[ltp] [patch 3/3] ibm-acpi: Implement direct-ec-access thermal reading modes for up to 16 sensors
Henrique de Moraes Holschuh
linux-thinkpad@linux-thinkpad.org
Wed, 27 Sep 2006 20:53:38 -0300
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.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: borislav@users.sourceforge.net
---
This patch depends on dmi-decode-and-save-oem-string-information.patch
from the 2.6.18-mm1 tree.
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.
Documentation/ibm-acpi.txt | 55 ++++++++++++++++++++------
drivers/acpi/ibm_acpi.c | 94 +++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 133 insertions(+), 16 deletions(-)
Index: 2.6.18/Documentation/ibm-acpi.txt
===================================================================
--- 2.6.18.orig/Documentation/ibm-acpi.txt
+++ 2.6.18/Documentation/ibm-acpi.txt
@@ -430,25 +430,56 @@ Temperature sensors -- /proc/acpi/ibm/th
Most ThinkPads include six or more separate temperature sensors but
only expose the CPU temperature through the standard ACPI methods.
-This feature shows readings from up to eight different sensors. Some
-readings may not be valid, e.g. may show large negative values. For
-example, on the X40, a typical output may be:
+This feature shows readings from up to eight different sensors on older
+ThinkPads, and it has experimental support for up to sixteen different
+sensors on newer ThinkPads. Readings from sensors that are not available
+return -128.
+No commands can be written to this file.
+
+EXPERIMENTAL: The 16-sensors feature is marked EXPERIMENTAL because the
+implementation directly accesses hardware registers and may not work as
+expected. USE WITH CAUTION! To use this feature, you need to supply the
+experimental=1 parameter when loading the module. When EXPERIMENTAL
+mode is enabled, reading the first 8 sensors on newer ThinkPads will
+also use an new experimental thermal sensor access mode.
+
+For example, on the X40, a typical output may be:
temperatures: 42 42 45 41 36 -128 33 -128
-Thomas Gruber took his R51 apart and traced all six active sensors in
-his laptop (the location of sensors may vary on other models):
+EXPERIMENTAL: On the T43/p, a typical output may be:
+temperatures: 48 48 36 52 38 -128 31 -128 48 52 48 -128 -128 -128 -128 -128
+
+The mapping of thermal sensors to physical locations varies depending on
+system-board model (and thus, on ThinkPad model).
+
+http://thinkwiki.org/wiki/Thermal_Sensors is a public wiki page that
+tries to track down these locations for various models.
+
+Most (newer?) models seem to follow this pattern:
1: CPU
-2: Mini PCI Module
-3: HDD
+2: (depends on model)
+3: (depends on model)
4: GPU
-5: Battery
-6: N/A
-7: Battery
-8: N/A
+5: Main battery: main sensor
+6: Bay battery: main sensor
+7: Main battery: secondary sensor
+8: Bay battery: secondary sensor
+9-15: (depends on model)
+
+For the R51 (source: Thomas Gruber):
+2: Mini-PCI
+3: Internal HDD
+
+For the T43, T43/p (source: Shmidoax/Thinkwiki.org)
+http://thinkwiki.org/wiki/Image:T43-thermal-sensors.jpg
+2: System board, left side (near PCMCIA slot), reported as HDAPS temp
+3: PCMCIA slot
+9: MCH (northbridge) to DRAM Bus
+10: ICH (southbridge), under Mini-PCI card, under touchpad
+11: Power regulator, underside of system board, below F2 key
-No commands can be written to this file.
EXPERIMENTAL: Embedded controller reigster dump -- /proc/acpi/ibm/ecdump
------------------------------------------------------------------------
Index: 2.6.18/drivers/acpi/ibm_acpi.c
===================================================================
--- 2.6.18.orig/drivers/acpi/ibm_acpi.c
+++ 2.6.18/drivers/acpi/ibm_acpi.c
@@ -79,6 +79,7 @@
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <asm/uaccess.h>
+#include <linux/dmi.h>
#include <acpi/acpi_drivers.h>
#include <acpi/acnamesp.h>
@@ -220,8 +221,12 @@ 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 */
};
+static int ibm_thinkpad_ec_found;
+
struct ibm_struct {
char *name;
char param[32];
@@ -1282,7 +1287,53 @@ static enum thermal_access_mode thermal_
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;
@@ -1301,13 +1352,25 @@ static int thermal_init(void)
static int thermal_read(char *p)
{
int len = 0;
- int i, t;
- s8 tmp[8];
+ int i, t, n;
+ s8 tmp[16];
char tmpi[] = "TMPi";
len += sprintf(p + len, "temperatures:\t");
switch(thermal_read_mode) {
+ case IBMACPI_THERMAL_TPEC_16:
+ for (i = 0; i < 8; i++)
+ if (!acpi_ec_read(0xC0 + i, &tmp[i+8]))
+ return -EIO;
+ /* fallthrough */
+ case IBMACPI_THERMAL_TPEC_8:
+ for (i = 0; i < 8; i++)
+ if (!acpi_ec_read(0x78 + i, &tmp[i]))
+ return -EIO;
+ n = (thermal_read_mode == IBMACPI_THERMAL_TPEC_16) ? 15 : 7;
+ break;
+
case IBMACPI_THERMAL_ACPI_UPDT:
if (!acpi_evalf(ec_handle, NULL, "UPDT", "v"))
return -EIO;
@@ -1317,6 +1380,7 @@ static int thermal_read(char *p)
return -EIO;
tmp[i] = (t - 2732 + 5) / 10;
}
+ n = 7;
break;
case IBMACPI_THERMAL_ACPI_TMP07:
@@ -1326,6 +1390,7 @@ static int thermal_read(char *p)
return -EIO;
tmp[i] = t;
}
+ n = 7;
break;
case IBMACPI_THERMAL_NONE:
@@ -1334,7 +1399,7 @@ static int thermal_read(char *p)
return len;
}
- for (i = 0; i < 7; i++)
+ for (i = 0; i < n ; i++)
len += sprintf(p + len, "%d ", tmp[i]);
len += sprintf(p + len, "%d\n", tmp[i]);
@@ -1996,6 +2061,24 @@ 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;
@@ -2015,6 +2098,9 @@ 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);
--
"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond
where the shadows lie." -- The Silicon Valley Tarot
Henrique Holschuh