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// SPDX-License-Identifier: GPL-2.0-only /* * Intel Low Power Subsystem PWM controller driver * * Copyright (C) 2014, Intel Corporation * * Derived from the original pwm-lpss.c */ #include <linux/kernel.h> #include <linux/mod_devicetable.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/property.h> #include "pwm-lpss.h" static int pwm_lpss_probe_platform(struct platform_device *pdev) { const struct pwm_lpss_boardinfo *info; struct pwm_chip *chip; void __iomem *base; info = device_get_match_data(&pdev->dev); if (!info) return -ENODEV; base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(base)) return PTR_ERR(base); chip = devm_pwm_lpss_probe(&pdev->dev, base, info); if (IS_ERR(chip)) return PTR_ERR(chip); /* * 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 * * Leaving the controller runtime-suspended (skipping runtime-resume + * normal-suspend) during suspend is fine. */ if (info->other_devices_aml_touches_pwm_regs) dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE| DPM_FLAG_SMART_SUSPEND); pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); return 0; } static void pwm_lpss_remove_platform(struct platform_device *pdev) { pm_runtime_disable(&pdev->dev); } static const struct acpi_device_id pwm_lpss_acpi_match[] = { { "80860F09", (unsigned long)&pwm_lpss_byt_info }, { "80862288", (unsigned long)&pwm_lpss_bsw_info }, { "80862289", (unsigned long)&pwm_lpss_bsw_info }, { "80865AC8", (unsigned long)&pwm_lpss_bxt_info }, { }, }; MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match); static struct platform_driver pwm_lpss_driver_platform = { .driver = { .name = "pwm-lpss", .acpi_match_table = pwm_lpss_acpi_match, }, .probe = pwm_lpss_probe_platform, .remove_new = pwm_lpss_remove_platform, }; module_platform_driver(pwm_lpss_driver_platform); MODULE_DESCRIPTION("PWM platform driver for Intel LPSS"); MODULE_LICENSE("GPL v2"); MODULE_IMPORT_NS(PWM_LPSS); MODULE_ALIAS("platform:pwm-lpss"); |