[net-next v3 1/3] wwan: core: Add WWAN fastboot port type

[net-next v3 1/3] wwan: core: Add WWAN fastboot port type

[Jinjian Song]

From: Jinjian Song <jinjian.song@fibocom.com>

Add a new WWAN port that connects to the device fastboot protocol
interface.

Signed-off-by: Jinjian Song <jinjian.song@fibocom.com>
---
v3:
 * no change
v2:
 * no change 
---
 drivers/net/wwan/wwan_core.c | 4 ++++
 include/linux/wwan.h         | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c
index 72e01e550a16..2ed20b20e7fc 100644
--- a/drivers/net/wwan/wwan_core.c
+++ b/drivers/net/wwan/wwan_core.c
@@ -328,6 +328,10 @@ static const struct {
 		.name = "XMMRPC",
 		.devsuf = "xmmrpc",
 	},
+	[WWAN_PORT_FASTBOOT] = {
+		.name = "FASTBOOT",
+		.devsuf = "fastboot",
+	},
 };
 
 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
diff --git a/include/linux/wwan.h b/include/linux/wwan.h
index 01fa15506286..170fdee6339c 100644
--- a/include/linux/wwan.h
+++ b/include/linux/wwan.h
@@ -16,6 +16,7 @@
  * @WWAN_PORT_QCDM: Qcom Modem diagnostic interface
  * @WWAN_PORT_FIREHOSE: XML based command protocol
  * @WWAN_PORT_XMMRPC: Control protocol for Intel XMM modems
+ * @WWAN_PORT_FASTBOOT: Fastboot protocol control
  *
  * @WWAN_PORT_MAX: Highest supported port types
  * @WWAN_PORT_UNKNOWN: Special value to indicate an unknown port type
@@ -28,6 +29,7 @@ enum wwan_port_type {
 	WWAN_PORT_QCDM,
 	WWAN_PORT_FIREHOSE,
 	WWAN_PORT_XMMRPC,
+	WWAN_PORT_FASTBOOT,
 
 	/* Add new port types above this line */
 
-- 
2.34.1

[net-next v3 2/3] net: wwan: t7xx: Add sysfs attribute for device state machine

[Jinjian Song]

From: Jinjian Song <jinjian.song@fibocom.com>

Add support for userspace to get the device mode,
e.g., reset/ready/fastboot mode.

Signed-off-by: Jinjian Song <jinjian.song@fibocom.com>
---
v3:
 * no change 
v2:
 * optimizing using goto label in t7xx_pci_probe
---
 drivers/net/wwan/t7xx/t7xx_modem_ops.c     |  1 +
 drivers/net/wwan/t7xx/t7xx_pci.c           | 85 +++++++++++++++++++++-
 drivers/net/wwan/t7xx/t7xx_pci.h           | 11 +++
 drivers/net/wwan/t7xx/t7xx_state_monitor.c |  1 +
 4 files changed, 94 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wwan/t7xx/t7xx_modem_ops.c b/drivers/net/wwan/t7xx/t7xx_modem_ops.c
index 24e7d491468e..ae4578905a8d 100644
--- a/drivers/net/wwan/t7xx/t7xx_modem_ops.c
+++ b/drivers/net/wwan/t7xx/t7xx_modem_ops.c
@@ -192,6 +192,7 @@ static irqreturn_t t7xx_rgu_isr_thread(int irq, void *data)
 {
 	struct t7xx_pci_dev *t7xx_dev = data;
 
+	atomic_set(&t7xx_dev->mode, T7XX_RESET);
 	msleep(RGU_RESET_DELAY_MS);
 	t7xx_reset_device_via_pmic(t7xx_dev);
 	return IRQ_HANDLED;
diff --git a/drivers/net/wwan/t7xx/t7xx_pci.c b/drivers/net/wwan/t7xx/t7xx_pci.c
index 91256e005b84..d5f6a8638aba 100644
--- a/drivers/net/wwan/t7xx/t7xx_pci.c
+++ b/drivers/net/wwan/t7xx/t7xx_pci.c
@@ -52,6 +52,68 @@
 #define PM_RESOURCE_POLL_TIMEOUT_US	10000
 #define PM_RESOURCE_POLL_STEP_US	100
 
+static ssize_t t7xx_mode_store(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct pci_dev *pdev;
+	struct t7xx_pci_dev *t7xx_dev;
+
+	pdev = to_pci_dev(dev);
+	t7xx_dev = pci_get_drvdata(pdev);
+	if (!t7xx_dev)
+		return -ENODEV;
+
+	atomic_set(&t7xx_dev->mode, T7XX_FASTBOOT_DL_SWITCHING);
+	return count;
+};
+
+static ssize_t t7xx_mode_show(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	enum t7xx_mode mode = T7XX_UNKNOWN;
+	struct pci_dev *pdev;
+	struct t7xx_pci_dev *t7xx_dev;
+
+	pdev = to_pci_dev(dev);
+	t7xx_dev = pci_get_drvdata(pdev);
+	if (!t7xx_dev)
+		return -ENODEV;
+
+	mode = atomic_read(&t7xx_dev->mode);
+	switch (mode) {
+	case T7XX_READY:
+		return sprintf(buf, "T7XX_MODEM_READY\n");
+
+	case T7XX_RESET:
+		return sprintf(buf, "T7XX_MODEM_RESET\n");
+
+	case T7XX_FASTBOOT_DL_SWITCHING:
+		return sprintf(buf, "T7XX_MODEM_FASTBOOT_DL_SWITCHING\n");
+
+	case T7XX_FASTBOOT_DL_MODE:
+		return sprintf(buf, "T7XX_MODEM_FASTBOOT_DL_MODE\n");
+
+	case T7XX_FASTBOOT_DUMP_MODE:
+		return sprintf(buf, "T7XX_MODEM_FASTBOOT_DUMP_MODE\n");
+
+	default:
+		return sprintf(buf, "T7XX_UNKNOWN\n");
+	}
+}
+
+static DEVICE_ATTR_RW(t7xx_mode);
+
+static struct attribute *t7xx_mode_attr[] = {
+	&dev_attr_t7xx_mode.attr,
+	NULL
+};
+
+static const struct attribute_group t7xx_mode_attribute_group = {
+	.attrs = t7xx_mode_attr,
+};
+
 enum t7xx_pm_state {
 	MTK_PM_EXCEPTION,
 	MTK_PM_INIT,		/* Device initialized, but handshake not completed */
@@ -729,16 +791,28 @@ static int t7xx_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 	t7xx_pcie_mac_interrupts_dis(t7xx_dev);
 
+	ret = sysfs_create_group(&t7xx_dev->pdev->dev.kobj,
+				 &t7xx_mode_attribute_group);
+	if (ret)
+		goto err_md_exit;
+
 	ret = t7xx_interrupt_init(t7xx_dev);
-	if (ret) {
-		t7xx_md_exit(t7xx_dev);
-		return ret;
-	}
+	if (ret)
+		goto err_remove_group;
+
 
 	t7xx_pcie_mac_set_int(t7xx_dev, MHCCIF_INT);
 	t7xx_pcie_mac_interrupts_en(t7xx_dev);
 
 	return 0;
+
+err_remove_group:
+	sysfs_remove_group(&t7xx_dev->pdev->dev.kobj,
+			   &t7xx_mode_attribute_group);
+
+err_md_exit:
+	t7xx_md_exit(t7xx_dev);
+	return ret;
 }
 
 static void t7xx_pci_remove(struct pci_dev *pdev)
@@ -747,6 +821,9 @@ static void t7xx_pci_remove(struct pci_dev *pdev)
 	int i;
 
 	t7xx_dev = pci_get_drvdata(pdev);
+
+	sysfs_remove_group(&t7xx_dev->pdev->dev.kobj,
+			   &t7xx_mode_attribute_group);
 	t7xx_md_exit(t7xx_dev);
 
 	for (i = 0; i < EXT_INT_NUM; i++) {
diff --git a/drivers/net/wwan/t7xx/t7xx_pci.h b/drivers/net/wwan/t7xx/t7xx_pci.h
index f08f1ab74469..fcd44e2d0a46 100644
--- a/drivers/net/wwan/t7xx/t7xx_pci.h
+++ b/drivers/net/wwan/t7xx/t7xx_pci.h
@@ -43,6 +43,15 @@ struct t7xx_addr_base {
 
 typedef irqreturn_t (*t7xx_intr_callback)(int irq, void *param);
 
+enum t7xx_mode {
+	T7XX_UNKNOWN,
+	T7XX_READY,
+	T7XX_RESET,
+	T7XX_FASTBOOT_DL_SWITCHING,
+	T7XX_FASTBOOT_DL_MODE,
+	T7XX_FASTBOOT_DUMP_MODE
+};
+
 /* struct t7xx_pci_dev - MTK device context structure
  * @intr_handler: array of handler function for request_threaded_irq
  * @intr_thread: array of thread_fn for request_threaded_irq
@@ -59,6 +68,7 @@ typedef irqreturn_t (*t7xx_intr_callback)(int irq, void *param);
  * @md_pm_lock: protects PCIe sleep lock
  * @sleep_disable_count: PCIe L1.2 lock counter
  * @sleep_lock_acquire: indicates that sleep has been disabled
+ * @mode: indicates the device mode
  */
 struct t7xx_pci_dev {
 	t7xx_intr_callback	intr_handler[EXT_INT_NUM];
@@ -82,6 +92,7 @@ struct t7xx_pci_dev {
 #ifdef CONFIG_WWAN_DEBUGFS
 	struct dentry		*debugfs_dir;
 #endif
+	atomic_t		mode;
 };
 
 enum t7xx_pm_id {
diff --git a/drivers/net/wwan/t7xx/t7xx_state_monitor.c b/drivers/net/wwan/t7xx/t7xx_state_monitor.c
index 0bc97430211b..23f54226aba0 100644
--- a/drivers/net/wwan/t7xx/t7xx_state_monitor.c
+++ b/drivers/net/wwan/t7xx/t7xx_state_monitor.c
@@ -272,6 +272,7 @@ static void fsm_routine_ready(struct t7xx_fsm_ctl *ctl)
 
 	ctl->curr_state = FSM_STATE_READY;
 	t7xx_fsm_broadcast_ready_state(ctl);
+	atomic_set(&md->t7xx_dev->mode, T7XX_READY);
 	t7xx_md_event_notify(md, FSM_READY);
 }
 
-- 
2.34.1

[net-next v3 3/3] net: wwan: t7xx: Add fastboot WWAN port

[Jinjian Song]

From: Jinjian Song <jinjian.song@fibocom.com>

To support cases such as firmware update or core dump, the t7xx
device is capable of signaling the host that a special port needs
to be created before the handshake phase.

Add the infrastructure required to create the early ports which
also requires a different configuration of CLDMA queues.

On early detection of wwan device in fastboot mode, driver sets
up CLDMA0 HW tx/rx queues for raw data transfer and then create
fastboot port to userspace.

Signed-off-by: Jinjian Song <jinjian.song@fibocom.com>
---
v3:
 * no change
v2:
 * no change
---
 drivers/net/wwan/t7xx/Makefile             |   1 +
 drivers/net/wwan/t7xx/t7xx_hif_cldma.c     |  47 +++++--
 drivers/net/wwan/t7xx/t7xx_hif_cldma.h     |  18 ++-
 drivers/net/wwan/t7xx/t7xx_modem_ops.c     |   4 +-
 drivers/net/wwan/t7xx/t7xx_pci.c           |   3 +-
 drivers/net/wwan/t7xx/t7xx_port.h          |   4 +
 drivers/net/wwan/t7xx/t7xx_port_fastboot.c | 155 +++++++++++++++++++++
 drivers/net/wwan/t7xx/t7xx_port_proxy.c    |  89 ++++++++++--
 drivers/net/wwan/t7xx/t7xx_port_proxy.h    |  12 ++
 drivers/net/wwan/t7xx/t7xx_port_wwan.c     |   5 +-
 drivers/net/wwan/t7xx/t7xx_reg.h           |  28 +++-
 drivers/net/wwan/t7xx/t7xx_state_monitor.c | 124 ++++++++++++++---
 drivers/net/wwan/t7xx/t7xx_state_monitor.h |   1 +
 13 files changed, 437 insertions(+), 54 deletions(-)
 create mode 100644 drivers/net/wwan/t7xx/t7xx_port_fastboot.c

diff --git a/drivers/net/wwan/t7xx/Makefile b/drivers/net/wwan/t7xx/Makefile
index 2652cd00504e..ddf03efe388a 100644
--- a/drivers/net/wwan/t7xx/Makefile
+++ b/drivers/net/wwan/t7xx/Makefile
@@ -11,6 +11,7 @@ mtk_t7xx-y:=	t7xx_pci.o \
 		t7xx_port_proxy.o  \
 		t7xx_port_ctrl_msg.o \
 		t7xx_port_wwan.o \
+		t7xx_port_fastboot.o \
 		t7xx_hif_dpmaif.o  \
 		t7xx_hif_dpmaif_tx.o \
 		t7xx_hif_dpmaif_rx.o  \
diff --git a/drivers/net/wwan/t7xx/t7xx_hif_cldma.c b/drivers/net/wwan/t7xx/t7xx_hif_cldma.c
index cc70360364b7..abc41a7089fa 100644
--- a/drivers/net/wwan/t7xx/t7xx_hif_cldma.c
+++ b/drivers/net/wwan/t7xx/t7xx_hif_cldma.c
@@ -57,8 +57,6 @@
 #define CHECK_Q_STOP_TIMEOUT_US		1000000
 #define CHECK_Q_STOP_STEP_US		10000
 
-#define CLDMA_JUMBO_BUFF_SZ		(63 * 1024 + sizeof(struct ccci_header))
-
 static void md_cd_queue_struct_reset(struct cldma_queue *queue, struct cldma_ctrl *md_ctrl,
 				     enum mtk_txrx tx_rx, unsigned int index)
 {
@@ -161,7 +159,7 @@ static int t7xx_cldma_gpd_rx_from_q(struct cldma_queue *queue, int budget, bool
 		skb_reset_tail_pointer(skb);
 		skb_put(skb, le16_to_cpu(gpd->data_buff_len));
 
-		ret = md_ctrl->recv_skb(queue, skb);
+		ret = queue->recv_skb(queue, skb);
 		/* Break processing, will try again later */
 		if (ret < 0)
 			return ret;
@@ -897,13 +895,13 @@ static void t7xx_cldma_hw_start_send(struct cldma_ctrl *md_ctrl, int qno,
 
 /**
  * t7xx_cldma_set_recv_skb() - Set the callback to handle RX packets.
- * @md_ctrl: CLDMA context structure.
+ * @queue: CLDMA queue.
  * @recv_skb: Receiving skb callback.
  */
-void t7xx_cldma_set_recv_skb(struct cldma_ctrl *md_ctrl,
+void t7xx_cldma_set_recv_skb(struct cldma_queue *queue,
 			     int (*recv_skb)(struct cldma_queue *queue, struct sk_buff *skb))
 {
-	md_ctrl->recv_skb = recv_skb;
+	queue->recv_skb = recv_skb;
 }
 
 /**
@@ -993,6 +991,28 @@ int t7xx_cldma_send_skb(struct cldma_ctrl *md_ctrl, int qno, struct sk_buff *skb
 	return ret;
 }
 
+static void t7xx_cldma_adjust_config(struct cldma_ctrl *md_ctrl, enum cldma_cfg cfg_id)
+{
+	int qno;
+
+	for (qno = 0; qno < CLDMA_RXQ_NUM; qno++) {
+		md_ctrl->rx_ring[qno].pkt_size = CLDMA_SHARED_Q_BUFF_SZ;
+		t7xx_cldma_set_recv_skb(&md_ctrl->rxq[qno], t7xx_port_proxy_recv_skb);
+	}
+
+	md_ctrl->rx_ring[CLDMA_RXQ_NUM - 1].pkt_size = CLDMA_JUMBO_BUFF_SZ;
+
+	for (qno = 0; qno < CLDMA_TXQ_NUM; qno++)
+		md_ctrl->tx_ring[qno].pkt_size = CLDMA_SHARED_Q_BUFF_SZ;
+
+	if (cfg_id == CLDMA_DEDICATED_Q_CFG) {
+		md_ctrl->tx_ring[CLDMA_Q_IDX_DUMP].pkt_size = CLDMA_DEDICATED_Q_BUFF_SZ;
+		md_ctrl->rx_ring[CLDMA_Q_IDX_DUMP].pkt_size = CLDMA_DEDICATED_Q_BUFF_SZ;
+		t7xx_cldma_set_recv_skb(&md_ctrl->rxq[CLDMA_Q_IDX_DUMP],
+					t7xx_port_proxy_recv_skb_from_dedicated_queue);
+	}
+}
+
 static int t7xx_cldma_late_init(struct cldma_ctrl *md_ctrl)
 {
 	char dma_pool_name[32];
@@ -1018,16 +1038,9 @@ static int t7xx_cldma_late_init(struct cldma_ctrl *md_ctrl)
 			dev_err(md_ctrl->dev, "control TX ring init fail\n");
 			goto err_free_tx_ring;
 		}
-
-		md_ctrl->tx_ring[i].pkt_size = CLDMA_MTU;
 	}
 
 	for (j = 0; j < CLDMA_RXQ_NUM; j++) {
-		md_ctrl->rx_ring[j].pkt_size = CLDMA_MTU;
-
-		if (j == CLDMA_RXQ_NUM - 1)
-			md_ctrl->rx_ring[j].pkt_size = CLDMA_JUMBO_BUFF_SZ;
-
 		ret = t7xx_cldma_rx_ring_init(md_ctrl, &md_ctrl->rx_ring[j]);
 		if (ret) {
 			dev_err(md_ctrl->dev, "Control RX ring init fail\n");
@@ -1094,6 +1107,7 @@ int t7xx_cldma_alloc(enum cldma_id hif_id, struct t7xx_pci_dev *t7xx_dev)
 {
 	struct device *dev = &t7xx_dev->pdev->dev;
 	struct cldma_ctrl *md_ctrl;
+	int qno;
 
 	md_ctrl = devm_kzalloc(dev, sizeof(*md_ctrl), GFP_KERNEL);
 	if (!md_ctrl)
@@ -1102,7 +1116,9 @@ int t7xx_cldma_alloc(enum cldma_id hif_id, struct t7xx_pci_dev *t7xx_dev)
 	md_ctrl->t7xx_dev = t7xx_dev;
 	md_ctrl->dev = dev;
 	md_ctrl->hif_id = hif_id;
-	md_ctrl->recv_skb = t7xx_cldma_default_recv_skb;
+	for (qno = 0; qno < CLDMA_RXQ_NUM; qno++)
+		md_ctrl->rxq[qno].recv_skb = t7xx_cldma_default_recv_skb;
+
 	t7xx_hw_info_init(md_ctrl);
 	t7xx_dev->md->md_ctrl[hif_id] = md_ctrl;
 	return 0;
@@ -1332,9 +1348,10 @@ int t7xx_cldma_init(struct cldma_ctrl *md_ctrl)
 	return -ENOMEM;
 }
 
-void t7xx_cldma_switch_cfg(struct cldma_ctrl *md_ctrl)
+void t7xx_cldma_switch_cfg(struct cldma_ctrl *md_ctrl, enum cldma_cfg cfg_id)
 {
 	t7xx_cldma_late_release(md_ctrl);
+	t7xx_cldma_adjust_config(md_ctrl, cfg_id);
 	t7xx_cldma_late_init(md_ctrl);
 }
 
diff --git a/drivers/net/wwan/t7xx/t7xx_hif_cldma.h b/drivers/net/wwan/t7xx/t7xx_hif_cldma.h
index 4410bac6993a..5453cfecbe19 100644
--- a/drivers/net/wwan/t7xx/t7xx_hif_cldma.h
+++ b/drivers/net/wwan/t7xx/t7xx_hif_cldma.h
@@ -31,6 +31,10 @@
 #include "t7xx_cldma.h"
 #include "t7xx_pci.h"
 
+#define CLDMA_JUMBO_BUFF_SZ		(63 * 1024 + sizeof(struct ccci_header))
+#define CLDMA_SHARED_Q_BUFF_SZ		3584
+#define CLDMA_DEDICATED_Q_BUFF_SZ	2048
+
 /**
  * enum cldma_id - Identifiers for CLDMA HW units.
  * @CLDMA_ID_MD: Modem control channel.
@@ -55,6 +59,11 @@ struct cldma_gpd {
 	__le16 not_used2;
 };
 
+enum cldma_cfg {
+	CLDMA_SHARED_Q_CFG,
+	CLDMA_DEDICATED_Q_CFG,
+};
+
 struct cldma_request {
 	struct cldma_gpd *gpd;	/* Virtual address for CPU */
 	dma_addr_t gpd_addr;	/* Physical address for DMA */
@@ -82,6 +91,7 @@ struct cldma_queue {
 	wait_queue_head_t req_wq;	/* Only for TX */
 	struct workqueue_struct *worker;
 	struct work_struct cldma_work;
+	int (*recv_skb)(struct cldma_queue *queue, struct sk_buff *skb);
 };
 
 struct cldma_ctrl {
@@ -101,24 +111,22 @@ struct cldma_ctrl {
 	struct md_pm_entity *pm_entity;
 	struct t7xx_cldma_hw hw_info;
 	bool is_late_init;
-	int (*recv_skb)(struct cldma_queue *queue, struct sk_buff *skb);
 };
 
+#define CLDMA_Q_IDX_DUMP 1
 #define GPD_FLAGS_HWO		BIT(0)
 #define GPD_FLAGS_IOC		BIT(7)
 #define GPD_DMAPOOL_ALIGN	16
 
-#define CLDMA_MTU		3584	/* 3.5kB */
-
 int t7xx_cldma_alloc(enum cldma_id hif_id, struct t7xx_pci_dev *t7xx_dev);
 void t7xx_cldma_hif_hw_init(struct cldma_ctrl *md_ctrl);
 int t7xx_cldma_init(struct cldma_ctrl *md_ctrl);
 void t7xx_cldma_exit(struct cldma_ctrl *md_ctrl);
-void t7xx_cldma_switch_cfg(struct cldma_ctrl *md_ctrl);
+void t7xx_cldma_switch_cfg(struct cldma_ctrl *md_ctrl, enum cldma_cfg cfg_id);
 void t7xx_cldma_start(struct cldma_ctrl *md_ctrl);
 int t7xx_cldma_stop(struct cldma_ctrl *md_ctrl);
 void t7xx_cldma_reset(struct cldma_ctrl *md_ctrl);
-void t7xx_cldma_set_recv_skb(struct cldma_ctrl *md_ctrl,
+void t7xx_cldma_set_recv_skb(struct cldma_queue *queue,
 			     int (*recv_skb)(struct cldma_queue *queue, struct sk_buff *skb));
 int t7xx_cldma_send_skb(struct cldma_ctrl *md_ctrl, int qno, struct sk_buff *skb);
 void t7xx_cldma_stop_all_qs(struct cldma_ctrl *md_ctrl, enum mtk_txrx tx_rx);
diff --git a/drivers/net/wwan/t7xx/t7xx_modem_ops.c b/drivers/net/wwan/t7xx/t7xx_modem_ops.c
index ae4578905a8d..fd2e9d085bea 100644
--- a/drivers/net/wwan/t7xx/t7xx_modem_ops.c
+++ b/drivers/net/wwan/t7xx/t7xx_modem_ops.c
@@ -530,7 +530,7 @@ static void t7xx_md_hk_wq(struct work_struct *work)
 
 	/* Clear the HS2 EXIT event appended in core_reset() */
 	t7xx_fsm_clr_event(ctl, FSM_EVENT_MD_HS2_EXIT);
-	t7xx_cldma_switch_cfg(md->md_ctrl[CLDMA_ID_MD]);
+	t7xx_cldma_switch_cfg(md->md_ctrl[CLDMA_ID_MD], CLDMA_SHARED_Q_CFG);
 	t7xx_cldma_start(md->md_ctrl[CLDMA_ID_MD]);
 	t7xx_fsm_broadcast_state(ctl, MD_STATE_WAITING_FOR_HS2);
 	md->core_md.handshake_ongoing = true;
@@ -545,7 +545,7 @@ static void t7xx_ap_hk_wq(struct work_struct *work)
 	 /* Clear the HS2 EXIT event appended in t7xx_core_reset(). */
 	t7xx_fsm_clr_event(ctl, FSM_EVENT_AP_HS2_EXIT);
 	t7xx_cldma_stop(md->md_ctrl[CLDMA_ID_AP]);
-	t7xx_cldma_switch_cfg(md->md_ctrl[CLDMA_ID_AP]);
+	t7xx_cldma_switch_cfg(md->md_ctrl[CLDMA_ID_AP], CLDMA_SHARED_Q_CFG);
 	t7xx_cldma_start(md->md_ctrl[CLDMA_ID_AP]);
 	md->core_ap.handshake_ongoing = true;
 	t7xx_core_hk_handler(md, &md->core_ap, ctl, FSM_EVENT_AP_HS2, FSM_EVENT_AP_HS2_EXIT);
diff --git a/drivers/net/wwan/t7xx/t7xx_pci.c b/drivers/net/wwan/t7xx/t7xx_pci.c
index d5f6a8638aba..f51e5e2b41e1 100644
--- a/drivers/net/wwan/t7xx/t7xx_pci.c
+++ b/drivers/net/wwan/t7xx/t7xx_pci.c
@@ -170,7 +170,8 @@ static int t7xx_pci_pm_init(struct t7xx_pci_dev *t7xx_dev)
 	pm_runtime_set_autosuspend_delay(&pdev->dev, PM_AUTOSUSPEND_MS);
 	pm_runtime_use_autosuspend(&pdev->dev);
 
-	return t7xx_wait_pm_config(t7xx_dev);
+	t7xx_wait_pm_config(t7xx_dev);
+	return 0;
 }
 
 void t7xx_pci_pm_init_late(struct t7xx_pci_dev *t7xx_dev)
diff --git a/drivers/net/wwan/t7xx/t7xx_port.h b/drivers/net/wwan/t7xx/t7xx_port.h
index 4ae8a00a8532..09acb1ef144d 100644
--- a/drivers/net/wwan/t7xx/t7xx_port.h
+++ b/drivers/net/wwan/t7xx/t7xx_port.h
@@ -75,6 +75,8 @@ enum port_ch {
 	PORT_CH_DSS6_TX = 0x20df,
 	PORT_CH_DSS7_RX = 0x20e0,
 	PORT_CH_DSS7_TX = 0x20e1,
+
+	PORT_CH_ID_UNIMPORTANT = 0xffff,
 };
 
 struct t7xx_port;
@@ -135,9 +137,11 @@ struct t7xx_port {
 	};
 };
 
+int t7xx_get_port_mtu(struct t7xx_port *port);
 struct sk_buff *t7xx_port_alloc_skb(int payload);
 struct sk_buff *t7xx_ctrl_alloc_skb(int payload);
 int t7xx_port_enqueue_skb(struct t7xx_port *port, struct sk_buff *skb);
+int t7xx_port_send_raw_skb(struct t7xx_port *port, struct sk_buff *skb);
 int t7xx_port_send_skb(struct t7xx_port *port, struct sk_buff *skb, unsigned int pkt_header,
 		       unsigned int ex_msg);
 int t7xx_port_send_ctl_skb(struct t7xx_port *port, struct sk_buff *skb, unsigned int msg,
diff --git a/drivers/net/wwan/t7xx/t7xx_port_fastboot.c b/drivers/net/wwan/t7xx/t7xx_port_fastboot.c
new file mode 100644
index 000000000000..1b7936b8eef0
--- /dev/null
+++ b/drivers/net/wwan/t7xx/t7xx_port_fastboot.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023, Fibocom Wireless Inc.
+ *
+ * Authors:
+ *  Jinjian Song <jinjian.song@fibocom.com>
+ */
+
+#include <linux/atomic.h>
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/minmax.h>
+#include <linux/skbuff.h>
+#include <linux/spinlock.h>
+#include <linux/wwan.h>
+
+#include "t7xx_port.h"
+#include "t7xx_port_proxy.h"
+#include "t7xx_state_monitor.h"
+
+static int t7xx_port_ctrl_start(struct wwan_port *port)
+{
+	struct t7xx_port *port_mtk = wwan_port_get_drvdata(port);
+
+	if (atomic_read(&port_mtk->usage_cnt))
+		return -EBUSY;
+
+	atomic_inc(&port_mtk->usage_cnt);
+	return 0;
+}
+
+static void t7xx_port_ctrl_stop(struct wwan_port *port)
+{
+	struct t7xx_port *port_mtk = wwan_port_get_drvdata(port);
+
+	atomic_dec(&port_mtk->usage_cnt);
+}
+
+static int t7xx_port_ctrl_tx(struct wwan_port *port, struct sk_buff *skb)
+{
+	struct t7xx_port *port_private = wwan_port_get_drvdata(port);
+	struct sk_buff *cur = skb, *cloned;
+	size_t actual, len, offset = 0;
+	int ret;
+	int txq_mtu;
+
+	if (!port_private->chan_enable)
+		return -EINVAL;
+
+	txq_mtu = t7xx_get_port_mtu(port_private);
+	if (txq_mtu < 0)
+		return -EINVAL;
+
+	actual = cur->len;
+	while (actual) {
+		len = min_t(size_t, actual, txq_mtu);
+		cloned = __dev_alloc_skb(len, GFP_KERNEL);
+		if (!cloned)
+			return -ENOMEM;
+
+		skb_put_data(cloned, cur->data + offset, len);
+
+		ret = t7xx_port_send_raw_skb(port_private, cloned);
+		if (ret) {
+			dev_kfree_skb(cloned);
+			dev_err(port_private->dev, "Write error on fastboot port, %d\n", ret);
+			break;
+		}
+		offset += len;
+		actual -= len;
+	}
+
+	dev_kfree_skb(skb);
+	return 0;
+}
+
+static const struct wwan_port_ops wwan_ops = {
+	.start = t7xx_port_ctrl_start,
+	.stop = t7xx_port_ctrl_stop,
+	.tx = t7xx_port_ctrl_tx,
+};
+
+static int t7xx_port_fastboot_init(struct t7xx_port *port)
+{
+	const struct t7xx_port_conf *port_conf = port->port_conf;
+	unsigned int header_len = sizeof(struct ccci_header), mtu;
+	struct wwan_port_caps caps;
+
+	port->rx_length_th = RX_QUEUE_MAXLEN;
+
+	if (!port->wwan.wwan_port) {
+		mtu = t7xx_get_port_mtu(port);
+		caps.frag_len = mtu - header_len;
+		caps.headroom_len = header_len;
+		port->wwan.wwan_port = wwan_create_port(port->dev, port_conf->port_type,
+							&wwan_ops, &caps, port);
+		if (IS_ERR(port->wwan.wwan_port))
+			dev_err(port->dev, "Unable to create WWWAN port %s", port_conf->name);
+	}
+
+	return 0;
+}
+
+static void t7xx_port_fastboot_uninit(struct t7xx_port *port)
+{
+	if (!port->wwan.wwan_port)
+		return;
+
+	port->rx_length_th = 0;
+	wwan_remove_port(port->wwan.wwan_port);
+	port->wwan.wwan_port = NULL;
+}
+
+static int t7xx_port_fastboot_recv_skb(struct t7xx_port *port, struct sk_buff *skb)
+{
+	if (!atomic_read(&port->usage_cnt) || !port->chan_enable) {
+		const struct t7xx_port_conf *port_conf = port->port_conf;
+
+		dev_kfree_skb_any(skb);
+		dev_err_ratelimited(port->dev, "Port %s is not opened, drop packets\n",
+				    port_conf->name);
+		/* Dropping skb, caller should not access skb.*/
+		return 0;
+	}
+
+	wwan_port_rx(port->wwan.wwan_port, skb);
+
+	return 0;
+}
+
+static int t7xx_port_fastboot_enable_chl(struct t7xx_port *port)
+{
+	spin_lock(&port->port_update_lock);
+	port->chan_enable = true;
+	spin_unlock(&port->port_update_lock);
+
+	return 0;
+}
+
+static int t7xx_port_fastboot_disable_chl(struct t7xx_port *port)
+{
+	spin_lock(&port->port_update_lock);
+	port->chan_enable = false;
+	spin_unlock(&port->port_update_lock);
+
+	return 0;
+}
+
+struct port_ops fastboot_port_ops = {
+	.init = t7xx_port_fastboot_init,
+	.recv_skb = t7xx_port_fastboot_recv_skb,
+	.uninit = t7xx_port_fastboot_uninit,
+	.enable_chl = t7xx_port_fastboot_enable_chl,
+	.disable_chl = t7xx_port_fastboot_disable_chl,
+};
diff --git a/drivers/net/wwan/t7xx/t7xx_port_proxy.c b/drivers/net/wwan/t7xx/t7xx_port_proxy.c
index 274846d39fbf..0525a70acc81 100644
--- a/drivers/net/wwan/t7xx/t7xx_port_proxy.c
+++ b/drivers/net/wwan/t7xx/t7xx_port_proxy.c
@@ -100,6 +100,21 @@ static const struct t7xx_port_conf t7xx_port_conf[] = {
 	},
 };
 
+static struct t7xx_port_conf t7xx_early_port_conf[] = {
+	{
+		.tx_ch = PORT_CH_ID_UNIMPORTANT,
+		.rx_ch = PORT_CH_ID_UNIMPORTANT,
+		.txq_index = CLDMA_Q_IDX_DUMP,
+		.rxq_index = CLDMA_Q_IDX_DUMP,
+		.txq_exp_index = CLDMA_Q_IDX_DUMP,
+		.rxq_exp_index = CLDMA_Q_IDX_DUMP,
+		.path_id = CLDMA_ID_AP,
+		.ops = &fastboot_port_ops,
+		.name = "FASTBOOT",
+		.port_type = WWAN_PORT_FASTBOOT,
+	},
+};
+
 static struct t7xx_port *t7xx_proxy_get_port_by_ch(struct port_proxy *port_prox, enum port_ch ch)
 {
 	const struct t7xx_port_conf *port_conf;
@@ -214,7 +229,17 @@ int t7xx_port_enqueue_skb(struct t7xx_port *port, struct sk_buff *skb)
 	return 0;
 }
 
-static int t7xx_port_send_raw_skb(struct t7xx_port *port, struct sk_buff *skb)
+int t7xx_get_port_mtu(struct t7xx_port *port)
+{
+	enum cldma_id path_id = port->port_conf->path_id;
+	int tx_qno = t7xx_port_get_queue_no(port);
+	struct cldma_ctrl *md_ctrl;
+
+	md_ctrl = port->t7xx_dev->md->md_ctrl[path_id];
+	return md_ctrl->tx_ring[tx_qno].pkt_size;
+}
+
+int t7xx_port_send_raw_skb(struct t7xx_port *port, struct sk_buff *skb)
 {
 	enum cldma_id path_id = port->port_conf->path_id;
 	struct cldma_ctrl *md_ctrl;
@@ -329,6 +354,30 @@ static void t7xx_proxy_setup_ch_mapping(struct port_proxy *port_prox)
 	}
 }
 
+int t7xx_port_proxy_recv_skb_from_dedicated_queue(struct cldma_queue *queue, struct sk_buff *skb)
+{
+	struct t7xx_pci_dev *t7xx_dev = queue->md_ctrl->t7xx_dev;
+	struct port_proxy *port_prox = t7xx_dev->md->port_prox;
+	const struct t7xx_port_conf *port_conf;
+	struct t7xx_port *port;
+	int ret;
+
+	port = &port_prox->ports[0];
+	if (WARN_ON_ONCE(port->port_conf->rxq_index != queue->index)) {
+		dev_kfree_skb_any(skb);
+		return -EINVAL;
+	}
+
+	port_conf = port->port_conf;
+	ret = port_conf->ops->recv_skb(port, skb);
+	if (ret < 0 && ret != -ENOBUFS) {
+		dev_err(port->dev, "drop on RX ch %d, %d\n", port_conf->rx_ch, ret);
+		dev_kfree_skb_any(skb);
+	}
+
+	return ret;
+}
+
 static struct t7xx_port *t7xx_port_proxy_find_port(struct t7xx_pci_dev *t7xx_dev,
 						   struct cldma_queue *queue, u16 channel)
 {
@@ -359,7 +408,7 @@ static struct t7xx_port *t7xx_port_proxy_find_port(struct t7xx_pci_dev *t7xx_dev
  ** 0		- Packet consumed.
  ** -ERROR	- Failed to process skb.
  */
-static int t7xx_port_proxy_recv_skb(struct cldma_queue *queue, struct sk_buff *skb)
+int t7xx_port_proxy_recv_skb(struct cldma_queue *queue, struct sk_buff *skb)
 {
 	struct ccci_header *ccci_h = (struct ccci_header *)skb->data;
 	struct t7xx_pci_dev *t7xx_dev = queue->md_ctrl->t7xx_dev;
@@ -451,13 +500,39 @@ static void t7xx_proxy_init_all_ports(struct t7xx_modem *md)
 	t7xx_proxy_setup_ch_mapping(port_prox);
 }
 
+void t7xx_port_proxy_set_cfg(struct t7xx_modem *md, enum port_cfg_id cfg_id)
+{
+	struct port_proxy *port_prox = md->port_prox;
+	const struct t7xx_port_conf *port_conf;
+	u32 port_count;
+	int i;
+
+	t7xx_port_proxy_uninit(port_prox);
+
+	if (cfg_id == PORT_CFG_ID_EARLY) {
+		port_conf = t7xx_early_port_conf;
+		port_count = ARRAY_SIZE(t7xx_early_port_conf);
+	} else {
+		port_conf = t7xx_port_conf;
+		port_count = ARRAY_SIZE(t7xx_port_conf);
+	}
+
+	for (i = 0; i < port_count; i++)
+		port_prox->ports[i].port_conf = &port_conf[i];
+
+	port_prox->cfg_id = cfg_id;
+	port_prox->port_count = port_count;
+	t7xx_proxy_init_all_ports(md);
+}
+
 static int t7xx_proxy_alloc(struct t7xx_modem *md)
 {
+	unsigned int early_port_count = ARRAY_SIZE(t7xx_early_port_conf);
 	unsigned int port_count = ARRAY_SIZE(t7xx_port_conf);
 	struct device *dev = &md->t7xx_dev->pdev->dev;
 	struct port_proxy *port_prox;
-	int i;
 
+	port_count = max(port_count, early_port_count);
 	port_prox = devm_kzalloc(dev, sizeof(*port_prox) + sizeof(struct t7xx_port) * port_count,
 				 GFP_KERNEL);
 	if (!port_prox)
@@ -465,12 +540,8 @@ static int t7xx_proxy_alloc(struct t7xx_modem *md)
 
 	md->port_prox = port_prox;
 	port_prox->dev = dev;
+	t7xx_port_proxy_set_cfg(md, PORT_CFG_ID_EARLY);
 
-	for (i = 0; i < port_count; i++)
-		port_prox->ports[i].port_conf = &t7xx_port_conf[i];
-
-	port_prox->port_count = port_count;
-	t7xx_proxy_init_all_ports(md);
 	return 0;
 }
 
@@ -492,8 +563,6 @@ int t7xx_port_proxy_init(struct t7xx_modem *md)
 	if (ret)
 		return ret;
 
-	t7xx_cldma_set_recv_skb(md->md_ctrl[CLDMA_ID_AP], t7xx_port_proxy_recv_skb);
-	t7xx_cldma_set_recv_skb(md->md_ctrl[CLDMA_ID_MD], t7xx_port_proxy_recv_skb);
 	return 0;
 }
 
diff --git a/drivers/net/wwan/t7xx/t7xx_port_proxy.h b/drivers/net/wwan/t7xx/t7xx_port_proxy.h
index 81d059fbc0fb..0f40b4884dc0 100644
--- a/drivers/net/wwan/t7xx/t7xx_port_proxy.h
+++ b/drivers/net/wwan/t7xx/t7xx_port_proxy.h
@@ -31,11 +31,18 @@
 #define RX_QUEUE_MAXLEN		32
 #define CTRL_QUEUE_MAXLEN	16
 
+enum port_cfg_id {
+	PORT_CFG_ID_INVALID,
+	PORT_CFG_ID_NORMAL,
+	PORT_CFG_ID_EARLY,
+};
+
 struct port_proxy {
 	int			port_count;
 	struct list_head	rx_ch_ports[PORT_CH_ID_MASK + 1];
 	struct list_head	queue_ports[CLDMA_NUM][MTK_QUEUES];
 	struct device		*dev;
+	enum port_cfg_id	cfg_id;
 	struct t7xx_port	ports[];
 };
 
@@ -91,6 +98,8 @@ extern struct port_ops ctl_port_ops;
 extern struct port_ops t7xx_trace_port_ops;
 #endif
 
+extern struct port_ops fastboot_port_ops;
+
 void t7xx_port_proxy_reset(struct port_proxy *port_prox);
 void t7xx_port_proxy_uninit(struct port_proxy *port_prox);
 int t7xx_port_proxy_init(struct t7xx_modem *md);
@@ -98,5 +107,8 @@ void t7xx_port_proxy_md_status_notify(struct port_proxy *port_prox, unsigned int
 int t7xx_port_enum_msg_handler(struct t7xx_modem *md, void *msg);
 int t7xx_port_proxy_chl_enable_disable(struct port_proxy *port_prox, unsigned int ch_id,
 				       bool en_flag);
+void t7xx_port_proxy_set_cfg(struct t7xx_modem *md, enum port_cfg_id cfg_id);
+int t7xx_port_proxy_recv_skb(struct cldma_queue *queue, struct sk_buff *skb);
+int t7xx_port_proxy_recv_skb_from_dedicated_queue(struct cldma_queue *queue, struct sk_buff *skb);
 
 #endif /* __T7XX_PORT_PROXY_H__ */
diff --git a/drivers/net/wwan/t7xx/t7xx_port_wwan.c b/drivers/net/wwan/t7xx/t7xx_port_wwan.c
index 17389c8f6600..ddc20ddfa734 100644
--- a/drivers/net/wwan/t7xx/t7xx_port_wwan.c
+++ b/drivers/net/wwan/t7xx/t7xx_port_wwan.c
@@ -152,14 +152,15 @@ static int t7xx_port_wwan_disable_chl(struct t7xx_port *port)
 static void t7xx_port_wwan_md_state_notify(struct t7xx_port *port, unsigned int state)
 {
 	const struct t7xx_port_conf *port_conf = port->port_conf;
-	unsigned int header_len = sizeof(struct ccci_header);
+	unsigned int header_len = sizeof(struct ccci_header), mtu;
 	struct wwan_port_caps caps;
 
 	if (state != MD_STATE_READY)
 		return;
 
 	if (!port->wwan.wwan_port) {
-		caps.frag_len = CLDMA_MTU - header_len;
+		mtu = t7xx_get_port_mtu(port);
+		caps.frag_len = mtu - header_len;
 		caps.headroom_len = header_len;
 		port->wwan.wwan_port = wwan_create_port(port->dev, port_conf->port_type,
 							&wwan_ops, &caps, port);
diff --git a/drivers/net/wwan/t7xx/t7xx_reg.h b/drivers/net/wwan/t7xx/t7xx_reg.h
index c41d7d094c08..c76d2b3c162d 100644
--- a/drivers/net/wwan/t7xx/t7xx_reg.h
+++ b/drivers/net/wwan/t7xx/t7xx_reg.h
@@ -101,11 +101,33 @@ enum t7xx_pm_resume_state {
 	PM_RESUME_REG_STATE_L2_EXP,
 };
 
+enum host_event_e {
+	HOST_EVENT_INIT = 0,
+	FASTBOOT_DL_NOTIFY = 0x3,
+};
+
 #define T7XX_PCIE_MISC_DEV_STATUS		0x0d1c
-#define MISC_STAGE_MASK				GENMASK(2, 0)
-#define MISC_RESET_TYPE_PLDR			BIT(26)
 #define MISC_RESET_TYPE_FLDR			BIT(27)
-#define LINUX_STAGE				4
+#define MISC_RESET_TYPE_PLDR			BIT(26)
+#define MISC_LK_EVENT_MASK			GENMASK(11, 8)
+#define HOST_EVENT_MASK				GENMASK(31, 28)
+
+enum lk_event_id {
+	LK_EVENT_NORMAL = 0,
+	LK_EVENT_CREATE_PD_PORT = 1,
+	LK_EVENT_CREATE_POST_DL_PORT = 2,
+	LK_EVENT_RESET = 7,
+};
+
+#define MISC_STAGE_MASK				GENMASK(2, 0)
+
+enum t7xx_device_stage {
+	T7XX_DEV_STAGE_INIT = 0,
+	T7XX_DEV_STAGE_BROM_PRE = 1,
+	T7XX_DEV_STAGE_BROM_POST = 2,
+	T7XX_DEV_STAGE_LK = 3,
+	T7XX_DEV_STAGE_LINUX = 4,
+};
 
 #define T7XX_PCIE_RESOURCE_STATUS		0x0d28
 #define T7XX_PCIE_RESOURCE_STS_MSK		GENMASK(4, 0)
diff --git a/drivers/net/wwan/t7xx/t7xx_state_monitor.c b/drivers/net/wwan/t7xx/t7xx_state_monitor.c
index 23f54226aba0..a168bac1f40d 100644
--- a/drivers/net/wwan/t7xx/t7xx_state_monitor.c
+++ b/drivers/net/wwan/t7xx/t7xx_state_monitor.c
@@ -206,6 +206,55 @@ static void fsm_routine_exception(struct t7xx_fsm_ctl *ctl, struct t7xx_fsm_comm
 		fsm_finish_command(ctl, cmd, 0);
 }
 
+static void t7xx_host_event_notify(struct t7xx_modem *md, unsigned int event_id)
+{
+	u32 value;
+
+	value = ioread32(IREG_BASE(md->t7xx_dev) + T7XX_PCIE_MISC_DEV_STATUS);
+	value &= ~HOST_EVENT_MASK;
+	value |= FIELD_PREP(HOST_EVENT_MASK, event_id);
+	iowrite32(value, IREG_BASE(md->t7xx_dev) + T7XX_PCIE_MISC_DEV_STATUS);
+}
+
+static void t7xx_lk_stage_event_handling(struct t7xx_fsm_ctl *ctl, unsigned int status)
+{
+	struct t7xx_modem *md = ctl->md;
+	struct cldma_ctrl *md_ctrl;
+	enum lk_event_id lk_event;
+	struct device *dev;
+	struct t7xx_port *port;
+
+	dev = &md->t7xx_dev->pdev->dev;
+	lk_event = FIELD_GET(MISC_LK_EVENT_MASK, status);
+	switch (lk_event) {
+	case LK_EVENT_NORMAL:
+	case LK_EVENT_RESET:
+		break;
+
+	case LK_EVENT_CREATE_PD_PORT:
+	case LK_EVENT_CREATE_POST_DL_PORT:
+		md_ctrl = md->md_ctrl[CLDMA_ID_AP];
+		t7xx_cldma_hif_hw_init(md_ctrl);
+		t7xx_cldma_stop(md_ctrl);
+		t7xx_cldma_switch_cfg(md_ctrl, CLDMA_DEDICATED_Q_CFG);
+
+		port = &ctl->md->port_prox->ports[0];
+		port->port_conf->ops->enable_chl(port);
+
+		t7xx_cldma_start(md_ctrl);
+
+		if (lk_event == LK_EVENT_CREATE_POST_DL_PORT)
+			atomic_set(&md->t7xx_dev->mode, T7XX_FASTBOOT_DL_MODE);
+		else
+			atomic_set(&md->t7xx_dev->mode, T7XX_FASTBOOT_DUMP_MODE);
+		break;
+
+	default:
+		dev_err(dev, "Invalid LK event %d\n", lk_event);
+		break;
+	}
+}
+
 static int fsm_stopped_handler(struct t7xx_fsm_ctl *ctl)
 {
 	ctl->curr_state = FSM_STATE_STOPPED;
@@ -230,7 +279,9 @@ static void fsm_routine_stopping(struct t7xx_fsm_ctl *ctl, struct t7xx_fsm_comma
 	struct cldma_ctrl *md_ctrl;
 	int err;
 
-	if (ctl->curr_state == FSM_STATE_STOPPED || ctl->curr_state == FSM_STATE_STOPPING) {
+	if (ctl->curr_state == FSM_STATE_STOPPED ||
+	    ctl->curr_state == FSM_STATE_STOPPING ||
+	    ctl->md->rgu_irq_asserted) {
 		fsm_finish_command(ctl, cmd, -EINVAL);
 		return;
 	}
@@ -242,11 +293,16 @@ static void fsm_routine_stopping(struct t7xx_fsm_ctl *ctl, struct t7xx_fsm_comma
 	t7xx_fsm_broadcast_state(ctl, MD_STATE_WAITING_TO_STOP);
 	t7xx_cldma_stop(md_ctrl);
 
-	if (!ctl->md->rgu_irq_asserted) {
-		t7xx_mhccif_h2d_swint_trigger(t7xx_dev, H2D_CH_DRM_DISABLE_AP);
-		/* Wait for the DRM disable to take effect */
-		msleep(FSM_DRM_DISABLE_DELAY_MS);
+	if (atomic_read(&t7xx_dev->mode) == T7XX_FASTBOOT_DL_SWITCHING)
+		t7xx_host_event_notify(ctl->md, FASTBOOT_DL_NOTIFY);
 
+	t7xx_mhccif_h2d_swint_trigger(t7xx_dev, H2D_CH_DRM_DISABLE_AP);
+	/* Wait for the DRM disable to take effect */
+	msleep(FSM_DRM_DISABLE_DELAY_MS);
+
+	if (atomic_read(&t7xx_dev->mode) == T7XX_FASTBOOT_DL_SWITCHING) {
+		t7xx_mhccif_h2d_swint_trigger(t7xx_dev, H2D_CH_DEVICE_RESET);
+	} else {
 		err = t7xx_acpi_fldr_func(t7xx_dev);
 		if (err)
 			t7xx_mhccif_h2d_swint_trigger(t7xx_dev, H2D_CH_DEVICE_RESET);
@@ -318,7 +374,8 @@ static int fsm_routine_starting(struct t7xx_fsm_ctl *ctl)
 static void fsm_routine_start(struct t7xx_fsm_ctl *ctl, struct t7xx_fsm_command *cmd)
 {
 	struct t7xx_modem *md = ctl->md;
-	u32 dev_status;
+	struct device *dev;
+	u32 status;
 	int ret;
 
 	if (!md)
@@ -330,23 +387,57 @@ static void fsm_routine_start(struct t7xx_fsm_ctl *ctl, struct t7xx_fsm_command
 		return;
 	}
 
+	dev = &md->t7xx_dev->pdev->dev;
 	ctl->curr_state = FSM_STATE_PRE_START;
 	t7xx_md_event_notify(md, FSM_PRE_START);
 
-	ret = read_poll_timeout(ioread32, dev_status,
-				(dev_status & MISC_STAGE_MASK) == LINUX_STAGE, 20000, 2000000,
-				false, IREG_BASE(md->t7xx_dev) + T7XX_PCIE_MISC_DEV_STATUS);
+	ret = read_poll_timeout(ioread32, status,
+				((status & MISC_STAGE_MASK) == T7XX_DEV_STAGE_LINUX) ||
+				((status & MISC_STAGE_MASK) == T7XX_DEV_STAGE_LK), 100000,
+				20000000, false, IREG_BASE(md->t7xx_dev) +
+				T7XX_PCIE_MISC_DEV_STATUS);
+
 	if (ret) {
-		struct device *dev = &md->t7xx_dev->pdev->dev;
+		dev_err(dev, "read poll timeout %d\n", ret);
+		goto finish_command;
+	}
 
-		fsm_finish_command(ctl, cmd, -ETIMEDOUT);
-		dev_err(dev, "Invalid device status 0x%lx\n", dev_status & MISC_STAGE_MASK);
-		return;
+	if (status != ctl->prev_status || cmd->flag != 0) {
+		u32 stage = FIELD_GET(MISC_STAGE_MASK, status);
+
+		switch (stage) {
+		case T7XX_DEV_STAGE_INIT:
+		case T7XX_DEV_STAGE_BROM_PRE:
+		case T7XX_DEV_STAGE_BROM_POST:
+			dev_dbg(dev, "BROM_STAGE Entered\n");
+			ret = t7xx_fsm_append_cmd(ctl, FSM_CMD_START, 0);
+			break;
+
+		case T7XX_DEV_STAGE_LK:
+			dev_dbg(dev, "LK_STAGE Entered\n");
+			t7xx_lk_stage_event_handling(ctl, status);
+			break;
+
+		case T7XX_DEV_STAGE_LINUX:
+			dev_dbg(dev, "LINUX_STAGE Entered\n");
+			t7xx_mhccif_mask_clr(md->t7xx_dev, D2H_INT_PORT_ENUM |
+					     D2H_INT_ASYNC_MD_HK | D2H_INT_ASYNC_AP_HK);
+			if (cmd->flag == 0)
+				break;
+			t7xx_cldma_hif_hw_init(md->md_ctrl[CLDMA_ID_AP]);
+			t7xx_cldma_hif_hw_init(md->md_ctrl[CLDMA_ID_MD]);
+			t7xx_port_proxy_set_cfg(md, PORT_CFG_ID_NORMAL);
+			ret = fsm_routine_starting(ctl);
+			break;
+
+		default:
+			break;
+		}
+		ctl->prev_status = status;
 	}
 
-	t7xx_cldma_hif_hw_init(md->md_ctrl[CLDMA_ID_AP]);
-	t7xx_cldma_hif_hw_init(md->md_ctrl[CLDMA_ID_MD]);
-	fsm_finish_command(ctl, cmd, fsm_routine_starting(ctl));
+finish_command:
+	fsm_finish_command(ctl, cmd, ret);
 }
 
 static int fsm_main_thread(void *data)
@@ -518,6 +609,7 @@ void t7xx_fsm_reset(struct t7xx_modem *md)
 	fsm_flush_event_cmd_qs(ctl);
 	ctl->curr_state = FSM_STATE_STOPPED;
 	ctl->exp_flg = false;
+	ctl->prev_status = 0;
 }
 
 int t7xx_fsm_init(struct t7xx_modem *md)
diff --git a/drivers/net/wwan/t7xx/t7xx_state_monitor.h b/drivers/net/wwan/t7xx/t7xx_state_monitor.h
index b0b3662ae6d7..9421bbd2f117 100644
--- a/drivers/net/wwan/t7xx/t7xx_state_monitor.h
+++ b/drivers/net/wwan/t7xx/t7xx_state_monitor.h
@@ -96,6 +96,7 @@ struct t7xx_fsm_ctl {
 	bool			exp_flg;
 	spinlock_t		notifier_lock;		/* Protects notifier list */
 	struct list_head	notifier_list;
+	u32                     prev_status;
 };
 
 struct t7xx_fsm_event {
-- 
2.34.1

Re: [net-next v3 2/3] net: wwan: t7xx: Add sysfs attribute for device state machine

[Jakub Kicinski]

On Thu, 28 Dec 2023 17:44:10 +0800 Jinjian Song wrote:
> From: Jinjian Song <jinjian.song@fibocom.com>
> 
> Add support for userspace to get the device mode,
> e.g., reset/ready/fastboot mode.

We need some info under Documentation/ describing the file / attr
and how it's supposed to be used.

> diff --git a/drivers/net/wwan/t7xx/t7xx_modem_ops.c b/drivers/net/wwan/t7xx/t7xx_modem_ops.c
> index 24e7d491468e..ae4578905a8d 100644
> --- a/drivers/net/wwan/t7xx/t7xx_modem_ops.c
> +++ b/drivers/net/wwan/t7xx/t7xx_modem_ops.c
> @@ -192,6 +192,7 @@ static irqreturn_t t7xx_rgu_isr_thread(int irq, void *data)
>  {
>  	struct t7xx_pci_dev *t7xx_dev = data;
>  
> +	atomic_set(&t7xx_dev->mode, T7XX_RESET);

Why is ->mode atomic? There seem to be no RMW operations on it.
You can use READ_ONCE() / WRITE_ONCE() on a normal integer.

>  	msleep(RGU_RESET_DELAY_MS);
>  	t7xx_reset_device_via_pmic(t7xx_dev);
>  	return IRQ_HANDLED;
> diff --git a/drivers/net/wwan/t7xx/t7xx_pci.c b/drivers/net/wwan/t7xx/t7xx_pci.c
> index 91256e005b84..d5f6a8638aba 100644
> --- a/drivers/net/wwan/t7xx/t7xx_pci.c
> +++ b/drivers/net/wwan/t7xx/t7xx_pci.c
> @@ -52,6 +52,68 @@
>  #define PM_RESOURCE_POLL_TIMEOUT_US	10000
>  #define PM_RESOURCE_POLL_STEP_US	100
>  
> +static ssize_t t7xx_mode_store(struct device *dev,
> +			       struct device_attribute *attr,
> +			       const char *buf, size_t count)
> +{
> +	struct pci_dev *pdev;
> +	struct t7xx_pci_dev *t7xx_dev;
> +
> +	pdev = to_pci_dev(dev);
> +	t7xx_dev = pci_get_drvdata(pdev);
> +	if (!t7xx_dev)
> +		return -ENODEV;
> +
> +	atomic_set(&t7xx_dev->mode, T7XX_FASTBOOT_DL_SWITCHING);

This function doesn't use @buf at all. So whenever user does write()
to the file we set to SWITCHING? Shouldn't we narrow down the set
of accepted values to be able to add more functionality later?

> +	return count;
> +};

unnecessary semi-colon

Re: [net-next v3 3/3] net: wwan: t7xx: Add fastboot WWAN port

[Sergey Ryazanov]

Hello Jinjian,

thank you for sharing this implementation. I believe this patch requires 
further splitting since its hard to distinguish between generic changes 
and fastboot port introduction. And here a lot of changes to the common 
driver codebase. At least the ports configuration rework worth a 
dedicated patch and probably modem boot state tracking also requires a 
dedicated patch or should go to the modem state exporting patch.

Please find a few nitpicks below.

On 28.12.2023 11:44, Jinjian Song wrote:

[skipped]

> @@ -82,6 +91,7 @@ struct cldma_queue {
>   	wait_queue_head_t req_wq;	/* Only for TX */
>   	struct workqueue_struct *worker;
>   	struct work_struct cldma_work;
> +	int (*recv_skb)(struct cldma_queue *queue, struct sk_buff *skb);
>   };
>   
>   struct cldma_ctrl {
> @@ -101,24 +111,22 @@ struct cldma_ctrl {
>   	struct md_pm_entity *pm_entity;
>   	struct t7xx_cldma_hw hw_info;
>   	bool is_late_init;
> -	int (*recv_skb)(struct cldma_queue *queue, struct sk_buff *skb);
>   };

What was the purpose of moving the recv_skb callback between layers?

[skipped]

> diff --git a/drivers/net/wwan/t7xx/t7xx_pci.c b/drivers/net/wwan/t7xx/t7xx_pci.c
> index d5f6a8638aba..f51e5e2b41e1 100644
> --- a/drivers/net/wwan/t7xx/t7xx_pci.c
> +++ b/drivers/net/wwan/t7xx/t7xx_pci.c
> @@ -170,7 +170,8 @@ static int t7xx_pci_pm_init(struct t7xx_pci_dev *t7xx_dev)
>   	pm_runtime_set_autosuspend_delay(&pdev->dev, PM_AUTOSUSPEND_MS);
>   	pm_runtime_use_autosuspend(&pdev->dev);
>   
> -	return t7xx_wait_pm_config(t7xx_dev);
> +	t7xx_wait_pm_config(t7xx_dev);
> +	return 0;

What was the purpose of breaking the error reporting?

>   }
>   
>   void t7xx_pci_pm_init_late(struct t7xx_pci_dev *t7xx_dev)
> diff --git a/drivers/net/wwan/t7xx/t7xx_port.h b/drivers/net/wwan/t7xx/t7xx_port.h
> index 4ae8a00a8532..09acb1ef144d 100644
> --- a/drivers/net/wwan/t7xx/t7xx_port.h
> +++ b/drivers/net/wwan/t7xx/t7xx_port.h
> @@ -75,6 +75,8 @@ enum port_ch {
>   	PORT_CH_DSS6_TX = 0x20df,
>   	PORT_CH_DSS7_RX = 0x20e0,
>   	PORT_CH_DSS7_TX = 0x20e1,
> +
> +	PORT_CH_ID_UNIMPORTANT = 0xffff,

Do we need this '_ID_' inside the name?

>   };

[skipped]

> +static int t7xx_port_ctrl_start(struct wwan_port *port)

Please use consistent prefixes, when it is possible. Half of objects 
below have 't7xx_port_fastboot_' not 't7xx_port_ctrl_' prefix. And this 
is t7xx_port_fastboot.c file, what make more sence for the former prefix.

[skipped]

> +static const struct wwan_port_ops wwan_ops = {

Should it be called t7xx_port_fastboot_ops?

> +	.start = t7xx_port_ctrl_start,
> +	.stop = t7xx_port_ctrl_stop,
> +	.tx = t7xx_port_ctrl_tx,
> +};

[skipped]

> +struct port_ops fastboot_port_ops = {
> +	.init = t7xx_port_fastboot_init,
> +	.recv_skb = t7xx_port_fastboot_recv_skb,
> +	.uninit = t7xx_port_fastboot_uninit,
> +	.enable_chl = t7xx_port_fastboot_enable_chl,
> +	.disable_chl = t7xx_port_fastboot_disable_chl,
> +};
> diff --git a/drivers/net/wwan/t7xx/t7xx_port_proxy.c b/drivers/net/wwan/t7xx/t7xx_port_proxy.c
> index 274846d39fbf..0525a70acc81 100644
> --- a/drivers/net/wwan/t7xx/t7xx_port_proxy.c
> +++ b/drivers/net/wwan/t7xx/t7xx_port_proxy.c
> @@ -100,6 +100,21 @@ static const struct t7xx_port_conf t7xx_port_conf[] = {
>   	},
>   };
>   
> +static struct t7xx_port_conf t7xx_early_port_conf[] = {

Seems this array should be a constant.

> +	{
> +		.tx_ch = PORT_CH_ID_UNIMPORTANT,
> +		.rx_ch = PORT_CH_ID_UNIMPORTANT,
> +		.txq_index = CLDMA_Q_IDX_DUMP,
> +		.rxq_index = CLDMA_Q_IDX_DUMP,
> +		.txq_exp_index = CLDMA_Q_IDX_DUMP,
> +		.rxq_exp_index = CLDMA_Q_IDX_DUMP,
> +		.path_id = CLDMA_ID_AP,
> +		.ops = &fastboot_port_ops,
> +		.name = "FASTBOOT",

Is FASTBOOT abbriviation? Why is it spelled in capital?

> +		.port_type = WWAN_PORT_FASTBOOT,
> +	},
> +};

[skipped]

>   static int t7xx_proxy_alloc(struct t7xx_modem *md)
>   {
> +	unsigned int early_port_count = ARRAY_SIZE(t7xx_early_port_conf);
>   	unsigned int port_count = ARRAY_SIZE(t7xx_port_conf);
>   	struct device *dev = &md->t7xx_dev->pdev->dev;
>   	struct port_proxy *port_prox;
> -	int i;
>   
> +	port_count = max(port_count, early_port_count);
>   	port_prox = devm_kzalloc(dev, sizeof(*port_prox) + sizeof(struct t7xx_port) * port_count,
>   				 GFP_KERNEL);

If you need just a maximum size of two sets of ports, then it is 
possible to achieve this with a macro:

#define T7XX_MAX_POSSIBLE_PORTS_NUM \
      (max(ARRAY_SIZE(t7xx_port_conf), ARRAY_SIZE(t7xx_early_port_conf)))

devm_kzalloc(dev, sizeof(*port_prox) +
              sizeof(struct t7xx_port) * T7XX_MAX_POSSIBLE_PORTS_NUM,
              GFP_KERNEL);

[skipped]

>   #define T7XX_PCIE_MISC_DEV_STATUS		0x0d1c
> -#define MISC_STAGE_MASK				GENMASK(2, 0)
> -#define MISC_RESET_TYPE_PLDR			BIT(26)
>   #define MISC_RESET_TYPE_FLDR			BIT(27)
> -#define LINUX_STAGE				4
> +#define MISC_RESET_TYPE_PLDR			BIT(26)
> +#define MISC_LK_EVENT_MASK			GENMASK(11, 8)
> +#define HOST_EVENT_MASK				GENMASK(31, 28)
> +
> +enum lk_event_id {
> +	LK_EVENT_NORMAL = 0,
> +	LK_EVENT_CREATE_PD_PORT = 1,
> +	LK_EVENT_CREATE_POST_DL_PORT = 2,
> +	LK_EVENT_RESET = 7,
> +};
> +
> +#define MISC_STAGE_MASK				GENMASK(2, 0)

Why does MISC_STAGE_MASK seems to be recreated? Some whitespace changes 
or just a git-diff glitch?

> +enum t7xx_device_stage {
> +	T7XX_DEV_STAGE_INIT = 0,
> +	T7XX_DEV_STAGE_BROM_PRE = 1,
> +	T7XX_DEV_STAGE_BROM_POST = 2,
> +	T7XX_DEV_STAGE_LK = 3,
> +	T7XX_DEV_STAGE_LINUX = 4,
> +};

[skipped]

> -	ret = read_poll_timeout(ioread32, dev_status,
> -				(dev_status & MISC_STAGE_MASK) == LINUX_STAGE, 20000, 2000000,
> -				false, IREG_BASE(md->t7xx_dev) + T7XX_PCIE_MISC_DEV_STATUS);
> +	ret = read_poll_timeout(ioread32, status,
> +				((status & MISC_STAGE_MASK) == T7XX_DEV_STAGE_LINUX) ||
> +				((status & MISC_STAGE_MASK) == T7XX_DEV_STAGE_LK), 100000,
> +				20000000, false, IREG_BASE(md->t7xx_dev) +
> +				T7XX_PCIE_MISC_DEV_STATUS);

Can it be (re-)wrapped in a more readable way? Or can we use a macro 
here to make it readable again?

[skipped]

> diff --git a/drivers/net/wwan/t7xx/t7xx_state_monitor.h b/drivers/net/wwan/t7xx/t7xx_state_monitor.h
> index b0b3662ae6d7..9421bbd2f117 100644
> --- a/drivers/net/wwan/t7xx/t7xx_state_monitor.h
> +++ b/drivers/net/wwan/t7xx/t7xx_state_monitor.h
> @@ -96,6 +96,7 @@ struct t7xx_fsm_ctl {
>   	bool			exp_flg;
>   	spinlock_t		notifier_lock;		/* Protects notifier list */
>   	struct list_head	notifier_list;
> +	u32                     prev_status;

Why is it called 'previous status' do we store 'current status' in the 
same structure?

--
Sergey

Re: [net-next v3 2/3] net: wwan: t7xx: Add sysfs attribute for device state machine

[Sergey Ryazanov]

On 28.12.2023 11:44, Jinjian Song wrote:

[skipped]

> +	switch (mode) {
> +	case T7XX_READY:
> +		return sprintf(buf, "T7XX_MODEM_READY\n");
> +	case T7XX_RESET:
> +		return sprintf(buf, "T7XX_MODEM_RESET\n");
> +	case T7XX_FASTBOOT_DL_SWITCHING:
> +		return sprintf(buf, "T7XX_MODEM_FASTBOOT_DL_SWITCHING\n");
> +	case T7XX_FASTBOOT_DL_MODE:
> +		return sprintf(buf, "T7XX_MODEM_FASTBOOT_DL_MODE\n");
> +	case T7XX_FASTBOOT_DUMP_MODE:
> +		return sprintf(buf, "T7XX_MODEM_FASTBOOT_DUMP_MODE\n");
> +	default:
> +		return sprintf(buf, "T7XX_UNKNOWN\n");

Out of curiosity, what the purpose of this common prefix "T7XX_MODEM_"? 
Do you have a plan to support more then T7xx modems?

And BTW, can we use a lighter method of string copying like strncpy()?

--
Sergey

Re: [net-next v3 2/3] net: wwan: t7xx: Add sysfs attribute for device state machine

[Nelson, Shannon]

On 1/8/2024 1:37 PM, Sergey Ryazanov wrote:
> 
> On 28.12.2023 11:44, Jinjian Song wrote:
> 
> [skipped]
> 
>> +     switch (mode) {
>> +     case T7XX_READY:
>> +             return sprintf(buf, "T7XX_MODEM_READY\n");
>> +     case T7XX_RESET:
>> +             return sprintf(buf, "T7XX_MODEM_RESET\n");
>> +     case T7XX_FASTBOOT_DL_SWITCHING:
>> +             return sprintf(buf, "T7XX_MODEM_FASTBOOT_DL_SWITCHING\n");
>> +     case T7XX_FASTBOOT_DL_MODE:
>> +             return sprintf(buf, "T7XX_MODEM_FASTBOOT_DL_MODE\n");
>> +     case T7XX_FASTBOOT_DUMP_MODE:
>> +             return sprintf(buf, "T7XX_MODEM_FASTBOOT_DUMP_MODE\n");
>> +     default:
>> +             return sprintf(buf, "T7XX_UNKNOWN\n");
> 
> Out of curiosity, what the purpose of this common prefix "T7XX_MODEM_"?
> Do you have a plan to support more then T7xx modems?
> 
> And BTW, can we use a lighter method of string copying like strncpy()?

A quick note from the sidelines: better would be strscpy()
See 
https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings

sln


> 
> -- 
> Sergey
> 

Re: [net-next v3 2/3] net: wwan: t7xx: Add sysfs attribute for device state machine

[Jinjian Song]

>On 1/8/2024 1:37 PM, Sergey Ryazanov wrote:
>> 
>> On 28.12.2023 11:44, Jinjian Song wrote:
>> 
>> [skipped]
>> 
>>> +     switch (mode) {
>>> +     case T7XX_READY:
>>> +             return sprintf(buf, "T7XX_MODEM_READY\n");
>>> +     case T7XX_RESET:
>>> +             return sprintf(buf, "T7XX_MODEM_RESET\n");
>>> +     case T7XX_FASTBOOT_DL_SWITCHING:
>>> +             return sprintf(buf, 
>>> +"T7XX_MODEM_FASTBOOT_DL_SWITCHING\n");
>>> +     case T7XX_FASTBOOT_DL_MODE:
>>> +             return sprintf(buf, "T7XX_MODEM_FASTBOOT_DL_MODE\n");
>>> +     case T7XX_FASTBOOT_DUMP_MODE:
>>> +             return sprintf(buf, "T7XX_MODEM_FASTBOOT_DUMP_MODE\n");
>>> +     default:
>>> +             return sprintf(buf, "T7XX_UNKNOWN\n");
>> 
>> Out of curiosity, what the purpose of this common prefix "T7XX_MODEM_"?
>> Do you have a plan to support more then T7xx modems?
>> 
>> And BTW, can we use a lighter method of string copying like strncpy()?

>A quick note from the sidelines: better would be strscpy() See https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings

>sln

I will remove the common prefix "T7XX_MODEM_" which using only for T7XX modems.
Thanks, got it, let me do that using strscpy() instead of sprintf().

And BTW, should switch case structure be adjusted like follow:
static const char* modes[] = {
	[T7XX_READY] = "READY ",
	[T7XX_RESET] = "RESET",
	...
}

t7xx_mode_show() {
	...
	/*mode = T7XX_READY;*/
	return strscpy(buff, modes[mode], sizeof(modes[mode]));
}

Best Regards,
Jinjian
 

Re: [net-next v3 2/3] net: wwan: t7xx: Add sysfs attribute for device state machine

[Jinjian Song]

>On Thu, 28 Dec 2023 17:44:10 +0800 Jinjian Song wrote:
>> From: Jinjian Song <jinjian.song@fibocom.com>
>> 
>> Add support for userspace to get the device mode, e.g., 
>> reset/ready/fastboot mode.

>We need some info under Documentation/ describing the file / attr and how it's supposed to be used.

Yes, please let me add to the t7xx.rst document

>> diff --git a/drivers/net/wwan/t7xx/t7xx_modem_ops.c 
>> b/drivers/net/wwan/t7xx/t7xx_modem_ops.c
>> index 24e7d491468e..ae4578905a8d 100644
>> --- a/drivers/net/wwan/t7xx/t7xx_modem_ops.c
>> +++ b/drivers/net/wwan/t7xx/t7xx_modem_ops.c
>> @@ -192,6 +192,7 @@ static irqreturn_t t7xx_rgu_isr_thread(int irq, 
>> void *data)  {
>>  	struct t7xx_pci_dev *t7xx_dev = data;
>>  
>> +	atomic_set(&t7xx_dev->mode, T7XX_RESET);

>Why is ->mode atomic? There seem to be no RMW operations on it.
>You can use READ_ONCE() / WRITE_ONCE() on a normal integer.

Please let me modify as suggested.

>>  	msleep(RGU_RESET_DELAY_MS);
>>  	t7xx_reset_device_via_pmic(t7xx_dev);
>>  	return IRQ_HANDLED;
>> diff --git a/drivers/net/wwan/t7xx/t7xx_pci.c 
>> b/drivers/net/wwan/t7xx/t7xx_pci.c
>> index 91256e005b84..d5f6a8638aba 100644
>> --- a/drivers/net/wwan/t7xx/t7xx_pci.c
>> +++ b/drivers/net/wwan/t7xx/t7xx_pci.c
>> @@ -52,6 +52,68 @@
>>  #define PM_RESOURCE_POLL_TIMEOUT_US	10000
>>  #define PM_RESOURCE_POLL_STEP_US	100
>>  
>> +static ssize_t t7xx_mode_store(struct device *dev,
>> +			       struct device_attribute *attr,
>> +			       const char *buf, size_t count) {
>> +	struct pci_dev *pdev;
>> +	struct t7xx_pci_dev *t7xx_dev;
>> +
>> +	pdev = to_pci_dev(dev);
>> +	t7xx_dev = pci_get_drvdata(pdev);
>> +	if (!t7xx_dev)
>> +		return -ENODEV;
>> +
>> +	atomic_set(&t7xx_dev->mode, T7XX_FASTBOOT_DL_SWITCHING);

>This function doesn't use @buf at all. So whenever user does write() to the file we set to SWITCHING? Shouldn't we narrow down the set of accepted values to be able to add more functionality later?

Yes, it doesn't use buff, just now only allows user setting SWITCHING.
Please let me narrow down the set to be more functionality.

>> +	return count;
>> +};

>unnecessary semi-colon

Best Regards,
Jinjian