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>
8 * Copyright (C) 2013 Guenter Roeck <linux@roeck-us.net>
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2, or (at your option) any
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23 #include <linux/module.h>
24 #include <linux/types.h>
25 #include <linux/init.h>
26 #include <linux/proc_fs.h>
27 #include <linux/seq_file.h>
28 #include <linux/dmi.h>
29 #include <linux/capability.h>
30 #include <linux/mutex.h>
31 #include <linux/hwmon.h>
32 #include <linux/hwmon-sysfs.h>
33 #include <linux/uaccess.h>
35 #include <linux/sched.h>
37 #include <linux/i8k.h>
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;
67 static u32 i8k_hwmon_flags;
68 static int i8k_fan_mult;
70 #define I8K_HWMON_HAVE_TEMP1 (1 << 0)
71 #define I8K_HWMON_HAVE_TEMP2 (1 << 1)
72 #define I8K_HWMON_HAVE_TEMP3 (1 << 2)
73 #define I8K_HWMON_HAVE_TEMP4 (1 << 3)
74 #define I8K_HWMON_HAVE_FAN1 (1 << 4)
75 #define I8K_HWMON_HAVE_FAN2 (1 << 5)
77 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
78 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
79 MODULE_LICENSE("GPL");
82 module_param(force, bool, 0);
83 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
85 static bool ignore_dmi;
86 module_param(ignore_dmi, bool, 0);
87 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
89 static bool restricted;
90 module_param(restricted, bool, 0);
91 MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
93 static bool power_status;
94 module_param(power_status, bool, 0600);
95 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
97 static int fan_mult = I8K_FAN_MULT;
98 module_param(fan_mult, int, 0);
99 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");
101 static int i8k_open_fs(struct inode *inode, struct file *file);
102 static long i8k_ioctl(struct file *, unsigned int, unsigned long);
104 static const struct file_operations i8k_fops = {
105 .owner = THIS_MODULE,
109 .release = single_release,
110 .unlocked_ioctl = i8k_ioctl,
115 unsigned int ebx __packed;
116 unsigned int ecx __packed;
117 unsigned int edx __packed;
118 unsigned int esi __packed;
119 unsigned int edi __packed;
122 static inline const char *i8k_get_dmi_data(int field)
124 const char *dmi_data = dmi_get_system_info(field);
126 return dmi_data && *dmi_data ? dmi_data : "?";
130 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
132 static int i8k_smm(struct smm_regs *regs)
136 cpumask_var_t old_mask;
138 /* SMM requires CPU 0 */
139 if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
141 cpumask_copy(old_mask, ¤t->cpus_allowed);
142 set_cpus_allowed_ptr(current, cpumask_of(0));
143 if (smp_processor_id() != 0) {
148 #if defined(CONFIG_X86_64)
149 asm volatile("pushq %%rax\n\t"
150 "movl 0(%%rax),%%edx\n\t"
152 "movl 4(%%rax),%%ebx\n\t"
153 "movl 8(%%rax),%%ecx\n\t"
154 "movl 12(%%rax),%%edx\n\t"
155 "movl 16(%%rax),%%esi\n\t"
156 "movl 20(%%rax),%%edi\n\t"
160 "xchgq %%rax,(%%rsp)\n\t"
161 "movl %%ebx,4(%%rax)\n\t"
162 "movl %%ecx,8(%%rax)\n\t"
163 "movl %%edx,12(%%rax)\n\t"
164 "movl %%esi,16(%%rax)\n\t"
165 "movl %%edi,20(%%rax)\n\t"
167 "movl %%edx,0(%%rax)\n\t"
173 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
175 asm volatile("pushl %%eax\n\t"
176 "movl 0(%%eax),%%edx\n\t"
178 "movl 4(%%eax),%%ebx\n\t"
179 "movl 8(%%eax),%%ecx\n\t"
180 "movl 12(%%eax),%%edx\n\t"
181 "movl 16(%%eax),%%esi\n\t"
182 "movl 20(%%eax),%%edi\n\t"
186 "xchgl %%eax,(%%esp)\n\t"
187 "movl %%ebx,4(%%eax)\n\t"
188 "movl %%ecx,8(%%eax)\n\t"
189 "movl %%edx,12(%%eax)\n\t"
190 "movl %%esi,16(%%eax)\n\t"
191 "movl %%edi,20(%%eax)\n\t"
193 "movl %%edx,0(%%eax)\n\t"
199 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
201 if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
205 set_cpus_allowed_ptr(current, old_mask);
206 free_cpumask_var(old_mask);
211 * Read the bios version. Return the version as an integer corresponding
212 * to the ascii value, for example "A17" is returned as 0x00413137.
214 static int i8k_get_bios_version(void)
216 struct smm_regs regs = { .eax = I8K_SMM_BIOS_VERSION, };
218 return i8k_smm(®s) ? : regs.eax;
222 * Read the Fn key status.
224 static int i8k_get_fn_status(void)
226 struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
233 switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
246 * Read the power status.
248 static int i8k_get_power_status(void)
250 struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
257 return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
261 * Read the fan status.
263 static int i8k_get_fan_status(int fan)
265 struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
267 regs.ebx = fan & 0xff;
268 return i8k_smm(®s) ? : regs.eax & 0xff;
272 * Read the fan speed in RPM.
274 static int i8k_get_fan_speed(int fan)
276 struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
278 regs.ebx = fan & 0xff;
279 return i8k_smm(®s) ? : (regs.eax & 0xffff) * i8k_fan_mult;
283 * Set the fan speed (off, low, high). Returns the new fan status.
285 static int i8k_set_fan(int fan, int speed)
287 struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
289 speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
290 regs.ebx = (fan & 0xff) | (speed << 8);
292 return i8k_smm(®s) ? : i8k_get_fan_status(fan);
296 * Read the cpu temperature.
298 static int i8k_get_temp(int sensor)
300 struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP, };
304 #ifdef I8K_TEMPERATURE_BUG
307 regs.ebx = sensor & 0xff;
312 temp = regs.eax & 0xff;
314 #ifdef I8K_TEMPERATURE_BUG
316 * Sometimes the temperature sensor returns 0x99, which is out of range.
317 * In this case we return (once) the previous cached value. For example:
318 # 1003655137 00000058 00005a4b
319 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
320 # 1003655139 00000054 00005c52
322 if (temp > I8K_MAX_TEMP) {
324 prev[sensor] = I8K_MAX_TEMP;
333 static int i8k_get_dell_signature(int req_fn)
335 struct smm_regs regs = { .eax = req_fn, };
342 return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
346 i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
350 unsigned char buff[16];
351 int __user *argp = (int __user *)arg;
357 case I8K_BIOS_VERSION:
358 val = i8k_get_bios_version();
363 strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
368 val = i8k_get_fn_status();
371 case I8K_POWER_STATUS:
372 val = i8k_get_power_status();
376 val = i8k_get_temp(0);
380 if (copy_from_user(&val, argp, sizeof(int)))
383 val = i8k_get_fan_speed(val);
387 if (copy_from_user(&val, argp, sizeof(int)))
390 val = i8k_get_fan_status(val);
394 if (restricted && !capable(CAP_SYS_ADMIN))
397 if (copy_from_user(&val, argp, sizeof(int)))
400 if (copy_from_user(&speed, argp + 1, sizeof(int)))
403 val = i8k_set_fan(val, speed);
414 case I8K_BIOS_VERSION:
415 if (copy_to_user(argp, &val, 4))
420 if (copy_to_user(argp, buff, 16))
425 if (copy_to_user(argp, &val, sizeof(int)))
434 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
438 mutex_lock(&i8k_mutex);
439 ret = i8k_ioctl_unlocked(fp, cmd, arg);
440 mutex_unlock(&i8k_mutex);
446 * Print the information for /proc/i8k.
448 static int i8k_proc_show(struct seq_file *seq, void *offset)
450 int fn_key, cpu_temp, ac_power;
451 int left_fan, right_fan, left_speed, right_speed;
453 cpu_temp = i8k_get_temp(0); /* 11100 µs */
454 left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 µs */
455 right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 µs */
456 left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 µs */
457 right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 µs */
458 fn_key = i8k_get_fn_status(); /* 750 µs */
460 ac_power = i8k_get_power_status(); /* 14700 µs */
467 * 1) Format version (this will change if format changes)
472 * 6) Right fan status
478 return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
481 i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
483 left_fan, right_fan, left_speed, right_speed,
487 static int i8k_open_fs(struct inode *inode, struct file *file)
489 return single_open(file, i8k_proc_show, NULL);
497 static ssize_t i8k_hwmon_show_temp(struct device *dev,
498 struct device_attribute *devattr,
501 int index = to_sensor_dev_attr(devattr)->index;
504 temp = i8k_get_temp(index);
507 return sprintf(buf, "%d\n", temp * 1000);
510 static ssize_t i8k_hwmon_show_fan(struct device *dev,
511 struct device_attribute *devattr,
514 int index = to_sensor_dev_attr(devattr)->index;
517 fan_speed = i8k_get_fan_speed(index);
520 return sprintf(buf, "%d\n", fan_speed);
523 static ssize_t i8k_hwmon_show_label(struct device *dev,
524 struct device_attribute *devattr,
527 static const char *labels[3] = {
532 int index = to_sensor_dev_attr(devattr)->index;
534 return sprintf(buf, "%s\n", labels[index]);
537 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 0);
538 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 1);
539 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 2);
540 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 3);
541 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
543 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
545 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 0);
546 static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 1);
547 static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_label, NULL, 2);
549 static struct attribute *i8k_attrs[] = {
550 &sensor_dev_attr_temp1_input.dev_attr.attr, /* 0 */
551 &sensor_dev_attr_temp1_label.dev_attr.attr, /* 1 */
552 &sensor_dev_attr_temp2_input.dev_attr.attr, /* 2 */
553 &sensor_dev_attr_temp3_input.dev_attr.attr, /* 3 */
554 &sensor_dev_attr_temp4_input.dev_attr.attr, /* 4 */
555 &sensor_dev_attr_fan1_input.dev_attr.attr, /* 5 */
556 &sensor_dev_attr_fan1_label.dev_attr.attr, /* 6 */
557 &sensor_dev_attr_fan2_input.dev_attr.attr, /* 7 */
558 &sensor_dev_attr_fan2_label.dev_attr.attr, /* 8 */
562 static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
565 if ((index == 0 || index == 1) &&
566 !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
568 if (index == 2 && !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP2))
570 if (index == 3 && !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP3))
572 if (index == 4 && !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP4))
574 if ((index == 5 || index == 6) &&
575 !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
577 if ((index == 7 || index == 8) &&
578 !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
584 static const struct attribute_group i8k_group = {
586 .is_visible = i8k_is_visible,
588 __ATTRIBUTE_GROUPS(i8k);
590 static int __init i8k_init_hwmon(void)
596 /* CPU temperature attributes, if temperature reading is OK */
597 err = i8k_get_temp(0);
599 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
600 /* check for additional temperature sensors */
601 err = i8k_get_temp(1);
603 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2;
604 err = i8k_get_temp(2);
606 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3;
607 err = i8k_get_temp(3);
609 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
611 /* Left fan attributes, if left fan is present */
612 err = i8k_get_fan_status(I8K_FAN_LEFT);
614 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
616 /* Right fan attributes, if right fan is present */
617 err = i8k_get_fan_status(I8K_FAN_RIGHT);
619 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
621 i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "i8k", NULL,
623 if (IS_ERR(i8k_hwmon_dev)) {
624 err = PTR_ERR(i8k_hwmon_dev);
625 i8k_hwmon_dev = NULL;
626 pr_err("hwmon registration failed (%d)\n", err);
632 static struct dmi_system_id i8k_dmi_table[] __initdata = {
634 .ident = "Dell Inspiron",
636 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
637 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
641 .ident = "Dell Latitude",
643 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
644 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
648 .ident = "Dell Inspiron 2",
650 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
651 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
655 .ident = "Dell Latitude 2",
657 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
658 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
661 { /* UK Inspiron 6400 */
662 .ident = "Dell Inspiron 3",
664 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
665 DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
669 .ident = "Dell Inspiron 3",
671 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
672 DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
676 .ident = "Dell Precision",
678 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
679 DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
683 .ident = "Dell Vostro",
685 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
686 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
690 .ident = "Dell XPS421",
692 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
693 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
697 .ident = "Dell Studio",
699 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
700 DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
702 .driver_data = (void *)1, /* fan multiplier override */
705 .ident = "Dell XPS M140",
707 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
708 DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
710 .driver_data = (void *)1, /* fan multiplier override */
716 * Probe for the presence of a supported laptop.
718 static int __init i8k_probe(void)
722 const struct dmi_system_id *id;
725 * Get DMI information
727 if (!dmi_check_system(i8k_dmi_table)) {
728 if (!ignore_dmi && !force)
731 pr_info("not running on a supported Dell system.\n");
732 pr_info("vendor=%s, model=%s, version=%s\n",
733 i8k_get_dmi_data(DMI_SYS_VENDOR),
734 i8k_get_dmi_data(DMI_PRODUCT_NAME),
735 i8k_get_dmi_data(DMI_BIOS_VERSION));
738 strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
739 sizeof(bios_version));
742 * Get SMM Dell signature
744 if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
745 i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
746 pr_err("unable to get SMM Dell signature\n");
752 * Get SMM BIOS version.
754 version = i8k_get_bios_version();
756 pr_warn("unable to get SMM BIOS version\n");
758 buff[0] = (version >> 16) & 0xff;
759 buff[1] = (version >> 8) & 0xff;
760 buff[2] = (version) & 0xff;
763 * If DMI BIOS version is unknown use SMM BIOS version.
765 if (!dmi_get_system_info(DMI_BIOS_VERSION))
766 strlcpy(bios_version, buff, sizeof(bios_version));
769 * Check if the two versions match.
771 if (strncmp(buff, bios_version, sizeof(bios_version)) != 0)
772 pr_warn("BIOS version mismatch: %s != %s\n",
776 i8k_fan_mult = fan_mult;
777 id = dmi_first_match(i8k_dmi_table);
778 if (id && fan_mult == I8K_FAN_MULT && id->driver_data)
779 i8k_fan_mult = (unsigned long)id->driver_data;
784 static int __init i8k_init(void)
786 struct proc_dir_entry *proc_i8k;
789 /* Are we running on an supported laptop? */
793 /* Register the proc entry */
794 proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
798 err = i8k_init_hwmon();
800 goto exit_remove_proc;
805 remove_proc_entry("i8k", NULL);
809 static void __exit i8k_exit(void)
811 hwmon_device_unregister(i8k_hwmon_dev);
812 remove_proc_entry("i8k", NULL);
815 module_init(i8k_init);
816 module_exit(i8k_exit);