Bluetooth: btintel_pcie: Add handshake between driver and firmware

The following handshake mechanism needs be followed after firmware
download is completed to bring the firmware to running state.

After firmware fragments of Operational image are downloaded and
secure sends result of the image succeeds,

1. Driver sends HCI Intel reset with boot option #1 to switch FW image.
2. FW sends Alive GP[0] MSIx
3. Driver enables data path (doorbell 0x460 for RBDs, etc...)
4. Driver gets Bootup event from firmware
5. Driver performs D0 entry to device (WRITE to IPC_Sleep_Control =0x0)
6. FW sends Alive GP[0] MSIx
7. Device host interface is fully set for BT protocol stack operation.
8. Driver may optionally get debug event with ID 0x97 which can be dropped

For Intermediate loadger image, all the above steps are applicable
expcept #5 and #6.

On HCI_OP_RESET, firmware raises alive interrupt. Driver needs to wait
for it before passing control over to bluetooth stack.

Co-developed-by: Devegowda Chandrashekar <chandrashekar.devegowda@intel.com>
Signed-off-by: Devegowda Chandrashekar <chandrashekar.devegowda@intel.com>
Signed-off-by: Kiran K <kiran.k@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

1 files changed, 255 insertions, 7 deletions

diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c
index 5252125b003f..16ee962d4086 100644
--- a/drivers/bluetooth/btintel_pcie.c
+++ b/drivers/bluetooth/btintel_pcie.c
@@ -48,6 +48,17 @@ MODULE_DEVICE_TABLE(pci, btintel_pcie_table);
 #define BTINTEL_PCIE_HCI_EVT_PKT	0x00000004
 #define BTINTEL_PCIE_HCI_ISO_PKT	0x00000005
 
+/* Alive interrupt context */
+enum {
+	BTINTEL_PCIE_ROM,
+	BTINTEL_PCIE_FW_DL,
+	BTINTEL_PCIE_HCI_RESET,
+	BTINTEL_PCIE_INTEL_HCI_RESET1,
+	BTINTEL_PCIE_INTEL_HCI_RESET2,
+	BTINTEL_PCIE_D0,
+	BTINTEL_PCIE_D3
+};
+
 static inline void ipc_print_ia_ring(struct hci_dev *hdev, struct ia *ia,
 				     u16 queue_num)
 {
@@ -290,8 +301,9 @@ static int btintel_pcie_enable_bt(struct btintel_pcie_data *data)
 	/* wait for interrupt from the device after booting up to primary
 	 * bootloader.
 	 */
+	data->alive_intr_ctxt = BTINTEL_PCIE_ROM;
 	err = wait_event_timeout(data->gp0_wait_q, data->gp0_received,
-				 msecs_to_jiffies(BTINTEL_DEFAULT_INTR_TIMEOUT));
+				 msecs_to_jiffies(BTINTEL_DEFAULT_INTR_TIMEOUT_MS));
 	if (!err)
 		return -ETIME;
 
@@ -302,12 +314,78 @@ static int btintel_pcie_enable_bt(struct btintel_pcie_data *data)
 	return 0;
 }
 
+/* BIT(0) - ROM, BIT(1) - IML and BIT(3) - OP
+ * Sometimes during firmware image switching from ROM to IML or IML to OP image,
+ * the previous image bit is not cleared by firmware when alive interrupt is
+ * received. Driver needs to take care of these sticky bits when deciding the
+ * current image running on controller.
+ * Ex: 0x10 and 0x11 - both represents that controller is running IML
+ */
+static inline bool btintel_pcie_in_rom(struct btintel_pcie_data *data)
+{
+	return data->boot_stage_cache & BTINTEL_PCIE_CSR_BOOT_STAGE_ROM &&
+		!(data->boot_stage_cache & BTINTEL_PCIE_CSR_BOOT_STAGE_IML) &&
+		!(data->boot_stage_cache & BTINTEL_PCIE_CSR_BOOT_STAGE_OPFW);
+}
+
+static inline bool btintel_pcie_in_op(struct btintel_pcie_data *data)
+{
+	return data->boot_stage_cache & BTINTEL_PCIE_CSR_BOOT_STAGE_OPFW;
+}
+
+static inline bool btintel_pcie_in_iml(struct btintel_pcie_data *data)
+{
+	return data->boot_stage_cache & BTINTEL_PCIE_CSR_BOOT_STAGE_IML &&
+		!(data->boot_stage_cache & BTINTEL_PCIE_CSR_BOOT_STAGE_OPFW);
+}
+
+static inline bool btintel_pcie_in_d3(struct btintel_pcie_data *data)
+{
+	return data->boot_stage_cache & BTINTEL_PCIE_CSR_BOOT_STAGE_D3_STATE_READY;
+}
+
+static inline bool btintel_pcie_in_d0(struct btintel_pcie_data *data)
+{
+	return !(data->boot_stage_cache & BTINTEL_PCIE_CSR_BOOT_STAGE_D3_STATE_READY);
+}
+
+static void btintel_pcie_wr_sleep_cntrl(struct btintel_pcie_data *data,
+					u32 dxstate)
+{
+	bt_dev_dbg(data->hdev, "writing sleep_ctl_reg: 0x%8.8x", dxstate);
+	btintel_pcie_wr_reg32(data, BTINTEL_PCIE_CSR_IPC_SLEEP_CTL_REG, dxstate);
+}
+
+static inline char *btintel_pcie_alivectxt_state2str(u32 alive_intr_ctxt)
+{
+	switch (alive_intr_ctxt) {
+	case BTINTEL_PCIE_ROM:
+		return "rom";
+	case BTINTEL_PCIE_FW_DL:
+		return "fw_dl";
+	case BTINTEL_PCIE_D0:
+		return "d0";
+	case BTINTEL_PCIE_D3:
+		return "d3";
+	case BTINTEL_PCIE_HCI_RESET:
+		return "hci_reset";
+	case BTINTEL_PCIE_INTEL_HCI_RESET1:
+		return "intel_reset1";
+	case BTINTEL_PCIE_INTEL_HCI_RESET2:
+		return "intel_reset2";
+	default:
+		return "unknown";
+	}
+	return "null";
+}
+
 /* This function handles the MSI-X interrupt for gp0 cause (bit 0 in
  * BTINTEL_PCIE_CSR_MSIX_HW_INT_CAUSES) which is sent for boot stage and image response.
  */
 static void btintel_pcie_msix_gp0_handler(struct btintel_pcie_data *data)
 {
-	u32 reg;
+	bool submit_rx, signal_waitq;
+	u32 reg, old_ctxt;
 
 	/* This interrupt is for three different causes and it is not easy to
 	 * know what causes the interrupt. So, it compares each register value
@@ -317,20 +395,87 @@ static void btintel_pcie_msix_gp0_handler(struct btintel_pcie_data *data)
 	if (reg != data->boot_stage_cache)
 		data->boot_stage_cache = reg;
 
+	bt_dev_dbg(data->hdev, "Alive context: %s old_boot_stage: 0x%8.8x new_boot_stage: 0x%8.8x",
+		   btintel_pcie_alivectxt_state2str(data->alive_intr_ctxt),
+		   data->boot_stage_cache, reg);
 	reg = btintel_pcie_rd_reg32(data, BTINTEL_PCIE_CSR_IMG_RESPONSE_REG);
 	if (reg != data->img_resp_cache)
 		data->img_resp_cache = reg;
 
 	data->gp0_received = true;
 
-	/* If the boot stage is OP or IML, reset IA and start RX again */
-	if (data->boot_stage_cache & BTINTEL_PCIE_CSR_BOOT_STAGE_OPFW ||
-	    data->boot_stage_cache & BTINTEL_PCIE_CSR_BOOT_STAGE_IML) {
+	old_ctxt = data->alive_intr_ctxt;
+	submit_rx = false;
+	signal_waitq = false;
+
+	switch (data->alive_intr_ctxt) {
+	case BTINTEL_PCIE_ROM:
+		data->alive_intr_ctxt = BTINTEL_PCIE_FW_DL;
+		signal_waitq = true;
+		break;
+	case BTINTEL_PCIE_FW_DL:
+		/* Error case is already handled. Ideally control shall not
+		 * reach here
+		 */
+		break;
+	case BTINTEL_PCIE_INTEL_HCI_RESET1:
+		if (btintel_pcie_in_op(data)) {
+			submit_rx = true;
+			break;
+		}
+
+		if (btintel_pcie_in_iml(data)) {
+			submit_rx = true;
+			data->alive_intr_ctxt = BTINTEL_PCIE_FW_DL;
+			break;
+		}
+		break;
+	case BTINTEL_PCIE_INTEL_HCI_RESET2:
+		if (btintel_test_and_clear_flag(data->hdev, INTEL_WAIT_FOR_D0)) {
+			btintel_wake_up_flag(data->hdev, INTEL_WAIT_FOR_D0);
+			data->alive_intr_ctxt = BTINTEL_PCIE_D0;
+		}
+		break;
+	case BTINTEL_PCIE_D0:
+		if (btintel_pcie_in_d3(data)) {
+			data->alive_intr_ctxt = BTINTEL_PCIE_D3;
+			signal_waitq = true;
+			break;
+		}
+		break;
+	case BTINTEL_PCIE_D3:
+		if (btintel_pcie_in_d0(data)) {
+			data->alive_intr_ctxt = BTINTEL_PCIE_D0;
+			submit_rx = true;
+			signal_waitq = true;
+			break;
+		}
+		break;
+	case BTINTEL_PCIE_HCI_RESET:
+		data->alive_intr_ctxt = BTINTEL_PCIE_D0;
+		submit_rx = true;
+		signal_waitq = true;
+		break;
+	default:
+		bt_dev_err(data->hdev, "Unknown state: 0x%2.2x",
+			   data->alive_intr_ctxt);
+		break;
+	}
+
+	if (submit_rx) {
 		btintel_pcie_reset_ia(data);
 		btintel_pcie_start_rx(data);
 	}
 
-	wake_up(&data->gp0_wait_q);
+	if (signal_waitq) {
+		bt_dev_dbg(data->hdev, "wake up gp0 wait_q");
+		wake_up(&data->gp0_wait_q);
+	}
+
+	if (old_ctxt != data->alive_intr_ctxt)
+		bt_dev_dbg(data->hdev, "alive context changed: %s  ->  %s",
+			   btintel_pcie_alivectxt_state2str(old_ctxt),
+			   btintel_pcie_alivectxt_state2str(data->alive_intr_ctxt));
 }
 
 /* This function handles the MSX-X interrupt for rx queue 0 which is for TX
@@ -364,6 +509,80 @@ static void btintel_pcie_msix_tx_handle(struct btintel_pcie_data *data)
 	}
 }
 
+static int btintel_pcie_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct hci_event_hdr *hdr = (void *)skb->data;
+	const char diagnostics_hdr[] = { 0x87, 0x80, 0x03 };
+	struct btintel_pcie_data *data = hci_get_drvdata(hdev);
+
+	if (skb->len > HCI_EVENT_HDR_SIZE && hdr->evt == 0xff &&
+	    hdr->plen > 0) {
+		const void *ptr = skb->data + HCI_EVENT_HDR_SIZE + 1;
+		unsigned int len = skb->len - HCI_EVENT_HDR_SIZE - 1;
+
+		if (btintel_test_flag(hdev, INTEL_BOOTLOADER)) {
+			switch (skb->data[2]) {
+			case 0x02:
+				/* When switching to the operational firmware
+				 * the device sends a vendor specific event
+				 * indicating that the bootup completed.
+				 */
+				btintel_bootup(hdev, ptr, len);
+
+				/* If bootup event is from operational image,
+				 * driver needs to write sleep control register to
+				 * move into D0 state
+				 */
+				if (btintel_pcie_in_op(data)) {
+					btintel_pcie_wr_sleep_cntrl(data, BTINTEL_PCIE_STATE_D0);
+					data->alive_intr_ctxt = BTINTEL_PCIE_INTEL_HCI_RESET2;
+					break;
+				}
+
+				if (btintel_pcie_in_iml(data)) {
+					/* In case of IML, there is no concept
+					 * of D0 transition. Just mimic as if
+					 * IML moved to D0 by clearing INTEL_WAIT_FOR_D0
+					 * bit and waking up the task waiting on
+					 * INTEL_WAIT_FOR_D0. This is required
+					 * as intel_boot() is common function for
+					 * both IML and OP image loading.
+					 */
+					if (btintel_test_and_clear_flag(data->hdev,
+									INTEL_WAIT_FOR_D0))
+						btintel_wake_up_flag(data->hdev,
+								     INTEL_WAIT_FOR_D0);
+				}
+				break;
+			case 0x06:
+				/* When the firmware loading completes the
+				 * device sends out a vendor specific event
+				 * indicating the result of the firmware
+				 * loading.
+				 */
+				btintel_secure_send_result(hdev, ptr, len);
+				break;
+			}
+		}
+
+		/* Handle all diagnostics events separately. May still call
+		 * hci_recv_frame.
+		 */
+		if (len >= sizeof(diagnostics_hdr) &&
+		    memcmp(&skb->data[2], diagnostics_hdr,
+			   sizeof(diagnostics_hdr)) == 0) {
+			return btintel_diagnostics(hdev, skb);
+		}
+
+		/* This is a debug event that comes from IML and OP image when it
+		 * starts execution. There is no need pass this event to stack.
+		 */
+		if (skb->data[2] == 0x97)
+			return 0;
+	}
+
+	return hci_recv_frame(hdev, skb);
+}
 /* Process the received rx data
  * It check the frame header to identify the data type and create skb
  * and calling HCI API
@@ -465,7 +684,7 @@ static int btintel_pcie_recv_frame(struct btintel_pcie_data *data,
 	hdev->stat.byte_rx += plen;
 
 	if (pcie_pkt_type == BTINTEL_PCIE_HCI_EVT_PKT)
-		ret = btintel_recv_event(hdev, new_skb);
+		ret = btintel_pcie_recv_event(hdev, new_skb);
 	else
 		ret = hci_recv_frame(hdev, new_skb);
 
@@ -1053,8 +1272,11 @@ static int btintel_pcie_send_frame(struct hci_dev *hdev,
 				       struct sk_buff *skb)
 {
 	struct btintel_pcie_data *data = hci_get_drvdata(hdev);
+	struct hci_command_hdr *cmd;
+	__u16 opcode = ~0;
 	int ret;
 	u32 type;
+	u32 old_ctxt;
 
 	/* Due to the fw limitation, the type header of the packet should be
 	 * 4 bytes unlike 1 byte for UART. In UART, the firmware can read
@@ -1073,6 +1295,8 @@ static int btintel_pcie_send_frame(struct hci_dev *hdev,
 	switch (hci_skb_pkt_type(skb)) {
 	case HCI_COMMAND_PKT:
 		type = BTINTEL_PCIE_HCI_CMD_PKT;
+		cmd = (void *)skb->data;
+		opcode = le16_to_cpu(cmd->opcode);
 		if (btintel_test_flag(hdev, INTEL_BOOTLOADER)) {
 			struct hci_command_hdr *cmd = (void *)skb->data;
 			__u16 opcode = le16_to_cpu(cmd->opcode);
@@ -1111,6 +1335,30 @@ static int btintel_pcie_send_frame(struct hci_dev *hdev,
 		bt_dev_err(hdev, "Failed to send frame (%d)", ret);
 		goto exit_error;
 	}
+
+	if (type == BTINTEL_PCIE_HCI_CMD_PKT &&
+	    (opcode == HCI_OP_RESET || opcode == 0xfc01)) {
+		old_ctxt = data->alive_intr_ctxt;
+		data->alive_intr_ctxt =
+			(opcode == 0xfc01 ? BTINTEL_PCIE_INTEL_HCI_RESET1 :
+				BTINTEL_PCIE_HCI_RESET);
+		bt_dev_dbg(data->hdev, "sent cmd: 0x%4.4x alive context changed: %s  ->  %s",
+			   opcode, btintel_pcie_alivectxt_state2str(old_ctxt),
+			   btintel_pcie_alivectxt_state2str(data->alive_intr_ctxt));
+		if (opcode == HCI_OP_RESET) {
+			data->gp0_received = false;
+			ret = wait_event_timeout(data->gp0_wait_q,
+						 data->gp0_received,
+						 msecs_to_jiffies(BTINTEL_DEFAULT_INTR_TIMEOUT_MS));
+			if (!ret) {
+				hdev->stat.err_tx++;
+				bt_dev_err(hdev, "No alive interrupt received for %s",
+					   btintel_pcie_alivectxt_state2str(data->alive_intr_ctxt));
+				ret = -ETIME;
+				goto exit_error;
+			}
+		}
+	}
 	hdev->stat.byte_tx += skb->len;
 	kfree_skb(skb);