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path: root/drivers/hwmon/fschmd.c
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Diffstat (limited to 'drivers/hwmon/fschmd.c')
-rw-r--r--drivers/hwmon/fschmd.c90
1 files changed, 88 insertions, 2 deletions
diff --git a/drivers/hwmon/fschmd.c b/drivers/hwmon/fschmd.c
index d427ea5623fb..b7c9eef0f928 100644
--- a/drivers/hwmon/fschmd.c
+++ b/drivers/hwmon/fschmd.c
@@ -41,6 +41,7 @@
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
+#include <linux/dmi.h>
/* Addresses to scan */
static unsigned short normal_i2c[] = { 0x73, I2C_CLIENT_END };
@@ -210,6 +211,13 @@ struct fschmd_data {
u8 fan_ripple[6]; /* divider for rps */
};
+/* Global variables to hold information read from special DMI tables, which are
+ available on FSC machines with an fscher or later chip. */
+static int dmi_mult[3] = { 490, 200, 100 };
+static int dmi_offset[3] = { 0, 0, 0 };
+static int dmi_vref = -1;
+
+
/*
* Sysfs attr show / store functions
*/
@@ -221,8 +229,13 @@ static ssize_t show_in_value(struct device *dev,
int index = to_sensor_dev_attr(devattr)->index;
struct fschmd_data *data = fschmd_update_device(dev);
- return sprintf(buf, "%d\n", (data->volt[index] *
- max_reading[index] + 128) / 255);
+ /* fscher / fschrc - 1 as data->kind is an array index, not a chips */
+ if (data->kind == (fscher - 1) || data->kind >= (fschrc - 1))
+ return sprintf(buf, "%d\n", (data->volt[index] * dmi_vref *
+ dmi_mult[index]) / 255 + dmi_offset[index]);
+ else
+ return sprintf(buf, "%d\n", (data->volt[index] *
+ max_reading[index] + 128) / 255);
}
@@ -525,6 +538,68 @@ static struct sensor_device_attribute fschmd_fan_attr[] = {
* Real code
*/
+/* DMI decode routine to read voltage scaling factors from special DMI tables,
+ which are available on FSC machines with an fscher or later chip. */
+static void fschmd_dmi_decode(const struct dmi_header *header)
+{
+ int i, mult[3] = { 0 }, offset[3] = { 0 }, vref = 0, found = 0;
+
+ /* dmi code ugliness, we get passed the address of the contents of
+ a complete DMI record, but in the form of a dmi_header pointer, in
+ reality this address holds header->length bytes of which the header
+ are the first 4 bytes */
+ u8 *dmi_data = (u8 *)header;
+
+ /* We are looking for OEM-specific type 185 */
+ if (header->type != 185)
+ return;
+
+ /* we are looking for what Siemens calls "subtype" 19, the subtype
+ is stored in byte 5 of the dmi block */
+ if (header->length < 5 || dmi_data[4] != 19)
+ return;
+
+ /* After the subtype comes 1 unknown byte and then blocks of 5 bytes,
+ consisting of what Siemens calls an "Entity" number, followed by
+ 2 16-bit words in LSB first order */
+ for (i = 6; (i + 4) < header->length; i += 5) {
+ /* entity 1 - 3: voltage multiplier and offset */
+ if (dmi_data[i] >= 1 && dmi_data[i] <= 3) {
+ /* Our in sensors order and the DMI order differ */
+ const int shuffle[3] = { 1, 0, 2 };
+ int in = shuffle[dmi_data[i] - 1];
+
+ /* Check for twice the same entity */
+ if (found & (1 << in))
+ return;
+
+ mult[in] = dmi_data[i + 1] | (dmi_data[i + 2] << 8);
+ offset[in] = dmi_data[i + 3] | (dmi_data[i + 4] << 8);
+
+ found |= 1 << in;
+ }
+
+ /* entity 7: reference voltage */
+ if (dmi_data[i] == 7) {
+ /* Check for twice the same entity */
+ if (found & 0x08)
+ return;
+
+ vref = dmi_data[i + 1] | (dmi_data[i + 2] << 8);
+
+ found |= 0x08;
+ }
+ }
+
+ if (found == 0x0F) {
+ for (i = 0; i < 3; i++) {
+ dmi_mult[i] = mult[i] * 10;
+ dmi_offset[i] = offset[i] * 10;
+ }
+ dmi_vref = vref;
+ }
+}
+
static int fschmd_detect(struct i2c_adapter *adapter, int address, int kind)
{
struct i2c_client *client;
@@ -586,6 +661,17 @@ static int fschmd_detect(struct i2c_adapter *adapter, int address, int kind)
data->temp_max[2] = 50 + 128;
}
+ /* Read the special DMI table for fscher and newer chips */
+ if (kind == fscher || kind >= fschrc) {
+ dmi_walk(fschmd_dmi_decode);
+ if (dmi_vref == -1) {
+ printk(KERN_WARNING FSCHMD_NAME
+ ": Couldn't get voltage scaling factors from "
+ "BIOS DMI table, using builtin defaults\n");
+ dmi_vref = 33;
+ }
+ }
+
/* i2c kind goes from 1-5, we want from 0-4 to address arrays */
data->kind = kind - 1;
strlcpy(client->name, client_names[data->kind], I2C_NAME_SIZE);