xref: /freebsd/sys/powerpc/cpufreq/mpc85xx_jog.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
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/param.h>
28 #include <sys/systm.h>
29 #include <sys/bus.h>
30 #include <sys/cpu.h>
31 #include <sys/kernel.h>
32 #include <sys/module.h>
33 #include <sys/smp.h>
34 
35 #include <dev/ofw/ofw_bus.h>
36 #include <dev/ofw/ofw_bus_subr.h>
37 
38 #include <machine/cpu.h>
39 
40 #include <powerpc/mpc85xx/mpc85xx.h>
41 
42 #include "cpufreq_if.h"
43 
44 /* No worries about uint32_t math overflow in here, because the highest
45  * multiplier supported is 4, and the highest speed part is still well below
46  * 2GHz.
47  */
48 
49 #define	GUTS_PORPLLSR		(CCSRBAR_VA + 0xe0000)
50 #define	GUTS_PMJCR		(CCSRBAR_VA + 0xe007c)
51 #define	  PMJCR_RATIO_M		  0x3f
52 #define	  PMJCR_CORE_MULT(x,y)	  ((x) << (16 + ((y) * 8)))
53 #define	  PMJCR_GET_CORE_MULT(x,y)	  (((x) >> (16 + ((y) * 8))) & 0x3f)
54 #define	GUTS_POWMGTCSR		(CCSRBAR_VA + 0xe0080)
55 #define	  POWMGTCSR_JOG		  0x00200000
56 #define	  POWMGTCSR_INT_MASK	  0x00000f00
57 
58 #define	MHZ	1000000
59 
60 struct mpc85xx_jog_softc {
61 	device_t dev;
62 	int	cpu;
63 	int	low;
64 	int	high;
65 	int	min_freq;
66 };
67 
68 static struct ofw_compat_data *mpc85xx_jog_devcompat(void);
69 static void	mpc85xx_jog_identify(driver_t *driver, device_t parent);
70 static int	mpc85xx_jog_probe(device_t dev);
71 static int	mpc85xx_jog_attach(device_t dev);
72 static int	mpc85xx_jog_settings(device_t dev, struct cf_setting *sets, int *count);
73 static int	mpc85xx_jog_set(device_t dev, const struct cf_setting *set);
74 static int	mpc85xx_jog_get(device_t dev, struct cf_setting *set);
75 static int	mpc85xx_jog_type(device_t dev, int *type);
76 
77 static device_method_t mpc85xx_jog_methods[] = {
78 	/* Device interface */
79 	DEVMETHOD(device_identify,	mpc85xx_jog_identify),
80 	DEVMETHOD(device_probe,		mpc85xx_jog_probe),
81 	DEVMETHOD(device_attach,	mpc85xx_jog_attach),
82 
83 	/* cpufreq interface */
84 	DEVMETHOD(cpufreq_drv_set,	mpc85xx_jog_set),
85 	DEVMETHOD(cpufreq_drv_get,	mpc85xx_jog_get),
86 	DEVMETHOD(cpufreq_drv_type,	mpc85xx_jog_type),
87 	DEVMETHOD(cpufreq_drv_settings,	mpc85xx_jog_settings),
88 	{0, 0}
89 };
90 
91 static driver_t mpc85xx_jog_driver = {
92 	"jog",
93 	mpc85xx_jog_methods,
94 	sizeof(struct mpc85xx_jog_softc)
95 };
96 
97 DRIVER_MODULE(mpc85xx_jog, cpu, mpc85xx_jog_driver, 0, 0);
98 
99 struct mpc85xx_constraints {
100 	int threshold; /* Threshold frequency, in MHz, for setting CORE_SPD bit. */
101 	int min_mult;  /* Minimum PLL multiplier. */
102 };
103 
104 static struct mpc85xx_constraints mpc8536_constraints = {
105 	800,
106 	3
107 };
108 
109 static struct mpc85xx_constraints p1022_constraints = {
110 	500,
111 	2
112 };
113 
114 static struct ofw_compat_data jog_compat[] = {
115     {"fsl,mpc8536-guts", (uintptr_t)&mpc8536_constraints},
116     {"fsl,p1022-guts", (uintptr_t)&p1022_constraints},
117     {NULL, 0}
118 };
119 
120 static struct ofw_compat_data *
121 mpc85xx_jog_devcompat(void)
122 {
123 	phandle_t node;
124 	int i;
125 
126 	node = OF_finddevice("/soc");
127 	if (node == -1)
128 		return (NULL);
129 
130 	for (i = 0; jog_compat[i].ocd_str != NULL; i++)
131 		if (ofw_bus_find_compatible(node, jog_compat[i].ocd_str) > 0)
132 			break;
133 
134 	if (jog_compat[i].ocd_str == NULL)
135 		return (NULL);
136 
137 	return (&jog_compat[i]);
138 }
139 
140 static void
141 mpc85xx_jog_identify(driver_t *driver, device_t parent)
142 {
143 	struct ofw_compat_data *compat;
144 
145 	/* Make sure we're not being doubly invoked. */
146 	if (device_find_child(parent, "mpc85xx_jog", -1) != NULL)
147 		return;
148 
149 	compat = mpc85xx_jog_devcompat();
150 	if (compat == NULL)
151 		return;
152 
153 	/*
154 	 * We attach a child for every CPU since settings need to
155 	 * be performed on every CPU in the SMP case.
156 	 */
157 	if (BUS_ADD_CHILD(parent, 10, "jog", -1) == NULL)
158 		device_printf(parent, "add jog child failed\n");
159 }
160 
161 static int
162 mpc85xx_jog_probe(device_t dev)
163 {
164 	struct ofw_compat_data *compat;
165 
166 	compat = mpc85xx_jog_devcompat();
167 	if (compat == NULL || compat->ocd_str == NULL)
168 		return (ENXIO);
169 
170 	device_set_desc(dev, "Freescale CPU Jogger");
171 	return (0);
172 }
173 
174 static int
175 mpc85xx_jog_attach(device_t dev)
176 {
177 	struct ofw_compat_data *compat;
178 	struct mpc85xx_jog_softc *sc;
179 	struct mpc85xx_constraints *constraints;
180 	phandle_t cpu;
181 	uint32_t reg;
182 
183 	sc = device_get_softc(dev);
184 	sc->dev = dev;
185 
186 	compat = mpc85xx_jog_devcompat();
187 	constraints = (struct mpc85xx_constraints *)compat->ocd_data;
188 	cpu = ofw_bus_get_node(device_get_parent(dev));
189 
190 	if (cpu <= 0) {
191 		device_printf(dev,"No CPU device tree node!\n");
192 		return (ENXIO);
193 	}
194 
195 	OF_getencprop(cpu, "reg", &sc->cpu, sizeof(sc->cpu));
196 
197 	reg = ccsr_read4(GUTS_PORPLLSR);
198 
199 	/*
200 	 * Assume power-on PLL is the highest PLL config supported on the
201 	 * board.
202 	 */
203 	sc->high = PMJCR_GET_CORE_MULT(reg, sc->cpu);
204 	sc->min_freq = constraints->threshold;
205 	sc->low = constraints->min_mult;
206 
207 	cpufreq_register(dev);
208 	return (0);
209 }
210 
211 static int
212 mpc85xx_jog_settings(device_t dev, struct cf_setting *sets, int *count)
213 {
214 	struct mpc85xx_jog_softc *sc;
215 	uint32_t sysclk;
216 	int i;
217 
218 	sc = device_get_softc(dev);
219 	if (sets == NULL || count == NULL)
220 		return (EINVAL);
221 	if (*count < sc->high - 1)
222 		return (E2BIG);
223 
224 	sysclk = mpc85xx_get_system_clock();
225 	/* Return a list of valid settings for this driver. */
226 	memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * sc->high);
227 
228 	for (i = sc->high; i >= sc->low; --i) {
229 		sets[sc->high - i].freq = sysclk * i / MHZ;
230 		sets[sc->high - i].dev = dev;
231 		sets[sc->high - i].spec[0] = i;
232 	}
233 	*count = sc->high - sc->low + 1;
234 
235 	return (0);
236 }
237 
238 struct jog_rv_args {
239 	int cpu;
240 	int mult;
241 	int slow;
242 	volatile int inprogress;
243 };
244 
245 static void
246 mpc85xx_jog_set_int(void *arg)
247 {
248 	struct jog_rv_args *args = arg;
249 	uint32_t reg;
250 
251 	if (PCPU_GET(cpuid) == args->cpu) {
252 		reg = ccsr_read4(GUTS_PMJCR);
253 		reg &= ~PMJCR_CORE_MULT(PMJCR_RATIO_M, args->cpu);
254 		reg |= PMJCR_CORE_MULT(args->mult, args->cpu);
255 		if (args->slow)
256 			reg &= ~(1 << (12 + args->cpu));
257 		else
258 			reg |= (1 << (12 + args->cpu));
259 
260 		ccsr_write4(GUTS_PMJCR, reg);
261 
262 		reg = ccsr_read4(GUTS_POWMGTCSR);
263 		reg |= POWMGTCSR_JOG | POWMGTCSR_INT_MASK;
264 		ccsr_write4(GUTS_POWMGTCSR, reg);
265 
266 		/* Wait for completion */
267 		do {
268 			DELAY(100);
269 			reg = ccsr_read4(GUTS_POWMGTCSR);
270 		} while (reg & POWMGTCSR_JOG);
271 
272 		reg = ccsr_read4(GUTS_POWMGTCSR);
273 		ccsr_write4(GUTS_POWMGTCSR, reg & ~POWMGTCSR_INT_MASK);
274 		ccsr_read4(GUTS_POWMGTCSR);
275 
276 		args->inprogress = 0;
277 	} else {
278 		while (args->inprogress)
279 			cpu_spinwait();
280 	}
281 }
282 
283 static int
284 mpc85xx_jog_set(device_t dev, const struct cf_setting *set)
285 {
286 	struct mpc85xx_jog_softc *sc;
287 	struct jog_rv_args args;
288 
289 	if (set == NULL)
290 		return (EINVAL);
291 
292 	sc = device_get_softc(dev);
293 
294 	args.slow = (set->freq <= sc->min_freq);
295 	args.mult = set->spec[0];
296 	args.cpu = PCPU_GET(cpuid);
297 	args.inprogress = 1;
298 	smp_rendezvous(smp_no_rendezvous_barrier, mpc85xx_jog_set_int,
299 	    smp_no_rendezvous_barrier, &args);
300 
301 	return (0);
302 }
303 
304 static int
305 mpc85xx_jog_get(device_t dev, struct cf_setting *set)
306 {
307 	struct mpc85xx_jog_softc *sc;
308 	uint32_t pmjcr;
309 	uint32_t freq;
310 
311 	if (set == NULL)
312 		return (EINVAL);
313 
314 	sc = device_get_softc(dev);
315 	memset(set, CPUFREQ_VAL_UNKNOWN, sizeof(*set));
316 
317 	pmjcr = ccsr_read4(GUTS_PORPLLSR);
318 	freq = PMJCR_GET_CORE_MULT(pmjcr, sc->cpu);
319 	freq *= mpc85xx_get_system_clock();
320 	freq /= MHZ;
321 
322 	set->freq = freq;
323 	set->dev = dev;
324 
325 	return (0);
326 }
327 
328 static int
329 mpc85xx_jog_type(device_t dev, int *type)
330 {
331 
332 	if (type == NULL)
333 		return (EINVAL);
334 
335 	*type = CPUFREQ_TYPE_ABSOLUTE;
336 	return (0);
337 }
338