1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Intel Low Power Subsystem PWM controller driver 4 * 5 * Copyright (C) 2014, Intel Corporation 6 * 7 * Derived from the original pwm-lpss.c 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/mod_devicetable.h> 12 #include <linux/module.h> 13 #include <linux/platform_device.h> 14 #include <linux/pm_runtime.h> 15 #include <linux/property.h> 16 17 #include "pwm-lpss.h" 18 19 20 static int pwm_lpss_probe_platform(struct platform_device *pdev) 21 { 22 const struct pwm_lpss_boardinfo *info; 23 struct pwm_lpss_chip *lpwm; 24 void __iomem *base; 25 26 info = device_get_match_data(&pdev->dev); 27 if (!info) 28 return -ENODEV; 29 30 base = devm_platform_ioremap_resource(pdev, 0); 31 if (IS_ERR(base)) 32 return PTR_ERR(base); 33 34 lpwm = pwm_lpss_probe(&pdev->dev, base, info); 35 if (IS_ERR(lpwm)) 36 return PTR_ERR(lpwm); 37 38 platform_set_drvdata(pdev, lpwm); 39 40 /* 41 * On Cherry Trail devices the GFX0._PS0 AML checks if the controller 42 * is on and if it is not on it turns it on and restores what it 43 * believes is the correct state to the PWM controller. 44 * Because of this we must disallow direct-complete, which keeps the 45 * controller (runtime)suspended on resume, to avoid 2 issues: 46 * 1. The controller getting turned on without the linux-pm code 47 * knowing about this. On devices where the controller is unused 48 * this causes it to stay on during the next suspend causing high 49 * battery drain (because S0i3 is not reached) 50 * 2. The state restoring code unexpectedly messing with the controller 51 * 52 * Leaving the controller runtime-suspended (skipping runtime-resume + 53 * normal-suspend) during suspend is fine. 54 */ 55 if (info->other_devices_aml_touches_pwm_regs) 56 dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE| 57 DPM_FLAG_SMART_SUSPEND); 58 59 pm_runtime_set_active(&pdev->dev); 60 pm_runtime_enable(&pdev->dev); 61 62 return 0; 63 } 64 65 static int pwm_lpss_remove_platform(struct platform_device *pdev) 66 { 67 pm_runtime_disable(&pdev->dev); 68 return 0; 69 } 70 71 static const struct acpi_device_id pwm_lpss_acpi_match[] = { 72 { "80860F09", (unsigned long)&pwm_lpss_byt_info }, 73 { "80862288", (unsigned long)&pwm_lpss_bsw_info }, 74 { "80862289", (unsigned long)&pwm_lpss_bsw_info }, 75 { "80865AC8", (unsigned long)&pwm_lpss_bxt_info }, 76 { }, 77 }; 78 MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match); 79 80 static struct platform_driver pwm_lpss_driver_platform = { 81 .driver = { 82 .name = "pwm-lpss", 83 .acpi_match_table = pwm_lpss_acpi_match, 84 }, 85 .probe = pwm_lpss_probe_platform, 86 .remove = pwm_lpss_remove_platform, 87 }; 88 module_platform_driver(pwm_lpss_driver_platform); 89 90 MODULE_DESCRIPTION("PWM platform driver for Intel LPSS"); 91 MODULE_LICENSE("GPL v2"); 92 MODULE_IMPORT_NS(PWM_LPSS); 93 MODULE_ALIAS("platform:pwm-lpss"); 94