1 /*
2  *  (C) 2004-2009  Dominik Brodowski <linux@dominikbrodowski.de>
3  *
4  *  Licensed under the terms of the GNU GPL License version 2.
5  */
6 
7 
8 #include <unistd.h>
9 #include <stdio.h>
10 #include <errno.h>
11 #include <stdlib.h>
12 #include <limits.h>
13 #include <string.h>
14 #include <ctype.h>
15 
16 #include <getopt.h>
17 
18 #include "cpufreq.h"
19 #include "helpers/helpers.h"
20 
21 #define NORM_FREQ_LEN 32
22 
23 static struct option set_opts[] = {
24 	{ .name = "min",	.has_arg = required_argument,	.flag = NULL,	.val = 'd'},
25 	{ .name = "max",	.has_arg = required_argument,	.flag = NULL,	.val = 'u'},
26 	{ .name = "governor",	.has_arg = required_argument,	.flag = NULL,	.val = 'g'},
27 	{ .name = "freq",	.has_arg = required_argument,	.flag = NULL,	.val = 'f'},
28 	{ .name = "related",	.has_arg = no_argument,		.flag = NULL,	.val='r'},
29 	{ },
30 };
31 
32 static void print_error(void)
33 {
34 	printf(_("Error setting new values. Common errors:\n"
35 			"- Do you have proper administration rights? (super-user?)\n"
36 			"- Is the governor you requested available and modprobed?\n"
37 			"- Trying to set an invalid policy?\n"
38 			"- Trying to set a specific frequency, but userspace governor is not available,\n"
39 			"   for example because of hardware which cannot be set to a specific frequency\n"
40 			"   or because the userspace governor isn't loaded?\n"));
41 };
42 
43 struct freq_units {
44 	char		*str_unit;
45 	int		power_of_ten;
46 };
47 
48 const struct freq_units def_units[] = {
49 	{"hz", -3},
50 	{"khz", 0}, /* default */
51 	{"mhz", 3},
52 	{"ghz", 6},
53 	{"thz", 9},
54 	{NULL, 0}
55 };
56 
57 static void print_unknown_arg(void)
58 {
59 	printf(_("invalid or unknown argument\n"));
60 }
61 
62 static unsigned long string_to_frequency(const char *str)
63 {
64 	char normalized[NORM_FREQ_LEN];
65 	const struct freq_units *unit;
66 	const char *scan;
67 	char *end;
68 	unsigned long freq;
69 	int power = 0, match_count = 0, i, cp, pad;
70 
71 	while (*str == '0')
72 		str++;
73 
74 	for (scan = str; isdigit(*scan) || *scan == '.'; scan++) {
75 		if (*scan == '.' && match_count == 0)
76 			match_count = 1;
77 		else if (*scan == '.' && match_count == 1)
78 			return 0;
79 	}
80 
81 	if (*scan) {
82 		match_count = 0;
83 		for (unit = def_units; unit->str_unit; unit++) {
84 			for (i = 0;
85 			     scan[i] && tolower(scan[i]) == unit->str_unit[i];
86 			     ++i)
87 				continue;
88 			if (scan[i])
89 				continue;
90 			match_count++;
91 			power = unit->power_of_ten;
92 		}
93 		if (match_count != 1)
94 			return 0;
95 	}
96 
97 	/* count the number of digits to be copied */
98 	for (cp = 0; isdigit(str[cp]); cp++)
99 		continue;
100 
101 	if (str[cp] == '.') {
102 		while (power > -1 && isdigit(str[cp+1]))
103 			cp++, power--;
104 	}
105 	if (power >= -1)	/* not enough => pad */
106 		pad = power + 1;
107 	else			/* to much => strip */
108 		pad = 0, cp += power + 1;
109 	/* check bounds */
110 	if (cp <= 0 || cp + pad > NORM_FREQ_LEN - 1)
111 		return 0;
112 
113 	/* copy digits */
114 	for (i = 0; i < cp; i++, str++) {
115 		if (*str == '.')
116 			str++;
117 		normalized[i] = *str;
118 	}
119 	/* and pad */
120 	for (; i < cp + pad; i++)
121 		normalized[i] = '0';
122 
123 	/* round up, down ? */
124 	match_count = (normalized[i-1] >= '5');
125 	/* and drop the decimal part */
126 	normalized[i-1] = 0; /* cp > 0 && pad >= 0 ==> i > 0 */
127 
128 	/* final conversion (and applying rounding) */
129 	errno = 0;
130 	freq = strtoul(normalized, &end, 10);
131 	if (errno)
132 		return 0;
133 	else {
134 		if (match_count && freq != ULONG_MAX)
135 			freq++;
136 		return freq;
137 	}
138 }
139 
140 static int do_new_policy(unsigned int cpu, struct cpufreq_policy *new_pol)
141 {
142 	struct cpufreq_policy *cur_pol = cpufreq_get_policy(cpu);
143 	int ret;
144 
145 	if (!cur_pol) {
146 		printf(_("wrong, unknown or unhandled CPU?\n"));
147 		return -EINVAL;
148 	}
149 
150 	if (!new_pol->min)
151 		new_pol->min = cur_pol->min;
152 
153 	if (!new_pol->max)
154 		new_pol->max = cur_pol->max;
155 
156 	if (!new_pol->governor)
157 		new_pol->governor = cur_pol->governor;
158 
159 	ret = cpufreq_set_policy(cpu, new_pol);
160 
161 	cpufreq_put_policy(cur_pol);
162 
163 	return ret;
164 }
165 
166 
167 static int do_one_cpu(unsigned int cpu, struct cpufreq_policy *new_pol,
168 		unsigned long freq, unsigned int pc)
169 {
170 	switch (pc) {
171 	case 0:
172 		return cpufreq_set_frequency(cpu, freq);
173 
174 	case 1:
175 		/* if only one value of a policy is to be changed, we can
176 		 * use a "fast path".
177 		 */
178 		if (new_pol->min)
179 			return cpufreq_modify_policy_min(cpu, new_pol->min);
180 		else if (new_pol->max)
181 			return cpufreq_modify_policy_max(cpu, new_pol->max);
182 		else if (new_pol->governor)
183 			return cpufreq_modify_policy_governor(cpu,
184 							new_pol->governor);
185 
186 	default:
187 		/* slow path */
188 		return do_new_policy(cpu, new_pol);
189 	}
190 }
191 
192 int cmd_freq_set(int argc, char **argv)
193 {
194 	extern char *optarg;
195 	extern int optind, opterr, optopt;
196 	int ret = 0, cont = 1;
197 	int double_parm = 0, related = 0, policychange = 0;
198 	unsigned long freq = 0;
199 	char gov[20];
200 	unsigned int cpu;
201 
202 	struct cpufreq_policy new_pol = {
203 		.min = 0,
204 		.max = 0,
205 		.governor = NULL,
206 	};
207 
208 	/* parameter parsing */
209 	do {
210 		ret = getopt_long(argc, argv, "d:u:g:f:r", set_opts, NULL);
211 		switch (ret) {
212 		case '?':
213 			print_unknown_arg();
214 			return -EINVAL;
215 		case -1:
216 			cont = 0;
217 			break;
218 		case 'r':
219 			if (related)
220 				double_parm++;
221 			related++;
222 			break;
223 		case 'd':
224 			if (new_pol.min)
225 				double_parm++;
226 			policychange++;
227 			new_pol.min = string_to_frequency(optarg);
228 			if (new_pol.min == 0) {
229 				print_unknown_arg();
230 				return -EINVAL;
231 			}
232 			break;
233 		case 'u':
234 			if (new_pol.max)
235 				double_parm++;
236 			policychange++;
237 			new_pol.max = string_to_frequency(optarg);
238 			if (new_pol.max == 0) {
239 				print_unknown_arg();
240 				return -EINVAL;
241 			}
242 			break;
243 		case 'f':
244 			if (freq)
245 				double_parm++;
246 			freq = string_to_frequency(optarg);
247 			if (freq == 0) {
248 				print_unknown_arg();
249 				return -EINVAL;
250 			}
251 			break;
252 		case 'g':
253 			if (new_pol.governor)
254 				double_parm++;
255 			policychange++;
256 			if ((strlen(optarg) < 3) || (strlen(optarg) > 18)) {
257 				print_unknown_arg();
258 				return -EINVAL;
259 			}
260 			if ((sscanf(optarg, "%s", gov)) != 1) {
261 				print_unknown_arg();
262 				return -EINVAL;
263 			}
264 			new_pol.governor = gov;
265 			break;
266 		}
267 	} while (cont);
268 
269 	/* parameter checking */
270 	if (double_parm) {
271 		printf("the same parameter was passed more than once\n");
272 		return -EINVAL;
273 	}
274 
275 	if (freq && policychange) {
276 		printf(_("the -f/--freq parameter cannot be combined with -d/--min, -u/--max or\n"
277 				"-g/--governor parameters\n"));
278 		return -EINVAL;
279 	}
280 
281 	if (!freq && !policychange) {
282 		printf(_("At least one parameter out of -f/--freq, -d/--min, -u/--max, and\n"
283 				"-g/--governor must be passed\n"));
284 		return -EINVAL;
285 	}
286 
287 	/* Default is: set all CPUs */
288 	if (bitmask_isallclear(cpus_chosen))
289 		bitmask_setall(cpus_chosen);
290 
291 	/* Also set frequency settings for related CPUs if -r is passed */
292 	if (related) {
293 		for (cpu = bitmask_first(cpus_chosen);
294 		     cpu <= bitmask_last(cpus_chosen); cpu++) {
295 			struct cpufreq_affected_cpus *cpus;
296 
297 			if (!bitmask_isbitset(cpus_chosen, cpu) ||
298 			    cpufreq_cpu_exists(cpu))
299 				continue;
300 
301 			cpus = cpufreq_get_related_cpus(cpu);
302 			if (!cpus)
303 				break;
304 			while (cpus->next) {
305 				bitmask_setbit(cpus_chosen, cpus->cpu);
306 				cpus = cpus->next;
307 			}
308 			cpufreq_put_related_cpus(cpus);
309 		}
310 	}
311 
312 
313 	/* loop over CPUs */
314 	for (cpu = bitmask_first(cpus_chosen);
315 	     cpu <= bitmask_last(cpus_chosen); cpu++) {
316 
317 		if (!bitmask_isbitset(cpus_chosen, cpu) ||
318 		    cpufreq_cpu_exists(cpu))
319 			continue;
320 
321 		printf(_("Setting cpu: %d\n"), cpu);
322 		ret = do_one_cpu(cpu, &new_pol, freq, policychange);
323 		if (ret)
324 			break;
325 	}
326 
327 	if (ret)
328 		print_error();
329 
330 	return ret;
331 }
332