1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2002,2003 Intrinsyc Software
4 *
5 * History:
6 * 31-Jul-2002 : Initial version [FB]
7 * 29-Jan-2003 : added PXA255 support [FB]
8 * 20-Apr-2003 : ported to v2.5 (Dustin McIntire, Sensoria Corp.)
9 *
10 * Note:
11 * This driver may change the memory bus clock rate, but will not do any
12 * platform specific access timing changes... for example if you have flash
13 * memory connected to CS0, you will need to register a platform specific
14 * notifier which will adjust the memory access strobes to maintain a
15 * minimum strobe width.
16 */
17
18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/sched.h>
23 #include <linux/init.h>
24 #include <linux/cpufreq.h>
25 #include <linux/err.h>
26 #include <linux/regulator/consumer.h>
27 #include <linux/io.h>
28
29 #include <mach/pxa2xx-regs.h>
30 #include <mach/smemc.h>
31
32 #ifdef DEBUG
33 static unsigned int freq_debug;
34 module_param(freq_debug, uint, 0);
35 MODULE_PARM_DESC(freq_debug, "Set the debug messages to on=1/off=0");
36 #else
37 #define freq_debug 0
38 #endif
39
40 static struct regulator *vcc_core;
41
42 static unsigned int pxa27x_maxfreq;
43 module_param(pxa27x_maxfreq, uint, 0);
44 MODULE_PARM_DESC(pxa27x_maxfreq, "Set the pxa27x maxfreq in MHz"
45 "(typically 624=>pxa270, 416=>pxa271, 520=>pxa272)");
46
47 struct pxa_cpufreq_data {
48 struct clk *clk_core;
49 };
50 static struct pxa_cpufreq_data pxa_cpufreq_data;
51
52 struct pxa_freqs {
53 unsigned int khz;
54 int vmin;
55 int vmax;
56 };
57
58 /*
59 * PXA255 definitions
60 */
61 static const struct pxa_freqs pxa255_run_freqs[] =
62 {
63 /* CPU MEMBUS run turbo PXbus SDRAM */
64 { 99500, -1, -1}, /* 99, 99, 50, 50 */
65 {132700, -1, -1}, /* 133, 133, 66, 66 */
66 {199100, -1, -1}, /* 199, 199, 99, 99 */
67 {265400, -1, -1}, /* 265, 265, 133, 66 */
68 {331800, -1, -1}, /* 331, 331, 166, 83 */
69 {398100, -1, -1}, /* 398, 398, 196, 99 */
70 };
71
72 /* Use the turbo mode frequencies for the CPUFREQ_POLICY_POWERSAVE policy */
73 static const struct pxa_freqs pxa255_turbo_freqs[] =
74 {
75 /* CPU run turbo PXbus SDRAM */
76 { 99500, -1, -1}, /* 99, 99, 50, 50 */
77 {199100, -1, -1}, /* 99, 199, 50, 99 */
78 {298500, -1, -1}, /* 99, 287, 50, 99 */
79 {298600, -1, -1}, /* 199, 287, 99, 99 */
80 {398100, -1, -1}, /* 199, 398, 99, 99 */
81 };
82
83 #define NUM_PXA25x_RUN_FREQS ARRAY_SIZE(pxa255_run_freqs)
84 #define NUM_PXA25x_TURBO_FREQS ARRAY_SIZE(pxa255_turbo_freqs)
85
86 static struct cpufreq_frequency_table
87 pxa255_run_freq_table[NUM_PXA25x_RUN_FREQS+1];
88 static struct cpufreq_frequency_table
89 pxa255_turbo_freq_table[NUM_PXA25x_TURBO_FREQS+1];
90
91 static unsigned int pxa255_turbo_table;
92 module_param(pxa255_turbo_table, uint, 0);
93 MODULE_PARM_DESC(pxa255_turbo_table, "Selects the frequency table (0 = run table, !0 = turbo table)");
94
95 static struct pxa_freqs pxa27x_freqs[] = {
96 {104000, 900000, 1705000 },
97 {156000, 1000000, 1705000 },
98 {208000, 1180000, 1705000 },
99 {312000, 1250000, 1705000 },
100 {416000, 1350000, 1705000 },
101 {520000, 1450000, 1705000 },
102 {624000, 1550000, 1705000 }
103 };
104
105 #define NUM_PXA27x_FREQS ARRAY_SIZE(pxa27x_freqs)
106 static struct cpufreq_frequency_table
107 pxa27x_freq_table[NUM_PXA27x_FREQS+1];
108
109 extern unsigned get_clk_frequency_khz(int info);
110
111 #ifdef CONFIG_REGULATOR
112
pxa_cpufreq_change_voltage(const struct pxa_freqs * pxa_freq)113 static int pxa_cpufreq_change_voltage(const struct pxa_freqs *pxa_freq)
114 {
115 int ret = 0;
116 int vmin, vmax;
117
118 if (!cpu_is_pxa27x())
119 return 0;
120
121 vmin = pxa_freq->vmin;
122 vmax = pxa_freq->vmax;
123 if ((vmin == -1) || (vmax == -1))
124 return 0;
125
126 ret = regulator_set_voltage(vcc_core, vmin, vmax);
127 if (ret)
128 pr_err("Failed to set vcc_core in [%dmV..%dmV]\n", vmin, vmax);
129 return ret;
130 }
131
pxa_cpufreq_init_voltages(void)132 static void pxa_cpufreq_init_voltages(void)
133 {
134 vcc_core = regulator_get(NULL, "vcc_core");
135 if (IS_ERR(vcc_core)) {
136 pr_info("Didn't find vcc_core regulator\n");
137 vcc_core = NULL;
138 } else {
139 pr_info("Found vcc_core regulator\n");
140 }
141 }
142 #else
pxa_cpufreq_change_voltage(const struct pxa_freqs * pxa_freq)143 static int pxa_cpufreq_change_voltage(const struct pxa_freqs *pxa_freq)
144 {
145 return 0;
146 }
147
pxa_cpufreq_init_voltages(void)148 static void pxa_cpufreq_init_voltages(void) { }
149 #endif
150
find_freq_tables(struct cpufreq_frequency_table ** freq_table,const struct pxa_freqs ** pxa_freqs)151 static void find_freq_tables(struct cpufreq_frequency_table **freq_table,
152 const struct pxa_freqs **pxa_freqs)
153 {
154 if (cpu_is_pxa25x()) {
155 if (!pxa255_turbo_table) {
156 *pxa_freqs = pxa255_run_freqs;
157 *freq_table = pxa255_run_freq_table;
158 } else {
159 *pxa_freqs = pxa255_turbo_freqs;
160 *freq_table = pxa255_turbo_freq_table;
161 }
162 } else if (cpu_is_pxa27x()) {
163 *pxa_freqs = pxa27x_freqs;
164 *freq_table = pxa27x_freq_table;
165 } else {
166 BUG();
167 }
168 }
169
pxa27x_guess_max_freq(void)170 static void pxa27x_guess_max_freq(void)
171 {
172 if (!pxa27x_maxfreq) {
173 pxa27x_maxfreq = 416000;
174 pr_info("PXA CPU 27x max frequency not defined (pxa27x_maxfreq), assuming pxa271 with %dkHz maxfreq\n",
175 pxa27x_maxfreq);
176 } else {
177 pxa27x_maxfreq *= 1000;
178 }
179 }
180
pxa_cpufreq_get(unsigned int cpu)181 static unsigned int pxa_cpufreq_get(unsigned int cpu)
182 {
183 struct pxa_cpufreq_data *data = cpufreq_get_driver_data();
184
185 return (unsigned int) clk_get_rate(data->clk_core) / 1000;
186 }
187
pxa_set_target(struct cpufreq_policy * policy,unsigned int idx)188 static int pxa_set_target(struct cpufreq_policy *policy, unsigned int idx)
189 {
190 struct cpufreq_frequency_table *pxa_freqs_table;
191 const struct pxa_freqs *pxa_freq_settings;
192 struct pxa_cpufreq_data *data = cpufreq_get_driver_data();
193 unsigned int new_freq_cpu;
194 int ret = 0;
195
196 /* Get the current policy */
197 find_freq_tables(&pxa_freqs_table, &pxa_freq_settings);
198
199 new_freq_cpu = pxa_freq_settings[idx].khz;
200
201 if (freq_debug)
202 pr_debug("Changing CPU frequency from %d Mhz to %d Mhz\n",
203 policy->cur / 1000, new_freq_cpu / 1000);
204
205 if (vcc_core && new_freq_cpu > policy->cur) {
206 ret = pxa_cpufreq_change_voltage(&pxa_freq_settings[idx]);
207 if (ret)
208 return ret;
209 }
210
211 clk_set_rate(data->clk_core, new_freq_cpu * 1000);
212
213 /*
214 * Even if voltage setting fails, we don't report it, as the frequency
215 * change succeeded. The voltage reduction is not a critical failure,
216 * only power savings will suffer from this.
217 *
218 * Note: if the voltage change fails, and a return value is returned, a
219 * bug is triggered (seems a deadlock). Should anybody find out where,
220 * the "return 0" should become a "return ret".
221 */
222 if (vcc_core && new_freq_cpu < policy->cur)
223 ret = pxa_cpufreq_change_voltage(&pxa_freq_settings[idx]);
224
225 return 0;
226 }
227
pxa_cpufreq_init(struct cpufreq_policy * policy)228 static int pxa_cpufreq_init(struct cpufreq_policy *policy)
229 {
230 int i;
231 unsigned int freq;
232 struct cpufreq_frequency_table *pxa255_freq_table;
233 const struct pxa_freqs *pxa255_freqs;
234
235 /* try to guess pxa27x cpu */
236 if (cpu_is_pxa27x())
237 pxa27x_guess_max_freq();
238
239 pxa_cpufreq_init_voltages();
240
241 /* set default policy and cpuinfo */
242 policy->cpuinfo.transition_latency = 1000; /* FIXME: 1 ms, assumed */
243
244 /* Generate pxa25x the run cpufreq_frequency_table struct */
245 for (i = 0; i < NUM_PXA25x_RUN_FREQS; i++) {
246 pxa255_run_freq_table[i].frequency = pxa255_run_freqs[i].khz;
247 pxa255_run_freq_table[i].driver_data = i;
248 }
249 pxa255_run_freq_table[i].frequency = CPUFREQ_TABLE_END;
250
251 /* Generate pxa25x the turbo cpufreq_frequency_table struct */
252 for (i = 0; i < NUM_PXA25x_TURBO_FREQS; i++) {
253 pxa255_turbo_freq_table[i].frequency =
254 pxa255_turbo_freqs[i].khz;
255 pxa255_turbo_freq_table[i].driver_data = i;
256 }
257 pxa255_turbo_freq_table[i].frequency = CPUFREQ_TABLE_END;
258
259 pxa255_turbo_table = !!pxa255_turbo_table;
260
261 /* Generate the pxa27x cpufreq_frequency_table struct */
262 for (i = 0; i < NUM_PXA27x_FREQS; i++) {
263 freq = pxa27x_freqs[i].khz;
264 if (freq > pxa27x_maxfreq)
265 break;
266 pxa27x_freq_table[i].frequency = freq;
267 pxa27x_freq_table[i].driver_data = i;
268 }
269 pxa27x_freq_table[i].driver_data = i;
270 pxa27x_freq_table[i].frequency = CPUFREQ_TABLE_END;
271
272 /*
273 * Set the policy's minimum and maximum frequencies from the tables
274 * just constructed. This sets cpuinfo.mxx_freq, min and max.
275 */
276 if (cpu_is_pxa25x()) {
277 find_freq_tables(&pxa255_freq_table, &pxa255_freqs);
278 pr_info("using %s frequency table\n",
279 pxa255_turbo_table ? "turbo" : "run");
280
281 policy->freq_table = pxa255_freq_table;
282 }
283 else if (cpu_is_pxa27x()) {
284 policy->freq_table = pxa27x_freq_table;
285 }
286
287 pr_info("frequency change support initialized\n");
288
289 return 0;
290 }
291
292 static struct cpufreq_driver pxa_cpufreq_driver = {
293 .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
294 .verify = cpufreq_generic_frequency_table_verify,
295 .target_index = pxa_set_target,
296 .init = pxa_cpufreq_init,
297 .get = pxa_cpufreq_get,
298 .name = "PXA2xx",
299 .driver_data = &pxa_cpufreq_data,
300 };
301
pxa_cpu_init(void)302 static int __init pxa_cpu_init(void)
303 {
304 int ret = -ENODEV;
305
306 pxa_cpufreq_data.clk_core = clk_get_sys(NULL, "core");
307 if (IS_ERR(pxa_cpufreq_data.clk_core))
308 return PTR_ERR(pxa_cpufreq_data.clk_core);
309
310 if (cpu_is_pxa25x() || cpu_is_pxa27x())
311 ret = cpufreq_register_driver(&pxa_cpufreq_driver);
312 return ret;
313 }
314
pxa_cpu_exit(void)315 static void __exit pxa_cpu_exit(void)
316 {
317 cpufreq_unregister_driver(&pxa_cpufreq_driver);
318 }
319
320
321 MODULE_AUTHOR("Intrinsyc Software Inc.");
322 MODULE_DESCRIPTION("CPU frequency changing driver for the PXA architecture");
323 MODULE_LICENSE("GPL");
324 module_init(pxa_cpu_init);
325 module_exit(pxa_cpu_exit);
326
