cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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pwm-lpss-platform.c (3207B)

      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/acpi.h>
     11#include <linux/kernel.h>
     12#include <linux/module.h>
     13#include <linux/platform_device.h>
     14#include <linux/pm_runtime.h>
     15
     16#include "pwm-lpss.h"
     17
     18/* BayTrail */
     19static const struct pwm_lpss_boardinfo pwm_lpss_byt_info = {
     20	.clk_rate = 25000000,
     21	.npwm = 1,
     22	.base_unit_bits = 16,
     23};
     24
     25/* Braswell */
     26static const struct pwm_lpss_boardinfo pwm_lpss_bsw_info = {
     27	.clk_rate = 19200000,
     28	.npwm = 1,
     29	.base_unit_bits = 16,
     30	.other_devices_aml_touches_pwm_regs = true,
     31};
     32
     33/* Broxton */
     34static const struct pwm_lpss_boardinfo pwm_lpss_bxt_info = {
     35	.clk_rate = 19200000,
     36	.npwm = 4,
     37	.base_unit_bits = 22,
     38	.bypass = true,
     39};
     40
     41static int pwm_lpss_probe_platform(struct platform_device *pdev)
     42{
     43	const struct pwm_lpss_boardinfo *info;
     44	const struct acpi_device_id *id;
     45	struct pwm_lpss_chip *lpwm;
     46	struct resource *r;
     47
     48	id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
     49	if (!id)
     50		return -ENODEV;
     51
     52	info = (const struct pwm_lpss_boardinfo *)id->driver_data;
     53	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
     54
     55	lpwm = pwm_lpss_probe(&pdev->dev, r, info);
     56	if (IS_ERR(lpwm))
     57		return PTR_ERR(lpwm);
     58
     59	platform_set_drvdata(pdev, lpwm);
     60
     61	/*
     62	 * On Cherry Trail devices the GFX0._PS0 AML checks if the controller
     63	 * is on and if it is not on it turns it on and restores what it
     64	 * believes is the correct state to the PWM controller.
     65	 * Because of this we must disallow direct-complete, which keeps the
     66	 * controller (runtime)suspended on resume, to avoid 2 issues:
     67	 * 1. The controller getting turned on without the linux-pm code
     68	 *    knowing about this. On devices where the controller is unused
     69	 *    this causes it to stay on during the next suspend causing high
     70	 *    battery drain (because S0i3 is not reached)
     71	 * 2. The state restoring code unexpectedly messing with the controller
     72	 *
     73	 * Leaving the controller runtime-suspended (skipping runtime-resume +
     74	 * normal-suspend) during suspend is fine.
     75	 */
     76	if (info->other_devices_aml_touches_pwm_regs)
     77		dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE|
     78						    DPM_FLAG_SMART_SUSPEND);
     79
     80	pm_runtime_set_active(&pdev->dev);
     81	pm_runtime_enable(&pdev->dev);
     82
     83	return 0;
     84}
     85
     86static int pwm_lpss_remove_platform(struct platform_device *pdev)
     87{
     88	pm_runtime_disable(&pdev->dev);
     89	return 0;
     90}
     91
     92static const struct acpi_device_id pwm_lpss_acpi_match[] = {
     93	{ "80860F09", (unsigned long)&pwm_lpss_byt_info },
     94	{ "80862288", (unsigned long)&pwm_lpss_bsw_info },
     95	{ "80862289", (unsigned long)&pwm_lpss_bsw_info },
     96	{ "80865AC8", (unsigned long)&pwm_lpss_bxt_info },
     97	{ },
     98};
     99MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
    100
    101static struct platform_driver pwm_lpss_driver_platform = {
    102	.driver = {
    103		.name = "pwm-lpss",
    104		.acpi_match_table = pwm_lpss_acpi_match,
    105	},
    106	.probe = pwm_lpss_probe_platform,
    107	.remove = pwm_lpss_remove_platform,
    108};
    109module_platform_driver(pwm_lpss_driver_platform);
    110
    111MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
    112MODULE_LICENSE("GPL v2");
    113MODULE_ALIAS("platform:pwm-lpss");