[RFC PATCH v2 10/11] irqchip: mbigen: Add ACPI support

[Hanjun Guo <guohanjun@huawei.com>]

From: Hanjun Guo <hanjun.guo@linaro.org>

With the preparation of platform msi support and interrupt producer
in DSDT, we can add mbigen ACPI support now.

We are using _PRS methd to indicate number of irq pins instead
of num_pins in DT.

For mbi-gen,
    Device(MBI0) {
          Name(_HID, "HISI0152")
          Name(_UID, Zero)
          Name(_CRS, ResourceTemplate() {
                  Memory32Fixed(ReadWrite, 0xa0080000, 0x10000)
          })

          Name (_PRS, ResourceTemplate() {
		  Interrupt(ResourceProducer,...) {12,14,....}
          })
    }

For devices,

   Device(COM0) {
          Name(_HID, "ACPIIDxx")
          Name(_UID, Zero)
          Name(_CRS, ResourceTemplate() {
                 Memory32Fixed(ReadWrite, 0xb0030000, 0x10000)
		 Interrupt(ResourceConsumer,..., "\_SB.MBI0") {12}
          })
    }

With the helpe of platform msi and interrupt producer, then devices
will get the virq from mbi-gen's irqdomain.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ma Jun <majun258@huawei.com>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
---
 drivers/irqchip/irq-mbigen.c | 70 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 67 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-mbigen.c b/drivers/irqchip/irq-mbigen.c
index 9484ea0..ca6add1 100644
--- a/drivers/irqchip/irq-mbigen.c
+++ b/drivers/irqchip/irq-mbigen.c
@@ -16,6 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/acpi.h>
 #include <linux/interrupt.h>
 #include <linux/irqchip.h>
 #include <linux/module.h>
@@ -180,7 +181,7 @@ static int mbigen_domain_translate(struct irq_domain *d,
 				    unsigned long *hwirq,
 				    unsigned int *type)
 {
-	if (is_of_node(fwspec->fwnode)) {
+	if (is_of_node(fwspec->fwnode) || is_acpi_device_node(fwspec->fwnode)) {
 		if (fwspec->param_count != 2)
 			return -EINVAL;
 
@@ -271,6 +272,54 @@ static int mbigen_of_create_domain(struct platform_device *pdev,
 	return 0;
 }
 
+#ifdef CONFIG_ACPI
+static acpi_status mbigen_acpi_process_resource(struct acpi_resource *ares,
+					     void *context)
+{
+	struct acpi_resource_extended_irq *ext_irq;
+	u32 *num_irqs = context;
+
+	switch (ares->type) {
+	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
+		ext_irq = &ares->data.extended_irq;
+		*num_irqs += ext_irq->interrupt_count;
+		break;
+	default:
+		break;
+	}
+
+	return AE_OK;
+}
+
+static int mbigen_acpi_create_domain(struct platform_device *pdev,
+				     struct mbigen_device *mgn_chip)
+{
+	struct irq_domain *domain;
+	u32 num_msis = 0;
+	acpi_status status;
+
+	status = acpi_walk_resources(ACPI_HANDLE(&pdev->dev), METHOD_NAME__PRS,
+				     mbigen_acpi_process_resource, &num_msis);
+        if (ACPI_FAILURE(status) || num_msis == 0)
+		return -EINVAL;
+
+	domain = platform_msi_create_device_domain(&pdev->dev, num_msis,
+						   mbigen_write_msg,
+						   &mbigen_domain_ops,
+						   mgn_chip);
+	if (!domain)
+		return -ENOMEM;
+
+	return 0;
+}
+#else
+static int mbigen_acpi_create_domain(struct platform_device *pdev,
+				     struct mbigen_device *mgn_chip)
+{
+	return -ENODEV;
+}
+#endif
+
 static int mbigen_device_probe(struct platform_device *pdev)
 {
 	struct mbigen_device *mgn_chip;
@@ -288,9 +337,17 @@ static int mbigen_device_probe(struct platform_device *pdev)
 	if (IS_ERR(mgn_chip->base))
 		return PTR_ERR(mgn_chip->base);
 
-	err = mbigen_of_create_domain(pdev, mgn_chip);
-	if (err)
+	if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node)
+		err = mbigen_of_create_domain(pdev, mgn_chip);
+	else if (ACPI_COMPANION(&pdev->dev))
+		err = mbigen_acpi_create_domain(pdev, mgn_chip);
+	else
+		err = -EINVAL;
+
+	if (err) {
+		dev_err(&pdev->dev, "Failed to create mbi-gen@%p irqdomain", mgn_chip->base);
 		return err;
+	}
 
 	platform_set_drvdata(pdev, mgn_chip);
 	return 0;
@@ -302,10 +359,17 @@ static const struct of_device_id mbigen_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, mbigen_of_match);
 
+static const struct acpi_device_id mbigen_acpi_match[] = {
+        { "HISI0152", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, mbigen_acpi_match);
+
 static struct platform_driver mbigen_platform_driver = {
 	.driver = {
 		.name		= "Hisilicon MBIGEN-V2",
 		.of_match_table	= mbigen_of_match,
+		.acpi_match_table = ACPI_PTR(mbigen_acpi_match),
 	},
 	.probe			= mbigen_device_probe,
 };
-- 
1.7.12.4