linux/drivers/mfd/intel-lpss-acpi.c
Mika Westerberg 0343b2f4e4 mfd: intel-lpss: Pass I2C configuration via properties on BXT
I2C host controller need to be configured properly in order to meet I2C
timings specified in the I2C protocol specification. Some Intel Broxton
based machines do not have this information in the ACPI namespace (or the
boot firmware does not support ACPI at all) so we use build-in device
properties instead.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2016-03-16 08:50:42 +00:00

128 lines
3.3 KiB
C

/*
* Intel LPSS ACPI support.
*
* Copyright (C) 2015, Intel Corporation
*
* Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
* Mika Westerberg <mika.westerberg@linux.intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/acpi.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include "intel-lpss.h"
static const struct intel_lpss_platform_info spt_info = {
.clk_rate = 120000000,
};
static struct property_entry spt_i2c_properties[] = {
PROPERTY_ENTRY_U32("i2c-sda-hold-time-ns", 230),
{ },
};
static struct property_set spt_i2c_pset = {
.properties = spt_i2c_properties,
};
static const struct intel_lpss_platform_info spt_i2c_info = {
.clk_rate = 120000000,
.pset = &spt_i2c_pset,
};
static const struct intel_lpss_platform_info bxt_info = {
.clk_rate = 100000000,
};
static struct property_entry bxt_i2c_properties[] = {
PROPERTY_ENTRY_U32("i2c-sda-hold-time-ns", 42),
PROPERTY_ENTRY_U32("i2c-sda-falling-time-ns", 171),
PROPERTY_ENTRY_U32("i2c-scl-falling-time-ns", 208),
{ },
};
static struct property_set bxt_i2c_pset = {
.properties = bxt_i2c_properties,
};
static const struct intel_lpss_platform_info bxt_i2c_info = {
.clk_rate = 133000000,
.pset = &bxt_i2c_pset,
};
static const struct acpi_device_id intel_lpss_acpi_ids[] = {
/* SPT */
{ "INT3446", (kernel_ulong_t)&spt_i2c_info },
{ "INT3447", (kernel_ulong_t)&spt_i2c_info },
/* BXT */
{ "80860AAC", (kernel_ulong_t)&bxt_i2c_info },
{ "80860ABC", (kernel_ulong_t)&bxt_info },
{ "80860AC2", (kernel_ulong_t)&bxt_info },
/* APL */
{ "80865AAC", (kernel_ulong_t)&bxt_i2c_info },
{ "80865ABC", (kernel_ulong_t)&bxt_info },
{ "80865AC2", (kernel_ulong_t)&bxt_info },
{ }
};
MODULE_DEVICE_TABLE(acpi, intel_lpss_acpi_ids);
static int intel_lpss_acpi_probe(struct platform_device *pdev)
{
struct intel_lpss_platform_info *info;
const struct acpi_device_id *id;
id = acpi_match_device(intel_lpss_acpi_ids, &pdev->dev);
if (!id)
return -ENODEV;
info = devm_kmemdup(&pdev->dev, (void *)id->driver_data, sizeof(*info),
GFP_KERNEL);
if (!info)
return -ENOMEM;
info->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
info->irq = platform_get_irq(pdev, 0);
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
return intel_lpss_probe(&pdev->dev, info);
}
static int intel_lpss_acpi_remove(struct platform_device *pdev)
{
intel_lpss_remove(&pdev->dev);
pm_runtime_disable(&pdev->dev);
return 0;
}
static INTEL_LPSS_PM_OPS(intel_lpss_acpi_pm_ops);
static struct platform_driver intel_lpss_acpi_driver = {
.probe = intel_lpss_acpi_probe,
.remove = intel_lpss_acpi_remove,
.driver = {
.name = "intel-lpss",
.acpi_match_table = intel_lpss_acpi_ids,
.pm = &intel_lpss_acpi_pm_ops,
},
};
module_platform_driver(intel_lpss_acpi_driver);
MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
MODULE_DESCRIPTION("Intel LPSS ACPI driver");
MODULE_LICENSE("GPL v2");