bus: mhi: Add support for PM state transitions

This commit adds support for transitioning the MHI states as a
part of the power management operations. Helpers functions are
provided for the state transitions, which will be consumed by the
actual power management routines.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

6 files changed, 1706 insertions, 1 deletions

diff --git a/drivers/bus/mhi/core/Makefile b/drivers/bus/mhi/core/Makefile
index 2db32697c67f..a0070f9cdfcd 100644
--- a/drivers/bus/mhi/core/Makefile
+++ b/drivers/bus/mhi/core/Makefile
@@ -1,3 +1,3 @@
 obj-$(CONFIG_MHI_BUS) := mhi.o
 
-mhi-y := init.o
+mhi-y := init.o main.o pm.o
diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index b54e63459c76..91dd30eec91f 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -18,6 +18,192 @@
 #include <linux/wait.h>
 #include "internal.h"
 
+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_DISABLE_TRANSITION] = "DISABLE",
+	[MHI_EE_NOT_SUPPORTED] = "NOT SUPPORTED",
+};
+
+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",
+};
+
+const char * const mhi_state_str[MHI_STATE_MAX] = {
+	[MHI_STATE_RESET] = "RESET",
+	[MHI_STATE_READY] = "READY",
+	[MHI_STATE_M0] = "M0",
+	[MHI_STATE_M1] = "M1",
+	[MHI_STATE_M2] = "M2",
+	[MHI_STATE_M3] = "M3",
+	[MHI_STATE_M3_FAST] = "M3_FAST",
+	[MHI_STATE_BHI] = "BHI",
+	[MHI_STATE_SYS_ERR] = "SYS_ERR",
+};
+
+static const char * const mhi_pm_state_str[] = {
+	[MHI_PM_STATE_DISABLE] = "DISABLE",
+	[MHI_PM_STATE_POR] = "POR",
+	[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_SHUTDOWN_PROCESS] = "SHUTDOWN Process",
+	[MHI_PM_STATE_LD_ERR_FATAL_DETECT] = "LD or Error Fatal Detect",
+};
+
+const char *to_mhi_pm_state_str(enum mhi_pm_state state)
+{
+	int index = find_last_bit((unsigned long *)&state, 32);
+
+	if (index >= ARRAY_SIZE(mhi_pm_state_str))
+		return "Invalid State";
+
+	return mhi_pm_state_str[index];
+}
+
+int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
+{
+	u32 val;
+	int i, ret;
+	struct mhi_chan *mhi_chan;
+	struct mhi_event *mhi_event;
+	void __iomem *base = mhi_cntrl->regs;
+	struct {
+		u32 offset;
+		u32 mask;
+		u32 shift;
+		u32 val;
+	} reg_info[] = {
+		{
+			CCABAP_HIGHER, U32_MAX, 0,
+			upper_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
+		},
+		{
+			CCABAP_LOWER, U32_MAX, 0,
+			lower_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
+		},
+		{
+			ECABAP_HIGHER, U32_MAX, 0,
+			upper_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
+		},
+		{
+			ECABAP_LOWER, U32_MAX, 0,
+			lower_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
+		},
+		{
+			CRCBAP_HIGHER, U32_MAX, 0,
+			upper_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
+		},
+		{
+			CRCBAP_LOWER, U32_MAX, 0,
+			lower_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
+		},
+		{
+			MHICFG, MHICFG_NER_MASK, MHICFG_NER_SHIFT,
+			mhi_cntrl->total_ev_rings,
+		},
+		{
+			MHICFG, MHICFG_NHWER_MASK, MHICFG_NHWER_SHIFT,
+			mhi_cntrl->hw_ev_rings,
+		},
+		{
+			MHICTRLBASE_HIGHER, U32_MAX, 0,
+			upper_32_bits(mhi_cntrl->iova_start),
+		},
+		{
+			MHICTRLBASE_LOWER, U32_MAX, 0,
+			lower_32_bits(mhi_cntrl->iova_start),
+		},
+		{
+			MHIDATABASE_HIGHER, U32_MAX, 0,
+			upper_32_bits(mhi_cntrl->iova_start),
+		},
+		{
+			MHIDATABASE_LOWER, U32_MAX, 0,
+			lower_32_bits(mhi_cntrl->iova_start),
+		},
+		{
+			MHICTRLLIMIT_HIGHER, U32_MAX, 0,
+			upper_32_bits(mhi_cntrl->iova_stop),
+		},
+		{
+			MHICTRLLIMIT_LOWER, U32_MAX, 0,
+			lower_32_bits(mhi_cntrl->iova_stop),
+		},
+		{
+			MHIDATALIMIT_HIGHER, U32_MAX, 0,
+			upper_32_bits(mhi_cntrl->iova_stop),
+		},
+		{
+			MHIDATALIMIT_LOWER, U32_MAX, 0,
+			lower_32_bits(mhi_cntrl->iova_stop),
+		},
+		{ 0, 0, 0 }
+	};
+
+	dev_dbg(mhi_cntrl->dev, "Initializing MHI registers\n");
+
+	/* Read channel db offset */
+	ret = mhi_read_reg_field(mhi_cntrl, base, CHDBOFF, CHDBOFF_CHDBOFF_MASK,
+				 CHDBOFF_CHDBOFF_SHIFT, &val);
+	if (ret) {
+		dev_err(mhi_cntrl->dev, "Unable to read CHDBOFF register\n");
+		return -EIO;
+	}
+
+	/* 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 */
+	mhi_chan = mhi_cntrl->mhi_chan;
+	for (i = 0; i < mhi_cntrl->max_chan; i++, val += 8, mhi_chan++)
+		mhi_chan->tre_ring.db_addr = base + val;
+
+	/* Read event ring db offset */
+	ret = mhi_read_reg_field(mhi_cntrl, base, ERDBOFF, ERDBOFF_ERDBOFF_MASK,
+				 ERDBOFF_ERDBOFF_SHIFT, &val);
+	if (ret) {
+		dev_err(mhi_cntrl->dev, "Unable to read ERDBOFF register\n");
+		return -EIO;
+	}
+
+	/* Setup event db address for each ev_ring */
+	mhi_event = mhi_cntrl->mhi_event;
+	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, val += 8, mhi_event++) {
+		if (mhi_event->offload_ev)
+			continue;
+
+		mhi_event->ring.db_addr = base + val;
+	}
+
+	/* Setup DB register for primary CMD rings */
+	mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING].ring.db_addr = base + CRDB_LOWER;
+
+	/* Write to MMIO registers */
+	for (i = 0; reg_info[i].offset; i++)
+		mhi_write_reg_field(mhi_cntrl, base, reg_info[i].offset,
+				    reg_info[i].mask, reg_info[i].shift,
+				    reg_info[i].val);
+
+	return 0;
+}
+
 static int parse_ev_cfg(struct mhi_controller *mhi_cntrl,
 			struct mhi_controller_config *config)
 {
@@ -62,6 +248,10 @@ static int parse_ev_cfg(struct mhi_controller *mhi_cntrl,
 		if (MHI_INVALID_BRSTMODE(mhi_event->db_cfg.brstmode))
 			goto error_ev_cfg;
 
+		mhi_event->db_cfg.process_db =
+			(mhi_event->db_cfg.brstmode == MHI_DB_BRST_ENABLE) ?
+			mhi_db_brstmode : mhi_db_brstmode_disable;
+
 		mhi_event->data_type = event_cfg->data_type;
 
 		mhi_event->hw_ring = event_cfg->hardware_event;
@@ -188,6 +378,11 @@ static int parse_ch_cfg(struct mhi_controller *mhi_cntrl,
 			}
 		}
 
+		mhi_chan->db_cfg.process_db =
+				(mhi_chan->db_cfg.brstmode ==
+				MHI_DB_BRST_ENABLE) ?
+				mhi_db_brstmode : mhi_db_brstmode_disable;
+
 		mhi_chan->configured = true;
 
 		if (mhi_chan->lpm_notify)
@@ -226,6 +421,11 @@ static int parse_config(struct mhi_controller *mhi_cntrl,
 	if (!mhi_cntrl->buffer_len)
 		mhi_cntrl->buffer_len = MHI_MAX_MTU;
 
+	/* By default, host is allowed to ring DB in both M0 and M2 states */
+	mhi_cntrl->db_access = MHI_PM_M0 | MHI_PM_M2;
+	if (config->m2_no_db)
+		mhi_cntrl->db_access &= ~MHI_PM_M2;
+
 	return 0;
 
 error_ev_cfg:
@@ -262,8 +462,12 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 	}
 
 	INIT_LIST_HEAD(&mhi_cntrl->transition_list);
+	mutex_init(&mhi_cntrl->pm_mutex);
+	rwlock_init(&mhi_cntrl->pm_lock);
 	spin_lock_init(&mhi_cntrl->transition_lock);
 	spin_lock_init(&mhi_cntrl->wlock);
+	INIT_WORK(&mhi_cntrl->st_worker, mhi_pm_st_worker);
+	INIT_WORK(&mhi_cntrl->syserr_worker, mhi_pm_sys_err_worker);
 	init_waitqueue_head(&mhi_cntrl->state_event);
 
 	mhi_cmd = mhi_cntrl->mhi_cmd;
diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
index 0b369f770969..3a9309446f23 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h
@@ -9,6 +9,319 @@
 
 extern struct bus_type mhi_bus_type;
 
+/* MHI MMIO register mapping */
+#define PCI_INVALID_READ(val) (val == U32_MAX)
+
+#define MHIREGLEN (0x0)
+#define MHIREGLEN_MHIREGLEN_MASK (0xFFFFFFFF)
+#define MHIREGLEN_MHIREGLEN_SHIFT (0)
+
+#define MHIVER (0x8)
+#define MHIVER_MHIVER_MASK (0xFFFFFFFF)
+#define MHIVER_MHIVER_SHIFT (0)
+
+#define MHICFG (0x10)
+#define MHICFG_NHWER_MASK (0xFF000000)
+#define MHICFG_NHWER_SHIFT (24)
+#define MHICFG_NER_MASK (0xFF0000)
+#define MHICFG_NER_SHIFT (16)
+#define MHICFG_NHWCH_MASK (0xFF00)
+#define MHICFG_NHWCH_SHIFT (8)
+#define MHICFG_NCH_MASK (0xFF)
+#define MHICFG_NCH_SHIFT (0)
+
+#define CHDBOFF (0x18)
+#define CHDBOFF_CHDBOFF_MASK (0xFFFFFFFF)
+#define CHDBOFF_CHDBOFF_SHIFT (0)
+
+#define ERDBOFF (0x20)
+#define ERDBOFF_ERDBOFF_MASK (0xFFFFFFFF)
+#define ERDBOFF_ERDBOFF_SHIFT (0)
+
+#define BHIOFF (0x28)
+#define BHIOFF_BHIOFF_MASK (0xFFFFFFFF)
+#define BHIOFF_BHIOFF_SHIFT (0)
+
+#define BHIEOFF (0x2C)
+#define BHIEOFF_BHIEOFF_MASK (0xFFFFFFFF)
+#define BHIEOFF_BHIEOFF_SHIFT (0)
+
+#define DEBUGOFF (0x30)
+#define DEBUGOFF_DEBUGOFF_MASK (0xFFFFFFFF)
+#define DEBUGOFF_DEBUGOFF_SHIFT (0)
+
+#define MHICTRL (0x38)
+#define MHICTRL_MHISTATE_MASK (0x0000FF00)
+#define MHICTRL_MHISTATE_SHIFT (8)
+#define MHICTRL_RESET_MASK (0x2)
+#define MHICTRL_RESET_SHIFT (1)
+
+#define MHISTATUS (0x48)
+#define MHISTATUS_MHISTATE_MASK (0x0000FF00)
+#define MHISTATUS_MHISTATE_SHIFT (8)
+#define MHISTATUS_SYSERR_MASK (0x4)
+#define MHISTATUS_SYSERR_SHIFT (2)
+#define MHISTATUS_READY_MASK (0x1)
+#define MHISTATUS_READY_SHIFT (0)
+
+#define CCABAP_LOWER (0x58)
+#define CCABAP_LOWER_CCABAP_LOWER_MASK (0xFFFFFFFF)
+#define CCABAP_LOWER_CCABAP_LOWER_SHIFT (0)
+
+#define CCABAP_HIGHER (0x5C)
+#define CCABAP_HIGHER_CCABAP_HIGHER_MASK (0xFFFFFFFF)
+#define CCABAP_HIGHER_CCABAP_HIGHER_SHIFT (0)
+
+#define ECABAP_LOWER (0x60)
+#define ECABAP_LOWER_ECABAP_LOWER_MASK (0xFFFFFFFF)
+#define ECABAP_LOWER_ECABAP_LOWER_SHIFT (0)
+
+#define ECABAP_HIGHER (0x64)
+#define ECABAP_HIGHER_ECABAP_HIGHER_MASK (0xFFFFFFFF)
+#define ECABAP_HIGHER_ECABAP_HIGHER_SHIFT (0)
+
+#define CRCBAP_LOWER (0x68)
+#define CRCBAP_LOWER_CRCBAP_LOWER_MASK (0xFFFFFFFF)
+#define CRCBAP_LOWER_CRCBAP_LOWER_SHIFT (0)
+
+#define CRCBAP_HIGHER (0x6C)
+#define CRCBAP_HIGHER_CRCBAP_HIGHER_MASK (0xFFFFFFFF)
+#define CRCBAP_HIGHER_CRCBAP_HIGHER_SHIFT (0)
+
+#define CRDB_LOWER (0x70)
+#define CRDB_LOWER_CRDB_LOWER_MASK (0xFFFFFFFF)
+#define CRDB_LOWER_CRDB_LOWER_SHIFT (0)
+
+#define CRDB_HIGHER (0x74)
+#define CRDB_HIGHER_CRDB_HIGHER_MASK (0xFFFFFFFF)
+#define CRDB_HIGHER_CRDB_HIGHER_SHIFT (0)
+
+#define MHICTRLBASE_LOWER (0x80)
+#define MHICTRLBASE_LOWER_MHICTRLBASE_LOWER_MASK (0xFFFFFFFF)
+#define MHICTRLBASE_LOWER_MHICTRLBASE_LOWER_SHIFT (0)
+
+#define MHICTRLBASE_HIGHER (0x84)
+#define MHICTRLBASE_HIGHER_MHICTRLBASE_HIGHER_MASK (0xFFFFFFFF)
+#define MHICTRLBASE_HIGHER_MHICTRLBASE_HIGHER_SHIFT (0)
+
+#define MHICTRLLIMIT_LOWER (0x88)
+#define MHICTRLLIMIT_LOWER_MHICTRLLIMIT_LOWER_MASK (0xFFFFFFFF)
+#define MHICTRLLIMIT_LOWER_MHICTRLLIMIT_LOWER_SHIFT (0)
+
+#define MHICTRLLIMIT_HIGHER (0x8C)
+#define MHICTRLLIMIT_HIGHER_MHICTRLLIMIT_HIGHER_MASK (0xFFFFFFFF)
+#define MHICTRLLIMIT_HIGHER_MHICTRLLIMIT_HIGHER_SHIFT (0)
+
+#define MHIDATABASE_LOWER (0x98)
+#define MHIDATABASE_LOWER_MHIDATABASE_LOWER_MASK (0xFFFFFFFF)
+#define MHIDATABASE_LOWER_MHIDATABASE_LOWER_SHIFT (0)
+
+#define MHIDATABASE_HIGHER (0x9C)
+#define MHIDATABASE_HIGHER_MHIDATABASE_HIGHER_MASK (0xFFFFFFFF)
+#define MHIDATABASE_HIGHER_MHIDATABASE_HIGHER_SHIFT (0)
+
+#define MHIDATALIMIT_LOWER (0xA0)
+#define MHIDATALIMIT_LOWER_MHIDATALIMIT_LOWER_MASK (0xFFFFFFFF)
+#define MHIDATALIMIT_LOWER_MHIDATALIMIT_LOWER_SHIFT (0)
+
+#define MHIDATALIMIT_HIGHER (0xA4)
+#define MHIDATALIMIT_HIGHER_MHIDATALIMIT_HIGHER_MASK (0xFFFFFFFF)
+#define MHIDATALIMIT_HIGHER_MHIDATALIMIT_HIGHER_SHIFT (0)
+
+/* Host request register */
+#define MHI_SOC_RESET_REQ_OFFSET (0xB0)
+#define MHI_SOC_RESET_REQ BIT(0)
+
+/* MHI BHI offfsets */
+#define BHI_BHIVERSION_MINOR (0x00)
+#define BHI_BHIVERSION_MAJOR (0x04)
+#define BHI_IMGADDR_LOW (0x08)
+#define BHI_IMGADDR_HIGH (0x0C)
+#define BHI_IMGSIZE (0x10)
+#define BHI_RSVD1 (0x14)
+#define BHI_IMGTXDB (0x18)
+#define BHI_TXDB_SEQNUM_BMSK (0x3FFFFFFF)
+#define BHI_TXDB_SEQNUM_SHFT (0)
+#define BHI_RSVD2 (0x1C)
+#define BHI_INTVEC (0x20)
+#define BHI_RSVD3 (0x24)
+#define BHI_EXECENV (0x28)
+#define BHI_STATUS (0x2C)
+#define BHI_ERRCODE (0x30)
+#define BHI_ERRDBG1 (0x34)
+#define BHI_ERRDBG2 (0x38)
+#define BHI_ERRDBG3 (0x3C)
+#define BHI_SERIALNU (0x40)
+#define BHI_SBLANTIROLLVER (0x44)
+#define BHI_NUMSEG (0x48)
+#define BHI_MSMHWID(n) (0x4C + (0x4 * n))
+#define BHI_OEMPKHASH(n) (0x64 + (0x4 * n))
+#define BHI_RSVD5 (0xC4)
+#define BHI_STATUS_MASK (0xC0000000)
+#define BHI_STATUS_SHIFT (30)
+#define BHI_STATUS_ERROR (3)
+#define BHI_STATUS_SUCCESS (2)
+#define BHI_STATUS_RESET (0)
+
+/* MHI BHIE offsets */
+#define BHIE_MSMSOCID_OFFS (0x0000)
+#define BHIE_TXVECADDR_LOW_OFFS (0x002C)
+#define BHIE_TXVECADDR_HIGH_OFFS (0x0030)
+#define BHIE_TXVECSIZE_OFFS (0x0034)
+#define BHIE_TXVECDB_OFFS (0x003C)
+#define BHIE_TXVECDB_SEQNUM_BMSK (0x3FFFFFFF)
+#define BHIE_TXVECDB_SEQNUM_SHFT (0)
+#define BHIE_TXVECSTATUS_OFFS (0x0044)
+#define BHIE_TXVECSTATUS_SEQNUM_BMSK (0x3FFFFFFF)
+#define BHIE_TXVECSTATUS_SEQNUM_SHFT (0)
+#define BHIE_TXVECSTATUS_STATUS_BMSK (0xC0000000)
+#define BHIE_TXVECSTATUS_STATUS_SHFT (30)
+#define BHIE_TXVECSTATUS_STATUS_RESET (0x00)
+#define BHIE_TXVECSTATUS_STATUS_XFER_COMPL (0x02)
+#define BHIE_TXVECSTATUS_STATUS_ERROR (0x03)
+#define BHIE_RXVECADDR_LOW_OFFS (0x0060)
+#define BHIE_RXVECADDR_HIGH_OFFS (0x0064)
+#define BHIE_RXVECSIZE_OFFS (0x0068)
+#define BHIE_RXVECDB_OFFS (0x0070)
+#define BHIE_RXVECDB_SEQNUM_BMSK (0x3FFFFFFF)
+#define BHIE_RXVECDB_SEQNUM_SHFT (0)
+#define BHIE_RXVECSTATUS_OFFS (0x0078)
+#define BHIE_RXVECSTATUS_SEQNUM_BMSK (0x3FFFFFFF)
+#define BHIE_RXVECSTATUS_SEQNUM_SHFT (0)
+#define BHIE_RXVECSTATUS_STATUS_BMSK (0xC0000000)
+#define BHIE_RXVECSTATUS_STATUS_SHFT (30)
+#define BHIE_RXVECSTATUS_STATUS_RESET (0x00)
+#define BHIE_RXVECSTATUS_STATUS_XFER_COMPL (0x02)
+#define BHIE_RXVECSTATUS_STATUS_ERROR (0x03)
+
+struct mhi_event_ctxt {
+	u32 reserved : 8;
+	u32 intmodc : 8;
+	u32 intmodt : 16;
+	u32 ertype;
+	u32 msivec;
+
+	u64 rbase __packed __aligned(4);
+	u64 rlen __packed __aligned(4);
+	u64 rp __packed __aligned(4);
+	u64 wp __packed __aligned(4);
+};
+
+struct mhi_chan_ctxt {
+	u32 chstate : 8;
+	u32 brstmode : 2;
+	u32 pollcfg : 6;
+	u32 reserved : 16;
+	u32 chtype;
+	u32 erindex;
+
+	u64 rbase __packed __aligned(4);
+	u64 rlen __packed __aligned(4);
+	u64 rp __packed __aligned(4);
+	u64 wp __packed __aligned(4);
+};
+
+struct mhi_cmd_ctxt {
+	u32 reserved0;
+	u32 reserved1;
+	u32 reserved2;
+
+	u64 rbase __packed __aligned(4);
+	u64 rlen __packed __aligned(4);
+	u64 rp __packed __aligned(4);
+	u64 wp __packed __aligned(4);
+};
+
+struct mhi_tre {
+	u64 ptr;
+	u32 dword[2];
+};
+
+struct bhi_vec_entry {
+	u64 dma_addr;
+	u64 size;
+};
+
+enum mhi_cmd_type {
+	MHI_CMD_NOP = 1,
+	MHI_CMD_RESET_CHAN = 16,
+	MHI_CMD_STOP_CHAN = 17,
+	MHI_CMD_START_CHAN = 18,
+};
+
+/* No operation command */
+#define MHI_TRE_CMD_NOOP_PTR (0)
+#define MHI_TRE_CMD_NOOP_DWORD0 (0)
+#define MHI_TRE_CMD_NOOP_DWORD1 (MHI_CMD_NOP << 16)
+
+/* Channel reset command */
+#define MHI_TRE_CMD_RESET_PTR (0)
+#define MHI_TRE_CMD_RESET_DWORD0 (0)
+#define MHI_TRE_CMD_RESET_DWORD1(chid) ((chid << 24) | \
+					(MHI_CMD_RESET_CHAN << 16))
+
+/* Channel stop command */
+#define MHI_TRE_CMD_STOP_PTR (0)
+#define MHI_TRE_CMD_STOP_DWORD0 (0)
+#define MHI_TRE_CMD_STOP_DWORD1(chid) ((chid << 24) | \
+				       (MHI_CMD_STOP_CHAN << 16))
+
+/* Channel start command */
+#define MHI_TRE_CMD_START_PTR (0)
+#define MHI_TRE_CMD_START_DWORD0 (0)
+#define MHI_TRE_CMD_START_DWORD1(chid) ((chid << 24) | \
+					(MHI_CMD_START_CHAN << 16))
+
+#define MHI_TRE_GET_CMD_CHID(tre) (((tre)->dword[1] >> 24) & 0xFF)
+#define MHI_TRE_GET_CMD_TYPE(tre) (((tre)->dword[1] >> 16) & 0xFF)
+
+/* Event descriptor macros */
+#define MHI_TRE_EV_PTR(ptr) (ptr)
+#define MHI_TRE_EV_DWORD0(code, len) ((code << 24) | len)
+#define MHI_TRE_EV_DWORD1(chid, type) ((chid << 24) | (type << 16))
+#define MHI_TRE_GET_EV_PTR(tre) ((tre)->ptr)
+#define MHI_TRE_GET_EV_CODE(tre) (((tre)->dword[0] >> 24) & 0xFF)
+#define MHI_TRE_GET_EV_LEN(tre) ((tre)->dword[0] & 0xFFFF)
+#define MHI_TRE_GET_EV_CHID(tre) (((tre)->dword[1] >> 24) & 0xFF)
+#define MHI_TRE_GET_EV_TYPE(tre) (((tre)->dword[1] >> 16) & 0xFF)
+#define MHI_TRE_GET_EV_STATE(tre) (((tre)->dword[0] >> 24) & 0xFF)
+#define MHI_TRE_GET_EV_EXECENV(tre) (((tre)->dword[0] >> 24) & 0xFF)
+#define MHI_TRE_GET_EV_SEQ(tre) ((tre)->dword[0])
+#define MHI_TRE_GET_EV_TIME(tre) ((tre)->ptr)
+#define MHI_TRE_GET_EV_COOKIE(tre) lower_32_bits((tre)->ptr)
+#define MHI_TRE_GET_EV_VEID(tre) (((tre)->dword[0] >> 16) & 0xFF)
+#define MHI_TRE_GET_EV_LINKSPEED(tre) (((tre)->dword[1] >> 24) & 0xFF)
+#define MHI_TRE_GET_EV_LINKWIDTH(tre) ((tre)->dword[0] & 0xFF)
+
+/* Transfer descriptor macros */
+#define MHI_TRE_DATA_PTR(ptr) (ptr)
+#define MHI_TRE_DATA_DWORD0(len) (len & MHI_MAX_MTU)
+#define MHI_TRE_DATA_DWORD1(bei, ieot, ieob, chain) ((2 << 16) | (bei << 10) \
+	| (ieot << 9) | (ieob << 8) | chain)
+
+/* RSC transfer descriptor macros */
+#define MHI_RSCTRE_DATA_PTR(ptr, len) (((u64)len << 48) | ptr)
+#define MHI_RSCTRE_DATA_DWORD0(cookie) (cookie)
+#define MHI_RSCTRE_DATA_DWORD1 (MHI_PKT_TYPE_COALESCING << 16)
+
+enum mhi_pkt_type {
+	MHI_PKT_TYPE_INVALID = 0x0,
+	MHI_PKT_TYPE_NOOP_CMD = 0x1,
+	MHI_PKT_TYPE_TRANSFER = 0x2,
+	MHI_PKT_TYPE_COALESCING = 0x8,
+	MHI_PKT_TYPE_RESET_CHAN_CMD = 0x10,
+	MHI_PKT_TYPE_STOP_CHAN_CMD = 0x11,
+	MHI_PKT_TYPE_START_CHAN_CMD = 0x12,
+	MHI_PKT_TYPE_STATE_CHANGE_EVENT = 0x20,
+	MHI_PKT_TYPE_CMD_COMPLETION_EVENT = 0x21,
+	MHI_PKT_TYPE_TX_EVENT = 0x22,
+	MHI_PKT_TYPE_RSC_TX_EVENT = 0x28,
+	MHI_PKT_TYPE_EE_EVENT = 0x40,
+	MHI_PKT_TYPE_TSYNC_EVENT = 0x48,
+	MHI_PKT_TYPE_BW_REQ_EVENT = 0x50,
+	MHI_PKT_TYPE_STALE_EVENT, /* internal event */
+};
+
 /* MHI transfer completion events */
 enum mhi_ev_ccs {
 	MHI_EV_CC_INVALID = 0x0,
@@ -34,9 +347,85 @@ enum mhi_ch_state {
 #define MHI_INVALID_BRSTMODE(mode) (mode != MHI_DB_BRST_DISABLE && \
 				    mode != MHI_DB_BRST_ENABLE)
 
+extern const char * const mhi_ee_str[MHI_EE_MAX];
+#define TO_MHI_EXEC_STR(ee) (((ee) >= MHI_EE_MAX) ? \
+			     "INVALID_EE" : mhi_ee_str[ee])
+
+#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)
+
+enum dev_st_transition {
+	DEV_ST_TRANSITION_PBL,
+	DEV_ST_TRANSITION_READY,
+	DEV_ST_TRANSITION_SBL,
+	DEV_ST_TRANSITION_MISSION_MODE,
+	DEV_ST_TRANSITION_MAX,
+};
+
+extern const char * const dev_state_tran_str[DEV_ST_TRANSITION_MAX];
+#define TO_DEV_STATE_TRANS_STR(state) (((state) >= DEV_ST_TRANSITION_MAX) ? \
+				"INVALID_STATE" : dev_state_tran_str[state])
+
+extern const char * const mhi_state_str[MHI_STATE_MAX];
+#define TO_MHI_STATE_STR(state) ((state >= MHI_STATE_MAX || \
+				  !mhi_state_str[state]) ? \
+				"INVALID_STATE" : mhi_state_str[state])
+
+/* internal power states */
+enum mhi_pm_state {
+	MHI_PM_STATE_DISABLE,
+	MHI_PM_STATE_POR,
+	MHI_PM_STATE_M0,
+	MHI_PM_STATE_M2,
+	MHI_PM_STATE_M3_ENTER,
+	MHI_PM_STATE_M3,
+	MHI_PM_STATE_M3_EXIT,
+	MHI_PM_STATE_FW_DL_ERR,
+	MHI_PM_STATE_SYS_ERR_DETECT,
+	MHI_PM_STATE_SYS_ERR_PROCESS,
+	MHI_PM_STATE_SHUTDOWN_PROCESS,
+	MHI_PM_STATE_LD_ERR_FATAL_DETECT,
+	MHI_PM_STATE_MAX
+};
+
+#define MHI_PM_DISABLE			BIT(0)
+#define MHI_PM_POR			BIT(1)
+#define MHI_PM_M0			BIT(2)
+#define MHI_PM_M2			BIT(3)
+#define MHI_PM_M3_ENTER			BIT(4)
+#define MHI_PM_M3			BIT(5)
+#define MHI_PM_M3_EXIT			BIT(6)
+/* firmware download failure state */
+#define MHI_PM_FW_DL_ERR		BIT(7)
+#define MHI_PM_SYS_ERR_DETECT		BIT(8)
+#define MHI_PM_SYS_ERR_PROCESS		BIT(9)
+#define MHI_PM_SHUTDOWN_PROCESS		BIT(10)
+/* link not accessible */
+#define MHI_PM_LD_ERR_FATAL_DETECT	BIT(11)
+
+#define MHI_REG_ACCESS_VALID(pm_state) ((pm_state & (MHI_PM_POR | MHI_PM_M0 | \
+		MHI_PM_M2 | MHI_PM_M3_ENTER | MHI_PM_M3_EXIT | \
+		MHI_PM_SYS_ERR_DETECT | MHI_PM_SYS_ERR_PROCESS | \
+		MHI_PM_SHUTDOWN_PROCESS | MHI_PM_FW_DL_ERR)))
+#define MHI_PM_IN_ERROR_STATE(pm_state) (pm_state >= MHI_PM_FW_DL_ERR)
+#define MHI_PM_IN_FATAL_STATE(pm_state) (pm_state == MHI_PM_LD_ERR_FATAL_DETECT)
+#define MHI_DB_ACCESS_VALID(mhi_cntrl) (mhi_cntrl->pm_state & \
+					mhi_cntrl->db_access)
+#define MHI_WAKE_DB_CLEAR_VALID(pm_state) (pm_state & (MHI_PM_M0 | \
+						MHI_PM_M2 | MHI_PM_M3_EXIT))
+#define MHI_WAKE_DB_SET_VALID(pm_state) (pm_state & MHI_PM_M2)
+#define MHI_WAKE_DB_FORCE_SET_VALID(pm_state) MHI_WAKE_DB_CLEAR_VALID(pm_state)
+#define MHI_EVENT_ACCESS_INVALID(pm_state) (pm_state == MHI_PM_DISABLE || \
+					    MHI_PM_IN_ERROR_STATE(pm_state))
+#define MHI_PM_IN_SUSPEND_STATE(pm_state) (pm_state & \
+					   (MHI_PM_M3_ENTER | MHI_PM_M3))
+
 #define NR_OF_CMD_RINGS			1
 #define CMD_EL_PER_RING			128
 #define PRIMARY_CMD_RING		0
+#define MHI_DEV_WAKE_DB			127
 #define MHI_MAX_MTU			0xffff
 
 enum mhi_er_type {
@@ -65,6 +454,25 @@ struct db_cfg {
 			   dma_addr_t db_val);
 };
 
+struct mhi_pm_transitions {
+	enum mhi_pm_state from_state;
+	u32 to_states;
+};
+
+struct state_transition {
+	struct list_head node;
+	enum dev_st_transition state;
+};
+
+struct mhi_ctxt {
+	struct mhi_event_ctxt *er_ctxt;
+	struct mhi_chan_ctxt *chan_ctxt;
+	struct mhi_cmd_ctxt *cmd_ctxt;
+	dma_addr_t er_ctxt_addr;
+	dma_addr_t chan_ctxt_addr;
+	dma_addr_t cmd_ctxt_addr;
+};
+
 struct mhi_ring {
 	dma_addr_t dma_handle;
 	dma_addr_t iommu_base;
@@ -140,6 +548,7 @@ struct mhi_chan {
 	bool offload_ch;
 	bool pre_alloc;
 	bool auto_start;
+	bool wake_capable;
 	/* functions that generate the transfer ring elements */
 	int (*gen_tre)(struct mhi_controller *mhi_cntrl,
 		       struct mhi_chan *mhi_chan, void *buf, void *cb,
@@ -168,4 +577,76 @@ static inline void mhi_dealloc_device(struct mhi_controller *mhi_cntrl,
 int mhi_destroy_device(struct device *dev, void *data);
 void mhi_create_devices(struct mhi_controller *mhi_cntrl);
 
+/* Power management APIs */
+enum mhi_pm_state __must_check mhi_tryset_pm_state(
+					struct mhi_controller *mhi_cntrl,
+					enum mhi_pm_state state);
+const char *to_mhi_pm_state_str(enum mhi_pm_state state);
+void mhi_reset_chan(struct mhi_controller *mhi_cntrl,
+		    struct mhi_chan *mhi_chan);
+enum mhi_ee_type mhi_get_exec_env(struct mhi_controller *mhi_cntrl);
+int mhi_queue_state_transition(struct mhi_controller *mhi_cntrl,
+			       enum dev_st_transition state);
+void mhi_pm_st_worker(struct work_struct *work);
+void mhi_pm_sys_err_worker(struct work_struct *work);
+int mhi_ready_state_transition(struct mhi_controller *mhi_cntrl);
+void mhi_ctrl_ev_task(unsigned long data);
+int mhi_pm_m0_transition(struct mhi_controller *mhi_cntrl);
+void mhi_pm_m1_transition(struct mhi_controller *mhi_cntrl);
+int mhi_pm_m3_transition(struct mhi_controller *mhi_cntrl);
+void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason);
+int mhi_send_cmd(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
+		 enum mhi_cmd_type cmd);
+int __mhi_device_get_sync(struct mhi_controller *mhi_cntrl);
+
+/* Register access methods */
+void mhi_db_brstmode(struct mhi_controller *mhi_cntrl, struct db_cfg *db_cfg,
+		     void __iomem *db_addr, dma_addr_t db_val);
+void mhi_db_brstmode_disable(struct mhi_controller *mhi_cntrl,
+			     struct db_cfg *db_mode, void __iomem *db_addr,
+			     dma_addr_t db_val);
+int __must_check mhi_read_reg(struct mhi_controller *mhi_cntrl,
+			      void __iomem *base, u32 offset, u32 *out);
+int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl,
+				    void __iomem *base, u32 offset, u32 mask,
+				    u32 shift, u32 *out);
+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,
+			 u32 offset, u32 mask, u32 shift, u32 val);
+void mhi_ring_er_db(struct mhi_event *mhi_event);
+void mhi_write_db(struct mhi_controller *mhi_cntrl, void __iomem *db_addr,
+		  dma_addr_t db_val);
+void mhi_ring_cmd_db(struct mhi_controller *mhi_cntrl, struct mhi_cmd *mhi_cmd);
+void mhi_ring_chan_db(struct mhi_controller *mhi_cntrl,
+		      struct mhi_chan *mhi_chan);
+int mhi_get_capability_offset(struct mhi_controller *mhi_cntrl, u32 capability,
+			      u32 *offset);
+
+/* Memory allocation methods */
+static inline void *mhi_alloc_coherent(struct mhi_controller *mhi_cntrl,
+				       size_t size,
+				       dma_addr_t *dma_handle,
+				       gfp_t gfp)
+{
+	void *buf = dma_alloc_coherent(mhi_cntrl->dev, size, dma_handle, gfp);
+
+	if (buf)
+		atomic_add(size, &mhi_cntrl->alloc_size);
+
+	return buf;
+}
+
+static inline void mhi_free_coherent(struct mhi_controller *mhi_cntrl,
+				     size_t size,
+				     void *vaddr,
+				     dma_addr_t dma_handle)
+{
+	atomic_sub(size, &mhi_cntrl->alloc_size);
+	dma_free_coherent(mhi_cntrl->dev, size, vaddr, dma_handle);
+}
+
+/* Initialization methods */
+int mhi_init_mmio(struct mhi_controller *mhi_cntrl);
+
 #endif /* _MHI_INT_H */
diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
new file mode 100644
index 000000000000..347bbff7a35e
--- /dev/null
+++ b/drivers/bus/mhi/core/main.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
+ *
+ */
+
+#define dev_fmt(fmt) "MHI: " fmt
+
+#include <linux/device.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/mhi.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include "internal.h"
+
+int __must_check mhi_read_reg(struct mhi_controller *mhi_cntrl,
+			      void __iomem *base, u32 offset, u32 *out)
+{
+	u32 tmp = le32_to_cpu(readl_relaxed(base + offset));
+
+	/* If there is any unexpected value, query the link status */
+	if (PCI_INVALID_READ(tmp) &&
+	    mhi_cntrl->link_status(mhi_cntrl, mhi_cntrl->priv_data))
+		return -EIO;
+
+	*out = tmp;
+
+	return 0;
+}
+
+int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl,
+				    void __iomem *base, u32 offset,
+				    u32 mask, u32 shift, u32 *out)
+{
+	u32 tmp;
+	int ret;
+
+	ret = mhi_read_reg(mhi_cntrl, base, offset, &tmp);
+	if (ret)
+		return ret;
+
+	*out = (tmp & mask) >> shift;
+
+	return 0;
+}
+
+void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base,
+		   u32 offset, u32 val)
+{
+	writel_relaxed(val, base + offset);
+}
+
+void mhi_write_reg_field(struct mhi_controller *mhi_cntrl, void __iomem *base,
+			 u32 offset, u32 mask, u32 shift, u32 val)
+{
+	int ret;
+	u32 tmp;
+
+	ret = mhi_read_reg(mhi_cntrl, base, offset, &tmp);
+	if (ret)
+		return;
+
+	tmp &= ~mask;
+	tmp |= (val << shift);
+	mhi_write_reg(mhi_cntrl, base, offset, tmp);
+}
+
+void mhi_write_db(struct mhi_controller *mhi_cntrl, void __iomem *db_addr,
+		  dma_addr_t db_val)
+{
+	mhi_write_reg(mhi_cntrl, db_addr, 4, upper_32_bits(db_val));
+	mhi_write_reg(mhi_cntrl, db_addr, 0, lower_32_bits(db_val));
+}
+
+void mhi_db_brstmode(struct mhi_controller *mhi_cntrl,
+		     struct db_cfg *db_cfg,
+		     void __iomem *db_addr,
+		     dma_addr_t db_val)
+{
+	if (db_cfg->db_mode) {
+		db_cfg->db_val = db_val;
+		mhi_write_db(mhi_cntrl, db_addr, db_val);
+		db_cfg->db_mode = 0;
+	}
+}
+
+void mhi_db_brstmode_disable(struct mhi_controller *mhi_cntrl,
+			     struct db_cfg *db_cfg,
+			     void __iomem *db_addr,
+			     dma_addr_t db_val)
+{
+	db_cfg->db_val = db_val;
+	mhi_write_db(mhi_cntrl, db_addr, db_val);
+}
+
+void mhi_ring_er_db(struct mhi_event *mhi_event)
+{
+	struct mhi_ring *ring = &mhi_event->ring;
+
+	mhi_event->db_cfg.process_db(mhi_event->mhi_cntrl, &mhi_event->db_cfg,
+				     ring->db_addr, *ring->ctxt_wp);
+}
+
+void mhi_ring_cmd_db(struct mhi_controller *mhi_cntrl, struct mhi_cmd *mhi_cmd)
+{
+	dma_addr_t db;
+	struct mhi_ring *ring = &mhi_cmd->ring;
+
+	db = ring->iommu_base + (ring->wp - ring->base);
+	*ring->ctxt_wp = db;
+	mhi_write_db(mhi_cntrl, ring->db_addr, db);
+}
+
+void mhi_ring_chan_db(struct mhi_controller *mhi_cntrl,
+		      struct mhi_chan *mhi_chan)
+{
+	struct mhi_ring *ring = &mhi_chan->tre_ring;
+	dma_addr_t db;
+
+	db = ring->iommu_base + (ring->wp - ring->base);
+	*ring->ctxt_wp = db;
+	mhi_chan->db_cfg.process_db(mhi_cntrl, &mhi_chan->db_cfg,
+				    ring->db_addr, db);
+}
+
+enum mhi_ee_type mhi_get_exec_env(struct mhi_controller *mhi_cntrl)
+{
+	u32 exec;
+	int ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_EXECENV, &exec);
+
+	return (ret) ? MHI_EE_MAX : exec;
+}
+
+enum mhi_state mhi_get_mhi_state(struct mhi_controller *mhi_cntrl)
+{
+	u32 state;
+	int ret = mhi_read_reg_field(mhi_cntrl, mhi_cntrl->regs, MHISTATUS,
+				     MHISTATUS_MHISTATE_MASK,
+				     MHISTATUS_MHISTATE_SHIFT, &state);
+	return ret ? MHI_STATE_MAX : state;
+}
+
+int mhi_destroy_device(struct device *dev, void *data)
+{
+	struct mhi_device *mhi_dev;
+	struct mhi_controller *mhi_cntrl;
+
+	if (dev->bus != &mhi_bus_type)
+		return 0;
+
+	mhi_dev = to_mhi_device(dev);
+	mhi_cntrl = mhi_dev->mhi_cntrl;
+
+	/* Only destroy virtual devices thats attached to bus */
+	if (mhi_dev->dev_type ==  MHI_DEVICE_CONTROLLER)
+		return 0;
+
+	dev_dbg(mhi_cntrl->dev, "destroy device for chan:%s\n",
+		 mhi_dev->chan_name);
+
+	/* Notify the client and remove the device from MHI bus */
+	device_del(dev);
+	put_device(dev);
+
+	return 0;
+}
+
+void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason)
+{
+	struct mhi_driver *mhi_drv;
+
+	if (!mhi_dev->dev.driver)
+		return;
+
+	mhi_drv = to_mhi_driver(mhi_dev->dev.driver);
+
+	if (mhi_drv->status_cb)
+		mhi_drv->status_cb(mhi_dev, cb_reason);
+}
+
+/* Bind MHI channels to MHI devices */
+void mhi_create_devices(struct mhi_controller *mhi_cntrl)
+{
+	int i;
+	struct mhi_chan *mhi_chan;
+	struct mhi_device *mhi_dev;
+	int ret;
+
+	mhi_chan = mhi_cntrl->mhi_chan;
+	for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
+		if (!mhi_chan->configured || mhi_chan->mhi_dev ||
+		    !(mhi_chan->ee_mask & BIT(mhi_cntrl->ee)))
+			continue;
+		mhi_dev = mhi_alloc_device(mhi_cntrl);
+		if (!mhi_dev)
+			return;
+
+		mhi_dev->dev_type = MHI_DEVICE_XFER;
+		switch (mhi_chan->dir) {
+		case DMA_TO_DEVICE:
+			mhi_dev->ul_chan = mhi_chan;
+			mhi_dev->ul_chan_id = mhi_chan->chan;
+			break;
+		case DMA_FROM_DEVICE:
+			/* We use dl_chan as offload channels */
+			mhi_dev->dl_chan = mhi_chan;
+			mhi_dev->dl_chan_id = mhi_chan->chan;
+			break;
+		default:
+			dev_err(mhi_cntrl->dev, "Direction not supported\n");
+			mhi_dealloc_device(mhi_cntrl, mhi_dev);
+			return;
+		}
+
+		mhi_chan->mhi_dev = mhi_dev;
+
+		/* Check next channel if it matches */
+		if ((i + 1) < mhi_cntrl->max_chan && mhi_chan[1].configured) {
+			if (!strcmp(mhi_chan[1].name, mhi_chan->name)) {
+				i++;
+				mhi_chan++;
+				if (mhi_chan->dir == DMA_TO_DEVICE) {
+					mhi_dev->ul_chan = mhi_chan;
+					mhi_dev->ul_chan_id = mhi_chan->chan;
+				} else {
+					mhi_dev->dl_chan = mhi_chan;
+					mhi_dev->dl_chan_id = mhi_chan->chan;
+				}
+				mhi_chan->mhi_dev = mhi_dev;
+			}
+		}
+
+		mhi_dev->chan_name = mhi_chan->name;
+		dev_set_name(&mhi_dev->dev, "%04x_%s", mhi_chan->chan,
+			     mhi_dev->chan_name);
+
+		/* Init wakeup source if available */
+		if (mhi_dev->dl_chan && mhi_dev->dl_chan->wake_capable)
+			device_init_wakeup(&mhi_dev->dev, true);
+
+		ret = device_add(&mhi_dev->dev);
+		if (ret)
+			mhi_dealloc_device(mhi_cntrl, mhi_dev);
+	}
+}
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
new file mode 100644
index 000000000000..785dfd8d0b25
--- /dev/null
+++ b/drivers/bus/mhi/core/pm.c
@@ -0,0 +1,685 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
+ *
+ */
+
+#define dev_fmt(fmt) "MHI: " fmt
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/mhi.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+#include "internal.h"
+
+/*
+ * Not all MHI state transitions are synchronous. Transitions like Linkdown,
+ * SYS_ERR, and shutdown can happen anytime asynchronously. This function will
+ * transition to a new state only if we're allowed to.
+ *
+ * Priority increases as we go down. For instance, from any state in L0, the
+ * transition can be made to states in L1, L2 and L3. A notable exception to
+ * this rule is state DISABLE.  From DISABLE state we can only transition to
+ * POR state. Also, while in L2 state, user cannot jump back to previous
+ * L1 or L0 states.
+ *
+ * Valid transitions:
+ * L0: DISABLE <--> POR
+ *     POR <--> POR
+ *     POR -> M0 -> M2 --> M0
+ *     POR -> FW_DL_ERR
+ *     FW_DL_ERR <--> FW_DL_ERR
+ *     M0 <--> M0
+ *     M0 -> FW_DL_ERR
+ *     M0 -> M3_ENTER -> M3 -> M3_EXIT --> M0
+ * L1: SYS_ERR_DETECT -> SYS_ERR_PROCESS --> POR
+ * L2: SHUTDOWN_PROCESS -> DISABLE
+ * L3: LD_ERR_FATAL_DETECT <--> LD_ERR_FATAL_DETECT
+ *     LD_ERR_FATAL_DETECT -> SHUTDOWN_PROCESS
+ */
+static struct mhi_pm_transitions const dev_state_transitions[] = {
+	/* L0 States */
+	{
+		MHI_PM_DISABLE,
+		MHI_PM_POR
+	},
+	{
+		MHI_PM_POR,
+		MHI_PM_POR | MHI_PM_DISABLE | MHI_PM_M0 |
+		MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
+		MHI_PM_LD_ERR_FATAL_DETECT | MHI_PM_FW_DL_ERR
+	},
+	{
+		MHI_PM_M0,
+		MHI_PM_M0 | MHI_PM_M2 | MHI_PM_M3_ENTER |
+		MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
+		MHI_PM_LD_ERR_FATAL_DETECT | MHI_PM_FW_DL_ERR
+	},
+	{
+		MHI_PM_M2,
+		MHI_PM_M0 | MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
+		MHI_PM_LD_ERR_FATAL_DETECT
+	},
+	{
+		MHI_PM_M3_ENTER,
+		MHI_PM_M3 | MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
+		MHI_PM_LD_ERR_FATAL_DETECT
+	},
+	{
+		MHI_PM_M3,
+		MHI_PM_M3_EXIT | MHI_PM_SYS_ERR_DETECT |
+		MHI_PM_SHUTDOWN_PROCESS | MHI_PM_LD_ERR_FATAL_DETECT
+	},
+	{
+		MHI_PM_M3_EXIT,
+		MHI_PM_M0 | MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
+		MHI_PM_LD_ERR_FATAL_DETECT
+	},
+	{
+		MHI_PM_FW_DL_ERR,
+		MHI_PM_FW_DL_ERR | MHI_PM_SYS_ERR_DETECT |
+		MHI_PM_SHUTDOWN_PROCESS | MHI_PM_LD_ERR_FATAL_DETECT
+	},
+	/* L1 States */
+	{
+		MHI_PM_SYS_ERR_DETECT,
+		MHI_PM_SYS_ERR_PROCESS | MHI_PM_SHUTDOWN_PROCESS |
+		MHI_PM_LD_ERR_FATAL_DETECT
+	},
+	{
+		MHI_PM_SYS_ERR_PROCESS,
+		MHI_PM_POR | MHI_PM_SHUTDOWN_PROCESS |
+		MHI_PM_LD_ERR_FATAL_DETECT
+	},
+	/* L2 States */
+	{
+		MHI_PM_SHUTDOWN_PROCESS,
+		MHI_PM_DISABLE | MHI_PM_LD_ERR_FATAL_DETECT
+	},
+	/* L3 States */
+	{
+		MHI_PM_LD_ERR_FATAL_DETECT,
+		MHI_PM_LD_ERR_FATAL_DETECT | MHI_PM_SHUTDOWN_PROCESS
+	},
+};
+
+enum mhi_pm_state __must_check mhi_tryset_pm_state(struct mhi_controller *mhi_cntrl,
+						   enum mhi_pm_state state)
+{
+	unsigned long cur_state = mhi_cntrl->pm_state;
+	int index = find_last_bit(&cur_state, 32);
+
+	if (unlikely(index >= ARRAY_SIZE(dev_state_transitions)))
+		return cur_state;
+
+	if (unlikely(dev_state_transitions[index].from_state != cur_state))
+		return cur_state;
+
+	if (unlikely(!(dev_state_transitions[index].to_states & state)))
+		return cur_state;
+
+	mhi_cntrl->pm_state = state;
+	return mhi_cntrl->pm_state;
+}
+
+void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl, enum mhi_state state)
+{
+	if (state == MHI_STATE_RESET) {
+		mhi_write_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
+				    MHICTRL_RESET_MASK, MHICTRL_RESET_SHIFT, 1);
+	} else {
+		mhi_write_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
+				    MHICTRL_MHISTATE_MASK,
+				    MHICTRL_MHISTATE_SHIFT, state);
+	}
+}
+
+/* Handle device ready state transition */
+int mhi_ready_state_transition(struct mhi_controller *mhi_cntrl)
+{
+	void __iomem *base = mhi_cntrl->regs;
+	u32 reset = 1, ready = 0;
+	struct mhi_event *mhi_event;
+	enum mhi_pm_state cur_state;
+	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(mhi_cntrl->dev, "Device link is not accessible\n");
+		return -EIO;
+	}
+
+	/* Timeout if device did not transition to ready state */
+	if (reset || !ready) {
+		dev_err(mhi_cntrl->dev, "Device Ready timeout\n");
+		return -ETIMEDOUT;
+	}
+
+	dev_dbg(mhi_cntrl->dev, "Device in READY State\n");
+	write_lock_irq(&mhi_cntrl->pm_lock);
+	cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_POR);
+	mhi_cntrl->dev_state = MHI_STATE_READY;
+	write_unlock_irq(&mhi_cntrl->pm_lock);
+
+	if (cur_state != MHI_PM_POR) {
+		dev_err(mhi_cntrl->dev, "Error moving to state %s from %s\n",
+			to_mhi_pm_state_str(MHI_PM_POR),
+			to_mhi_pm_state_str(cur_state));
+		return -EIO;
+	}
+
+	read_lock_bh(&mhi_cntrl->pm_lock);
+	if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) {
+		dev_err(mhi_cntrl->dev, "Device registers not accessible\n");
+		goto error_mmio;
+	}
+
+	/* Configure MMIO registers */
+	ret = mhi_init_mmio(mhi_cntrl);
+	if (ret) {
+		dev_err(mhi_cntrl->dev, "Error configuring MMIO registers\n");
+		goto error_mmio;
+	}
+
+	/* Add elements to all SW event rings */
+	mhi_event = mhi_cntrl->mhi_event;
+	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
+		struct mhi_ring *ring = &mhi_event->ring;
+
+		/* Skip if this is an offload or HW event */
+		if (mhi_event->offload_ev || mhi_event->hw_ring)
+			continue;
+
+		ring->wp = ring->base + ring->len - ring->el_size;
+		*ring->ctxt_wp = ring->iommu_base + ring->len - ring->el_size;
+		/* Update all cores */
+		smp_wmb();
+
+		/* Ring the event ring db */
+		spin_lock_irq(&mhi_event->lock);
+		mhi_ring_er_db(mhi_event);
+		spin_unlock_irq(&mhi_event->lock);
+	}
+
+	/* Set MHI to M0 state */
+	mhi_set_mhi_state(mhi_cntrl, MHI_STATE_M0);
+	read_unlock_bh(&mhi_cntrl->pm_lock);
+
+	return 0;
+
+error_mmio:
+	read_unlock_bh(&mhi_cntrl->pm_lock);
+
+	return -EIO;
+}
+
+int mhi_pm_m0_transition(struct mhi_controller *mhi_cntrl)
+{
+	enum mhi_pm_state cur_state;
+	struct mhi_chan *mhi_chan;
+	int i;
+
+	write_lock_irq(&mhi_cntrl->pm_lock);
+	mhi_cntrl->dev_state = MHI_STATE_M0;
+	cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M0);
+	write_unlock_irq(&mhi_cntrl->pm_lock);
+	if (unlikely(cur_state != MHI_PM_M0)) {
+		dev_err(mhi_cntrl->dev, "Unable to transition to M0 state\n");
+		return -EIO;
+	}
+
+	mhi_cntrl->M0++;
+
+	/* Wake up the device */
+	read_lock_bh(&mhi_cntrl->pm_lock);
+	mhi_cntrl->wake_get(mhi_cntrl, true);
+
+	/* Ring all event rings and CMD ring only if we're in mission mode */
+	if (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) {
+		struct mhi_event *mhi_event = mhi_cntrl->mhi_event;
+		struct mhi_cmd *mhi_cmd =
+			&mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING];
+
+		for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
+			if (mhi_event->offload_ev)
+				continue;
+
+			spin_lock_irq(&mhi_event->lock);
+			mhi_ring_er_db(mhi_event);
+			spin_unlock_irq(&mhi_event->lock);
+		}
+
+		/* Only ring primary cmd ring if ring is not empty */
+		spin_lock_irq(&mhi_cmd->lock);
+		if (mhi_cmd->ring.rp != mhi_cmd->ring.wp)
+			mhi_ring_cmd_db(mhi_cntrl, mhi_cmd);
+		spin_unlock_irq(&mhi_cmd->lock);
+	}
+
+	/* Ring channel DB registers */
+	mhi_chan = mhi_cntrl->mhi_chan;
+	for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
+		struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
+
+		write_lock_irq(&mhi_chan->lock);
+		if (mhi_chan->db_cfg.reset_req)
+			mhi_chan->db_cfg.db_mode = true;
+
+		/* Only ring DB if ring is not empty */
+		if (tre_ring->base && tre_ring->wp  != tre_ring->rp)
+			mhi_ring_chan_db(mhi_cntrl, mhi_chan);
+		write_unlock_irq(&mhi_chan->lock);
+	}
+
+	mhi_cntrl->wake_put(mhi_cntrl, false);
+	read_unlock_bh(&mhi_cntrl->pm_lock);
+	wake_up_all(&mhi_cntrl->state_event);
+
+	return 0;
+}
+
+/*
+ * After receiving the MHI state change event from the device indicating the
+ * transition to M1 state, the host can transition the device to M2 state
+ * for keeping it in low power state.
+ */
+void mhi_pm_m1_transition(struct mhi_controller *mhi_cntrl)
+{
+	enum mhi_pm_state state;
+
+	write_lock_irq(&mhi_cntrl->pm_lock);
+	state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M2);
+	if (state == MHI_PM_M2) {
+		mhi_set_mhi_state(mhi_cntrl, MHI_STATE_M2);
+		mhi_cntrl->dev_state = MHI_STATE_M2;
+		mhi_cntrl->M2++;
+
+		write_unlock_irq(&mhi_cntrl->pm_lock);
+		wake_up_all(&mhi_cntrl->state_event);
+
+		/* If there are any pending resources, exit M2 immediately */
+		if (unlikely(atomic_read(&mhi_cntrl->pending_pkts) ||
+			     atomic_read(&mhi_cntrl->dev_wake))) {
+			dev_dbg(mhi_cntrl->dev,
+				 "Exiting M2, pending_pkts: %d dev_wake: %d\n",
+				 atomic_read(&mhi_cntrl->pending_pkts),
+				 atomic_read(&mhi_cntrl->dev_wake));
+			read_lock_bh(&mhi_cntrl->pm_lock);
+			mhi_cntrl->wake_get(mhi_cntrl, true);
+			mhi_cntrl->wake_put(mhi_cntrl, true);
+			read_unlock_bh(&mhi_cntrl->pm_lock);
+		} else {
+			mhi_cntrl->status_cb(mhi_cntrl, mhi_cntrl->priv_data,
+					     MHI_CB_IDLE);
+		}
+	} else {
+		write_unlock_irq(&mhi_cntrl->pm_lock);
+	}
+}
+
+/* MHI M3 completion handler */
+int mhi_pm_m3_transition(struct mhi_controller *mhi_cntrl)
+{
+	enum mhi_pm_state state;
+
+	write_lock_irq(&mhi_cntrl->pm_lock);
+	mhi_cntrl->dev_state = MHI_STATE_M3;
+	state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M3);
+	write_unlock_irq(&mhi_cntrl->pm_lock);
+	if (state != MHI_PM_M3) {
+		dev_err(mhi_cntrl->dev, "Unable to transition to M3 state\n");
+		return -EIO;
+	}
+
+	wake_up_all(&mhi_cntrl->state_event);
+	mhi_cntrl->M3++;
+
+	return 0;
+}
+
+/* Handle device Mission Mode transition */
+static int mhi_pm_mission_mode_transition(struct mhi_controller *mhi_cntrl)
+{
+	int i, ret;
+	struct mhi_event *mhi_event;
+
+	dev_dbg(mhi_cntrl->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);
+	write_unlock_irq(&mhi_cntrl->pm_lock);
+
+	if (!MHI_IN_MISSION_MODE(mhi_cntrl->ee))
+		return -EIO;
+
+	wake_up_all(&mhi_cntrl->state_event);
+
+	mhi_cntrl->status_cb(mhi_cntrl, mhi_cntrl->priv_data,
+			     MHI_CB_EE_MISSION_MODE);
+
+	/* Force MHI to be in M0 state before continuing */
+	ret = __mhi_device_get_sync(mhi_cntrl);
+	if (ret)
+		return ret;
+
+	read_lock_bh(&mhi_cntrl->pm_lock);
+
+	if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
+		ret = -EIO;
+		goto error_mission_mode;
+	}
+
+	/* Add elements to all HW event rings */
+	mhi_event = mhi_cntrl->mhi_event;
+	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
+		struct mhi_ring *ring = &mhi_event->ring;
+
+		if (mhi_event->offload_ev || !mhi_event->hw_ring)
+			continue;
+
+		ring->wp = ring->base + ring->len - ring->el_size;
+		*ring->ctxt_wp = ring->iommu_base + ring->len - ring->el_size;
+		/* Update to all cores */
+		smp_wmb();
+
+		spin_lock_irq(&mhi_event->lock);
+		if (MHI_DB_ACCESS_VALID(mhi_cntrl))
+			mhi_ring_er_db(mhi_event);
+		spin_unlock_irq(&mhi_event->lock);
+	}
+
+	read_unlock_bh(&mhi_cntrl->pm_lock);
+
+	/*
+	 * The MHI devices are only created when the client device switches its
+	 * Execution Environment (EE) to either SBL or AMSS states
+	 */
+	mhi_create_devices(mhi_cntrl);
+
+	read_lock_bh(&mhi_cntrl->pm_lock);
+
+error_mission_mode:
+	mhi_cntrl->wake_put(mhi_cntrl, false);
+	read_unlock_bh(&mhi_cntrl->pm_lock);
+
+	return ret;
+}
+
+/* Handle SYS_ERR and Shutdown transitions */
+static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
+				      enum mhi_pm_state transition_state)
+{
+	enum mhi_pm_state cur_state, prev_state;
+	struct mhi_event *mhi_event;
+	struct mhi_cmd_ctxt *cmd_ctxt;
+	struct mhi_cmd *mhi_cmd;
+	struct mhi_event_ctxt *er_ctxt;
+	int ret, i;
+
+	dev_dbg(mhi_cntrl->dev,
+		 "Transitioning from PM state: %s to: %s\n",
+		 to_mhi_pm_state_str(mhi_cntrl->pm_state),
+		 to_mhi_pm_state_str(transition_state));
+
+	/* We must notify MHI control driver so it can clean up first */
+	if (transition_state == MHI_PM_SYS_ERR_PROCESS) {
+		mhi_cntrl->status_cb(mhi_cntrl, mhi_cntrl->priv_data,
+				     MHI_CB_SYS_ERROR);
+	}
+
+	mutex_lock(&mhi_cntrl->pm_mutex);
+	write_lock_irq(&mhi_cntrl->pm_lock);
+	prev_state = mhi_cntrl->pm_state;
+	cur_state = mhi_tryset_pm_state(mhi_cntrl, transition_state);
+	if (cur_state == transition_state) {
+		mhi_cntrl->ee = MHI_EE_DISABLE_TRANSITION;
+		mhi_cntrl->dev_state = MHI_STATE_RESET;
+	}
+	write_unlock_irq(&mhi_cntrl->pm_lock);
+
+	/* Wake up threads waiting for state transition */
+	wake_up_all(&mhi_cntrl->state_event);
+
+	if (cur_state != transition_state) {
+		dev_err(mhi_cntrl->dev,
+			 "Failed to transition to state: %s from: %s\n",
+			 to_mhi_pm_state_str(transition_state),
+			 to_mhi_pm_state_str(cur_state));
+		mutex_unlock(&mhi_cntrl->pm_mutex);
+		return;
+	}
+
+	/* Trigger MHI RESET so that the device will not access host memory */
+	if (MHI_REG_ACCESS_VALID(prev_state)) {
+		u32 in_reset = -1;
+		unsigned long timeout = msecs_to_jiffies(mhi_cntrl->timeout_ms);
+
+		dev_dbg(mhi_cntrl->dev, "Triggering MHI Reset in device\n");
+		mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
+
+		/* Wait for the reset bit to be cleared by the device */
+		ret = wait_event_timeout(mhi_cntrl->state_event,
+					 mhi_read_reg_field(mhi_cntrl,
+							    mhi_cntrl->regs,
+							    MHICTRL,
+							    MHICTRL_RESET_MASK,
+							    MHICTRL_RESET_SHIFT,
+							    &in_reset) ||
+					!in_reset, timeout);
+		if ((!ret || in_reset) && cur_state == MHI_PM_SYS_ERR_PROCESS) {
+			dev_err(mhi_cntrl->dev,
+				"Device failed to exit MHI Reset state\n");
+			mutex_unlock(&mhi_cntrl->pm_mutex);
+			return;
+		}
+
+		/*
+		 * Device will clear BHI_INTVEC as a part of RESET processing,
+		 * hence re-program it
+		 */
+		mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
+	}
+
+	dev_dbg(mhi_cntrl->dev,
+		 "Waiting for all pending event ring processing to complete\n");
+	mhi_event = mhi_cntrl->mhi_event;
+	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
+		if (mhi_event->offload_ev)
+			continue;
+		tasklet_kill(&mhi_event->task);
+	}
+
+	/* Release lock and wait for all pending threads to complete */
+	mutex_unlock(&mhi_cntrl->pm_mutex);
+	dev_dbg(mhi_cntrl->dev,
+		 "Waiting for all pending threads to complete\n");
+	wake_up_all(&mhi_cntrl->state_event);
+	flush_work(&mhi_cntrl->st_worker);
+	flush_work(&mhi_cntrl->fw_worker);
+
+	dev_dbg(mhi_cntrl->dev,
+		 "Reset all active channels and remove MHI devices\n");
+	device_for_each_child(mhi_cntrl->dev, NULL, mhi_destroy_device);
+
+	mutex_lock(&mhi_cntrl->pm_mutex);
+
+	WARN_ON(atomic_read(&mhi_cntrl->dev_wake));
+	WARN_ON(atomic_read(&mhi_cntrl->pending_pkts));
+
+	/* Reset the ev rings and cmd rings */
+	dev_dbg(mhi_cntrl->dev, "Resetting EV CTXT and CMD CTXT\n");
+	mhi_cmd = mhi_cntrl->mhi_cmd;
+	cmd_ctxt = mhi_cntrl->mhi_ctxt->cmd_ctxt;
+	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) {
+		struct mhi_ring *ring = &mhi_cmd->ring;
+
+		ring->rp = ring->base;
+		ring->wp = ring->base;
+		cmd_ctxt->rp = cmd_ctxt->rbase;
+		cmd_ctxt->wp = cmd_ctxt->rbase;
+	}
+
+	mhi_event = mhi_cntrl->mhi_event;
+	er_ctxt = mhi_cntrl->mhi_ctxt->er_ctxt;
+	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++,
+		     mhi_event++) {
+		struct mhi_ring *ring = &mhi_event->ring;
+
+		/* Skip offload events */
+		if (mhi_event->offload_ev)
+			continue;
+
+		ring->rp = ring->base;
+		ring->wp = ring->base;
+		er_ctxt->rp = er_ctxt->rbase;
+		er_ctxt->wp = er_ctxt->rbase;
+	}
+
+	if (cur_state == MHI_PM_SYS_ERR_PROCESS) {
+		mhi_ready_state_transition(mhi_cntrl);
+	} else {
+		/* Move to disable state */
+		write_lock_irq(&mhi_cntrl->pm_lock);
+		cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_DISABLE);
+		write_unlock_irq(&mhi_cntrl->pm_lock);
+		if (unlikely(cur_state != MHI_PM_DISABLE))
+			dev_err(mhi_cntrl->dev,
+				"Error moving from PM state: %s to: %s\n",
+				to_mhi_pm_state_str(cur_state),
+				to_mhi_pm_state_str(MHI_PM_DISABLE));
+	}
+
+	dev_dbg(mhi_cntrl->dev, "Exiting 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));
+
+	mutex_unlock(&mhi_cntrl->pm_mutex);
+}
+
+/* Queue a new work item and schedule work */
+int mhi_queue_state_transition(struct mhi_controller *mhi_cntrl,
+			       enum dev_st_transition state)
+{
+	struct state_transition *item = kmalloc(sizeof(*item), GFP_ATOMIC);
+	unsigned long flags;
+
+	if (!item)
+		return -ENOMEM;
+
+	item->state = state;
+	spin_lock_irqsave(&mhi_cntrl->transition_lock, flags);
+	list_add_tail(&item->node, &mhi_cntrl->transition_list);
+	spin_unlock_irqrestore(&mhi_cntrl->transition_lock, flags);
+
+	schedule_work(&mhi_cntrl->st_worker);
+
+	return 0;
+}
+
+/* SYS_ERR worker */
+void mhi_pm_sys_err_worker(struct work_struct *work)
+{
+	struct mhi_controller *mhi_cntrl = container_of(work,
+							struct mhi_controller,
+							syserr_worker);
+
+	mhi_pm_disable_transition(mhi_cntrl, MHI_PM_SYS_ERR_PROCESS);
+}
+
+/* Device State Transition worker */
+void mhi_pm_st_worker(struct work_struct *work)
+{
+	struct state_transition *itr, *tmp;
+	LIST_HEAD(head);
+	struct mhi_controller *mhi_cntrl = container_of(work,
+							struct mhi_controller,
+							st_worker);
+	spin_lock_irq(&mhi_cntrl->transition_lock);
+	list_splice_tail_init(&mhi_cntrl->transition_list, &head);
+	spin_unlock_irq(&mhi_cntrl->transition_lock);
+
+	list_for_each_entry_safe(itr, tmp, &head, node) {
+		list_del(&itr->node);
+		dev_info(mhi_cntrl->dev, "Handling state transition: %s\n",
+			 TO_DEV_STATE_TRANS_STR(itr->state));
+
+		switch (itr->state) {
+		case DEV_ST_TRANSITION_PBL:
+			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);
+			write_unlock_irq(&mhi_cntrl->pm_lock);
+			if (MHI_IN_PBL(mhi_cntrl->ee))
+				wake_up_all(&mhi_cntrl->state_event);
+			break;
+		case DEV_ST_TRANSITION_SBL:
+			write_lock_irq(&mhi_cntrl->pm_lock);
+			mhi_cntrl->ee = MHI_EE_SBL;
+			write_unlock_irq(&mhi_cntrl->pm_lock);
+			/*
+			 * The MHI devices are only created when the client
+			 * device switches its Execution Environment (EE) to
+			 * either SBL or AMSS states
+			 */
+			mhi_create_devices(mhi_cntrl);
+			break;
+		case DEV_ST_TRANSITION_MISSION_MODE:
+			mhi_pm_mission_mode_transition(mhi_cntrl);
+			break;
+		case DEV_ST_TRANSITION_READY:
+			mhi_ready_state_transition(mhi_cntrl);
+			break;
+		default:
+			break;
+		}
+		kfree(itr);
+	}
+}
+
+int __mhi_device_get_sync(struct mhi_controller *mhi_cntrl)
+{
+	int ret;
+
+	/* Wake up the device */
+	read_lock_bh(&mhi_cntrl->pm_lock);
+	mhi_cntrl->wake_get(mhi_cntrl, true);
+	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) {
+		pm_wakeup_event(&mhi_cntrl->mhi_dev->dev, 0);
+		mhi_cntrl->runtime_get(mhi_cntrl, mhi_cntrl->priv_data);
+		mhi_cntrl->runtime_put(mhi_cntrl, mhi_cntrl->priv_data);
+	}
+	read_unlock_bh(&mhi_cntrl->pm_lock);
+
+	ret = wait_event_timeout(mhi_cntrl->state_event,
+				 mhi_cntrl->pm_state == MHI_PM_M0 ||
+				 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)) {
+		read_lock_bh(&mhi_cntrl->pm_lock);
+		mhi_cntrl->wake_put(mhi_cntrl, false);
+		read_unlock_bh(&mhi_cntrl->pm_lock);
+		return -EIO;
+	}
+
+	return 0;
+}
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 510fed65fd3a..fdae363d0142 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -84,6 +84,16 @@ enum mhi_ch_type {
 };
 
 /**
+ * struct mhi_link_info - BW requirement
+ * target_link_speed - Link speed as defined by TLS bits in LinkControl reg
+ * target_link_width - Link width as defined by NLW bits in LinkStatus reg
+ */
+struct mhi_link_info {
+	unsigned int target_link_speed;
+	unsigned int target_link_width;
+};
+
+/**
  * enum mhi_ee_type - Execution environment types
  * @MHI_EE_PBL: Primary Bootloader
  * @MHI_EE_SBL: Secondary Bootloader
@@ -108,6 +118,31 @@ enum mhi_ee_type {
 };
 
 /**
+ * enum mhi_state - MHI states
+ * @MHI_STATE_RESET: Reset state
+ * @MHI_STATE_READY: Ready state
+ * @MHI_STATE_M0: M0 state
+ * @MHI_STATE_M1: M1 state
+ * @MHI_STATE_M2: M2 state
+ * @MHI_STATE_M3: M3 state
+ * @MHI_STATE_M3_FAST: M3 Fast state
+ * @MHI_STATE_BHI: BHI state
+ * @MHI_STATE_SYS_ERR: System Error state
+ */
+enum mhi_state {
+	MHI_STATE_RESET = 0x0,
+	MHI_STATE_READY = 0x1,
+	MHI_STATE_M0 = 0x2,
+	MHI_STATE_M1 = 0x3,
+	MHI_STATE_M2 = 0x4,
+	MHI_STATE_M3 = 0x5,
+	MHI_STATE_M3_FAST = 0x6,
+	MHI_STATE_BHI = 0x7,
+	MHI_STATE_SYS_ERR = 0xFF,
+	MHI_STATE_MAX,
+};
+
+/**
  * enum mhi_buf_type - Accepted buffer type for the channel
  * @MHI_BUF_RAW: Raw buffer
  * @MHI_BUF_SKB: SKB struct
@@ -166,6 +201,7 @@ enum mhi_db_brst_mode {
  * @doorbell_mode_switch: Channel switches to doorbell mode on M0 transition
  * @auto_queue: Framework will automatically queue buffers for DL traffic
  * @auto_start: Automatically start (open) this channel
+ * @wake-capable: Channel capable of waking up the system
  */
 struct mhi_channel_config {
 	u32 num;
@@ -184,6 +220,7 @@ struct mhi_channel_config {
 	bool doorbell_mode_switch;
 	bool auto_queue;
 	bool auto_start;
+	bool wake_capable;
 };
 
 /**
@@ -244,6 +281,8 @@ struct mhi_controller_config {
  * @dev_id: Device ID of the controller
  * @bus_id: Physical bus instance used by the controller
  * @regs: Base address of MHI MMIO register space
+ * @bhi: Points to base of MHI BHI register space
+ * @wake_db: MHI WAKE doorbell register address
  * @iova_start: IOMMU starting address for data
  * @iova_stop: IOMMU stop address for data
  * @fw_image: Firmware image name for normal booting
@@ -271,12 +310,14 @@ struct mhi_controller_config {
  * @pm_state: MHI power management state
  * @db_access: DB access states
  * @ee: MHI device execution environment
+ * @dev_state: MHI device state
  * @wake_set: Device wakeup set flag
  * @dev_wake: Device wakeup count
  * @alloc_size: Total memory allocations size of the controller
  * @pending_pkts: Pending packets for the controller
  * @transition_list: List of MHI state transitions
  * @wlock: Lock for protecting device wakeup
+ * @mhi_link_info: Device bandwidth info
  * @M0: M0 state counter for debugging
  * @M2: M2 state counter for debugging
  * @M3: M3 state counter for debugging
@@ -307,6 +348,9 @@ struct mhi_controller {
 	u32 dev_id;
 	u32 bus_id;
 	void __iomem *regs;
+	void __iomem *bhi;
+	void __iomem *wake_db;
+
 	dma_addr_t iova_start;
 	dma_addr_t iova_stop;
 	const char *fw_image;
@@ -336,6 +380,7 @@ struct mhi_controller {
 	u32 pm_state;
 	u32 db_access;
 	enum mhi_ee_type ee;
+	enum mhi_state dev_state;
 	bool wake_set;
 	atomic_t dev_wake;
 	atomic_t alloc_size;
@@ -343,6 +388,8 @@ struct mhi_controller {
 	struct list_head transition_list;
 	spinlock_t transition_lock;
 	spinlock_t wlock;
+	struct mhi_link_info mhi_link_info;
+
 	u32 M0, M2, M3, M3_FAST;
 	struct work_struct st_worker;
 	struct work_struct fw_worker;
@@ -373,6 +420,8 @@ struct mhi_controller {
  * struct mhi_device - Structure representing a MHI device which binds
  *                     to channels
  * @dev: Driver model device node for the MHI device
+ * @ul_chan_id: MHI channel id for UL transfer
+ * @dl_chan_id: MHI channel id for DL transfer
  * @tiocm: Device current terminal settings
  * @id: Pointer to MHI device ID struct
  * @chan_name: Name of the channel to which the device binds
@@ -384,6 +433,8 @@ struct mhi_controller {
  */
 struct mhi_device {
 	struct device dev;
+	int ul_chan_id;
+	int dl_chan_id;
 	u32 tiocm;
 	const struct mhi_device_id *id;
 	const char *chan_name;
@@ -409,6 +460,22 @@ struct mhi_result {
 };
 
 /**
+ * struct mhi_buf - MHI Buffer description
+ * @buf: Virtual address of the buffer
+ * @dma_addr: IOMMU address of the buffer
+ * @len: # of bytes
+ * @name: Buffer label. For offload channel, configurations name must be:
+ *        ECA - Event context array data
+ *        CCA - Channel context array data
+ */
+struct mhi_buf {
+	void *buf;
+	dma_addr_t dma_addr;
+	size_t len;
+	const char *name;
+};
+
+/**
  * struct mhi_driver - Structure representing a MHI client driver
  * @probe: CB function for client driver probe function
  * @remove: CB function for client driver remove function
@@ -462,6 +529,25 @@ static inline void mhi_free_controller(struct mhi_controller *mhi_cntrl)
 }
 
 /**
+ * mhi_device_get - Disable device low power mode
+ * @mhi_dev: Device associated with the channel
+ */
+void mhi_device_get(struct mhi_device *mhi_dev);
+
+/**
+ * mhi_device_get_sync - Disable device low power mode. Synchronously
+ *                       take the controller out of suspended state
+ * @mhi_dev: Device associated with the channel
+ */
+int mhi_device_get_sync(struct mhi_device *mhi_dev);
+
+/**
+ * mhi_device_put - Re-enable device low power mode
+ * @mhi_dev: Device associated with the channel
+ */
+void mhi_device_put(struct mhi_device *mhi_dev);
+
+/**
  * mhi_alloc_controller - Allocate mhi_controller structure.
  */
 struct mhi_controller *mhi_alloc_controller(void);