Re: [PATCH 08/11] mfd: flexcard: add DMA device

From: Lee Jones
Date: Mon Mar 30 2015 - 04:59:42 EST


On Wed, 25 Mar 2015, Holger Dengler wrote:

> From: Benedikt Spranger <b.spranger@xxxxxxxxxxxxx>
>
> The Flexcard interface design split packet receive and transmit. All
> received packets and card status information are multiplexed with a
> Flexcard specific protocol and handled through a DMA capable ringbuffer.
> The TX path has to poke each available component separate.
>
> Add a platform device for the DMA receive channel.
>
> Signed-off-by: Holger Dengler <dengler@xxxxxxxxxxxxx>
> Signed-off-by: Benedikt Spranger <b.spranger@xxxxxxxxxxxxx>
> cc: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
> cc: Lee Jones <lee.jones@xxxxxxxxxx>
> ---
> drivers/mfd/flexcard/core.c | 60 +++++++++++++++++++++++++++++++++++++++++
> drivers/mfd/flexcard/flexcard.h | 5 ++++
> 2 files changed, 65 insertions(+)
>
> diff --git a/drivers/mfd/flexcard/core.c b/drivers/mfd/flexcard/core.c
> index cd06854..39d1d4d 100644
> --- a/drivers/mfd/flexcard/core.c
> +++ b/drivers/mfd/flexcard/core.c
> @@ -52,6 +52,34 @@ static struct mfd_cell flexcard_clk_dev[] = {
> },
> };
>
> +static struct resource flexcard_dma_res[] = {
> + {
> + .name = "flexcard-dma",
> + .start = 0x500,
> + .end = 0x580,

Better to define these.

> + .flags = IORESOURCE_MEM,
> + }, {
> + .name = "flexcard-dma",
> + .start = FLEXCARD_DMA_IRQ_CBL,
> + .end = FLEXCARD_DMA_IRQ_CBL,
> + .flags = IORESOURCE_IRQ,
> + }, {
> + .name = "flexcard-dma",
> + .start = FLEXCARD_DMA_IRQ_CO,
> + .end = FLEXCARD_DMA_IRQ_CO,
> + .flags = IORESOURCE_IRQ,
> + },
> +};
> +
> +static struct mfd_cell flexcard_dma_dev[] = {
> + {
> + .id = 0,

Why do you need this for a single device?

> + .name = "flexcard-dma",
> + .num_resources = ARRAY_SIZE(flexcard_dma_res),
> + .resources = flexcard_dma_res,
> + },
> +};
> +
> irq_res(CC1CCYS);
> irq_res(CC2CCYS);
> irq_res(CC3CCYS);
> @@ -187,6 +215,32 @@ static int flexcard_clk_setup(struct flexcard_device *priv)
> &pdev->resource[0], 0, NULL);
> }
>
> +static int flexcard_add_dma(struct flexcard_device *priv)
> +{
> + struct pci_dev *pdev = priv->pdev;
> +
> + /* check for a DMA capable firmware version*/
> + if (priv->conf->fc_fw_ver.maj < DMA_MIN_FW_MAJOR)
> + goto out;
> +
> + if (priv->conf->fc_fw_ver.maj == DMA_MIN_FW_MAJOR) {
> + if (priv->conf->fc_fw_ver.min < DMA_MIN_FW_MINOR)
> + goto out;
> + if ((priv->conf->fc_fw_ver.min == DMA_MIN_FW_MINOR) &&
> + (priv->conf->fc_fw_ver.dev < DMA_MIN_FW_UPDATE))
> + goto out;
> + }
> +
> + return mfd_add_devices(&pdev->dev, 0, flexcard_dma_dev,
> + ARRAY_SIZE(flexcard_dma_dev),
> + &pdev->resource[0], 0, priv->dma_domain);
> +

Another call?

> +out:
> + dev_info(&pdev->dev, "Firmware is not DMA capable\n");
> +
> + return 0;
> +}
> +
> static int flexcard_add_uio(struct flexcard_device *priv)
> {
> struct pci_dev *pdev = priv->pdev;
> @@ -330,6 +384,12 @@ static int flexcard_probe(struct pci_dev *pdev,
> goto out_remove;
> }
>
> + ret = flexcard_add_dma(priv);
> + if (ret) {
> + dev_err(&pdev->dev, "unable to add DMA device: %d", ret);
> + goto out_remove;
> + }
> +
> ret = flexcard_add_uio(priv);
> if (ret) {
> dev_err(&pdev->dev, "unable to add irq UIO devices: %d", ret);
> diff --git a/drivers/mfd/flexcard/flexcard.h b/drivers/mfd/flexcard/flexcard.h
> index 0d05f78..ee6b773 100644
> --- a/drivers/mfd/flexcard/flexcard.h
> +++ b/drivers/mfd/flexcard/flexcard.h
> @@ -1,6 +1,11 @@
> #ifndef __FLEXCARD_H
> #define __FLEXCARD_H
>
> +/* The first FW Version supporting DMA is 6.4.0 */
> +#define DMA_MIN_FW_MAJOR 6
> +#define DMA_MIN_FW_MINOR 4
> +#define DMA_MIN_FW_UPDATE 0
> +
> int flexcard_misc_add_attrs(struct device *dev);
> void flexcard_misc_del_attrs(struct device *dev);
> int flexcard_setup_irq(struct pci_dev *pdev);

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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