[PATCH v2 7/9] PCI: rockchip: Fix legacy IRQ generation for RK3399 PCIe endpoint core

[Rick Wertenbroek <rick.wertenbroek@xxxxxxxxx>]

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@xxxxxxxxxxxxxxx
Signed-off-by: Rick Wertenbroek <rick.wertenbroek@xxxxxxxxx>
---
 drivers/pci/controller/pcie-rockchip-ep.c | 38 +++++------------------
 drivers/pci/controller/pcie-rockchip.h    |  6 ++++
 2 files changed, 14 insertions(+), 30 deletions(-)

diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
index cbc281a6a..ca5b363ba 100644
--- a/drivers/pci/controller/pcie-rockchip-ep.c
+++ b/drivers/pci/controller/pcie-rockchip-ep.c
@@ -328,45 +328,23 @@ static void rockchip_pcie_ep_assert_intx(struct rockchip_pcie_ep *ep, u8 fn,
 					 u8 intx, bool is_asserted)
 {
 	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) {
 		ep->irq_pending |= BIT(intx);
-		msg_code = ROCKCHIP_PCIE_MSG_CODE_ASSERT_INTA + intx;
 	} else {
 		ep->irq_pending &= ~BIT(intx);
-		msg_code = ROCKCHIP_PCIE_MSG_CODE_DEASSERT_INTA + intx;
 	}
 
-	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);
+	if (is_asserted) {
+		rockchip_pcie_write(rockchip,
+			PCIE_CLIENT_INT_IN_ASSERT | PCIE_CLIENT_INT_PEND_ST_PEND,
+			PCIE_CLIENT_LEGACY_INT_CTRL);
+	} else {
+		rockchip_pcie_write(rockchip,
+			PCIE_CLIENT_INT_IN_DEASSERT | PCIE_CLIENT_INT_PEND_ST_NORMAL,
+			PCIE_CLIENT_LEGACY_INT_CTRL);
 	}
-
-	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 72e427a0f..e90c2a2b8 100644
--- a/drivers/pci/controller/pcie-rockchip.h
+++ b/drivers/pci/controller/pcie-rockchip.h
@@ -39,6 +39,12 @@
 #define   PCIE_CLIENT_GEN_SEL_1		  HIWORD_UPDATE(0x0080, 0)
 #define   PCIE_CLIENT_GEN_SEL_2		  HIWORD_UPDATE_BIT(0x0080)
 #define PCIE_CLIENT_SIDE_BAND_STATUS	(PCIE_CLIENT_BASE + 0x20)
+#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)
 #define   PCIE_CLIENT_DEBUG_LTSSM_MASK		GENMASK(5, 0)
-- 
2.25.1