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From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
Date: Fri, 26 Apr 2024 09:57:06 +0300 (EEST)
To: Lyndon Sanche <lsanche@lyndeno.ca>
cc: Matthew Garrett <mjg59@srcf.ucam.org>, 
    =?ISO-8859-15?Q?Pali_Roh=E1r?= <pali@kernel.org>, 
    Hans de Goede <hdegoede@redhat.com>, platform-driver-x86@vger.kernel.org, 
    LKML <linux-kernel@vger.kernel.org>, Dell.Client.Kernel@dell.com
Subject: Re: [PATCH] platform/x86: dell-laptop: Implement platform_profile
In-Reply-To: <20240425172758.67831-1-lsanche@lyndeno.ca>
Message-ID: <3e99b429-835e-07e1-358f-f67128cb2e87@linux.intel.com>
References: <20240425172758.67831-1-lsanche@lyndeno.ca>
Precedence: bulk
MIME-Version: 1.0
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On Thu, 25 Apr 2024, Lyndon Sanche wrote:

> 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.

These are too short lines, wrap at 72 (or 75) characters.

> Signed-off-by: Lyndon Sanche <lsanche@lyndeno.ca>
> ---
>  drivers/platform/x86/dell/dell-laptop.c | 220 ++++++++++++++++++++++++
>  drivers/platform/x86/dell/dell-smbios.h |   1 +
>  2 files changed, 221 insertions(+)
> 
> diff --git a/drivers/platform/x86/dell/dell-laptop.c b/drivers/platform/x86/dell/dell-laptop.c
> index 42f7de2b4522..7f9c4e0e5ef5 100644
> --- a/drivers/platform/x86/dell/dell-laptop.c
> +++ b/drivers/platform/x86/dell/dell-laptop.c
> @@ -27,6 +27,7 @@
>  #include <linux/i8042.h>
>  #include <linux/debugfs.h>
>  #include <linux/seq_file.h>
> +#include <linux/platform_profile.h>
>  #include <acpi/video.h>
>  #include "dell-rbtn.h"
>  #include "dell-smbios.h"
> @@ -95,10 +96,18 @@ static struct backlight_device *dell_backlight_device;
>  static struct rfkill *wifi_rfkill;
>  static struct rfkill *bluetooth_rfkill;
>  static struct rfkill *wwan_rfkill;
> +static struct platform_profile_handler *thermal_handler;
>  static bool force_rfkill;
>  static bool micmute_led_registered;
>  static bool mute_led_registered;
>  
> +enum thermal_mode_bits {
> +	DELL_BALANCED = 0,
> +	DELL_COOL_BOTTOM = 1,
> +	DELL_QUIET = 2,
> +	DELL_PERFORMANCE = 3,
> +};

It would seem more more natural to define these with BIT(x) as that's how 
they're used in the code below?

>  module_param(force_rfkill, bool, 0444);
>  MODULE_PARM_DESC(force_rfkill, "enable rfkill on non whitelisted models");
>  
> @@ -2199,6 +2208,211 @@ static int mute_led_set(struct led_classdev *led_cdev,
>  	return 0;
>  }
>  
> +// 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)

Please use

/*
 *
 */

format for multiline comments.

Don't exceed 80 characters with comments.

> +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) & 1)
> +		return DELL_BALANCED;
> +	else if ((state >> DELL_COOL_BOTTOM) & 1)
> +		return DELL_COOL_BOTTOM;
> +	else if ((state >> DELL_QUIET) & 1)
> +		return DELL_QUIET;
> +	else if ((state >> DELL_PERFORMANCE) & 1)
> +		return DELL_PERFORMANCE;

When you convert defines to use BIT(), these become simpler.

> +	else
> +		return 0;
> +}
> +
> +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);
> +	if (ret)
> +		return ret;
> +	*supported_bits = buffer.output[1] & 0xF;

Add named define + use FIELD_GET() + add #include <linux/bitfield.h> if 
not there already.

> +	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 = ((buffer.output[3] >> 8) & 0xFF);

Use named define + FIELD_GET()

> +	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, (acc_mode << 8) | BIT(state), 0, 0);

Named define + FIELD_PREP(XX, acc_mode)

After converting the enum values to use BIT(), you can remove BIT() from 
here.

> +	ret = dell_send_request(&buffer, CLASS_INFO, SELECT_THERMAL_MANAGEMENT);
> +	return ret;
> +}
> +
> +static int thermal_platform_profile_set(struct platform_profile_handler *pprof,
> +					enum platform_profile_option profile)
> +{
> +	int ret;
> +
> +	switch (profile) {
> +	case PLATFORM_PROFILE_BALANCED:
> +		ret = thermal_set_mode(DELL_BALANCED);
> +		break;
> +	case PLATFORM_PROFILE_PERFORMANCE:
> +		ret = thermal_set_mode(DELL_PERFORMANCE);
> +		break;
> +	case PLATFORM_PROFILE_QUIET:
> +		ret = thermal_set_mode(DELL_QUIET);
> +		break;
> +	case PLATFORM_PROFILE_COOL:
> +		ret = thermal_set_mode(DELL_COOL_BOTTOM);
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return ret;
> +}
> +
> +static int thermal_platform_profile_get(struct platform_profile_handler *pprof,
> +					enum platform_profile_option *profile)
> +{
> +	switch (thermal_get_mode()) {
> +	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;
> +}
> +
> +int thermal_init(void)
> +{
> +	int ret;
> +	int supported_modes;
> +
> +	ret = thermal_get_supported_modes(&supported_modes);
> +
> +	if (ret != 0 || supported_modes == 0)

Don't leave empty lines between call and its error handling.

> +		return -ENXIO;
> +
> +	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) & 1)
> +		set_bit(PLATFORM_PROFILE_QUIET, thermal_handler->choices);
> +	if ((supported_modes >> DELL_COOL_BOTTOM) & 1)
> +		set_bit(PLATFORM_PROFILE_COOL, thermal_handler->choices);
> +	if ((supported_modes >> DELL_BALANCED) & 1)
> +		set_bit(PLATFORM_PROFILE_BALANCED, thermal_handler->choices);
> +	if ((supported_modes >> DELL_PERFORMANCE) & 1)

These too will get simpler when the values are using BIT().

> +		set_bit(PLATFORM_PROFILE_PERFORMANCE, thermal_handler->choices);
> +
> +	platform_profile_register(thermal_handler);
> +
> +	return 0;
> +}
> +
> +void thermal_cleanup(void)
> +{
> +	platform_profile_remove();

This should be called if thermal_init() failed, sysfs_remove_group() will 
be called for a group that was never created and I don't think that's 
okay.

> +	kfree(thermal_handler);
> +}
> +
>  static struct led_classdev mute_led_cdev = {
>  	.name = "platform::mute",
>  	.max_brightness = 1,
> @@ -2266,6 +2480,11 @@ static int __init dell_init(void)
>  		mute_led_registered = true;
>  	}
>  
> +	// Do not fail module if thermal modes not supported,
> +	// just skip

Fits to one line.

> +	if (thermal_init() != 0)
> +		pr_warn("Unable to setup platform_profile, skipping");
> +
>  	if (acpi_video_get_backlight_type() != acpi_backlight_vendor)
>  		return 0;
>  
> @@ -2344,6 +2563,7 @@ static void __exit dell_exit(void)
>  		platform_device_unregister(platform_device);
>  		platform_driver_unregister(&platform_driver);
>  	}
> +	thermal_cleanup();
>  }
>  
>  /* dell-rbtn.c driver export functions which will not work correctly (and could
> diff --git a/drivers/platform/x86/dell/dell-smbios.h b/drivers/platform/x86/dell/dell-smbios.h
> index eb341bf000c6..585d042f1779 100644
> --- a/drivers/platform/x86/dell/dell-smbios.h
> +++ b/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
> 

-- 
 i.