pmac64-cpufreq.c 19 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706
  1. /*
  2. * Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
  3. * and Markus Demleitner <msdemlei@cl.uni-heidelberg.de>
  4. *
  5. * This program is free software; you can redistribute it and/or modify
  6. * it under the terms of the GNU General Public License version 2 as
  7. * published by the Free Software Foundation.
  8. *
  9. * This driver adds basic cpufreq support for SMU & 970FX based G5 Macs,
  10. * that is iMac G5 and latest single CPU desktop.
  11. */
  12. #undef DEBUG
  13. #include <linux/module.h>
  14. #include <linux/types.h>
  15. #include <linux/errno.h>
  16. #include <linux/kernel.h>
  17. #include <linux/delay.h>
  18. #include <linux/sched.h>
  19. #include <linux/cpufreq.h>
  20. #include <linux/init.h>
  21. #include <linux/completion.h>
  22. #include <linux/mutex.h>
  23. #include <linux/of_device.h>
  24. #include <asm/prom.h>
  25. #include <asm/machdep.h>
  26. #include <asm/irq.h>
  27. #include <asm/sections.h>
  28. #include <asm/cputable.h>
  29. #include <asm/time.h>
  30. #include <asm/smu.h>
  31. #include <asm/pmac_pfunc.h>
  32. #define DBG(fmt...) pr_debug(fmt)
  33. /* see 970FX user manual */
  34. #define SCOM_PCR 0x0aa001 /* PCR scom addr */
  35. #define PCR_HILO_SELECT 0x80000000U /* 1 = PCR, 0 = PCRH */
  36. #define PCR_SPEED_FULL 0x00000000U /* 1:1 speed value */
  37. #define PCR_SPEED_HALF 0x00020000U /* 1:2 speed value */
  38. #define PCR_SPEED_QUARTER 0x00040000U /* 1:4 speed value */
  39. #define PCR_SPEED_MASK 0x000e0000U /* speed mask */
  40. #define PCR_SPEED_SHIFT 17
  41. #define PCR_FREQ_REQ_VALID 0x00010000U /* freq request valid */
  42. #define PCR_VOLT_REQ_VALID 0x00008000U /* volt request valid */
  43. #define PCR_TARGET_TIME_MASK 0x00006000U /* target time */
  44. #define PCR_STATLAT_MASK 0x00001f00U /* STATLAT value */
  45. #define PCR_SNOOPLAT_MASK 0x000000f0U /* SNOOPLAT value */
  46. #define PCR_SNOOPACC_MASK 0x0000000fU /* SNOOPACC value */
  47. #define SCOM_PSR 0x408001 /* PSR scom addr */
  48. /* warning: PSR is a 64 bits register */
  49. #define PSR_CMD_RECEIVED 0x2000000000000000U /* command received */
  50. #define PSR_CMD_COMPLETED 0x1000000000000000U /* command completed */
  51. #define PSR_CUR_SPEED_MASK 0x0300000000000000U /* current speed */
  52. #define PSR_CUR_SPEED_SHIFT (56)
  53. /*
  54. * The G5 only supports two frequencies (Quarter speed is not supported)
  55. */
  56. #define CPUFREQ_HIGH 0
  57. #define CPUFREQ_LOW 1
  58. static struct cpufreq_frequency_table g5_cpu_freqs[] = {
  59. {CPUFREQ_HIGH, 0},
  60. {CPUFREQ_LOW, 0},
  61. {0, CPUFREQ_TABLE_END},
  62. };
  63. /* Power mode data is an array of the 32 bits PCR values to use for
  64. * the various frequencies, retrieved from the device-tree
  65. */
  66. static int g5_pmode_cur;
  67. static void (*g5_switch_volt)(int speed_mode);
  68. static int (*g5_switch_freq)(int speed_mode);
  69. static int (*g5_query_freq)(void);
  70. static DEFINE_MUTEX(g5_switch_mutex);
  71. static unsigned long transition_latency;
  72. #ifdef CONFIG_PMAC_SMU
  73. static const u32 *g5_pmode_data;
  74. static int g5_pmode_max;
  75. static struct smu_sdbp_fvt *g5_fvt_table; /* table of op. points */
  76. static int g5_fvt_count; /* number of op. points */
  77. static int g5_fvt_cur; /* current op. point */
  78. /*
  79. * SMU based voltage switching for Neo2 platforms
  80. */
  81. static void g5_smu_switch_volt(int speed_mode)
  82. {
  83. struct smu_simple_cmd cmd;
  84. DECLARE_COMPLETION_ONSTACK(comp);
  85. smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, smu_done_complete,
  86. &comp, 'V', 'S', 'L', 'E', 'W',
  87. 0xff, g5_fvt_cur+1, speed_mode);
  88. wait_for_completion(&comp);
  89. }
  90. /*
  91. * Platform function based voltage/vdnap switching for Neo2
  92. */
  93. static struct pmf_function *pfunc_set_vdnap0;
  94. static struct pmf_function *pfunc_vdnap0_complete;
  95. static void g5_vdnap_switch_volt(int speed_mode)
  96. {
  97. struct pmf_args args;
  98. u32 slew, done = 0;
  99. unsigned long timeout;
  100. slew = (speed_mode == CPUFREQ_LOW) ? 1 : 0;
  101. args.count = 1;
  102. args.u[0].p = &slew;
  103. pmf_call_one(pfunc_set_vdnap0, &args);
  104. /* It's an irq GPIO so we should be able to just block here,
  105. * I'll do that later after I've properly tested the IRQ code for
  106. * platform functions
  107. */
  108. timeout = jiffies + HZ/10;
  109. while(!time_after(jiffies, timeout)) {
  110. args.count = 1;
  111. args.u[0].p = &done;
  112. pmf_call_one(pfunc_vdnap0_complete, &args);
  113. if (done)
  114. break;
  115. msleep(1);
  116. }
  117. if (done == 0)
  118. printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
  119. }
  120. /*
  121. * SCOM based frequency switching for 970FX rev3
  122. */
  123. static int g5_scom_switch_freq(int speed_mode)
  124. {
  125. unsigned long flags;
  126. int to;
  127. /* If frequency is going up, first ramp up the voltage */
  128. if (speed_mode < g5_pmode_cur)
  129. g5_switch_volt(speed_mode);
  130. local_irq_save(flags);
  131. /* Clear PCR high */
  132. scom970_write(SCOM_PCR, 0);
  133. /* Clear PCR low */
  134. scom970_write(SCOM_PCR, PCR_HILO_SELECT | 0);
  135. /* Set PCR low */
  136. scom970_write(SCOM_PCR, PCR_HILO_SELECT |
  137. g5_pmode_data[speed_mode]);
  138. /* Wait for completion */
  139. for (to = 0; to < 10; to++) {
  140. unsigned long psr = scom970_read(SCOM_PSR);
  141. if ((psr & PSR_CMD_RECEIVED) == 0 &&
  142. (((psr >> PSR_CUR_SPEED_SHIFT) ^
  143. (g5_pmode_data[speed_mode] >> PCR_SPEED_SHIFT)) & 0x3)
  144. == 0)
  145. break;
  146. if (psr & PSR_CMD_COMPLETED)
  147. break;
  148. udelay(100);
  149. }
  150. local_irq_restore(flags);
  151. /* If frequency is going down, last ramp the voltage */
  152. if (speed_mode > g5_pmode_cur)
  153. g5_switch_volt(speed_mode);
  154. g5_pmode_cur = speed_mode;
  155. ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
  156. return 0;
  157. }
  158. static int g5_scom_query_freq(void)
  159. {
  160. unsigned long psr = scom970_read(SCOM_PSR);
  161. int i;
  162. for (i = 0; i <= g5_pmode_max; i++)
  163. if ((((psr >> PSR_CUR_SPEED_SHIFT) ^
  164. (g5_pmode_data[i] >> PCR_SPEED_SHIFT)) & 0x3) == 0)
  165. break;
  166. return i;
  167. }
  168. /*
  169. * Fake voltage switching for platforms with missing support
  170. */
  171. static void g5_dummy_switch_volt(int speed_mode)
  172. {
  173. }
  174. #endif /* CONFIG_PMAC_SMU */
  175. /*
  176. * Platform function based voltage switching for PowerMac7,2 & 7,3
  177. */
  178. static struct pmf_function *pfunc_cpu0_volt_high;
  179. static struct pmf_function *pfunc_cpu0_volt_low;
  180. static struct pmf_function *pfunc_cpu1_volt_high;
  181. static struct pmf_function *pfunc_cpu1_volt_low;
  182. static void g5_pfunc_switch_volt(int speed_mode)
  183. {
  184. if (speed_mode == CPUFREQ_HIGH) {
  185. if (pfunc_cpu0_volt_high)
  186. pmf_call_one(pfunc_cpu0_volt_high, NULL);
  187. if (pfunc_cpu1_volt_high)
  188. pmf_call_one(pfunc_cpu1_volt_high, NULL);
  189. } else {
  190. if (pfunc_cpu0_volt_low)
  191. pmf_call_one(pfunc_cpu0_volt_low, NULL);
  192. if (pfunc_cpu1_volt_low)
  193. pmf_call_one(pfunc_cpu1_volt_low, NULL);
  194. }
  195. msleep(10); /* should be faster , to fix */
  196. }
  197. /*
  198. * Platform function based frequency switching for PowerMac7,2 & 7,3
  199. */
  200. static struct pmf_function *pfunc_cpu_setfreq_high;
  201. static struct pmf_function *pfunc_cpu_setfreq_low;
  202. static struct pmf_function *pfunc_cpu_getfreq;
  203. static struct pmf_function *pfunc_slewing_done;
  204. static int g5_pfunc_switch_freq(int speed_mode)
  205. {
  206. struct pmf_args args;
  207. u32 done = 0;
  208. unsigned long timeout;
  209. int rc;
  210. DBG("g5_pfunc_switch_freq(%d)\n", speed_mode);
  211. /* If frequency is going up, first ramp up the voltage */
  212. if (speed_mode < g5_pmode_cur)
  213. g5_switch_volt(speed_mode);
  214. /* Do it */
  215. if (speed_mode == CPUFREQ_HIGH)
  216. rc = pmf_call_one(pfunc_cpu_setfreq_high, NULL);
  217. else
  218. rc = pmf_call_one(pfunc_cpu_setfreq_low, NULL);
  219. if (rc)
  220. printk(KERN_WARNING "cpufreq: pfunc switch error %d\n", rc);
  221. /* It's an irq GPIO so we should be able to just block here,
  222. * I'll do that later after I've properly tested the IRQ code for
  223. * platform functions
  224. */
  225. timeout = jiffies + HZ/10;
  226. while(!time_after(jiffies, timeout)) {
  227. args.count = 1;
  228. args.u[0].p = &done;
  229. pmf_call_one(pfunc_slewing_done, &args);
  230. if (done)
  231. break;
  232. msleep(1);
  233. }
  234. if (done == 0)
  235. printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
  236. /* If frequency is going down, last ramp the voltage */
  237. if (speed_mode > g5_pmode_cur)
  238. g5_switch_volt(speed_mode);
  239. g5_pmode_cur = speed_mode;
  240. ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
  241. return 0;
  242. }
  243. static int g5_pfunc_query_freq(void)
  244. {
  245. struct pmf_args args;
  246. u32 val = 0;
  247. args.count = 1;
  248. args.u[0].p = &val;
  249. pmf_call_one(pfunc_cpu_getfreq, &args);
  250. return val ? CPUFREQ_HIGH : CPUFREQ_LOW;
  251. }
  252. /*
  253. * Common interface to the cpufreq core
  254. */
  255. static int g5_cpufreq_target(struct cpufreq_policy *policy,
  256. unsigned int target_freq, unsigned int relation)
  257. {
  258. unsigned int newstate = 0;
  259. struct cpufreq_freqs freqs;
  260. int rc;
  261. if (cpufreq_frequency_table_target(policy, g5_cpu_freqs,
  262. target_freq, relation, &newstate))
  263. return -EINVAL;
  264. if (g5_pmode_cur == newstate)
  265. return 0;
  266. mutex_lock(&g5_switch_mutex);
  267. freqs.old = g5_cpu_freqs[g5_pmode_cur].frequency;
  268. freqs.new = g5_cpu_freqs[newstate].frequency;
  269. cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
  270. rc = g5_switch_freq(newstate);
  271. cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
  272. mutex_unlock(&g5_switch_mutex);
  273. return rc;
  274. }
  275. static unsigned int g5_cpufreq_get_speed(unsigned int cpu)
  276. {
  277. return g5_cpu_freqs[g5_pmode_cur].frequency;
  278. }
  279. static int g5_cpufreq_cpu_init(struct cpufreq_policy *policy)
  280. {
  281. policy->cpuinfo.transition_latency = transition_latency;
  282. /* secondary CPUs are tied to the primary one by the
  283. * cpufreq core if in the secondary policy we tell it that
  284. * it actually must be one policy together with all others. */
  285. cpumask_copy(policy->cpus, cpu_online_mask);
  286. return cpufreq_table_validate_and_show(policy, g5_cpu_freqs);
  287. }
  288. static struct cpufreq_driver g5_cpufreq_driver = {
  289. .name = "powermac",
  290. .flags = CPUFREQ_CONST_LOOPS,
  291. .init = g5_cpufreq_cpu_init,
  292. .verify = cpufreq_generic_frequency_table_verify,
  293. .target = g5_cpufreq_target,
  294. .get = g5_cpufreq_get_speed,
  295. .attr = cpufreq_generic_attr,
  296. };
  297. #ifdef CONFIG_PMAC_SMU
  298. static int __init g5_neo2_cpufreq_init(struct device_node *cpunode)
  299. {
  300. unsigned int psize, ssize;
  301. unsigned long max_freq;
  302. char *freq_method, *volt_method;
  303. const u32 *valp;
  304. u32 pvr_hi;
  305. int use_volts_vdnap = 0;
  306. int use_volts_smu = 0;
  307. int rc = -ENODEV;
  308. /* Check supported platforms */
  309. if (of_machine_is_compatible("PowerMac8,1") ||
  310. of_machine_is_compatible("PowerMac8,2") ||
  311. of_machine_is_compatible("PowerMac9,1"))
  312. use_volts_smu = 1;
  313. else if (of_machine_is_compatible("PowerMac11,2"))
  314. use_volts_vdnap = 1;
  315. else
  316. return -ENODEV;
  317. /* Check 970FX for now */
  318. valp = of_get_property(cpunode, "cpu-version", NULL);
  319. if (!valp) {
  320. DBG("No cpu-version property !\n");
  321. goto bail_noprops;
  322. }
  323. pvr_hi = (*valp) >> 16;
  324. if (pvr_hi != 0x3c && pvr_hi != 0x44) {
  325. printk(KERN_ERR "cpufreq: Unsupported CPU version\n");
  326. goto bail_noprops;
  327. }
  328. /* Look for the powertune data in the device-tree */
  329. g5_pmode_data = of_get_property(cpunode, "power-mode-data",&psize);
  330. if (!g5_pmode_data) {
  331. DBG("No power-mode-data !\n");
  332. goto bail_noprops;
  333. }
  334. g5_pmode_max = psize / sizeof(u32) - 1;
  335. if (use_volts_smu) {
  336. const struct smu_sdbp_header *shdr;
  337. /* Look for the FVT table */
  338. shdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
  339. if (!shdr)
  340. goto bail_noprops;
  341. g5_fvt_table = (struct smu_sdbp_fvt *)&shdr[1];
  342. ssize = (shdr->len * sizeof(u32)) - sizeof(*shdr);
  343. g5_fvt_count = ssize / sizeof(*g5_fvt_table);
  344. g5_fvt_cur = 0;
  345. /* Sanity checking */
  346. if (g5_fvt_count < 1 || g5_pmode_max < 1)
  347. goto bail_noprops;
  348. g5_switch_volt = g5_smu_switch_volt;
  349. volt_method = "SMU";
  350. } else if (use_volts_vdnap) {
  351. struct device_node *root;
  352. root = of_find_node_by_path("/");
  353. if (root == NULL) {
  354. printk(KERN_ERR "cpufreq: Can't find root of "
  355. "device tree\n");
  356. goto bail_noprops;
  357. }
  358. pfunc_set_vdnap0 = pmf_find_function(root, "set-vdnap0");
  359. pfunc_vdnap0_complete =
  360. pmf_find_function(root, "slewing-done");
  361. if (pfunc_set_vdnap0 == NULL ||
  362. pfunc_vdnap0_complete == NULL) {
  363. printk(KERN_ERR "cpufreq: Can't find required "
  364. "platform function\n");
  365. goto bail_noprops;
  366. }
  367. g5_switch_volt = g5_vdnap_switch_volt;
  368. volt_method = "GPIO";
  369. } else {
  370. g5_switch_volt = g5_dummy_switch_volt;
  371. volt_method = "none";
  372. }
  373. /*
  374. * From what I see, clock-frequency is always the maximal frequency.
  375. * The current driver can not slew sysclk yet, so we really only deal
  376. * with powertune steps for now. We also only implement full freq and
  377. * half freq in this version. So far, I haven't yet seen a machine
  378. * supporting anything else.
  379. */
  380. valp = of_get_property(cpunode, "clock-frequency", NULL);
  381. if (!valp)
  382. return -ENODEV;
  383. max_freq = (*valp)/1000;
  384. g5_cpu_freqs[0].frequency = max_freq;
  385. g5_cpu_freqs[1].frequency = max_freq/2;
  386. /* Set callbacks */
  387. transition_latency = 12000;
  388. g5_switch_freq = g5_scom_switch_freq;
  389. g5_query_freq = g5_scom_query_freq;
  390. freq_method = "SCOM";
  391. /* Force apply current frequency to make sure everything is in
  392. * sync (voltage is right for example). Firmware may leave us with
  393. * a strange setting ...
  394. */
  395. g5_switch_volt(CPUFREQ_HIGH);
  396. msleep(10);
  397. g5_pmode_cur = -1;
  398. g5_switch_freq(g5_query_freq());
  399. printk(KERN_INFO "Registering G5 CPU frequency driver\n");
  400. printk(KERN_INFO "Frequency method: %s, Voltage method: %s\n",
  401. freq_method, volt_method);
  402. printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
  403. g5_cpu_freqs[1].frequency/1000,
  404. g5_cpu_freqs[0].frequency/1000,
  405. g5_cpu_freqs[g5_pmode_cur].frequency/1000);
  406. rc = cpufreq_register_driver(&g5_cpufreq_driver);
  407. /* We keep the CPU node on hold... hopefully, Apple G5 don't have
  408. * hotplug CPU with a dynamic device-tree ...
  409. */
  410. return rc;
  411. bail_noprops:
  412. of_node_put(cpunode);
  413. return rc;
  414. }
  415. #endif /* CONFIG_PMAC_SMU */
  416. static int __init g5_pm72_cpufreq_init(struct device_node *cpunode)
  417. {
  418. struct device_node *cpuid = NULL, *hwclock = NULL;
  419. const u8 *eeprom = NULL;
  420. const u32 *valp;
  421. u64 max_freq, min_freq, ih, il;
  422. int has_volt = 1, rc = 0;
  423. DBG("cpufreq: Initializing for PowerMac7,2, PowerMac7,3 and"
  424. " RackMac3,1...\n");
  425. /* Lookup the cpuid eeprom node */
  426. cpuid = of_find_node_by_path("/u3@0,f8000000/i2c@f8001000/cpuid@a0");
  427. if (cpuid != NULL)
  428. eeprom = of_get_property(cpuid, "cpuid", NULL);
  429. if (eeprom == NULL) {
  430. printk(KERN_ERR "cpufreq: Can't find cpuid EEPROM !\n");
  431. rc = -ENODEV;
  432. goto bail;
  433. }
  434. /* Lookup the i2c hwclock */
  435. for (hwclock = NULL;
  436. (hwclock = of_find_node_by_name(hwclock, "i2c-hwclock")) != NULL;){
  437. const char *loc = of_get_property(hwclock,
  438. "hwctrl-location", NULL);
  439. if (loc == NULL)
  440. continue;
  441. if (strcmp(loc, "CPU CLOCK"))
  442. continue;
  443. if (!of_get_property(hwclock, "platform-get-frequency", NULL))
  444. continue;
  445. break;
  446. }
  447. if (hwclock == NULL) {
  448. printk(KERN_ERR "cpufreq: Can't find i2c clock chip !\n");
  449. rc = -ENODEV;
  450. goto bail;
  451. }
  452. DBG("cpufreq: i2c clock chip found: %s\n", hwclock->full_name);
  453. /* Now get all the platform functions */
  454. pfunc_cpu_getfreq =
  455. pmf_find_function(hwclock, "get-frequency");
  456. pfunc_cpu_setfreq_high =
  457. pmf_find_function(hwclock, "set-frequency-high");
  458. pfunc_cpu_setfreq_low =
  459. pmf_find_function(hwclock, "set-frequency-low");
  460. pfunc_slewing_done =
  461. pmf_find_function(hwclock, "slewing-done");
  462. pfunc_cpu0_volt_high =
  463. pmf_find_function(hwclock, "set-voltage-high-0");
  464. pfunc_cpu0_volt_low =
  465. pmf_find_function(hwclock, "set-voltage-low-0");
  466. pfunc_cpu1_volt_high =
  467. pmf_find_function(hwclock, "set-voltage-high-1");
  468. pfunc_cpu1_volt_low =
  469. pmf_find_function(hwclock, "set-voltage-low-1");
  470. /* Check we have minimum requirements */
  471. if (pfunc_cpu_getfreq == NULL || pfunc_cpu_setfreq_high == NULL ||
  472. pfunc_cpu_setfreq_low == NULL || pfunc_slewing_done == NULL) {
  473. printk(KERN_ERR "cpufreq: Can't find platform functions !\n");
  474. rc = -ENODEV;
  475. goto bail;
  476. }
  477. /* Check that we have complete sets */
  478. if (pfunc_cpu0_volt_high == NULL || pfunc_cpu0_volt_low == NULL) {
  479. pmf_put_function(pfunc_cpu0_volt_high);
  480. pmf_put_function(pfunc_cpu0_volt_low);
  481. pfunc_cpu0_volt_high = pfunc_cpu0_volt_low = NULL;
  482. has_volt = 0;
  483. }
  484. if (!has_volt ||
  485. pfunc_cpu1_volt_high == NULL || pfunc_cpu1_volt_low == NULL) {
  486. pmf_put_function(pfunc_cpu1_volt_high);
  487. pmf_put_function(pfunc_cpu1_volt_low);
  488. pfunc_cpu1_volt_high = pfunc_cpu1_volt_low = NULL;
  489. }
  490. /* Note: The device tree also contains a "platform-set-values"
  491. * function for which I haven't quite figured out the usage. It
  492. * might have to be called on init and/or wakeup, I'm not too sure
  493. * but things seem to work fine without it so far ...
  494. */
  495. /* Get max frequency from device-tree */
  496. valp = of_get_property(cpunode, "clock-frequency", NULL);
  497. if (!valp) {
  498. printk(KERN_ERR "cpufreq: Can't find CPU frequency !\n");
  499. rc = -ENODEV;
  500. goto bail;
  501. }
  502. max_freq = (*valp)/1000;
  503. /* Now calculate reduced frequency by using the cpuid input freq
  504. * ratio. This requires 64 bits math unless we are willing to lose
  505. * some precision
  506. */
  507. ih = *((u32 *)(eeprom + 0x10));
  508. il = *((u32 *)(eeprom + 0x20));
  509. /* Check for machines with no useful settings */
  510. if (il == ih) {
  511. printk(KERN_WARNING "cpufreq: No low frequency mode available"
  512. " on this model !\n");
  513. rc = -ENODEV;
  514. goto bail;
  515. }
  516. min_freq = 0;
  517. if (ih != 0 && il != 0)
  518. min_freq = (max_freq * il) / ih;
  519. /* Sanity check */
  520. if (min_freq >= max_freq || min_freq < 1000) {
  521. printk(KERN_ERR "cpufreq: Can't calculate low frequency !\n");
  522. rc = -ENXIO;
  523. goto bail;
  524. }
  525. g5_cpu_freqs[0].frequency = max_freq;
  526. g5_cpu_freqs[1].frequency = min_freq;
  527. /* Set callbacks */
  528. transition_latency = CPUFREQ_ETERNAL;
  529. g5_switch_volt = g5_pfunc_switch_volt;
  530. g5_switch_freq = g5_pfunc_switch_freq;
  531. g5_query_freq = g5_pfunc_query_freq;
  532. /* Force apply current frequency to make sure everything is in
  533. * sync (voltage is right for example). Firmware may leave us with
  534. * a strange setting ...
  535. */
  536. g5_switch_volt(CPUFREQ_HIGH);
  537. msleep(10);
  538. g5_pmode_cur = -1;
  539. g5_switch_freq(g5_query_freq());
  540. printk(KERN_INFO "Registering G5 CPU frequency driver\n");
  541. printk(KERN_INFO "Frequency method: i2c/pfunc, "
  542. "Voltage method: %s\n", has_volt ? "i2c/pfunc" : "none");
  543. printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
  544. g5_cpu_freqs[1].frequency/1000,
  545. g5_cpu_freqs[0].frequency/1000,
  546. g5_cpu_freqs[g5_pmode_cur].frequency/1000);
  547. rc = cpufreq_register_driver(&g5_cpufreq_driver);
  548. bail:
  549. if (rc != 0) {
  550. pmf_put_function(pfunc_cpu_getfreq);
  551. pmf_put_function(pfunc_cpu_setfreq_high);
  552. pmf_put_function(pfunc_cpu_setfreq_low);
  553. pmf_put_function(pfunc_slewing_done);
  554. pmf_put_function(pfunc_cpu0_volt_high);
  555. pmf_put_function(pfunc_cpu0_volt_low);
  556. pmf_put_function(pfunc_cpu1_volt_high);
  557. pmf_put_function(pfunc_cpu1_volt_low);
  558. }
  559. of_node_put(hwclock);
  560. of_node_put(cpuid);
  561. of_node_put(cpunode);
  562. return rc;
  563. }
  564. static int __init g5_cpufreq_init(void)
  565. {
  566. struct device_node *cpunode;
  567. int rc = 0;
  568. /* Get first CPU node */
  569. cpunode = of_cpu_device_node_get(0);
  570. if (cpunode == NULL) {
  571. pr_err("cpufreq: Can't find any CPU node\n");
  572. return -ENODEV;
  573. }
  574. if (of_machine_is_compatible("PowerMac7,2") ||
  575. of_machine_is_compatible("PowerMac7,3") ||
  576. of_machine_is_compatible("RackMac3,1"))
  577. rc = g5_pm72_cpufreq_init(cpunode);
  578. #ifdef CONFIG_PMAC_SMU
  579. else
  580. rc = g5_neo2_cpufreq_init(cpunode);
  581. #endif /* CONFIG_PMAC_SMU */
  582. return rc;
  583. }
  584. module_init(g5_cpufreq_init);
  585. MODULE_LICENSE("GPL");