This adds channels support for dma controllers that have multiple channels which can transfer data to/from different devices (enet, usb...).
Signed-off-by: Álvaro Fernández Rojas noltari@gmail.com --- v3: Introduce changes reported by Simon Glass: - Improve dma-uclass.h documentation. - Switch to live tree API.
drivers/dma/Kconfig | 7 ++ drivers/dma/dma-uclass.c | 188 +++++++++++++++++++++++++++++++++++++++++++++-- include/dma-uclass.h | 78 ++++++++++++++++++++ include/dma.h | 174 ++++++++++++++++++++++++++++++++++++++++++- 4 files changed, 439 insertions(+), 8 deletions(-)
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index 1b92c7789d..21b2c0dcaa 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -12,6 +12,13 @@ config DMA buses that is used to transfer data to and from memory. The uclass interface is defined in include/dma.h.
+config DMA_CHANNELS + bool "Enable DMA channels support" + depends on DMA + help + Enable channels support for DMA. Some DMA controllers have multiple + channels which can either transfer data to/from different devices. + config TI_EDMA3 bool "TI EDMA3 driver" help diff --git a/drivers/dma/dma-uclass.c b/drivers/dma/dma-uclass.c index 6fd4e1b35d..f4ba883b12 100644 --- a/drivers/dma/dma-uclass.c +++ b/drivers/dma/dma-uclass.c @@ -1,24 +1,200 @@ /* * Direct Memory Access U-Class driver * - * (C) Copyright 2015 - * Texas Instruments Incorporated, <www.ti.com> - * - * Author: Mugunthan V N mugunthanvnm@ti.com + * Copyright (C) 2018 Álvaro Fernández Rojas noltari@gmail.com + * Copyright (C) 2015 Texas Instruments Incorporated <www.ti.com> + * Written by Mugunthan V N mugunthanvnm@ti.com * * SPDX-License-Identifier: GPL-2.0+ */
#include <common.h> #include <dm.h> -#include <dm/uclass-internal.h> -#include <dm/device-internal.h> +#include <dm/read.h> #include <dma.h> #include <dma-uclass.h> +#include <dt-structs.h> #include <errno.h>
DECLARE_GLOBAL_DATA_PTR;
+#ifdef CONFIG_DMA_CHANNELS +static inline struct dma_ops *dma_dev_ops(struct udevice *dev) +{ + return (struct dma_ops *)dev->driver->ops; +} + +# if CONFIG_IS_ENABLED(OF_CONTROL) +# if CONFIG_IS_ENABLED(OF_PLATDATA) +int dma_get_by_index_platdata(struct udevice *dev, int index, + struct phandle_1_arg *cells, struct dma *dma) +{ + int ret; + + if (index != 0) + return -ENOSYS; + ret = uclass_get_device(UCLASS_DMA, 0, &dma->dev); + if (ret) + return ret; + dma->id = cells[0].id; + + return 0; +} +# else +static int dma_of_xlate_default(struct dma *dma, + struct ofnode_phandle_args *args) +{ + debug("%s(dma=%p)\n", __func__, dma); + + if (args->args_count > 1) { + pr_err("Invaild args_count: %d\n", args->args_count); + return -EINVAL; + } + + if (args->args_count) + dma->id = args->args[0]; + else + dma->id = 0; + + return 0; +} + +int dma_get_by_index(struct udevice *dev, int index, struct dma *dma) +{ + int ret; + struct ofnode_phandle_args args; + struct udevice *dev_dma; + const struct dma_ops *ops; + + debug("%s(dev=%p, index=%d, dma=%p)\n", __func__, dev, index, dma); + + assert(dma); + dma->dev = NULL; + + ret = dev_read_phandle_with_args(dev, "dmas", "#dma-cells", 0, index, + &args); + if (ret) { + pr_err("%s: dev_read_phandle_with_args failed: err=%d\n", + __func__, ret); + return ret; + } + + ret = uclass_get_device_by_ofnode(UCLASS_DMA, args.node, &dev_dma); + if (ret) { + pr_err("%s: uclass_get_device_by_ofnode failed: err=%d\n", + __func__, ret); + return ret; + } + + dma->dev = dev_dma; + + ops = dma_dev_ops(dev_dma); + + if (ops->of_xlate) + ret = ops->of_xlate(dma, &args); + else + ret = dma_of_xlate_default(dma, &args); + if (ret) { + pr_err("of_xlate() failed: %d\n", ret); + return ret; + } + + return dma_request(dev_dma, dma); +} +# endif /* OF_PLATDATA */ + +int dma_get_by_name(struct udevice *dev, const char *name, struct dma *dma) +{ + int index; + + debug("%s(dev=%p, name=%s, dma=%p)\n", __func__, dev, name, dma); + dma->dev = NULL; + + index = dev_read_stringlist_search(dev, "dma-names", name); + if (index < 0) { + pr_err("dev_read_stringlist_search() failed: %d\n", index); + return index; + } + + return dma_get_by_index(dev, index, dma); +} +# endif /* OF_CONTROL */ + +int dma_request(struct udevice *dev, struct dma *dma) +{ + struct dma_ops *ops = dma_dev_ops(dev); + + debug("%s(dev=%p, dma=%p)\n", __func__, dev, dma); + + dma->dev = dev; + + if (!ops->request) + return 0; + + return ops->request(dma); +} + +int dma_free(struct dma *dma) +{ + struct dma_ops *ops = dma_dev_ops(dma->dev); + + debug("%s(dma=%p)\n", __func__, dma); + + if (!ops->free) + return 0; + + return ops->free(dma); +} + +int dma_enable(struct dma *dma) +{ + struct dma_ops *ops = dma_dev_ops(dma->dev); + + debug("%s(dma=%p)\n", __func__, dma); + + if (!ops->enable) + return -ENOSYS; + + return ops->enable(dma); +} + +int dma_disable(struct dma *dma) +{ + struct dma_ops *ops = dma_dev_ops(dma->dev); + + debug("%s(dma=%p)\n", __func__, dma); + + if (!ops->disable) + return -ENOSYS; + + return ops->disable(dma); +} + +int dma_receive(struct dma *dma, void **dst) +{ + struct dma_ops *ops = dma_dev_ops(dma->dev); + + debug("%s(dma=%p)\n", __func__, dma); + + if (!ops->receive) + return -1; + + return ops->receive(dma, dst); +} + +int dma_send(struct dma *dma, void *src, size_t len) +{ + struct dma_ops *ops = dma_dev_ops(dma->dev); + + debug("%s(dma=%p)\n", __func__, dma); + + if (!ops->send) + return -1; + + return ops->send(dma, src, len); +} +#endif /* CONFIG_DMA_CHANNELS */ + int dma_get_device(u32 transfer_type, struct udevice **devp) { struct udevice *dev; diff --git a/include/dma-uclass.h b/include/dma-uclass.h index abf750a5ce..38f0fe94f8 100644 --- a/include/dma-uclass.h +++ b/include/dma-uclass.h @@ -13,6 +13,8 @@
#include <dma.h>
+struct ofnode_phandle_args; + /* * struct dma_ops - Driver model DMA operations * @@ -20,6 +22,82 @@ * driver model. */ struct dma_ops { +#ifdef CONFIG_DMA_CHANNELS + /** + * of_xlate - Translate a client's device-tree (OF) DMA specifier. + * + * The DMA core calls this function as the first step in implementing + * a client's dma_get_by_*() call. + * + * If this function pointer is set to NULL, the DMA core will use a + * default implementation, which assumes #dma-cells = <1>, and that + * the DT cell contains a simple integer DMA Channel. + * + * At present, the DMA API solely supports device-tree. If this + * changes, other xxx_xlate() functions may be added to support those + * other mechanisms. + * + * @dma: The dma struct to hold the translation result. + * @args: The dma specifier values from device tree. + * @return 0 if OK, or a negative error code. + */ + int (*of_xlate)(struct dma *dma, + struct ofnode_phandle_args *args); + /** + * request - Request a translated DMA. + * + * The DMA core calls this function as the second step in + * implementing a client's dma_get_by_*() call, following a successful + * xxx_xlate() call, or as the only step in implementing a client's + * dma_request() call. + * + * @dma: The DMA struct to request; this has been filled in by + * a previoux xxx_xlate() function call, or by the caller of + * dma_request(). + * @return 0 if OK, or a negative error code. + */ + int (*request)(struct dma *dma); + /** + * free - Free a previously requested dma. + * + * This is the implementation of the client dma_free() API. + * + * @dma: The DMA to free. + * @return 0 if OK, or a negative error code. + */ + int (*free)(struct dma *dma); + /** + * enable() - Enable a DMA Channel. + * + * @dma: The DMA Channel to manipulate. + * @return zero on success, or -ve error code. + */ + int (*enable)(struct dma *dma); + /** + * disable() - Disable a DMA Channel. + * + * @dma: The DMA Channel to manipulate. + * @return zero on success, or -ve error code. + */ + int (*disable)(struct dma *dma); + /** + * receive() - Receive a DMA transfer. + * + * @dma: The DMA Channel to manipulate. + * @dst: The destination pointer. + * @return zero on success, or -ve error code. + */ + int (*receive)(struct dma *dma, void **dst); + /** + * send() - Send a DMA transfer. + * + * @dma: The DMA Channel to manipulate. + * @src: The source pointer. + * @len: Length of the data to be sent (number of bytes). + * @return zero on success, or -ve error code. + */ + int (*send)(struct dma *dma, void *src, size_t len); +#endif /* CONFIG_DMA_CHANNELS */ /** * transfer() - Issue a DMA transfer. The implementation must * wait until the transfer is done. diff --git a/include/dma.h b/include/dma.h index 89320f10d9..bf8123fa9e 100644 --- a/include/dma.h +++ b/include/dma.h @@ -1,6 +1,7 @@ /* - * (C) Copyright 2015 - * Texas Instruments Incorporated, <www.ti.com> + * Copyright (C) 2018 Álvaro Fernández Rojas noltari@gmail.com + * Copyright (C) 2015 Texas Instruments Incorporated <www.ti.com> + * Written by Mugunthan V N mugunthanvnm@ti.com * * SPDX-License-Identifier: GPL-2.0+ */ @@ -8,6 +9,9 @@ #ifndef _DMA_H_ #define _DMA_H_
+#include <linux/errno.h> +#include <linux/types.h> + /* * enum dma_direction - dma transfer direction indicator * @DMA_MEM_TO_MEM: Memcpy mode @@ -37,6 +41,172 @@ struct dma_dev_priv { u32 supported; };
+#ifdef CONFIG_DMA_CHANNELS +/** + * A DMA is a feature of computer systems that allows certain hardware + * subsystems to access main system memory, independent of the CPU. + * DMA channels are typically generated externally to the HW module + * consuming them, by an entity this API calls a DMA provider. This API + * provides a standard means for drivers to enable and disable DMAs, and to + * copy, send and receive data using DMA. + * + * A driver that implements UCLASS_DMA is a DMA provider. A provider will + * often implement multiple separate DMAs, since the hardware it manages + * often has this capability. dma_uclass.h describes the interface which + * DMA providers must implement. + * + * DMA consumers/clients are the HW modules driven by the DMA channels. This + * header file describes the API used by drivers for those HW modules. + */ + +struct udevice; + +/** + * struct dma - A handle to (allowing control of) a single DMA. + * + * Clients provide storage for DMA handles. The content of the structure is + * managed solely by the DMA API and DMA drivers. A DMA struct is + * initialized by "get"ing the DMA struct. The DMA struct is passed to all + * other DMA APIs to identify which DMA channel to operate upon. + * + * @dev: The device which implements the DMA channel. + * @id: The DMA channel ID within the provider. + * + * Currently, the DMA API assumes that a single integer ID is enough to + * identify and configure any DMA channel for any DMA provider. If this + * assumption becomes invalid in the future, the struct could be expanded to + * either (a) add more fields to allow DMA providers to store additional + * information, or (b) replace the id field with an opaque pointer, which the + * provider would dynamically allocated during its .of_xlate op, and process + * during is .request op. This may require the addition of an extra op to clean + * up the allocation. + */ +struct dma { + struct udevice *dev; + /* + * Written by of_xlate. We assume a single id is enough for now. In the + * future, we might add more fields here. + */ + unsigned long id; +}; + +# if CONFIG_IS_ENABLED(OF_CONTROL) && CONFIG_IS_ENABLED(DMA) +struct phandle_1_arg; +int dma_get_by_index_platdata(struct udevice *dev, int index, + struct phandle_1_arg *cells, struct dma *dma); + +/** + * dma_get_by_index - Get/request a DMA by integer index. + * + * This looks up and requests a DMA. The index is relative to the client + * device; each device is assumed to have n DMAs associated with it somehow, + * and this function finds and requests one of them. The mapping of client + * device DMA indices to provider DMAs may be via device-tree properties, + * board-provided mapping tables, or some other mechanism. + * + * @dev: The client device. + * @index: The index of the DMA to request, within the client's list of + * DMA channels. + * @dma: A pointer to a DMA struct to initialize. + * @return 0 if OK, or a negative error code. + */ +int dma_get_by_index(struct udevice *dev, int index, struct dma *dma); + +/** + * dma_get_by_name - Get/request a DMA by name. + * + * This looks up and requests a DMA. The name is relative to the client + * device; each device is assumed to have n DMAs associated with it somehow, + * and this function finds and requests one of them. The mapping of client + * device DMA names to provider DMAs may be via device-tree properties, + * board-provided mapping tables, or some other mechanism. + * + * @dev: The client device. + * @name: The name of the DMA to request, within the client's list of + * DMA channels. + * @dma: A pointer to a DMA struct to initialize. + * @return 0 if OK, or a negative error code. + */ +int dma_get_by_name(struct udevice *dev, const char *name, struct dma *dma); +# else +static inline int dma_get_by_index(struct udevice *dev, int index, + struct dma *dma) +{ + return -ENOSYS; +} + +static inline int dma_get_by_name(struct udevice *dev, const char *name, + struct dma *dma) +{ + return -ENOSYS; +} +# endif + +/** + * dma_request - Request a DMA by provider-specific ID. + * + * This requests a DMA using a provider-specific ID. Generally, this function + * should not be used, since dma_get_by_index/name() provide an interface that + * better separates clients from intimate knowledge of DMA providers. + * However, this function may be useful in core SoC-specific code. + * + * @dev: The DMA provider device. + * @dma: A pointer to a DMA struct to initialize. The caller must + * have already initialized any field in this struct which the + * DMA provider uses to identify the DMA channel. + * @return 0 if OK, or a negative error code. + */ +int dma_request(struct udevice *dev, struct dma *dma); + +/** + * dma_free - Free a previously requested DMA. + * + * @dma: A DMA struct that was previously successfully requested by + * dma_request/get_by_*(). + * @return 0 if OK, or a negative error code. + */ +int dma_free(struct dma *dma); + +/** + * dma_enable() - Enable (turn on) a DMA channel. + * + * @dma: A DMA struct that was previously successfully requested by + * dma_request/get_by_*(). + * @return zero on success, or -ve error code. + */ +int dma_enable(struct dma *dma); + +/** + * dma_disable() - Disable (turn off) a DMA channel. + * + * @dma: A DMA struct that was previously successfully requested by + * dma_request/get_by_*(). + * @return zero on success, or -ve error code. + */ +int dma_disable(struct dma *dma); + +/** + * dma_receive() - Receive a DMA transfer. + * + * @dma: A DMA struct that was previously successfully requested by + * dma_request/get_by_*(). + * @dst: The destination pointer. + * @return zero on success, or -ve error code. + */ +int dma_receive(struct dma *dma, void **dst); + +/** + * dma_send() - Send a DMA transfer. + * + * @dma: A DMA struct that was previously successfully requested by + * dma_request/get_by_*(). + * @src: The source pointer. + * @len: Length of the data to be sent (number of bytes). + * @return zero on success, or -ve error code. + */ +int dma_send(struct dma *dma, void *src, size_t len); +#endif /* CONFIG_DMA_CHANNELS */ + /* * dma_get_device - get a DMA device which supports transfer * type of transfer_type