[U-Boot] [RFC v2 02/15] dma: add channels support

Simon Glass
2018-02-20T18:49:14Z

Hi Alvaro,

On 20 February 2018 at 10:46, Álvaro Fernández Rojas <noltari@gmail.com> 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 <noltari@gmail.com>
> ---
> v2: Introduce changes reported by Vignesh:
> - Respect current dma implementation.
> - Let dma_memcpy find a compatible dma device.
>
> drivers/dma/Kconfig | 7 ++
> drivers/dma/dma-uclass.c | 177 +++++++++++++++++++++++++++++++++++++++++++++++
> include/dma-uclass.h | 77 +++++++++++++++++++++
> include/dma.h | 169 ++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 430 insertions(+)
>
> 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..a16c3a786c 100644
> --- a/drivers/dma/dma-uclass.c
> +++ b/drivers/dma/dma-uclass.c
> @@ -15,10 +15,187 @@
> #include <dm/device-internal.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_2_cell *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 fdtdec_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 fdtdec_phandle_args args;
> + struct udevice *dev_dma;
> + struct dma_ops *ops;
> +
> + debug("%s(dev=%p, index=%d, dma=%p)\n", __func__, dev, index, dma);
> +
> + assert(dma);
> + ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev_of_offset(dev),
> + "dmas", "#dma-cells", 0, index,
> + &args);

Can you please use the livetree API? E.g. see dev_read_phandle_with_args()

Also please move this into an ofdata_to_platdata function rather than
doing it each time this function is called.

> + if (ret) {
> + pr_err("%s: fdtdec_parse_phandle_with_args failed: err=%d\n",
> + __func__, ret);
> + return ret;
> + }
> +
> + ret = uclass_get_device_by_of_offset(UCLASS_DMA, args.node, &dev_dma);
> + if (ret) {
> + pr_err("%s: uclass_get_device_by_of_offset 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);
> +
> + index = fdt_stringlist_search(gd->fdt_blob, dev_of_offset(dev),
> + "dma-names", name);

dev_read...

> + if (index < 0) {
> + pr_err("fdt_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 e29ad103f2..5faec69207 100644
> --- a/include/dma-uclass.h
> +++ b/include/dma-uclass.h
> @@ -12,6 +12,7 @@
> /* See dma.h for background documentation. */
>
> #include <dma.h>
> +#include <fdtdec.h>
>
> /*
> * struct dma_ops - Driver model DMA operations
> @@ -20,6 +21,82 @@
> * 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 fdtdec_phandle_args *args);

Use new livetree struct here

Regards,
Simon