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 */
  22 static 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 */
  29 static 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 */
  37 static 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
  44 static 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
  71 static 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
  79 static 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
  93 static 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
  98 static 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 };
 105 MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
 106
 107 static 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 };
 116 module_platform_driver(pwm_lpss_driver_platform);
 117
 118 MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
 119 MODULE_LICENSE("GPL v2");
 120 MODULE_ALIAS("platform:pwm-lpss");