net: wwan: t7xx: Add AP CLDMA

At this moment with the current status, t7xx is not functional due to
problems like this after connection, if there is no activity:
[ 57.370534] mtk_t7xx 0000:72:00.0: [PM] SAP suspend error: -110
[ 57.370581] mtk_t7xx 0000:72:00.0: can't suspend
(t7xx_pci_pm_runtime_suspend [mtk_t7xx] returned -110)
because after this, the traffic no longer works.

The complete series 'net: wwan: t7xx: fw flashing & coredump support'
was reverted because of issues with the pci implementation.
In order to have at least the modem working, it would be enough if just
the first commit of the series is re-applied:
d20ef656f994 net: wwan: t7xx: Add AP CLDMA
With that, the Application Processor would be controlled, correctly
suspended and the commented problems would be fixed (I am testing here
like this with no related issue).

This commit is independent of the others and not related to the
commented pci implementation for the new features: fw flashing and
coredump collection.

Use v2 patch version of d20ef656f994 as JinJian Song suggests
(https://patchwork.kernel.org/project/netdevbpf/patch/[e-mail]/).

Original text from the commit that would be re-applied:

d20ef656f994 net: wwan: t7xx: Add AP CLDMA
Author: Haijun Liu <[e-mail]>
Date: Tue Aug 16 09:53:28 2022 +0530

The t7xx device contains two Cross Layer DMA (CLDMA) interfaces to
communicate with AP and Modem processors respectively. So far only
MD-CLDMA was being used, this patch enables AP-CLDMA.

Rename small Application Processor (sAP) to AP.

Signed-off-by: Haijun Liu <[e-mail]>
Co-developed-by: Madhusmita Sahu <[e-mail]>
Signed-off-by: Madhusmita Sahu <[e-mail]>
Signed-off-by: Moises Veleta <[e-mail]>
Signed-off-by: Devegowda Chandrashekar <[e-mail]>
Signed-off-by: M Chetan Kumar <[e-mail]>
Reviewed-by: Ilpo Järvinen <[e-mail]>
Reviewed-by: Sergey Ryazanov <[e-mail]>
Reviewed-by: Jesse Brandeburg <[e-mail]>

Signed-off-by: Jose Ignacio Tornos Martinez <[e-mail]>
Reviewed-by: Simon Horman <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/wwan/t7xx/t7xx_hif_cldma.c

···
 	struct t7xx_cldma_hw *hw_info = &md_ctrl->hw_info;
 	u32 phy_ao_base, phy_pd_base;
 
-	if (md_ctrl->hif_id != CLDMA_ID_MD)
-		return;
-
-	phy_ao_base = CLDMA1_AO_BASE;
-	phy_pd_base = CLDMA1_PD_BASE;
-	hw_info->phy_interrupt_id = CLDMA1_INT;
 	hw_info->hw_mode = MODE_BIT_64;
+
+	if (md_ctrl->hif_id == CLDMA_ID_MD) {
+		phy_ao_base = CLDMA1_AO_BASE;
+		phy_pd_base = CLDMA1_PD_BASE;
+		hw_info->phy_interrupt_id = CLDMA1_INT;
+	} else {
+		phy_ao_base = CLDMA0_AO_BASE;
+		phy_pd_base = CLDMA0_PD_BASE;
+		hw_info->phy_interrupt_id = CLDMA0_INT;
+	}
+
 	hw_info->ap_ao_base = t7xx_pcie_addr_transfer(pbase->pcie_ext_reg_base,
 						      pbase->pcie_dev_reg_trsl_addr, phy_ao_base);
 	hw_info->ap_pdn_base = t7xx_pcie_addr_transfer(pbase->pcie_ext_reg_base,

drivers/net/wwan/t7xx/t7xx_hif_cldma.h

···
 /**
  * enum cldma_id - Identifiers for CLDMA HW units.
  * @CLDMA_ID_MD: Modem control channel.
- * @CLDMA_ID_AP: Application Processor control channel (not used at the moment).
+ * @CLDMA_ID_AP: Application Processor control channel.
  * @CLDMA_NUM:   Number of CLDMA HW units available.
  */
 enum cldma_id {

drivers/net/wwan/t7xx/t7xx_mhccif.h

···
 			 D2H_INT_EXCEPTION_CLEARQ_DONE |	\
 			 D2H_INT_EXCEPTION_ALLQ_RESET |		\
 			 D2H_INT_PORT_ENUM |			\
+			 D2H_INT_ASYNC_AP_HK |			\
 			 D2H_INT_ASYNC_MD_HK)
 
 void t7xx_mhccif_mask_set(struct t7xx_pci_dev *t7xx_dev, u32 val);

drivers/net/wwan/t7xx/t7xx_modem_ops.c

···
 #include "t7xx_state_monitor.h"
 
 #define RT_ID_MD_PORT_ENUM	0
+#define RT_ID_AP_PORT_ENUM	1
 /* Modem feature query identification code - "ICCC" */
 #define MD_FEATURE_QUERY_ID	0x49434343
 
···
 	}
 
 	t7xx_cldma_exception(md->md_ctrl[CLDMA_ID_MD], stage);
+	t7xx_cldma_exception(md->md_ctrl[CLDMA_ID_AP], stage);
 
 	if (stage == HIF_EX_INIT)
 		t7xx_mhccif_h2d_swint_trigger(t7xx_dev, H2D_CH_EXCEPTION_ACK);
···
 		if (ft_spt_st != MTK_FEATURE_MUST_BE_SUPPORTED)
 			return -EINVAL;
 
-		if (i == RT_ID_MD_PORT_ENUM)
+		if (i == RT_ID_MD_PORT_ENUM || i == RT_ID_AP_PORT_ENUM)
 			t7xx_port_enum_msg_handler(ctl->md, rt_feature->data);
 	}
 
···
 	return 0;
 }
 
-static void t7xx_core_hk_handler(struct t7xx_modem *md, struct t7xx_fsm_ctl *ctl,
+static void t7xx_core_hk_handler(struct t7xx_modem *md, struct t7xx_sys_info *core_info,
+				 struct t7xx_fsm_ctl *ctl,
 				 enum t7xx_fsm_event_state event_id,
 				 enum t7xx_fsm_event_state err_detect)
 {
 	struct t7xx_fsm_event *event = NULL, *event_next;
-	struct t7xx_sys_info *core_info = &md->core_md;
 	struct device *dev = &md->t7xx_dev->pdev->dev;
 	unsigned long flags;
 	int ret;
···
 	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;
-	t7xx_core_hk_handler(md, ctl, FSM_EVENT_MD_HS2, FSM_EVENT_MD_HS2_EXIT);
+	t7xx_core_hk_handler(md, &md->core_md, ctl, FSM_EVENT_MD_HS2, FSM_EVENT_MD_HS2_EXIT);
+}
+
+static void t7xx_ap_hk_wq(struct work_struct *work)
+{
+	struct t7xx_modem *md = container_of(work, struct t7xx_modem, ap_handshake_work);
+	struct t7xx_fsm_ctl *ctl = md->fsm_ctl;
+
+	 /* 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_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);
 }
 
 void t7xx_md_event_notify(struct t7xx_modem *md, enum md_event_id evt_id)
 {
 	struct t7xx_fsm_ctl *ctl = md->fsm_ctl;
-	void __iomem *mhccif_base;
 	unsigned int int_sta;
 	unsigned long flags;
 
 	switch (evt_id) {
 	case FSM_PRE_START:
-		t7xx_mhccif_mask_clr(md->t7xx_dev, D2H_INT_PORT_ENUM);
+		t7xx_mhccif_mask_clr(md->t7xx_dev, D2H_INT_PORT_ENUM | D2H_INT_ASYNC_MD_HK |
+						   D2H_INT_ASYNC_AP_HK);
 		break;
 
 	case FSM_START:
···
 			ctl->exp_flg = true;
 			md->exp_id &= ~D2H_INT_EXCEPTION_INIT;
 			md->exp_id &= ~D2H_INT_ASYNC_MD_HK;
+			md->exp_id &= ~D2H_INT_ASYNC_AP_HK;
 		} else if (ctl->exp_flg) {
 			md->exp_id &= ~D2H_INT_ASYNC_MD_HK;
-		} else if (md->exp_id & D2H_INT_ASYNC_MD_HK) {
-			queue_work(md->handshake_wq, &md->handshake_work);
-			md->exp_id &= ~D2H_INT_ASYNC_MD_HK;
-			mhccif_base = md->t7xx_dev->base_addr.mhccif_rc_base;
-			iowrite32(D2H_INT_ASYNC_MD_HK, mhccif_base + REG_EP2RC_SW_INT_ACK);
-			t7xx_mhccif_mask_set(md->t7xx_dev, D2H_INT_ASYNC_MD_HK);
+			md->exp_id &= ~D2H_INT_ASYNC_AP_HK;
 		} else {
-			t7xx_mhccif_mask_clr(md->t7xx_dev, D2H_INT_ASYNC_MD_HK);
+			void __iomem *mhccif_base = md->t7xx_dev->base_addr.mhccif_rc_base;
+
+			if (md->exp_id & D2H_INT_ASYNC_MD_HK) {
+				queue_work(md->handshake_wq, &md->handshake_work);
+				md->exp_id &= ~D2H_INT_ASYNC_MD_HK;
+				iowrite32(D2H_INT_ASYNC_MD_HK, mhccif_base + REG_EP2RC_SW_INT_ACK);
+				t7xx_mhccif_mask_set(md->t7xx_dev, D2H_INT_ASYNC_MD_HK);
+			}
+
+			if (md->exp_id & D2H_INT_ASYNC_AP_HK) {
+				queue_work(md->handshake_wq, &md->ap_handshake_work);
+				md->exp_id &= ~D2H_INT_ASYNC_AP_HK;
+				iowrite32(D2H_INT_ASYNC_AP_HK, mhccif_base + REG_EP2RC_SW_INT_ACK);
+				t7xx_mhccif_mask_set(md->t7xx_dev, D2H_INT_ASYNC_AP_HK);
+			}
 		}
 		spin_unlock_irqrestore(&md->exp_lock, flags);
 
···
 
 	case FSM_READY:
 		t7xx_mhccif_mask_set(md->t7xx_dev, D2H_INT_ASYNC_MD_HK);
+		t7xx_mhccif_mask_set(md->t7xx_dev, D2H_INT_ASYNC_AP_HK);
 		break;
 
 	default:
···
 	md->core_md.feature_set[RT_ID_MD_PORT_ENUM] &= ~FEATURE_MSK;
 	md->core_md.feature_set[RT_ID_MD_PORT_ENUM] |=
 		FIELD_PREP(FEATURE_MSK, MTK_FEATURE_MUST_BE_SUPPORTED);
+
+	INIT_WORK(&md->ap_handshake_work, t7xx_ap_hk_wq);
+	md->core_ap.feature_set[RT_ID_AP_PORT_ENUM] &= ~FEATURE_MSK;
+	md->core_ap.feature_set[RT_ID_AP_PORT_ENUM] |=
+		FIELD_PREP(FEATURE_MSK, MTK_FEATURE_MUST_BE_SUPPORTED);
+
 	return md;
 }
 
···
 	md->exp_id = 0;
 	t7xx_fsm_reset(md);
 	t7xx_cldma_reset(md->md_ctrl[CLDMA_ID_MD]);
+	t7xx_cldma_reset(md->md_ctrl[CLDMA_ID_AP]);
 	t7xx_port_proxy_reset(md->port_prox);
 	md->md_init_finish = true;
 	return t7xx_core_reset(md);
···
 	if (ret)
 		goto err_destroy_hswq;
 
+	ret = t7xx_cldma_alloc(CLDMA_ID_AP, t7xx_dev);
+	if (ret)
+		goto err_destroy_hswq;
+
 	ret = t7xx_fsm_init(md);
 	if (ret)
 		goto err_destroy_hswq;
···
 	if (ret)
 		goto err_uninit_ccmni;
 
-	ret = t7xx_port_proxy_init(md);
+	ret = t7xx_cldma_init(md->md_ctrl[CLDMA_ID_AP]);
 	if (ret)
 		goto err_uninit_md_cldma;
 
+	ret = t7xx_port_proxy_init(md);
+	if (ret)
+		goto err_uninit_ap_cldma;
+
 	ret = t7xx_fsm_append_cmd(md->fsm_ctl, FSM_CMD_START, 0);
-	if (ret) /* fsm_uninit flushes cmd queue */
+	if (ret) /* t7xx_fsm_uninit() flushes cmd queue */
 		goto err_uninit_proxy;
 
 	t7xx_md_sys_sw_init(t7xx_dev);
···
 
 err_uninit_proxy:
 	t7xx_port_proxy_uninit(md->port_prox);
+
+err_uninit_ap_cldma:
+	t7xx_cldma_exit(md->md_ctrl[CLDMA_ID_AP]);
 
 err_uninit_md_cldma:
 	t7xx_cldma_exit(md->md_ctrl[CLDMA_ID_MD]);
···
 
 	t7xx_fsm_append_cmd(md->fsm_ctl, FSM_CMD_PRE_STOP, FSM_CMD_FLAG_WAIT_FOR_COMPLETION);
 	t7xx_port_proxy_uninit(md->port_prox);
+	t7xx_cldma_exit(md->md_ctrl[CLDMA_ID_AP]);
 	t7xx_cldma_exit(md->md_ctrl[CLDMA_ID_MD]);
 	t7xx_ccmni_exit(t7xx_dev);
 	t7xx_fsm_uninit(md);

drivers/net/wwan/t7xx/t7xx_modem_ops.h

···
 	struct cldma_ctrl		*md_ctrl[CLDMA_NUM];
 	struct t7xx_pci_dev		*t7xx_dev;
 	struct t7xx_sys_info		core_md;
+	struct t7xx_sys_info		core_ap;
 	bool				md_init_finish;
 	bool				rgu_irq_asserted;
 	struct workqueue_struct		*handshake_wq;
 	struct work_struct		handshake_work;
+	struct work_struct		ap_handshake_work;
 	struct t7xx_fsm_ctl		*fsm_ctl;
 	struct port_proxy		*port_prox;
 	unsigned int			exp_id;

drivers/net/wwan/t7xx/t7xx_port.h

···
 /* Channel ID and Message ID definitions.
  * The channel number consists of peer_id(15:12) , channel_id(11:0)
  * peer_id:
- * 0:reserved, 1: to sAP, 2: to MD
+ * 0:reserved, 1: to AP, 2: to MD
  */
 enum port_ch {
+	/* to AP */
+	PORT_CH_AP_CONTROL_RX = 0x1000,
+	PORT_CH_AP_CONTROL_TX = 0x1001,
+
 	/* to MD */
 	PORT_CH_CONTROL_RX = 0x2000,
 	PORT_CH_CONTROL_TX = 0x2001,

drivers/net/wwan/t7xx/t7xx_port_ctrl_msg.c

···
 	case CTL_ID_HS2_MSG:
 		skb_pull(skb, sizeof(*ctrl_msg_h));
 
-		if (port_conf->rx_ch == PORT_CH_CONTROL_RX) {
-			ret = t7xx_fsm_append_event(ctl, FSM_EVENT_MD_HS2, skb->data,
+		if (port_conf->rx_ch == PORT_CH_CONTROL_RX ||
+		    port_conf->rx_ch == PORT_CH_AP_CONTROL_RX) {
+			int event = port_conf->rx_ch == PORT_CH_CONTROL_RX ?
+				    FSM_EVENT_MD_HS2 : FSM_EVENT_AP_HS2;
+
+			ret = t7xx_fsm_append_event(ctl, event, skb->data,
 						    le32_to_cpu(ctrl_msg_h->data_length));
 			if (ret)
 				dev_err(port->dev, "Failed to append Handshake 2 event");

drivers/net/wwan/t7xx/t7xx_port_proxy.c

···
 	     i < (proxy)->port_count;		\
 	     i++, (p) = &(proxy)->ports[i])
 
-static const struct t7xx_port_conf t7xx_md_port_conf[] = {
+static const struct t7xx_port_conf t7xx_port_conf[] = {
 	{
 		.tx_ch = PORT_CH_UART2_TX,
 		.rx_ch = PORT_CH_UART2_RX,
···
 		.path_id = CLDMA_ID_MD,
 		.ops = &ctl_port_ops,
 		.name = "t7xx_ctrl",
+	}, {
+		.tx_ch = PORT_CH_AP_CONTROL_TX,
+		.rx_ch = PORT_CH_AP_CONTROL_RX,
+		.txq_index = Q_IDX_CTRL,
+		.rxq_index = Q_IDX_CTRL,
+		.path_id = CLDMA_ID_AP,
+		.ops = &ctl_port_ops,
+		.name = "t7xx_ap_ctrl",
 	},
 };
 
···
 		if (port_conf->tx_ch == PORT_CH_CONTROL_TX)
 			md->core_md.ctl_port = port;
 
+		if (port_conf->tx_ch == PORT_CH_AP_CONTROL_TX)
+			md->core_ap.ctl_port = port;
+
 		port->t7xx_dev = md->t7xx_dev;
 		port->dev = &md->t7xx_dev->pdev->dev;
 		spin_lock_init(&port->port_update_lock);
···
 
 static int t7xx_proxy_alloc(struct t7xx_modem *md)
 {
-	unsigned int port_count = ARRAY_SIZE(t7xx_md_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_prox->dev = dev;
 
 	for (i = 0; i < port_count; i++)
-		port_prox->ports[i].port_conf = &t7xx_md_port_conf[i];
+		port_prox->ports[i].port_conf = &t7xx_port_conf[i];
 
 	port_prox->port_count = port_count;
 	t7xx_proxy_init_all_ports(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;
 }

drivers/net/wwan/t7xx/t7xx_reg.h

···
 #define D2H_INT_RESUME_ACK			BIT(12)
 #define D2H_INT_SUSPEND_ACK_AP			BIT(13)
 #define D2H_INT_RESUME_ACK_AP			BIT(14)
-#define D2H_INT_ASYNC_SAP_HK			BIT(15)
+#define D2H_INT_ASYNC_AP_HK			BIT(15)
 #define D2H_INT_ASYNC_MD_HK			BIT(16)
 
 /* Register base */

drivers/net/wwan/t7xx/t7xx_state_monitor.c

···
 	t7xx_fsm_broadcast_state(ctl, MD_STATE_WAITING_FOR_HS1);
 	t7xx_md_event_notify(md, FSM_START);
 
-	wait_event_interruptible_timeout(ctl->async_hk_wq, md->core_md.ready || ctl->exp_flg,
-					 HZ * 60);
+	wait_event_interruptible_timeout(ctl->async_hk_wq,
+					 (md->core_md.ready && md->core_ap.ready) ||
+					  ctl->exp_flg, HZ * 60);
 	dev = &md->t7xx_dev->pdev->dev;
 
 	if (ctl->exp_flg)
···
 		dev_err(dev, "MD handshake timeout\n");
 		if (md->core_md.handshake_ongoing)
 			t7xx_fsm_append_event(ctl, FSM_EVENT_MD_HS2_EXIT, NULL, 0);
+
+		fsm_routine_exception(ctl, NULL, EXCEPTION_HS_TIMEOUT);
+		return -ETIMEDOUT;
+	} else if (!md->core_ap.ready) {
+		dev_err(dev, "AP handshake timeout\n");
+		if (md->core_ap.handshake_ongoing)
+			t7xx_fsm_append_event(ctl, FSM_EVENT_AP_HS2_EXIT, NULL, 0);
 
 		fsm_routine_exception(ctl, NULL, EXCEPTION_HS_TIMEOUT);
 		return -ETIMEDOUT;
···
 		return;
 	}
 
+	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));
 }

drivers/net/wwan/t7xx/t7xx_state_monitor.h

···
 enum t7xx_fsm_event_state {
 	FSM_EVENT_INVALID,
 	FSM_EVENT_MD_HS2,
+	FSM_EVENT_AP_HS2,
 	FSM_EVENT_MD_EX,
 	FSM_EVENT_MD_EX_REC_OK,
 	FSM_EVENT_MD_EX_PASS,
 	FSM_EVENT_MD_HS2_EXIT,
+	FSM_EVENT_AP_HS2_EXIT,
 	FSM_EVENT_MAX
 };