diff options
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/acpi-dma.c | 172 | ||||
| -rw-r--r-- | drivers/dma/tegra20-apb-dma.c | 5 |
2 files changed, 169 insertions, 8 deletions
diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c index ba6fc62e9651..5a18f82f732a 100644 --- a/drivers/dma/acpi-dma.c +++ b/drivers/dma/acpi-dma.c @@ -4,7 +4,8 @@ * Based on of-dma.c * * Copyright (C) 2013, Intel Corporation - * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com> + * 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 @@ -16,6 +17,7 @@ #include <linux/list.h> #include <linux/mutex.h> #include <linux/slab.h> +#include <linux/ioport.h> #include <linux/acpi.h> #include <linux/acpi_dma.h> @@ -23,6 +25,117 @@ static LIST_HEAD(acpi_dma_list); static DEFINE_MUTEX(acpi_dma_lock); /** + * acpi_dma_parse_resource_group - match device and parse resource group + * @grp: CSRT resource group + * @adev: ACPI device to match with + * @adma: struct acpi_dma of the given DMA controller + * + * Returns 1 on success, 0 when no information is available, or appropriate + * errno value on error. + * + * In order to match a device from DSDT table to the corresponding CSRT device + * we use MMIO address and IRQ. + */ +static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp, + struct acpi_device *adev, struct acpi_dma *adma) +{ + const struct acpi_csrt_shared_info *si; + struct list_head resource_list; + struct resource_list_entry *rentry; + resource_size_t mem = 0, irq = 0; + u32 vendor_id; + int ret; + + if (grp->shared_info_length != sizeof(struct acpi_csrt_shared_info)) + return -ENODEV; + + INIT_LIST_HEAD(&resource_list); + ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL); + if (ret <= 0) + return 0; + + list_for_each_entry(rentry, &resource_list, node) { + if (resource_type(&rentry->res) == IORESOURCE_MEM) + mem = rentry->res.start; + else if (resource_type(&rentry->res) == IORESOURCE_IRQ) + irq = rentry->res.start; + } + + acpi_dev_free_resource_list(&resource_list); + + /* Consider initial zero values as resource not found */ + if (mem == 0 && irq == 0) + return 0; + + si = (const struct acpi_csrt_shared_info *)&grp[1]; + + /* Match device by MMIO and IRQ */ + if (si->mmio_base_low != mem || si->gsi_interrupt != irq) + return 0; + + vendor_id = le32_to_cpu(grp->vendor_id); + dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n", + (char *)&vendor_id, grp->device_id, grp->revision); + + /* Check if the request line range is available */ + if (si->base_request_line == 0 && si->num_handshake_signals == 0) + return 0; + + adma->base_request_line = si->base_request_line; + adma->end_request_line = si->base_request_line + + si->num_handshake_signals - 1; + + dev_dbg(&adev->dev, "request line base: 0x%04x end: 0x%04x\n", + adma->base_request_line, adma->end_request_line); + + return 1; +} + +/** + * acpi_dma_parse_csrt - parse CSRT to exctract additional DMA resources + * @adev: ACPI device to match with + * @adma: struct acpi_dma of the given DMA controller + * + * 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 are using this table to get the request line range of the specific DMA + * controller to be used later. + * + */ +static void acpi_dma_parse_csrt(struct acpi_device *adev, struct acpi_dma *adma) +{ + 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) + dev_warn(&adev->dev, "failed to get the CSRT table\n"); + return; + } + + grp = (struct acpi_csrt_group *)(csrt + 1); + end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length); + + while (grp < end) { + ret = acpi_dma_parse_resource_group(grp, adev, adma); + if (ret < 0) { + dev_warn(&adev->dev, + "error in parsing resource group\n"); + return; + } + + grp = (struct acpi_csrt_group *)((void *)grp + grp->length); + } +} + +/** * acpi_dma_controller_register - Register a DMA controller to ACPI DMA helpers * @dev: struct device of DMA controller * @acpi_dma_xlate: translation function which converts a dma specifier @@ -61,6 +174,8 @@ int acpi_dma_controller_register(struct device *dev, adma->acpi_dma_xlate = acpi_dma_xlate; adma->data = data; + acpi_dma_parse_csrt(adev, adma); + /* Now queue acpi_dma controller structure in list */ mutex_lock(&acpi_dma_lock); list_add_tail(&adma->dma_controllers, &acpi_dma_list); @@ -149,6 +264,45 @@ void devm_acpi_dma_controller_free(struct device *dev) } EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free); +/** + * acpi_dma_update_dma_spec - prepare dma specifier to pass to translation function + * @adma: struct acpi_dma of DMA controller + * @dma_spec: dma specifier to update + * + * Returns 0, if no information is avaiable, -1 on mismatch, and 1 otherwise. + * + * Accordingly to ACPI 5.0 Specification Table 6-170 "Fixed DMA Resource + * Descriptor": + * DMA Request Line bits is a platform-relative number uniquely + * identifying the request line assigned. Request line-to-Controller + * mapping is done in a controller-specific OS driver. + * That's why we can safely adjust slave_id when the appropriate controller is + * found. + */ +static int acpi_dma_update_dma_spec(struct acpi_dma *adma, + struct acpi_dma_spec *dma_spec) +{ + /* Set link to the DMA controller device */ + dma_spec->dev = adma->dev; + + /* Check if the request line range is available */ + if (adma->base_request_line == 0 && adma->end_request_line == 0) + return 0; + + /* Check if slave_id falls to the range */ + if (dma_spec->slave_id < adma->base_request_line || + dma_spec->slave_id > adma->end_request_line) + return -1; + + /* + * Here we adjust slave_id. It should be a relative number to the base + * request line. + */ + dma_spec->slave_id -= adma->base_request_line; + + return 1; +} + struct acpi_dma_parser_data { struct acpi_dma_spec dma_spec; size_t index; @@ -193,6 +347,7 @@ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, struct acpi_device *adev; struct acpi_dma *adma; struct dma_chan *chan = NULL; + int found; /* Check if the device was enumerated by ACPI */ if (!dev || !ACPI_HANDLE(dev)) @@ -219,9 +374,20 @@ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, mutex_lock(&acpi_dma_lock); list_for_each_entry(adma, &acpi_dma_list, dma_controllers) { - dma_spec->dev = adma->dev; + /* + * We are not going to call translation function if slave_id + * doesn't fall to the request range. + */ + found = acpi_dma_update_dma_spec(adma, dma_spec); + if (found < 0) + continue; chan = adma->acpi_dma_xlate(dma_spec, adma); - if (chan) + /* + * Try to get a channel only from the DMA controller that + * matches the slave_id. See acpi_dma_update_dma_spec() + * description for the details. + */ + if (found > 0 || chan) break; } diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c index ce193409ebd3..33f59ecd256e 100644 --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -1273,11 +1273,6 @@ static int tegra_dma_probe(struct platform_device *pdev) platform_set_drvdata(pdev, tdma); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!res) { - dev_err(&pdev->dev, "No mem resource for DMA\n"); - return -EINVAL; - } - tdma->base_addr = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(tdma->base_addr)) return PTR_ERR(tdma->base_addr); |