[PATCH v3 10/13] wifi: mt76: mt7925: add MT7927 hardware initialization

[Javier Tia <floss@jetm.me>]

Add MT7927-specific hardware initialization for the Filogic 380 combo
chip, which has an additional CBInfra (ConnectaBus Infrastructure) bus
fabric between PCIe and the WiFi subsystem.

CBTOP remap: configure PCIe address mapping so MMIO reads to WiFi
registers return valid data instead of zero.

Chip initialization sequence:
  1. WF subsystem reset via CBInfra RGU
  2. MCU ownership acquisition
  3. Poll ROMCODE_INDEX for MCU idle (0x1D1E)
  4. MCIF remap for host DMA
  5. PCIe sleep disable

Probe flow changes for MT7927:
  - Skip early CLR_OWN (CBTOP not yet configured)
  - Force chip ID if CHIPID register returns stale value
  - Replace wfsys_reset with mt7927_chip_init

CLR_OWN skip in mt7925e_mcu_init(): every CLR_OWN triggers the ROM to
reinitialize WFDMA, destroying ring configuration set up by DMA init.
The controlled SET_OWN/CLR_OWN is already handled in the DMA pre-ring
setup hook.

DBDC enable: MT7927 firmware defaults to single-band (2.4GHz only).
Send explicit SET_DBDC_PARMS to enable dual-band operation.

CNM force: MT7927 firmware lacks the connac2 feature trailer, causing
channel context ops to be replaced with stubs. Force the CNM flag at
probe to preserve ROC support needed for authentication.

mac_reset guard: return -EOPNOTSUPP for MT7927 since the reset path
performs CLR_OWN and logic reset that destroy DMA configuration. Full
reset recovery is follow-up work.

Register values derived from Loong0x00's reverse-engineered MT7927
driver.

Reported-by: 张旭涵 <Loong.0x00@gmail.com>
Closes: https://github.com/openwrt/mt76/issues/927
Tested-by: Marcin FM <marcin@lgic.pl>
Tested-by: Cristian-Florin Radoi <radoi.chris@gmail.com>
Tested-by: George Salukvadze <giosal90@gmail.com>
Tested-by: Evgeny Kapusta <3193631@gmail.com>
Tested-by: Samu Toljamo <samu.toljamo@gmail.com>
Tested-by: Ariel Rosenfeld <ariel.rosenfeld.750@gmail.com>
Tested-by: Chapuis Dario <chapuisdario4@gmail.com>
Tested-by: Thibaut François <tibo@humeurlibre.fr>
Tested-by: 张旭涵 <Loong.0x00@gmail.com>
Signed-off-by: Javier Tia <floss@jetm.me>
---
 drivers/net/wireless/mediatek/mt76/mt7925/init.c   |  13 +++
 drivers/net/wireless/mediatek/mt76/mt7925/pci.c    | 103 +++++++++++++++++++--
 .../net/wireless/mediatek/mt76/mt7925/pci_mac.c    |   9 ++
 .../net/wireless/mediatek/mt76/mt7925/pci_mcu.c    |  20 ++--
 drivers/net/wireless/mediatek/mt76/mt792x_regs.h   |  18 ++++
 5 files changed, 149 insertions(+), 14 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/init.c b/drivers/net/wireless/mediatek/mt76/mt7925/init.c
index 3ce5d6fcc69d..c4c99380f5b5 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7925/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7925/init.c
@@ -115,6 +115,19 @@ static int __mt7925_init_hardware(struct mt792x_dev *dev)
 	if (ret)
 		goto out;
 
+	/* MT7927: Enable DBDC (dual-band) mode. Without this, firmware
+	 * defaults to 2.4GHz only and ignores 5GHz scan requests.
+	 * MT7925 firmware handles DBDC automatically.
+	 */
+	if (is_mt7927(&dev->mt76)) {
+		ret = mt7925_mcu_set_dbdc(&dev->mphy, true);
+		if (ret) {
+			dev_warn(dev->mt76.dev,
+				 "MT7927 DBDC enable failed: %d\n", ret);
+			ret = 0;
+		}
+	}
+
 out:
 	return ret;
 }
diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/pci.c b/drivers/net/wireless/mediatek/mt76/mt7925/pci.c
index 415194a440f8..393d9f408b84 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7925/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7925/pci.c
@@ -400,6 +400,64 @@ static const struct mt792x_irq_map mt7927_irq_map = {
 		.wm2_complete_mask = MT7927_RX_DONE_INT_ENA7,
 	},
 };
+
+static int mt7927_chip_init(struct mt792x_dev *dev)
+{
+	struct mt76_dev *mdev = &dev->mt76;
+	u32 val;
+
+	/* EMI sleep protect */
+	mt76_rmw_field(dev, MT_HW_EMI_CTL, MT_HW_EMI_CTL_SLPPROT_EN, 1);
+
+	/* WF subsystem reset via CBInfra RGU */
+	mt76_set(dev, MT7927_CBINFRA_RGU_WF_RST,
+		 MT7927_CBINFRA_RGU_WF_RST_WF_SUBSYS);
+	msleep(1);
+	mt76_clear(dev, MT7927_CBINFRA_RGU_WF_RST,
+		   MT7927_CBINFRA_RGU_WF_RST_WF_SUBSYS);
+	msleep(5);
+
+	/* MCU ownership */
+	mt76_wr(dev, MT7927_CBINFRA_MCU_OWN_SET, BIT(0));
+
+	/* Poll ROMCODE_INDEX for MCU idle */
+	if (!__mt76_poll_msec(mdev, MT7927_ROMCODE_INDEX,
+			      0xffff, MT7927_MCU_IDLE_VALUE, 2000)) {
+		val = mt76_rr(dev, MT7927_ROMCODE_INDEX);
+		dev_err(mdev->dev,
+			"MT7927 MCU idle timeout (ROMCODE_INDEX=0x%04x)\n",
+			val & 0xffff);
+		return -ETIMEDOUT;
+	}
+
+	/* MCIF remap - MCU needs this to DMA to host memory */
+	mt76_wr(dev, MT7927_MCIF_REMAP_WF_1_BA,
+		MT7927_MCIF_REMAP_WF_1_BA_VAL);
+
+	/* Disable PCIe sleep */
+	mt76_wr(dev, MT7927_CBINFRA_SLP_CTRL, 0xffffffff);
+
+	/* Clear CONNINFRA wakeup */
+	mt76_wr(dev, MT7927_CBINFRA_WAKEPU_TOP, 0x0);
+
+	return 0;
+}
+
+static void mt7927_cbtop_remap(struct mt792x_dev *dev)
+{
+	/* CONNINFRA wakeup - required before CBInfra register access */
+	mt76_wr(dev, MT7927_CBINFRA_WAKEPU_TOP, 0x1);
+	usleep_range(1000, 2000);
+
+	/* Configure CBTOP PCIe address remap for WF and BT */
+	mt76_wr(dev, MT7927_CBINFRA_MISC0_REMAP_WF,
+		MT7927_CBINFRA_REMAP_WF_VAL);
+	mt76_wr(dev, MT7927_CBINFRA_MISC0_REMAP_BT,
+		MT7927_CBINFRA_REMAP_BT_VAL);
+
+	/* Readback to push writes */
+	mt76_rr(dev, MT7927_CBINFRA_MISC0_REMAP_WF);
+}
 static int mt7925_pci_probe(struct pci_dev *pdev,
 			    const struct pci_device_id *id)
 {
@@ -482,6 +540,17 @@ static int mt7925_pci_probe(struct pci_dev *pdev,
 		goto err_free_pci_vec;
 	}
 
+	/* MT7927 firmware lacks the connac2 feature trailer, so
+	 * mt792x_get_mac80211_ops() can't detect CNM support and
+	 * replaces chanctx/ROC/mgd_prepare_tx ops with stubs.
+	 * Force CNM and restore the original mt7925 ops.
+	 */
+	if ((pdev->device == 0x6639 || pdev->device == 0x7927) &&
+	    !(features & MT792x_FW_CAP_CNM)) {
+		features |= MT792x_FW_CAP_CNM;
+		memcpy(ops, &mt7925_ops, sizeof(*ops));
+	}
+
 	mdev = mt76_alloc_device(&pdev->dev, sizeof(*dev), ops, &drv_ops);
 	if (!mdev) {
 		ret = -ENOMEM;
@@ -517,25 +586,43 @@ static int mt7925_pci_probe(struct pci_dev *pdev,
 
 	if (!mt7925_disable_aspm && mt76_pci_aspm_supported(pdev))
 		dev->aspm_supported = true;
-
 	ret = __mt792x_mcu_fw_pmctrl(dev);
 	if (ret)
 		goto err_free_dev;
 
-	ret = __mt792xe_mcu_drv_pmctrl(dev);
-	if (ret)
-		goto err_free_dev;
+	if (!is_mt7927_hw) {
+		ret = __mt792xe_mcu_drv_pmctrl(dev);
+		if (ret)
+			goto err_free_dev;
+	}
+
+	if (is_mt7927_hw)
+		mt7927_cbtop_remap(dev);
 
 	mdev->rev = (mt76_rr(dev, MT_HW_CHIPID) << 16) |
 		    (mt76_rr(dev, MT_HW_REV) & 0xff);
 
 	dev_info(mdev->dev, "ASIC revision: %04x\n", mdev->rev);
 
-	mt76_rmw_field(dev, MT_HW_EMI_CTL, MT_HW_EMI_CTL_SLPPROT_EN, 1);
+	/* Force chip ID for MT7927 hardware if CHIPID read returns garbage */
+	if (is_mt7927_hw && (mdev->rev >> 16) != 0x7927) {
+		dev_info(mdev->dev,
+			 "MT7927 raw CHIPID=0x%04x, forcing chip=0x7927\n",
+			 (u16)(mdev->rev >> 16));
+		mdev->rev = (0x7927 << 16) | (mdev->rev & 0xff);
+	}
 
-	ret = mt792x_wfsys_reset(dev);
-	if (ret)
-		goto err_free_dev;
+	if (is_mt7927_hw) {
+		ret = mt7927_chip_init(dev);
+		if (ret)
+			goto err_free_dev;
+	} else {
+		mt76_rmw_field(dev, MT_HW_EMI_CTL,
+			       MT_HW_EMI_CTL_SLPPROT_EN, 1);
+		ret = mt792x_wfsys_reset(dev);
+		if (ret)
+			goto err_free_dev;
+	}
 
 	mt76_wr(dev, irq_map.host_irq_enable, 0);
 
diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/pci_mac.c b/drivers/net/wireless/mediatek/mt76/mt7925/pci_mac.c
index 1626a3684082..9b3eeb1328f6 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7925/pci_mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7925/pci_mac.c
@@ -72,6 +72,15 @@ int mt7925e_mac_reset(struct mt792x_dev *dev)
 	const struct mt792x_irq_map *irq_map = dev->irq_map;
 	int i, err;
 
+	/* MT7927: CLR_OWN and WPDMA reset destroy DMA ring configuration.
+	 * A full reset requires re-running mt7927_dma_init() which is not
+	 * yet implemented in the recovery path.
+	 */
+	if (is_mt7927(&dev->mt76)) {
+		dev_warn(dev->mt76.dev, "MT7927 mac_reset not supported, reload module to recover\n");
+		return -EOPNOTSUPP;
+	}
+
 	mt792xe_mcu_drv_pmctrl(dev);
 
 	mt76_connac_free_pending_tx_skbs(&dev->pm, NULL);
diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/pci_mcu.c b/drivers/net/wireless/mediatek/mt76/mt7925/pci_mcu.c
index 6cceff88c656..1f50d1ef6fb6 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7925/pci_mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7925/pci_mcu.c
@@ -35,13 +35,21 @@ int mt7925e_mcu_init(struct mt792x_dev *dev)
 
 	dev->mt76.mcu_ops = &mt7925_mcu_ops;
 
-	err = mt792xe_mcu_fw_pmctrl(dev);
-	if (err)
-		return err;
+	if (is_mt7927(&dev->mt76)) {
+		/* MT7927: CLR_OWN was already done in mt7927_dma_init().
+		 * The ROM re-initializes WFDMA on every CLR_OWN, wiping
+		 * ring and prefetch config. Skip SET_OWN/CLR_OWN here
+		 * to preserve DMA state.
+		 */
+	} else {
+		err = mt792xe_mcu_fw_pmctrl(dev);
+		if (err)
+			return err;
 
-	err = __mt792xe_mcu_drv_pmctrl(dev);
-	if (err)
-		return err;
+		err = __mt792xe_mcu_drv_pmctrl(dev);
+		if (err)
+			return err;
+	}
 
 	mt76_rmw_field(dev, MT_PCIE_MAC_PM, MT_PCIE_MAC_PM_L0S_DIS, 1);
 
diff --git a/drivers/net/wireless/mediatek/mt76/mt792x_regs.h b/drivers/net/wireless/mediatek/mt76/mt792x_regs.h
index 1b9b51d43f79..9c4bbbe898f3 100644
--- a/drivers/net/wireless/mediatek/mt76/mt792x_regs.h
+++ b/drivers/net/wireless/mediatek/mt76/mt792x_regs.h
@@ -499,4 +499,22 @@
 #define WFSYS_SW_RST_B			BIT(0)
 #define WFSYS_SW_INIT_DONE		BIT(4)
 
+/* CBInfra registers - MT7927 combo chip */
+#define MT7927_CBINFRA_WAKEPU_TOP		0xe01a0
+#define MT7927_CBINFRA_MISC0_REMAP_WF		0x1f6554
+#define MT7927_CBINFRA_MISC0_REMAP_BT		0x1f6558
+#define MT7927_CBINFRA_RGU_WF_RST		0x1f8600
+#define MT7927_CBINFRA_RGU_WF_RST_WF_SUBSYS	BIT(4)
+#define MT7927_CBINFRA_MCU_OWN_SET		0x1f5034
+#define MT7927_CBINFRA_SLP_CTRL			0x1f5018
+#define MT7927_ROMCODE_INDEX			0xc1604
+#define MT7927_MCU_IDLE_VALUE			0x1d1e
+#define MT7927_MCIF_REMAP_WF_1_BA		0xd1034
+
+/* CBInfra CBTOP remap values */
+#define MT7927_CBINFRA_REMAP_WF_VAL		0x74037001
+#define MT7927_CBINFRA_REMAP_BT_VAL		0x70007000
+
+#define MT7927_MCIF_REMAP_WF_1_BA_VAL		0x18051803
+
 #endif /* __MT792X_REGS_H */

-- 
2.53.0