diff options
44 files changed, 2088 insertions, 1181 deletions
diff --git a/Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt b/Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt index 040f365954cc..e7780a186a36 100644 --- a/Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt +++ b/Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt @@ -1,7 +1,13 @@ * Renesas USB DMA Controller Device Tree bindings Required Properties: -- compatible: must contain "renesas,usb-dmac" +-compatible: "renesas,<soctype>-usb-dmac", "renesas,usb-dmac" as fallback. + Examples with soctypes are: + - "renesas,r8a7790-usb-dmac" (R-Car H2) + - "renesas,r8a7791-usb-dmac" (R-Car M2-W) + - "renesas,r8a7793-usb-dmac" (R-Car M2-N) + - "renesas,r8a7794-usb-dmac" (R-Car E2) + - "renesas,r8a7795-usb-dmac" (R-Car H3) - reg: base address and length of the registers block for the DMAC - interrupts: interrupt specifiers for the DMAC, one for each entry in interrupt-names. @@ -15,7 +21,7 @@ Required Properties: Example: R8A7790 (R-Car H2) USB-DMACs usb_dmac0: dma-controller@e65a0000 { - compatible = "renesas,usb-dmac"; + compatible = "renesas,r8a7790-usb-dmac", "renesas,usb-dmac"; reg = <0 0xe65a0000 0 0x100>; interrupts = <0 109 IRQ_TYPE_LEVEL_HIGH 0 109 IRQ_TYPE_LEVEL_HIGH>; diff --git a/Documentation/devicetree/bindings/dma/stm32-dma.txt b/Documentation/devicetree/bindings/dma/stm32-dma.txt new file mode 100644 index 000000000000..70cd13f1588a --- /dev/null +++ b/Documentation/devicetree/bindings/dma/stm32-dma.txt @@ -0,0 +1,82 @@ +* STMicroelectronics STM32 DMA controller + +The STM32 DMA is a general-purpose direct memory access controller capable of +supporting 8 independent DMA channels. Each channel can have up to 8 requests. + +Required properties: +- compatible: Should be "st,stm32-dma" +- reg: Should contain DMA registers location and length. This should include + all of the per-channel registers. +- interrupts: Should contain all of the per-channel DMA interrupts in + ascending order with respect to the DMA channel index. +- clocks: Should contain the input clock of the DMA instance. +- #dma-cells : Must be <4>. See DMA client paragraph for more details. + +Optional properties: +- resets: Reference to a reset controller asserting the DMA controller +- st,mem2mem: boolean; if defined, it indicates that the controller supports + memory-to-memory transfer + +Example: + + dma2: dma-controller@40026400 { + compatible = "st,stm32-dma"; + reg = <0x40026400 0x400>; + interrupts = <56>, + <57>, + <58>, + <59>, + <60>, + <68>, + <69>, + <70>; + clocks = <&clk_hclk>; + #dma-cells = <4>; + st,mem2mem; + resets = <&rcc 150>; + }; + +* DMA client + +DMA clients connected to the STM32 DMA controller must use the format +described in the dma.txt file, using a five-cell specifier for each +channel: a phandle plus four integer cells. +The four cells in order are: + +1. The channel id +2. The request line number +3. A 32bit mask specifying the DMA channel configuration which are device + dependent: + -bit 9: Peripheral Increment Address + 0x0: no address increment between transfers + 0x1: increment address between transfers + -bit 10: Memory Increment Address + 0x0: no address increment between transfers + 0x1: increment address between transfers + -bit 15: Peripheral Increment Offset Size + 0x0: offset size is linked to the peripheral bus width + 0x1: offset size is fixed to 4 (32-bit alignment) + -bit 16-17: Priority level + 0x0: low + 0x1: medium + 0x2: high + 0x3: very high +5. A 32bit mask specifying the DMA FIFO threshold configuration which are device + dependent: + -bit 0-1: Fifo threshold + 0x0: 1/4 full FIFO + 0x1: 1/2 full FIFO + 0x2: 3/4 full FIFO + 0x3: full FIFO + +Example: + + usart1: serial@40011000 { + compatible = "st,stm32-usart", "st,stm32-uart"; + reg = <0x40011000 0x400>; + interrupts = <37>; + clocks = <&clk_pclk2>; + dmas = <&dma2 2 4 0x10400 0x3>, + <&dma2 7 5 0x10200 0x3>; + dma-names = "rx", "tx"; + }; diff --git a/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt b/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt index b152a75dceae..aead5869a28d 100644 --- a/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt +++ b/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt @@ -14,6 +14,10 @@ The DMA controller node need to have the following poroperties: Optional properties: - ti,dma-safe-map: Safe routing value for unused request lines +- ti,reserved-dma-request-ranges: DMA request ranges which should not be used + when mapping xbar input to DMA request, they are either + allocated to be used by for example the DSP or they are used as + memcpy channels in eDMA. Notes: When requesting channel via ti,dra7-dma-crossbar, the DMA clinet must request @@ -46,6 +50,8 @@ sdma_xbar: dma-router@4a002b78 { #dma-cells = <1>; dma-requests = <205>; ti,dma-safe-map = <0>; + /* Protect the sDMA request ranges: 10-14 and 100-126 */ + ti,reserved-dma-request-ranges = <10 5>, <100 27>; dma-masters = <&sdma>; }; diff --git a/Documentation/dmaengine/client.txt b/Documentation/dmaengine/client.txt index 11fb87ff6cd0..9e33189745f0 100644 --- a/Documentation/dmaengine/client.txt +++ b/Documentation/dmaengine/client.txt @@ -22,25 +22,14 @@ The slave DMA usage consists of following steps: Channel allocation is slightly different in the slave DMA context, client drivers typically need a channel from a particular DMA controller only and even in some cases a specific channel is desired. - To request a channel dma_request_channel() API is used. + To request a channel dma_request_chan() API is used. Interface: - struct dma_chan *dma_request_channel(dma_cap_mask_t mask, - dma_filter_fn filter_fn, - void *filter_param); - where dma_filter_fn is defined as: - typedef bool (*dma_filter_fn)(struct dma_chan *chan, void *filter_param); + struct dma_chan *dma_request_chan(struct device *dev, const char *name); - The 'filter_fn' parameter is optional, but highly recommended for - slave and cyclic channels as they typically need to obtain a specific - DMA channel. - - When the optional 'filter_fn' parameter is NULL, dma_request_channel() - simply returns the first channel that satisfies the capability mask. - - Otherwise, the 'filter_fn' routine will be called once for each free - channel which has a capability in 'mask'. 'filter_fn' is expected to - return 'true' when the desired DMA channel is found. + Which will find and return the 'name' DMA channel associated with the 'dev' + device. The association is done via DT, ACPI or board file based + dma_slave_map matching table. A channel allocated via this interface is exclusive to the caller, until dma_release_channel() is called. @@ -128,7 +117,7 @@ The slave DMA usage consists of following steps: transaction. For cyclic DMA, a callback function may wish to terminate the - DMA via dmaengine_terminate_all(). + DMA via dmaengine_terminate_async(). Therefore, it is important that DMA engine drivers drop any locks before calling the callback function which may cause a @@ -166,12 +155,29 @@ The slave DMA usage consists of following steps: Further APIs: -1. int dmaengine_terminate_all(struct dma_chan *chan) +1. int dmaengine_terminate_sync(struct dma_chan *chan) + int dmaengine_terminate_async(struct dma_chan *chan) + int dmaengine_terminate_all(struct dma_chan *chan) /* DEPRECATED */ This causes all activity for the DMA channel to be stopped, and may discard data in the DMA FIFO which hasn't been fully transferred. No callback functions will be called for any incomplete transfers. + Two variants of this function are available. + + dmaengine_terminate_async() might not wait until the DMA has been fully + stopped or until any running complete callbacks have finished. But it is + possible to call dmaengine_terminate_async() from atomic context or from + within a complete callback. dmaengine_synchronize() must be called before it + is safe to free the memory accessed by the DMA transfer or free resources + accessed from within the complete callback. + + dmaengine_terminate_sync() will wait for the transfer and any running + complete callbacks to finish before it returns. But the function must not be + called from atomic context or from within a complete callback. + + dmaengine_terminate_all() is deprecated and should not be used in new code. + 2. int dmaengine_pause(struct dma_chan *chan) This pauses activity on the DMA channel without data loss. @@ -197,3 +203,20 @@ Further APIs: a running DMA channel. It is recommended that DMA engine users pause or stop (via dmaengine_terminate_all()) the channel before using this API. + +5. void dmaengine_synchronize(struct dma_chan *chan) + + Synchronize the termination of the DMA channel to the current context. + + This function should be used after dmaengine_terminate_async() to synchronize + the termination of the DMA channel to the current context. The function will + wait for the transfer and any running complete callbacks to finish before it + returns. + + If dmaengine_terminate_async() is used to stop the DMA channel this function + must be called before it is safe to free memory accessed by previously + submitted descriptors or to free any resources accessed within the complete + callback of previously submitted descriptors. + + The behavior of this function is undefined if dma_async_issue_pending() has + been called between dmaengine_terminate_async() and this function. diff --git a/Documentation/dmaengine/provider.txt b/Documentation/dmaengine/provider.txt index 67d4ce4df109..122b7f4876bb 100644 --- a/Documentation/dmaengine/provider.txt +++ b/Documentation/dmaengine/provider.txt @@ -327,8 +327,24 @@ supported. * device_terminate_all - Aborts all the pending and ongoing transfers on the channel - - This command should operate synchronously on the channel, - terminating right away all the channels + - For aborted transfers the complete callback should not be called + - Can be called from atomic context or from within a complete + callback of a descriptor. Must not sleep. Drivers must be able + to handle this correctly. + - Termination may be asynchronous. The driver does not have to + wait until the currently active transfer has completely stopped. + See device_synchronize. + + * device_synchronize + - Must synchronize the termination of a channel to the current + context. + - Must make sure that memory for previously submitted + descriptors is no longer accessed by the DMA controller. + - Must make sure that all complete callbacks for previously + submitted descriptors have finished running and none are + scheduled to run. + - May sleep. + Misc notes (stuff that should be documented, but don't really know where to put them) diff --git a/arch/arm/configs/stm32_defconfig b/arch/arm/configs/stm32_defconfig index 4725fab562cb..ec5250547d14 100644 --- a/arch/arm/configs/stm32_defconfig +++ b/arch/arm/configs/stm32_defconfig @@ -54,6 +54,8 @@ CONFIG_NEW_LEDS=y CONFIG_LEDS_CLASS=y CONFIG_LEDS_TRIGGERS=y CONFIG_LEDS_TRIGGER_HEARTBEAT=y +CONFIG_DMADEVICES=y +CONFIG_STM32_DMA=y # CONFIG_FILE_LOCKING is not set # CONFIG_DNOTIFY is not set # CONFIG_INOTIFY_USER is not set diff --git a/drivers/dca/dca-core.c b/drivers/dca/dca-core.c index 819dfda88236..7afbb28d6a0f 100644 --- a/drivers/dca/dca-core.c +++ b/drivers/dca/dca-core.c @@ -321,7 +321,8 @@ EXPORT_SYMBOL_GPL(dca_get_tag); * @ops - pointer to struct of dca operation function pointers * @priv_size - size of extra mem to be added for provider's needs */ -struct dca_provider *alloc_dca_provider(struct dca_ops *ops, int priv_size) +struct dca_provider *alloc_dca_provider(const struct dca_ops *ops, + int priv_size) { struct dca_provider *dca; int alloc_size; diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index e6cd1a32025a..3a8ce67910c2 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -431,6 +431,18 @@ config STE_DMA40 help Support for ST-Ericsson DMA40 controller +config STM32_DMA + bool "STMicroelectronics STM32 DMA support" + depends on ARCH_STM32 + select DMA_ENGINE + select DMA_OF + select DMA_VIRTUAL_CHANNELS + help + Enable support for the on-chip DMA controller on STMicroelectronics + STM32 MCUs. + If you have a board based on such a MCU and wish to use DMA say Y or M + here. + config S3C24XX_DMAC tristate "Samsung S3C24XX DMA support" depends on ARCH_S3C24XX diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile index ef9c099bd2b6..2dd0a067a0ca 100644 --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile @@ -56,6 +56,7 @@ obj-$(CONFIG_QCOM_BAM_DMA) += qcom_bam_dma.o obj-$(CONFIG_RENESAS_DMA) += sh/ obj-$(CONFIG_SIRF_DMA) += sirf-dma.o obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o +obj-$(CONFIG_STM32_DMA) += stm32-dma.o obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c index 16d0daa058a5..eed6bda01790 100644 --- a/drivers/dma/acpi-dma.c +++ b/drivers/dma/acpi-dma.c @@ -15,6 +15,7 @@ #include <linux/device.h> #include <linux/err.h> #include <linux/module.h> +#include <linux/kernel.h> #include <linux/list.h> #include <linux/mutex.h> #include <linux/slab.h> @@ -72,7 +73,9 @@ static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp, 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) + if (si->mmio_base_low != lower_32_bits(mem) || + si->mmio_base_high != upper_32_bits(mem) || + si->gsi_interrupt != irq) return 0; dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n", diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index 370c661c7d7b..39f59666f93f 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -863,8 +863,12 @@ at_xdmac_interleaved_queue_desc(struct dma_chan *chan, * access. Hopefully we can access DDR through both ports (at least on * SAMA5D4x), so we can use the same interface for source and dest, * that solves the fact we don't know the direction. + * ERRATA: Even if useless for memory transfers, the PERID has to not + * match the one of another channel. If not, it could lead to spurious + * flag status. */ - u32 chan_cc = AT_XDMAC_CC_DIF(0) + u32 chan_cc = AT_XDMAC_CC_PERID(0x3f) + | AT_XDMAC_CC_DIF(0) | AT_XDMAC_CC_SIF(0) | AT_XDMAC_CC_MBSIZE_SIXTEEN | AT_XDMAC_CC_TYPE_MEM_TRAN; @@ -1041,8 +1045,12 @@ at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, * access DDR through both ports (at least on SAMA5D4x), so we can use * the same interface for source and dest, that solves the fact we * don't know the direction. + * ERRATA: Even if useless for memory transfers, the PERID has to not + * match the one of another channel. If not, it could lead to spurious + * flag status. */ - u32 chan_cc = AT_XDMAC_CC_DAM_INCREMENTED_AM + u32 chan_cc = AT_XDMAC_CC_PERID(0x3f) + | AT_XDMAC_CC_DAM_INCREMENTED_AM | AT_XDMAC_CC_SAM_INCREMENTED_AM | AT_XDMAC_CC_DIF(0) | AT_XDMAC_CC_SIF(0) @@ -1143,8 +1151,12 @@ static struct at_xdmac_desc *at_xdmac_memset_create_desc(struct dma_chan *chan, * access. Hopefully we can access DDR through both ports (at least on * SAMA5D4x), so we can use the same interface for source and dest, * that solves the fact we don't know the direction. + * ERRATA: Even if useless for memory transfers, the PERID has to not + * match the one of another channel. If not, it could lead to spurious + * flag status. */ - u32 chan_cc = AT_XDMAC_CC_DAM_UBS_AM + u32 chan_cc = AT_XDMAC_CC_PERID(0x3f) + | AT_XDMAC_CC_DAM_UBS_AM | AT_XDMAC_CC_SAM_INCREMENTED_AM | AT_XDMAC_CC_DIF(0) | AT_XDMAC_CC_SIF(0) @@ -1998,8 +2010,6 @@ static int at_xdmac_remove(struct platform_device *pdev) dma_async_device_unregister(&atxdmac->dma); clk_disable_unprepare(atxdmac->clk); - synchronize_irq(atxdmac->irq); - free_irq(atxdmac->irq, atxdmac->dma.dev); for (i = 0; i < atxdmac->dma.chancnt; i++) { diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c index 5b2395e7e04d..c3468094393e 100644 --- a/drivers/dma/dma-axi-dmac.c +++ b/drivers/dma/dma-axi-dmac.c @@ -307,6 +307,13 @@ static int axi_dmac_terminate_all(struct dma_chan *c) return 0; } +static void axi_dmac_synchronize(struct dma_chan *c) +{ + struct axi_dmac_chan *chan = to_axi_dmac_chan(c); + + vchan_synchronize(&chan->vchan); +} + static void axi_dmac_issue_pending(struct dma_chan *c) { struct axi_dmac_chan *chan = to_axi_dmac_chan(c); @@ -613,6 +620,7 @@ static int axi_dmac_probe(struct platform_device *pdev) dma_dev->device_prep_dma_cyclic = axi_dmac_prep_dma_cyclic; dma_dev->device_prep_interleaved_dma = axi_dmac_prep_interleaved; dma_dev->device_terminate_all = axi_dmac_terminate_all; + dma_dev->device_synchronize = axi_dmac_synchronize; dma_dev->dev = &pdev->dev; dma_dev->chancnt = 1; dma_dev->src_addr_widths = BIT(dmac->chan.src_width); diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 3ecec1445adf..c50a247be2e0 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -43,6 +43,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/platform_device.h> #include <linux/dma-mapping.h> #include <linux/init.h> #include <linux/module.h> @@ -265,8 +266,11 @@ static void dma_chan_put(struct dma_chan *chan) module_put(dma_chan_to_owner(chan)); /* This channel is not in use anymore, free it */ - if (!chan->client_count && chan->device->device_free_chan_resources) + if (!chan->client_count && chan->device->device_free_chan_resources) { + /* Make sure all operations have completed */ + dmaengine_synchronize(chan); chan->device->device_free_chan_resources(chan); + } /* If the channel is used via a DMA request router, free the mapping */ if (chan->router && chan->router->route_free) { @@ -493,6 +497,7 @@ int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps) caps->dst_addr_widths = device->dst_addr_widths; caps->directions = device->directions; caps->residue_granularity = device->residue_granularity; + caps->descriptor_reuse = device->descriptor_reuse; /* * Some devices implement only pause (e.g. to get residuum) but no @@ -511,7 +516,7 @@ static struct dma_chan *private_candidate(const dma_cap_mask_t *mask, { struct dma_chan *chan; - if (!__dma_device_satisfies_mask(dev, mask)) { + if (mask && !__dma_device_satisfies_mask(dev, mask)) { pr_debug("%s: wrong capabilities\n", __func__); return NULL; } @@ -542,6 +547,42 @@ static struct dma_chan *private_candidate(const dma_cap_mask_t *mask, return NULL; } +static struct dma_chan *find_candidate(struct dma_device *device, + const dma_cap_mask_t *mask, + dma_filter_fn fn, void *fn_param) +{ + struct dma_chan *chan = private_candidate(mask, device, fn, fn_param); + int err; + + if (chan) { + /* Found a suitable channel, try to grab, prep, and return it. + * We first set DMA_PRIVATE to disable balance_ref_count as this + * channel will not be published in the general-purpose + * allocator + */ + dma_cap_set(DMA_PRIVATE, device->cap_mask); + device->privatecnt++; + err = dma_chan_get(chan); + + if (err) { + if (err == -ENODEV) { + pr_debug("%s: %s module removed\n", __func__, + dma_chan_name(chan)); + list_del_rcu(&device->global_node); + } else + pr_debug("%s: failed to get %s: (%d)\n", + __func__, dma_chan_name(chan), err); + + if (--device->privatecnt == 0) + dma_cap_clear(DMA_PRIVATE, device->cap_mask); + + chan = ERR_PTR(err); + } + } + + return chan ? chan : ERR_PTR(-EPROBE_DEFER); +} + /** * dma_get_slave_channel - try to get specific channel exclusively * @chan: target channel @@ -580,7 +621,6 @@ struct dma_chan *dma_get_any_slave_channel(struct dma_device *device) { dma_cap_mask_t mask; struct dma_chan *chan; - int err; dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); @@ -588,23 +628,11 @@ struct dma_chan *dma_get_any_slave_channel(struct dma_device *device) /* lock against __dma_request_channel */ mutex_lock(&dma_list_mutex); - chan = private_candidate(&mask, device, NULL, NULL); - if (chan) { - dma_cap_set(DMA_PRIVATE, device->cap_mask); - device->privatecnt++; - err = dma_chan_get(chan); - if (err) { - pr_debug("%s: failed to get %s: (%d)\n", - __func__, dma_chan_name(chan), err); - chan = NULL; - if (--device->privatecnt == 0) - dma_cap_clear(DMA_PRIVATE, device->cap_mask); - } - } + chan = find_candidate(device, &mask, NULL, NULL); mutex_unlock(&dma_list_mutex); - return chan; + return IS_ERR(chan) ? NULL : chan; } EXPORT_SYMBOL_GPL(dma_get_any_slave_channel); @@ -621,35 +649,15 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, { struct dma_device *device, *_d; struct dma_chan *chan = NULL; - int err; /* Find a channel */ mutex_lock(&dma_list_mutex); list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { - chan = private_candidate(mask, device, fn, fn_param); - if (chan) { - /* Found a suitable channel, try to grab, prep, and - * return it. We first set DMA_PRIVATE to disable - * balance_ref_count as this channel will not be - * published in the general-purpose allocator - */ - dma_cap_set(DMA_PRIVATE, device->cap_mask); - device->privatecnt++; - err = dma_chan_get(chan); + chan = find_candidate(device, mask, fn, fn_param); + if (!IS_ERR(chan)) + break; - if (err == -ENODEV) { - pr_debug("%s: %s module removed\n", - __func__, dma_chan_name(chan)); - list_del_rcu(&device->global_node); - } else if (err) - pr_debug("%s: failed to get %s: (%d)\n", - __func__, dma_chan_name(chan), err); - else - break; - if (--device->privatecnt == 0) - dma_cap_clear(DMA_PRIVATE, device->cap_mask); - chan = NULL; - } + chan = NULL; } mutex_unlock(&dma_list_mutex); @@ -662,27 +670,73 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, } EXPORT_SYMBOL_GPL(__dma_request_channel); +static const struct dma_slave_map *dma_filter_match(struct dma_device *device, + const char *name, + struct device *dev) +{ + int i; + + if (!device->filter.mapcnt) + return NULL; + + for (i = 0; i < device->filter.mapcnt; i++) { + const struct dma_slave_map *map = &device->filter.map[i]; + + if (!strcmp(map->devname, dev_name(dev)) && + !strcmp(map->slave, name)) + return map; + } + + return NULL; +} + /** - * dma_request_slave_channel_reason - try to allocate an exclusive slave channel + * dma_request_chan - try to allocate an exclusive slave channel * @dev: pointer to client device structure * @name: slave channel name * * Returns pointer to appropriate DMA channel on success or an error pointer. */ -struct dma_chan *dma_request_slave_channel_reason(struct device *dev, - const char *name) +struct dma_chan *dma_request_chan(struct device *dev, const char *name) { + struct dma_device *d, *_d; + struct dma_chan *chan = NULL; + /* If device-tree is present get slave info from here */ if (dev->of_node) - return of_dma_request_slave_channel(dev->of_node, name); + chan = of_dma_request_slave_channel(dev->of_node, name); /* If device was enumerated by ACPI get slave info from here */ - if (ACPI_HANDLE(dev)) - return acpi_dma_request_slave_chan_by_name(dev, name); + if (has_acpi_companion(dev) && !chan) + chan = acpi_dma_request_slave_chan_by_name(dev, name); + + if (chan) { + /* Valid channel found or requester need to be deferred */ + if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER) + return chan; + } - return ERR_PTR(-ENODEV); + /* Try to find the channel via the DMA filter map(s) */ + mutex_lock(&dma_list_mutex); + list_for_each_entry_safe(d, _d, &dma_device_list, global_node) { + dma_cap_mask_t mask; + const struct dma_slave_map *map = dma_filter_match(d, name, dev); + + if (!map) + continue; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + chan = find_candidate(d, &mask, d->filter.fn, map->param); + if (!IS_ERR(chan)) + break; + } + mutex_unlock(&dma_list_mutex); + + return chan ? chan : ERR_PTR(-EPROBE_DEFER); } -EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason); +EXPORT_SYMBOL_GPL(dma_request_chan); /** * dma_request_slave_channel - try to allocate an exclusive slave channel @@ -694,17 +748,35 @@ EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason); struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name) { - struct dma_chan *ch = dma_request_slave_channel_reason(dev, name); + struct dma_chan *ch = dma_request_chan(dev, name); if (IS_ERR(ch)) return NULL; - dma_cap_set(DMA_PRIVATE, ch->device->cap_mask); - ch->device->privatecnt++; - return ch; } EXPORT_SYMBOL_GPL(dma_request_slave_channel); +/** + * dma_request_chan_by_mask - allocate a channel satisfying certain capabilities + * @mask: capabilities that the channel must |