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ACPI: ibm-acpi: Implement direct-ec-access thermal reading modes for up to 16 sensors

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This patch extends ibm-acpi to support reading thermal sensors directly
through ACPI EC register access.  It uses a DMI match to detect ThinkPads
with a new-style embedded controller, that are known to have forward-
compatible register maps and use 0x00 to fill in non-used registers and
export thermal sensors at EC offsets 0x78-7F and 0xC0-C7.

Direct ACPI EC register access is implemented for 8-sensor and 16-sensor
new-style ThinkPad controller firmwares as an experimental feature.  The
code does some limited sanity checks on the temperatures read through EC
access, and will default to the old ACPI TMP0-7 mode if anything is amiss.

Userspace ABI is not changed for 8 sensors, but /proc/acpi/ibm/thermal is
extended for 16 sensors if the firmware supports 16 sensors.

A documentation update is also provided.

The information about the ThinkPad register map was determined by studying
ibm-acpi "ecdump" output from various ThinkPad models, submitted by
subscribers of the linux-thinkpad mailinglist.  Futher information was
gathered from the DSDT tables, as they describe the EC register map in
recent ThinkPads.

DSDT source shows that TMP0-7 access and direct register access are
actually the same thing on these firmwares, but unfortunately IBM never
did update their DSDT EC register map to export TMP8-TMP15 for the second
range of sensors.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
This commit is contained in:
Henrique de Moraes Holschuh
2006-11-24 11:47:08 -02:00
committed by Len Brown
parent a26f878abc
commit 60eb0b35a9
2 changed files with 139 additions and 19 deletions
Download Patch File Download Diff File Expand all files Collapse all files

93
drivers/acpi/ibm_acpi.c
View File

@@ -80,6 +80,7 @@
#include <linux/proc_fs.h>
#include <linux/backlight.h>
#include <asm/uaccess.h>
#include <linux/dmi.h>
#include <acpi/acpi_drivers.h>
#include <acpi/acnamesp.h>
@@ -221,13 +222,17 @@ enum thermal_access_mode {
IBMACPI_THERMAL_NONE = 0, /* No thermal support */
IBMACPI_THERMAL_ACPI_TMP07, /* Use ACPI TMP0-7 */
IBMACPI_THERMAL_ACPI_UPDT, /* Use ACPI TMP0-7 with UPDT */
IBMACPI_THERMAL_TPEC_8, /* Use ACPI EC regs, 8 sensors */
IBMACPI_THERMAL_TPEC_16, /* Use ACPI EC regs, 16 sensors */
};
#define IBMACPI_MAX_THERMAL_SENSORS 8 /* Max thermal sensors supported */
#define IBMACPI_MAX_THERMAL_SENSORS 16 /* Max thermal sensors supported */
struct ibm_thermal_sensors_struct {
s32 temp[IBMACPI_MAX_THERMAL_SENSORS];
};
static int ibm_thinkpad_ec_found;
struct ibm_struct {
char *name;
char param[32];
@@ -1290,7 +1295,52 @@ static enum thermal_access_mode thermal_read_mode;
static int thermal_init(void)
{
if (acpi_evalf(ec_handle, NULL, "TMP7", "qv")) {
u8 t, ta1, ta2;
int i;
int acpi_tmp7 = acpi_evalf(ec_handle, NULL, "TMP7", "qv");
if (ibm_thinkpad_ec_found && experimental) {
/*
* Direct EC access mode: sensors at registers
* 0x78-0x7F, 0xC0-0xC7. Registers return 0x00 for
* non-implemented, thermal sensors return 0x80 when
* not available
*/
ta1 = ta2 = 0;
for (i = 0; i < 8; i++) {
if (likely(acpi_ec_read(0x78 + i, &t))) {
ta1 |= t;
} else {
ta1 = 0;
break;
}
if (likely(acpi_ec_read(0xC0 + i, &t))) {
ta2 |= t;
} else {
ta1 = 0;
break;
}
}
if (ta1 == 0) {
/* This is sheer paranoia, but we handle it anyway */
if (acpi_tmp7) {
printk(IBM_ERR
"ThinkPad ACPI EC access misbehaving, "
"falling back to ACPI TMPx access mode\n");
thermal_read_mode = IBMACPI_THERMAL_ACPI_TMP07;
} else {
printk(IBM_ERR
"ThinkPad ACPI EC access misbehaving, "
"disabling thermal sensors access\n");
thermal_read_mode = IBMACPI_THERMAL_NONE;
}
} else {
thermal_read_mode =
(ta2 != 0) ?
IBMACPI_THERMAL_TPEC_16 : IBMACPI_THERMAL_TPEC_8;
}
} else if (acpi_tmp7) {
if (acpi_evalf(ec_handle, NULL, "UPDT", "qv")) {
/* 600e/x, 770e, 770x */
thermal_read_mode = IBMACPI_THERMAL_ACPI_UPDT;
@@ -1309,12 +1359,30 @@ static int thermal_init(void)
static int thermal_get_sensors(struct ibm_thermal_sensors_struct *s)
{
int i, t;
s8 tmp;
char tmpi[] = "TMPi";
if (!s)
return -EINVAL;
switch (thermal_read_mode) {
#if IBMACPI_MAX_THERMAL_SENSORS >= 16
case IBMACPI_THERMAL_TPEC_16:
for (i = 0; i < 8; i++) {
if (!acpi_ec_read(0xC0 + i, &tmp))
return -EIO;
s->temp[i + 8] = tmp * 1000;
}
/* fallthrough */
#endif
case IBMACPI_THERMAL_TPEC_8:
for (i = 0; i < 8; i++) {
if (!acpi_ec_read(0x78 + i, &tmp))
return -EIO;
s->temp[i] = tmp * 1000;
}
return (thermal_read_mode == IBMACPI_THERMAL_TPEC_16) ? 16 : 8;
case IBMACPI_THERMAL_ACPI_UPDT:
if (!acpi_evalf(ec_handle, NULL, "UPDT", "v"))
return -EIO;
@@ -2052,6 +2120,24 @@ static void acpi_ibm_exit(void)
remove_proc_entry(IBM_DIR, acpi_root_dir);
}
static int __init check_dmi_for_ec(void)
{
struct dmi_device *dev = NULL;
/*
* ThinkPad T23 or newer, A31 or newer, R50e or newer,
* X32 or newer, all Z series; Some models must have an
* up-to-date BIOS or they will not be detected.
*
* See http://thinkwiki.org/wiki/List_of_DMI_IDs
*/
while ((dev = dmi_find_device(DMI_DEV_TYPE_OEM_STRING, NULL, dev))) {
if (strstr(dev->name, "IBM ThinkPad Embedded Controller"))
return 1;
}
return 0;
}
static int __init acpi_ibm_init(void)
{
int ret, i;
@@ -2071,6 +2157,9 @@ static int __init acpi_ibm_init(void)
return -ENODEV;
}
/* Models with newer firmware report the EC in DMI */
ibm_thinkpad_ec_found = check_dmi_for_ec();
/* these handles are not required */
IBM_HANDLE_INIT(vid);
IBM_HANDLE_INIT(vid2);