSR		(CCSRBAR_VA + 0xe0000)
53 #define	GUTS_PMJCR		(CCSRBAR_VA + 0xe007c)
54 #define	  PMJCR_RATIO_M		  0x3f
55 #define	  PMJCR_CORE_MULT(x,y)	  ((x) << (16 + ((y) * 8)))
56 #define	  PMJCR_GET_CORE_MULT(x,y)	  (((x) >> (16 + ((y) * 8))) & 0x3f)
57 #define	GUTS_POWMGTCSR		(CCSRBAR_VA + 0xe0080)
58 #define	  POWMGTCSR_JOG		  0x00200000
59 #define	  POWMGTCSR_INT_MASK	  0x00000f00
60 
61 #define	MHZ	1000000
62 
63 struct mpc85xx_jog_softc {
64 	device_t dev;
65 	int	cpu;
66 	int	low;
67 	int	high;
68 	int	min_freq;
69 };
70 
71 static struct ofw_compat_data *mpc85xx_jog_devcompat(void);
72 static void	mpc85xx_jog_identify(driver_t *driver, device_t parent);
73 static int	mpc85xx_jog_probe(device_t dev);
74 static int	mpc85xx_jog_attach(device_t dev);
75 static int	mpc85xx_jog_settings(device_t dev, struct cf_setting *sets, int *count);
76 static int	mpc85xx_jog_set(device_t dev, const struct cf_setting *set);
77 static int	mpc85xx_jog_get(device_t dev, struct cf_setting *set);
78 static int	mpc85xx_jog_type(device_t dev, int *type);
79 
80 static device_method_t mpc85xx_jog_methods[] = {
81 	/* Device interface */
82 	DEVMETHOD(device_identify,	mpc85xx_jog_identify),
83 	DEVMETHOD(device_probe,		mpc85xx_jog_probe),
84 	DEVMETHOD(device_attach,	mpc85xx_jog_attach),
85 
86 	/* cpufreq interface */
87 	DEVMETHOD(cpufreq_drv_set,	mpc85xx_jog_set),
88 	DEVMETHOD(cpufreq_drv_get,	mpc85xx_jog_get),
89 	DEVMETHOD(cpufreq_drv_type,	mpc85xx_jog_type),
90 	DEVMETHOD(cpufreq_drv_settings,	mpc85xx_jog_settings),
91 	{0, 0}
92 };
93 
94 static driver_t mpc85xx_jog_driver = {
95 	"jog",
96 	mpc85xx_jog_methods,
97 	sizeof(struct mpc85xx_jog_softc)
98 };
99 
100 DRIVER_MODULE(mpc85xx_jog, cpu, mpc85xx_jog_driver, 0, 0);
101 
102 struct mpc85xx_constraints {
103 	int threshold; /* Threshold frequency, in MHz, for setting CORE_SPD bit. */
104 	int min_mult;  /* Minimum PLL multiplier. */
105 };
106 
107 static struct mpc85xx_constraints mpc8536_constraints = {
108 	800,
109 	3
110 };
111 
112 static struct mpc85xx_constraints p1022_constraints = {
113 	500,
114 	2
115 };
116 
117 static struct ofw_compat_data jog_compat[] = {
118     {"fsl,mpc8536-guts", (uintptr_t)&mpc8536_constraints},
119     {"fsl,p1022-guts", (uintptr_t)&p1022_constraints},
120     {NULL, 0}
121 };
122 
123 static struct ofw_compat_data *
124 mpc85xx_jog_devcompat()
125 {
126 	phandle_t node;
127 	int i;
128 
129 	node = OF_finddevice("/soc");
130 	if (node == -1)
131 		return (NULL);
132 
133 	for (i = 0; jog_compat[i].ocd_str != NULL; i++)
134 		if (ofw_bus_find_compatible(node, jog_compat[i].ocd_str) > 0)
135 			break;
136 
137 	if (jog_compat[i].ocd_str == NULL)
138 		return (NULL);
139 
140 	return (&jog_compat[i]);
141 }
142 
143 static void
144 mpc85xx_jog_identify(driver_t *driver, device_t parent)
145 {
146 	struct ofw_compat_data *compat;
147 
148 	/* Make sure we're not being doubly invoked. */
149 	if (device_find_child(parent, "mpc85xx_jog", -1) != NULL)
150 		return;
151 
152 	compat = mpc85xx_jog_devcompat();
153 	if (compat == NULL)
154 		return;
155 
156 	/*
157 	 * We attach a child for every CPU since settings need to
158 	 * be performed on every CPU in the SMP case.
159 	 */
160 	if (BUS_ADD_CHILD(parent, 10, "jog", -1) == NULL)
161 		device_printf(parent, "add jog child failed\n");
162 }
163 
164 static int
165 mpc85xx_jog_probe(device_t dev)
166 {
167 	struct ofw_compat_data *compat;
168 
169 	compat = mpc85xx_jog_devcompat();
170 	if (compat == NULL || compat->ocd_str == NULL)
171 		return (ENXIO);
172 
173 	device_set_desc(dev, "Freescale CPU Jogger");
174 	return (0);
175 }
176 
177 static int
178 mpc85xx_jog_attach(device_t dev)
179 {
180 	struct ofw_compat_data *compat;
181 	struct mpc85xx_jog_softc *sc;
182 	struct mpc85xx_constraints *constraints;
183 	phandle_t cpu;
184 	uint32_t reg;
185 
186 	sc = device_get_softc(dev);
187 	sc->dev = dev;
188 
189 	compat = mpc85xx_jog_devcompat();
190 	constraints = (struct mpc85xx_constraints *)compat->ocd_data;
191 	cpu = ofw_bus_get_node(device_get_parent(dev));
192 
193 	if (cpu <= 0) {
194 		device_printf(dev,"No CPU device tree node!\n");
195 		return (ENXIO);
196 	}
197 
198 	OF_getencprop(cpu, "reg", &sc->cpu, sizeof(sc->cpu));
199 
200 	reg = ccsr_read4(GUTS_PORPLLSR);
201 
202 	/*
203 	 * Assume power-on PLL is the highest PLL config supported on the
204 	 * board.
205 	 */
206 	sc->high = PMJCR_GET_CORE_MULT(reg, sc->cpu);
207 	sc->min_freq = constraints->threshold;
208 	sc->low = constraints->min_mult;
209 
210 	cpufreq_register(dev);
211 	return (0);
212 }
213 
214 static int
215 mpc85xx_jog_settings(device_t dev, struct cf_setting *sets, int *count)
216 {
217 	struct mpc85xx_jog_softc *sc;
218 	uint32_t sysclk;
219 	int i;
220 
221 	sc = device_get_softc(dev);
222 	if (sets == NULL || count == NULL)
223 		return (EINVAL);
224 	if (*count < sc->high - 1)
225 		return (E2BIG);
226 
227 	sysclk = mpc85xx_get_system_clock();
228 	/* Return a list of valid settings for this driver. */
229 	memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * sc->high);
230 
231 	for (i = sc->high; i >= sc->low; --i) {
232 		sets[sc->high - i].freq = sysclk * i / MHZ;
233 		sets[sc->high - i].dev = dev;
234 		sets[sc->high - i].spec[0] = i;
235 	}
236 	*count = sc->high - sc->low + 1;
237 
238 	return (0);
239 }
240 
241 struct jog_rv_args {
242 	int cpu;
243 	int mult;
244 	int slow;
245 	volatile int inprogress;
246 };
247 
248 static void
249 mpc85xx_jog_set_int(void *arg)
250 {
251 	struct jog_rv_args *args = arg;
252 	uint32_t reg;
253 
254 	if (PCPU_GET(cpuid) == args->cpu) {
255 		reg = ccsr_read4(GUTS_PMJCR);
256 		reg &= ~PMJCR_CORE_MULT(PMJCR_RATIO_M, args->cpu);
257 		reg |= PMJCR_CORE_MULT(args->mult, args->cpu);
258 		if (args->slow)
259 			reg &= ~(1 << (12 + args->cpu));
260 		else
261 			reg |= (1 << (12 + args->cpu));
262 
263 		ccsr_write4(GUTS_PMJCR, reg);
264 
265 		reg = ccsr_read4(GUTS_POWMGTCSR);
266 		reg |= POWMGTCSR_JOG | POWMGTCSR_INT_MASK;
267 		ccsr_write4(GUTS_POWMGTCSR, reg);
268 
269 		/* Wait for completion */
270 		do {
271 			DELAY(100);
272 			reg = ccsr_read4(GUTS_POWMGTCSR);
273 		} while (reg & POWMGTCSR_JOG);
274 
275 		reg = ccsr_read4(GUTS_POWMGTCSR);
276 		ccsr_write4(GUTS_POWMGTCSR, reg & ~POWMGTCSR_INT_MASK);
277 		ccsr_read4(GUTS_POWMGTCSR);
278 
279 		args->inprogress = 0;
280 	} else {
281 		while (args->inprogress)
282 			cpu_spinwait();
283 	}
284 }
285 
286 static int
287 mpc85xx_jog_set(device_t dev, const struct cf_setting *set)
288 {
289 	struct mpc85xx_jog_softc *sc;
290 	struct jog_rv_args args;
291 
292 	if (set == NULL)
293 		return (EINVAL);
294 
295 	sc = device_get_softc(dev);
296 
297 	args.slow = (set->freq <= sc->min_freq);
298 	args.mult = set->spec[0];
299 	args.cpu = PCPU_GET(cpuid);
300 	args.inprogress = 1;
301 	smp_rendezvous(smp_no_rendezvous_barrier, mpc85xx_jog_set_int,
302 	    smp_no_rendezvous_barrier, &args);
303 
304 	return (0);
305 }
306 
307 static int
308 mpc85xx_jog_get(device_t dev, struct cf_setting *set)
309 {
310 	struct mpc85xx_jog_softc *sc;
311 	uint32_t pmjcr;
312 	uint32_t freq;
313 
314 	if (set == NULL)
315 		return (EINVAL);
316 
317 	sc = device_get_softc(dev);
318 	memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set));
319 
320 	pmjcr = ccsr_read4(GUTS_PORPLLSR);
321 	freq = PMJCR_GET_CORE_MULT(pmjcr, sc->cpu);
322 	freq *= mpc85xx_get_system_clock();
323 	freq /= MHZ;
324 
325 	set->freq = freq;
326 	set->dev = dev;
327 
328 	return (0);
329 }
330 
331 static int
332 mpc85xx_jog_type(device_t dev, int *type)
333 {
334 
335 	if (type == NULL)
336 		return (EINVAL);
337 
338 	*type = CPUFREQ_TYPE_ABSOLUTE;
339 	return (0);
340 }
341