LXR linux/drivers/pwm/pwm-lpss-platform.c

   1/*
   2 * Intel Low Power Subsystem PWM controller driver
   3 *
   4 * Copyright (C) 2014, Intel Corporation
   5 *
   6 * Derived from the original pwm-lpss.c
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 */
  12
  13#include <linux/acpi.h>
  14#include <linux/kernel.h>
  15#include <linux/module.h>
  16#include <linux/platform_device.h>
  17#include <linux/pm_runtime.h>
  18
  19#include "pwm-lpss.h"
  20
  21/* BayTrail */
  22static const struct pwm_lpss_boardinfo pwm_lpss_byt_info = {
  23        .clk_rate = 25000000,
  24        .npwm = 1,
  25        .base_unit_bits = 16,
  26};
  27
  28/* Braswell */
  29static const struct pwm_lpss_boardinfo pwm_lpss_bsw_info = {
  30        .clk_rate = 19200000,
  31        .npwm = 1,
  32        .base_unit_bits = 16,
  33        .other_devices_aml_touches_pwm_regs = true,
  34};
  35
  36/* Broxton */
  37static const struct pwm_lpss_boardinfo pwm_lpss_bxt_info = {
  38        .clk_rate = 19200000,
  39        .npwm = 4,
  40        .base_unit_bits = 22,
  41        .bypass = true,
  42};
  43
  44static int pwm_lpss_probe_platform(struct platform_device *pdev)
  45{
  46        const struct pwm_lpss_boardinfo *info;
  47        const struct acpi_device_id *id;
  48        struct pwm_lpss_chip *lpwm;
  49        struct resource *r;
  50
  51        id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
  52        if (!id)
  53                return -ENODEV;
  54
  55        info = (const struct pwm_lpss_boardinfo *)id->driver_data;
  56        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  57
  58        lpwm = pwm_lpss_probe(&pdev->dev, r, info);
  59        if (IS_ERR(lpwm))
  60                return PTR_ERR(lpwm);
  61
  62        platform_set_drvdata(pdev, lpwm);
  63
  64        dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_SMART_PREPARE);
  65        pm_runtime_set_active(&pdev->dev);
  66        pm_runtime_enable(&pdev->dev);
  67
  68        return 0;
  69}
  70
  71static int pwm_lpss_remove_platform(struct platform_device *pdev)
  72{
  73        struct pwm_lpss_chip *lpwm = platform_get_drvdata(pdev);
  74
  75        pm_runtime_disable(&pdev->dev);
  76        return pwm_lpss_remove(lpwm);
  77}
  78
  79static int pwm_lpss_prepare(struct device *dev)
  80{
  81        struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev);
  82
  83        /*
  84         * If other device's AML code touches the PWM regs on suspend/resume
  85         * force runtime-resume the PWM controller to allow this.
  86         */
  87        if (lpwm->info->other_devices_aml_touches_pwm_regs)
  88                return 0; /* Force runtime-resume */
  89
  90        return 1; /* If runtime-suspended leave as is */
  91}
  92
  93static const struct dev_pm_ops pwm_lpss_platform_pm_ops = {
  94        .prepare = pwm_lpss_prepare,
  95        SET_SYSTEM_SLEEP_PM_OPS(pwm_lpss_suspend, pwm_lpss_resume)
  96};
  97
  98static const struct acpi_device_id pwm_lpss_acpi_match[] = {
  99        { "80860F09", (unsigned long)&pwm_lpss_byt_info },
 100        { "80862288", (unsigned long)&pwm_lpss_bsw_info },
 101        { "80862289", (unsigned long)&pwm_lpss_bsw_info },
 102        { "80865AC8", (unsigned long)&pwm_lpss_bxt_info },
 103        { },
 104};
 105MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
 106
 107static struct platform_driver pwm_lpss_driver_platform = {
 108        .driver = {
 109                .name = "pwm-lpss",
 110                .acpi_match_table = pwm_lpss_acpi_match,
 111                .pm = &pwm_lpss_platform_pm_ops,
 112        },
 113        .probe = pwm_lpss_probe_platform,
 114        .remove = pwm_lpss_remove_platform,
 115};
 116module_platform_driver(pwm_lpss_driver_platform);
 117
 118MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
 119MODULE_LICENSE("GPL v2");
 120MODULE_ALIAS("platform:pwm-lpss");
 121