Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
---
drivers/hwmon/Kconfig | 10 +++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/tsod.c | 195 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 206 insertions(+)
create mode 100644 drivers/hwmon/tsod.c
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 89ac1cb..96edb87 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1462,6 +1462,16 @@ config SENSORS_MC13783_ADC
help
Support for the A/D converter on MC13783 and MC13892 PMIC.
+config SENSORS_TSOD
+ tristate "Temperature Sensor On DIMM (TSOD)"
+ depends on I2C
+ help
+ If you say yes here you get support for the integrated temperature
+ sensors on newer DIMMs that comply with JESD21-C.
+
+ This driver can also be built as a module. If so, the module
+ will be called tsod.
+
if ACPI
comment "ACPI drivers"
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 8d6d97e..439ef1f 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -134,6 +134,7 @@ obj-$(CONFIG_SENSORS_W83L785TS) += w83l785ts.o
obj-$(CONFIG_SENSORS_W83L786NG) += w83l786ng.o
obj-$(CONFIG_SENSORS_WM831X) += wm831x-hwmon.o
obj-$(CONFIG_SENSORS_WM8350) += wm8350-hwmon.o
+obj-$(CONFIG_SENSORS_TSOD) += tsod.o
obj-$(CONFIG_PMBUS) += pmbus/
diff --git a/drivers/hwmon/tsod.c b/drivers/hwmon/tsod.c
new file mode 100644
index 0000000..f7bb070
--- /dev/null
+++ b/drivers/hwmon/tsod.c
@@ -0,0 +1,195 @@
+/*
+ * drivers/hwmon/tsod.c - Temperaure Sensor On DIMM
+ *
+ * Copyright (C) 2013 Andrew Lutomirski <luto@xxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License v2 as published by the
+ * Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
+ *
+ * The official reference for these devices is JEDEC Standard No. 21-C,
+ * which is available for free from www.jedec.org.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/slab.h>
+
+/* Registers */
+#define TSOD_CURRENT_TEMP 5
+#define TSOD_VENDOR 6
+#define TSOD_DEVICE 7
+
+/*
+ * This driver does not program the trip points, etc. -- this is done by
+ * firmware, and the memory controller probably wants the defaults preserved.
+ */
+
+struct tsod_priv {
+ struct i2c_client *client;
+ struct device *hwmondev;
+};
+
+static ssize_t show_name(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "TSOD\n");
+}
+
+static ssize_t show_label(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "DIMM Temperature\n");
+}
+
+static ssize_t show_temperature(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct tsod_priv *priv = dev_get_drvdata(dev->parent);
+ int temp, raw;
+
+ raw = i2c_smbus_read_word_swapped(priv->client, TSOD_CURRENT_TEMP);
+ if (raw < 0)
+ return raw;
+
+ /*
+ * The three high bits are undefined and the rest is twos-complement.
+ * Use a sign-extending right shift to propagate the sign bit.
+ */
+ temp = ((s16)((s16)raw << 3) >> 3);
+
+ /*
+ * The value is in units of 0.0625 degrees, but we want it in
+ * units of 0.001 degrees.
+ */
+ return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(temp * 625, 10));
+}
+
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temperature, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL, 0);
+
+static struct attribute *tsod_hwmon_attributes[] = {
+ &dev_attr_name.attr,
+ &sensor_dev_attr_temp1_input.dev_attr.attr,
+ &sensor_dev_attr_temp1_label.dev_attr.attr,
+
+ NULL,
+};
+
+static const struct attribute_group tsod_hwmon_attr_group = {
+ .attrs = tsod_hwmon_attributes,
+};
+
+static int tsod_detect(struct i2c_client *client, struct i2c_board_info *info)
+{
+ struct i2c_adapter *adapter = client->adapter;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_WORD_DATA))
+ return -ENODEV;
+
+ strlcpy(info->type, "tsod", I2C_NAME_SIZE);
+ return 0;
+}
+
+static int tsod_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int ret;
+ struct tsod_priv *priv;
+
+ /* Sanity check the address */
+ if ((client->addr & 0x78) != 0x18)
+ return -ENODEV;
+
+ /* Sanity check: make sure we can read the temperature. */
+ ret = i2c_smbus_read_word_swapped(client, TSOD_CURRENT_TEMP);
+ if (ret < 0)
+ return -ENODEV;
+
+ priv = kzalloc(sizeof(struct tsod_priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->client = client;
+
+ priv->hwmondev = hwmon_device_register(&client->dev);
+ if (IS_ERR(priv->hwmondev)) {
+ ret = PTR_ERR(priv->hwmondev);
+ goto err_free;
+ }
+
+ i2c_set_clientdata(client, priv);
+
+ ret = sysfs_create_group(&priv->hwmondev->kobj, &tsod_hwmon_attr_group);
+ if (ret)
+ goto err_unreg;
+
+ return 0;
+
+err_unreg:
+ hwmon_device_unregister(&client->dev);
+
+err_free:
+ kfree(priv);
+ i2c_set_clientdata(client, 0);
+ return ret;
+}
+
+static int tsod_remove(struct i2c_client *client)
+{
+ struct tsod_priv *priv = i2c_get_clientdata(client);
+
+ sysfs_remove_group(&priv->hwmondev->kobj, &tsod_hwmon_attr_group);
+ hwmon_device_unregister(priv->hwmondev);
+ kfree(priv);
+ return 0;
+}
+
+static const unsigned short tsod_addresses[] = {
+ 0x18, 0x19, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, I2C_CLIENT_END
+};
+
+static const struct i2c_device_id tsod_id[] = {
+ { "tsod", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, tsod_id);
+
+static struct i2c_driver tsod_driver = {
+ .driver = {
+ .name = "tsod",
+ .owner = THIS_MODULE,
+ },
+ .probe = tsod_probe,
+ .remove = tsod_remove,
+ .id_table = tsod_id,
+
+ /*
+ * We do not claim I2C_CLASS_SPD -- there are other devices
+ * on, e.g., the i2c_i801 bus that have these addresses.
+ * Instead we let the dimm-bus code instantiate us.
+ */
+
+ .detect = tsod_detect,
+ .address_list = tsod_addresses,
+};
+
+module_i2c_driver(tsod_driver);
+
+MODULE_AUTHOR("Andrew Lutomirski <luto@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Temperaure Sensor On DIMM");
+MODULE_LICENSE("GPL");
--
1.8.1.4
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