platform/x86: dell-pc: Implement platform_profile

Some Dell laptops support configuration of preset fan modes through
smbios tables.

If the platform supports these fan modes, set up platform_profile to
change these modes. If not supported, skip enabling platform_profile.
Signed-off-by: Lyndon Sanche <lsanche@lyndeno.ca>
Link: https://lore.kernel.org/r/20240529174843.13226-4-lsanche@lyndeno.ca
[ij: Adjust #includes into alphabetical order]
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

MAINTAINERS

@@ -6116,6 +6116,12 @@ F:	Documentation/ABI/obsolete/procfs-i8k
 F:	drivers/hwmon/dell-smm-hwmon.c
 F:	include/uapi/linux/i8k.h
 
+DELL PC DRIVER
+M:	Lyndon Sanche <lsanche@lyndeno.ca>
+L:	platform-driver-x86@vger.kernel.org
+S:	Maintained
+F:	drivers/platform/x86/dell/dell-pc.c
+
 DELL REMOTE BIOS UPDATE DRIVER
 M:	Stuart Hayes <stuart.w.hayes@gmail.com>
 L:	platform-driver-x86@vger.kernel.org

drivers/platform/x86/dell/Kconfig

@@ -91,6 +91,19 @@ config DELL_RBTN
 	  To compile this driver as a module, choose M here: the module will
 	  be called dell-rbtn.
 
+config DELL_PC
+	tristate "Dell PC Extras"
+	default m
+	depends on ACPI
+	depends on DMI
+	depends on DELL_SMBIOS
+	select ACPI_PLATFORM_PROFILE
+	help
+	This driver adds support for controlling the fan modes via platform_profile
+	on supported Dell systems regardless of formfactor.
+	Module will simply do nothing if thermal management commands are not
+	supported.
+
 #
 # The DELL_SMBIOS driver depends on ACPI_WMI and/or DCDBAS if those
 # backends are selected. The "depends" line prevents a configuration

drivers/platform/x86/dell/Makefile

@@ -9,6 +9,7 @@ obj-$(CONFIG_DCDBAS)			+= dcdbas.o
 obj-$(CONFIG_DELL_LAPTOP)		+= dell-laptop.o
 obj-$(CONFIG_DELL_RBTN)			+= dell-rbtn.o
 obj-$(CONFIG_DELL_RBU)			+= dell_rbu.o
+obj-$(CONFIG_DELL_PC)			+= dell-pc.o
 obj-$(CONFIG_DELL_SMBIOS)		+= dell-smbios.o
 dell-smbios-objs			:= dell-smbios-base.o
 dell-smbios-$(CONFIG_DELL_SMBIOS_WMI)	+= dell-smbios-wmi.o

drivers/platform/x86/dell/dell-pc.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  Driver for Dell laptop extras
+ *
+ *  Copyright (c) Lyndon Sanche <lsanche@lyndeno.ca>
+ *
+ *  Based on documentation in the libsmbios package:
+ *  Copyright (C) 2005-2014 Dell Inc.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/dmi.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_profile.h>
+#include <linux/slab.h>
+
+#include "dell-smbios.h"
+
+static const struct dmi_system_id dell_device_table[] __initconst = {
+	{
+		.ident = "Dell Inc.",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+		},
+	},
+	{
+		.ident = "Dell Computer Corporation",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
+		},
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(dmi, dell_device_table);
+
+/* Derived from smbios-thermal-ctl
+ *
+ * cbClass 17
+ * cbSelect 19
+ * User Selectable Thermal Tables(USTT)
+ * cbArg1 determines the function to be performed
+ * cbArg1 0x0 = Get Thermal Information
+ *  cbRES1         Standard return codes (0, -1, -2)
+ *  cbRES2, byte 0  Bitmap of supported thermal modes. A mode is supported if
+ *                  its bit is set to 1
+ *     Bit 0 Balanced
+ *     Bit 1 Cool Bottom
+ *     Bit 2 Quiet
+ *     Bit 3 Performance
+ *  cbRES2, byte 1 Bitmap of supported Active Acoustic Controller (AAC) modes.
+ *                 Each mode corresponds to the supported thermal modes in
+ *                  byte 0. A mode is supported if its bit is set to 1.
+ *     Bit 0 AAC (Balanced)
+ *     Bit 1 AAC (Cool Bottom
+ *     Bit 2 AAC (Quiet)
+ *     Bit 3 AAC (Performance)
+ *  cbRes3, byte 0 Current Thermal Mode
+ *     Bit 0 Balanced
+ *     Bit 1 Cool Bottom
+ *     Bit 2 Quiet
+ *     Bit 3 Performanc
+ *  cbRes3, byte 1  AAC Configuration type
+ *          0       Global (AAC enable/disable applies to all supported USTT modes)
+ *          1       USTT mode specific
+ *  cbRes3, byte 2  Current Active Acoustic Controller (AAC) Mode
+ *     If AAC Configuration Type is Global,
+ *          0       AAC mode disabled
+ *          1       AAC mode enabled
+ *     If AAC Configuration Type is USTT mode specific (multiple bits may be set),
+ *          Bit 0 AAC (Balanced)
+ *          Bit 1 AAC (Cool Bottom
+ *          Bit 2 AAC (Quiet)
+ *          Bit 3 AAC (Performance)
+ *  cbRes3, byte 3  Current Fan Failure Mode
+ *     Bit 0 Minimal Fan Failure (at least one fan has failed, one fan working)
+ *     Bit 1 Catastrophic Fan Failure (all fans have failed)
+ *
+ * cbArg1 0x1   (Set Thermal Information), both desired thermal mode and
+ *               desired AAC mode shall be applied
+ * cbArg2, byte 0  Desired Thermal Mode to set
+ *                  (only one bit may be set for this parameter)
+ *     Bit 0 Balanced
+ *     Bit 1 Cool Bottom
+ *     Bit 2 Quiet
+ *     Bit 3 Performance
+ * cbArg2, byte 1  Desired Active Acoustic Controller (AAC) Mode to set
+ *     If AAC Configuration Type is Global,
+ *         0  AAC mode disabled
+ *         1  AAC mode enabled
+ *     If AAC Configuration Type is USTT mode specific
+ *     (multiple bits may be set for this parameter),
+ *         Bit 0 AAC (Balanced)
+ *         Bit 1 AAC (Cool Bottom
+ *         Bit 2 AAC (Quiet)
+ *         Bit 3 AAC (Performance)
+ */
+
+#define DELL_ACC_GET_FIELD	GENMASK(19, 16)
+#define DELL_ACC_SET_FIELD	GENMASK(11, 8)
+#define DELL_THERMAL_SUPPORTED	GENMASK(3, 0)
+
+static struct platform_profile_handler *thermal_handler;
+
+enum thermal_mode_bits {
+	DELL_BALANCED    = BIT(0),
+	DELL_COOL_BOTTOM = BIT(1),
+	DELL_QUIET       = BIT(2),
+	DELL_PERFORMANCE = BIT(3),
+};
+
+static int thermal_get_mode(void)
+{
+	struct calling_interface_buffer buffer;
+	int state;
+	int ret;
+
+	dell_fill_request(&buffer, 0x0, 0, 0, 0);
+	ret = dell_send_request(&buffer, CLASS_INFO, SELECT_THERMAL_MANAGEMENT);
+	if (ret)
+		return ret;
+	state = buffer.output[2];
+	if (state & DELL_BALANCED)
+		return DELL_BALANCED;
+	else if (state & DELL_COOL_BOTTOM)
+		return DELL_COOL_BOTTOM;
+	else if (state & DELL_QUIET)
+		return DELL_QUIET;
+	else if (state & DELL_PERFORMANCE)
+		return DELL_PERFORMANCE;
+	else
+		return -ENXIO;
+}
+
+static int thermal_get_supported_modes(int *supported_bits)
+{
+	struct calling_interface_buffer buffer;
+	int ret;
+
+	dell_fill_request(&buffer, 0x0, 0, 0, 0);
+	ret = dell_send_request(&buffer, CLASS_INFO, SELECT_THERMAL_MANAGEMENT);
+	/* Thermal function not supported */
+	if (ret == -ENXIO) {
+		*supported_bits = 0;
+		return 0;
+	}
+	if (ret)
+		return ret;
+	*supported_bits = FIELD_GET(DELL_THERMAL_SUPPORTED, buffer.output[1]);
+	return 0;
+}
+
+static int thermal_get_acc_mode(int *acc_mode)
+{
+	struct calling_interface_buffer buffer;
+	int ret;
+
+	dell_fill_request(&buffer, 0x0, 0, 0, 0);
+	ret = dell_send_request(&buffer, CLASS_INFO, SELECT_THERMAL_MANAGEMENT);
+	if (ret)
+		return ret;
+	*acc_mode = FIELD_GET(DELL_ACC_GET_FIELD, buffer.output[3]);
+	return 0;
+}
+
+static int thermal_set_mode(enum thermal_mode_bits state)
+{
+	struct calling_interface_buffer buffer;
+	int ret;
+	int acc_mode;
+
+	ret = thermal_get_acc_mode(&acc_mode);
+	if (ret)
+		return ret;
+
+	dell_fill_request(&buffer, 0x1, FIELD_PREP(DELL_ACC_SET_FIELD, acc_mode) | state, 0, 0);
+	return dell_send_request(&buffer, CLASS_INFO, SELECT_THERMAL_MANAGEMENT);
+}
+
+static int thermal_platform_profile_set(struct platform_profile_handler *pprof,
+					enum platform_profile_option profile)
+{
+	switch (profile) {
+	case PLATFORM_PROFILE_BALANCED:
+		return thermal_set_mode(DELL_BALANCED);
+	case PLATFORM_PROFILE_PERFORMANCE:
+		return thermal_set_mode(DELL_PERFORMANCE);
+	case PLATFORM_PROFILE_QUIET:
+		return thermal_set_mode(DELL_QUIET);
+	case PLATFORM_PROFILE_COOL:
+		return thermal_set_mode(DELL_COOL_BOTTOM);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int thermal_platform_profile_get(struct platform_profile_handler *pprof,
+					enum platform_profile_option *profile)
+{
+	int ret;
+
+	ret = thermal_get_mode();
+	if (ret < 0)
+		return ret;
+
+	switch (ret) {
+	case DELL_BALANCED:
+		*profile = PLATFORM_PROFILE_BALANCED;
+		break;
+	case DELL_PERFORMANCE:
+		*profile = PLATFORM_PROFILE_PERFORMANCE;
+		break;
+	case DELL_COOL_BOTTOM:
+		*profile = PLATFORM_PROFILE_COOL;
+		break;
+	case DELL_QUIET:
+		*profile = PLATFORM_PROFILE_QUIET;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int thermal_init(void)
+{
+	int ret;
+	int supported_modes;
+
+	/* If thermal commands are not supported, exit without error */
+	if (!dell_smbios_class_is_supported(CLASS_INFO))
+		return 0;
+
+	/* If thermal modes are not supported, exit without error */
+	ret = thermal_get_supported_modes(&supported_modes);
+	if (ret < 0)
+		return ret;
+	if (!supported_modes)
+		return 0;
+
+	thermal_handler = kzalloc(sizeof(*thermal_handler), GFP_KERNEL);
+	if (!thermal_handler)
+		return -ENOMEM;
+	thermal_handler->profile_get = thermal_platform_profile_get;
+	thermal_handler->profile_set = thermal_platform_profile_set;
+
+	if (supported_modes & DELL_QUIET)
+		set_bit(PLATFORM_PROFILE_QUIET, thermal_handler->choices);
+	if (supported_modes & DELL_COOL_BOTTOM)
+		set_bit(PLATFORM_PROFILE_COOL, thermal_handler->choices);
+	if (supported_modes & DELL_BALANCED)
+		set_bit(PLATFORM_PROFILE_BALANCED, thermal_handler->choices);
+	if (supported_modes & DELL_PERFORMANCE)
+		set_bit(PLATFORM_PROFILE_PERFORMANCE, thermal_handler->choices);
+
+	/* Clean up if failed */
+	ret = platform_profile_register(thermal_handler);
+	if (ret)
+		kfree(thermal_handler);
+
+	return ret;
+}
+
+static void thermal_cleanup(void)
+{
+	if (thermal_handler) {
+		platform_profile_remove();
+		kfree(thermal_handler);
+	}
+}
+
+static int __init dell_init(void)
+{
+	int ret;
+
+	if (!dmi_check_system(dell_device_table))
+		return -ENODEV;
+
+	/* Do not fail module if thermal modes not supported, just skip */
+	ret = thermal_init();
+	if (ret)
+		goto fail_thermal;
+
+	return 0;
+
+fail_thermal:
+	thermal_cleanup();
+	return ret;
+}
+
+static void __exit dell_exit(void)
+{
+	thermal_cleanup();
+}
+
+module_init(dell_init);
+module_exit(dell_exit);
+
+MODULE_AUTHOR("Lyndon Sanche <lsanche@lyndeno.ca>");
+MODULE_DESCRIPTION("Dell PC driver");
+MODULE_LICENSE("GPL");

drivers/platform/x86/dell/dell-smbios-base.c

@@ -71,6 +71,7 @@ static struct smbios_call call_blacklist[] = {
 	/* handled by kernel: dell-laptop */
 	{0x0000, CLASS_INFO, SELECT_RFKILL},
 	{0x0000, CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT},
+	{0x0000, CLASS_INFO, SELECT_THERMAL_MANAGEMENT},
 };
 
 struct token_range {

drivers/platform/x86/dell/dell-smbios.h

@@ -19,6 +19,7 @@
 /* Classes and selects used only in kernel drivers */
 #define CLASS_KBD_BACKLIGHT 4
 #define SELECT_KBD_BACKLIGHT 11
+#define SELECT_THERMAL_MANAGEMENT 19
 
 /* Tokens used in kernel drivers, any of these
  * should be filtered from userspace access