2 * i8k.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
4 * Copyright (C) 2001 Massimo Dal Zotto <dz@debian.org>
7 * Copyright (C) 2011 Jean Delvare <khali@linux-fr.org>
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2, or (at your option) any
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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 <linux/uaccess.h>
34 #include <linux/sched.h>
36 #include <linux/i8k.h>
38 #define I8K_SMM_FN_STATUS 0x0025
39 #define I8K_SMM_POWER_STATUS 0x0069
40 #define I8K_SMM_SET_FAN 0x01a3
41 #define I8K_SMM_GET_FAN 0x00a3
42 #define I8K_SMM_GET_SPEED 0x02a3
43 #define I8K_SMM_GET_TEMP 0x10a3
44 #define I8K_SMM_GET_DELL_SIG1 0xfea3
45 #define I8K_SMM_GET_DELL_SIG2 0xffa3
46 #define I8K_SMM_BIOS_VERSION 0x00a6
48 #define I8K_FAN_MULT 30
49 #define I8K_MAX_TEMP 127
51 #define I8K_FN_NONE 0x00
52 #define I8K_FN_UP 0x01
53 #define I8K_FN_DOWN 0x02
54 #define I8K_FN_MUTE 0x04
55 #define I8K_FN_MASK 0x07
56 #define I8K_FN_SHIFT 8
58 #define I8K_POWER_AC 0x05
59 #define I8K_POWER_BATTERY 0x01
61 #define I8K_TEMPERATURE_BUG 1
63 static DEFINE_MUTEX(i8k_mutex);
64 static char bios_version[4];
65 static struct device *i8k_hwmon_dev;
66 static u32 i8k_hwmon_flags;
68 #define I8K_HWMON_HAVE_TEMP1 (1 << 0)
69 #define I8K_HWMON_HAVE_TEMP2 (1 << 1)
70 #define I8K_HWMON_HAVE_TEMP3 (1 << 2)
71 #define I8K_HWMON_HAVE_TEMP4 (1 << 3)
72 #define I8K_HWMON_HAVE_FAN1 (1 << 4)
73 #define I8K_HWMON_HAVE_FAN2 (1 << 5)
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)
134 cpumask_var_t old_mask;
136 /* SMM requires CPU 0 */
137 if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
139 cpumask_copy(old_mask, ¤t->cpus_allowed);
140 set_cpus_allowed_ptr(current, cpumask_of(0));
141 if (smp_processor_id() != 0) {
146 #if defined(CONFIG_X86_64)
147 asm volatile("pushq %%rax\n\t"
148 "movl 0(%%rax),%%edx\n\t"
150 "movl 4(%%rax),%%ebx\n\t"
151 "movl 8(%%rax),%%ecx\n\t"
152 "movl 12(%%rax),%%edx\n\t"
153 "movl 16(%%rax),%%esi\n\t"
154 "movl 20(%%rax),%%edi\n\t"
158 "xchgq %%rax,(%%rsp)\n\t"
159 "movl %%ebx,4(%%rax)\n\t"
160 "movl %%ecx,8(%%rax)\n\t"
161 "movl %%edx,12(%%rax)\n\t"
162 "movl %%esi,16(%%rax)\n\t"
163 "movl %%edi,20(%%rax)\n\t"
165 "movl %%edx,0(%%rax)\n\t"
171 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
173 asm volatile("pushl %%eax\n\t"
174 "movl 0(%%eax),%%edx\n\t"
176 "movl 4(%%eax),%%ebx\n\t"
177 "movl 8(%%eax),%%ecx\n\t"
178 "movl 12(%%eax),%%edx\n\t"
179 "movl 16(%%eax),%%esi\n\t"
180 "movl 20(%%eax),%%edi\n\t"
184 "xchgl %%eax,(%%esp)\n\t"
185 "movl %%ebx,4(%%eax)\n\t"
186 "movl %%ecx,8(%%eax)\n\t"
187 "movl %%edx,12(%%eax)\n\t"
188 "movl %%esi,16(%%eax)\n\t"
189 "movl %%edi,20(%%eax)\n\t"
191 "movl %%edx,0(%%eax)\n\t"
197 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
199 if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
203 set_cpus_allowed_ptr(current, old_mask);
204 free_cpumask_var(old_mask);
209 * Read the bios version. Return the version as an integer corresponding
210 * to the ascii value, for example "A17" is returned as 0x00413137.
212 static int i8k_get_bios_version(void)
214 struct smm_regs regs = { .eax = I8K_SMM_BIOS_VERSION, };
216 return i8k_smm(®s) ? : regs.eax;
220 * Read the Fn key status.
222 static int i8k_get_fn_status(void)
224 struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
231 switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
244 * Read the power status.
246 static int i8k_get_power_status(void)
248 struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
255 return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
259 * Read the fan status.
261 static int i8k_get_fan_status(int fan)
263 struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
265 regs.ebx = fan & 0xff;
266 return i8k_smm(®s) ? : regs.eax & 0xff;
270 * Read the fan speed in RPM.
272 static int i8k_get_fan_speed(int fan)
274 struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
276 regs.ebx = fan & 0xff;
277 return i8k_smm(®s) ? : (regs.eax & 0xffff) * fan_mult;
281 * Set the fan speed (off, low, high). Returns the new fan status.
283 static int i8k_set_fan(int fan, int speed)
285 struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
287 speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
288 regs.ebx = (fan & 0xff) | (speed << 8);
290 return i8k_smm(®s) ? : i8k_get_fan_status(fan);
294 * Read the cpu temperature.
296 static int i8k_get_temp(int sensor)
298 struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP, };
302 #ifdef I8K_TEMPERATURE_BUG
305 regs.ebx = sensor & 0xff;
310 temp = regs.eax & 0xff;
312 #ifdef I8K_TEMPERATURE_BUG
314 * Sometimes the temperature sensor returns 0x99, which is out of range.
315 * In this case we return (once) the previous cached value. For example:
316 # 1003655137 00000058 00005a4b
317 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
318 # 1003655139 00000054 00005c52
320 if (temp > I8K_MAX_TEMP) {
322 prev[sensor] = I8K_MAX_TEMP;
331 static int i8k_get_dell_signature(int req_fn)
333 struct smm_regs regs = { .eax = req_fn, };
340 return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
344 i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
348 unsigned char buff[16];
349 int __user *argp = (int __user *)arg;
355 case I8K_BIOS_VERSION:
356 val = i8k_get_bios_version();
361 strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
366 val = i8k_get_fn_status();
369 case I8K_POWER_STATUS:
370 val = i8k_get_power_status();
374 val = i8k_get_temp(0);
378 if (copy_from_user(&val, argp, sizeof(int)))
381 val = i8k_get_fan_speed(val);
385 if (copy_from_user(&val, argp, sizeof(int)))
388 val = i8k_get_fan_status(val);
392 if (restricted && !capable(CAP_SYS_ADMIN))
395 if (copy_from_user(&val, argp, sizeof(int)))
398 if (copy_from_user(&speed, argp + 1, sizeof(int)))
401 val = i8k_set_fan(val, speed);
412 case I8K_BIOS_VERSION:
413 if (copy_to_user(argp, &val, 4))
418 if (copy_to_user(argp, buff, 16))
423 if (copy_to_user(argp, &val, sizeof(int)))
432 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
436 mutex_lock(&i8k_mutex);
437 ret = i8k_ioctl_unlocked(fp, cmd, arg);
438 mutex_unlock(&i8k_mutex);
444 * Print the information for /proc/i8k.
446 static int i8k_proc_show(struct seq_file *seq, void *offset)
448 int fn_key, cpu_temp, ac_power;
449 int left_fan, right_fan, left_speed, right_speed;
451 cpu_temp = i8k_get_temp(0); /* 11100 µs */
452 left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 µs */
453 right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 µs */
454 left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 µs */
455 right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 µs */
456 fn_key = i8k_get_fn_status(); /* 750 µs */
458 ac_power = i8k_get_power_status(); /* 14700 µs */
465 * 1) Format version (this will change if format changes)
470 * 6) Right fan status
476 return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
479 i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
481 left_fan, right_fan, left_speed, right_speed,
485 static int i8k_open_fs(struct inode *inode, struct file *file)
487 return single_open(file, i8k_proc_show, NULL);
495 static ssize_t i8k_hwmon_show_temp(struct device *dev,
496 struct device_attribute *devattr,
499 int index = to_sensor_dev_attr(devattr)->index;
502 temp = i8k_get_temp(index);
505 return sprintf(buf, "%d\n", temp * 1000);
508 static ssize_t i8k_hwmon_show_fan(struct device *dev,
509 struct device_attribute *devattr,
512 int index = to_sensor_dev_attr(devattr)->index;
515 fan_speed = i8k_get_fan_speed(index);
518 return sprintf(buf, "%d\n", fan_speed);
521 static ssize_t i8k_hwmon_show_label(struct device *dev,
522 struct device_attribute *devattr,
525 static const char *labels[3] = {
530 int index = to_sensor_dev_attr(devattr)->index;
532 return sprintf(buf, "%s\n", labels[index]);
535 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 0);
536 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 1);
537 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 2);
538 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 3);
539 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
541 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
543 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 0);
544 static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 1);
545 static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_label, NULL, 2);
547 static struct attribute *i8k_attrs[] = {
548 &sensor_dev_attr_temp1_input.dev_attr.attr, /* 0 */
549 &sensor_dev_attr_temp1_label.dev_attr.attr, /* 1 */
550 &sensor_dev_attr_temp2_input.dev_attr.attr, /* 2 */
551 &sensor_dev_attr_temp3_input.dev_attr.attr, /* 3 */
552 &sensor_dev_attr_temp4_input.dev_attr.attr, /* 4 */
553 &sensor_dev_attr_fan1_input.dev_attr.attr, /* 5 */
554 &sensor_dev_attr_fan1_label.dev_attr.attr, /* 6 */
555 &sensor_dev_attr_fan2_input.dev_attr.attr, /* 7 */
556 &sensor_dev_attr_fan2_label.dev_attr.attr, /* 8 */
560 static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
563 if ((index == 0 || index == 1) &&
564 !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
566 if (index == 2 && !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP2))
568 if (index == 3 && !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP3))
570 if (index == 4 && !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP4))
572 if ((index == 5 || index == 6) &&
573 !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
575 if ((index == 7 || index == 8) &&
576 !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
582 static const struct attribute_group i8k_group = {
584 .is_visible = i8k_is_visible,
586 __ATTRIBUTE_GROUPS(i8k);
588 static int __init i8k_init_hwmon(void)
594 /* CPU temperature attributes, if temperature reading is OK */
595 err = i8k_get_temp(0);
597 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
598 /* check for additional temperature sensors */
599 err = i8k_get_temp(1);
601 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2;
602 err = i8k_get_temp(2);
604 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3;
605 err = i8k_get_temp(3);
607 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
609 /* Left fan attributes, if left fan is present */
610 err = i8k_get_fan_status(I8K_FAN_LEFT);
612 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
614 /* Right fan attributes, if right fan is present */
615 err = i8k_get_fan_status(I8K_FAN_RIGHT);
617 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
619 i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "i8k", NULL,
621 if (IS_ERR(i8k_hwmon_dev)) {
622 err = PTR_ERR(i8k_hwmon_dev);
623 i8k_hwmon_dev = NULL;
624 pr_err("hwmon registration failed (%d)\n", err);
630 static struct dmi_system_id i8k_dmi_table[] __initdata = {
632 .ident = "Dell Inspiron",
634 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
635 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
639 .ident = "Dell Latitude",
641 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
642 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
646 .ident = "Dell Inspiron 2",
648 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
649 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
653 .ident = "Dell Latitude 2",
655 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
656 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
659 { /* UK Inspiron 6400 */
660 .ident = "Dell Inspiron 3",
662 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
663 DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
667 .ident = "Dell Inspiron 3",
669 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
670 DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
674 .ident = "Dell Precision",
676 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
677 DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
681 .ident = "Dell Vostro",
683 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
684 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
688 .ident = "Dell XPS421",
690 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
691 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
698 * Probe for the presence of a supported laptop.
700 static int __init i8k_probe(void)
706 * Get DMI information
708 if (!dmi_check_system(i8k_dmi_table)) {
709 if (!ignore_dmi && !force)
712 pr_info("not running on a supported Dell system.\n");
713 pr_info("vendor=%s, model=%s, version=%s\n",
714 i8k_get_dmi_data(DMI_SYS_VENDOR),
715 i8k_get_dmi_data(DMI_PRODUCT_NAME),
716 i8k_get_dmi_data(DMI_BIOS_VERSION));
719 strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
720 sizeof(bios_version));
723 * Get SMM Dell signature
725 if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
726 i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
727 pr_err("unable to get SMM Dell signature\n");
733 * Get SMM BIOS version.
735 version = i8k_get_bios_version();
737 pr_warn("unable to get SMM BIOS version\n");
739 buff[0] = (version >> 16) & 0xff;
740 buff[1] = (version >> 8) & 0xff;
741 buff[2] = (version) & 0xff;
744 * If DMI BIOS version is unknown use SMM BIOS version.
746 if (!dmi_get_system_info(DMI_BIOS_VERSION))
747 strlcpy(bios_version, buff, sizeof(bios_version));
750 * Check if the two versions match.
752 if (strncmp(buff, bios_version, sizeof(bios_version)) != 0)
753 pr_warn("BIOS version mismatch: %s != %s\n",
760 static int __init i8k_init(void)
762 struct proc_dir_entry *proc_i8k;
765 /* Are we running on an supported laptop? */
769 /* Register the proc entry */
770 proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
774 err = i8k_init_hwmon();
776 goto exit_remove_proc;
781 remove_proc_entry("i8k", NULL);
785 static void __exit i8k_exit(void)
787 hwmon_device_unregister(i8k_hwmon_dev);
788 remove_proc_entry("i8k", NULL);
791 module_init(i8k_init);
792 module_exit(i8k_exit);