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path: root/drivers/acpi/csrt.c
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Diffstat (limited to 'drivers/acpi/csrt.c')
-rw-r--r--drivers/acpi/csrt.c159
1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/acpi/csrt.c b/drivers/acpi/csrt.c
new file mode 100644
index 00000000000..5c15a91faf0
--- /dev/null
+++ b/drivers/acpi/csrt.c
@@ -0,0 +1,159 @@
+/*
+ * Support for Core System Resources Table (CSRT)
+ *
+ * Copyright (C) 2013, Intel Corporation
+ * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
+ * Andy Shevchenko <andriy.shevchenko@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.
+ */
+
+#define pr_fmt(fmt) "ACPI: CSRT: " fmt
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sizes.h>
+
+ACPI_MODULE_NAME("CSRT");
+
+static int __init acpi_csrt_parse_shared_info(struct platform_device *pdev,
+ const struct acpi_csrt_group *grp)
+{
+ const struct acpi_csrt_shared_info *si;
+ struct resource res[3];
+ size_t nres;
+ int ret;
+
+ memset(res, 0, sizeof(res));
+ nres = 0;
+
+ si = (const struct acpi_csrt_shared_info *)&grp[1];
+ /*
+ * The peripherals that are listed on CSRT typically support only
+ * 32-bit addresses so we only use the low part of MMIO base for
+ * now.
+ */
+ if (!si->mmio_base_high && si->mmio_base_low) {
+ /*
+ * There is no size of the memory resource in shared_info
+ * so we assume that it is 4k here.
+ */
+ res[nres].start = si->mmio_base_low;
+ res[nres].end = res[0].start + SZ_4K - 1;
+ res[nres++].flags = IORESOURCE_MEM;
+ }
+
+ if (si->gsi_interrupt) {
+ int irq = acpi_register_gsi(NULL, si->gsi_interrupt,
+ si->interrupt_mode,
+ si->interrupt_polarity);
+ res[nres].start = irq;
+ res[nres].end = irq;
+ res[nres++].flags = IORESOURCE_IRQ;
+ }
+
+ if (si->base_request_line || si->num_handshake_signals) {
+ /*
+ * We pass the driver a DMA resource describing the range
+ * of request lines the device supports.
+ */
+ res[nres].start = si->base_request_line;
+ res[nres].end = res[nres].start + si->num_handshake_signals - 1;
+ res[nres++].flags = IORESOURCE_DMA;
+ }
+
+ ret = platform_device_add_resources(pdev, res, nres);
+ if (ret) {
+ if (si->gsi_interrupt)
+ acpi_unregister_gsi(si->gsi_interrupt);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int __init
+acpi_csrt_parse_resource_group(const struct acpi_csrt_group *grp)
+{
+ struct platform_device *pdev;
+ char vendor[5], name[16];
+ int ret, i;
+
+ vendor[0] = grp->vendor_id;
+ vendor[1] = grp->vendor_id >> 8;
+ vendor[2] = grp->vendor_id >> 16;
+ vendor[3] = grp->vendor_id >> 24;
+ vendor[4] = '\0';
+
+ if (grp->shared_info_length != sizeof(struct acpi_csrt_shared_info))
+ return -ENODEV;
+
+ snprintf(name, sizeof(name), "%s%04X", vendor, grp->device_id);
+ pdev = platform_device_alloc(name, PLATFORM_DEVID_AUTO);
+ if (!pdev)
+ return -ENOMEM;
+
+ /* Add resources based on the shared info */
+ ret = acpi_csrt_parse_shared_info(pdev, grp);
+ if (ret)
+ goto fail;
+
+ ret = platform_device_add(pdev);
+ if (ret)
+ goto fail;
+
+ for (i = 0; i < pdev->num_resources; i++)
+ dev_dbg(&pdev->dev, "%pR\n", &pdev->resource[i]);
+
+ return 0;
+
+fail:
+ platform_device_put(pdev);
+ return ret;
+}
+
+/*
+ * CSRT or Core System Resources Table is a proprietary ACPI table
+ * introduced by Microsoft. This table can contain devices that are not in
+ * the system DSDT table. In particular DMA controllers might be described
+ * here.
+ *
+ * We present these devices as normal platform devices that don't have ACPI
+ * IDs or handle. The platform device name will be something like
+ * <VENDOR><DEVID>.<n>.auto for example: INTL9C06.0.auto.
+ */
+void __init acpi_csrt_init(void)
+{
+ struct acpi_csrt_group *grp, *end;
+ struct acpi_table_csrt *csrt;
+ acpi_status status;
+ int ret;
+
+ status = acpi_get_table(ACPI_SIG_CSRT, 0,
+ (struct acpi_table_header **)&csrt);
+ if (ACPI_FAILURE(status)) {
+ if (status != AE_NOT_FOUND)
+ pr_warn("failed to get the CSRT table\n");
+ return;
+ }
+
+ pr_debug("parsing CSRT table for devices\n");
+
+ grp = (struct acpi_csrt_group *)(csrt + 1);
+ end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length);
+
+ while (grp < end) {
+ ret = acpi_csrt_parse_resource_group(grp);
+ if (ret) {
+ pr_warn("error in parsing resource group: %d\n", ret);
+ return;
+ }
+
+ grp = (struct acpi_csrt_group *)((void *)grp + grp->length);
+ }
+}