linux-surface/patches/6.7/0006-surface-sam.patch

From fb7e9294f3970a450b891c2cc7b2195861d454e3 Mon Sep 17 00:00:00 2001
From: Maximilian Luz <luzmaximilian@gmail.com>
Date: Sun, 22 Oct 2023 14:57:11 +0200
Subject: [PATCH] platform/surface: aggregator_registry: Add support for
 Surface Laptop Go 3

Add SAM client device nodes for the Surface Laptop Go 3. It seems to use
the same SAM client devices as the Surface Laptop Go 1 and 2, so re-use
their node group.

Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Patchset: surface-sam
---
 drivers/platform/surface/surface_aggregator_registry.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/platform/surface/surface_aggregator_registry.c b/drivers/platform/surface/surface_aggregator_registry.c
index aeb3feae40ff..2bc4977037fc 100644
--- a/drivers/platform/surface/surface_aggregator_registry.c
+++ b/drivers/platform/surface/surface_aggregator_registry.c
@@ -367,6 +367,9 @@ static const struct acpi_device_id ssam_platform_hub_match[] = {
 	/* Surface Laptop Go 2 */
 	{ "MSHW0290", (unsigned long)ssam_node_group_slg1 },
 
+	/* Surface Laptop Go 3 */
+	{ "MSHW0440", (unsigned long)ssam_node_group_slg1 },
+
 	/* Surface Laptop Studio */
 	{ "MSHW0123", (unsigned long)ssam_node_group_sls },
 
-- 
2.43.0

From 2de16abc5d0d2334e2935b1bdb3667a95d0009f2 Mon Sep 17 00:00:00 2001
From: Maximilian Luz <luzmaximilian@gmail.com>
Date: Mon, 20 Nov 2023 19:47:00 +0100
Subject: [PATCH] platform/surface: aggregator_registry: Add support for
 Surface Laptop Studio 2

Add SAM client device nodes for the Surface Laptop Studio 2 (SLS2). The
SLS2 is quite similar to the SLS1, but it does not provide the touchpad
as a SAM-HID device. Therefore, add a new node group for the SLS2 and
update the comments accordingly

Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Patchset: surface-sam
---
 .../surface/surface_aggregator_registry.c     | 25 ++++++++++++++++---
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/platform/surface/surface_aggregator_registry.c b/drivers/platform/surface/surface_aggregator_registry.c
index 2bc4977037fc..26cb6229ad16 100644
--- a/drivers/platform/surface/surface_aggregator_registry.c
+++ b/drivers/platform/surface/surface_aggregator_registry.c
@@ -247,8 +247,8 @@ static const struct software_node *ssam_node_group_sl5[] = {
 	NULL,
 };
 
-/* Devices for Surface Laptop Studio. */
-static const struct software_node *ssam_node_group_sls[] = {
+/* Devices for Surface Laptop Studio 1. */
+static const struct software_node *ssam_node_group_sls1[] = {
 	&ssam_node_root,
 	&ssam_node_bat_ac,
 	&ssam_node_bat_main,
@@ -263,6 +263,20 @@ static const struct software_node *ssam_node_group_sls[] = {
 	NULL,
 };
 
+/* Devices for Surface Laptop Studio 2. */
+static const struct software_node *ssam_node_group_sls2[] = {
+	&ssam_node_root,
+	&ssam_node_bat_ac,
+	&ssam_node_bat_main,
+	&ssam_node_tmp_pprof,
+	&ssam_node_pos_tablet_switch,
+	&ssam_node_hid_sam_keyboard,
+	&ssam_node_hid_sam_penstash,
+	&ssam_node_hid_sam_sensors,
+	&ssam_node_hid_sam_ucm_ucsi,
+	NULL,
+};
+
 /* Devices for Surface Laptop Go. */
 static const struct software_node *ssam_node_group_slg1[] = {
 	&ssam_node_root,
@@ -370,8 +384,11 @@ static const struct acpi_device_id ssam_platform_hub_match[] = {
 	/* Surface Laptop Go 3 */
 	{ "MSHW0440", (unsigned long)ssam_node_group_slg1 },
 
-	/* Surface Laptop Studio */
-	{ "MSHW0123", (unsigned long)ssam_node_group_sls },
+	/* Surface Laptop Studio 1 */
+	{ "MSHW0123", (unsigned long)ssam_node_group_sls1 },
+
+	/* Surface Laptop Studio 2 */
+	{ "MSHW0360", (unsigned long)ssam_node_group_sls2 },
 
 	{ },
 };
-- 
2.43.0

From c06e370b5ed873b603aa0dc2faafe24a9e63b3e8 Mon Sep 17 00:00:00 2001
From: Ivor Wanders <ivor@iwanders.net>
Date: Mon, 18 Dec 2023 19:21:32 -0500
Subject: [PATCH] platform/surface: aggregator_registry: add entry for fan
 speed

Add an entry for the fan speed function.
Add this new entry to the Surface Pro 9 group.

Signed-off-by: Ivor Wanders <ivor@iwanders.net>
Link: https://github.com/linux-surface/kernel/pull/144
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com>
Patchset: surface-sam
---
 drivers/platform/surface/surface_aggregator_registry.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/platform/surface/surface_aggregator_registry.c b/drivers/platform/surface/surface_aggregator_registry.c
index 26cb6229ad16..f02a933160ff 100644
--- a/drivers/platform/surface/surface_aggregator_registry.c
+++ b/drivers/platform/surface/surface_aggregator_registry.c
@@ -74,6 +74,12 @@ static const struct software_node ssam_node_tmp_pprof = {
 	.parent = &ssam_node_root,
 };
 
+/* Fan speed function. */
+static const struct software_node ssam_node_fan_speed = {
+	.name = "ssam:01:05:01:01:01",
+	.parent = &ssam_node_root,
+};
+
 /* Tablet-mode switch via KIP subsystem. */
 static const struct software_node ssam_node_kip_tablet_switch = {
 	.name = "ssam:01:0e:01:00:01",
@@ -319,6 +325,7 @@ static const struct software_node *ssam_node_group_sp9[] = {
 	&ssam_node_bat_ac,
 	&ssam_node_bat_main,
 	&ssam_node_tmp_pprof,
+	&ssam_node_fan_speed,
 	&ssam_node_pos_tablet_switch,
 	&ssam_node_hid_kip_keyboard,
 	&ssam_node_hid_kip_penstash,
-- 
2.43.0

From 63dcbbcad69219e1487db46a5c26c1ebdd9ef6be Mon Sep 17 00:00:00 2001
From: Ivor Wanders <ivor@iwanders.net>
Date: Thu, 30 Nov 2023 20:20:24 -0500
Subject: [PATCH] hwmon: add fan speed monitoring driver for Surface devices

Adds a driver that provides read only access to the fan speed for Microsoft
Surface Pro devices. The fan speed is always regulated by the EC and cannot
be influenced directly.

Signed-off-by: Ivor Wanders <ivor@iwanders.net>
Link: https://github.com/linux-surface/kernel/pull/144
Patchset: surface-sam
---
 Documentation/hwmon/index.rst       |  1 +
 Documentation/hwmon/surface_fan.rst | 25 ++++++++
 MAINTAINERS                         |  8 +++
 drivers/hwmon/Kconfig               | 13 ++++
 drivers/hwmon/Makefile              |  1 +
 drivers/hwmon/surface_fan.c         | 93 +++++++++++++++++++++++++++++
 6 files changed, 141 insertions(+)
 create mode 100644 Documentation/hwmon/surface_fan.rst
 create mode 100644 drivers/hwmon/surface_fan.c

diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 72f4e6065bae..7c254562abd6 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -204,6 +204,7 @@ Hardware Monitoring Kernel Drivers
    smsc47m1
    sparx5-temp
    stpddc60
+   surface_fan
    sy7636a-hwmon
    tc654
    tc74
diff --git a/Documentation/hwmon/surface_fan.rst b/Documentation/hwmon/surface_fan.rst
new file mode 100644
index 000000000000..07942574c4f0
--- /dev/null
+++ b/Documentation/hwmon/surface_fan.rst
@@ -0,0 +1,25 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver surface_fan
+=========================
+
+Supported Devices:
+
+  * Microsoft Surface Pro 9
+
+Author: Ivor Wanders <ivor@iwanders.net>
+
+Description
+-----------
+
+This provides monitoring of the fan found in some Microsoft Surface Pro devices,
+like the Surface Pro 9. The fan is always controlled by the onboard controller.
+
+Sysfs interface
+---------------
+
+======================= ======= =========================================
+Name                    Perm    Description
+======================= ======= =========================================
+``fan1_input``          RO      Current fan speed in RPM.
+======================= ======= =========================================
diff --git a/MAINTAINERS b/MAINTAINERS
index a7c4cf8201e0..77eb076e77da 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14331,6 +14331,14 @@ F:	Documentation/driver-api/surface_aggregator/clients/dtx.rst
 F:	drivers/platform/surface/surface_dtx.c
 F:	include/uapi/linux/surface_aggregator/dtx.h
 
+MICROSOFT SURFACE SENSOR FAN DRIVER
+M:	Maximilian Luz <luzmaximilian@gmail.com>
+M:	Ivor Wanders <ivor@iwanders.net>
+L:	linux-hwmon@vger.kernel.org
+S:	Maintained
+F:	Documentation/hwmon/surface_fan.rst
+F:	drivers/hwmon/surface_fan.c
+
 MICROSOFT SURFACE GPE LID SUPPORT DRIVER
 M:	Maximilian Luz <luzmaximilian@gmail.com>
 L:	platform-driver-x86@vger.kernel.org
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index cf27523eed5a..1cef428c79ea 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1983,6 +1983,19 @@ config SENSORS_SFCTEMP
 	  This driver can also be built as a module.  If so, the module
 	  will be called sfctemp.
 
+config SENSORS_SURFACE_FAN
+	tristate "Surface Fan Driver"
+	depends on SURFACE_AGGREGATOR
+	help
+	  Driver that provides monitoring of the fan on Surface Pro devices that
+	  have a fan, like the Surface Pro 9.
+
+	  This makes the fan's current speed accessible through the hwmon
+	  system. It does not provide control over the fan, the firmware is
+	  responsible for that, this driver merely provides monitoring.
+
+	  Select M or Y here, if you want to be able to read the fan's speed.
+
 config SENSORS_ADC128D818
 	tristate "Texas Instruments ADC128D818"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index e84bd9685b5c..30a284fc5ab6 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -200,6 +200,7 @@ obj-$(CONFIG_SENSORS_SMSC47M1)	+= smsc47m1.o
 obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o
 obj-$(CONFIG_SENSORS_SPARX5)	+= sparx5-temp.o
 obj-$(CONFIG_SENSORS_STTS751)	+= stts751.o
+obj-$(CONFIG_SENSORS_SURFACE_FAN)+= surface_fan.o
 obj-$(CONFIG_SENSORS_SY7636A)	+= sy7636a-hwmon.o
 obj-$(CONFIG_SENSORS_AMC6821)	+= amc6821.o
 obj-$(CONFIG_SENSORS_TC74)	+= tc74.o
diff --git a/drivers/hwmon/surface_fan.c b/drivers/hwmon/surface_fan.c
new file mode 100644
index 000000000000..7c2e3ae3eb40
--- /dev/null
+++ b/drivers/hwmon/surface_fan.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Surface Fan driver for Surface System Aggregator Module. It provides access
+ * to the fan's rpm through the hwmon system.
+ *
+ * Copyright (C) 2023 Ivor Wanders <ivor@iwanders.net>
+ */
+
+#include <linux/hwmon.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/surface_aggregator/device.h>
+#include <linux/types.h>
+
+// SSAM
+SSAM_DEFINE_SYNC_REQUEST_CL_R(__ssam_fan_rpm_get, __le16, {
+	.target_category = SSAM_SSH_TC_FAN,
+	.command_id      = 0x01,
+});
+
+// hwmon
+umode_t surface_fan_hwmon_is_visible(const void *drvdata,
+				     enum hwmon_sensor_types type, u32 attr,
+				     int channel)
+{
+	return 0444;
+}
+
+static int surface_fan_hwmon_read(struct device *dev,
+				  enum hwmon_sensor_types type, u32 attr,
+				  int channel, long *val)
+{
+	struct ssam_device *sdev = dev_get_drvdata(dev);
+	int ret;
+	__le16 value;
+
+	ret = __ssam_fan_rpm_get(sdev, &value);
+	if (ret)
+		return ret;
+
+	*val = le16_to_cpu(value);
+
+	return ret;
+}
+
+static const struct hwmon_channel_info *const surface_fan_info[] = {
+	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT),
+	NULL
+};
+
+static const struct hwmon_ops surface_fan_hwmon_ops = {
+	.is_visible = surface_fan_hwmon_is_visible,
+	.read = surface_fan_hwmon_read,
+};
+
+static const struct hwmon_chip_info surface_fan_chip_info = {
+	.ops = &surface_fan_hwmon_ops,
+	.info = surface_fan_info,
+};
+
+static int surface_fan_probe(struct ssam_device *sdev)
+{
+	struct device *hdev;
+
+	hdev = devm_hwmon_device_register_with_info(&sdev->dev,
+						    "surface_fan", sdev,
+						    &surface_fan_chip_info,
+						    NULL);
+	if (IS_ERR(hdev))
+		return PTR_ERR(hdev);
+
+	return 0;
+}
+
+static const struct ssam_device_id ssam_fan_match[] = {
+	{ SSAM_SDEV(FAN, SAM, 0x01, 0x01) },
+	{},
+};
+MODULE_DEVICE_TABLE(ssam, ssam_fan_match);
+
+static struct ssam_device_driver surface_fan = {
+	.probe = surface_fan_probe,
+	.match_table = ssam_fan_match,
+	.driver = {
+		.name = "surface_fan",
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+};
+module_ssam_device_driver(surface_fan);
+
+MODULE_AUTHOR("Ivor Wanders <ivor@iwanders.net>");
+MODULE_DESCRIPTION("Fan Driver for Surface System Aggregator Module");
+MODULE_LICENSE("GPL");
-- 
2.43.0

From 5f549c253e4df330fa8f311fe151df80e199bec4 Mon Sep 17 00:00:00 2001
From: Maximilian Luz <luzmaximilian@gmail.com>
Date: Sat, 30 Dec 2023 18:07:54 +0100
Subject: [PATCH] hwmon: Add thermal sensor driver for Surface Aggregator
 Module

Some of the newer Microsoft Surface devices (such as the Surface Book
3 and Pro 9) have thermal sensors connected via the Surface Aggregator
Module (the embedded controller on those devices). Add a basic driver
to read out the temperature values of those sensors.

Link: https://github.com/linux-surface/surface-aggregator-module/issues/59
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Patchset: surface-sam
---
 drivers/hwmon/Kconfig        |  10 +++
 drivers/hwmon/Makefile       |   1 +
 drivers/hwmon/surface_temp.c | 165 +++++++++++++++++++++++++++++++++++
 3 files changed, 176 insertions(+)
 create mode 100644 drivers/hwmon/surface_temp.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 1cef428c79ea..ca20716911ad 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1996,6 +1996,16 @@ config SENSORS_SURFACE_FAN
 
 	  Select M or Y here, if you want to be able to read the fan's speed.
 
+config SENSORS_SURFACE_TEMP
+	tristate "Microsoft Surface Thermal Sensor Driver"
+	depends on SURFACE_AGGREGATOR
+	help
+	  Driver for monitoring thermal sensors connected via the Surface
+	  Aggregator Module (embedded controller) on Microsoft Surface devices.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called surface_temp.
+
 config SENSORS_ADC128D818
 	tristate "Texas Instruments ADC128D818"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 30a284fc5ab6..a6bcde6b4843 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -201,6 +201,7 @@ obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o
 obj-$(CONFIG_SENSORS_SPARX5)	+= sparx5-temp.o
 obj-$(CONFIG_SENSORS_STTS751)	+= stts751.o
 obj-$(CONFIG_SENSORS_SURFACE_FAN)+= surface_fan.o
+obj-$(CONFIG_SENSORS_SURFACE_TEMP)+= surface_temp.o
 obj-$(CONFIG_SENSORS_SY7636A)	+= sy7636a-hwmon.o
 obj-$(CONFIG_SENSORS_AMC6821)	+= amc6821.o
 obj-$(CONFIG_SENSORS_TC74)	+= tc74.o
diff --git a/drivers/hwmon/surface_temp.c b/drivers/hwmon/surface_temp.c
new file mode 100644
index 000000000000..48c3e826713f
--- /dev/null
+++ b/drivers/hwmon/surface_temp.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Thermal sensor subsystem driver for Surface System Aggregator Module (SSAM).
+ *
+ * Copyright (C) 2022-2023 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/hwmon.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+#include <linux/surface_aggregator/controller.h>
+#include <linux/surface_aggregator/device.h>
+
+
+/* -- SAM interface. -------------------------------------------------------- */
+
+SSAM_DEFINE_SYNC_REQUEST_CL_R(__ssam_tmp_get_available_sensors, __le16, {
+	.target_category = SSAM_SSH_TC_TMP,
+	.command_id      = 0x04,
+});
+
+SSAM_DEFINE_SYNC_REQUEST_MD_R(__ssam_tmp_get_temperature, __le16, {
+	.target_category = SSAM_SSH_TC_TMP,
+	.command_id      = 0x01,
+});
+
+static int ssam_tmp_get_available_sensors(struct ssam_device *sdev, s16 *sensors)
+{
+	__le16 sensors_le;
+	int status;
+
+	status = __ssam_tmp_get_available_sensors(sdev, &sensors_le);
+	if (status)
+		return status;
+
+	*sensors = le16_to_cpu(sensors_le);
+	return 0;
+}
+
+static int ssam_tmp_get_temperature(struct ssam_device *sdev, u8 iid, long *temperature)
+{
+	__le16 temp_le;
+	int status;
+
+	status = __ssam_tmp_get_temperature(sdev->ctrl, sdev->uid.target, iid, &temp_le);
+	if (status)
+		return status;
+
+	/* Convert 1/10 °K to 1/1000 °C */
+	*temperature = (le16_to_cpu(temp_le) - 2731) * 100L;
+	return 0;
+}
+
+
+/* -- Driver.---------------------------------------------------------------- */
+
+struct ssam_temp {
+	struct ssam_device *sdev;
+	s16 sensors;
+};
+
+static umode_t ssam_temp_hwmon_is_visible(const void *data,
+					  enum hwmon_sensor_types type,
+					  u32 attr, int channel)
+{
+	const struct ssam_temp *ssam_temp = data;
+
+	if (!(ssam_temp->sensors & BIT(channel)))
+		return 0;
+
+	return 0444;
+}
+
+static int ssam_temp_hwmon_read(struct device *dev,
+				enum hwmon_sensor_types type,
+				u32 attr, int channel, long *value)
+{
+	const struct ssam_temp *ssam_temp = dev_get_drvdata(dev);
+
+	return ssam_tmp_get_temperature(ssam_temp->sdev, channel + 1, value);
+}
+
+static const struct hwmon_channel_info * const ssam_temp_hwmon_info[] = {
+	HWMON_CHANNEL_INFO(chip,
+			   HWMON_C_REGISTER_TZ),
+	/* We have at most 16 thermal sensor channels. */
+	HWMON_CHANNEL_INFO(temp,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT,
+			   HWMON_T_INPUT),
+	NULL
+};
+
+static const struct hwmon_ops ssam_temp_hwmon_ops = {
+	.is_visible = ssam_temp_hwmon_is_visible,
+	.read = ssam_temp_hwmon_read,
+};
+
+static const struct hwmon_chip_info ssam_temp_hwmon_chip_info = {
+	.ops = &ssam_temp_hwmon_ops,
+	.info = ssam_temp_hwmon_info,
+};
+
+static int ssam_temp_probe(struct ssam_device *sdev)
+{
+	struct ssam_temp *ssam_temp;
+	struct device *hwmon_dev;
+	s16 sensors;
+	int status;
+
+	status = ssam_tmp_get_available_sensors(sdev, &sensors);
+	if (status)
+		return status;
+
+	ssam_temp = devm_kzalloc(&sdev->dev, sizeof(*ssam_temp), GFP_KERNEL);
+	if (!ssam_temp)
+		return -ENOMEM;
+
+	ssam_temp->sdev = sdev;
+	ssam_temp->sensors = sensors;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(&sdev->dev,
+			"surface_thermal", ssam_temp, &ssam_temp_hwmon_chip_info,
+			NULL);
+	if (IS_ERR(hwmon_dev))
+		return PTR_ERR(hwmon_dev);
+
+	return 0;
+}
+
+static const struct ssam_device_id ssam_temp_match[] = {
+	{ SSAM_SDEV(TMP, SAM, 0x00, 0x02) },
+	{ },
+};
+MODULE_DEVICE_TABLE(ssam, ssam_temp_match);
+
+static struct ssam_device_driver ssam_temp = {
+	.probe = ssam_temp_probe,
+	.match_table = ssam_temp_match,
+	.driver = {
+		.name = "surface_temp",
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+};
+module_ssam_device_driver(ssam_temp);
+
+MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>");
+MODULE_DESCRIPTION("Thermal sensor subsystem driver for Surface System Aggregator Module");
+MODULE_LICENSE("GPL");
-- 
2.43.0

From 3ccfa3b6be4794f247488f7e665ba91793ec09c7 Mon Sep 17 00:00:00 2001
From: Maximilian Luz <luzmaximilian@gmail.com>
Date: Sat, 30 Dec 2023 18:12:23 +0100
Subject: [PATCH] hwmon: surface_temp: Add support for sensor names

The thermal subsystem of the Surface Aggregator Module allows us to
query the names of the respective thermal sensors. Forward those to
userspace.

Signed-off-by: Ivor Wanders <ivor@iwanders.net>
Co-Developed-by: Maximilian Luz <luzmaximilian@gmail.com>
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Patchset: surface-sam
---
 drivers/hwmon/surface_temp.c | 113 +++++++++++++++++++++++++++++------
 1 file changed, 96 insertions(+), 17 deletions(-)

diff --git a/drivers/hwmon/surface_temp.c b/drivers/hwmon/surface_temp.c
index 48c3e826713f..4c08926139db 100644
--- a/drivers/hwmon/surface_temp.c
+++ b/drivers/hwmon/surface_temp.c
@@ -17,6 +17,27 @@
 
 /* -- SAM interface. -------------------------------------------------------- */
 
+/*
+ * Available sensors are indicated by a 16-bit bitfield, where a 1 marks the
+ * presence of a sensor. So we have at most 16 possible sensors/channels.
+ */
+#define SSAM_TMP_SENSOR_MAX_COUNT 16
+
+/*
+ * All names observed so far are 6 characters long, but there's only
+ * zeros after the name, so perhaps they can be longer. This number reflects
+ * the maximum zero-padded space observed in the returned buffer.
+ */
+#define SSAM_TMP_SENSOR_NAME_LENGTH 18
+
+struct ssam_tmp_get_name_rsp {
+	__le16 unknown1;
+	char unknown2;
+	char name[SSAM_TMP_SENSOR_NAME_LENGTH];
+} __packed;
+
+static_assert(sizeof(struct ssam_tmp_get_name_rsp) == 21);
+
 SSAM_DEFINE_SYNC_REQUEST_CL_R(__ssam_tmp_get_available_sensors, __le16, {
 	.target_category = SSAM_SSH_TC_TMP,
 	.command_id      = 0x04,
@@ -27,6 +48,11 @@ SSAM_DEFINE_SYNC_REQUEST_MD_R(__ssam_tmp_get_temperature, __le16, {
 	.command_id      = 0x01,
 });
 
+SSAM_DEFINE_SYNC_REQUEST_MD_R(__ssam_tmp_get_name, struct ssam_tmp_get_name_rsp, {
+	.target_category = SSAM_SSH_TC_TMP,
+	.command_id      = 0x0e,
+});
+
 static int ssam_tmp_get_available_sensors(struct ssam_device *sdev, s16 *sensors)
 {
 	__le16 sensors_le;
@@ -54,12 +80,37 @@ static int ssam_tmp_get_temperature(struct ssam_device *sdev, u8 iid, long *temp
 	return 0;
 }
 
+static int ssam_tmp_get_name(struct ssam_device *sdev, u8 iid, char *buf, size_t buf_len)
+{
+	struct ssam_tmp_get_name_rsp name_rsp;
+	int status;
+
+	status =  __ssam_tmp_get_name(sdev->ctrl, sdev->uid.target, iid, &name_rsp);
+	if (status)
+		return status;
+
+	/*
+	 * This should not fail unless the name in the returned struct is not
+	 * null-terminated or someone changed something in the struct
+	 * definitions above, since our buffer and struct have the same
+	 * capacity by design. So if this fails blow this up with a warning.
+	 * Since the more likely cause is that the returned string isn't
+	 * null-terminated, we might have received garbage (as opposed to just
+	 * an incomplete string), so also fail the function.
+	 */
+	status = strscpy(buf, name_rsp.name, buf_len);
+	WARN_ON(status < 0);
+
+	return status < 0 ? status : 0;
+}
+
 
 /* -- Driver.---------------------------------------------------------------- */
 
 struct ssam_temp {
 	struct ssam_device *sdev;
 	s16 sensors;
+	char names[SSAM_TMP_SENSOR_MAX_COUNT][SSAM_TMP_SENSOR_NAME_LENGTH];
 };
 
 static umode_t ssam_temp_hwmon_is_visible(const void *data,
@@ -83,33 +134,47 @@ static int ssam_temp_hwmon_read(struct device *dev,
 	return ssam_tmp_get_temperature(ssam_temp->sdev, channel + 1, value);
 }
 
+static int ssam_temp_hwmon_read_string(struct device *dev,
+				       enum hwmon_sensor_types type,
+				       u32 attr, int channel, const char **str)
+{
+	const struct ssam_temp *ssam_temp = dev_get_drvdata(dev);
+
+	*str = ssam_temp->names[channel];
+	return 0;
+}
+
 static const struct hwmon_channel_info * const ssam_temp_hwmon_info[] = {
 	HWMON_CHANNEL_INFO(chip,
 			   HWMON_C_REGISTER_TZ),
-	/* We have at most 16 thermal sensor channels. */
+	/*
+	 * We have at most SSAM_TMP_SENSOR_MAX_COUNT = 16 thermal sensor
+	 * channels.
+	 */
 	HWMON_CHANNEL_INFO(temp,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT,
-			   HWMON_T_INPUT),
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL,
+			   HWMON_T_INPUT | HWMON_T_LABEL),
 	NULL
 };
 
 static const struct hwmon_ops ssam_temp_hwmon_ops = {
 	.is_visible = ssam_temp_hwmon_is_visible,
 	.read = ssam_temp_hwmon_read,
+	.read_string = ssam_temp_hwmon_read_string,
 };
 
 static const struct hwmon_chip_info ssam_temp_hwmon_chip_info = {
@@ -122,6 +187,7 @@ static int ssam_temp_probe(struct ssam_device *sdev)
 	struct ssam_temp *ssam_temp;
 	struct device *hwmon_dev;
 	s16 sensors;
+	int channel;
 	int status;
 
 	status = ssam_tmp_get_available_sensors(sdev, &sensors);
@@ -135,6 +201,19 @@ static int ssam_temp_probe(struct ssam_device *sdev)
 	ssam_temp->sdev = sdev;
 	ssam_temp->sensors = sensors;
 
+	/* Retrieve the name for each available sensor. */
+	for (channel = 0; channel < SSAM_TMP_SENSOR_MAX_COUNT; channel++)
+	{
+		if (!(sensors & BIT(channel)))
+			continue;
+
+		status = ssam_tmp_get_name(sdev, channel + 1,
+					   ssam_temp->names[channel],
+					   SSAM_TMP_SENSOR_NAME_LENGTH);
+		if (status)
+			return status;
+	}
+
 	hwmon_dev = devm_hwmon_device_register_with_info(&sdev->dev,
 			"surface_thermal", ssam_temp, &ssam_temp_hwmon_chip_info,
 			NULL);
-- 
2.43.0

From 8ccf7b86ad270655bd1e8cd0ab8d2ff475ad0ea7 Mon Sep 17 00:00:00 2001
From: Maximilian Luz <luzmaximilian@gmail.com>
Date: Sat, 30 Dec 2023 18:21:12 +0100
Subject: [PATCH] platform/surface: aggregator_registry: Add support for
 thermal sensors on the Surface Pro 9

The Surface Pro 9 has thermal sensors connected via the Surface
Aggregator Module. Add a device node to support those.

Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Patchset: surface-sam
---
 drivers/platform/surface/surface_aggregator_registry.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/platform/surface/surface_aggregator_registry.c b/drivers/platform/surface/surface_aggregator_registry.c
index f02a933160ff..67686042e009 100644
--- a/drivers/platform/surface/surface_aggregator_registry.c
+++ b/drivers/platform/surface/surface_aggregator_registry.c
@@ -74,6 +74,12 @@ static const struct software_node ssam_node_tmp_pprof = {
 	.parent = &ssam_node_root,
 };
 
+/* Thermal sensors. */
+static const struct software_node ssam_node_tmp_sensors = {
+	.name = "ssam:01:03:01:00:02",
+	.parent = &ssam_node_root,
+};
+
 /* Fan speed function. */
 static const struct software_node ssam_node_fan_speed = {
 	.name = "ssam:01:05:01:01:01",
@@ -325,6 +331,7 @@ static const struct software_node *ssam_node_group_sp9[] = {
 	&ssam_node_bat_ac,
 	&ssam_node_bat_main,
 	&ssam_node_tmp_pprof,
+	&ssam_node_tmp_sensors,
 	&ssam_node_fan_speed,
 	&ssam_node_pos_tablet_switch,
 	&ssam_node_hid_kip_keyboard,
-- 
2.43.0