Implement a DMA uclass so that the devices like ethernet, spi, mmc etc can offload the data transfers from/to the device and memory.
Signed-off-by: Mugunthan V N mugunthanvnm@ti.com --- drivers/dma/Kconfig | 15 +++++++++ drivers/dma/Makefile | 2 ++ drivers/dma/dma-uclass.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++ include/dm/uclass-id.h | 1 + include/dma.h | 81 ++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 177 insertions(+) create mode 100644 drivers/dma/dma-uclass.c create mode 100644 include/dma.h
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index e69de29..58cb6e9 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -0,0 +1,15 @@ +menu "DMA Support" + +config DMA + bool "Enable Driver Model for DMA drivers" + depends on DM + help + Enable driver model for DMA. DMA engines can do + asynchronous data transfers without involving the host + CPU. Currently, this framework can be used to offload + memory copies to and from devices like qspi, ethernet + etc Drivers provide methods to access the DMA devices + buses that is used to transfer data to and from memory. + The uclass interface is defined in include/dma.h. + +endmenu # menu "DMA Support" diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile index f95fe70..39b78b2 100644 --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile @@ -5,6 +5,8 @@ # SPDX-License-Identifier: GPL-2.0+ #
+obj-$(CONFIG_DMA) += dma-uclass.o + obj-$(CONFIG_FSLDMAFEC) += MCD_tasksInit.o MCD_dmaApi.o MCD_tasks.o obj-$(CONFIG_APBH_DMA) += apbh_dma.o obj-$(CONFIG_FSL_DMA) += fsl_dma.o diff --git a/drivers/dma/dma-uclass.c b/drivers/dma/dma-uclass.c new file mode 100644 index 0000000..0b3044e --- /dev/null +++ b/drivers/dma/dma-uclass.c @@ -0,0 +1,78 @@ +/* + * Direct Memory Access U-Class driver + * + * (C) Copyright 2015 + * Texas Instruments Incorporated, <www.ti.com> + * + * Author: Mugunthan V N mugunthanvnm@ti.com + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <dma.h> +#include <dm.h> +#include <dm/uclass-internal.h> +#include <dm/device-internal.h> +#include <errno.h> + +DECLARE_GLOBAL_DATA_PTR; + +int dma_get_device(struct udevice **devp, u32 transfer_type) +{ + struct udevice *dev = NULL; + int ret; + + for (ret = uclass_find_first_device(UCLASS_DMA, &dev); dev && !ret; + ret = uclass_find_next_device(&dev)) { + struct dma_dev_priv *uc_priv; + + ret = device_probe(dev); + if (ret) { + error("device probe error\n"); + continue; + } + + uc_priv = dev_get_uclass_priv(dev); + if (uc_priv->supported & transfer_type) + break; + } + + if (!dev) { + error("No DMA device found that supports %x type\n", + transfer_type); + return -ENODEV; + } + + *devp = dev; + + return ret; +} + +int dma_memcpy(void *dst, void *src, size_t len) +{ + struct udevice *dev; + const struct dma_ops *ops; + int ret; + + ret = dma_get_device(&dev, DMA_SUPPORTS_MEM_TO_MEM); + if (ret < 0) + return ret; + + ops = device_get_ops(dev); + if (!ops->transfer) + return -ENOSYS; + + /* Invalidate the area, so no writeback into the RAM races with DMA */ + invalidate_dcache_range((unsigned long)dst, (unsigned long)dst + + roundup(len, ARCH_DMA_MINALIGN)); + + return ops->transfer(dev, DMA_MEM_TO_MEM, dst, src, len); +} + +UCLASS_DRIVER(dma) = { + .id = UCLASS_DMA, + .name = "dma", + .flags = DM_UC_FLAG_SEQ_ALIAS, + .per_device_auto_alloc_size = sizeof(struct dma_dev_priv), +}; diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index 27fa0b6..9f5fcae 100644 --- a/include/dm/uclass-id.h +++ b/include/dm/uclass-id.h @@ -30,6 +30,7 @@ enum uclass_id { UCLASS_CPU, /* CPU, typically part of an SoC */ UCLASS_CROS_EC, /* Chrome OS EC */ UCLASS_DISPLAY_PORT, /* Display port video */ + UCLASS_DMA, /* Direct Memory Access */ UCLASS_RAM, /* RAM controller */ UCLASS_ETH, /* Ethernet device */ UCLASS_GPIO, /* Bank of general-purpose I/O pins */ diff --git a/include/dma.h b/include/dma.h new file mode 100644 index 0000000..4b7016f --- /dev/null +++ b/include/dma.h @@ -0,0 +1,81 @@ +/* + * (C) Copyright 2015 + * Texas Instruments Incorporated, <www.ti.com> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef _DMA_H_ +#define _DMA_H_ + +/* + * enum dma_direction - dma transfer direction indicator + * @DMA_MEM_TO_MEM: Memcpy mode + * @DMA_MEM_TO_DEV: From Memory to Device + * @DMA_DEV_TO_MEM: From Device to Memory + * @DMA_DEV_TO_DEV: From Device to Device + */ +enum dma_direction { + DMA_MEM_TO_MEM, + DMA_MEM_TO_DEV, + DMA_DEV_TO_MEM, + DMA_DEV_TO_DEV, +}; + +#define DMA_SUPPORTS_MEM_TO_MEM BIT(0) +#define DMA_SUPPORTS_MEM_TO_DEV BIT(1) +#define DMA_SUPPORTS_DEV_TO_MEM BIT(2) +#define DMA_SUPPORTS_DEV_TO_DEV BIT(3) + +/* + * struct dma_ops - Driver model DMA operations + * + * The uclass interface is implemented by all DMA devices which use + * driver model. + */ +struct dma_ops { + /* + * Get the current timer count + * + * @dev: The DMA device + * @direction: direction of data transfer should be one from + enum dma_direction + * @dst: Destination pointer + * @src: Source pointer + * @len: Length of the data to be copied. + * @return: 0 if OK, -ve on error + */ + int (*transfer)(struct udevice *dev, int direction, void *dst, + void *src, size_t len); +}; + +/* + * struct dma_dev_priv - information about a device used by the uclass + * + * @supported: mode of transfers that DMA can support + */ +struct dma_dev_priv { + u32 supported; +}; + +/* + * dma_get_device - get a DMA device which supports transfer + * type of transfer_type + * + * @devp - udevice pointer to return the found device + * @transfer_type - transfer type should be one/multiple of + * DMA_SUPPORTS_* + */ +int dma_get_device(struct udevice **devp, u32 transfer_type); + +/* + * dma_memcpy - try to use DMA to do a mem copy which will be + * much faster than CPU mem copy + * + * @dst - destination pointer + * @src - souce pointer + * @len - data length to be copied + */ +int dma_memcpy(void *dst, void *src, size_t len); + +#endif /* _DMA_H_ */