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path: root/drivers/pwm/pwm-lpss-platform.c
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2021-06-28pwm: lpss: Simplify using devm_pwmchip_add()Uwe Kleine-König1-3/+1
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-12-17pwm: lpss: Set DPM_FLAG_SMART_SUSPEND on Cherry Trail devicesHans de Goede1-1/+5
As the comment above the code setting the DPM_FLAG_NO_DIRECT_COMPLETE flag explains: /* * On Cherry Trail devices the GFX0._PS0 AML checks if the controller * is on and if it is not on it turns it on and restores what it * believes is the correct state to the PWM controller. * Because of this we must disallow direct-complete, which keeps the * controller (runtime)suspended, on resume to avoid 2 issues: * 1. The controller getting turned on without the linux-pm code * knowing about this. On devices where the controller is unused * this causes it to stay on during the next suspend causing high * battery drain (because S0i3 is not reached) * 2. The state restoring code unexpectedly messing with the controller */ The pm-core must not skip resume to avoid the GFX0._PS0 AML code messing with the PWM controller behind our back. But leaving the controller runtime-suspended (skipping runtime-resume + normal-suspend) during suspend is fine. Set the DPM_FLAG_SMART_SUSPEND flag to allow this. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-12-17pwm: lpss: Use DPM_FLAG_NO_DIRECT_COMPLETE instead of declaring a prepare ↵Hans de Goede1-20/+15
handler ACPI LPSS devices use direct-complete style suspend/resume handling by default. We set the DPM_FLAG_SMART_PREPARE and define a prepare handler to disable this on Cherry Trail devices. Clean this up a bit by setting the DPM_FLAG_NO_DIRECT_COMPLETE flag for Cherry Trail devices, instead of defining a prepare handler. While at it also improve the comment explaining why this is necessary. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-06pwm: lpss: Remove suspend/resume handlersHans de Goede1-1/+0
PWM controller drivers should not restore the PWM state on resume. The convention is that PWM consumers do this by calling pwm_apply_state(), so that it can be done at the exact moment when the consumer needs the state to be stored, avoiding e.g. backlight flickering. The only in kernel consumers of the pwm-lpss code, the i915 driver and the pwm-class sysfs interface code both correctly restore the state on resume, so there is no need to do this in the pwm-lpss code. More-over the removed resume handler is buggy, since it blindly restores the ctrl-register contents without setting the update bit, which is necessary to get the controller to actually use/apply the restored base-unit and on-time-div values. Acked-by: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-8-hdegoede@redhat.com
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-16pwm: lpss: Force runtime-resume on suspend on Cherry TrailHans de Goede1-13/+11
On Cherry Trail devices under Windows the PWM controller used for the backlight is considered part of the GPU even though it is part of the LPSS block and thus is an entirely different independent hardware unit. Because of this on Cherry Trail the GPU's (GFX0 ACPI node) _PS3 and _PS0 methods save and restore the PWM controller registers. If userspace blanks the screen before suspending, such as e.g. GNOME does, then the PWM controller will be runtime-suspended when the suspend starts. This causes the GFX0 _PS? methods to save a value of 0xffffffff for the PWM control register and to restore this value on resume. 0xffffffff is not a valid value for the register and writing this causes problems such as e.g. a flickering backlight. This commit adds a prepare method to the dev_pm_ops and makes it return 0 on Cherry Trail devices forcing a runtime-resume before other device's suspend methods run. This fixes the reading and writing back of 0xffffffff. Since we now always runtime-resume the device on suspend, it will be resumed on resume too and we no longer need to check for the GFX0 _PS0 method having resumed it underneath us, so this commit removes the now no longer necessary complete dev_pm_op. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-10-12pwm: lpss: Check PWM powerstate after resume on Cherry Trail devicesHans de Goede1-3/+22
The _PS0 method for the integrated graphics on some Cherry Trail devices (observed on a HP Pavilion X2 10-p0XX) turns on the PWM chip (puts it in D0), causing an inconsistency between the state the pm-core thinks it is in (left runtime suspended as it was before the suspend/resume) and the state it actually is in. Interestingly enough this is done on a device where the pwm controller is not used for the backlight at all, since it uses an eDP panel. On devices where the PWM is used this is not a problem since we will resume it ourselves anyways. This inconsistency causes us to never suspend the pwm controller again, which causes the device to not be able to reach S0ix states when suspended. This commit adds a resume-complete handler, which when we think the device is still run-time suspended checks the actual power-state and if necessary updates the rpm-core's internal state. This fixes the Pavilion X2 10-p0XX not reaching S0ix states when suspended. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-10-12pwm: lpss: Add ACPI HID for second PWM controller on Cherry Trail devicesHans de Goede1-0/+1
The second PWM controller on Cherry Trail devices uses a separate ACPI HID: "80862289", add this so that the driver will properly bind to the second PWM controller. The second PWM controller is usually not used, the main thing gained by this is properly putting the PWM controller in D3 on suspend. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-06-06pwm: lpss: platform: Save/restore the ctrl register over a suspend/resumeHans de Goede1-0/+5
On some devices the contents of the ctrl register get lost over a suspend/resume and the PWM comes back up disabled after the resume. This is seen on some Bay Trail devices with the PWM in ACPI enumerated mode, so it shows up as a platform device instead of a PCI device. If we still think it is enabled and then try to change the duty-cycle after this, we end up with a "PWM_SW_UPDATE was not cleared" error and the PWM is stuck in that state from then on. This commit adds suspend and resume pm callbacks to the pwm-lpss-platform code, which save/restore the ctrl register over a suspend/resume, fixing this. Note that: 1) There is no need to do this over a runtime suspend, since we only runtime suspend when disabled and then we properly set the enable bit and reprogram the timings when we re-enable the PWM. 2) This may be happening on more systems then we realize, but has been covered up sofar by a bug in the acpi-lpss.c code which was save/restoring the regular device registers instead of the lpss private registers due to lpss_device_desc.prv_offset not being set. This is fixed by a later patch in this series. Cc: stable@vger.kernel.org Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-06pwm: lpss: Set enable-bit before waiting for update-bit to go lowHans de Goede1-0/+1
At least on cherrytrail, the update bit will never go low when the enabled bit is not set. This causes the backlight on my cube iwork8 air tablet to never turn on again after being turned off because in the pwm_lpss_apply enable path pwm_lpss_update will fail causing an error exit and the enable-bit to never get set. Any following pwm_lpss_apply calls will fail the pwm_lpss_is_updating check. Since the docs say that the update bit should be set before the enable-bit, split pwm_lpss_update into setting the update-bit and pwm_lpss_wait_for_update, and move the pwm_lpss_wait_for_update call in the enable path to after setting the enable-bit. Fixes: 10d56a4 ("pwm: lpss: Avoid reconfiguring while UPDATE bit...") Cc: Ilkka Koskinen <ilkka.koskinen@intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30pwm: lpss: Do not export board infos for different PWM typesAndy Shevchenko1-0/+21
The PWM LPSS probe drivers just pass a pointer to the exported board info structures to pwm_lpss_probe() based on device PCI or ACPI ID. In order to remove the knowledge of specific devices from library part of the driver and reduce noise in exported namespace just duplicate the board info structures and stop exporting them. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-06pwm: lpss: Add support for runtime PMQipeng Zha1-0/+6
To be able to save some power when PWM is not in use, add support for runtime PM for this driver. This also allows the platform to transition to low power S0ix states when the system is idle. Signed-off-by: Huiquan Zhong <huiquan.zhong@intel.com> Signed-off-by: Qipeng Zha <qipeng.zha@intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-06pwm: lpss: Add more Intel Broxton IDsMika Westerberg1-0/+1
Add more Intel Broxton ACPI and PCI IDs to the driver supported devices list. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-23pwm: lpss: Properly split driver to partsAndy Shevchenko1-0/+68
The driver consists of core, PCI, and platform parts. It would be better to split them into separate files. The platform driver is now called pwm-lpss-platform. Thus, previously set CONFIG_PWM_LPSS=m is not enough to build it. But we are on the safe side since it seems no one from outside Intel is using it for now. While here, move to use macros module_pci_driver() and module_platform_driver(). Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Alan Cox <alan@linux.intel.com> [thierry.reding: change select to depends on PWM_LPSS, cleanup] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>