Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc
[linux-2.6] / drivers / firmware / dcdbas.c
1 /*
2  *  dcdbas.c: Dell Systems Management Base Driver
3  *
4  *  The Dell Systems Management Base Driver provides a sysfs interface for
5  *  systems management software to perform System Management Interrupts (SMIs)
6  *  and Host Control Actions (power cycle or power off after OS shutdown) on
7  *  Dell systems.
8  *
9  *  See Documentation/dcdbas.txt for more information.
10  *
11  *  Copyright (C) 1995-2006 Dell Inc.
12  *
13  *  This program is free software; you can redistribute it and/or modify
14  *  it under the terms of the GNU General Public License v2.0 as published by
15  *  the Free Software Foundation.
16  *
17  *  This program is distributed in the hope that it will be useful,
18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  *  GNU General Public License for more details.
21  */
22
23 #include <linux/platform_device.h>
24 #include <linux/dma-mapping.h>
25 #include <linux/errno.h>
26 #include <linux/init.h>
27 #include <linux/kernel.h>
28 #include <linux/mc146818rtc.h>
29 #include <linux/module.h>
30 #include <linux/reboot.h>
31 #include <linux/sched.h>
32 #include <linux/smp.h>
33 #include <linux/spinlock.h>
34 #include <linux/string.h>
35 #include <linux/types.h>
36 #include <linux/mutex.h>
37 #include <asm/io.h>
38
39 #include "dcdbas.h"
40
41 #define DRIVER_NAME             "dcdbas"
42 #define DRIVER_VERSION          "5.6.0-3.2"
43 #define DRIVER_DESCRIPTION      "Dell Systems Management Base Driver"
44
45 static struct platform_device *dcdbas_pdev;
46
47 static u8 *smi_data_buf;
48 static dma_addr_t smi_data_buf_handle;
49 static unsigned long smi_data_buf_size;
50 static u32 smi_data_buf_phys_addr;
51 static DEFINE_MUTEX(smi_data_lock);
52
53 static unsigned int host_control_action;
54 static unsigned int host_control_smi_type;
55 static unsigned int host_control_on_shutdown;
56
57 /**
58  * smi_data_buf_free: free SMI data buffer
59  */
60 static void smi_data_buf_free(void)
61 {
62         if (!smi_data_buf)
63                 return;
64
65         dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
66                 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
67
68         dma_free_coherent(&dcdbas_pdev->dev, smi_data_buf_size, smi_data_buf,
69                           smi_data_buf_handle);
70         smi_data_buf = NULL;
71         smi_data_buf_handle = 0;
72         smi_data_buf_phys_addr = 0;
73         smi_data_buf_size = 0;
74 }
75
76 /**
77  * smi_data_buf_realloc: grow SMI data buffer if needed
78  */
79 static int smi_data_buf_realloc(unsigned long size)
80 {
81         void *buf;
82         dma_addr_t handle;
83
84         if (smi_data_buf_size >= size)
85                 return 0;
86
87         if (size > MAX_SMI_DATA_BUF_SIZE)
88                 return -EINVAL;
89
90         /* new buffer is needed */
91         buf = dma_alloc_coherent(&dcdbas_pdev->dev, size, &handle, GFP_KERNEL);
92         if (!buf) {
93                 dev_dbg(&dcdbas_pdev->dev,
94                         "%s: failed to allocate memory size %lu\n",
95                         __func__, size);
96                 return -ENOMEM;
97         }
98         /* memory zeroed by dma_alloc_coherent */
99
100         if (smi_data_buf)
101                 memcpy(buf, smi_data_buf, smi_data_buf_size);
102
103         /* free any existing buffer */
104         smi_data_buf_free();
105
106         /* set up new buffer for use */
107         smi_data_buf = buf;
108         smi_data_buf_handle = handle;
109         smi_data_buf_phys_addr = (u32) virt_to_phys(buf);
110         smi_data_buf_size = size;
111
112         dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
113                 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
114
115         return 0;
116 }
117
118 static ssize_t smi_data_buf_phys_addr_show(struct device *dev,
119                                            struct device_attribute *attr,
120                                            char *buf)
121 {
122         return sprintf(buf, "%x\n", smi_data_buf_phys_addr);
123 }
124
125 static ssize_t smi_data_buf_size_show(struct device *dev,
126                                       struct device_attribute *attr,
127                                       char *buf)
128 {
129         return sprintf(buf, "%lu\n", smi_data_buf_size);
130 }
131
132 static ssize_t smi_data_buf_size_store(struct device *dev,
133                                        struct device_attribute *attr,
134                                        const char *buf, size_t count)
135 {
136         unsigned long buf_size;
137         ssize_t ret;
138
139         buf_size = simple_strtoul(buf, NULL, 10);
140
141         /* make sure SMI data buffer is at least buf_size */
142         mutex_lock(&smi_data_lock);
143         ret = smi_data_buf_realloc(buf_size);
144         mutex_unlock(&smi_data_lock);
145         if (ret)
146                 return ret;
147
148         return count;
149 }
150
151 static ssize_t smi_data_read(struct kobject *kobj,
152                              struct bin_attribute *bin_attr,
153                              char *buf, loff_t pos, size_t count)
154 {
155         ssize_t ret;
156
157         mutex_lock(&smi_data_lock);
158         ret = memory_read_from_buffer(buf, count, &pos, smi_data_buf,
159                                         smi_data_buf_size);
160         mutex_unlock(&smi_data_lock);
161         return ret;
162 }
163
164 static ssize_t smi_data_write(struct kobject *kobj,
165                               struct bin_attribute *bin_attr,
166                               char *buf, loff_t pos, size_t count)
167 {
168         ssize_t ret;
169
170         if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
171                 return -EINVAL;
172
173         mutex_lock(&smi_data_lock);
174
175         ret = smi_data_buf_realloc(pos + count);
176         if (ret)
177                 goto out;
178
179         memcpy(smi_data_buf + pos, buf, count);
180         ret = count;
181 out:
182         mutex_unlock(&smi_data_lock);
183         return ret;
184 }
185
186 static ssize_t host_control_action_show(struct device *dev,
187                                         struct device_attribute *attr,
188                                         char *buf)
189 {
190         return sprintf(buf, "%u\n", host_control_action);
191 }
192
193 static ssize_t host_control_action_store(struct device *dev,
194                                          struct device_attribute *attr,
195                                          const char *buf, size_t count)
196 {
197         ssize_t ret;
198
199         /* make sure buffer is available for host control command */
200         mutex_lock(&smi_data_lock);
201         ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
202         mutex_unlock(&smi_data_lock);
203         if (ret)
204                 return ret;
205
206         host_control_action = simple_strtoul(buf, NULL, 10);
207         return count;
208 }
209
210 static ssize_t host_control_smi_type_show(struct device *dev,
211                                           struct device_attribute *attr,
212                                           char *buf)
213 {
214         return sprintf(buf, "%u\n", host_control_smi_type);
215 }
216
217 static ssize_t host_control_smi_type_store(struct device *dev,
218                                            struct device_attribute *attr,
219                                            const char *buf, size_t count)
220 {
221         host_control_smi_type = simple_strtoul(buf, NULL, 10);
222         return count;
223 }
224
225 static ssize_t host_control_on_shutdown_show(struct device *dev,
226                                              struct device_attribute *attr,
227                                              char *buf)
228 {
229         return sprintf(buf, "%u\n", host_control_on_shutdown);
230 }
231
232 static ssize_t host_control_on_shutdown_store(struct device *dev,
233                                               struct device_attribute *attr,
234                                               const char *buf, size_t count)
235 {
236         host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
237         return count;
238 }
239
240 /**
241  * smi_request: generate SMI request
242  *
243  * Called with smi_data_lock.
244  */
245 static int smi_request(struct smi_cmd *smi_cmd)
246 {
247         cpumask_t old_mask;
248         cpumask_of_cpu_ptr(new_mask, 0);
249         int ret = 0;
250
251         if (smi_cmd->magic != SMI_CMD_MAGIC) {
252                 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
253                          __func__);
254                 return -EBADR;
255         }
256
257         /* SMI requires CPU 0 */
258         old_mask = current->cpus_allowed;
259         set_cpus_allowed_ptr(current, new_mask);
260         if (smp_processor_id() != 0) {
261                 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
262                         __func__);
263                 ret = -EBUSY;
264                 goto out;
265         }
266
267         /* generate SMI */
268         asm volatile (
269                 "outb %b0,%w1"
270                 : /* no output args */
271                 : "a" (smi_cmd->command_code),
272                   "d" (smi_cmd->command_address),
273                   "b" (smi_cmd->ebx),
274                   "c" (smi_cmd->ecx)
275                 : "memory"
276         );
277
278 out:
279         set_cpus_allowed_ptr(current, &old_mask);
280         return ret;
281 }
282
283 /**
284  * smi_request_store:
285  *
286  * The valid values are:
287  * 0: zero SMI data buffer
288  * 1: generate calling interface SMI
289  * 2: generate raw SMI
290  *
291  * User application writes smi_cmd to smi_data before telling driver
292  * to generate SMI.
293  */
294 static ssize_t smi_request_store(struct device *dev,
295                                  struct device_attribute *attr,
296                                  const char *buf, size_t count)
297 {
298         struct smi_cmd *smi_cmd;
299         unsigned long val = simple_strtoul(buf, NULL, 10);
300         ssize_t ret;
301
302         mutex_lock(&smi_data_lock);
303
304         if (smi_data_buf_size < sizeof(struct smi_cmd)) {
305                 ret = -ENODEV;
306                 goto out;
307         }
308         smi_cmd = (struct smi_cmd *)smi_data_buf;
309
310         switch (val) {
311         case 2:
312                 /* Raw SMI */
313                 ret = smi_request(smi_cmd);
314                 if (!ret)
315                         ret = count;
316                 break;
317         case 1:
318                 /* Calling Interface SMI */
319                 smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
320                 ret = smi_request(smi_cmd);
321                 if (!ret)
322                         ret = count;
323                 break;
324         case 0:
325                 memset(smi_data_buf, 0, smi_data_buf_size);
326                 ret = count;
327                 break;
328         default:
329                 ret = -EINVAL;
330                 break;
331         }
332
333 out:
334         mutex_unlock(&smi_data_lock);
335         return ret;
336 }
337
338 /**
339  * host_control_smi: generate host control SMI
340  *
341  * Caller must set up the host control command in smi_data_buf.
342  */
343 static int host_control_smi(void)
344 {
345         struct apm_cmd *apm_cmd;
346         u8 *data;
347         unsigned long flags;
348         u32 num_ticks;
349         s8 cmd_status;
350         u8 index;
351
352         apm_cmd = (struct apm_cmd *)smi_data_buf;
353         apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
354
355         switch (host_control_smi_type) {
356         case HC_SMITYPE_TYPE1:
357                 spin_lock_irqsave(&rtc_lock, flags);
358                 /* write SMI data buffer physical address */
359                 data = (u8 *)&smi_data_buf_phys_addr;
360                 for (index = PE1300_CMOS_CMD_STRUCT_PTR;
361                      index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
362                      index++, data++) {
363                         outb(index,
364                              (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
365                         outb(*data,
366                              (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
367                 }
368
369                 /* first set status to -1 as called by spec */
370                 cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
371                 outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
372
373                 /* generate SMM call */
374                 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
375                 spin_unlock_irqrestore(&rtc_lock, flags);
376
377                 /* wait a few to see if it executed */
378                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
379                 while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
380                        == ESM_STATUS_CMD_UNSUCCESSFUL) {
381                         num_ticks--;
382                         if (num_ticks == EXPIRED_TIMER)
383                                 return -ETIME;
384                 }
385                 break;
386
387         case HC_SMITYPE_TYPE2:
388         case HC_SMITYPE_TYPE3:
389                 spin_lock_irqsave(&rtc_lock, flags);
390                 /* write SMI data buffer physical address */
391                 data = (u8 *)&smi_data_buf_phys_addr;
392                 for (index = PE1400_CMOS_CMD_STRUCT_PTR;
393                      index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
394                      index++, data++) {
395                         outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
396                         outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
397                 }
398
399                 /* generate SMM call */
400                 if (host_control_smi_type == HC_SMITYPE_TYPE3)
401                         outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
402                 else
403                         outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
404
405                 /* restore RTC index pointer since it was written to above */
406                 CMOS_READ(RTC_REG_C);
407                 spin_unlock_irqrestore(&rtc_lock, flags);
408
409                 /* read control port back to serialize write */
410                 cmd_status = inb(PE1400_APM_CONTROL_PORT);
411
412                 /* wait a few to see if it executed */
413                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
414                 while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
415                         num_ticks--;
416                         if (num_ticks == EXPIRED_TIMER)
417                                 return -ETIME;
418                 }
419                 break;
420
421         default:
422                 dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
423                         __func__, host_control_smi_type);
424                 return -ENOSYS;
425         }
426
427         return 0;
428 }
429
430 /**
431  * dcdbas_host_control: initiate host control
432  *
433  * This function is called by the driver after the system has
434  * finished shutting down if the user application specified a
435  * host control action to perform on shutdown.  It is safe to
436  * use smi_data_buf at this point because the system has finished
437  * shutting down and no userspace apps are running.
438  */
439 static void dcdbas_host_control(void)
440 {
441         struct apm_cmd *apm_cmd;
442         u8 action;
443
444         if (host_control_action == HC_ACTION_NONE)
445                 return;
446
447         action = host_control_action;
448         host_control_action = HC_ACTION_NONE;
449
450         if (!smi_data_buf) {
451                 dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __func__);
452                 return;
453         }
454
455         if (smi_data_buf_size < sizeof(struct apm_cmd)) {
456                 dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
457                         __func__);
458                 return;
459         }
460
461         apm_cmd = (struct apm_cmd *)smi_data_buf;
462
463         /* power off takes precedence */
464         if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
465                 apm_cmd->command = ESM_APM_POWER_CYCLE;
466                 apm_cmd->reserved = 0;
467                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
468                 host_control_smi();
469         } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
470                 apm_cmd->command = ESM_APM_POWER_CYCLE;
471                 apm_cmd->reserved = 0;
472                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
473                 host_control_smi();
474         }
475 }
476
477 /**
478  * dcdbas_reboot_notify: handle reboot notification for host control
479  */
480 static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
481                                 void *unused)
482 {
483         switch (code) {
484         case SYS_DOWN:
485         case SYS_HALT:
486         case SYS_POWER_OFF:
487                 if (host_control_on_shutdown) {
488                         /* firmware is going to perform host control action */
489                         printk(KERN_WARNING "Please wait for shutdown "
490                                "action to complete...\n");
491                         dcdbas_host_control();
492                 }
493                 break;
494         }
495
496         return NOTIFY_DONE;
497 }
498
499 static struct notifier_block dcdbas_reboot_nb = {
500         .notifier_call = dcdbas_reboot_notify,
501         .next = NULL,
502         .priority = INT_MIN
503 };
504
505 static DCDBAS_BIN_ATTR_RW(smi_data);
506
507 static struct bin_attribute *dcdbas_bin_attrs[] = {
508         &bin_attr_smi_data,
509         NULL
510 };
511
512 static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
513 static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
514 static DCDBAS_DEV_ATTR_WO(smi_request);
515 static DCDBAS_DEV_ATTR_RW(host_control_action);
516 static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
517 static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
518
519 static struct attribute *dcdbas_dev_attrs[] = {
520         &dev_attr_smi_data_buf_size.attr,
521         &dev_attr_smi_data_buf_phys_addr.attr,
522         &dev_attr_smi_request.attr,
523         &dev_attr_host_control_action.attr,
524         &dev_attr_host_control_smi_type.attr,
525         &dev_attr_host_control_on_shutdown.attr,
526         NULL
527 };
528
529 static struct attribute_group dcdbas_attr_group = {
530         .attrs = dcdbas_dev_attrs,
531 };
532
533 static int __devinit dcdbas_probe(struct platform_device *dev)
534 {
535         int i, error;
536
537         host_control_action = HC_ACTION_NONE;
538         host_control_smi_type = HC_SMITYPE_NONE;
539
540         /*
541          * BIOS SMI calls require buffer addresses be in 32-bit address space.
542          * This is done by setting the DMA mask below.
543          */
544         dcdbas_pdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
545         dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
546
547         error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
548         if (error)
549                 return error;
550
551         for (i = 0; dcdbas_bin_attrs[i]; i++) {
552                 error = sysfs_create_bin_file(&dev->dev.kobj,
553                                               dcdbas_bin_attrs[i]);
554                 if (error) {
555                         while (--i >= 0)
556                                 sysfs_remove_bin_file(&dev->dev.kobj,
557                                                       dcdbas_bin_attrs[i]);
558                         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
559                         return error;
560                 }
561         }
562
563         register_reboot_notifier(&dcdbas_reboot_nb);
564
565         dev_info(&dev->dev, "%s (version %s)\n",
566                  DRIVER_DESCRIPTION, DRIVER_VERSION);
567
568         return 0;
569 }
570
571 static int __devexit dcdbas_remove(struct platform_device *dev)
572 {
573         int i;
574
575         unregister_reboot_notifier(&dcdbas_reboot_nb);
576         for (i = 0; dcdbas_bin_attrs[i]; i++)
577                 sysfs_remove_bin_file(&dev->dev.kobj, dcdbas_bin_attrs[i]);
578         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
579
580         return 0;
581 }
582
583 static struct platform_driver dcdbas_driver = {
584         .driver         = {
585                 .name   = DRIVER_NAME,
586                 .owner  = THIS_MODULE,
587         },
588         .probe          = dcdbas_probe,
589         .remove         = __devexit_p(dcdbas_remove),
590 };
591
592 /**
593  * dcdbas_init: initialize driver
594  */
595 static int __init dcdbas_init(void)
596 {
597         int error;
598
599         error = platform_driver_register(&dcdbas_driver);
600         if (error)
601                 return error;
602
603         dcdbas_pdev = platform_device_alloc(DRIVER_NAME, -1);
604         if (!dcdbas_pdev) {
605                 error = -ENOMEM;
606                 goto err_unregister_driver;
607         }
608
609         error = platform_device_add(dcdbas_pdev);
610         if (error)
611                 goto err_free_device;
612
613         return 0;
614
615  err_free_device:
616         platform_device_put(dcdbas_pdev);
617  err_unregister_driver:
618         platform_driver_unregister(&dcdbas_driver);
619         return error;
620 }
621
622 /**
623  * dcdbas_exit: perform driver cleanup
624  */
625 static void __exit dcdbas_exit(void)
626 {
627         /*
628          * make sure functions that use dcdbas_pdev are called
629          * before platform_device_unregister
630          */
631         unregister_reboot_notifier(&dcdbas_reboot_nb);
632         smi_data_buf_free();
633         platform_device_unregister(dcdbas_pdev);
634         platform_driver_unregister(&dcdbas_driver);
635
636         /*
637          * We have to free the buffer here instead of dcdbas_remove
638          * because only in module exit function we can be sure that
639          * all sysfs attributes belonging to this module have been
640          * released.
641          */
642         smi_data_buf_free();
643 }
644
645 module_init(dcdbas_init);
646 module_exit(dcdbas_exit);
647
648 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
649 MODULE_VERSION(DRIVER_VERSION);
650 MODULE_AUTHOR("Dell Inc.");
651 MODULE_LICENSE("GPL");
652 /* Any System or BIOS claiming to be by Dell */
653 MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");