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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 #include <linux/module.h>
25 #include <linux/types.h>
26 #include <linux/init.h>
27 #include <linux/proc_fs.h>
28 #include <linux/seq_file.h>
29 #include <linux/dmi.h>
30 #include <linux/capability.h>
31 #include <linux/mutex.h>
32 #include <linux/hwmon.h>
33 #include <linux/hwmon-sysfs.h>
34 #include <linux/uaccess.h>
37 #include <linux/i8k.h>
39 #define I8K_VERSION "1.14 21/02/2005"
41 #define I8K_SMM_FN_STATUS 0x0025
42 #define I8K_SMM_POWER_STATUS 0x0069
43 #define I8K_SMM_SET_FAN 0x01a3
44 #define I8K_SMM_GET_FAN 0x00a3
45 #define I8K_SMM_GET_SPEED 0x02a3
46 #define I8K_SMM_GET_TEMP 0x10a3
47 #define I8K_SMM_GET_DELL_SIG1 0xfea3
48 #define I8K_SMM_GET_DELL_SIG2 0xffa3
49 #define I8K_SMM_BIOS_VERSION 0x00a6
51 #define I8K_FAN_MULT 30
52 #define I8K_MAX_TEMP 127
54 #define I8K_FN_NONE 0x00
55 #define I8K_FN_UP 0x01
56 #define I8K_FN_DOWN 0x02
57 #define I8K_FN_MUTE 0x04
58 #define I8K_FN_MASK 0x07
59 #define I8K_FN_SHIFT 8
61 #define I8K_POWER_AC 0x05
62 #define I8K_POWER_BATTERY 0x01
64 #define I8K_TEMPERATURE_BUG 1
66 static DEFINE_MUTEX(i8k_mutex);
67 static char bios_version[4];
68 static struct device *i8k_hwmon_dev;
70 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
71 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
72 MODULE_LICENSE("GPL");
75 module_param(force, bool, 0);
76 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
78 static bool ignore_dmi;
79 module_param(ignore_dmi, bool, 0);
80 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
82 static bool restricted;
83 module_param(restricted, bool, 0);
84 MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
86 static bool power_status;
87 module_param(power_status, bool, 0600);
88 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
90 static int fan_mult = I8K_FAN_MULT;
91 module_param(fan_mult, int, 0);
92 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");
94 static int i8k_open_fs(struct inode *inode, struct file *file);
95 static long i8k_ioctl(struct file *, unsigned int, unsigned long);
97 static const struct file_operations i8k_fops = {
102 .release = single_release,
103 .unlocked_ioctl = i8k_ioctl,
108 unsigned int ebx __packed;
109 unsigned int ecx __packed;
110 unsigned int edx __packed;
111 unsigned int esi __packed;
112 unsigned int edi __packed;
115 static inline const char *i8k_get_dmi_data(int field)
117 const char *dmi_data = dmi_get_system_info(field);
119 return dmi_data && *dmi_data ? dmi_data : "?";
123 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
125 static int i8k_smm(struct smm_regs *regs)
130 #if defined(CONFIG_X86_64)
131 asm volatile("pushq %%rax\n\t"
132 "movl 0(%%rax),%%edx\n\t"
134 "movl 4(%%rax),%%ebx\n\t"
135 "movl 8(%%rax),%%ecx\n\t"
136 "movl 12(%%rax),%%edx\n\t"
137 "movl 16(%%rax),%%esi\n\t"
138 "movl 20(%%rax),%%edi\n\t"
142 "xchgq %%rax,(%%rsp)\n\t"
143 "movl %%ebx,4(%%rax)\n\t"
144 "movl %%ecx,8(%%rax)\n\t"
145 "movl %%edx,12(%%rax)\n\t"
146 "movl %%esi,16(%%rax)\n\t"
147 "movl %%edi,20(%%rax)\n\t"
149 "movl %%edx,0(%%rax)\n\t"
155 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
157 asm volatile("pushl %%eax\n\t"
158 "movl 0(%%eax),%%edx\n\t"
160 "movl 4(%%eax),%%ebx\n\t"
161 "movl 8(%%eax),%%ecx\n\t"
162 "movl 12(%%eax),%%edx\n\t"
163 "movl 16(%%eax),%%esi\n\t"
164 "movl 20(%%eax),%%edi\n\t"
168 "xchgl %%eax,(%%esp)\n\t"
169 "movl %%ebx,4(%%eax)\n\t"
170 "movl %%ecx,8(%%eax)\n\t"
171 "movl %%edx,12(%%eax)\n\t"
172 "movl %%esi,16(%%eax)\n\t"
173 "movl %%edi,20(%%eax)\n\t"
175 "movl %%edx,0(%%eax)\n\t"
181 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
183 if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
190 * Read the bios version. Return the version as an integer corresponding
191 * to the ascii value, for example "A17" is returned as 0x00413137.
193 static int i8k_get_bios_version(void)
195 struct smm_regs regs = { .eax = I8K_SMM_BIOS_VERSION, };
197 return i8k_smm(®s) ? : regs.eax;
201 * Read the Fn key status.
203 static int i8k_get_fn_status(void)
205 struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
212 switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
225 * Read the power status.
227 static int i8k_get_power_status(void)
229 struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
236 return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
240 * Read the fan status.
242 static int i8k_get_fan_status(int fan)
244 struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
246 regs.ebx = fan & 0xff;
247 return i8k_smm(®s) ? : regs.eax & 0xff;
251 * Read the fan speed in RPM.
253 static int i8k_get_fan_speed(int fan)
255 struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
257 regs.ebx = fan & 0xff;
258 return i8k_smm(®s) ? : (regs.eax & 0xffff) * fan_mult;
262 * Set the fan speed (off, low, high). Returns the new fan status.
264 static int i8k_set_fan(int fan, int speed)
266 struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
268 speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
269 regs.ebx = (fan & 0xff) | (speed << 8);
271 return i8k_smm(®s) ? : i8k_get_fan_status(fan);
275 * Read the cpu temperature.
277 static int i8k_get_temp(int sensor)
279 struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP, };
283 #ifdef I8K_TEMPERATURE_BUG
286 regs.ebx = sensor & 0xff;
291 temp = regs.eax & 0xff;
293 #ifdef I8K_TEMPERATURE_BUG
295 * Sometimes the temperature sensor returns 0x99, which is out of range.
296 * In this case we return (once) the previous cached value. For example:
297 # 1003655137 00000058 00005a4b
298 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
299 # 1003655139 00000054 00005c52
301 if (temp > I8K_MAX_TEMP) {
312 static int i8k_get_dell_signature(int req_fn)
314 struct smm_regs regs = { .eax = req_fn, };
321 return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
325 i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
329 unsigned char buff[16];
330 int __user *argp = (int __user *)arg;
336 case I8K_BIOS_VERSION:
337 val = i8k_get_bios_version();
342 strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
347 val = i8k_get_fn_status();
350 case I8K_POWER_STATUS:
351 val = i8k_get_power_status();
355 val = i8k_get_temp(0);
359 if (copy_from_user(&val, argp, sizeof(int)))
362 val = i8k_get_fan_speed(val);
366 if (copy_from_user(&val, argp, sizeof(int)))
369 val = i8k_get_fan_status(val);
373 if (restricted && !capable(CAP_SYS_ADMIN))
376 if (copy_from_user(&val, argp, sizeof(int)))
379 if (copy_from_user(&speed, argp + 1, sizeof(int)))
382 val = i8k_set_fan(val, speed);
393 case I8K_BIOS_VERSION:
394 if (copy_to_user(argp, &val, 4))
399 if (copy_to_user(argp, buff, 16))
404 if (copy_to_user(argp, &val, sizeof(int)))
413 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
417 mutex_lock(&i8k_mutex);
418 ret = i8k_ioctl_unlocked(fp, cmd, arg);
419 mutex_unlock(&i8k_mutex);
425 * Print the information for /proc/i8k.
427 static int i8k_proc_show(struct seq_file *seq, void *offset)
429 int fn_key, cpu_temp, ac_power;
430 int left_fan, right_fan, left_speed, right_speed;
432 cpu_temp = i8k_get_temp(0); /* 11100 µs */
433 left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 µs */
434 right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 µs */
435 left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 µs */
436 right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 µs */
437 fn_key = i8k_get_fn_status(); /* 750 µs */
439 ac_power = i8k_get_power_status(); /* 14700 µs */
446 * 1) Format version (this will change if format changes)
451 * 6) Right fan status
457 return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
460 i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
462 left_fan, right_fan, left_speed, right_speed,
466 static int i8k_open_fs(struct inode *inode, struct file *file)
468 return single_open(file, i8k_proc_show, NULL);
476 static ssize_t i8k_hwmon_show_temp(struct device *dev,
477 struct device_attribute *devattr,
482 cpu_temp = i8k_get_temp(0);
485 return sprintf(buf, "%d\n", cpu_temp * 1000);
488 static ssize_t i8k_hwmon_show_fan(struct device *dev,
489 struct device_attribute *devattr,
492 int index = to_sensor_dev_attr(devattr)->index;
495 fan_speed = i8k_get_fan_speed(index);
498 return sprintf(buf, "%d\n", fan_speed);
501 static ssize_t i8k_hwmon_show_label(struct device *dev,
502 struct device_attribute *devattr,
505 static const char *labels[4] = {
511 int index = to_sensor_dev_attr(devattr)->index;
513 return sprintf(buf, "%s\n", labels[index]);
516 static DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL);
517 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
519 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
521 static SENSOR_DEVICE_ATTR(name, S_IRUGO, i8k_hwmon_show_label, NULL, 0);
522 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 1);
523 static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 2);
524 static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_label, NULL, 3);
526 static void i8k_hwmon_remove_files(struct device *dev)
528 device_remove_file(dev, &dev_attr_temp1_input);
529 device_remove_file(dev, &sensor_dev_attr_fan1_input.dev_attr);
530 device_remove_file(dev, &sensor_dev_attr_fan2_input.dev_attr);
531 device_remove_file(dev, &sensor_dev_attr_temp1_label.dev_attr);
532 device_remove_file(dev, &sensor_dev_attr_fan1_label.dev_attr);
533 device_remove_file(dev, &sensor_dev_attr_fan2_label.dev_attr);
534 device_remove_file(dev, &sensor_dev_attr_name.dev_attr);
537 static int __init i8k_init_hwmon(void)
541 i8k_hwmon_dev = hwmon_device_register(NULL);
542 if (IS_ERR(i8k_hwmon_dev)) {
543 err = PTR_ERR(i8k_hwmon_dev);
544 i8k_hwmon_dev = NULL;
545 pr_err("hwmon registration failed (%d)\n", err);
549 /* Required name attribute */
550 err = device_create_file(i8k_hwmon_dev,
551 &sensor_dev_attr_name.dev_attr);
553 goto exit_unregister;
555 /* CPU temperature attributes, if temperature reading is OK */
556 err = i8k_get_temp(0);
558 dev_dbg(i8k_hwmon_dev,
559 "Not creating temperature attributes (%d)\n", err);
561 err = device_create_file(i8k_hwmon_dev, &dev_attr_temp1_input);
563 goto exit_remove_files;
564 err = device_create_file(i8k_hwmon_dev,
565 &sensor_dev_attr_temp1_label.dev_attr);
567 goto exit_remove_files;
570 /* Left fan attributes, if left fan is present */
571 err = i8k_get_fan_status(I8K_FAN_LEFT);
573 dev_dbg(i8k_hwmon_dev,
574 "Not creating %s fan attributes (%d)\n", "left", err);
576 err = device_create_file(i8k_hwmon_dev,
577 &sensor_dev_attr_fan1_input.dev_attr);
579 goto exit_remove_files;
580 err = device_create_file(i8k_hwmon_dev,
581 &sensor_dev_attr_fan1_label.dev_attr);
583 goto exit_remove_files;
586 /* Right fan attributes, if right fan is present */
587 err = i8k_get_fan_status(I8K_FAN_RIGHT);
589 dev_dbg(i8k_hwmon_dev,
590 "Not creating %s fan attributes (%d)\n", "right", err);
592 err = device_create_file(i8k_hwmon_dev,
593 &sensor_dev_attr_fan2_input.dev_attr);
595 goto exit_remove_files;
596 err = device_create_file(i8k_hwmon_dev,
597 &sensor_dev_attr_fan2_label.dev_attr);
599 goto exit_remove_files;
605 i8k_hwmon_remove_files(i8k_hwmon_dev);
607 hwmon_device_unregister(i8k_hwmon_dev);
611 static void __exit i8k_exit_hwmon(void)
613 i8k_hwmon_remove_files(i8k_hwmon_dev);
614 hwmon_device_unregister(i8k_hwmon_dev);
617 static struct dmi_system_id i8k_dmi_table[] __initdata = {
619 .ident = "Dell Inspiron",
621 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
622 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
626 .ident = "Dell Latitude",
628 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
629 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
633 .ident = "Dell Inspiron 2",
635 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
636 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
640 .ident = "Dell Latitude 2",
642 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
643 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
646 { /* UK Inspiron 6400 */
647 .ident = "Dell Inspiron 3",
649 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
650 DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
654 .ident = "Dell Inspiron 3",
656 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
657 DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
661 .ident = "Dell Precision",
663 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
664 DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
668 .ident = "Dell Vostro",
670 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
671 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
675 .ident = "Dell XPS421",
677 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
678 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
685 * Probe for the presence of a supported laptop.
687 static int __init i8k_probe(void)
693 * Get DMI information
695 if (!dmi_check_system(i8k_dmi_table)) {
696 if (!ignore_dmi && !force)
699 pr_info("not running on a supported Dell system.\n");
700 pr_info("vendor=%s, model=%s, version=%s\n",
701 i8k_get_dmi_data(DMI_SYS_VENDOR),
702 i8k_get_dmi_data(DMI_PRODUCT_NAME),
703 i8k_get_dmi_data(DMI_BIOS_VERSION));
706 strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
707 sizeof(bios_version));
710 * Get SMM Dell signature
712 if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
713 i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
714 pr_err("unable to get SMM Dell signature\n");
720 * Get SMM BIOS version.
722 version = i8k_get_bios_version();
724 pr_warn("unable to get SMM BIOS version\n");
726 buff[0] = (version >> 16) & 0xff;
727 buff[1] = (version >> 8) & 0xff;
728 buff[2] = (version) & 0xff;
731 * If DMI BIOS version is unknown use SMM BIOS version.
733 if (!dmi_get_system_info(DMI_BIOS_VERSION))
734 strlcpy(bios_version, buff, sizeof(bios_version));
737 * Check if the two versions match.
739 if (strncmp(buff, bios_version, sizeof(bios_version)) != 0)
740 pr_warn("BIOS version mismatch: %s != %s\n",
747 static int __init i8k_init(void)
749 struct proc_dir_entry *proc_i8k;
752 /* Are we running on an supported laptop? */
756 /* Register the proc entry */
757 proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
761 err = i8k_init_hwmon();
763 goto exit_remove_proc;
765 pr_info("Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
771 remove_proc_entry("i8k", NULL);
775 static void __exit i8k_exit(void)
778 remove_proc_entry("i8k", NULL);
781 module_init(i8k_init);
782 module_exit(i8k_exit);