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

["Álvaro Fernández Rojas" <noltari@gmail.com>]

Hi Simon,

El 20/02/2018 a las 19:49, Simon Glass escribió:
> 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.
Ok, I did this some time ago and I used an older version of clk-uclass 
as a starting point.
I will switch to livetree in the next patch version.
>
>> +       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...
Ok.
>
>> +       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
Ok.
>
> Regards,
> Simon
Regards,
Álvaro.