bus: mhi: core: Add support for Flash Programmer execution environment

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@quectel.com>
Co-developed-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1617067704-28850-5-git-send-email-bbhatt@codeaurora.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 706484ffe1697a09691d2288d43440e35bb9bc34..ee67712f66c0a03d7aa06cd5c577a69450f7b92a 100644 (file)
--- 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 6f37439e52472c6cd9b6ee6601aa7e15c206d7c6..b1b5f2b82393c7357da4bac3ccef67faca98825c 100644 (file)
--- 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 d377d07f269e600c2ce53e295d012f180e4a3068..8b68657c76c38fa7b3d5336d7599cd8c933ead2f 100644 (file)
--- 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 b65222eda5e616d51c82683e1a49b8ec80aa1977..7ac9dfe5489551a6a24565695386bf1d653faa4e 100644 (file)
--- 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 8f5bf409f663a01e988bbc1b27af48053a4a9954..b16afd36b4441f7e76e259dd546480d90b7d95b2 100644 (file)
--- 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,