From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Hershberger Date: Wed, 7 Mar 2018 15:27:30 -0600 Subject: [U-Boot] [PATCH v5 02/15] dma: add channels support In-Reply-To: <20180305200546.12744-3-noltari@gmail.com> References: <20180212163858.25601-1-noltari@gmail.com> <20180305200546.12744-1-noltari@gmail.com> <20180305200546.12744-3-noltari@gmail.com> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: u-boot@lists.denx.de On Mon, Mar 5, 2018 at 2:05 PM, Álvaro Fernández Rojas wrote: > 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 > Reviewed-by: Simon Glass > --- > v5: remove unneeded dma.h include > v4: no changes > 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 faa27a3a56..b5109aafc9 100644 > --- a/drivers/dma/dma-uclass.c > +++ b/drivers/dma/dma-uclass.c > @@ -1,23 +1,199 @@ > /* > * Direct Memory Access U-Class driver > * > - * (C) Copyright 2015 > - * Texas Instruments Incorporated, > - * > - * Author: Mugunthan V N > + * Copyright (C) 2018 Álvaro Fernández Rojas > + * Copyright (C) 2015 Texas Instruments Incorporated > + * Written by Mugunthan V N > * > * SPDX-License-Identifier: GPL-2.0+ > */ > > #include > #include > -#include > -#include > +#include > #include > +#include > #include > > 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; Isn't there a better error code you could return? Such as -ENOSYS like above? > + > + 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; Same here. > + > + 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 3429f65ec4..b334adb68b 100644 > --- a/include/dma-uclass.h > +++ b/include/dma-uclass.h > @@ -13,6 +13,8 @@ > > #include > > +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. > + */ I haven't seen any implementation of this. Will it return -EAGAIN in the case where the packet isn't available? > + 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, > + * Copyright (C) 2018 Álvaro Fernández Rojas > + * Copyright (C) 2015 Texas Instruments Incorporated > + * Written by Mugunthan V N > * > * SPDX-License-Identifier: GPL-2.0+ > */ > @@ -8,6 +9,9 @@ > #ifndef _DMA_H_ > #define _DMA_H_ > > +#include > +#include > + > /* > * 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 > -- > 2.11.0 > > _______________________________________________ > U-Boot mailing list > U-Boot at lists.denx.de > https://lists.denx.de/listinfo/u-boot