Merge branch 'for-linus' of git://git.kernel.dk/linux-block
[linux-2.6-block.git] / drivers / cpufreq / pxa2xx-cpufreq.c
CommitLineData
9e2697ff 1/*
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2 * Copyright (C) 2002,2003 Intrinsyc Software
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * History:
19 * 31-Jul-2002 : Initial version [FB]
20 * 29-Jan-2003 : added PXA255 support [FB]
21 * 20-Apr-2003 : ported to v2.5 (Dustin McIntire, Sensoria Corp.)
22 *
23 * Note:
24 * This driver may change the memory bus clock rate, but will not do any
25 * platform specific access timing changes... for example if you have flash
26 * memory connected to CS0, you will need to register a platform specific
27 * notifier which will adjust the memory access strobes to maintain a
28 * minimum strobe width.
29 *
30 */
31
32#include <linux/kernel.h>
33#include <linux/module.h>
34#include <linux/sched.h>
35#include <linux/init.h>
36#include <linux/cpufreq.h>
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37#include <linux/err.h>
38#include <linux/regulator/consumer.h>
ad68bb9f 39#include <linux/io.h>
9e2697ff 40
a09e64fb 41#include <mach/pxa2xx-regs.h>
ad68bb9f 42#include <mach/smemc.h>
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43
44#ifdef DEBUG
45static unsigned int freq_debug;
c710e39c 46module_param(freq_debug, uint, 0);
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47MODULE_PARM_DESC(freq_debug, "Set the debug messages to on=1/off=0");
48#else
49#define freq_debug 0
50#endif
51
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52static struct regulator *vcc_core;
53
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54static unsigned int pxa27x_maxfreq;
55module_param(pxa27x_maxfreq, uint, 0);
56MODULE_PARM_DESC(pxa27x_maxfreq, "Set the pxa27x maxfreq in MHz"
57 "(typically 624=>pxa270, 416=>pxa271, 520=>pxa272)");
58
52352558 59struct pxa_freqs {
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60 unsigned int khz;
61 unsigned int membus;
62 unsigned int cccr;
63 unsigned int div2;
592eb999 64 unsigned int cclkcfg;
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65 int vmin;
66 int vmax;
52352558 67};
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68
69/* Define the refresh period in mSec for the SDRAM and the number of rows */
3679389b 70#define SDRAM_TREF 64 /* standard 64ms SDRAM */
a10c287d 71static unsigned int sdram_rows;
9e2697ff 72
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73#define CCLKCFG_TURBO 0x1
74#define CCLKCFG_FCS 0x2
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75#define CCLKCFG_HALFTURBO 0x4
76#define CCLKCFG_FASTBUS 0x8
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77#define MDREFR_DB2_MASK (MDREFR_K2DB2 | MDREFR_K1DB2)
78#define MDREFR_DRI_MASK 0xFFF
9e2697ff 79
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80#define MDCNFG_DRAC2(mdcnfg) (((mdcnfg) >> 21) & 0x3)
81#define MDCNFG_DRAC0(mdcnfg) (((mdcnfg) >> 5) & 0x3)
82
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83/*
84 * PXA255 definitions
85 */
9e2697ff 86/* Use the run mode frequencies for the CPUFREQ_POLICY_PERFORMANCE policy */
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87#define CCLKCFG CCLKCFG_TURBO | CCLKCFG_FCS
88
03c22990 89static const struct pxa_freqs pxa255_run_freqs[] =
9e2697ff 90{
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91 /* CPU MEMBUS CCCR DIV2 CCLKCFG run turbo PXbus SDRAM */
92 { 99500, 99500, 0x121, 1, CCLKCFG, -1, -1}, /* 99, 99, 50, 50 */
93 {132700, 132700, 0x123, 1, CCLKCFG, -1, -1}, /* 133, 133, 66, 66 */
94 {199100, 99500, 0x141, 0, CCLKCFG, -1, -1}, /* 199, 199, 99, 99 */
95 {265400, 132700, 0x143, 1, CCLKCFG, -1, -1}, /* 265, 265, 133, 66 */
96 {331800, 165900, 0x145, 1, CCLKCFG, -1, -1}, /* 331, 331, 166, 83 */
97 {398100, 99500, 0x161, 0, CCLKCFG, -1, -1}, /* 398, 398, 196, 99 */
9e2697ff 98};
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99
100/* Use the turbo mode frequencies for the CPUFREQ_POLICY_POWERSAVE policy */
03c22990 101static const struct pxa_freqs pxa255_turbo_freqs[] =
9e2697ff 102{
592eb999 103 /* CPU MEMBUS CCCR DIV2 CCLKCFG run turbo PXbus SDRAM */
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104 { 99500, 99500, 0x121, 1, CCLKCFG, -1, -1}, /* 99, 99, 50, 50 */
105 {199100, 99500, 0x221, 0, CCLKCFG, -1, -1}, /* 99, 199, 50, 99 */
106 {298500, 99500, 0x321, 0, CCLKCFG, -1, -1}, /* 99, 287, 50, 99 */
107 {298600, 99500, 0x1c1, 0, CCLKCFG, -1, -1}, /* 199, 287, 99, 99 */
108 {398100, 99500, 0x241, 0, CCLKCFG, -1, -1}, /* 199, 398, 99, 99 */
9e2697ff 109};
9e2697ff 110
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111#define NUM_PXA25x_RUN_FREQS ARRAY_SIZE(pxa255_run_freqs)
112#define NUM_PXA25x_TURBO_FREQS ARRAY_SIZE(pxa255_turbo_freqs)
113
114static struct cpufreq_frequency_table
115 pxa255_run_freq_table[NUM_PXA25x_RUN_FREQS+1];
3679389b 116static struct cpufreq_frequency_table
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117 pxa255_turbo_freq_table[NUM_PXA25x_TURBO_FREQS+1];
118
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119static unsigned int pxa255_turbo_table;
120module_param(pxa255_turbo_table, uint, 0);
121MODULE_PARM_DESC(pxa255_turbo_table, "Selects the frequency table (0 = run table, !0 = turbo table)");
122
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123/*
124 * PXA270 definitions
125 *
126 * For the PXA27x:
127 * Control variables are A, L, 2N for CCCR; B, HT, T for CLKCFG.
128 *
129 * A = 0 => memory controller clock from table 3-7,
130 * A = 1 => memory controller clock = system bus clock
131 * Run mode frequency = 13 MHz * L
132 * Turbo mode frequency = 13 MHz * L * N
133 * System bus frequency = 13 MHz * L / (B + 1)
134 *
135 * In CCCR:
136 * A = 1
137 * L = 16 oscillator to run mode ratio
138 * 2N = 6 2 * (turbo mode to run mode ratio)
139 *
140 * In CCLKCFG:
141 * B = 1 Fast bus mode
142 * HT = 0 Half-Turbo mode
143 * T = 1 Turbo mode
144 *
145 * For now, just support some of the combinations in table 3-7 of
146 * PXA27x Processor Family Developer's Manual to simplify frequency
147 * change sequences.
148 */
149#define PXA27x_CCCR(A, L, N2) (A << 25 | N2 << 7 | L)
150#define CCLKCFG2(B, HT, T) \
151 (CCLKCFG_FCS | \
152 ((B) ? CCLKCFG_FASTBUS : 0) | \
153 ((HT) ? CCLKCFG_HALFTURBO : 0) | \
154 ((T) ? CCLKCFG_TURBO : 0))
155
52352558 156static struct pxa_freqs pxa27x_freqs[] = {
3dbeef23 157 {104000, 104000, PXA27x_CCCR(1, 8, 2), 0, CCLKCFG2(1, 0, 1), 900000, 1705000 },
4367216a 158 {156000, 104000, PXA27x_CCCR(1, 8, 3), 0, CCLKCFG2(1, 0, 1), 1000000, 1705000 },
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159 {208000, 208000, PXA27x_CCCR(0, 16, 2), 1, CCLKCFG2(0, 0, 1), 1180000, 1705000 },
160 {312000, 208000, PXA27x_CCCR(1, 16, 3), 1, CCLKCFG2(1, 0, 1), 1250000, 1705000 },
161 {416000, 208000, PXA27x_CCCR(1, 16, 4), 1, CCLKCFG2(1, 0, 1), 1350000, 1705000 },
162 {520000, 208000, PXA27x_CCCR(1, 16, 5), 1, CCLKCFG2(1, 0, 1), 1450000, 1705000 },
163 {624000, 208000, PXA27x_CCCR(1, 16, 6), 1, CCLKCFG2(1, 0, 1), 1550000, 1705000 }
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164};
165
166#define NUM_PXA27x_FREQS ARRAY_SIZE(pxa27x_freqs)
167static struct cpufreq_frequency_table
168 pxa27x_freq_table[NUM_PXA27x_FREQS+1];
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169
170extern unsigned get_clk_frequency_khz(int info);
171
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172#ifdef CONFIG_REGULATOR
173
03c22990 174static int pxa_cpufreq_change_voltage(const struct pxa_freqs *pxa_freq)
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175{
176 int ret = 0;
177 int vmin, vmax;
178
179 if (!cpu_is_pxa27x())
180 return 0;
181
182 vmin = pxa_freq->vmin;
183 vmax = pxa_freq->vmax;
184 if ((vmin == -1) || (vmax == -1))
185 return 0;
186
187 ret = regulator_set_voltage(vcc_core, vmin, vmax);
188 if (ret)
189 pr_err("cpufreq: Failed to set vcc_core in [%dmV..%dmV]\n",
190 vmin, vmax);
191 return ret;
192}
193
295dbde1 194static void __init pxa_cpufreq_init_voltages(void)
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195{
196 vcc_core = regulator_get(NULL, "vcc_core");
197 if (IS_ERR(vcc_core)) {
198 pr_info("cpufreq: Didn't find vcc_core regulator\n");
199 vcc_core = NULL;
200 } else {
201 pr_info("cpufreq: Found vcc_core regulator\n");
202 }
203}
204#else
52352558 205static int pxa_cpufreq_change_voltage(struct pxa_freqs *pxa_freq)
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206{
207 return 0;
208}
209
295dbde1 210static void __init pxa_cpufreq_init_voltages(void) { }
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211#endif
212
65587f7d 213static void find_freq_tables(struct cpufreq_frequency_table **freq_table,
03c22990 214 const struct pxa_freqs **pxa_freqs)
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215{
216 if (cpu_is_pxa25x()) {
65587f7d 217 if (!pxa255_turbo_table) {
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218 *pxa_freqs = pxa255_run_freqs;
219 *freq_table = pxa255_run_freq_table;
65587f7d 220 } else {
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221 *pxa_freqs = pxa255_turbo_freqs;
222 *freq_table = pxa255_turbo_freq_table;
592eb999 223 }
7264a2bb 224 } else if (cpu_is_pxa27x()) {
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225 *pxa_freqs = pxa27x_freqs;
226 *freq_table = pxa27x_freq_table;
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227 } else {
228 BUG();
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229 }
230}
231
232static void pxa27x_guess_max_freq(void)
233{
234 if (!pxa27x_maxfreq) {
235 pxa27x_maxfreq = 416000;
236 printk(KERN_INFO "PXA CPU 27x max frequency not defined "
237 "(pxa27x_maxfreq), assuming pxa271 with %dkHz maxfreq\n",
238 pxa27x_maxfreq);
239 } else {
240 pxa27x_maxfreq *= 1000;
241 }
242}
243
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244static void init_sdram_rows(void)
245{
ad68bb9f 246 uint32_t mdcnfg = __raw_readl(MDCNFG);
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247 unsigned int drac2 = 0, drac0 = 0;
248
249 if (mdcnfg & (MDCNFG_DE2 | MDCNFG_DE3))
250 drac2 = MDCNFG_DRAC2(mdcnfg);
251
252 if (mdcnfg & (MDCNFG_DE0 | MDCNFG_DE1))
253 drac0 = MDCNFG_DRAC0(mdcnfg);
254
255 sdram_rows = 1 << (11 + max(drac0, drac2));
256}
257
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258static u32 mdrefr_dri(unsigned int freq)
259{
3d3d0fbf 260 u32 interval = freq * SDRAM_TREF / sdram_rows;
592eb999 261
3d3d0fbf 262 return (interval - (cpu_is_pxa27x() ? 31 : 0)) / 32;
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263}
264
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265static unsigned int pxa_cpufreq_get(unsigned int cpu)
266{
267 return get_clk_frequency_khz(0);
268}
269
9c0ebcf7 270static int pxa_set_target(struct cpufreq_policy *policy, unsigned int idx)
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271{
272 struct cpufreq_frequency_table *pxa_freqs_table;
03c22990 273 const struct pxa_freqs *pxa_freq_settings;
9e2697ff 274 unsigned long flags;
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275 unsigned int new_freq_cpu, new_freq_mem;
276 unsigned int unused, preset_mdrefr, postset_mdrefr, cclkcfg;
3dbeef23 277 int ret = 0;
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278
279 /* Get the current policy */
65587f7d 280 find_freq_tables(&pxa_freqs_table, &pxa_freq_settings);
9e2697ff 281
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282 new_freq_cpu = pxa_freq_settings[idx].khz;
283 new_freq_mem = pxa_freq_settings[idx].membus;
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284
285 if (freq_debug)
d4202806 286 pr_debug("Changing CPU frequency to %d Mhz, (SDRAM %d Mhz)\n",
d4019f0a 287 new_freq_cpu / 1000, (pxa_freq_settings[idx].div2) ?
592eb999 288 (new_freq_mem / 2000) : (new_freq_mem / 1000));
9e2697ff 289
d4019f0a 290 if (vcc_core && new_freq_cpu > policy->cur) {
3dbeef23 291 ret = pxa_cpufreq_change_voltage(&pxa_freq_settings[idx]);
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292 if (ret)
293 return ret;
294 }
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295
296 /* Calculate the next MDREFR. If we're slowing down the SDRAM clock
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297 * we need to preset the smaller DRI before the change. If we're
298 * speeding up we need to set the larger DRI value after the change.
9e2697ff 299 */
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300 preset_mdrefr = postset_mdrefr = __raw_readl(MDREFR);
301 if ((preset_mdrefr & MDREFR_DRI_MASK) > mdrefr_dri(new_freq_mem)) {
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302 preset_mdrefr = (preset_mdrefr & ~MDREFR_DRI_MASK);
303 preset_mdrefr |= mdrefr_dri(new_freq_mem);
9e2697ff 304 }
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305 postset_mdrefr =
306 (postset_mdrefr & ~MDREFR_DRI_MASK) | mdrefr_dri(new_freq_mem);
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307
308 /* If we're dividing the memory clock by two for the SDRAM clock, this
309 * must be set prior to the change. Clearing the divide must be done
310 * after the change.
311 */
312 if (pxa_freq_settings[idx].div2) {
313 preset_mdrefr |= MDREFR_DB2_MASK;
314 postset_mdrefr |= MDREFR_DB2_MASK;
315 } else {
316 postset_mdrefr &= ~MDREFR_DB2_MASK;
317 }
318
319 local_irq_save(flags);
320
592eb999 321 /* Set new the CCCR and prepare CCLKCFG */
9e2697ff 322 CCCR = pxa_freq_settings[idx].cccr;
592eb999 323 cclkcfg = pxa_freq_settings[idx].cclkcfg;
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324
325 asm volatile(" \n\
326 ldr r4, [%1] /* load MDREFR */ \n\
327 b 2f \n\
3679389b 328 .align 5 \n\
9e2697ff 3291: \n\
592eb999 330 str %3, [%1] /* preset the MDREFR */ \n\
9e2697ff 331 mcr p14, 0, %2, c6, c0, 0 /* set CCLKCFG[FCS] */ \n\
592eb999 332 str %4, [%1] /* postset the MDREFR */ \n\
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333 \n\
334 b 3f \n\
3352: b 1b \n\
3363: nop \n\
337 "
3679389b 338 : "=&r" (unused)
ad68bb9f 339 : "r" (MDREFR), "r" (cclkcfg),
592eb999 340 "r" (preset_mdrefr), "r" (postset_mdrefr)
3679389b 341 : "r4", "r5");
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342 local_irq_restore(flags);
343
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344 /*
345 * Even if voltage setting fails, we don't report it, as the frequency
346 * change succeeded. The voltage reduction is not a critical failure,
347 * only power savings will suffer from this.
348 *
349 * Note: if the voltage change fails, and a return value is returned, a
350 * bug is triggered (seems a deadlock). Should anybody find out where,
351 * the "return 0" should become a "return ret".
352 */
d4019f0a 353 if (vcc_core && new_freq_cpu < policy->cur)
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354 ret = pxa_cpufreq_change_voltage(&pxa_freq_settings[idx]);
355
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356 return 0;
357}
358
50e77fcd 359static int pxa_cpufreq_init(struct cpufreq_policy *policy)
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360{
361 int i;
592eb999 362 unsigned int freq;
65587f7d 363 struct cpufreq_frequency_table *pxa255_freq_table;
03c22990 364 const struct pxa_freqs *pxa255_freqs;
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365
366 /* try to guess pxa27x cpu */
367 if (cpu_is_pxa27x())
368 pxa27x_guess_max_freq();
9e2697ff 369
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370 pxa_cpufreq_init_voltages();
371
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372 init_sdram_rows();
373
9e2697ff 374 /* set default policy and cpuinfo */
9e2697ff 375 policy->cpuinfo.transition_latency = 1000; /* FIXME: 1 ms, assumed */
9e2697ff 376
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377 /* Generate pxa25x the run cpufreq_frequency_table struct */
378 for (i = 0; i < NUM_PXA25x_RUN_FREQS; i++) {
9e2697ff 379 pxa255_run_freq_table[i].frequency = pxa255_run_freqs[i].khz;
50701588 380 pxa255_run_freq_table[i].driver_data = i;
9e2697ff 381 }
9e2697ff 382 pxa255_run_freq_table[i].frequency = CPUFREQ_TABLE_END;
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383
384 /* Generate pxa25x the turbo cpufreq_frequency_table struct */
385 for (i = 0; i < NUM_PXA25x_TURBO_FREQS; i++) {
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386 pxa255_turbo_freq_table[i].frequency =
387 pxa255_turbo_freqs[i].khz;
50701588 388 pxa255_turbo_freq_table[i].driver_data = i;
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389 }
390 pxa255_turbo_freq_table[i].frequency = CPUFREQ_TABLE_END;
391
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392 pxa255_turbo_table = !!pxa255_turbo_table;
393
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394 /* Generate the pxa27x cpufreq_frequency_table struct */
395 for (i = 0; i < NUM_PXA27x_FREQS; i++) {
396 freq = pxa27x_freqs[i].khz;
397 if (freq > pxa27x_maxfreq)
398 break;
399 pxa27x_freq_table[i].frequency = freq;
50701588 400 pxa27x_freq_table[i].driver_data = i;
592eb999 401 }
50701588 402 pxa27x_freq_table[i].driver_data = i;
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403 pxa27x_freq_table[i].frequency = CPUFREQ_TABLE_END;
404
405 /*
406 * Set the policy's minimum and maximum frequencies from the tables
407 * just constructed. This sets cpuinfo.mxx_freq, min and max.
408 */
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409 if (cpu_is_pxa25x()) {
410 find_freq_tables(&pxa255_freq_table, &pxa255_freqs);
411 pr_info("PXA255 cpufreq using %s frequency table\n",
412 pxa255_turbo_table ? "turbo" : "run");
6a77a1e6 413
15cc921b 414 cpufreq_table_validate_and_show(policy, pxa255_freq_table);
65587f7d 415 }
6a77a1e6 416 else if (cpu_is_pxa27x()) {
15cc921b 417 cpufreq_table_validate_and_show(policy, pxa27x_freq_table);
6a77a1e6 418 }
592eb999 419
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420 printk(KERN_INFO "PXA CPU frequency change support initialized\n");
421
422 return 0;
423}
424
425static struct cpufreq_driver pxa_cpufreq_driver = {
ae6b4271 426 .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
bf36e48d 427 .verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7 428 .target_index = pxa_set_target,
9e2697ff 429 .init = pxa_cpufreq_init,
ea833f0b 430 .get = pxa_cpufreq_get,
592eb999 431 .name = "PXA2xx",
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432};
433
434static int __init pxa_cpu_init(void)
435{
436 int ret = -ENODEV;
592eb999 437 if (cpu_is_pxa25x() || cpu_is_pxa27x())
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438 ret = cpufreq_register_driver(&pxa_cpufreq_driver);
439 return ret;
440}
441
442static void __exit pxa_cpu_exit(void)
443{
592eb999 444 cpufreq_unregister_driver(&pxa_cpufreq_driver);
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445}
446
447
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448MODULE_AUTHOR("Intrinsyc Software Inc.");
449MODULE_DESCRIPTION("CPU frequency changing driver for the PXA architecture");
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450MODULE_LICENSE("GPL");
451module_init(pxa_cpu_init);
452module_exit(pxa_cpu_exit);