[RFC PATCH] GPIO/ACPI: DesignWare: Add GPIO-signaled ACPI events support for power button

[qiujiang <qiujiang@xxxxxxxxxx>]

This patch modifies the DesignWare GPIO controller driver to
support the GPIO-signaled ACPI Events. This is used for power
button function on ARM server.

To make it work, the _AEI and _EVT object must be defined in
the corresponding GPIO driver's dsdt table in UEFI. At the same
time, ACPI daemon component is also necessary.

Signed-off-by: qiujiang <qiujiang@xxxxxxxxxx>
---
 drivers/gpio/gpio-dwapb.c                | 75 ++++++++++++++++++++------------
 include/linux/platform_data/gpio-dwapb.h |  2 +-
 2 files changed, 49 insertions(+), 28 deletions(-)

diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
index fcd5b0a..bfed2e9 100644
--- a/drivers/gpio/gpio-dwapb.c
+++ b/drivers/gpio/gpio-dwapb.c
@@ -23,6 +23,11 @@
 #include <linux/spinlock.h>
 #include <linux/platform_data/gpio-dwapb.h>
 #include <linux/slab.h>
+#include <linux/acpi.h>
+#include <linux/gpio.h>
+
+#include "gpiolib.h"
+
 
 #define GPIO_SWPORTA_DR		0x00
 #define GPIO_SWPORTA_DDR	0x04
@@ -296,14 +301,14 @@ static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
 				 struct dwapb_port_property *pp)
 {
 	struct gpio_chip *gc = &port->bgc.gc;
-	struct device_node *node = pp->node;
+	struct fwnode_handle  *fwnode = pp->fwnode;
 	struct irq_chip_generic	*irq_gc = NULL;
 	unsigned int hwirq, ngpio = gc->ngpio;
 	struct irq_chip_type *ct;
 	int err, i;
 
-	gpio->domain = irq_domain_add_linear(node, ngpio,
-					     &irq_generic_chip_ops, gpio);
+	gpio->domain = irq_domain_create_linear(fwnode,
+				ngpio, &irq_generic_chip_ops, gpio);
 	if (!gpio->domain)
 		return;
 
@@ -421,7 +426,7 @@ static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
 	}
 
 #ifdef CONFIG_OF_GPIO
-	port->bgc.gc.of_node = pp->node;
+	port->bgc.gc.of_node = to_of_node(pp->fwnode);
 #endif
 	port->bgc.gc.ngpio = pp->ngpio;
 	port->bgc.gc.base = pp->gpio_base;
@@ -440,6 +445,10 @@ static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
 	else
 		port->is_registered = true;
 
+	/* Add GPIO-signaled ACPI event support */
+	if (pp->irq)
+		acpi_gpiochip_request_interrupts(&(port->bgc.gc));
+
 	return err;
 }
 
@@ -453,19 +462,15 @@ static void dwapb_gpio_unregister(struct dwapb_gpio *gpio)
 }
 
 static struct dwapb_platform_data *
-dwapb_gpio_get_pdata_of(struct device *dev)
+dwapb_gpio_get_pdata(struct device *dev)
 {
-	struct device_node *node, *port_np;
+	struct fwnode_handle *fwnode;
 	struct dwapb_platform_data *pdata;
 	struct dwapb_port_property *pp;
 	int nports;
 	int i;
 
-	node = dev->of_node;
-	if (!IS_ENABLED(CONFIG_OF_GPIO) || !node)
-		return ERR_PTR(-ENODEV);
-
-	nports = of_get_child_count(node);
+	nports = device_get_child_node_count(dev);
 	if (nports == 0)
 		return ERR_PTR(-ENODEV);
 
@@ -480,21 +485,19 @@ dwapb_gpio_get_pdata_of(struct device *dev)
 	pdata->nports = nports;
 
 	i = 0;
-	for_each_child_of_node(node, port_np) {
-		pp = &pdata->properties[i++];
-		pp->node = port_np;
+	device_for_each_child_node(dev, fwnode) {
+		pp = &pdata->properties[i];
+		pp->fwnode = fwnode;
 
-		if (of_property_read_u32(port_np, "reg", &pp->idx) ||
+		if (fwnode_property_read_u32(fwnode, "reg", &pp->idx) ||
 		    pp->idx >= DWAPB_MAX_PORTS) {
-			dev_err(dev, "missing/invalid port index for %s\n",
-				port_np->full_name);
+			dev_err(dev, "missing/invalid port index\n");
 			return ERR_PTR(-EINVAL);
 		}
 
-		if (of_property_read_u32(port_np, "snps,nr-gpios",
+		if (fwnode_property_read_u32(fwnode, "snps,nr-gpios",
 					 &pp->ngpio)) {
-			dev_info(dev, "failed to get number of gpios for %s\n",
-				 port_np->full_name);
+			dev_info(dev, "failed to get number of gpios\n");
 			pp->ngpio = 32;
 		}
 
@@ -502,18 +505,27 @@ dwapb_gpio_get_pdata_of(struct device *dev)
 		 * Only port A can provide interrupts in all configurations of
 		 * the IP.
 		 */
-		if (pp->idx == 0 &&
-		    of_property_read_bool(port_np, "interrupt-controller")) {
-			pp->irq = irq_of_parse_and_map(port_np, 0);
+		 if (dev->of_node && pp->idx == 0 &&
+			 of_property_read_bool(to_of_node(fwnode),
+			 "interrupt-controller")) {
+			pp->irq = irq_of_parse_and_map(to_of_node(fwnode), 0);
 			if (!pp->irq) {
-				dev_warn(dev, "no irq for bank %s\n",
-					 port_np->full_name);
+			dev_warn(dev, "no irq for bank %s\n",
+				  to_of_node(fwnode)->full_name);
 			}
 		}
 
+		if (ACPI_COMPANION(dev) && pp->idx == 0)
+			pp->irq = platform_get_irq(to_platform_device(dev), 0);
+
 		pp->irq_shared	= false;
 		pp->gpio_base	= -1;
-		pp->name	= port_np->full_name;
+
+		if (dev->of_node)
+			pp->name = to_of_node(fwnode)->full_name;
+
+		if (ACPI_COMPANION(dev))
+			pp->name = acpi_dev_name(to_acpi_device_node(fwnode));
 	}
 
 	return pdata;
@@ -529,7 +541,7 @@ static int dwapb_gpio_probe(struct platform_device *pdev)
 	struct dwapb_platform_data *pdata = dev_get_platdata(dev);
 
 	if (!pdata) {
-		pdata = dwapb_gpio_get_pdata_of(dev);
+		pdata = dwapb_gpio_get_pdata(dev);
 		if (IS_ERR(pdata))
 			return PTR_ERR(pdata);
 	}
@@ -559,6 +571,7 @@ static int dwapb_gpio_probe(struct platform_device *pdev)
 		if (err)
 			goto out_unregister;
 	}
+
 	platform_set_drvdata(pdev, gpio);
 
 	return 0;
@@ -586,6 +599,13 @@ static const struct of_device_id dwapb_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, dwapb_of_match);
 
+static const struct acpi_device_id dwapb_acpi_match[] = {
+		{"HISI0181", 0},
+		{ }
+};
+MODULE_DEVICE_TABLE(acpi, dwapb_acpi_match);
+
+
 #ifdef CONFIG_PM_SLEEP
 static int dwapb_gpio_suspend(struct device *dev)
 {
@@ -680,6 +700,7 @@ static struct platform_driver dwapb_gpio_driver = {
 		.name	= "gpio-dwapb",
 		.pm	= &dwapb_gpio_pm_ops,
 		.of_match_table = of_match_ptr(dwapb_of_match),
+		.acpi_match_table = ACPI_PTR(dwapb_acpi_match),
 	},
 	.probe		= dwapb_gpio_probe,
 	.remove		= dwapb_gpio_remove,
diff --git a/include/linux/platform_data/gpio-dwapb.h b/include/linux/platform_data/gpio-dwapb.h
index 28702c8..c5bd1f2 100644
--- a/include/linux/platform_data/gpio-dwapb.h
+++ b/include/linux/platform_data/gpio-dwapb.h
@@ -15,7 +15,7 @@
 #define GPIO_DW_APB_H
 
 struct dwapb_port_property {
-	struct device_node *node;
+	struct fwnode_handle *fwnode;
 	const char	*name;
 	unsigned int	idx;
 	unsigned int	ngpio;
-- 
1.9.1

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