cpufreq_64.c 20 KB

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  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/slab.h>
  20. #include <linux/cpufreq.h>
  21. #include <linux/init.h>
  22. #include <linux/completion.h>
  23. #include <linux/mutex.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. static struct freq_attr* g5_cpu_freqs_attr[] = {
  64. &cpufreq_freq_attr_scaling_available_freqs,
  65. NULL,
  66. };
  67. /* Power mode data is an array of the 32 bits PCR values to use for
  68. * the various frequencies, retrieved from the device-tree
  69. */
  70. static int g5_pmode_cur;
  71. static void (*g5_switch_volt)(int speed_mode);
  72. static int (*g5_switch_freq)(int speed_mode);
  73. static int (*g5_query_freq)(void);
  74. static DEFINE_MUTEX(g5_switch_mutex);
  75. static unsigned long transition_latency;
  76. #ifdef CONFIG_PMAC_SMU
  77. static const u32 *g5_pmode_data;
  78. static int g5_pmode_max;
  79. static struct smu_sdbp_fvt *g5_fvt_table; /* table of op. points */
  80. static int g5_fvt_count; /* number of op. points */
  81. static int g5_fvt_cur; /* current op. point */
  82. /*
  83. * SMU based voltage switching for Neo2 platforms
  84. */
  85. static void g5_smu_switch_volt(int speed_mode)
  86. {
  87. struct smu_simple_cmd cmd;
  88. DECLARE_COMPLETION_ONSTACK(comp);
  89. smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, smu_done_complete,
  90. &comp, 'V', 'S', 'L', 'E', 'W',
  91. 0xff, g5_fvt_cur+1, speed_mode);
  92. wait_for_completion(&comp);
  93. }
  94. /*
  95. * Platform function based voltage/vdnap switching for Neo2
  96. */
  97. static struct pmf_function *pfunc_set_vdnap0;
  98. static struct pmf_function *pfunc_vdnap0_complete;
  99. static void g5_vdnap_switch_volt(int speed_mode)
  100. {
  101. struct pmf_args args;
  102. u32 slew, done = 0;
  103. unsigned long timeout;
  104. slew = (speed_mode == CPUFREQ_LOW) ? 1 : 0;
  105. args.count = 1;
  106. args.u[0].p = &slew;
  107. pmf_call_one(pfunc_set_vdnap0, &args);
  108. /* It's an irq GPIO so we should be able to just block here,
  109. * I'll do that later after I've properly tested the IRQ code for
  110. * platform functions
  111. */
  112. timeout = jiffies + HZ/10;
  113. while(!time_after(jiffies, timeout)) {
  114. args.count = 1;
  115. args.u[0].p = &done;
  116. pmf_call_one(pfunc_vdnap0_complete, &args);
  117. if (done)
  118. break;
  119. msleep(1);
  120. }
  121. if (done == 0)
  122. printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
  123. }
  124. /*
  125. * SCOM based frequency switching for 970FX rev3
  126. */
  127. static int g5_scom_switch_freq(int speed_mode)
  128. {
  129. unsigned long flags;
  130. int to;
  131. /* If frequency is going up, first ramp up the voltage */
  132. if (speed_mode < g5_pmode_cur)
  133. g5_switch_volt(speed_mode);
  134. local_irq_save(flags);
  135. /* Clear PCR high */
  136. scom970_write(SCOM_PCR, 0);
  137. /* Clear PCR low */
  138. scom970_write(SCOM_PCR, PCR_HILO_SELECT | 0);
  139. /* Set PCR low */
  140. scom970_write(SCOM_PCR, PCR_HILO_SELECT |
  141. g5_pmode_data[speed_mode]);
  142. /* Wait for completion */
  143. for (to = 0; to < 10; to++) {
  144. unsigned long psr = scom970_read(SCOM_PSR);
  145. if ((psr & PSR_CMD_RECEIVED) == 0 &&
  146. (((psr >> PSR_CUR_SPEED_SHIFT) ^
  147. (g5_pmode_data[speed_mode] >> PCR_SPEED_SHIFT)) & 0x3)
  148. == 0)
  149. break;
  150. if (psr & PSR_CMD_COMPLETED)
  151. break;
  152. udelay(100);
  153. }
  154. local_irq_restore(flags);
  155. /* If frequency is going down, last ramp the voltage */
  156. if (speed_mode > g5_pmode_cur)
  157. g5_switch_volt(speed_mode);
  158. g5_pmode_cur = speed_mode;
  159. ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
  160. return 0;
  161. }
  162. static int g5_scom_query_freq(void)
  163. {
  164. unsigned long psr = scom970_read(SCOM_PSR);
  165. int i;
  166. for (i = 0; i <= g5_pmode_max; i++)
  167. if ((((psr >> PSR_CUR_SPEED_SHIFT) ^
  168. (g5_pmode_data[i] >> PCR_SPEED_SHIFT)) & 0x3) == 0)
  169. break;
  170. return i;
  171. }
  172. /*
  173. * Fake voltage switching for platforms with missing support
  174. */
  175. static void g5_dummy_switch_volt(int speed_mode)
  176. {
  177. }
  178. #endif /* CONFIG_PMAC_SMU */
  179. /*
  180. * Platform function based voltage switching for PowerMac7,2 & 7,3
  181. */
  182. static struct pmf_function *pfunc_cpu0_volt_high;
  183. static struct pmf_function *pfunc_cpu0_volt_low;
  184. static struct pmf_function *pfunc_cpu1_volt_high;
  185. static struct pmf_function *pfunc_cpu1_volt_low;
  186. static void g5_pfunc_switch_volt(int speed_mode)
  187. {
  188. if (speed_mode == CPUFREQ_HIGH) {
  189. if (pfunc_cpu0_volt_high)
  190. pmf_call_one(pfunc_cpu0_volt_high, NULL);
  191. if (pfunc_cpu1_volt_high)
  192. pmf_call_one(pfunc_cpu1_volt_high, NULL);
  193. } else {
  194. if (pfunc_cpu0_volt_low)
  195. pmf_call_one(pfunc_cpu0_volt_low, NULL);
  196. if (pfunc_cpu1_volt_low)
  197. pmf_call_one(pfunc_cpu1_volt_low, NULL);
  198. }
  199. msleep(10); /* should be faster , to fix */
  200. }
  201. /*
  202. * Platform function based frequency switching for PowerMac7,2 & 7,3
  203. */
  204. static struct pmf_function *pfunc_cpu_setfreq_high;
  205. static struct pmf_function *pfunc_cpu_setfreq_low;
  206. static struct pmf_function *pfunc_cpu_getfreq;
  207. static struct pmf_function *pfunc_slewing_done;;
  208. static int g5_pfunc_switch_freq(int speed_mode)
  209. {
  210. struct pmf_args args;
  211. u32 done = 0;
  212. unsigned long timeout;
  213. int rc;
  214. DBG("g5_pfunc_switch_freq(%d)\n", speed_mode);
  215. /* If frequency is going up, first ramp up the voltage */
  216. if (speed_mode < g5_pmode_cur)
  217. g5_switch_volt(speed_mode);
  218. /* Do it */
  219. if (speed_mode == CPUFREQ_HIGH)
  220. rc = pmf_call_one(pfunc_cpu_setfreq_high, NULL);
  221. else
  222. rc = pmf_call_one(pfunc_cpu_setfreq_low, NULL);
  223. if (rc)
  224. printk(KERN_WARNING "cpufreq: pfunc switch error %d\n", rc);
  225. /* It's an irq GPIO so we should be able to just block here,
  226. * I'll do that later after I've properly tested the IRQ code for
  227. * platform functions
  228. */
  229. timeout = jiffies + HZ/10;
  230. while(!time_after(jiffies, timeout)) {
  231. args.count = 1;
  232. args.u[0].p = &done;
  233. pmf_call_one(pfunc_slewing_done, &args);
  234. if (done)
  235. break;
  236. msleep(1);
  237. }
  238. if (done == 0)
  239. printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
  240. /* If frequency is going down, last ramp the voltage */
  241. if (speed_mode > g5_pmode_cur)
  242. g5_switch_volt(speed_mode);
  243. g5_pmode_cur = speed_mode;
  244. ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
  245. return 0;
  246. }
  247. static int g5_pfunc_query_freq(void)
  248. {
  249. struct pmf_args args;
  250. u32 val = 0;
  251. args.count = 1;
  252. args.u[0].p = &val;
  253. pmf_call_one(pfunc_cpu_getfreq, &args);
  254. return val ? CPUFREQ_HIGH : CPUFREQ_LOW;
  255. }
  256. /*
  257. * Common interface to the cpufreq core
  258. */
  259. static int g5_cpufreq_verify(struct cpufreq_policy *policy)
  260. {
  261. return cpufreq_frequency_table_verify(policy, g5_cpu_freqs);
  262. }
  263. static int g5_cpufreq_target(struct cpufreq_policy *policy,
  264. unsigned int target_freq, unsigned int relation)
  265. {
  266. unsigned int newstate = 0;
  267. struct cpufreq_freqs freqs;
  268. int rc;
  269. if (cpufreq_frequency_table_target(policy, g5_cpu_freqs,
  270. target_freq, relation, &newstate))
  271. return -EINVAL;
  272. if (g5_pmode_cur == newstate)
  273. return 0;
  274. mutex_lock(&g5_switch_mutex);
  275. freqs.old = g5_cpu_freqs[g5_pmode_cur].frequency;
  276. freqs.new = g5_cpu_freqs[newstate].frequency;
  277. freqs.cpu = 0;
  278. cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
  279. rc = g5_switch_freq(newstate);
  280. cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
  281. mutex_unlock(&g5_switch_mutex);
  282. return rc;
  283. }
  284. static unsigned int g5_cpufreq_get_speed(unsigned int cpu)
  285. {
  286. return g5_cpu_freqs[g5_pmode_cur].frequency;
  287. }
  288. static int g5_cpufreq_cpu_init(struct cpufreq_policy *policy)
  289. {
  290. policy->cpuinfo.transition_latency = transition_latency;
  291. policy->cur = g5_cpu_freqs[g5_query_freq()].frequency;
  292. /* secondary CPUs are tied to the primary one by the
  293. * cpufreq core if in the secondary policy we tell it that
  294. * it actually must be one policy together with all others. */
  295. cpumask_copy(policy->cpus, &cpu_online_map);
  296. cpufreq_frequency_table_get_attr(g5_cpu_freqs, policy->cpu);
  297. return cpufreq_frequency_table_cpuinfo(policy,
  298. g5_cpu_freqs);
  299. }
  300. static struct cpufreq_driver g5_cpufreq_driver = {
  301. .name = "powermac",
  302. .owner = THIS_MODULE,
  303. .flags = CPUFREQ_CONST_LOOPS,
  304. .init = g5_cpufreq_cpu_init,
  305. .verify = g5_cpufreq_verify,
  306. .target = g5_cpufreq_target,
  307. .get = g5_cpufreq_get_speed,
  308. .attr = g5_cpu_freqs_attr,
  309. };
  310. #ifdef CONFIG_PMAC_SMU
  311. static int __init g5_neo2_cpufreq_init(struct device_node *cpus)
  312. {
  313. struct device_node *cpunode;
  314. unsigned int psize, ssize;
  315. unsigned long max_freq;
  316. char *freq_method, *volt_method;
  317. const u32 *valp;
  318. u32 pvr_hi;
  319. int use_volts_vdnap = 0;
  320. int use_volts_smu = 0;
  321. int rc = -ENODEV;
  322. /* Check supported platforms */
  323. if (machine_is_compatible("PowerMac8,1") ||
  324. machine_is_compatible("PowerMac8,2") ||
  325. machine_is_compatible("PowerMac9,1"))
  326. use_volts_smu = 1;
  327. else if (machine_is_compatible("PowerMac11,2"))
  328. use_volts_vdnap = 1;
  329. else
  330. return -ENODEV;
  331. /* Get first CPU node */
  332. for (cpunode = NULL;
  333. (cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
  334. const u32 *reg = of_get_property(cpunode, "reg", NULL);
  335. if (reg == NULL || (*reg) != 0)
  336. continue;
  337. if (!strcmp(cpunode->type, "cpu"))
  338. break;
  339. }
  340. if (cpunode == NULL) {
  341. printk(KERN_ERR "cpufreq: Can't find any CPU 0 node\n");
  342. return -ENODEV;
  343. }
  344. /* Check 970FX for now */
  345. valp = of_get_property(cpunode, "cpu-version", NULL);
  346. if (!valp) {
  347. DBG("No cpu-version property !\n");
  348. goto bail_noprops;
  349. }
  350. pvr_hi = (*valp) >> 16;
  351. if (pvr_hi != 0x3c && pvr_hi != 0x44) {
  352. printk(KERN_ERR "cpufreq: Unsupported CPU version\n");
  353. goto bail_noprops;
  354. }
  355. /* Look for the powertune data in the device-tree */
  356. g5_pmode_data = of_get_property(cpunode, "power-mode-data",&psize);
  357. if (!g5_pmode_data) {
  358. DBG("No power-mode-data !\n");
  359. goto bail_noprops;
  360. }
  361. g5_pmode_max = psize / sizeof(u32) - 1;
  362. if (use_volts_smu) {
  363. const struct smu_sdbp_header *shdr;
  364. /* Look for the FVT table */
  365. shdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
  366. if (!shdr)
  367. goto bail_noprops;
  368. g5_fvt_table = (struct smu_sdbp_fvt *)&shdr[1];
  369. ssize = (shdr->len * sizeof(u32)) -
  370. sizeof(struct smu_sdbp_header);
  371. g5_fvt_count = ssize / sizeof(struct smu_sdbp_fvt);
  372. g5_fvt_cur = 0;
  373. /* Sanity checking */
  374. if (g5_fvt_count < 1 || g5_pmode_max < 1)
  375. goto bail_noprops;
  376. g5_switch_volt = g5_smu_switch_volt;
  377. volt_method = "SMU";
  378. } else if (use_volts_vdnap) {
  379. struct device_node *root;
  380. root = of_find_node_by_path("/");
  381. if (root == NULL) {
  382. printk(KERN_ERR "cpufreq: Can't find root of "
  383. "device tree\n");
  384. goto bail_noprops;
  385. }
  386. pfunc_set_vdnap0 = pmf_find_function(root, "set-vdnap0");
  387. pfunc_vdnap0_complete =
  388. pmf_find_function(root, "slewing-done");
  389. if (pfunc_set_vdnap0 == NULL ||
  390. pfunc_vdnap0_complete == NULL) {
  391. printk(KERN_ERR "cpufreq: Can't find required "
  392. "platform function\n");
  393. goto bail_noprops;
  394. }
  395. g5_switch_volt = g5_vdnap_switch_volt;
  396. volt_method = "GPIO";
  397. } else {
  398. g5_switch_volt = g5_dummy_switch_volt;
  399. volt_method = "none";
  400. }
  401. /*
  402. * From what I see, clock-frequency is always the maximal frequency.
  403. * The current driver can not slew sysclk yet, so we really only deal
  404. * with powertune steps for now. We also only implement full freq and
  405. * half freq in this version. So far, I haven't yet seen a machine
  406. * supporting anything else.
  407. */
  408. valp = of_get_property(cpunode, "clock-frequency", NULL);
  409. if (!valp)
  410. return -ENODEV;
  411. max_freq = (*valp)/1000;
  412. g5_cpu_freqs[0].frequency = max_freq;
  413. g5_cpu_freqs[1].frequency = max_freq/2;
  414. /* Set callbacks */
  415. transition_latency = 12000;
  416. g5_switch_freq = g5_scom_switch_freq;
  417. g5_query_freq = g5_scom_query_freq;
  418. freq_method = "SCOM";
  419. /* Force apply current frequency to make sure everything is in
  420. * sync (voltage is right for example). Firmware may leave us with
  421. * a strange setting ...
  422. */
  423. g5_switch_volt(CPUFREQ_HIGH);
  424. msleep(10);
  425. g5_pmode_cur = -1;
  426. g5_switch_freq(g5_query_freq());
  427. printk(KERN_INFO "Registering G5 CPU frequency driver\n");
  428. printk(KERN_INFO "Frequency method: %s, Voltage method: %s\n",
  429. freq_method, volt_method);
  430. printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
  431. g5_cpu_freqs[1].frequency/1000,
  432. g5_cpu_freqs[0].frequency/1000,
  433. g5_cpu_freqs[g5_pmode_cur].frequency/1000);
  434. rc = cpufreq_register_driver(&g5_cpufreq_driver);
  435. /* We keep the CPU node on hold... hopefully, Apple G5 don't have
  436. * hotplug CPU with a dynamic device-tree ...
  437. */
  438. return rc;
  439. bail_noprops:
  440. of_node_put(cpunode);
  441. return rc;
  442. }
  443. #endif /* CONFIG_PMAC_SMU */
  444. static int __init g5_pm72_cpufreq_init(struct device_node *cpus)
  445. {
  446. struct device_node *cpuid = NULL, *hwclock = NULL, *cpunode = NULL;
  447. const u8 *eeprom = NULL;
  448. const u32 *valp;
  449. u64 max_freq, min_freq, ih, il;
  450. int has_volt = 1, rc = 0;
  451. DBG("cpufreq: Initializing for PowerMac7,2, PowerMac7,3 and"
  452. " RackMac3,1...\n");
  453. /* Get first CPU node */
  454. for (cpunode = NULL;
  455. (cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
  456. if (!strcmp(cpunode->type, "cpu"))
  457. break;
  458. }
  459. if (cpunode == NULL) {
  460. printk(KERN_ERR "cpufreq: Can't find any CPU node\n");
  461. return -ENODEV;
  462. }
  463. /* Lookup the cpuid eeprom node */
  464. cpuid = of_find_node_by_path("/u3@0,f8000000/i2c@f8001000/cpuid@a0");
  465. if (cpuid != NULL)
  466. eeprom = of_get_property(cpuid, "cpuid", NULL);
  467. if (eeprom == NULL) {
  468. printk(KERN_ERR "cpufreq: Can't find cpuid EEPROM !\n");
  469. rc = -ENODEV;
  470. goto bail;
  471. }
  472. /* Lookup the i2c hwclock */
  473. for (hwclock = NULL;
  474. (hwclock = of_find_node_by_name(hwclock, "i2c-hwclock")) != NULL;){
  475. const char *loc = of_get_property(hwclock,
  476. "hwctrl-location", NULL);
  477. if (loc == NULL)
  478. continue;
  479. if (strcmp(loc, "CPU CLOCK"))
  480. continue;
  481. if (!of_get_property(hwclock, "platform-get-frequency", NULL))
  482. continue;
  483. break;
  484. }
  485. if (hwclock == NULL) {
  486. printk(KERN_ERR "cpufreq: Can't find i2c clock chip !\n");
  487. rc = -ENODEV;
  488. goto bail;
  489. }
  490. DBG("cpufreq: i2c clock chip found: %s\n", hwclock->full_name);
  491. /* Now get all the platform functions */
  492. pfunc_cpu_getfreq =
  493. pmf_find_function(hwclock, "get-frequency");
  494. pfunc_cpu_setfreq_high =
  495. pmf_find_function(hwclock, "set-frequency-high");
  496. pfunc_cpu_setfreq_low =
  497. pmf_find_function(hwclock, "set-frequency-low");
  498. pfunc_slewing_done =
  499. pmf_find_function(hwclock, "slewing-done");
  500. pfunc_cpu0_volt_high =
  501. pmf_find_function(hwclock, "set-voltage-high-0");
  502. pfunc_cpu0_volt_low =
  503. pmf_find_function(hwclock, "set-voltage-low-0");
  504. pfunc_cpu1_volt_high =
  505. pmf_find_function(hwclock, "set-voltage-high-1");
  506. pfunc_cpu1_volt_low =
  507. pmf_find_function(hwclock, "set-voltage-low-1");
  508. /* Check we have minimum requirements */
  509. if (pfunc_cpu_getfreq == NULL || pfunc_cpu_setfreq_high == NULL ||
  510. pfunc_cpu_setfreq_low == NULL || pfunc_slewing_done == NULL) {
  511. printk(KERN_ERR "cpufreq: Can't find platform functions !\n");
  512. rc = -ENODEV;
  513. goto bail;
  514. }
  515. /* Check that we have complete sets */
  516. if (pfunc_cpu0_volt_high == NULL || pfunc_cpu0_volt_low == NULL) {
  517. pmf_put_function(pfunc_cpu0_volt_high);
  518. pmf_put_function(pfunc_cpu0_volt_low);
  519. pfunc_cpu0_volt_high = pfunc_cpu0_volt_low = NULL;
  520. has_volt = 0;
  521. }
  522. if (!has_volt ||
  523. pfunc_cpu1_volt_high == NULL || pfunc_cpu1_volt_low == NULL) {
  524. pmf_put_function(pfunc_cpu1_volt_high);
  525. pmf_put_function(pfunc_cpu1_volt_low);
  526. pfunc_cpu1_volt_high = pfunc_cpu1_volt_low = NULL;
  527. }
  528. /* Note: The device tree also contains a "platform-set-values"
  529. * function for which I haven't quite figured out the usage. It
  530. * might have to be called on init and/or wakeup, I'm not too sure
  531. * but things seem to work fine without it so far ...
  532. */
  533. /* Get max frequency from device-tree */
  534. valp = of_get_property(cpunode, "clock-frequency", NULL);
  535. if (!valp) {
  536. printk(KERN_ERR "cpufreq: Can't find CPU frequency !\n");
  537. rc = -ENODEV;
  538. goto bail;
  539. }
  540. max_freq = (*valp)/1000;
  541. /* Now calculate reduced frequency by using the cpuid input freq
  542. * ratio. This requires 64 bits math unless we are willing to lose
  543. * some precision
  544. */
  545. ih = *((u32 *)(eeprom + 0x10));
  546. il = *((u32 *)(eeprom + 0x20));
  547. /* Check for machines with no useful settings */
  548. if (il == ih) {
  549. printk(KERN_WARNING "cpufreq: No low frequency mode available"
  550. " on this model !\n");
  551. rc = -ENODEV;
  552. goto bail;
  553. }
  554. min_freq = 0;
  555. if (ih != 0 && il != 0)
  556. min_freq = (max_freq * il) / ih;
  557. /* Sanity check */
  558. if (min_freq >= max_freq || min_freq < 1000) {
  559. printk(KERN_ERR "cpufreq: Can't calculate low frequency !\n");
  560. rc = -ENXIO;
  561. goto bail;
  562. }
  563. g5_cpu_freqs[0].frequency = max_freq;
  564. g5_cpu_freqs[1].frequency = min_freq;
  565. /* Set callbacks */
  566. transition_latency = CPUFREQ_ETERNAL;
  567. g5_switch_volt = g5_pfunc_switch_volt;
  568. g5_switch_freq = g5_pfunc_switch_freq;
  569. g5_query_freq = g5_pfunc_query_freq;
  570. /* Force apply current frequency to make sure everything is in
  571. * sync (voltage is right for example). Firmware may leave us with
  572. * a strange setting ...
  573. */
  574. g5_switch_volt(CPUFREQ_HIGH);
  575. msleep(10);
  576. g5_pmode_cur = -1;
  577. g5_switch_freq(g5_query_freq());
  578. printk(KERN_INFO "Registering G5 CPU frequency driver\n");
  579. printk(KERN_INFO "Frequency method: i2c/pfunc, "
  580. "Voltage method: %s\n", has_volt ? "i2c/pfunc" : "none");
  581. printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
  582. g5_cpu_freqs[1].frequency/1000,
  583. g5_cpu_freqs[0].frequency/1000,
  584. g5_cpu_freqs[g5_pmode_cur].frequency/1000);
  585. rc = cpufreq_register_driver(&g5_cpufreq_driver);
  586. bail:
  587. if (rc != 0) {
  588. pmf_put_function(pfunc_cpu_getfreq);
  589. pmf_put_function(pfunc_cpu_setfreq_high);
  590. pmf_put_function(pfunc_cpu_setfreq_low);
  591. pmf_put_function(pfunc_slewing_done);
  592. pmf_put_function(pfunc_cpu0_volt_high);
  593. pmf_put_function(pfunc_cpu0_volt_low);
  594. pmf_put_function(pfunc_cpu1_volt_high);
  595. pmf_put_function(pfunc_cpu1_volt_low);
  596. }
  597. of_node_put(hwclock);
  598. of_node_put(cpuid);
  599. of_node_put(cpunode);
  600. return rc;
  601. }
  602. static int __init g5_cpufreq_init(void)
  603. {
  604. struct device_node *cpus;
  605. int rc = 0;
  606. cpus = of_find_node_by_path("/cpus");
  607. if (cpus == NULL) {
  608. DBG("No /cpus node !\n");
  609. return -ENODEV;
  610. }
  611. if (machine_is_compatible("PowerMac7,2") ||
  612. machine_is_compatible("PowerMac7,3") ||
  613. machine_is_compatible("RackMac3,1"))
  614. rc = g5_pm72_cpufreq_init(cpus);
  615. #ifdef CONFIG_PMAC_SMU
  616. else
  617. rc = g5_neo2_cpufreq_init(cpus);
  618. #endif /* CONFIG_PMAC_SMU */
  619. of_node_put(cpus);
  620. return rc;
  621. }
  622. module_init(g5_cpufreq_init);
  623. MODULE_LICENSE("GPL");