160 lines
4.1 KiB
C
160 lines
4.1 KiB
C
/*
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* Support for Core System Resources Table (CSRT)
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*
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* Copyright (C) 2013, Intel Corporation
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* Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
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* Andy Shevchenko <andriy.shevchenko@linux.intel.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#define pr_fmt(fmt) "ACPI: CSRT: " fmt
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#include <linux/acpi.h>
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/sizes.h>
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ACPI_MODULE_NAME("CSRT");
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static int __init acpi_csrt_parse_shared_info(struct platform_device *pdev,
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const struct acpi_csrt_group *grp)
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{
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const struct acpi_csrt_shared_info *si;
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struct resource res[3];
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size_t nres;
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int ret;
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memset(res, 0, sizeof(res));
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nres = 0;
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si = (const struct acpi_csrt_shared_info *)&grp[1];
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/*
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* The peripherals that are listed on CSRT typically support only
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* 32-bit addresses so we only use the low part of MMIO base for
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* now.
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*/
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if (!si->mmio_base_high && si->mmio_base_low) {
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/*
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* There is no size of the memory resource in shared_info
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* so we assume that it is 4k here.
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*/
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res[nres].start = si->mmio_base_low;
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res[nres].end = res[0].start + SZ_4K - 1;
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res[nres++].flags = IORESOURCE_MEM;
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}
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if (si->gsi_interrupt) {
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int irq = acpi_register_gsi(NULL, si->gsi_interrupt,
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si->interrupt_mode,
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si->interrupt_polarity);
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res[nres].start = irq;
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res[nres].end = irq;
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res[nres++].flags = IORESOURCE_IRQ;
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}
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if (si->base_request_line || si->num_handshake_signals) {
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/*
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* We pass the driver a DMA resource describing the range
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* of request lines the device supports.
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*/
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res[nres].start = si->base_request_line;
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res[nres].end = res[nres].start + si->num_handshake_signals - 1;
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res[nres++].flags = IORESOURCE_DMA;
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}
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ret = platform_device_add_resources(pdev, res, nres);
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if (ret) {
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if (si->gsi_interrupt)
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acpi_unregister_gsi(si->gsi_interrupt);
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return ret;
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}
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return 0;
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}
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static int __init
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acpi_csrt_parse_resource_group(const struct acpi_csrt_group *grp)
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{
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struct platform_device *pdev;
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char vendor[5], name[16];
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int ret, i;
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vendor[0] = grp->vendor_id;
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vendor[1] = grp->vendor_id >> 8;
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vendor[2] = grp->vendor_id >> 16;
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vendor[3] = grp->vendor_id >> 24;
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vendor[4] = '\0';
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if (grp->shared_info_length != sizeof(struct acpi_csrt_shared_info))
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return -ENODEV;
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snprintf(name, sizeof(name), "%s%04X", vendor, grp->device_id);
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pdev = platform_device_alloc(name, PLATFORM_DEVID_AUTO);
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if (!pdev)
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return -ENOMEM;
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/* Add resources based on the shared info */
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ret = acpi_csrt_parse_shared_info(pdev, grp);
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if (ret)
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goto fail;
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ret = platform_device_add(pdev);
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if (ret)
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goto fail;
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for (i = 0; i < pdev->num_resources; i++)
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dev_dbg(&pdev->dev, "%pR\n", &pdev->resource[i]);
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return 0;
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fail:
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platform_device_put(pdev);
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return ret;
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}
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/*
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* CSRT or Core System Resources Table is a proprietary ACPI table
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* introduced by Microsoft. This table can contain devices that are not in
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* the system DSDT table. In particular DMA controllers might be described
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* here.
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*
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* We present these devices as normal platform devices that don't have ACPI
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* IDs or handle. The platform device name will be something like
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* <VENDOR><DEVID>.<n>.auto for example: INTL9C06.0.auto.
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*/
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void __init acpi_csrt_init(void)
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{
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struct acpi_csrt_group *grp, *end;
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struct acpi_table_csrt *csrt;
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acpi_status status;
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int ret;
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status = acpi_get_table(ACPI_SIG_CSRT, 0,
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(struct acpi_table_header **)&csrt);
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if (ACPI_FAILURE(status)) {
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if (status != AE_NOT_FOUND)
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pr_warn("failed to get the CSRT table\n");
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return;
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}
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pr_debug("parsing CSRT table for devices\n");
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grp = (struct acpi_csrt_group *)(csrt + 1);
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end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length);
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while (grp < end) {
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ret = acpi_csrt_parse_resource_group(grp);
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if (ret) {
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pr_warn("error in parsing resource group: %d\n", ret);
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return;
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}
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grp = (struct acpi_csrt_group *)((void *)grp + grp->length);
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}
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}
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