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path: root/drivers/char/i8k.c
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-rw-r--r--drivers/char/i8k.c788
1 files changed, 788 insertions, 0 deletions
diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c
new file mode 100644
index 000000000000..a81197640283
--- /dev/null
+++ b/drivers/char/i8k.c
@@ -0,0 +1,788 @@
+/*
+ * i8k.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
+ * See http://www.debian.org/~dz/i8k/ for more information
+ * and for latest version of this driver.
+ *
+ * Copyright (C) 2001 Massimo Dal Zotto <dz@debian.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/apm_bios.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+#include <linux/i8k.h>
+
+#define I8K_VERSION "1.13 14/05/2002"
+
+#define I8K_SMM_FN_STATUS 0x0025
+#define I8K_SMM_POWER_STATUS 0x0069
+#define I8K_SMM_SET_FAN 0x01a3
+#define I8K_SMM_GET_FAN 0x00a3
+#define I8K_SMM_GET_SPEED 0x02a3
+#define I8K_SMM_GET_TEMP 0x10a3
+#define I8K_SMM_GET_DELL_SIG 0xffa3
+#define I8K_SMM_BIOS_VERSION 0x00a6
+
+#define I8K_FAN_MULT 30
+#define I8K_MAX_TEMP 127
+
+#define I8K_FN_NONE 0x00
+#define I8K_FN_UP 0x01
+#define I8K_FN_DOWN 0x02
+#define I8K_FN_MUTE 0x04
+#define I8K_FN_MASK 0x07
+#define I8K_FN_SHIFT 8
+
+#define I8K_POWER_AC 0x05
+#define I8K_POWER_BATTERY 0x01
+
+#define I8K_TEMPERATURE_BUG 1
+
+#define DELL_SIGNATURE "Dell Computer"
+
+static char *supported_models[] = {
+ "Inspiron",
+ "Latitude",
+ NULL
+};
+
+static char system_vendor[48] = "?";
+static char product_name [48] = "?";
+static char bios_version [4] = "?";
+static char serial_number[16] = "?";
+
+MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
+MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
+MODULE_LICENSE("GPL");
+
+static int force;
+module_param(force, bool, 0);
+MODULE_PARM_DESC(force, "Force loading without checking for supported models");
+
+static int restricted;
+module_param(restricted, bool, 0);
+MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
+
+static int power_status;
+module_param(power_status, bool, 0600);
+MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
+
+static ssize_t i8k_read(struct file *, char __user *, size_t, loff_t *);
+static int i8k_ioctl(struct inode *, struct file *, unsigned int,
+ unsigned long);
+
+static struct file_operations i8k_fops = {
+ .read = i8k_read,
+ .ioctl = i8k_ioctl,
+};
+
+typedef struct {
+ unsigned int eax;
+ unsigned int ebx __attribute__ ((packed));
+ unsigned int ecx __attribute__ ((packed));
+ unsigned int edx __attribute__ ((packed));
+ unsigned int esi __attribute__ ((packed));
+ unsigned int edi __attribute__ ((packed));
+} SMMRegisters;
+
+typedef struct {
+ u8 type;
+ u8 length;
+ u16 handle;
+} DMIHeader;
+
+/*
+ * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
+ */
+static int i8k_smm(SMMRegisters *regs)
+{
+ int rc;
+ int eax = regs->eax;
+
+ asm("pushl %%eax\n\t" \
+ "movl 0(%%eax),%%edx\n\t" \
+ "push %%edx\n\t" \
+ "movl 4(%%eax),%%ebx\n\t" \
+ "movl 8(%%eax),%%ecx\n\t" \
+ "movl 12(%%eax),%%edx\n\t" \
+ "movl 16(%%eax),%%esi\n\t" \
+ "movl 20(%%eax),%%edi\n\t" \
+ "popl %%eax\n\t" \
+ "out %%al,$0xb2\n\t" \
+ "out %%al,$0x84\n\t" \
+ "xchgl %%eax,(%%esp)\n\t"
+ "movl %%ebx,4(%%eax)\n\t" \
+ "movl %%ecx,8(%%eax)\n\t" \
+ "movl %%edx,12(%%eax)\n\t" \
+ "movl %%esi,16(%%eax)\n\t" \
+ "movl %%edi,20(%%eax)\n\t" \
+ "popl %%edx\n\t" \
+ "movl %%edx,0(%%eax)\n\t" \
+ "lahf\n\t" \
+ "shrl $8,%%eax\n\t" \
+ "andl $1,%%eax\n" \
+ : "=a" (rc)
+ : "a" (regs)
+ : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
+
+ if ((rc != 0) || ((regs->eax & 0xffff) == 0xffff) || (regs->eax == eax)) {
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/*
+ * Read the bios version. Return the version as an integer corresponding
+ * to the ascii value, for example "A17" is returned as 0x00413137.
+ */
+static int i8k_get_bios_version(void)
+{
+ SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
+ int rc;
+
+ regs.eax = I8K_SMM_BIOS_VERSION;
+ if ((rc=i8k_smm(&regs)) < 0) {
+ return rc;
+ }
+
+ return regs.eax;
+}
+
+/*
+ * Read the machine id.
+ */
+static int i8k_get_serial_number(unsigned char *buff)
+{
+ strlcpy(buff, serial_number, sizeof(serial_number));
+ return 0;
+}
+
+/*
+ * Read the Fn key status.
+ */
+static int i8k_get_fn_status(void)
+{
+ SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
+ int rc;
+
+ regs.eax = I8K_SMM_FN_STATUS;
+ if ((rc=i8k_smm(&regs)) < 0) {
+ return rc;
+ }
+
+ switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
+ case I8K_FN_UP:
+ return I8K_VOL_UP;
+ case I8K_FN_DOWN:
+ return I8K_VOL_DOWN;
+ case I8K_FN_MUTE:
+ return I8K_VOL_MUTE;
+ default:
+ return 0;
+ }
+}
+
+/*
+ * Read the power status.
+ */
+static int i8k_get_power_status(void)
+{
+ SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
+ int rc;
+
+ regs.eax = I8K_SMM_POWER_STATUS;
+ if ((rc=i8k_smm(&regs)) < 0) {
+ return rc;
+ }
+
+ switch (regs.eax & 0xff) {
+ case I8K_POWER_AC:
+ return I8K_AC;
+ default:
+ return I8K_BATTERY;
+ }
+}
+
+/*
+ * Read the fan status.
+ */
+static int i8k_get_fan_status(int fan)
+{
+ SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
+ int rc;
+
+ regs.eax = I8K_SMM_GET_FAN;
+ regs.ebx = fan & 0xff;
+ if ((rc=i8k_smm(&regs)) < 0) {
+ return rc;
+ }
+
+ return (regs.eax & 0xff);
+}
+
+/*
+ * Read the fan speed in RPM.
+ */
+static int i8k_get_fan_speed(int fan)
+{
+ SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
+ int rc;
+
+ regs.eax = I8K_SMM_GET_SPEED;
+ regs.ebx = fan & 0xff;
+ if ((rc=i8k_smm(&regs)) < 0) {
+ return rc;
+ }
+
+ return (regs.eax & 0xffff) * I8K_FAN_MULT;
+}
+
+/*
+ * Set the fan speed (off, low, high). Returns the new fan status.
+ */
+static int i8k_set_fan(int fan, int speed)
+{
+ SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
+ int rc;
+
+ speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
+
+ regs.eax = I8K_SMM_SET_FAN;
+ regs.ebx = (fan & 0xff) | (speed << 8);
+ if ((rc=i8k_smm(&regs)) < 0) {
+ return rc;
+ }
+
+ return (i8k_get_fan_status(fan));
+}
+
+/*
+ * Read the cpu temperature.
+ */
+static int i8k_get_cpu_temp(void)
+{
+ SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
+ int rc;
+ int temp;
+
+#ifdef I8K_TEMPERATURE_BUG
+ static int prev = 0;
+#endif
+
+ regs.eax = I8K_SMM_GET_TEMP;
+ if ((rc=i8k_smm(&regs)) < 0) {
+ return rc;
+ }
+ temp = regs.eax & 0xff;
+
+#ifdef I8K_TEMPERATURE_BUG
+ /*
+ * Sometimes the temperature sensor returns 0x99, which is out of range.
+ * In this case we return (once) the previous cached value. For example:
+ # 1003655137 00000058 00005a4b
+ # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
+ # 1003655139 00000054 00005c52
+ */
+ if (temp > I8K_MAX_TEMP) {
+ temp = prev;
+ prev = I8K_MAX_TEMP;
+ } else {
+ prev = temp;
+ }
+#endif
+
+ return temp;
+}
+
+static int i8k_get_dell_signature(void)
+{
+ SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
+ int rc;
+
+ regs.eax = I8K_SMM_GET_DELL_SIG;
+ if ((rc=i8k_smm(&regs)) < 0) {
+ return rc;
+ }
+
+ if ((regs.eax == 1145651527) && (regs.edx == 1145392204)) {
+ return 0;
+ } else {
+ return -1;
+ }
+}
+
+static int i8k_ioctl(struct inode *ip, struct file *fp, unsigned int cmd,
+ unsigned long arg)
+{
+ int val;
+ int speed;
+ unsigned char buff[16];
+ int __user *argp = (int __user *)arg;
+
+ if (!argp)
+ return -EINVAL;
+
+ switch (cmd) {
+ case I8K_BIOS_VERSION:
+ val = i8k_get_bios_version();
+ break;
+
+ case I8K_MACHINE_ID:
+ memset(buff, 0, 16);
+ val = i8k_get_serial_number(buff);
+ break;
+
+ case I8K_FN_STATUS:
+ val = i8k_get_fn_status();
+ break;
+
+ case I8K_POWER_STATUS:
+ val = i8k_get_power_status();
+ break;
+
+ case I8K_GET_TEMP:
+ val = i8k_get_cpu_temp();
+ break;
+
+ case I8K_GET_SPEED:
+ if (copy_from_user(&val, argp, sizeof(int))) {
+ return -EFAULT;
+ }
+ val = i8k_get_fan_speed(val);
+ break;
+
+ case I8K_GET_FAN:
+ if (copy_from_user(&val, argp, sizeof(int))) {
+ return -EFAULT;
+ }
+ val = i8k_get_fan_status(val);
+ break;
+
+ case I8K_SET_FAN:
+ if (restricted && !capable(CAP_SYS_ADMIN)) {
+ return -EPERM;
+ }
+ if (copy_from_user(&val, argp, sizeof(int))) {
+ return -EFAULT;
+ }
+ if (copy_from_user(&speed, argp+1, sizeof(int))) {
+ return -EFAULT;
+ }
+ val = i8k_set_fan(val, speed);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ if (val < 0) {
+ return val;
+ }
+
+ switch (cmd) {
+ case I8K_BIOS_VERSION:
+ if (copy_to_user(argp, &val, 4)) {
+ return -EFAULT;
+ }
+ break;
+ case I8K_MACHINE_ID:
+ if (copy_to_user(argp, buff, 16)) {
+ return -EFAULT;
+ }
+ break;
+ default:
+ if (copy_to_user(argp, &val, sizeof(int))) {
+ return -EFAULT;
+ }
+ break;
+ }
+
+ return 0;
+}
+
+/*
+ * Print the information for /proc/i8k.
+ */
+static int i8k_get_info(char *buffer, char **start, off_t fpos, int length)
+{
+ int n, fn_key, cpu_temp, ac_power;
+ int left_fan, right_fan, left_speed, right_speed;
+
+ cpu_temp = i8k_get_cpu_temp(); /* 11100 µs */
+ left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 µs */
+ right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 µs */
+ left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 µs */
+ right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 µs */
+ fn_key = i8k_get_fn_status(); /* 750 µs */
+ if (power_status) {
+ ac_power = i8k_get_power_status(); /* 14700 µs */
+ } else {
+ ac_power = -1;
+ }
+
+ /*
+ * Info:
+ *
+ * 1) Format version (this will change if format changes)
+ * 2) BIOS version
+ * 3) BIOS machine ID
+ * 4) Cpu temperature
+ * 5) Left fan status
+ * 6) Right fan status
+ * 7) Left fan speed
+ * 8) Right fan speed
+ * 9) AC power
+ * 10) Fn Key status
+ */
+ n = sprintf(buffer, "%s %s %s %d %d %d %d %d %d %d\n",
+ I8K_PROC_FMT,
+ bios_version,
+ serial_number,
+ cpu_temp,
+ left_fan,
+ right_fan,
+ left_speed,
+ right_speed,
+ ac_power,
+ fn_key);
+
+ return n;
+}
+
+static ssize_t i8k_read(struct file *f, char __user *buffer, size_t len, loff_t *fpos)
+{
+ int n;
+ char info[128];
+
+ n = i8k_get_info(info, NULL, 0, 128);
+ if (n <= 0) {
+ return n;
+ }
+
+ if (*fpos >= n) {
+ return 0;
+ }
+
+ if ((*fpos + len) >= n) {
+ len = n - *fpos;
+ }
+
+ if (copy_to_user(buffer, info, len) != 0) {
+ return -EFAULT;
+ }
+
+ *fpos += len;
+ return len;
+}
+
+static char* __init string_trim(char *s, int size)
+{
+ int len;
+ char *p;
+
+ if ((len = strlen(s)) > size) {
+ len = size;
+ }
+
+ for (p=s+len-1; len && (*p==' '); len--,p--) {
+ *p = '\0';
+ }
+
+ return s;
+}
+
+/* DMI code, stolen from arch/i386/kernel/dmi_scan.c */
+
+/*
+ * |<-- dmi->length -->|
+ * | |
+ * |dmi header s=N | string1,\0, ..., stringN,\0, ..., \0
+ * | |
+ * +-----------------------+
+ */
+static char* __init dmi_string(DMIHeader *dmi, u8 s)
+{
+ u8 *p;
+
+ if (!s) {
+ return "";
+ }
+ s--;
+
+ p = (u8 *)dmi + dmi->length;
+ while (s > 0) {
+ p += strlen(p);
+ p++;
+ s--;
+ }
+
+ return p;
+}
+
+static void __init dmi_decode(DMIHeader *dmi)
+{
+ u8 *data = (u8 *) dmi;
+ char *p;
+
+#ifdef I8K_DEBUG
+ int i;
+ printk("%08x ", (int)data);
+ for (i=0; i<data[1] && i<64; i++) {
+ printk("%02x ", data[i]);
+ }
+ printk("\n");
+#endif
+
+ switch (dmi->type) {
+ case 0: /* BIOS Information */
+ p = dmi_string(dmi,data[5]);
+ if (*p) {
+ strlcpy(bios_version, p, sizeof(bios_version));
+ string_trim(bios_version, sizeof(bios_version));
+ }
+ break;
+ case 1: /* System Information */
+ p = dmi_string(dmi,data[4]);
+ if (*p) {
+ strlcpy(system_vendor, p, sizeof(system_vendor));
+ string_trim(system_vendor, sizeof(system_vendor));
+ }
+ p = dmi_string(dmi,data[5]);
+ if (*p) {
+ strlcpy(product_name, p, sizeof(product_name));
+ string_trim(product_name, sizeof(product_name));
+ }
+ p = dmi_string(dmi,data[7]);
+ if (*p) {
+ strlcpy(serial_number, p, sizeof(serial_number));
+ string_trim(serial_number, sizeof(serial_number));
+ }
+ break;
+ }
+}
+
+static int __init dmi_table(u32 base, int len, int num, void (*fn)(DMIHeader*))
+{
+ u8 *buf;
+ u8 *data;
+ DMIHeader *dmi;
+ int i = 1;
+
+ buf = ioremap(base, len);
+ if (buf == NULL) {
+ return -1;
+ }
+ data = buf;
+
+ /*
+ * Stop when we see al the items the table claimed to have
+ * or we run off the end of the table (also happens)
+ */
+ while ((i<num) && ((data-buf) < len)) {
+ dmi = (DMIHeader *)data;
+ /*
+ * Avoid misparsing crud if the length of the last
+ * record is crap
+ */
+ if ((data-buf+dmi->length) >= len) {
+ break;
+ }
+ fn(dmi);
+ data += dmi->length;
+ /*
+ * Don't go off the end of the data if there is
+ * stuff looking like string fill past the end
+ */
+ while (((data-buf) < len) && (*data || data[1])) {
+ data++;
+ }
+ data += 2;
+ i++;
+ }
+ iounmap(buf);
+
+ return 0;
+}
+
+static int __init dmi_iterate(void (*decode)(DMIHeader *))
+{
+ unsigned char buf[20];
+ void __iomem *p = ioremap(0xe0000, 0x20000), *q;
+
+ if (!p)
+ return -1;
+
+ for (q = p; q < p + 0x20000; q += 16) {
+ memcpy_fromio(buf, q, 20);
+ if (memcmp(buf, "_DMI_", 5)==0) {
+ u16 num = buf[13]<<8 | buf[12];
+ u16 len = buf [7]<<8 | buf [6];
+ u32 base = buf[11]<<24 | buf[10]<<16 | buf[9]<<8 | buf[8];
+#ifdef I8K_DEBUG
+ printk(KERN_INFO "DMI %d.%d present.\n",
+ buf[14]>>4, buf[14]&0x0F);
+ printk(KERN_INFO "%d structures occupying %d bytes.\n",
+ buf[13]<<8 | buf[12],
+ buf [7]<<8 | buf[6]);
+ printk(KERN_INFO "DMI table at 0x%08X.\n",
+ buf[11]<<24 | buf[10]<<16 | buf[9]<<8 | buf[8]);
+#endif
+ if (dmi_table(base, len, num, decode)==0) {
+ iounmap(p);
+ return 0;
+ }
+ }
+ }
+ iounmap(p);
+ return -1;
+}
+/* end of DMI code */
+
+/*
+ * Get DMI information.
+ */
+static int __init i8k_dmi_probe(void)
+{
+ char **p;
+
+ if (dmi_iterate(dmi_decode) != 0) {
+ printk(KERN_INFO "i8k: unable to get DMI information\n");
+ return -ENODEV;
+ }
+
+ if (strncmp(system_vendor,DELL_SIGNATURE,strlen(DELL_SIGNATURE)) != 0) {
+ printk(KERN_INFO "i8k: not running on a Dell system\n");
+ return -ENODEV;
+ }
+
+ for (p=supported_models; ; p++) {
+ if (!*p) {
+ printk(KERN_INFO "i8k: unsupported model: %s\n", product_name);
+ return -ENODEV;
+ }
+ if (strncmp(product_name,*p,strlen(*p)) == 0) {
+ break;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Probe for the presence of a supported laptop.
+ */
+static int __init i8k_probe(void)
+{
+ char buff[4];
+ int version;
+ int smm_found = 0;
+
+ /*
+ * Get DMI information
+ */
+ if (i8k_dmi_probe() != 0) {
+ printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n",
+ system_vendor, product_name, bios_version);
+ }
+
+ /*
+ * Get SMM Dell signature
+ */
+ if (i8k_get_dell_signature() != 0) {
+ printk(KERN_INFO "i8k: unable to get SMM Dell signature\n");
+ } else {
+ smm_found = 1;
+ }
+
+ /*
+ * Get SMM BIOS version.
+ */
+ version = i8k_get_bios_version();
+ if (version <= 0) {
+ printk(KERN_INFO "i8k: unable to get SMM BIOS version\n");
+ } else {
+ smm_found = 1;
+ buff[0] = (version >> 16) & 0xff;
+ buff[1] = (version >> 8) & 0xff;
+ buff[2] = (version) & 0xff;
+ buff[3] = '\0';
+ /*
+ * If DMI BIOS version is unknown use SMM BIOS version.
+ */
+ if (bios_version[0] == '?') {
+ strcpy(bios_version, buff);
+ }
+ /*
+ * Check if the two versions match.
+ */
+ if (strncmp(buff,bios_version,sizeof(bios_version)) != 0) {
+ printk(KERN_INFO "i8k: BIOS version mismatch: %s != %s\n",
+ buff, bios_version);
+ }
+ }
+
+ if (!smm_found && !force) {
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+#ifdef MODULE
+static
+#endif
+int __init i8k_init(void)
+{
+ struct proc_dir_entry *proc_i8k;
+
+ /* Are we running on an supported laptop? */
+ if (i8k_probe() != 0) {
+ return -ENODEV;
+ }
+
+ /* Register the proc entry */
+ proc_i8k = create_proc_info_entry("i8k", 0, NULL, i8k_get_info);
+ if (!proc_i8k) {
+ return -ENOENT;
+ }
+ proc_i8k->proc_fops = &i8k_fops;
+ proc_i8k->owner = THIS_MODULE;
+
+ printk(KERN_INFO
+ "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
+ I8K_VERSION);
+
+ return 0;
+}
+
+#ifdef MODULE
+int init_module(void)
+{
+ return i8k_init();
+}
+
+void cleanup_module(void)
+{
+ /* Remove the proc entry */
+ remove_proc_entry("i8k", NULL);
+
+ printk(KERN_INFO "i8k: module unloaded\n");
+}
+#endif
+
+/* end of file */