diff options
Diffstat (limited to 'drivers/pwm/pwm-lpss-platform.c')
-rw-r--r-- | drivers/pwm/pwm-lpss-platform.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-lpss-platform.c b/drivers/pwm/pwm-lpss-platform.c new file mode 100644 index 0000000000..319809aac2 --- /dev/null +++ b/drivers/pwm/pwm-lpss-platform.c @@ -0,0 +1,92 @@ +// 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_lpss_chip *lpwm; + 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); + + lpwm = devm_pwm_lpss_probe(&pdev->dev, base, info); + if (IS_ERR(lpwm)) + return PTR_ERR(lpwm); + + platform_set_drvdata(pdev, lpwm); + + /* + * 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"); |