From b9c90f153d836522621b5504087cf83419886e30 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Mon, 9 Nov 2020 11:57:25 +0100 Subject: pwm: lpss: Use DPM_FLAG_NO_DIRECT_COMPLETE instead of declaring a prepare 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 Signed-off-by: Hans de Goede Signed-off-by: Thierry Reding --- drivers/pwm/pwm-lpss-platform.c | 35 +++++++++++++++-------------------- 1 file changed, 15 insertions(+), 20 deletions(-) (limited to 'drivers/pwm/pwm-lpss-platform.c') diff --git a/drivers/pwm/pwm-lpss-platform.c b/drivers/pwm/pwm-lpss-platform.c index c6502cf7a7af..ac33861edb48 100644 --- a/drivers/pwm/pwm-lpss-platform.c +++ b/drivers/pwm/pwm-lpss-platform.c @@ -58,7 +58,21 @@ static int pwm_lpss_probe_platform(struct platform_device *pdev) platform_set_drvdata(pdev, lpwm); - dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_SMART_PREPARE); + /* + * 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 + */ + if (info->other_devices_aml_touches_pwm_regs) + dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE); + pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); @@ -73,24 +87,6 @@ static int pwm_lpss_remove_platform(struct platform_device *pdev) return pwm_lpss_remove(lpwm); } -static int pwm_lpss_prepare(struct device *dev) -{ - struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev); - - /* - * If other device's AML code touches the PWM regs on suspend/resume - * force runtime-resume the PWM controller to allow this. - */ - if (lpwm->info->other_devices_aml_touches_pwm_regs) - return 0; /* Force runtime-resume */ - - return 1; /* If runtime-suspended leave as is */ -} - -static const struct dev_pm_ops pwm_lpss_platform_pm_ops = { - .prepare = pwm_lpss_prepare, -}; - static const struct acpi_device_id pwm_lpss_acpi_match[] = { { "80860F09", (unsigned long)&pwm_lpss_byt_info }, { "80862288", (unsigned long)&pwm_lpss_bsw_info }, @@ -104,7 +100,6 @@ static struct platform_driver pwm_lpss_driver_platform = { .driver = { .name = "pwm-lpss", .acpi_match_table = pwm_lpss_acpi_match, - .pm = &pwm_lpss_platform_pm_ops, }, .probe = pwm_lpss_probe_platform, .remove = pwm_lpss_remove_platform, -- cgit v1.2.3