[PATCH v4 11/11] wifi: ath11k: Add support for MHI bandwidth scaling

[Manivannan Sadhasivam]

On Mon, Jun 09, 2025 at 04:21:32PM GMT, Krishna Chaitanya Chundru wrote:
> From: Miaoqing Pan <quic_miaoqing at quicinc.com>
> 
> Add support for MHI bandwidth scaling, which will reduce power consumption
> if WLAN operates with lower bandwidth. This feature is only enabled for
> QCA6390.
> 
> Bandwidth scaling is initiated by the endpoint firmware based upon the
> bandwidth requirements, if there is high bandwidth data endpoint requests
> for higher data rates or if there is less bandwidth they request for lower
> data rates to reduce power. Endpoint initiates this through MHI protocol.
> 
> Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-04546-QCAHSPSWPL_V1_V2_SILICONZ_IOE-1
> 
> Signed-off-by: Miaoqing Pan <quic_miaoqing at quicinc.com>
> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru at oss.qualcomm.com>
> ---
>  drivers/net/wireless/ath/ath11k/mhi.c | 41 +++++++++++++++++++++++++++++++++++
>  1 file changed, 41 insertions(+)
> 
> diff --git a/drivers/net/wireless/ath/ath11k/mhi.c b/drivers/net/wireless/ath/ath11k/mhi.c
> index acd76e9392d31192aca6776319ef0829a1c69628..f79507c7a82244f9e9d8a3ae6765df3f9432ae8c 100644
> --- a/drivers/net/wireless/ath/ath11k/mhi.c
> +++ b/drivers/net/wireless/ath/ath11k/mhi.c
> @@ -20,6 +20,7 @@
>  #define MHI_TIMEOUT_DEFAULT_MS	20000
>  #define RDDM_DUMP_SIZE	0x420000
>  #define MHI_CB_INVALID	0xff
> +#define MHI_BW_SCALE_CHAN_DB 126
>  
>  static const struct mhi_channel_config ath11k_mhi_channels_qca6390[] = {
>  	{
> @@ -73,6 +74,17 @@ static struct mhi_event_config ath11k_mhi_events_qca6390[] = {
>  		.client_managed = false,
>  		.offload_channel = false,
>  	},
> +	{
> +		.num_elements = 8,
> +		.irq_moderation_ms = 0,
> +		.irq = 1,
> +		.mode = MHI_DB_BRST_DISABLE,
> +		.data_type = MHI_ER_BW_SCALE,
> +		.priority = 2,
> +		.hardware_event = false,
> +		.client_managed = false,
> +		.offload_channel = false,
> +	},
>  };
>  
>  static const struct mhi_controller_config ath11k_mhi_config_qca6390 = {
> @@ -313,6 +325,33 @@ static void ath11k_mhi_op_write_reg(struct mhi_controller *mhi_cntrl,
>  	writel(val, addr);
>  }
>  
> +static int ath11k_mhi_op_get_misc_doorbell(struct mhi_controller *mhi_cntrl,
> +					   enum mhi_er_data_type type)
> +{
> +	if (type == MHI_ER_BW_SCALE)
> +		return MHI_BW_SCALE_CHAN_DB;
> +
> +	return -EINVAL;

-EOPNOTSUPP?

> +}
> +
> +static int ath11k_mhi_op_bw_scale(struct mhi_controller *mhi_cntrl,
> +				  struct mhi_link_info *link_info)
> +{
> +	enum pci_bus_speed speed = pci_lnkctl2_bus_speed(link_info->target_link_speed);
> +	struct ath11k_base *ab = dev_get_drvdata(mhi_cntrl->cntrl_dev);
> +	struct pci_dev *pci_dev = to_pci_dev(ab->dev);
> +	struct pci_dev *pdev;
> +
> +	if (!pci_dev)
> +		return -EINVAL;

Is it really possible?

- Mani

-- 
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