[v6,13/17] memory: omap-gpmc: Support general purpose input for WAITPINs

diff --git a/Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt b/Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt
index 13f1378..97e7192 100644
--- a/Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt
+++ b/Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt
@@ -38,6 +38,10 @@  Required properties:
 			0 - NAND_fifoevent
 			1 - NAND_termcount
  - interrupt-cells:	Must be set to 2
+ - gpio-controller:	The GPMC driver implements a GPIO controller for the
+			GPMC WAIT pins that can be used as general purpose inputs.
+			0 maps to GPMC_WAIT0 pin.
+ - gpio-cells:		Must be set to 2
 
 Timing properties for child nodes. All are optional and default to 0.
 
@@ -138,6 +142,8 @@  Example for an AM33xx board:
 		ranges = <0 0 0x08000000 0x10000000>; /* CS0 @addr 0x8000000, size 0x10000000 */
 		interrupt-controller;
 		#interrupt-cells = <2>;
+		gpio-controller;
+		#gpio-cells = <2>;
 
 		/* child nodes go here */
 	};
diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index 51d5cd2..a9b1c14 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -51,6 +51,7 @@  config TI_EMIF
 
 config OMAP_GPMC
 	bool
+	select GPIOLIB
 	help
 	  This driver is for the General Purpose Memory Controller (GPMC)
 	  present on Texas Instruments SoCs (e.g. OMAP2+). GPMC allows
diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
index bfe4e87..4dd1c65 100644
--- a/drivers/memory/omap-gpmc.c
+++ b/drivers/memory/omap-gpmc.c
@@ -21,6 +21,7 @@ 
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/module.h>
+#include <linux/gpio/driver.h>
 #include <linux/interrupt.h>
 #include <linux/irqdomain.h>
 #include <linux/platform_device.h>
@@ -237,6 +238,7 @@  struct gpmc_device {
 	struct device *dev;
 	int irq;
 	struct irq_chip irq_chip;
+	struct gpio_chip gpio_chip;
 };
 
 static struct irq_domain *gpmc_irq_domain;
@@ -2064,10 +2066,71 @@  err:
 	return ret;
 }
 
+static int gpmc_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
+{
+	return 1;	/* we're input only */
+}
+
+static int gpmc_gpio_direction_input(struct gpio_chip *chip,
+				     unsigned int offset)
+{
+	return 0;	/* we're input only */
+}
+
+static int gpmc_gpio_direction_output(struct gpio_chip *chip,
+				      unsigned int offset, int value)
+{
+	return -EINVAL;	/* we're input only */
+}
+
+static void gpmc_gpio_set(struct gpio_chip *chip, unsigned int offset,
+			  int value)
+{
+}
+
+static int gpmc_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	u32 reg;
+
+	offset += 8;
+
+	reg = gpmc_read_reg(GPMC_STATUS) & BIT(offset);
+
+	return !!reg;
+}
+
+static int gpmc_gpio_init(struct gpmc_device *gpmc)
+{
+	int ret;
+
+	gpmc->gpio_chip.parent = gpmc->dev;
+	gpmc->gpio_chip.owner = THIS_MODULE;
+	gpmc->gpio_chip.label = DEVICE_NAME;
+	gpmc->gpio_chip.ngpio = gpmc_nr_waitpins;
+	gpmc->gpio_chip.get_direction = gpmc_gpio_get_direction;
+	gpmc->gpio_chip.direction_input = gpmc_gpio_direction_input;
+	gpmc->gpio_chip.direction_output = gpmc_gpio_direction_output;
+	gpmc->gpio_chip.set = gpmc_gpio_set;
+	gpmc->gpio_chip.get = gpmc_gpio_get;
+	gpmc->gpio_chip.base = -1;
+
+	ret = gpiochip_add(&gpmc->gpio_chip);
+	if (ret < 0) {
+		dev_err(gpmc->dev, "could not register gpio chip: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void gpmc_gpio_exit(struct gpmc_device *gpmc)
+{
+	gpiochip_remove(&gpmc->gpio_chip);
+}
+
 static int gpmc_probe_dt(struct platform_device *pdev)
 {
 	int ret;
-	struct device_node *child;
 	const struct of_device_id *of_id =
 		of_match_device(gpmc_dt_ids, &pdev->dev);
 
@@ -2095,6 +2158,14 @@  static int gpmc_probe_dt(struct platform_device *pdev)
 		return ret;
 	}
 
+	return 0;
+}
+
+static int gpmc_probe_dt_children(struct platform_device *pdev)
+{
+	int ret;
+	struct device_node *child;
+
 	for_each_available_child_of_node(pdev->dev.of_node, child) {
 
 		if (!child->name)
@@ -2104,6 +2175,9 @@  static int gpmc_probe_dt(struct platform_device *pdev)
 			ret = gpmc_probe_onenand_child(pdev, child);
 		else
 			ret = gpmc_probe_generic_child(pdev, child);
+
+		if (ret)
+			return ret;
 	}
 
 	return 0;
@@ -2113,6 +2187,11 @@  static int gpmc_probe_dt(struct platform_device *pdev)
 {
 	return 0;
 }
+
+static int gpmc_probe_dt_children(struct platform_device *pdev)
+{
+	return 0;
+}
 #endif
 
 static int gpmc_probe(struct platform_device *pdev)
@@ -2159,6 +2238,15 @@  static int gpmc_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	if (pdev->dev.of_node) {
+		rc = gpmc_probe_dt(pdev);
+		if (rc)
+			return rc;
+	} else {
+		gpmc_cs_num = GPMC_CS_NUM;
+		gpmc_nr_waitpins = GPMC_NR_WAITPINS;
+	}
+
 	pm_runtime_enable(&pdev->dev);
 	pm_runtime_get_sync(&pdev->dev);
 
@@ -2184,29 +2272,33 @@  static int gpmc_probe(struct platform_device *pdev)
 		 GPMC_REVISION_MINOR(l));
 
 	gpmc_mem_init();
+	rc = gpmc_gpio_init(gpmc);
+	if (rc)
+		goto gpio_init_failed;
 
 	rc = gpmc_setup_irq(gpmc);
 	if (rc) {
 		dev_err(gpmc->dev, "gpmc_setup_irq failed\n");
-		goto fail;
+		goto setup_irq_failed;
 	}
 
-	if (!pdev->dev.of_node) {
-		gpmc_cs_num	 = GPMC_CS_NUM;
-		gpmc_nr_waitpins = GPMC_NR_WAITPINS;
-	}
-
-	rc = gpmc_probe_dt(pdev);
+	rc = gpmc_probe_dt_children(pdev);
 	if (rc < 0) {
-		dev_err(gpmc->dev, "failed to probe DT parameters\n");
-		gpmc_free_irq(gpmc);
-		goto fail;
+		dev_err(gpmc->dev, "failed to probe DT children\n");
+		goto dt_children_failed;
 	}
 
 	return 0;
 
-fail:
+dt_children_failed:
+	gpmc_free_irq(gpmc);
+setup_irq_failed:
+	gpmc_gpio_exit(gpmc);
+gpio_init_failed:
+	gpmc_mem_exit();
 	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
 	return rc;
 }
 
@@ -2215,6 +2307,7 @@  static int gpmc_remove(struct platform_device *pdev)
 	struct gpmc_device *gpmc = platform_get_drvdata(pdev);
 
 	gpmc_free_irq(gpmc);
+	gpmc_gpio_exit(gpmc);
 	gpmc_mem_exit();
 	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);