Merge tag 'mhi-for-v5.13' of...

Merge tag 'mhi-for-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mani/mhi into char-misc-next

Manivannan writes:

MHI changes for v5.13

core:

- Added support for Flash Programmer execution environment which allows the
  host machine (like x86) to flash the modem firmware to NAND or eMMC in the
  modem. The MHI bus will expose EDL channels (34, 35) and then the opensource
  QDL tool [1] can be used to flash the firmware from the host.
- Added an internal helper for polling the MHI registers with a retry interval.
  This helper is used now to poll for the MHI ready state in MHI STATUS
  register.
- Various fixes for issues found during the bringup of SDX24/SDX55 based Quectel
  and Telit modems.
- Updates to the Execution environment handling for proper downloading of the
  AMSS image from SBL (Secondary Bootloader) mode.
- Added support for sending STOP channel command to the MHI device and also made
  changes to the MHI core for proper handling of stop and restart.
- Fixed the runtime_pm handling in the core by forcing the device to be in wake
  mode until TX completion and allowing it to suspend for RX.
- Added sanity checks for values read from the device to avoid crash if those
  are corrupted somehow.
- Fixed warnings generated by sparse (W=2)
- Couple of kernel doc cleanups in mhi.h

pci_generic:

- Added support for runtime PM and generic PM
- Added Firehose channels for flashing the firmware
- Added support for modems such as Quectel EM1XXGR-L, SDX24, SDX65, Foxconn
  T99W175 exposing relevant channels.

[1] https://git.linaro.org/landing-teams/working/qualcomm/qdl.git

* tag 'mhi-for-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mani/mhi: (49 commits)
  bus: mhi: fix typo in comments for struct mhi_channel_config
  bus: mhi: core: Fix shadow declarations
  bus: mhi: pci_generic: Constify mhi_controller_config struct definitions
  bus: mhi: pci_generic: Introduce Foxconn T99W175 support
  bus: mhi: core: Sanity check values from remote device before use
  bus: mhi: pci_generic: Add FIREHOSE channels
  bus: mhi: pci_generic: Implement PCI shutdown callback
  bus: mhi: Improve documentation on channel transfer setup APIs
  bus: mhi: core: Remove __ prefix for MHI channel unprepare function
  bus: mhi: core: Check channel execution environment before issuing reset
  bus: mhi: core: Clear configuration from channel context during reset
  bus: mhi: core: Hold device wake for channel update commands
  bus: mhi: core: Update debug messages to use client device
  bus: mhi: core: Improvements to the channel handling state machine
  bus: mhi: core: Clear context for stopped channels from remove()
  bus: mhi: core: Allow sending the STOP channel command
  bus: mhi: pci_generic: Add SDX65 based modem support
  bus: mhi: core: Remove pre_init flag used for power purposes
  bus: mhi: pm: reduce PM state change verbosity
  bus: mhi: core: Fix MHI runtime_pm behavior
  ...

drivers/bus/mhi/core/boot.c

@@ -389,7 +389,6 @@ static void mhi_firmware_copy(struct mhi_controller *mhi_cntrl,
 void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
 {
 	const struct firmware *firmware = NULL;
-	struct image_info *image_info;
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 	const char *fw_name;
 	void *buf;
@@ -417,9 +416,9 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
 		}
 	}
 
-	/* If device is in pass through, do reset to ready state transition */
-	if (mhi_cntrl->ee == MHI_EE_PTHRU)
-		goto fw_load_ee_pthru;
+	/* wait for ready on pass through or any other execution environment */
+	if (mhi_cntrl->ee != MHI_EE_EDL && mhi_cntrl->ee != MHI_EE_PBL)
+		goto fw_load_ready_state;
 
 	fw_name = (mhi_cntrl->ee == MHI_EE_EDL) ?
 		mhi_cntrl->edl_image : mhi_cntrl->fw_image;
@@ -461,9 +460,10 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
 		goto error_fw_load;
 	}
 
-	if (mhi_cntrl->ee == MHI_EE_EDL) {
+	/* Wait for ready since EDL image was loaded */
+	if (fw_name == mhi_cntrl->edl_image) {
 		release_firmware(firmware);
-		return;
+		goto fw_load_ready_state;
 	}
 
 	write_lock_irq(&mhi_cntrl->pm_lock);
@@ -488,47 +488,45 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
 
 	release_firmware(firmware);
 
-fw_load_ee_pthru:
+fw_load_ready_state:
 	/* Transitioning into MHI RESET->READY state */
 	ret = mhi_ready_state_transition(mhi_cntrl);
-
-	if (!mhi_cntrl->fbc_download)
-		return;
-
 	if (ret) {
 		dev_err(dev, "MHI did not enter READY state\n");
 		goto error_ready_state;
 	}
 
-	/* Wait for the SBL event */
-	ret = wait_event_timeout(mhi_cntrl->state_event,
-				 mhi_cntrl->ee == MHI_EE_SBL ||
-				 MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
-				 msecs_to_jiffies(mhi_cntrl->timeout_ms));
-
-	if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
-		dev_err(dev, "MHI did not enter SBL\n");
-		goto error_ready_state;
-	}
-
-	/* Start full firmware image download */
-	image_info = mhi_cntrl->fbc_image;
-	ret = mhi_fw_load_bhie(mhi_cntrl,
-			       /* Vector table is the last entry */
-			       &image_info->mhi_buf[image_info->entries - 1]);
-	if (ret) {
-		dev_err(dev, "MHI did not load image over BHIe, ret: %d\n",
-			ret);
-		goto error_fw_load;
-	}
-
+	dev_info(dev, "Wait for device to enter SBL or Mission mode\n");
 	return;
 
 error_ready_state:
+	if (mhi_cntrl->fbc_download) {
 		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
 		mhi_cntrl->fbc_image = NULL;
+	}
 
 error_fw_load:
 	mhi_cntrl->pm_state = MHI_PM_FW_DL_ERR;
 	wake_up_all(&mhi_cntrl->state_event);
 }
+
+int mhi_download_amss_image(struct mhi_controller *mhi_cntrl)
+{
+	struct image_info *image_info = mhi_cntrl->fbc_image;
+	struct device *dev = &mhi_cntrl->mhi_dev->dev;
+	int ret;
+
+	if (!image_info)
+		return -EIO;
+
+	ret = mhi_fw_load_bhie(mhi_cntrl,
+			       /* Vector table is the last entry */
+			       &image_info->mhi_buf[image_info->entries - 1]);
+	if (ret) {
+		dev_err(dev, "MHI did not load AMSS, ret:%d\n", ret);
+		mhi_cntrl->pm_state = MHI_PM_FW_DL_ERR;
+		wake_up_all(&mhi_cntrl->state_event);
+	}
+
+	return ret;
+}

drivers/bus/mhi/core/debugfs.c

@@ -377,7 +377,7 @@ static struct dentry *mhi_debugfs_root;
 void mhi_create_debugfs(struct mhi_controller *mhi_cntrl)
 {
 	mhi_cntrl->debugfs_dentry =
-			debugfs_create_dir(dev_name(mhi_cntrl->cntrl_dev),
+			debugfs_create_dir(dev_name(&mhi_cntrl->mhi_dev->dev),
 					   mhi_debugfs_root);
 
 	debugfs_create_file("states", 0444, mhi_cntrl->debugfs_dentry,

drivers/bus/mhi/core/init.c

@@ -22,13 +22,14 @@
 static DEFINE_IDA(mhi_controller_ida);
 
 const char * const mhi_ee_str[MHI_EE_MAX] = {
-	[MHI_EE_PBL] = "PBL",
-	[MHI_EE_SBL] = "SBL",
-	[MHI_EE_AMSS] = "AMSS",
-	[MHI_EE_RDDM] = "RDDM",
-	[MHI_EE_WFW] = "WFW",
-	[MHI_EE_PTHRU] = "PASS THRU",
-	[MHI_EE_EDL] = "EDL",
+	[MHI_EE_PBL] = "PRIMARY BOOTLOADER",
+	[MHI_EE_SBL] = "SECONDARY BOOTLOADER",
+	[MHI_EE_AMSS] = "MISSION MODE",
+	[MHI_EE_RDDM] = "RAMDUMP DOWNLOAD MODE",
+	[MHI_EE_WFW] = "WLAN FIRMWARE",
+	[MHI_EE_PTHRU] = "PASS THROUGH",
+	[MHI_EE_EDL] = "EMERGENCY DOWNLOAD",
+	[MHI_EE_FP] = "FLASH PROGRAMMER",
 	[MHI_EE_DISABLE_TRANSITION] = "DISABLE",
 	[MHI_EE_NOT_SUPPORTED] = "NOT SUPPORTED",
 };
@@ -37,8 +38,9 @@ const char * const dev_state_tran_str[DEV_ST_TRANSITION_MAX] = {
 	[DEV_ST_TRANSITION_PBL] = "PBL",
 	[DEV_ST_TRANSITION_READY] = "READY",
 	[DEV_ST_TRANSITION_SBL] = "SBL",
-	[DEV_ST_TRANSITION_MISSION_MODE] = "MISSION_MODE",
-	[DEV_ST_TRANSITION_SYS_ERR] = "SYS_ERR",
+	[DEV_ST_TRANSITION_MISSION_MODE] = "MISSION MODE",
+	[DEV_ST_TRANSITION_FP] = "FLASH PROGRAMMER",
+	[DEV_ST_TRANSITION_SYS_ERR] = "SYS ERROR",
 	[DEV_ST_TRANSITION_DISABLE] = "DISABLE",
 };
 
@@ -49,24 +51,30 @@ const char * const mhi_state_str[MHI_STATE_MAX] = {
 	[MHI_STATE_M1] = "M1",
 	[MHI_STATE_M2] = "M2",
 	[MHI_STATE_M3] = "M3",
-	[MHI_STATE_M3_FAST] = "M3_FAST",
+	[MHI_STATE_M3_FAST] = "M3 FAST",
 	[MHI_STATE_BHI] = "BHI",
-	[MHI_STATE_SYS_ERR] = "SYS_ERR",
+	[MHI_STATE_SYS_ERR] = "SYS ERROR",
+};
+
+const char * const mhi_ch_state_type_str[MHI_CH_STATE_TYPE_MAX] = {
+	[MHI_CH_STATE_TYPE_RESET] = "RESET",
+	[MHI_CH_STATE_TYPE_STOP] = "STOP",
+	[MHI_CH_STATE_TYPE_START] = "START",
 };
 
 static const char * const mhi_pm_state_str[] = {
 	[MHI_PM_STATE_DISABLE] = "DISABLE",
-	[MHI_PM_STATE_POR] = "POR",
+	[MHI_PM_STATE_POR] = "POWER ON RESET",
 	[MHI_PM_STATE_M0] = "M0",
 	[MHI_PM_STATE_M2] = "M2",
 	[MHI_PM_STATE_M3_ENTER] = "M?->M3",
 	[MHI_PM_STATE_M3] = "M3",
 	[MHI_PM_STATE_M3_EXIT] = "M3->M0",
-	[MHI_PM_STATE_FW_DL_ERR] = "FW DL Error",
-	[MHI_PM_STATE_SYS_ERR_DETECT] = "SYS_ERR Detect",
-	[MHI_PM_STATE_SYS_ERR_PROCESS] = "SYS_ERR Process",
+	[MHI_PM_STATE_FW_DL_ERR] = "Firmware Download Error",
+	[MHI_PM_STATE_SYS_ERR_DETECT] = "SYS ERROR Detect",
+	[MHI_PM_STATE_SYS_ERR_PROCESS] = "SYS ERROR Process",
 	[MHI_PM_STATE_SHUTDOWN_PROCESS] = "SHUTDOWN Process",
-	[MHI_PM_STATE_LD_ERR_FATAL_DETECT] = "LD or Error Fatal Detect",
+	[MHI_PM_STATE_LD_ERR_FATAL_DETECT] = "Linkdown or Error Fatal Detect",
 };
 
 const char *to_mhi_pm_state_str(enum mhi_pm_state state)
@@ -508,8 +516,6 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
 
 	/* Setup wake db */
 	mhi_cntrl->wake_db = base + val + (8 * MHI_DEV_WAKE_DB);
-	mhi_write_reg(mhi_cntrl, mhi_cntrl->wake_db, 4, 0);
-	mhi_write_reg(mhi_cntrl, mhi_cntrl->wake_db, 0, 0);
 	mhi_cntrl->wake_set = false;
 
 	/* Setup channel db address for each channel in tre_ring */
@@ -552,6 +558,7 @@ void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
 	struct mhi_ring *buf_ring;
 	struct mhi_ring *tre_ring;
 	struct mhi_chan_ctxt *chan_ctxt;
+	u32 tmp;
 
 	buf_ring = &mhi_chan->buf_ring;
 	tre_ring = &mhi_chan->tre_ring;
@@ -565,7 +572,19 @@ void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
 	vfree(buf_ring->base);
 
 	buf_ring->base = tre_ring->base = NULL;
+	tre_ring->ctxt_wp = NULL;
 	chan_ctxt->rbase = 0;
+	chan_ctxt->rlen = 0;
+	chan_ctxt->rp = 0;
+	chan_ctxt->wp = 0;
+
+	tmp = chan_ctxt->chcfg;
+	tmp &= ~CHAN_CTX_CHSTATE_MASK;
+	tmp |= (MHI_CH_STATE_DISABLED << CHAN_CTX_CHSTATE_SHIFT);
+	chan_ctxt->chcfg = tmp;
+
+	/* Update to all cores */
+	smp_wmb();
 }
 
 int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,
@@ -863,12 +882,10 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 	u32 soc_info;
 	int ret, i;
 
-	if (!mhi_cntrl)
-		return -EINVAL;
-
-	if (!mhi_cntrl->runtime_get || !mhi_cntrl->runtime_put ||
+	if (!mhi_cntrl || !mhi_cntrl->cntrl_dev || !mhi_cntrl->regs ||
+	    !mhi_cntrl->runtime_get || !mhi_cntrl->runtime_put ||
 	    !mhi_cntrl->status_cb || !mhi_cntrl->read_reg ||
-	    !mhi_cntrl->write_reg || !mhi_cntrl->nr_irqs)
+	    !mhi_cntrl->write_reg || !mhi_cntrl->nr_irqs || !mhi_cntrl->irq)
 		return -EINVAL;
 
 	ret = parse_config(mhi_cntrl, config);
@@ -890,8 +907,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 	INIT_WORK(&mhi_cntrl->st_worker, mhi_pm_st_worker);
 	init_waitqueue_head(&mhi_cntrl->state_event);
 
-	mhi_cntrl->hiprio_wq = alloc_ordered_workqueue
-				("mhi_hiprio_wq", WQ_MEM_RECLAIM | WQ_HIGHPRI);
+	mhi_cntrl->hiprio_wq = alloc_ordered_workqueue("mhi_hiprio_wq", WQ_HIGHPRI);
 	if (!mhi_cntrl->hiprio_wq) {
 		dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate workqueue\n");
 		ret = -ENOMEM;
@@ -1083,8 +1099,6 @@ int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
 			mhi_rddm_prepare(mhi_cntrl, mhi_cntrl->rddm_image);
 	}
 
-	mhi_cntrl->pre_init = true;
-
 	mutex_unlock(&mhi_cntrl->pm_mutex);
 
 	return 0;
@@ -1115,7 +1129,6 @@ void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl)
 	}
 
 	mhi_deinit_dev_ctxt(mhi_cntrl);
-	mhi_cntrl->pre_init = false;
 }
 EXPORT_SYMBOL_GPL(mhi_unprepare_after_power_down);
 
@@ -1296,7 +1309,8 @@ static int mhi_driver_remove(struct device *dev)
 
 		mutex_lock(&mhi_chan->mutex);
 
-		if (ch_state[dir] == MHI_CH_STATE_ENABLED &&
+		if ((ch_state[dir] == MHI_CH_STATE_ENABLED ||
+		     ch_state[dir] == MHI_CH_STATE_STOP) &&
 		    !mhi_chan->offload_ch)
 			mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);
 

drivers/bus/mhi/core/internal.h

@@ -369,6 +369,18 @@ enum mhi_ch_state {
 	MHI_CH_STATE_ERROR = 0x5,
 };
 
+enum mhi_ch_state_type {
+	MHI_CH_STATE_TYPE_RESET,
+	MHI_CH_STATE_TYPE_STOP,
+	MHI_CH_STATE_TYPE_START,
+	MHI_CH_STATE_TYPE_MAX,
+};
+
+extern const char * const mhi_ch_state_type_str[MHI_CH_STATE_TYPE_MAX];
+#define TO_CH_STATE_TYPE_STR(state) (((state) >= MHI_CH_STATE_TYPE_MAX) ? \
+				     "INVALID_STATE" : \
+				     mhi_ch_state_type_str[(state)])
+
 #define MHI_INVALID_BRSTMODE(mode) (mode != MHI_DB_BRST_DISABLE && \
 				    mode != MHI_DB_BRST_ENABLE)
 
@@ -379,13 +391,15 @@ extern const char * const mhi_ee_str[MHI_EE_MAX];
 #define MHI_IN_PBL(ee) (ee == MHI_EE_PBL || ee == MHI_EE_PTHRU || \
 			ee == MHI_EE_EDL)
 
-#define MHI_IN_MISSION_MODE(ee) (ee == MHI_EE_AMSS || ee == MHI_EE_WFW)
+#define MHI_IN_MISSION_MODE(ee) (ee == MHI_EE_AMSS || ee == MHI_EE_WFW || \
+				 ee == MHI_EE_FP)
 
 enum dev_st_transition {
 	DEV_ST_TRANSITION_PBL,
 	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,
@@ -619,6 +633,7 @@ int mhi_pm_m3_transition(struct mhi_controller *mhi_cntrl);
 int __mhi_device_get_sync(struct mhi_controller *mhi_cntrl);
 int mhi_send_cmd(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
 		 enum mhi_cmd_type cmd);
+int mhi_download_amss_image(struct mhi_controller *mhi_cntrl);
 static inline bool mhi_is_active(struct mhi_controller *mhi_cntrl)
 {
 	return (mhi_cntrl->dev_state >= MHI_STATE_M0 &&
@@ -643,6 +658,9 @@ int __must_check mhi_read_reg(struct mhi_controller *mhi_cntrl,
 int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl,
 				    void __iomem *base, u32 offset, u32 mask,
 				    u32 shift, u32 *out);
+int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl,
+				    void __iomem *base, u32 offset, u32 mask,
+				    u32 shift, u32 val, u32 delayus);
 void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base,
 		   u32 offset, u32 val);
 void mhi_write_reg_field(struct mhi_controller *mhi_cntrl, void __iomem *base,

drivers/bus/mhi/core/pm.c

@@ -153,35 +153,33 @@ static void mhi_toggle_dev_wake(struct mhi_controller *mhi_cntrl)
 /* Handle device ready state transition */
 int mhi_ready_state_transition(struct mhi_controller *mhi_cntrl)
 {
-	void __iomem *base = mhi_cntrl->regs;
 	struct mhi_event *mhi_event;
 	enum mhi_pm_state cur_state;
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
-	u32 reset = 1, ready = 0;
+	u32 interval_us = 25000; /* poll register field every 25 milliseconds */
 	int ret, i;
 
-	/* Wait for RESET to be cleared and READY bit to be set by the device */
-	wait_event_timeout(mhi_cntrl->state_event,
-			   MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state) ||
-			   mhi_read_reg_field(mhi_cntrl, base, MHICTRL,
-					      MHICTRL_RESET_MASK,
-					      MHICTRL_RESET_SHIFT, &reset) ||
-			   mhi_read_reg_field(mhi_cntrl, base, MHISTATUS,
-					      MHISTATUS_READY_MASK,
-					      MHISTATUS_READY_SHIFT, &ready) ||
-			   (!reset && ready),
-			   msecs_to_jiffies(mhi_cntrl->timeout_ms));
-
 	/* Check if device entered error state */
 	if (MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state)) {
 		dev_err(dev, "Device link is not accessible\n");
 		return -EIO;
 	}
 
-	/* Timeout if device did not transition to ready state */
-	if (reset || !ready) {
-		dev_err(dev, "Device Ready timeout\n");
-		return -ETIMEDOUT;
+	/* Wait for RESET to be cleared and READY bit to be set by the device */
+	ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
+				 MHICTRL_RESET_MASK, MHICTRL_RESET_SHIFT, 0,
+				 interval_us);
+	if (ret) {
+		dev_err(dev, "Device failed to clear MHI Reset\n");
+		return ret;
+	}
+
+	ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHISTATUS,
+				 MHISTATUS_READY_MASK, MHISTATUS_READY_SHIFT, 1,
+				 interval_us);
+	if (ret) {
+		dev_err(dev, "Device failed to enter MHI Ready\n");
+		return ret;
 	}
 
 	dev_dbg(dev, "Device in READY State\n");
@@ -377,24 +375,28 @@ static int mhi_pm_mission_mode_transition(struct mhi_controller *mhi_cntrl)
 {
 	struct mhi_event *mhi_event;
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
+	enum mhi_ee_type ee = MHI_EE_MAX, current_ee = mhi_cntrl->ee;
 	int i, ret;
 
 	dev_dbg(dev, "Processing Mission Mode transition\n");
 
 	write_lock_irq(&mhi_cntrl->pm_lock);
 	if (MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state))
-		mhi_cntrl->ee = mhi_get_exec_env(mhi_cntrl);
+		ee = mhi_get_exec_env(mhi_cntrl);
 
-	if (!MHI_IN_MISSION_MODE(mhi_cntrl->ee)) {
+	if (!MHI_IN_MISSION_MODE(ee)) {
 		mhi_cntrl->pm_state = MHI_PM_LD_ERR_FATAL_DETECT;
 		write_unlock_irq(&mhi_cntrl->pm_lock);
 		wake_up_all(&mhi_cntrl->state_event);
 		return -EIO;
 	}
+	mhi_cntrl->ee = ee;
 	write_unlock_irq(&mhi_cntrl->pm_lock);
 
 	wake_up_all(&mhi_cntrl->state_event);
 
+	device_for_each_child(&mhi_cntrl->mhi_dev->dev, &current_ee,
+			      mhi_destroy_device);
 	mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_MISSION_MODE);
 
 	/* Force MHI to be in M0 state before continuing */
@@ -560,6 +562,7 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
 static void mhi_pm_sys_error_transition(struct mhi_controller *mhi_cntrl)
 {
 	enum mhi_pm_state cur_state, prev_state;
+	enum dev_st_transition next_state;
 	struct mhi_event *mhi_event;
 	struct mhi_cmd_ctxt *cmd_ctxt;
 	struct mhi_cmd *mhi_cmd;
@@ -673,7 +676,23 @@ static void mhi_pm_sys_error_transition(struct mhi_controller *mhi_cntrl)
 		er_ctxt->wp = er_ctxt->rbase;
 	}
 
-	mhi_ready_state_transition(mhi_cntrl);
+	/* Transition to next state */
+	if (MHI_IN_PBL(mhi_get_exec_env(mhi_cntrl))) {
+		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);
+		if (cur_state != MHI_PM_POR) {
+			dev_err(dev, "Error moving to state %s from %s\n",
+				to_mhi_pm_state_str(MHI_PM_POR),
+				to_mhi_pm_state_str(cur_state));
+			goto exit_sys_error_transition;
+		}
+		next_state = DEV_ST_TRANSITION_PBL;
+	} else {
+		next_state = DEV_ST_TRANSITION_READY;
+	}
+
+	mhi_queue_state_transition(mhi_cntrl, next_state);
 
 exit_sys_error_transition:
 	dev_dbg(dev, "Exiting with PM state: %s, MHI state: %s\n",
@@ -742,7 +761,6 @@ void mhi_pm_st_worker(struct work_struct *work)
 			if (MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state))
 				mhi_cntrl->ee = mhi_get_exec_env(mhi_cntrl);
 			write_unlock_irq(&mhi_cntrl->pm_lock);
-			if (MHI_IN_PBL(mhi_cntrl->ee))
 			mhi_fw_load_handler(mhi_cntrl);
 			break;
 		case DEV_ST_TRANSITION_SBL:
@@ -755,10 +773,18 @@ void mhi_pm_st_worker(struct work_struct *work)
 			 * either SBL or AMSS states
 			 */
 			mhi_create_devices(mhi_cntrl);
+			if (mhi_cntrl->fbc_download)
+				mhi_download_amss_image(mhi_cntrl);
 			break;
 		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;
@@ -822,7 +848,7 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
 		return -EBUSY;
 	}
 
-	dev_info(dev, "Allowing M3 transition\n");
+	dev_dbg(dev, "Allowing M3 transition\n");
 	new_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M3_ENTER);
 	if (new_state != MHI_PM_M3_ENTER) {
 		write_unlock_irq(&mhi_cntrl->pm_lock);
@@ -836,7 +862,7 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
 	/* Set MHI to M3 and wait for completion */
 	mhi_set_mhi_state(mhi_cntrl, MHI_STATE_M3);
 	write_unlock_irq(&mhi_cntrl->pm_lock);
-	dev_info(dev, "Wait for M3 completion\n");
+	dev_dbg(dev, "Waiting for M3 completion\n");
 
 	ret = wait_event_timeout(mhi_cntrl->state_event,
 				 mhi_cntrl->dev_state == MHI_STATE_M3 ||
@@ -870,7 +896,7 @@ int mhi_pm_resume(struct mhi_controller *mhi_cntrl)
 	enum mhi_pm_state cur_state;
 	int ret;
 
-	dev_info(dev, "Entered with PM state: %s, MHI state: %s\n",
+	dev_dbg(dev, "Entered with PM state: %s, MHI state: %s\n",
 		to_mhi_pm_state_str(mhi_cntrl->pm_state),
 		TO_MHI_STATE_STR(mhi_cntrl->dev_state));
 
@@ -880,6 +906,9 @@ int mhi_pm_resume(struct mhi_controller *mhi_cntrl)
 	if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))
 		return -EIO;
 
+	if (mhi_get_mhi_state(mhi_cntrl) != MHI_STATE_M3)
+		return -EINVAL;
+
 	/* Notify clients about exiting LPM */
 	list_for_each_entry_safe(itr, tmp, &mhi_cntrl->lpm_chans, node) {
 		mutex_lock(&itr->mutex);
@@ -1033,13 +1062,6 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 	mutex_lock(&mhi_cntrl->pm_mutex);
 	mhi_cntrl->pm_state = MHI_PM_DISABLE;
 
-	if (!mhi_cntrl->pre_init) {
-		/* Setup device context */
-		ret = mhi_init_dev_ctxt(mhi_cntrl);
-		if (ret)
-			goto error_dev_ctxt;
-	}
-
 	ret = mhi_init_irq_setup(mhi_cntrl);
 	if (ret)
 		goto error_setup_irq;
@@ -1092,7 +1114,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 							   &val) ||
 					!val,
 				msecs_to_jiffies(mhi_cntrl->timeout_ms));
-		if (ret) {
+		if (!ret) {
 			ret = -EIO;
 			dev_info(dev, "Failed to reset MHI due to syserr state\n");
 			goto error_bhi_offset;
@@ -1121,10 +1143,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 	mhi_deinit_free_irq(mhi_cntrl);
 
 error_setup_irq:
-	if (!mhi_cntrl->pre_init)
-		mhi_deinit_dev_ctxt(mhi_cntrl);
-
-error_dev_ctxt:
+	mhi_cntrl->pm_state = MHI_PM_DISABLE;
 	mutex_unlock(&mhi_cntrl->pm_mutex);
 
 	return ret;
@@ -1136,12 +1155,19 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
 	enum mhi_pm_state cur_state, transition_state;
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 
+	mutex_lock(&mhi_cntrl->pm_mutex);
+	write_lock_irq(&mhi_cntrl->pm_lock);
+	cur_state = mhi_cntrl->pm_state;
+	if (cur_state == MHI_PM_DISABLE) {
+		write_unlock_irq(&mhi_cntrl->pm_lock);
+		mutex_unlock(&mhi_cntrl->pm_mutex);
+		return; /* Already powered down */
+	}
+
 	/* If it's not a graceful shutdown, force MHI to linkdown state */
 	transition_state = (graceful) ? MHI_PM_SHUTDOWN_PROCESS :
 			   MHI_PM_LD_ERR_FATAL_DETECT;
 
-	mutex_lock(&mhi_cntrl->pm_mutex);
-	write_lock_irq(&mhi_cntrl->pm_lock);
 	cur_state = mhi_tryset_pm_state(mhi_cntrl, transition_state);
 	if (cur_state != transition_state) {
 		dev_err(dev, "Failed to move to state: %s from: %s\n",
@@ -1166,15 +1192,6 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
 	flush_work(&mhi_cntrl->st_worker);
 
 	free_irq(mhi_cntrl->irq[0], mhi_cntrl);
-
-	if (!mhi_cntrl->pre_init) {
-		/* Free all allocated resources */
-		if (mhi_cntrl->fbc_image) {
-			mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
-			mhi_cntrl->fbc_image = NULL;
-		}
-		mhi_deinit_dev_ctxt(mhi_cntrl);
-	}
 }
 EXPORT_SYMBOL_GPL(mhi_power_down);
 

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,
@@ -203,7 +205,7 @@ enum mhi_db_brst_mode {
  * @num: The number assigned to this channel
  * @num_elements: The number of elements that can be queued to this channel
  * @local_elements: The local ring length of the channel
- * @event_ring: The event rung index that services this channel
+ * @event_ring: The event ring index that services this channel
  * @dir: Direction that data may flow on this channel
  * @type: Channel type
  * @ee_mask: Execution Environment mask for this channel
@@ -296,7 +298,7 @@ struct mhi_controller_config {
  * @wake_db: MHI WAKE doorbell register address
  * @iova_start: IOMMU starting address for data (required)
  * @iova_stop: IOMMU stop address for data (required)
- * @fw_image: Firmware image name for normal booting (required)
+ * @fw_image: Firmware image name for normal booting (optional)
  * @edl_image: Firmware image name for emergency download mode (optional)
  * @rddm_size: RAM dump size that host should allocate for debugging purpose
  * @sbl_size: SBL image size downloaded through BHIe (optional)
@@ -352,7 +354,6 @@ struct mhi_controller_config {
  * @index: Index of the MHI controller instance
  * @bounce_buf: Use of bounce buffer
  * @fbc_download: MHI host needs to do complete image transfer (optional)
- * @pre_init: MHI host needs to do pre-initialization before power up
  * @wake_set: Device wakeup set flag
  * @irq_flags: irq flags passed to request_irq (optional)
  *
@@ -445,7 +446,6 @@ struct mhi_controller {
 	int index;
 	bool bounce_buf;
 	bool fbc_download;
-	bool pre_init;
 	bool wake_set;
 	unsigned long irq_flags;
 };
@@ -712,13 +712,27 @@ int mhi_device_get_sync(struct mhi_device *mhi_dev);
 void mhi_device_put(struct mhi_device *mhi_dev);
 
 /**
- * mhi_prepare_for_transfer - Setup channel for data transfer
+ * mhi_prepare_for_transfer - Setup UL and DL channels for data transfer.
+ *                            Allocate and initialize the channel context and
+ *                            also issue the START channel command to both
+ *                            channels. Channels can be started only if both
+ *                            host and device execution environments match and
+ *                            channels are in a DISABLED state.
  * @mhi_dev: Device associated with the channels
  */
 int mhi_prepare_for_transfer(struct mhi_device *mhi_dev);
 
 /**
- * mhi_unprepare_from_transfer - Unprepare the channels
+ * mhi_unprepare_from_transfer - Reset UL and DL channels for data transfer.
+ *                               Issue the RESET channel command and let the
+ *                               device clean-up the context so no incoming
+ *                               transfers are seen on the host. Free memory
+ *                               associated with the context on host. If device
+ *                               is unresponsive, only perform a host side
+ *                               clean-up. Channels can be reset only if both
+ *                               host and device execution environments match
+ *                               and channels are in an ENABLED, STOPPED or
+ *                               SUSPENDED state.
  * @mhi_dev: Device associated with the channels
  */
 void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev);