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;
69 static u32 i8k_hwmon_flags;
71 #define I8K_HWMON_HAVE_TEMP1 (1 << 0)
72 #define I8K_HWMON_HAVE_FAN1 (1 << 1)
73 #define I8K_HWMON_HAVE_FAN2 (1 << 2)
75 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
76 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
77 MODULE_LICENSE("GPL");
80 module_param(force, bool, 0);
81 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
83 static bool ignore_dmi;
84 module_param(ignore_dmi, bool, 0);
85 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
87 static bool restricted;
88 module_param(restricted, bool, 0);
89 MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
91 static bool power_status;
92 module_param(power_status, bool, 0600);
93 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
95 static int fan_mult = I8K_FAN_MULT;
96 module_param(fan_mult, int, 0);
97 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");
99 static int i8k_open_fs(struct inode *inode, struct file *file);
100 static long i8k_ioctl(struct file *, unsigned int, unsigned long);
102 static const struct file_operations i8k_fops = {
103 .owner = THIS_MODULE,
107 .release = single_release,
108 .unlocked_ioctl = i8k_ioctl,
113 unsigned int ebx __packed;
114 unsigned int ecx __packed;
115 unsigned int edx __packed;
116 unsigned int esi __packed;
117 unsigned int edi __packed;
120 static inline const char *i8k_get_dmi_data(int field)
122 const char *dmi_data = dmi_get_system_info(field);
124 return dmi_data && *dmi_data ? dmi_data : "?";
128 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
130 static int i8k_smm(struct smm_regs *regs)
135 #if defined(CONFIG_X86_64)
136 asm volatile("pushq %%rax\n\t"
137 "movl 0(%%rax),%%edx\n\t"
139 "movl 4(%%rax),%%ebx\n\t"
140 "movl 8(%%rax),%%ecx\n\t"
141 "movl 12(%%rax),%%edx\n\t"
142 "movl 16(%%rax),%%esi\n\t"
143 "movl 20(%%rax),%%edi\n\t"
147 "xchgq %%rax,(%%rsp)\n\t"
148 "movl %%ebx,4(%%rax)\n\t"
149 "movl %%ecx,8(%%rax)\n\t"
150 "movl %%edx,12(%%rax)\n\t"
151 "movl %%esi,16(%%rax)\n\t"
152 "movl %%edi,20(%%rax)\n\t"
154 "movl %%edx,0(%%rax)\n\t"
160 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
162 asm volatile("pushl %%eax\n\t"
163 "movl 0(%%eax),%%edx\n\t"
165 "movl 4(%%eax),%%ebx\n\t"
166 "movl 8(%%eax),%%ecx\n\t"
167 "movl 12(%%eax),%%edx\n\t"
168 "movl 16(%%eax),%%esi\n\t"
169 "movl 20(%%eax),%%edi\n\t"
173 "xchgl %%eax,(%%esp)\n\t"
174 "movl %%ebx,4(%%eax)\n\t"
175 "movl %%ecx,8(%%eax)\n\t"
176 "movl %%edx,12(%%eax)\n\t"
177 "movl %%esi,16(%%eax)\n\t"
178 "movl %%edi,20(%%eax)\n\t"
180 "movl %%edx,0(%%eax)\n\t"
186 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
188 if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
195 * Read the bios version. Return the version as an integer corresponding
196 * to the ascii value, for example "A17" is returned as 0x00413137.
198 static int i8k_get_bios_version(void)
200 struct smm_regs regs = { .eax = I8K_SMM_BIOS_VERSION, };
202 return i8k_smm(®s) ? : regs.eax;
206 * Read the Fn key status.
208 static int i8k_get_fn_status(void)
210 struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
217 switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
230 * Read the power status.
232 static int i8k_get_power_status(void)
234 struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
241 return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
245 * Read the fan status.
247 static int i8k_get_fan_status(int fan)
249 struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
251 regs.ebx = fan & 0xff;
252 return i8k_smm(®s) ? : regs.eax & 0xff;
256 * Read the fan speed in RPM.
258 static int i8k_get_fan_speed(int fan)
260 struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
262 regs.ebx = fan & 0xff;
263 return i8k_smm(®s) ? : (regs.eax & 0xffff) * fan_mult;
267 * Set the fan speed (off, low, high). Returns the new fan status.
269 static int i8k_set_fan(int fan, int speed)
271 struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
273 speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
274 regs.ebx = (fan & 0xff) | (speed << 8);
276 return i8k_smm(®s) ? : i8k_get_fan_status(fan);
280 * Read the cpu temperature.
282 static int i8k_get_temp(int sensor)
284 struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP, };
288 #ifdef I8K_TEMPERATURE_BUG
291 regs.ebx = sensor & 0xff;
296 temp = regs.eax & 0xff;
298 #ifdef I8K_TEMPERATURE_BUG
300 * Sometimes the temperature sensor returns 0x99, which is out of range.
301 * In this case we return (once) the previous cached value. For example:
302 # 1003655137 00000058 00005a4b
303 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
304 # 1003655139 00000054 00005c52
306 if (temp > I8K_MAX_TEMP) {
317 static int i8k_get_dell_signature(int req_fn)
319 struct smm_regs regs = { .eax = req_fn, };
326 return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
330 i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
334 unsigned char buff[16];
335 int __user *argp = (int __user *)arg;
341 case I8K_BIOS_VERSION:
342 val = i8k_get_bios_version();
347 strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
352 val = i8k_get_fn_status();
355 case I8K_POWER_STATUS:
356 val = i8k_get_power_status();
360 val = i8k_get_temp(0);
364 if (copy_from_user(&val, argp, sizeof(int)))
367 val = i8k_get_fan_speed(val);
371 if (copy_from_user(&val, argp, sizeof(int)))
374 val = i8k_get_fan_status(val);
378 if (restricted && !capable(CAP_SYS_ADMIN))
381 if (copy_from_user(&val, argp, sizeof(int)))
384 if (copy_from_user(&speed, argp + 1, sizeof(int)))
387 val = i8k_set_fan(val, speed);
398 case I8K_BIOS_VERSION:
399 if (copy_to_user(argp, &val, 4))
404 if (copy_to_user(argp, buff, 16))
409 if (copy_to_user(argp, &val, sizeof(int)))
418 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
422 mutex_lock(&i8k_mutex);
423 ret = i8k_ioctl_unlocked(fp, cmd, arg);
424 mutex_unlock(&i8k_mutex);
430 * Print the information for /proc/i8k.
432 static int i8k_proc_show(struct seq_file *seq, void *offset)
434 int fn_key, cpu_temp, ac_power;
435 int left_fan, right_fan, left_speed, right_speed;
437 cpu_temp = i8k_get_temp(0); /* 11100 µs */
438 left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 µs */
439 right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 µs */
440 left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 µs */
441 right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 µs */
442 fn_key = i8k_get_fn_status(); /* 750 µs */
444 ac_power = i8k_get_power_status(); /* 14700 µs */
451 * 1) Format version (this will change if format changes)
456 * 6) Right fan status
462 return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
465 i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
467 left_fan, right_fan, left_speed, right_speed,
471 static int i8k_open_fs(struct inode *inode, struct file *file)
473 return single_open(file, i8k_proc_show, NULL);
481 static ssize_t i8k_hwmon_show_temp(struct device *dev,
482 struct device_attribute *devattr,
487 cpu_temp = i8k_get_temp(0);
490 return sprintf(buf, "%d\n", cpu_temp * 1000);
493 static ssize_t i8k_hwmon_show_fan(struct device *dev,
494 struct device_attribute *devattr,
497 int index = to_sensor_dev_attr(devattr)->index;
500 fan_speed = i8k_get_fan_speed(index);
503 return sprintf(buf, "%d\n", fan_speed);
506 static ssize_t i8k_hwmon_show_label(struct device *dev,
507 struct device_attribute *devattr,
510 static const char *labels[3] = {
515 int index = to_sensor_dev_attr(devattr)->index;
517 return sprintf(buf, "%s\n", labels[index]);
520 static DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL);
521 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
523 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
525 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 0);
526 static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 1);
527 static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_label, NULL, 2);
529 static struct attribute *i8k_attrs[] = {
530 &dev_attr_temp1_input.attr, /* 0 */
531 &sensor_dev_attr_temp1_label.dev_attr.attr, /* 1 */
532 &sensor_dev_attr_fan1_input.dev_attr.attr, /* 2 */
533 &sensor_dev_attr_fan1_label.dev_attr.attr, /* 3 */
534 &sensor_dev_attr_fan2_input.dev_attr.attr, /* 4 */
535 &sensor_dev_attr_fan2_label.dev_attr.attr, /* 5 */
539 static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
542 if ((index == 0 || index == 1) &&
543 !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
545 if ((index == 2 || index == 3) &&
546 !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
548 if ((index == 4 || index == 5) &&
549 !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
555 static const struct attribute_group i8k_group = {
557 .is_visible = i8k_is_visible,
559 __ATTRIBUTE_GROUPS(i8k);
561 static int __init i8k_init_hwmon(void)
567 /* CPU temperature attributes, if temperature reading is OK */
568 err = i8k_get_temp(0);
570 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
572 /* Left fan attributes, if left fan is present */
573 err = i8k_get_fan_status(I8K_FAN_LEFT);
575 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
577 /* Right fan attributes, if right fan is present */
578 err = i8k_get_fan_status(I8K_FAN_RIGHT);
580 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
582 i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "i8k", NULL,
584 if (IS_ERR(i8k_hwmon_dev)) {
585 err = PTR_ERR(i8k_hwmon_dev);
586 i8k_hwmon_dev = NULL;
587 pr_err("hwmon registration failed (%d)\n", err);
593 static struct dmi_system_id i8k_dmi_table[] __initdata = {
595 .ident = "Dell Inspiron",
597 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
598 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
602 .ident = "Dell Latitude",
604 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
605 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
609 .ident = "Dell Inspiron 2",
611 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
612 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
616 .ident = "Dell Latitude 2",
618 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
619 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
622 { /* UK Inspiron 6400 */
623 .ident = "Dell Inspiron 3",
625 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
626 DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
630 .ident = "Dell Inspiron 3",
632 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
633 DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
637 .ident = "Dell Precision",
639 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
640 DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
644 .ident = "Dell Vostro",
646 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
647 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
651 .ident = "Dell XPS421",
653 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
654 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
661 * Probe for the presence of a supported laptop.
663 static int __init i8k_probe(void)
669 * Get DMI information
671 if (!dmi_check_system(i8k_dmi_table)) {
672 if (!ignore_dmi && !force)
675 pr_info("not running on a supported Dell system.\n");
676 pr_info("vendor=%s, model=%s, version=%s\n",
677 i8k_get_dmi_data(DMI_SYS_VENDOR),
678 i8k_get_dmi_data(DMI_PRODUCT_NAME),
679 i8k_get_dmi_data(DMI_BIOS_VERSION));
682 strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
683 sizeof(bios_version));
686 * Get SMM Dell signature
688 if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
689 i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
690 pr_err("unable to get SMM Dell signature\n");
696 * Get SMM BIOS version.
698 version = i8k_get_bios_version();
700 pr_warn("unable to get SMM BIOS version\n");
702 buff[0] = (version >> 16) & 0xff;
703 buff[1] = (version >> 8) & 0xff;
704 buff[2] = (version) & 0xff;
707 * If DMI BIOS version is unknown use SMM BIOS version.
709 if (!dmi_get_system_info(DMI_BIOS_VERSION))
710 strlcpy(bios_version, buff, sizeof(bios_version));
713 * Check if the two versions match.
715 if (strncmp(buff, bios_version, sizeof(bios_version)) != 0)
716 pr_warn("BIOS version mismatch: %s != %s\n",
723 static int __init i8k_init(void)
725 struct proc_dir_entry *proc_i8k;
728 /* Are we running on an supported laptop? */
732 /* Register the proc entry */
733 proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
737 err = i8k_init_hwmon();
739 goto exit_remove_proc;
741 pr_info("Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
747 remove_proc_entry("i8k", NULL);
751 static void __exit i8k_exit(void)
753 hwmon_device_unregister(i8k_hwmon_dev);
754 remove_proc_entry("i8k", NULL);
757 module_init(i8k_init);
758 module_exit(i8k_exit);