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

[carl.yin@quectel.com]

From: "carl.yin" <carl.yin@quectel.com>

MHI wwan modems support download firmware to nand or emmc
by firehose protocol, process as next:
1. wwan modem normal bootup and enter EE AMSS, create mhi DIAG chan device
2. send EDL cmd via DIAG chan, then modem enter EE EDL
3. boot.c download 'firehose/prog_firehose_sdx55.mbn' via BHI interface
4. modem enter EE FP, and create mhi EDL chan device
5. user space tool download FW to modem via EDL chan by firehose protocol

Signed-off-by: carl.yin <carl.yin@quectel.com>
---
 drivers/bus/mhi/core/boot.c     |  4 +++-
 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       | 16 +++++++++++++++-
 include/linux/mhi.h             |  4 +++-
 6 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/drivers/bus/mhi/core/boot.c b/drivers/bus/mhi/core/boot.c
index 24422f5..ab39ad6 100644
--- a/drivers/bus/mhi/core/boot.c
+++ b/drivers/bus/mhi/core/boot.c
@@ -460,8 +460,10 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
 		return;
 	}
 
-	if (mhi_cntrl->ee == MHI_EE_EDL)
+	if (mhi_cntrl->ee == MHI_EE_EDL) {
+		mhi_ready_state_transition(mhi_cntrl);
 		return;
+	}
 
 	write_lock_irq(&mhi_cntrl->pm_lock);
 	mhi_cntrl->dev_state = MHI_STATE_RESET;
diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index ac4aa5c..9c2c2f3 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] = "FP",
 	[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] = "FP",
 	[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..e307b58 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -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..3c95a5d 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -563,7 +563,15 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
 	}
 
 	if (cur_state == MHI_PM_SYS_ERR_PROCESS) {
-		mhi_ready_state_transition(mhi_cntrl);
+		if (mhi_get_exec_env(mhi_cntrl) == MHI_EE_EDL
+			&& mhi_get_mhi_state(mhi_cntrl) == MHI_STATE_RESET) {
+			write_lock_irq(&mhi_cntrl->pm_lock);
+			cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_POR);
+			write_unlock_irq(&mhi_cntrl->pm_lock);
+			mhi_queue_state_transition(mhi_cntrl, DEV_ST_TRANSITION_PBL);
+		} else {
+			mhi_ready_state_transition(mhi_cntrl);
+		}
 	} else {
 		/* Move to disable state */
 		write_lock_irq(&mhi_cntrl->pm_lock);
@@ -658,6 +666,12 @@ 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 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