mhi: core: Preserve DB Mode state during lpm

When exiting low power modes (M3) do not reset
the DB Mode state if DB mode preserve flag is
set for channel.

CRs-Fixed: 1022868
Change-Id: I6557d28afe9d0ac11b76c683ffba76d7d6ffd377
Signed-off-by: Sujeev Dias <sdias@codeaurora.org>

5 files changed, 51 insertions, 29 deletions

diff --git a/drivers/platform/msm/mhi/mhi.h b/drivers/platform/msm/mhi/mhi.h
index c6fa39d6e0e2..3ecc7ce5df1e 100644
--- a/drivers/platform/msm/mhi/mhi.h
+++ b/drivers/platform/msm/mhi/mhi.h
@@ -261,6 +261,12 @@ enum MHI_EVENT_CCS {
 	MHI_EVENT_CC_BAD_TRE = 0x11,
 };
 
+struct db_mode {
+	/* if set do not reset DB_Mode during M0 resume */
+	u32 preserve_db_state : 1;
+	u32 db_mode : 1;
+};
+
 struct mhi_ring {
 	void *base;
 	void *wp;
@@ -270,6 +276,7 @@ struct mhi_ring {
 	uintptr_t el_size;
 	u32 overwrite_en;
 	enum MHI_CHAN_DIR dir;
+	struct db_mode db_mode;
 };
 
 enum MHI_CMD_STATUS {
@@ -414,7 +421,6 @@ struct mhi_flags {
 	u32 ev_thread_stopped;
 	u32 st_thread_stopped;
 	u32 uldl_enabled;
-	u32 db_mode[MHI_MAX_CHANNELS];
 };
 
 struct mhi_wait_queues {
@@ -577,7 +583,8 @@ int mhi_init_chan_ctxt(struct mhi_chan_ctxt *cc_list,
 				   enum MHI_CHAN_DIR chan_type,
 				   u32 event_ring,
 				   struct mhi_ring *ring,
-				   enum MHI_CHAN_STATE chan_state);
+				   enum MHI_CHAN_STATE chan_state,
+				   bool preserve_db_state);
 int mhi_populate_event_cfg(struct mhi_device_ctxt *mhi_dev_ctxt);
 int mhi_get_event_ring_for_channel(struct mhi_device_ctxt *mhi_dev_ctxt,
 					      u32 chan);
diff --git a/drivers/platform/msm/mhi/mhi_init.c b/drivers/platform/msm/mhi/mhi_init.c
index 93c3de35473b..2982bd0831c7 100644
--- a/drivers/platform/msm/mhi/mhi_init.c
+++ b/drivers/platform/msm/mhi/mhi_init.c
@@ -585,21 +585,23 @@ error_during_props:
 /**
  * @brief Initialize the channel context and shadow context
  *
- * @cc_list:		Context to initialize
- * @trb_list_phy:	Physical base address for the TRE ring
- * @trb_list_virt:	Virtual base address for the TRE ring
- * @el_per_ring:	Number of TREs this ring will contain
- * @chan_type:		Type of channel IN/OUT
- * @event_ring:	 Event ring to be mapped to this channel context
- * @ring:		 Shadow context to be initialized alongside
- *
+ * @cc_list: Context to initialize
+ * @trb_list_phy: Physical base address for the TRE ring
+ * @trb_list_virt: Virtual base address for the TRE ring
+ * @el_per_ring: Number of TREs this ring will contain
+ * @chan_type: Type of channel IN/OUT
+ * @event_ring: Event ring to be mapped to this channel context
+ * @ring: Shadow context to be initialized alongside
+ * @chan_state: Channel state
+ * @preserve_db_state: Do not reset DB state during resume
  * @Return errno
  */
 int mhi_init_chan_ctxt(struct mhi_chan_ctxt *cc_list,
-		uintptr_t trb_list_phy, uintptr_t trb_list_virt,
-		u64 el_per_ring, enum MHI_CHAN_DIR chan_type,
-		u32 event_ring, struct mhi_ring *ring,
-		enum MHI_CHAN_STATE chan_state)
+		       uintptr_t trb_list_phy, uintptr_t trb_list_virt,
+		       u64 el_per_ring, enum MHI_CHAN_DIR chan_type,
+		       u32 event_ring, struct mhi_ring *ring,
+		       enum MHI_CHAN_STATE chan_state,
+		       bool preserve_db_state)
 {
 	cc_list->mhi_chan_state = chan_state;
 	cc_list->mhi_chan_type = chan_type;
@@ -617,6 +619,8 @@ int mhi_init_chan_ctxt(struct mhi_chan_ctxt *cc_list,
 	ring->el_size = sizeof(struct mhi_tx_pkt);
 	ring->overwrite_en = 0;
 	ring->dir = chan_type;
+	ring->db_mode.db_mode = 1;
+	ring->db_mode.preserve_db_state = (preserve_db_state) ? 1 : 0;
 	/* Flush writes to MMIO */
 	wmb();
 	return 0;
diff --git a/drivers/platform/msm/mhi/mhi_macros.h b/drivers/platform/msm/mhi/mhi_macros.h
index bb47f53e244d..6701f3761aaa 100644
--- a/drivers/platform/msm/mhi/mhi_macros.h
+++ b/drivers/platform/msm/mhi/mhi_macros.h
@@ -244,6 +244,10 @@
 #define MHI_CHAN_TYPE__MASK (3)
 #define MHI_CHAN_TYPE__SHIFT (6)
 
+#define PRESERVE_DB_STATE
+#define MHI_PRESERVE_DB_STATE__MASK (1)
+#define MHI_PRESERVE_DB_STATE__SHIFT (8)
+
 #define GET_CHAN_PROPS(_FIELD, _VAL) \
 	(((_VAL) >> MHI_##_FIELD ## __SHIFT) & MHI_##_FIELD ## __MASK)
 
diff --git a/drivers/platform/msm/mhi/mhi_main.c b/drivers/platform/msm/mhi/mhi_main.c
index a1d6dfd4be4d..bc5f305e580b 100644
--- a/drivers/platform/msm/mhi/mhi_main.c
+++ b/drivers/platform/msm/mhi/mhi_main.c
@@ -212,7 +212,7 @@ int mhi_release_chan_ctxt(struct mhi_device_ctxt *mhi_dev_ctxt,
 			ring->len, ring->base,
 			 cc_list->mhi_trb_ring_base_addr);
 	mhi_init_chan_ctxt(cc_list, 0, 0, 0, 0, 0, ring,
-				MHI_CHAN_STATE_DISABLED);
+			   MHI_CHAN_STATE_DISABLED, false);
 	return 0;
 }
 
@@ -259,7 +259,9 @@ static int populate_tre_ring(struct mhi_client_handle *client_handle)
 				client_handle->chan_info.flags),
 			   client_handle->chan_info.ev_ring,
 			   &mhi_dev_ctxt->mhi_local_chan_ctxt[chan],
-			   MHI_CHAN_STATE_ENABLED);
+			   MHI_CHAN_STATE_ENABLED,
+			   GET_CHAN_PROPS(PRESERVE_DB_STATE,
+				client_handle->chan_info.flags));
 	mhi_log(MHI_MSG_INFO, "Exited\n");
 	return 0;
 }
@@ -654,6 +656,7 @@ static int mhi_queue_dma_xfer(
 	MHI_ASSERT(VALID_BUF(buf, buf_len, mhi_dev_ctxt),
 			"Client buffer is of invalid length\n");
 	chan = client_handle->chan_info.chan_nr;
+
 	mhi_log(MHI_MSG_INFO, "Getting Reference %d", chan);
 	pm_runtime_get(&mhi_dev_ctxt->dev_info->pcie_device->dev);
 
@@ -698,6 +701,7 @@ static int mhi_queue_dma_xfer(
 
 error:
 	pm_runtime_mark_last_busy(&mhi_dev_ctxt->dev_info->pcie_device->dev);
+
 	mhi_log(MHI_MSG_INFO, "Putting Reference %d", chan);
 	pm_runtime_put_noidle(&mhi_dev_ctxt->dev_info->pcie_device->dev);
 	return ret_val;
@@ -1169,12 +1173,13 @@ int parse_xfer_event(struct mhi_device_ctxt *ctxt,
 
 		mhi_dev_ctxt->flags.uldl_enabled = 1;
 		chan = MHI_EV_READ_CHID(EV_CHID, event);
-		mhi_dev_ctxt->flags.db_mode[chan] = 1;
 		chan_ctxt =
 			&mhi_dev_ctxt->mhi_local_chan_ctxt[chan];
+
 		mhi_log(MHI_MSG_INFO, "DB_MODE/OOB Detected chan %d.\n", chan);
 		spin_lock_irqsave(&mhi_dev_ctxt->db_write_lock[chan],
 				  flags);
+		chan_ctxt->db_mode.db_mode = 1;
 		if (chan_ctxt->wp != chan_ctxt->rp) {
 			db_value = mhi_v2p_addr(mhi_dev_ctxt,
 						MHI_RING_TYPE_XFER_RING, chan,
@@ -1658,6 +1663,8 @@ void mhi_process_db(struct mhi_device_ctxt *mhi_dev_ctxt,
 		  void __iomem *io_addr,
 		  uintptr_t chan, u32 val)
 {
+	struct mhi_ring *chan_ctxt = &mhi_dev_ctxt->mhi_local_chan_ctxt[chan];
+
 	mhi_log(MHI_MSG_VERBOSE,
 			"db.set addr: %p io_offset 0x%lx val:0x%x\n",
 			io_addr, chan, val);
@@ -1668,14 +1675,14 @@ void mhi_process_db(struct mhi_device_ctxt *mhi_dev_ctxt,
 	if (io_addr == mhi_dev_ctxt->mmio_info.chan_db_addr) {
 		if (!(IS_HARDWARE_CHANNEL(chan) &&
 		    mhi_dev_ctxt->flags.uldl_enabled &&
-		    !mhi_dev_ctxt->flags.db_mode[chan])) {
+		    !chan_ctxt->db_mode.db_mode)) {
 			mhi_write_db(mhi_dev_ctxt, io_addr, chan, val);
-			mhi_dev_ctxt->flags.db_mode[chan] = 0;
+			chan_ctxt->db_mode.db_mode = 0;
 		} else {
 			mhi_log(MHI_MSG_INFO,
-			 "Not ringing xfer db, chan %ld, ul_dl %d db_mode %d\n",
-			  chan, mhi_dev_ctxt->flags.uldl_enabled,
-				mhi_dev_ctxt->flags.db_mode[chan]);
+				"Not ringing xfer db, chan %ld, ul_dl %d db_mode %d\n",
+				chan, mhi_dev_ctxt->flags.uldl_enabled,
+				chan_ctxt->db_mode.db_mode);
 		}
 	/* Event Doorbell and Polling mode Disabled */
 	} else if (io_addr == mhi_dev_ctxt->mmio_info.event_db_addr) {
@@ -1683,11 +1690,9 @@ void mhi_process_db(struct mhi_device_ctxt *mhi_dev_ctxt,
 		if (IS_SW_EV_RING(mhi_dev_ctxt, chan) ||
 		    !mhi_dev_ctxt->flags.uldl_enabled) {
 			mhi_write_db(mhi_dev_ctxt, io_addr, chan, val);
-			mhi_dev_ctxt->flags.db_mode[chan] = 0;
 		}
 	} else {
 		mhi_write_db(mhi_dev_ctxt, io_addr, chan, val);
-		mhi_dev_ctxt->flags.db_mode[chan] = 0;
 	}
 }
 
diff --git a/drivers/platform/msm/mhi/mhi_states.c b/drivers/platform/msm/mhi/mhi_states.c
index 5dca3b65e38d..f0404da98cf7 100644
--- a/drivers/platform/msm/mhi/mhi_states.c
+++ b/drivers/platform/msm/mhi/mhi_states.c
@@ -90,11 +90,13 @@ static void ring_all_chan_dbs(struct mhi_device_ctxt *mhi_dev_ctxt,
 	for (i = 0; i < MHI_MAX_CHANNELS; ++i)
 		if (VALID_CHAN_NR(i)) {
 			local_ctxt = &mhi_dev_ctxt->mhi_local_chan_ctxt[i];
-			if (IS_HARDWARE_CHANNEL(i) && reset_db_mode)
-				mhi_dev_ctxt->flags.db_mode[i] = 1;
-			if ((local_ctxt->wp != local_ctxt->rp) ||
-			   ((local_ctxt->wp != local_ctxt->rp) &&
-			    (local_ctxt->dir == MHI_IN)))
+
+			/* Reset the DB Mode state to DB Mode */
+			if (local_ctxt->db_mode.preserve_db_state == 0
+			    && reset_db_mode)
+				local_ctxt->db_mode.db_mode = 1;
+
+			if (local_ctxt->wp != local_ctxt->rp)
 				conditional_chan_db_write(mhi_dev_ctxt, i);
 		}
 }