[PATCH v3 07/11] PCI: rockchip: Fix legacy IRQ generation for RK3399 PCIe endpoint core

[Rick Wertenbroek <rick.wertenbroek@gmail.com>]

Fix legacy IRQ generation for RK3399 PCIe endpoint core according to
the technical reference manual (TRM). Assert and deassert legacy
interrupt (INTx) through the legacy interrupt control register
("PCIE_CLIENT_LEGACY_INT_CTRL") instead of manually generating a PCIe
message. The generation of the legacy interrupt was tested and validated
with the PCIe endpoint test driver.

Fixes: cf590b078391 ("PCI: rockchip: Add EP driver for Rockchip PCIe controller")
Cc: stable@vger.kernel.org
Signed-off-by: Rick Wertenbroek <rick.wertenbroek@gmail.com>
---
 drivers/pci/controller/pcie-rockchip-ep.c | 45 ++++++-----------------
 drivers/pci/controller/pcie-rockchip.h    |  6 ++-
 2 files changed, 16 insertions(+), 35 deletions(-)

diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
index 4c84e403e155..7591a7be78e0 100644
--- a/drivers/pci/controller/pcie-rockchip-ep.c
+++ b/drivers/pci/controller/pcie-rockchip-ep.c
@@ -337,48 +337,25 @@ static int rockchip_pcie_ep_get_msi(struct pci_epc *epc, u8 fn, u8 vfn)
 }
 
 static void rockchip_pcie_ep_assert_intx(struct rockchip_pcie_ep *ep, u8 fn,
-					 u8 intx, bool is_asserted)
+					 u8 intx, bool do_assert)
 {
 	struct rockchip_pcie *rockchip = &ep->rockchip;
-	u32 r = ep->max_regions - 1;
-	u32 offset;
-	u32 status;
-	u8 msg_code;
-
-	if (unlikely(ep->irq_pci_addr != ROCKCHIP_PCIE_EP_PCI_LEGACY_IRQ_ADDR ||
-		     ep->irq_pci_fn != fn)) {
-		rockchip_pcie_prog_ep_ob_atu(rockchip, fn, r,
-					     AXI_WRAPPER_NOR_MSG,
-					     ep->irq_phys_addr, 0, 0);
-		ep->irq_pci_addr = ROCKCHIP_PCIE_EP_PCI_LEGACY_IRQ_ADDR;
-		ep->irq_pci_fn = fn;
-	}
 
 	intx &= 3;
-	if (is_asserted) {
+
+	if (do_assert) {
 		ep->irq_pending |= BIT(intx);
-		msg_code = ROCKCHIP_PCIE_MSG_CODE_ASSERT_INTA + intx;
+		rockchip_pcie_write(rockchip,
+				    PCIE_CLIENT_INT_IN_ASSERT |
+				    PCIE_CLIENT_INT_PEND_ST_PEND,
+				    PCIE_CLIENT_LEGACY_INT_CTRL);
 	} else {
 		ep->irq_pending &= ~BIT(intx);
-		msg_code = ROCKCHIP_PCIE_MSG_CODE_DEASSERT_INTA + intx;
+		rockchip_pcie_write(rockchip,
+				    PCIE_CLIENT_INT_IN_DEASSERT |
+				    PCIE_CLIENT_INT_PEND_ST_NORMAL,
+				    PCIE_CLIENT_LEGACY_INT_CTRL);
 	}
-
-	status = rockchip_pcie_read(rockchip,
-				    ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
-				    ROCKCHIP_PCIE_EP_CMD_STATUS);
-	status &= ROCKCHIP_PCIE_EP_CMD_STATUS_IS;
-
-	if ((status != 0) ^ (ep->irq_pending != 0)) {
-		status ^= ROCKCHIP_PCIE_EP_CMD_STATUS_IS;
-		rockchip_pcie_write(rockchip, status,
-				    ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
-				    ROCKCHIP_PCIE_EP_CMD_STATUS);
-	}
-
-	offset =
-	   ROCKCHIP_PCIE_MSG_ROUTING(ROCKCHIP_PCIE_MSG_ROUTING_LOCAL_INTX) |
-	   ROCKCHIP_PCIE_MSG_CODE(msg_code) | ROCKCHIP_PCIE_MSG_NO_DATA;
-	writel(0, ep->irq_cpu_addr + offset);
 }
 
 static int rockchip_pcie_ep_send_legacy_irq(struct rockchip_pcie_ep *ep, u8 fn,
diff --git a/drivers/pci/controller/pcie-rockchip.h b/drivers/pci/controller/pcie-rockchip.h
index f3a5ff1cf7f4..ffc68a3a5fee 100644
--- a/drivers/pci/controller/pcie-rockchip.h
+++ b/drivers/pci/controller/pcie-rockchip.h
@@ -38,6 +38,11 @@
 #define   PCIE_CLIENT_MODE_EP            HIWORD_UPDATE(0x0040, 0)
 #define   PCIE_CLIENT_GEN_SEL_1		  HIWORD_UPDATE(0x0080, 0)
 #define   PCIE_CLIENT_GEN_SEL_2		  HIWORD_UPDATE_BIT(0x0080)
+#define PCIE_CLIENT_LEGACY_INT_CTRL	(PCIE_CLIENT_BASE + 0x0c)
+#define   PCIE_CLIENT_INT_IN_ASSERT		HIWORD_UPDATE_BIT(0x0002)
+#define   PCIE_CLIENT_INT_IN_DEASSERT		HIWORD_UPDATE(0x0002, 0)
+#define   PCIE_CLIENT_INT_PEND_ST_PEND		HIWORD_UPDATE_BIT(0x0001)
+#define   PCIE_CLIENT_INT_PEND_ST_NORMAL	HIWORD_UPDATE(0x0001, 0)
 #define PCIE_CLIENT_SIDE_BAND_STATUS	(PCIE_CLIENT_BASE + 0x20)
 #define   PCIE_CLIENT_PHY_ST			BIT(12)
 #define PCIE_CLIENT_DEBUG_OUT_0		(PCIE_CLIENT_BASE + 0x3c)
@@ -227,7 +232,6 @@
 #define   ROCKCHIP_PCIE_EP_MSI_CTRL_ME				BIT(16)
 #define   ROCKCHIP_PCIE_EP_MSI_CTRL_MASK_MSI_CAP	BIT(24)
 #define ROCKCHIP_PCIE_EP_DUMMY_IRQ_ADDR				0x1
-#define ROCKCHIP_PCIE_EP_PCI_LEGACY_IRQ_ADDR		0x3
 #define ROCKCHIP_PCIE_EP_FUNC_BASE(fn)	(((fn) << 12) & GENMASK(19, 12))
 #define ROCKCHIP_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar) \
 	(PCIE_RC_RP_ATS_BASE + 0x0840 + (fn) * 0x0040 + (bar) * 0x0008)
-- 
2.25.1