diff options
Diffstat (limited to 'drivers/acpi/csrt.c')
| -rw-r--r-- | drivers/acpi/csrt.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/acpi/csrt.c b/drivers/acpi/csrt.c new file mode 100644 index 0000000..5c15a91 --- /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); + } +} |
