On Mon, Apr 15, 2024 at 04:49:04PM +0800, Qiang Yu wrote:
> Some controllers may want to know the address of a certain doorbell. Hence
> add a new API where we read CHDBOFF register to get the base address of
> doorbell, so that the controller can calculate the address of the doorbell
> it wants by adding additional offset.
>
> Signed-off-by: Qiang Yu <quic_qianyu@xxxxxxxxxxx>
> ---
> drivers/bus/mhi/host/main.c | 17 +++++++++++++++++
> include/linux/mhi.h | 7 +++++++
> 2 files changed, 24 insertions(+)
>
> diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
> index 15d657a..947b5ec 100644
> --- a/drivers/bus/mhi/host/main.c
> +++ b/drivers/bus/mhi/host/main.c
> @@ -1691,3 +1691,20 @@ void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev)
> }
> }
> EXPORT_SYMBOL_GPL(mhi_unprepare_from_transfer);
> +
> +int mhi_get_channel_doorbell(struct mhi_controller *mhi_cntrl, u32 *chdb_offset)
s/mhi_get_channel_doorbell/mhi_get_channel_doorbell_offset
> +{
> + struct device *dev = &mhi_cntrl->mhi_dev->dev;
> + void __iomem *base = mhi_cntrl->regs;
> + int ret;
> +
> + /* Read channel db offset */
No need of this comment.
> + ret = mhi_read_reg(mhi_cntrl, base, CHDBOFF, chdb_offset);
> + if (ret) {
> + dev_err(dev, "Unable to read CHDBOFF register\n");
> + return -EIO;
> + }
> +
> + return 0;
> +}
Why can't you use this API in mhi_init_mmio()?
> +EXPORT_SYMBOL_GPL(mhi_get_channel_doorbell);
> diff --git a/include/linux/mhi.h b/include/linux/mhi.h
> index 8280545..1135142 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -816,4 +816,11 @@ int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
> */
> bool mhi_queue_is_full(struct mhi_device *mhi_dev, enum dma_data_direction dir);
>
> +/**
> + * mhi_get_channel_doorbell - read channel doorbell offset register to get
'Get the channel doorbell offset'
> + * channel doorbell address
> + * @mhi_cntrl: MHI controller
> + * @chdb_offset: channel doorbell address
s/channel doorbell address/Channel doorbell offset
- Mani
--
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