2 * i8k.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
3 * See http://www.debian.org/~dz/i8k/ for more information
4 * and for latest version of this driver.
6 * Copyright (C) 2001 Massimo Dal Zotto <dz@debian.org>
9 * Copyright (C) 2011 Jean Delvare <khali@linux-fr.org>
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the
13 * Free Software Foundation; either version 2, or (at your option) any
16 * This program is distributed in the hope that it will be useful, but
17 * WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * General Public License for more details.
22 #include <linux/module.h>
23 #include <linux/types.h>
24 #include <linux/init.h>
25 #include <linux/proc_fs.h>
26 #include <linux/seq_file.h>
27 #include <linux/dmi.h>
28 #include <linux/capability.h>
29 #include <linux/mutex.h>
30 #include <linux/hwmon.h>
31 #include <linux/hwmon-sysfs.h>
32 #include <asm/uaccess.h>
35 #include <linux/i8k.h>
37 #define I8K_VERSION "1.14 21/02/2005"
39 #define I8K_SMM_FN_STATUS 0x0025
40 #define I8K_SMM_POWER_STATUS 0x0069
41 #define I8K_SMM_SET_FAN 0x01a3
42 #define I8K_SMM_GET_FAN 0x00a3
43 #define I8K_SMM_GET_SPEED 0x02a3
44 #define I8K_SMM_GET_TEMP 0x10a3
45 #define I8K_SMM_GET_DELL_SIG1 0xfea3
46 #define I8K_SMM_GET_DELL_SIG2 0xffa3
47 #define I8K_SMM_BIOS_VERSION 0x00a6
49 #define I8K_FAN_MULT 30
50 #define I8K_MAX_TEMP 127
52 #define I8K_FN_NONE 0x00
53 #define I8K_FN_UP 0x01
54 #define I8K_FN_DOWN 0x02
55 #define I8K_FN_MUTE 0x04
56 #define I8K_FN_MASK 0x07
57 #define I8K_FN_SHIFT 8
59 #define I8K_POWER_AC 0x05
60 #define I8K_POWER_BATTERY 0x01
62 #define I8K_TEMPERATURE_BUG 1
64 static DEFINE_MUTEX(i8k_mutex);
65 static char bios_version[4];
66 static struct device *i8k_hwmon_dev;
68 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
69 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
70 MODULE_LICENSE("GPL");
73 module_param(force, bool, 0);
74 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
76 static int ignore_dmi;
77 module_param(ignore_dmi, bool, 0);
78 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
80 static int restricted;
81 module_param(restricted, bool, 0);
82 MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
84 static int power_status;
85 module_param(power_status, bool, 0600);
86 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
88 static int fan_mult = I8K_FAN_MULT;
89 module_param(fan_mult, int, 0);
90 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");
92 static int i8k_open_fs(struct inode *inode, struct file *file);
93 static long i8k_ioctl(struct file *, unsigned int, unsigned long);
95 static const struct file_operations i8k_fops = {
100 .release = single_release,
101 .unlocked_ioctl = i8k_ioctl,
106 unsigned int ebx __attribute__ ((packed));
107 unsigned int ecx __attribute__ ((packed));
108 unsigned int edx __attribute__ ((packed));
109 unsigned int esi __attribute__ ((packed));
110 unsigned int edi __attribute__ ((packed));
113 static inline const char *i8k_get_dmi_data(int field)
115 const char *dmi_data = dmi_get_system_info(field);
117 return dmi_data && *dmi_data ? dmi_data : "?";
121 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
123 static int i8k_smm(struct smm_regs *regs)
128 #if defined(CONFIG_X86_64)
129 asm volatile("pushq %%rax\n\t"
130 "movl 0(%%rax),%%edx\n\t"
132 "movl 4(%%rax),%%ebx\n\t"
133 "movl 8(%%rax),%%ecx\n\t"
134 "movl 12(%%rax),%%edx\n\t"
135 "movl 16(%%rax),%%esi\n\t"
136 "movl 20(%%rax),%%edi\n\t"
140 "xchgq %%rax,(%%rsp)\n\t"
141 "movl %%ebx,4(%%rax)\n\t"
142 "movl %%ecx,8(%%rax)\n\t"
143 "movl %%edx,12(%%rax)\n\t"
144 "movl %%esi,16(%%rax)\n\t"
145 "movl %%edi,20(%%rax)\n\t"
147 "movl %%edx,0(%%rax)\n\t"
153 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
155 asm volatile("pushl %%eax\n\t"
156 "movl 0(%%eax),%%edx\n\t"
158 "movl 4(%%eax),%%ebx\n\t"
159 "movl 8(%%eax),%%ecx\n\t"
160 "movl 12(%%eax),%%edx\n\t"
161 "movl 16(%%eax),%%esi\n\t"
162 "movl 20(%%eax),%%edi\n\t"
166 "xchgl %%eax,(%%esp)\n\t"
167 "movl %%ebx,4(%%eax)\n\t"
168 "movl %%ecx,8(%%eax)\n\t"
169 "movl %%edx,12(%%eax)\n\t"
170 "movl %%esi,16(%%eax)\n\t"
171 "movl %%edi,20(%%eax)\n\t"
173 "movl %%edx,0(%%eax)\n\t"
179 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
181 if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
188 * Read the bios version. Return the version as an integer corresponding
189 * to the ascii value, for example "A17" is returned as 0x00413137.
191 static int i8k_get_bios_version(void)
193 struct smm_regs regs = { .eax = I8K_SMM_BIOS_VERSION, };
195 return i8k_smm(®s) ? : regs.eax;
199 * Read the Fn key status.
201 static int i8k_get_fn_status(void)
203 struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
206 if ((rc = i8k_smm(®s)) < 0)
209 switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
222 * Read the power status.
224 static int i8k_get_power_status(void)
226 struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
229 if ((rc = i8k_smm(®s)) < 0)
232 return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
236 * Read the fan status.
238 static int i8k_get_fan_status(int fan)
240 struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
242 regs.ebx = fan & 0xff;
243 return i8k_smm(®s) ? : regs.eax & 0xff;
247 * Read the fan speed in RPM.
249 static int i8k_get_fan_speed(int fan)
251 struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
253 regs.ebx = fan & 0xff;
254 return i8k_smm(®s) ? : (regs.eax & 0xffff) * fan_mult;
258 * Set the fan speed (off, low, high). Returns the new fan status.
260 static int i8k_set_fan(int fan, int speed)
262 struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
264 speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
265 regs.ebx = (fan & 0xff) | (speed << 8);
267 return i8k_smm(®s) ? : i8k_get_fan_status(fan);
271 * Read the cpu temperature.
273 static int i8k_get_temp(int sensor)
275 struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP, };
279 #ifdef I8K_TEMPERATURE_BUG
282 regs.ebx = sensor & 0xff;
283 if ((rc = i8k_smm(®s)) < 0)
286 temp = regs.eax & 0xff;
288 #ifdef I8K_TEMPERATURE_BUG
290 * Sometimes the temperature sensor returns 0x99, which is out of range.
291 * In this case we return (once) the previous cached value. For example:
292 # 1003655137 00000058 00005a4b
293 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
294 # 1003655139 00000054 00005c52
296 if (temp > I8K_MAX_TEMP) {
307 static int i8k_get_dell_signature(int req_fn)
309 struct smm_regs regs = { .eax = req_fn, };
312 if ((rc = i8k_smm(®s)) < 0)
315 return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
319 i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
323 unsigned char buff[16];
324 int __user *argp = (int __user *)arg;
330 case I8K_BIOS_VERSION:
331 val = i8k_get_bios_version();
336 strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL), sizeof(buff));
340 val = i8k_get_fn_status();
343 case I8K_POWER_STATUS:
344 val = i8k_get_power_status();
348 val = i8k_get_temp(0);
352 if (copy_from_user(&val, argp, sizeof(int)))
355 val = i8k_get_fan_speed(val);
359 if (copy_from_user(&val, argp, sizeof(int)))
362 val = i8k_get_fan_status(val);
366 if (restricted && !capable(CAP_SYS_ADMIN))
369 if (copy_from_user(&val, argp, sizeof(int)))
372 if (copy_from_user(&speed, argp + 1, sizeof(int)))
375 val = i8k_set_fan(val, speed);
386 case I8K_BIOS_VERSION:
387 if (copy_to_user(argp, &val, 4))
392 if (copy_to_user(argp, buff, 16))
397 if (copy_to_user(argp, &val, sizeof(int)))
406 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
410 mutex_lock(&i8k_mutex);
411 ret = i8k_ioctl_unlocked(fp, cmd, arg);
412 mutex_unlock(&i8k_mutex);
418 * Print the information for /proc/i8k.
420 static int i8k_proc_show(struct seq_file *seq, void *offset)
422 int fn_key, cpu_temp, ac_power;
423 int left_fan, right_fan, left_speed, right_speed;
425 cpu_temp = i8k_get_temp(0); /* 11100 µs */
426 left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 µs */
427 right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 µs */
428 left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 µs */
429 right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 µs */
430 fn_key = i8k_get_fn_status(); /* 750 µs */
432 ac_power = i8k_get_power_status(); /* 14700 µs */
439 * 1) Format version (this will change if format changes)
444 * 6) Right fan status
450 return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
453 i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
455 left_fan, right_fan, left_speed, right_speed,
459 static int i8k_open_fs(struct inode *inode, struct file *file)
461 return single_open(file, i8k_proc_show, NULL);
469 static ssize_t i8k_hwmon_show_temp(struct device *dev,
470 struct device_attribute *devattr,
475 cpu_temp = i8k_get_temp(0);
478 return sprintf(buf, "%d\n", cpu_temp * 1000);
481 static ssize_t i8k_hwmon_show_fan(struct device *dev,
482 struct device_attribute *devattr,
485 int index = to_sensor_dev_attr(devattr)->index;
488 fan_speed = i8k_get_fan_speed(index);
491 return sprintf(buf, "%d\n", fan_speed);
494 static ssize_t i8k_hwmon_show_label(struct device *dev,
495 struct device_attribute *devattr,
498 static const char *labels[4] = {
504 int index = to_sensor_dev_attr(devattr)->index;
506 return sprintf(buf, "%s\n", labels[index]);
509 static DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL);
510 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
512 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
514 static SENSOR_DEVICE_ATTR(name, S_IRUGO, i8k_hwmon_show_label, NULL, 0);
515 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 1);
516 static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 2);
517 static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_label, NULL, 3);
519 static void i8k_hwmon_remove_files(struct device *dev)
521 device_remove_file(dev, &dev_attr_temp1_input);
522 device_remove_file(dev, &sensor_dev_attr_fan1_input.dev_attr);
523 device_remove_file(dev, &sensor_dev_attr_fan2_input.dev_attr);
524 device_remove_file(dev, &sensor_dev_attr_temp1_label.dev_attr);
525 device_remove_file(dev, &sensor_dev_attr_fan1_label.dev_attr);
526 device_remove_file(dev, &sensor_dev_attr_fan2_label.dev_attr);
527 device_remove_file(dev, &sensor_dev_attr_name.dev_attr);
530 static int __init i8k_init_hwmon(void)
534 i8k_hwmon_dev = hwmon_device_register(NULL);
535 if (IS_ERR(i8k_hwmon_dev)) {
536 err = PTR_ERR(i8k_hwmon_dev);
537 i8k_hwmon_dev = NULL;
538 printk(KERN_ERR "i8k: hwmon registration failed (%d)\n", err);
542 /* Required name attribute */
543 err = device_create_file(i8k_hwmon_dev,
544 &sensor_dev_attr_name.dev_attr);
546 goto exit_unregister;
548 /* CPU temperature attributes, if temperature reading is OK */
549 err = i8k_get_temp(0);
551 dev_dbg(i8k_hwmon_dev,
552 "Not creating temperature attributes (%d)\n", err);
554 err = device_create_file(i8k_hwmon_dev, &dev_attr_temp1_input);
556 goto exit_remove_files;
557 err = device_create_file(i8k_hwmon_dev,
558 &sensor_dev_attr_temp1_label.dev_attr);
560 goto exit_remove_files;
563 /* Left fan attributes, if left fan is present */
564 err = i8k_get_fan_status(I8K_FAN_LEFT);
566 dev_dbg(i8k_hwmon_dev,
567 "Not creating %s fan attributes (%d)\n", "left", err);
569 err = device_create_file(i8k_hwmon_dev,
570 &sensor_dev_attr_fan1_input.dev_attr);
572 goto exit_remove_files;
573 err = device_create_file(i8k_hwmon_dev,
574 &sensor_dev_attr_fan1_label.dev_attr);
576 goto exit_remove_files;
579 /* Right fan attributes, if right fan is present */
580 err = i8k_get_fan_status(I8K_FAN_RIGHT);
582 dev_dbg(i8k_hwmon_dev,
583 "Not creating %s fan attributes (%d)\n", "right", err);
585 err = device_create_file(i8k_hwmon_dev,
586 &sensor_dev_attr_fan2_input.dev_attr);
588 goto exit_remove_files;
589 err = device_create_file(i8k_hwmon_dev,
590 &sensor_dev_attr_fan2_label.dev_attr);
592 goto exit_remove_files;
598 i8k_hwmon_remove_files(i8k_hwmon_dev);
600 hwmon_device_unregister(i8k_hwmon_dev);
604 static void __exit i8k_exit_hwmon(void)
606 i8k_hwmon_remove_files(i8k_hwmon_dev);
607 hwmon_device_unregister(i8k_hwmon_dev);
610 static struct dmi_system_id __initdata i8k_dmi_table[] = {
612 .ident = "Dell Inspiron",
614 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
615 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
619 .ident = "Dell Latitude",
621 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
622 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
626 .ident = "Dell Inspiron 2",
628 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
629 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
633 .ident = "Dell Latitude 2",
635 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
636 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
639 { /* UK Inspiron 6400 */
640 .ident = "Dell Inspiron 3",
642 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
643 DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
647 .ident = "Dell Inspiron 3",
649 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
650 DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
654 .ident = "Dell Precision",
656 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
657 DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
661 .ident = "Dell Vostro",
663 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
664 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
671 * Probe for the presence of a supported laptop.
673 static int __init i8k_probe(void)
679 * Get DMI information
681 if (!dmi_check_system(i8k_dmi_table)) {
682 if (!ignore_dmi && !force)
685 printk(KERN_INFO "i8k: not running on a supported Dell system.\n");
686 printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n",
687 i8k_get_dmi_data(DMI_SYS_VENDOR),
688 i8k_get_dmi_data(DMI_PRODUCT_NAME),
689 i8k_get_dmi_data(DMI_BIOS_VERSION));
692 strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION), sizeof(bios_version));
695 * Get SMM Dell signature
697 if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
698 i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
699 printk(KERN_ERR "i8k: unable to get SMM Dell signature\n");
705 * Get SMM BIOS version.
707 version = i8k_get_bios_version();
709 printk(KERN_WARNING "i8k: unable to get SMM BIOS version\n");
711 buff[0] = (version >> 16) & 0xff;
712 buff[1] = (version >> 8) & 0xff;
713 buff[2] = (version) & 0xff;
716 * If DMI BIOS version is unknown use SMM BIOS version.
718 if (!dmi_get_system_info(DMI_BIOS_VERSION))
719 strlcpy(bios_version, buff, sizeof(bios_version));
722 * Check if the two versions match.
724 if (strncmp(buff, bios_version, sizeof(bios_version)) != 0)
725 printk(KERN_WARNING "i8k: BIOS version mismatch: %s != %s\n",
732 static int __init i8k_init(void)
734 struct proc_dir_entry *proc_i8k;
737 /* Are we running on an supported laptop? */
741 /* Register the proc entry */
742 proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
746 err = i8k_init_hwmon();
748 goto exit_remove_proc;
751 "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
757 remove_proc_entry("i8k", NULL);
761 static void __exit i8k_exit(void)
764 remove_proc_entry("i8k", NULL);
767 module_init(i8k_init);
768 module_exit(i8k_exit);