tps65217: Enable KEY_POWER press on AC loss / PWR_BUT

Adaption of the original patch by Andrew Bradford <andrew.bradford@omni-id.com>
Some minor devm_* changes and DT support.

Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>

drivers/mfd/tps65217.c

@@ -26,6 +26,9 @@
 #include <linux/err.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/of_gpio.h>
+#include <linux/interrupt.h>
 
 #include <linux/mfd/core.h>
 #include <linux/mfd/tps65217.h>
@@ -153,26 +156,128 @@ static const struct of_device_id tps65217_of_match[] = {
 	{ /* sentinel */ },
 };
 
+static irqreturn_t tps65217_irq(int irq, void *irq_data)
+{
+        struct tps65217 *tps = irq_data;
+        unsigned int int_reg = 0, status_reg = 0;
+
+        tps65217_reg_read(tps, TPS65217_REG_INT, &int_reg);
+        tps65217_reg_read(tps, TPS65217_REG_STATUS, &status_reg);
+        if (status_reg)
+                dev_dbg(tps->dev, "status now: 0x%X\n", status_reg);
+
+        if (!int_reg)
+                return IRQ_NONE;
+
+        if (int_reg & TPS65217_INT_PBI) {
+                /* Handle push button */
+                dev_dbg(tps->dev, "power button status change\n");
+                input_report_key(tps->pwr_but, KEY_POWER,
+                                status_reg & TPS65217_STATUS_PB);
+                input_sync(tps->pwr_but);
+        }
+        if (int_reg & TPS65217_INT_ACI) {
+                /* Handle AC power status change */
+                dev_dbg(tps->dev, "AC power status change\n");
+                /* Press KEY_POWER when AC not present */
+                input_report_key(tps->pwr_but, KEY_POWER,
+                                ~status_reg & TPS65217_STATUS_ACPWR);
+                input_sync(tps->pwr_but);
+        }
+        if (int_reg & TPS65217_INT_USBI) {
+                /* Handle USB power status change */
+                dev_dbg(tps->dev, "USB power status change\n");
+        }
+
+        return IRQ_HANDLED;
+}
+
+static int tps65217_probe_pwr_but(struct tps65217 *tps)
+{
+	int ret;
+        unsigned int int_reg;
+
+	tps->pwr_but = devm_input_allocate_device(tps->dev);
+	if (!tps->pwr_but) {
+		dev_err(tps->dev,
+			"Failed to allocated pwr_but input device\n");
+		return -ENOMEM;
+	}
+
+	tps->pwr_but->evbit[0] = BIT_MASK(EV_KEY);
+	tps->pwr_but->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
+	tps->pwr_but->name = "tps65217_pwr_but";
+	ret = input_register_device(tps->pwr_but);
+	if (ret) {
+		/* NOTE: devm managed device */
+		dev_err(tps->dev, "Failed to register button device\n");
+		return ret;
+	}
+	ret = devm_request_threaded_irq(tps->dev,
+		tps->irq, NULL, tps65217_irq, IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+		"tps65217", tps);
+	if (ret != 0) {
+		dev_err(tps->dev, "Failed to request IRQ %d\n", tps->irq);
+		return ret;
+	}
+
+	/* enable the power button interrupt */
+	ret = tps65217_reg_read(tps, TPS65217_REG_INT, &int_reg);
+	if (ret < 0) {
+		dev_err(tps->dev, "Failed to read INT reg\n");
+		return ret;
+	}
+	int_reg &= ~TPS65217_INT_PBM;
+	tps65217_reg_write(tps, TPS65217_REG_INT, int_reg, TPS65217_PROTECT_NONE);
+	return 0;
+}
+
 static int tps65217_probe(struct i2c_client *client,
 				const struct i2c_device_id *ids)
 {
 	struct tps65217 *tps;
 	unsigned int version;
 	unsigned int chip_id = ids->driver_data;
 	const struct of_device_id *match;
+	struct device_node *node;
 	bool status_off = false;
+	int irq = -1, irq_gpio = -1;
 	int ret;
 
-	if (client->dev.of_node) {
+	node = client->dev.of_node;
+	if (node) {
 		match = of_match_device(tps65217_of_match, &client->dev);
 		if (!match) {
 			dev_err(&client->dev,
 				"Failed to find matching dt id\n");
 			return -EINVAL;
 		}
 		chip_id = (unsigned int)match->data;
-		status_off = of_property_read_bool(client->dev.of_node,
+		status_off = of_property_read_bool(node,
 					"ti,pmic-shutdown-controller");
+
+		/* at first try to get irq via OF method */
+		irq = irq_of_parse_and_map(node, 0);
+		if (irq <= 0) {
+			irq = -1;
+			irq_gpio = of_get_named_gpio(node, "irq-gpio", 0);
+			if (irq_gpio >= 0) {
+				/* valid gpio; convert to irq */
+				ret = devm_gpio_request_one(&client->dev,
+					irq_gpio, GPIOF_DIR_IN,
+					"tps65217-gpio-irq");
+				if (ret != 0)
+					dev_warn(&client->dev, "Failed to "
+						"request gpio #%d\n", irq_gpio);
+				irq = gpio_to_irq(irq_gpio);
+				if (irq <= 0) {
+					dev_warn(&client->dev, "Failed to "
+						"convert gpio #%d to irq\n",
+						irq_gpio);
+					irq = -1;
+				}
+			}
+		}
 	}
 
 	if (!chip_id) {
@@ -196,6 +301,18 @@ static int tps65217_probe(struct i2c_client *client,
 		return ret;
 	}
 
+	tps->irq = irq;
+	tps->irq_gpio = irq_gpio;
+
+	/* we got an irq, request it */
+	if (tps->irq >= 0) {
+		ret = tps65217_probe_pwr_but(tps);
+		if (ret < 0) {
+			dev_err(tps->dev, "Failed to probe pwr_but\n");
+			return ret;
+		}
+	}
+
 	ret = mfd_add_devices(tps->dev, -1, tps65217s,
 			      ARRAY_SIZE(tps65217s), NULL, 0, NULL);
 	if (ret < 0) {

include/linux/mfd/tps65217.h

@@ -21,6 +21,7 @@
 #include <linux/i2c.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
+#include <linux/input.h>
 
 /* TPS chip id list */
 #define TPS65217			0xF0
@@ -274,6 +275,11 @@ struct tps65217 {
 	struct regulator_dev *rdev[TPS65217_NUM_REGULATOR];
 	struct tps_info *info[TPS65217_NUM_REGULATOR];
 	struct regmap *regmap;
+
+	/* Power button and IRQ handling */
+	int irq_gpio;	/* might not be set */
+	int irq;
+	struct input_dev *pwr_but;
 };
 
 static inline struct tps65217 *dev_to_tps65217(struct device *dev)