[PATCH 2/7] bus: mhi: host: Add a policy to enable image transfer via BHIe in PBL

[Jeffrey Hugo]

On 1/7/2025 10:42 PM, Manivannan Sadhasivam wrote:
> On Fri, Dec 13, 2024 at 02:33:35PM -0700, Jeffrey Hugo wrote:
>> From: Matthew Leung <quic_mattleun at quicinc.com>
>>
>> Currently, mhi host only performs firmware transfer via BHI in PBL and
> 
> s/mhi/MHI here and below.

Done

> 
>> BHIe from SBL. To support BHIe transfer directly from PBL, a policy
>> needs to be added.
>>
>> With this policy, BHIe will be used to transfer firmware in PBL if the
>> mhi controller has bhie regs, sets seg_len, and does not set
> 
> s/bhie/BHIe

Done

> 
>> fbc_download. The intention is to transfer firmware using BHIe in PBL
>> without further BHIe transfers in SBL.
>>
>> Signed-off-by: Matthew Leung <quic_mattleun at quicinc.com>
>> Reviewed-by: Youssef Samir <quic_yabdulra at quicinc.com>
>> Reviewed-by: Jeffrey Hugo <quic_jhugo at quicinc.com>
>> Signed-off-by: Jeffrey Hugo <quic_jhugo at quicinc.com>
>> ---
>>   drivers/bus/mhi/host/boot.c     | 80 +++++++++++++++++++++++++++------
>>   drivers/bus/mhi/host/init.c     |  2 +-
>>   drivers/bus/mhi/host/internal.h |  8 ++++
>>   3 files changed, 75 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c
>> index e3f3c07166ad..c9ecb6427209 100644
>> --- a/drivers/bus/mhi/host/boot.c
>> +++ b/drivers/bus/mhi/host/boot.c
>> @@ -452,12 +452,62 @@ static void mhi_firmware_copy_bhie(struct mhi_controller *mhi_cntrl,
>>   	}
>>   }
>>   
>> +static enum mhi_fw_load_type mhi_fw_load_type_get(const struct mhi_controller *mhi_cntrl)
>> +{
>> +	enum mhi_fw_load_type ret = MHI_FW_LOAD_UNKNOWN;
> 
> You can directly return the enum without a local variable.

Done

> 
>> +
>> +	if (mhi_cntrl->fbc_download) {
>> +		if (mhi_cntrl->bhie && mhi_cntrl->seg_len)
> 
> I don't think this condition can fail. If 'mhi_cntrl->bhie' is NULL,
> mhi_prepare_for_power_up() will fail. So I think MHI_FW_LOAD_UNKNOWN is not
> needed.
> 
> Also, all the validation should be performed early, not while loading fw.

You are right.  That will not fail.  I've simplified this, relying on 
the existing validation.

> 
>> +			ret = MHI_FW_LOAD_FBC;
>> +	} else {
>> +		if (mhi_cntrl->bhie && mhi_cntrl->seg_len)
>> +			ret = MHI_FW_LOAD_BHIE;
>> +		else
>> +			ret = MHI_FW_LOAD_BHI;
>> +	}
>> +	return ret;
>> +}
>> +
>> +static int mhi_send_image_bhi(struct mhi_controller *mhi_cntrl, const u8 *fw_data, size_t size)
> 
> mhi_load_image_bhi?

Done

> 
>> +{
>> +	struct image_info *image;
>> +	int ret;
>> +
>> +	ret = mhi_alloc_bhi_buffer(mhi_cntrl, &image, size);
>> +	if (ret)
>> +		return ret;
>> +
>> +	mhi_firmware_copy_bhi(mhi_cntrl, fw_data, size, image);
>> +
>> +	ret = mhi_fw_load_bhi(mhi_cntrl, &image->mhi_buf[image->entries - 1]);
>> +	mhi_free_bhi_buffer(mhi_cntrl, image);
>> +
>> +	return ret;
>> +}
>> +
>> +static int mhi_send_image_bhie(struct mhi_controller *mhi_cntrl, const u8 *fw_data, size_t size)
> 
> mhi_load_image_bhie?

Done