From ee99fe07a7dfaac187d56d518db3cb17cfe5634d Mon Sep 17 00:00:00 2001
From: Shawn Lin <shawn.lin@rock-chips.com>
Date: Tue, 16 Nov 2021 10:42:50 +0800
Subject: [PATCH] PCIe: rockchip:  Add more legacy int support

Some vendor drivers rely on flow control by toggling
enable/disable virtual irq if using legacy interrupt.
It can certainly change the behaviour by function
drivers, but adding corresponding operations would make
RC driver more flexible.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Change-Id: Idf3e6a0ca9c4ebde369745713a88db53e3f72ea5
---
 drivers/pci/controller/dwc/pcie-dw-rockchip.c | 36 ++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
index 07a0b0606a8f..d84c086aa200 100644
--- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
+++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
@@ -101,6 +101,8 @@ struct reset_bulk_data	{
 #define PCIE_CLIENT_INTR_STATUS_MISC	0x10
 #define PCIE_CLIENT_INTR_MASK_LEGACY	0x1c
 #define UNMASK_ALL_LEGACY_INT		0xffff0000
+#define MASK_LEGACY_INT(x)		(0x00110011 << x)
+#define UNMASK_LEGACY_INT(x)		(0x00110000 << x)
 #define PCIE_CLIENT_INTR_MASK		0x24
 #define PCIE_CLIENT_GENERAL_DEBUG	0x104
 #define PCIE_CLIENT_HOT_RESET_CTRL	0x180
@@ -156,6 +158,7 @@ struct rk_pcie {
 	bool				bifurcation;
 	struct regulator		*vpcie3v3;
 	struct irq_domain		*irq_domain;
+	raw_spinlock_t			intx_lock;
 };
 
 struct rk_pcie_of_data {
@@ -1490,10 +1493,41 @@ static void rk_pcie_fast_link_setup(struct rk_pcie *rk_pcie)
 	rk_pcie_writel_apb(rk_pcie, PCIE_CLIENT_HOT_RESET_CTRL, val);
 }
 
+static void rk_pcie_legacy_irq_mask(struct irq_data *d)
+{
+	struct rk_pcie *rk_pcie = irq_data_get_irq_chip_data(d);
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&rk_pcie->intx_lock, flags);
+	rk_pcie_writel_apb(rk_pcie, PCIE_CLIENT_INTR_MASK_LEGACY,
+			   MASK_LEGACY_INT(d->hwirq));
+	raw_spin_unlock_irqrestore(&rk_pcie->intx_lock, flags);
+}
+
+static void rk_pcie_legacy_irq_unmask(struct irq_data *d)
+{
+	struct rk_pcie *rk_pcie = irq_data_get_irq_chip_data(d);
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&rk_pcie->intx_lock, flags);
+	rk_pcie_writel_apb(rk_pcie, PCIE_CLIENT_INTR_MASK_LEGACY,
+			   UNMASK_LEGACY_INT(d->hwirq));
+	raw_spin_unlock_irqrestore(&rk_pcie->intx_lock, flags);
+}
+
+static struct irq_chip rk_pcie_legacy_irq_chip = {
+	.name		= "rk-pcie-legacy-int",
+	.irq_enable	= rk_pcie_legacy_irq_unmask,
+	.irq_disable	= rk_pcie_legacy_irq_mask,
+	.irq_mask	= rk_pcie_legacy_irq_mask,
+	.irq_unmask	= rk_pcie_legacy_irq_unmask,
+	.flags		= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND,
+};
+
 static int rk_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
 			    irq_hw_number_t hwirq)
 {
-	irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
+	irq_set_chip_and_handler(irq, &rk_pcie_legacy_irq_chip, handle_simple_irq);
 	irq_set_chip_data(irq, domain->host_data);
 
 	return 0;