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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-09 18:46:45 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-09 18:46:45 +0200 |
commit | 1763e735b0a093a6747078b3bd101f079e576ab6 (patch) | |
tree | 75203a3229977d12dc5a5990d1122e7a3d5f30fc /drivers/dma/acpi-dma.c | |
parent | Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/l... (diff) | |
parent | dma: tegra: implement suspend/resume callbacks (diff) | |
download | linux-1763e735b0a093a6747078b3bd101f079e576ab6.tar.xz linux-1763e735b0a093a6747078b3bd101f079e576ab6.zip |
Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma
Pull slave-dmaengine updates from Vinod Koul:
"This time we have dmatest improvements from Andy along with dw_dmac
fixes. He has also done support for acpi for dmanegine.
Also we have bunch of fixes going in DT support for dmanegine for
various folks. Then Haswell and other ioat changes from Dave and
SUDMAC support from Shimoda."
* 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma: (53 commits)
dma: tegra: implement suspend/resume callbacks
dma:of: Use a mutex to protect the of_dma_list
dma: of: Fix of_node reference leak
dmaengine: sirf: move driver init from module_init to subsys_initcall
sudmac: add support for SUDMAC
dma: sh: add Kconfig
at_hdmac: move to generic DMA binding
ioatdma: ioat3_alloc_sed can be static
ioatdma: Adding write back descriptor error status support for ioatdma 3.3
ioatdma: S1200 platforms ioatdma channel 2 and 3 falsely advertise RAID cap
ioatdma: Adding support for 16 src PQ ops and super extended descriptors
ioatdma: Removing hw bug workaround for CB3.x .2 and earlier
dw_dmac: add ACPI support
dmaengine: call acpi_dma_request_slave_channel as well
dma: acpi-dma: introduce ACPI DMA helpers
dma: of: Remove unnecessary list_empty check
DMA: OF: Check properties value before running be32_to_cpup() on it
DMA: of: Constant names
ioatdma: skip silicon bug workaround for pq_align for cb3.3
ioatdma: Removing PQ val disable for cb3.3
...
Diffstat (limited to 'drivers/dma/acpi-dma.c')
-rw-r--r-- | drivers/dma/acpi-dma.c | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c new file mode 100644 index 000000000000..ba6fc62e9651 --- /dev/null +++ b/drivers/dma/acpi-dma.c @@ -0,0 +1,279 @@ +/* + * ACPI helpers for DMA request / controller + * + * Based on of-dma.c + * + * Copyright (C) 2013, Intel Corporation + * Author: 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. + */ + +#include <linux/device.h> +#include <linux/module.h> +#include <linux/list.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/acpi.h> +#include <linux/acpi_dma.h> + +static LIST_HEAD(acpi_dma_list); +static DEFINE_MUTEX(acpi_dma_lock); + +/** + * 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 + * into a dma_chan structure + * @data pointer to controller specific data to be used by + * translation function + * + * Returns 0 on success or appropriate errno value on error. + * + * Allocated memory should be freed with appropriate acpi_dma_controller_free() + * call. + */ +int acpi_dma_controller_register(struct device *dev, + struct dma_chan *(*acpi_dma_xlate) + (struct acpi_dma_spec *, struct acpi_dma *), + void *data) +{ + struct acpi_device *adev; + struct acpi_dma *adma; + + if (!dev || !acpi_dma_xlate) + return -EINVAL; + + /* Check if the device was enumerated by ACPI */ + if (!ACPI_HANDLE(dev)) + return -EINVAL; + + if (acpi_bus_get_device(ACPI_HANDLE(dev), &adev)) + return -EINVAL; + + adma = kzalloc(sizeof(*adma), GFP_KERNEL); + if (!adma) + return -ENOMEM; + + adma->dev = dev; + adma->acpi_dma_xlate = acpi_dma_xlate; + adma->data = data; + + /* Now queue acpi_dma controller structure in list */ + mutex_lock(&acpi_dma_lock); + list_add_tail(&adma->dma_controllers, &acpi_dma_list); + mutex_unlock(&acpi_dma_lock); + + return 0; +} +EXPORT_SYMBOL_GPL(acpi_dma_controller_register); + +/** + * acpi_dma_controller_free - Remove a DMA controller from ACPI DMA helpers list + * @dev: struct device of DMA controller + * + * Memory allocated by acpi_dma_controller_register() is freed here. + */ +int acpi_dma_controller_free(struct device *dev) +{ + struct acpi_dma *adma; + + if (!dev) + return -EINVAL; + + mutex_lock(&acpi_dma_lock); + + list_for_each_entry(adma, &acpi_dma_list, dma_controllers) + if (adma->dev == dev) { + list_del(&adma->dma_controllers); + mutex_unlock(&acpi_dma_lock); + kfree(adma); + return 0; + } + + mutex_unlock(&acpi_dma_lock); + return -ENODEV; +} +EXPORT_SYMBOL_GPL(acpi_dma_controller_free); + +static void devm_acpi_dma_release(struct device *dev, void *res) +{ + acpi_dma_controller_free(dev); +} + +/** + * devm_acpi_dma_controller_register - resource managed acpi_dma_controller_register() + * @dev: device that is registering this DMA controller + * @acpi_dma_xlate: translation function + * @data pointer to controller specific data + * + * Managed acpi_dma_controller_register(). DMA controller registered by this + * function are automatically freed on driver detach. See + * acpi_dma_controller_register() for more information. + */ +int devm_acpi_dma_controller_register(struct device *dev, + struct dma_chan *(*acpi_dma_xlate) + (struct acpi_dma_spec *, struct acpi_dma *), + void *data) +{ + void *res; + int ret; + + res = devres_alloc(devm_acpi_dma_release, 0, GFP_KERNEL); + if (!res) + return -ENOMEM; + + ret = acpi_dma_controller_register(dev, acpi_dma_xlate, data); + if (ret) { + devres_free(res); + return ret; + } + devres_add(dev, res); + return 0; +} +EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_register); + +/** + * devm_acpi_dma_controller_free - resource managed acpi_dma_controller_free() + * + * Unregister a DMA controller registered with + * devm_acpi_dma_controller_register(). Normally this function will not need to + * be called and the resource management code will ensure that the resource is + * freed. + */ +void devm_acpi_dma_controller_free(struct device *dev) +{ + WARN_ON(devres_destroy(dev, devm_acpi_dma_release, NULL, NULL)); +} +EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free); + +struct acpi_dma_parser_data { + struct acpi_dma_spec dma_spec; + size_t index; + size_t n; +}; + +/** + * acpi_dma_parse_fixed_dma - Parse FixedDMA ACPI resources to a DMA specifier + * @res: struct acpi_resource to get FixedDMA resources from + * @data: pointer to a helper struct acpi_dma_parser_data + */ +static int acpi_dma_parse_fixed_dma(struct acpi_resource *res, void *data) +{ + struct acpi_dma_parser_data *pdata = data; + + if (res->type == ACPI_RESOURCE_TYPE_FIXED_DMA) { + struct acpi_resource_fixed_dma *dma = &res->data.fixed_dma; + + if (pdata->n++ == pdata->index) { + pdata->dma_spec.chan_id = dma->channels; + pdata->dma_spec.slave_id = dma->request_lines; + } + } + + /* Tell the ACPI core to skip this resource */ + return 1; +} + +/** + * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel + * @dev: struct device to get DMA request from + * @index: index of FixedDMA descriptor for @dev + * + * Returns pointer to appropriate dma channel on success or NULL on error. + */ +struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, + size_t index) +{ + struct acpi_dma_parser_data pdata; + struct acpi_dma_spec *dma_spec = &pdata.dma_spec; + struct list_head resource_list; + struct acpi_device *adev; + struct acpi_dma *adma; + struct dma_chan *chan = NULL; + + /* Check if the device was enumerated by ACPI */ + if (!dev || !ACPI_HANDLE(dev)) + return NULL; + + if (acpi_bus_get_device(ACPI_HANDLE(dev), &adev)) + return NULL; + + memset(&pdata, 0, sizeof(pdata)); + pdata.index = index; + + /* Initial values for the request line and channel */ + dma_spec->chan_id = -1; + dma_spec->slave_id = -1; + + INIT_LIST_HEAD(&resource_list); + acpi_dev_get_resources(adev, &resource_list, + acpi_dma_parse_fixed_dma, &pdata); + acpi_dev_free_resource_list(&resource_list); + + if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0) + return NULL; + + mutex_lock(&acpi_dma_lock); + + list_for_each_entry(adma, &acpi_dma_list, dma_controllers) { + dma_spec->dev = adma->dev; + chan = adma->acpi_dma_xlate(dma_spec, adma); + if (chan) + break; + } + + mutex_unlock(&acpi_dma_lock); + return chan; +} +EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index); + +/** + * acpi_dma_request_slave_chan_by_name - Get the DMA slave channel + * @dev: struct device to get DMA request from + * @name: represents corresponding FixedDMA descriptor for @dev + * + * In order to support both Device Tree and ACPI in a single driver we + * translate the names "tx" and "rx" here based on the most common case where + * the first FixedDMA descriptor is TX and second is RX. + * + * Returns pointer to appropriate dma channel on success or NULL on error. + */ +struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev, + const char *name) +{ + size_t index; + + if (!strcmp(name, "tx")) + index = 0; + else if (!strcmp(name, "rx")) + index = 1; + else + return NULL; + + return acpi_dma_request_slave_chan_by_index(dev, index); +} +EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_name); + +/** + * acpi_dma_simple_xlate - Simple ACPI DMA engine translation helper + * @dma_spec: pointer to ACPI DMA specifier + * @adma: pointer to ACPI DMA controller data + * + * A simple translation function for ACPI based devices. Passes &struct + * dma_spec to the DMA controller driver provided filter function. Returns + * pointer to the channel if found or %NULL otherwise. + */ +struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec, + struct acpi_dma *adma) +{ + struct acpi_dma_filter_info *info = adma->data; + + if (!info || !info->filter_fn) + return NULL; + + return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec); +} +EXPORT_SYMBOL_GPL(acpi_dma_simple_xlate); |