[PATCH 0/3] i.MX6 MSI support

[PATCH 0/3] i.MX6 MSI support

[Lucas Stach]

This adds MSI support to the i.MX6 PCIe host
controller driver. We keep MSI optional in order
to not break any existing DTs.

This series depends on the previous sent series
"PCI irq mapping fixes and cleanups".

Lucas Stach (3):
  ARM: dts: imx6: extend PCIe interrupt list for MSI
  PCI: designware: make MSI isr shared irq aware
  PCI: imx6: add support for MSI

 .../devicetree/bindings/pci/fsl,imx6q-pcie.txt     |  9 +++++++-
 arch/arm/boot/dts/imx6qdl.dtsi                     |  4 +++-
 drivers/pci/host/pci-exynos.c                      |  4 +---
 drivers/pci/host/pci-imx6.c                        | 26 ++++++++++++++++++++++
 drivers/pci/host/pcie-designware.c                 |  6 ++++-
 drivers/pci/host/pcie-designware.h                 |  2 +-
 6 files changed, 44 insertions(+), 7 deletions(-)

-- 
1.8.5.3

[PATCH 1/3] ARM: dts: imx6: extend PCIe interrupt list for MSI

[Lucas Stach]

Optional IRQ necessary for handling MSI.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
 Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt | 9 ++++++++-
 arch/arm/boot/dts/imx6qdl.dtsi                           | 4 +++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
index 93fbfd62f13c..0515183a6d96 100644
--- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
@@ -17,6 +17,11 @@ Required properties:
 	- "pcie_axi"
 
 Optional properties:
+- interrupts: Must contain an entry for each entry in the
+  interrupt-names property.
+- interrupt-names: May include the following entries:
+	- "inta"
+	- "msi" if not present the driver won't be able to handle MSI
 - power-on-gpio: gpio pin number of power-enable signal
 - wake-up-gpio:  gpio pin number of incoming wakeup signal
 - disable-gpio:  gpio pin number of outgoing rfkill/endpoint disable signal
@@ -34,7 +39,9 @@ Example:
 			  0x82000000 0 0x01000000 0x01000000 0 0x00f00000>;
 		num-lanes = <1>;
 
-		interrupts = <0 123 0x04>;
+		interrupts = <GIC_SPI 123 IRQ_TYPE_LEVEL_HIGH>,
+		             <GIC_SPI 120 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-names = "inta", "msi";
 
 		#interrupt-cells = <1>;
 		interrupt-map-mask = <0 0 0 0x7>;
diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
index db3339e7d3a2..a3a3acd90964 100644
--- a/arch/arm/boot/dts/imx6qdl.dtsi
+++ b/arch/arm/boot/dts/imx6qdl.dtsi
@@ -129,7 +129,9 @@
 				  0x82000000 0 0x01000000 0x01000000 0 0x00f00000>; /* non-prefetchable memory */
 			num-lanes = <1>;
 
-			interrupts = <0 123 0x04>;
+			interrupts = <GIC_SPI 123 IRQ_TYPE_LEVEL_HIGH>,
+			             <GIC_SPI 120 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "inta", "msi";
 
 			#interrupt-cells = <1>;
 			interrupt-map-mask = <0 0 0 0x7>;
-- 
1.8.5.3

[PATCH 2/3] PCI: designware: make MSI isr shared irq aware

[Lucas Stach]

On i.MX6 the host controller MSI irq is shared
with PCI legacy INTD. Make sure we don't bail too
early from the irq handler.

The issue is fairly theoretical as it would require
a system setup with a PCIe switch where one connected
device is using legacy INTD and another one using
MSI, but better fix it now.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
 drivers/pci/host/pci-exynos.c      | 4 +---
 drivers/pci/host/pcie-designware.c | 6 +++++-
 drivers/pci/host/pcie-designware.h | 2 +-
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c
index 3de6bfbbe8e9..b616d34922d8 100644
--- a/drivers/pci/host/pci-exynos.c
+++ b/drivers/pci/host/pci-exynos.c
@@ -415,9 +415,7 @@ static irqreturn_t exynos_pcie_msi_irq_handler(int irq, void *arg)
 {
 	struct pcie_port *pp = arg;
 
-	dw_handle_msi_irq(pp);
-
-	return IRQ_HANDLED;
+	return dw_handle_msi_irq(pp);
 }
 
 static void exynos_pcie_msi_init(struct pcie_port *pp)
diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index 3e0c2af11528..f8c174a7d657 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -156,15 +156,17 @@ static struct irq_chip dw_msi_irq_chip = {
 };
 
 /* MSI int handler */
-void dw_handle_msi_irq(struct pcie_port *pp)
+irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
 {
 	unsigned long val;
 	int i, pos, irq;
+	irqreturn_t ret = IRQ_NONE;
 
 	for (i = 0; i < MAX_MSI_CTRLS; i++) {
 		dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_STATUS + i * 12, 4,
 				(u32 *)&val);
 		if (val) {
+			ret = IRQ_HANDLED;
 			pos = 0;
 			while ((pos = find_next_bit(&val, 32, pos)) != 32) {
 				irq = irq_find_mapping(pp->irq_domain,
@@ -177,6 +179,8 @@ void dw_handle_msi_irq(struct pcie_port *pp)
 			}
 		}
 	}
+
+	return ret;
 }
 
 void dw_pcie_msi_init(struct pcie_port *pp)
diff --git a/drivers/pci/host/pcie-designware.h b/drivers/pci/host/pcie-designware.h
index 3063b3594d88..a169d22d517e 100644
--- a/drivers/pci/host/pcie-designware.h
+++ b/drivers/pci/host/pcie-designware.h
@@ -68,7 +68,7 @@ struct pcie_host_ops {
 
 int dw_pcie_cfg_read(void __iomem *addr, int where, int size, u32 *val);
 int dw_pcie_cfg_write(void __iomem *addr, int where, int size, u32 val);
-void dw_handle_msi_irq(struct pcie_port *pp);
+irqreturn_t dw_handle_msi_irq(struct pcie_port *pp);
 void dw_pcie_msi_init(struct pcie_port *pp);
 int dw_pcie_link_up(struct pcie_port *pp);
 void dw_pcie_setup_rc(struct pcie_port *pp);
-- 
1.8.5.3

[PATCH 3/3] PCI: imx6: add support for MSI

[Lucas Stach]

This patch adds support for Message Signaled Interrupts in the
imx6-pcie driver.

Signed-off-by: Harro Haan <hrhaan@gmail.com>
Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
 drivers/pci/host/pci-imx6.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index e8663a8c3406..e038d47f1b01 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -25,6 +25,7 @@
 #include <linux/resource.h>
 #include <linux/signal.h>
 #include <linux/types.h>
+#include <linux/interrupt.h>
 
 #include "pcie-designware.h"
 
@@ -329,6 +330,13 @@ static int imx6_pcie_wait_for_link(struct pcie_port *pp)
 	return 0;
 }
 
+static irqreturn_t imx6_pcie_msi_handler(int irq, void *arg)
+{
+	struct pcie_port *pp = arg;
+
+	return dw_handle_msi_irq(pp);
+}
+
 static int imx6_pcie_start_link(struct pcie_port *pp)
 {
 	struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp);
@@ -403,6 +411,9 @@ static void imx6_pcie_host_init(struct pcie_port *pp)
 	dw_pcie_setup_rc(pp);
 
 	imx6_pcie_start_link(pp);
+
+	if (IS_ENABLED(CONFIG_PCI_MSI) && (pp->msi_irq > 0))
+		dw_pcie_msi_init(pp);
 }
 
 static void imx6_pcie_reset_phy(struct pcie_port *pp)
@@ -477,6 +488,21 @@ static int imx6_add_pcie_port(struct pcie_port *pp,
 		return -ENODEV;
 	}
 
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		pp->msi_irq = platform_get_irq_byname(pdev, "msi");
+		if (pp->msi_irq < 0) {
+			dev_info(&pdev->dev, "failed to get MSI irq, host will not support MSI\n");
+		} else {
+			ret = devm_request_irq(&pdev->dev, pp->msi_irq,
+			                       imx6_pcie_msi_handler,
+			                       IRQF_SHARED, "mx6-pcie-msi", pp);
+			if (ret) {
+				dev_err(&pdev->dev, "failed to request MSI irq\n");
+				return -ENODEV;
+			}
+		}
+	}
+
 	pp->root_bus_nr = -1;
 	pp->ops = &imx6_pcie_host_ops;
 
-- 
1.8.5.3

Re: [PATCH 1/3] ARM: dts: imx6: extend PCIe interrupt list for MSI

[Shawn Guo]

On Fri, Feb 28, 2014 at 06:30:31PM +0100, Lucas Stach wrote:
> Optional IRQ necessary for handling MSI.
> 
> Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> ---
>  Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt | 9 ++++++++-

Please have this change go with driver or a separate patch, not with
dts update.

Shawn

>  arch/arm/boot/dts/imx6qdl.dtsi                           | 4 +++-
>  2 files changed, 11 insertions(+), 2 deletions(-)