[PATCH v2] bus: mhi: core: Add support MHI EE FP for download firmware

[carl . yin]

From: "carl.yin" <carl.yin@xxxxxxxxxxx>

MHI wwan modems support download firmware to nand or emmc
by firehose protocol, process as next:
1. modem boot up and enter EE AMSS, create DIAG channels (4, 5) device
2. user space tool send EDL command via DIAG channel,
   then modem enter EE EDL
3. boot.c download 'flash programmer image' via BHI interface
4. modem enter EE FP, and create EDL channels (34, 35) device
5. user space tool download 'firmware image' to modem via EDL channels
   by firehose protocol

Signed-off-by: carl.yin <carl.yin@xxxxxxxxxxx>
---
 drivers/bus/mhi/core/init.c     |  2 ++
 drivers/bus/mhi/core/internal.h |  1 +
 drivers/bus/mhi/core/main.c     |  5 ++++-
 drivers/bus/mhi/core/pm.c       | 13 ++++++++++++-
 include/linux/mhi.h             |  4 +++-
 5 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index ac4aa5c..e34616b 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -26,6 +26,7 @@ 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",
 };
@@ -35,6 +36,7 @@ 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 4abf0cf..6ae897a 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 3950792..a1e1561 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -422,7 +422,7 @@ irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv)
 		wake_up_all(&mhi_cntrl->state_event);
 
 		/* For fatal errors, we let controller decide next step */
-		if (MHI_IN_PBL(ee))
+		if (MHI_IN_PBL(mhi_cntrl->ee))
 			mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_FATAL_ERROR);
 		else
 			mhi_pm_sys_err_handler(mhi_cntrl);
@@ -782,6 +782,9 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl,
 			case MHI_EE_SBL:
 				st = DEV_ST_TRANSITION_SBL;
 				break;
+			case MHI_EE_FP:
+				st = DEV_ST_TRANSITION_FP;
+				break;
 			case MHI_EE_WFW:
 			case MHI_EE_AMSS:
 				st = DEV_ST_TRANSITION_MISSION_MODE;
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 3de7b16..2d68812 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -658,6 +658,12 @@ 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;
@@ -1077,10 +1083,15 @@ int mhi_sync_power_up(struct mhi_controller *mhi_cntrl)
 
 	wait_event_timeout(mhi_cntrl->state_event,
 			   MHI_IN_MISSION_MODE(mhi_cntrl->ee) ||
+			   mhi_cntrl->ee == MHI_EE_FP ||
 			   MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
 			   msecs_to_jiffies(mhi_cntrl->timeout_ms));
 
-	ret = (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) ? 0 : -ETIMEDOUT;
+	if (mhi_cntrl->ee == MHI_EE_FP)
+		mhi_queue_state_transition(mhi_cntrl, DEV_ST_TRANSITION_READY);
+	else
+		ret = (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) ? 0 : -ETIMEDOUT;
+
 	if (ret)
 		mhi_power_down(mhi_cntrl, false);
 
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 6e1122c..4620af8 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -120,6 +120,7 @@ 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,
@@ -129,7 +130,8 @@ 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,
-- 
2.25.1