Re: [PATCH v1 4/7] bus: mhi: core: Add support for Flash Programmer execution environment

From: Manivannan Sadhasivam
Date: Wed Mar 31 2021 - 07:12:23 EST


On Mon, Mar 29, 2021 at 06:28:21PM -0700, Bhaumik Bhatt wrote:
> From: Carl Yin <carl.yin@xxxxxxxxxxx>
>
> MHI WWAN modems support downloading firmware to NAND or eMMC
> using Firehose protocol with process as follows:
> 1. Modem boots up, enters AMSS execution environment and the
> device later enters EDL (Emergency Download) mode through any
> mechanism host can use such as a diag command.
> 2. Modem enters SYS_ERROR, MHI host handles SYS_ERROR transition.
> 3. EDL image for device to enter 'Flash Programmer' execution
> environment is then flashed via BHI interface from host.
> 4. Modem enters MHI READY -> M0 and sends the Flash Programmer
> execution environment change to host.
> 5. Following that, EDL/FIREHOSE channels (34, 35) are made
> available from the host.
> 6. User space tool for downloading firmware image to modem over
> the EDL channels using Firehose protocol. Link to USB flashing
> tool: https://git.linaro.org/landing-teams/working/qualcomm/qdl.git/
>
> Make the necessary changes to allow for this sequence to occur and
> allow using the Flash Programmer execution environment.
>
> Signed-off-by: Carl Yin <carl.yin@xxxxxxxxxxx>
> Co-developed-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
> Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>

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

Thanks,
Mani

> ---
> drivers/bus/mhi/core/init.c | 2 ++
> drivers/bus/mhi/core/internal.h | 1 +
> drivers/bus/mhi/core/main.c | 3 +++
> drivers/bus/mhi/core/pm.c | 6 ++++++
> include/linux/mhi.h | 4 +++-
> 5 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index 706484f..ee67712 100644
> --- a/drivers/bus/mhi/core/init.c
> +++ b/drivers/bus/mhi/core/init.c
> @@ -29,6 +29,7 @@ const char * const mhi_ee_str[MHI_EE_MAX] = {
> [MHI_EE_WFW] = "WFW",
> [MHI_EE_PTHRU] = "PASS THRU",
> [MHI_EE_EDL] = "EDL",
> + [MHI_EE_FP] = "FLASH PROGRAMMER",
> [MHI_EE_DISABLE_TRANSITION] = "DISABLE",
> [MHI_EE_NOT_SUPPORTED] = "NOT SUPPORTED",
> };
> @@ -38,6 +39,7 @@ const char * const dev_state_tran_str[DEV_ST_TRANSITION_MAX] = {
> [DEV_ST_TRANSITION_READY] = "READY",
> [DEV_ST_TRANSITION_SBL] = "SBL",
> [DEV_ST_TRANSITION_MISSION_MODE] = "MISSION_MODE",
> + [DEV_ST_TRANSITION_FP] = "FLASH_PROGRAMMER",
> [DEV_ST_TRANSITION_SYS_ERR] = "SYS_ERR",
> [DEV_ST_TRANSITION_DISABLE] = "DISABLE",
> };
> diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
> index 6f37439..b1b5f2b 100644
> --- a/drivers/bus/mhi/core/internal.h
> +++ b/drivers/bus/mhi/core/internal.h
> @@ -386,6 +386,7 @@ enum dev_st_transition {
> DEV_ST_TRANSITION_READY,
> DEV_ST_TRANSITION_SBL,
> DEV_ST_TRANSITION_MISSION_MODE,
> + DEV_ST_TRANSITION_FP,
> DEV_ST_TRANSITION_SYS_ERR,
> DEV_ST_TRANSITION_DISABLE,
> DEV_ST_TRANSITION_MAX,
> diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
> index d377d07..8b68657 100644
> --- a/drivers/bus/mhi/core/main.c
> +++ b/drivers/bus/mhi/core/main.c
> @@ -831,6 +831,9 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl,
> case MHI_EE_AMSS:
> st = DEV_ST_TRANSITION_MISSION_MODE;
> break;
> + case MHI_EE_FP:
> + st = DEV_ST_TRANSITION_FP;
> + break;
> case MHI_EE_RDDM:
> mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_RDDM);
> write_lock_irq(&mhi_cntrl->pm_lock);
> diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
> index b65222e..7ac9dfe 100644
> --- a/drivers/bus/mhi/core/pm.c
> +++ b/drivers/bus/mhi/core/pm.c
> @@ -782,6 +782,12 @@ void mhi_pm_st_worker(struct work_struct *work)
> case DEV_ST_TRANSITION_MISSION_MODE:
> mhi_pm_mission_mode_transition(mhi_cntrl);
> break;
> + case DEV_ST_TRANSITION_FP:
> + write_lock_irq(&mhi_cntrl->pm_lock);
> + mhi_cntrl->ee = MHI_EE_FP;
> + write_unlock_irq(&mhi_cntrl->pm_lock);
> + mhi_create_devices(mhi_cntrl);
> + break;
> case DEV_ST_TRANSITION_READY:
> mhi_ready_state_transition(mhi_cntrl);
> break;
> diff --git a/include/linux/mhi.h b/include/linux/mhi.h
> index 8f5bf40..b16afd3 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -117,6 +117,7 @@ struct mhi_link_info {
> * @MHI_EE_WFW: WLAN firmware mode
> * @MHI_EE_PTHRU: Passthrough
> * @MHI_EE_EDL: Embedded downloader
> + * @MHI_EE_FP: Flash Programmer Environment
> */
> enum mhi_ee_type {
> MHI_EE_PBL,
> @@ -126,7 +127,8 @@ enum mhi_ee_type {
> MHI_EE_WFW,
> MHI_EE_PTHRU,
> MHI_EE_EDL,
> - MHI_EE_MAX_SUPPORTED = MHI_EE_EDL,
> + MHI_EE_FP,
> + MHI_EE_MAX_SUPPORTED = MHI_EE_FP,
> MHI_EE_DISABLE_TRANSITION, /* local EE, not related to mhi spec */
> MHI_EE_NOT_SUPPORTED,
> MHI_EE_MAX,
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>