Re: [PATCH v4 8/9] bus: mhi: core: Read and save device hardware information from BHI

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Mon, Jun 29, 2020 at 09:39:41AM -0700, Bhaumik Bhatt wrote:
> Device hardware specific information such as serial number and the OEM
> PK hash can be read using BHI and saved on host to identify the
> endpoint.
> 
> Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
> Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Thanks,
Mani

> ---
>  drivers/bus/mhi/core/boot.c | 17 ++++++++++++++++-
>  include/linux/mhi.h         |  6 ++++++
>  2 files changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/bus/mhi/core/boot.c b/drivers/bus/mhi/core/boot.c
> index 0b38014..24422f5 100644
> --- a/drivers/bus/mhi/core/boot.c
> +++ b/drivers/bus/mhi/core/boot.c
> @@ -392,13 +392,28 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
>  	void *buf;
>  	dma_addr_t dma_addr;
>  	size_t size;
> -	int ret;
> +	int i, ret;
>  
>  	if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
>  		dev_err(dev, "Device MHI is not in valid state\n");
>  		return;
>  	}
>  
> +	/* save hardware info from BHI */
> +	ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_SERIALNU,
> +			   &mhi_cntrl->serial_number);
> +	if (ret)
> +		dev_err(dev, "Could not capture serial number via BHI\n");
> +
> +	for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++) {
> +		ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_OEMPKHASH(i),
> +				   &mhi_cntrl->oem_pk_hash[i]);
> +		if (ret) {
> +			dev_err(dev, "Could not capture OEM PK HASH via BHI\n");
> +			break;
> +		}
> +	}
> +
>  	/* If device is in pass through, do reset to ready state transition */
>  	if (mhi_cntrl->ee == MHI_EE_PTHRU)
>  		goto fw_load_ee_pthru;
> diff --git a/include/linux/mhi.h b/include/linux/mhi.h
> index b1e8b4f..dad6246 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -16,6 +16,8 @@
>  #include <linux/wait.h>
>  #include <linux/workqueue.h>
>  
> +#define MHI_MAX_OEM_PK_HASH_SEGMENTS 16
> +
>  struct mhi_chan;
>  struct mhi_event;
>  struct mhi_ctxt;
> @@ -315,6 +317,8 @@ struct mhi_controller_config {
>   * @device_number: MHI controller device number
>   * @major_version: MHI controller major revision number
>   * @minor_version: MHI controller minor revision number
> + * @serial_number: MHI controller serial number obtained from BHI
> + * @oem_pk_hash: MHI controller OEM PK Hash obtained from BHI
>   * @mhi_event: MHI event ring configurations table
>   * @mhi_cmd: MHI command ring configurations table
>   * @mhi_ctxt: MHI device context, shared memory between host and device
> @@ -394,6 +398,8 @@ struct mhi_controller {
>  	u32 device_number;
>  	u32 major_version;
>  	u32 minor_version;
> +	u32 serial_number;
> +	u32 oem_pk_hash[MHI_MAX_OEM_PK_HASH_SEGMENTS];
>  
>  	struct mhi_event *mhi_event;
>  	struct mhi_cmd *mhi_cmd;
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>