[PATCH] mfd: palmas: Add support for optional wakeup

[Nishanth Menon <nm@ti.com>]

With the recent pinctrl-single changes, omaps can treat wake-up events
from deeper idle states as interrupts.

Let's add support for the optional second interrupt for wake-up
events. And then SoC can wakeup and handle the event using it's
regular handler.

Finally, to pass the wake-up interrupt in the dts file,
interrupts-extended property needs to be passed.

This is similar in approach to commit 2a0b965cfb6e ("serial: omap: Add
support for optional wake-up")

Signed-off-by: Nishanth Menon <nm@ti.com>
---
 Documentation/devicetree/bindings/mfd/palmas.txt |   20 ++++++++
 drivers/mfd/palmas.c                             |   59 ++++++++++++++++++++++
 include/linux/mfd/palmas.h                       |    2 +
 3 files changed, 81 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/palmas.txt b/Documentation/devicetree/bindings/mfd/palmas.txt
index eda8989..2627842 100644
--- a/Documentation/devicetree/bindings/mfd/palmas.txt
+++ b/Documentation/devicetree/bindings/mfd/palmas.txt
@@ -51,3 +51,23 @@ palmas {
 		....
 	};
 }
+
+Example: with interrupts extended
+ See Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+ Use pinmux 0x418 as wakeup interrupt and gpio1_0 as interrupt source
+
+palmas {
+	compatible = "ti,twl6035", "ti,palmas";
+	reg = <0x48>
+	interrupt-parent = <&intc>;
+	interrupt-controller;
+	#interrupt-cells = <2>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+	interrupts-extended = <&gpio1 0 IRQ_TYPE_LEVEL_HIGH
+			       &pinmux 0x418>;
+	pmic {
+		compatible = "ti,twl6035-pmic", "ti,palmas-pmic";
+		....
+	};
+}
diff --git a/drivers/mfd/palmas.c b/drivers/mfd/palmas.c
index 28cb048..11186ab 100644
--- a/drivers/mfd/palmas.c
+++ b/drivers/mfd/palmas.c
@@ -24,6 +24,7 @@
 #include <linux/mfd/core.h>
 #include <linux/mfd/palmas.h>
 #include <linux/of_device.h>
+#include <linux/of_irq.h>
 
 static const struct regmap_config palmas_regmap_config[PALMAS_NUM_CLIENTS] = {
 	{
@@ -326,6 +327,16 @@ static struct regmap_irq_chip tps65917_irq_chip = {
 			PALMAS_INT1_MASK),
 };
 
+static irqreturn_t palmas_wake_irq(int irq, void *_palmas)
+{
+	/*
+	 * Return Not handled so that interrupt is disabled.
+	 * Level event ensures that the event is eventually handled
+	 * by the appropriate chip handler already registered
+	 */
+	return IRQ_NONE;
+}
+
 int palmas_ext_control_req_config(struct palmas *palmas,
 	enum palmas_external_requestor_id id,  int ext_ctrl, bool enable)
 {
@@ -409,6 +420,7 @@ static void palmas_dt_to_pdata(struct i2c_client *i2c,
 		pdata->mux_from_pdata = 1;
 		pdata->pad2 = prop;
 	}
+	pdata->wakeirq = irq_of_parse_and_map(node, 1);
 
 	/* The default for this register is all masked */
 	ret = of_property_read_u32(node, "ti,power-ctrl", &prop);
@@ -521,6 +533,7 @@ static int palmas_i2c_probe(struct i2c_client *i2c,
 	i2c_set_clientdata(i2c, palmas);
 	palmas->dev = &i2c->dev;
 	palmas->irq = i2c->irq;
+	palmas->wakeirq = pdata->wakeirq;
 
 	match = of_match_device(of_palmas_match_tbl, &i2c->dev);
 
@@ -587,6 +600,22 @@ static int palmas_i2c_probe(struct i2c_client *i2c,
 	if (ret < 0)
 		goto err_i2c;
 
+	if (!palmas->wakeirq)
+		goto no_wake_irq;
+
+	ret = devm_request_irq(palmas->dev, palmas->wakeirq,
+			       palmas_wake_irq,
+			       IRQF_ONESHOT | pdata->irq_flags,
+			       dev_name(palmas->dev),
+			       &palmas);
+	if (ret < 0)
+		goto err_i2c;
+
+	/* We use wakeirq only during suspend-resume path */
+	device_set_wakeup_capable(palmas->dev, true);
+	disable_irq_nosync(palmas->wakeirq);
+
+no_wake_irq:
 no_irq:
 	slave = PALMAS_BASE_TO_SLAVE(PALMAS_PU_PD_OD_BASE);
 	addr = PALMAS_BASE_TO_REG(PALMAS_PU_PD_OD_BASE,
@@ -706,6 +735,34 @@ static int palmas_i2c_remove(struct i2c_client *i2c)
 	return 0;
 }
 
+static int palmas_i2c_suspend(struct i2c_client *i2c,  pm_message_t mesg)
+{
+	struct palmas *palmas = i2c_get_clientdata(i2c);
+	struct device *dev = &i2c->dev;
+
+	if (!palmas->wakeirq)
+		return 0;
+
+	if (device_may_wakeup(dev))
+		enable_irq(palmas->wakeirq);
+
+	return 0;
+}
+
+static int palmas_i2c_resume(struct i2c_client *i2c)
+{
+	struct palmas *palmas = i2c_get_clientdata(i2c);
+	struct device *dev = &i2c->dev;
+
+	if (!palmas->wakeirq)
+		return 0;
+
+	if (device_may_wakeup(dev))
+		disable_irq_nosync(palmas->wakeirq);
+
+	return 0;
+}
+
 static const struct i2c_device_id palmas_i2c_id[] = {
 	{ "palmas", },
 	{ "twl6035", },
@@ -721,6 +778,8 @@ static struct i2c_driver palmas_i2c_driver = {
 		   .of_match_table = of_palmas_match_tbl,
 		   .owner = THIS_MODULE,
 	},
+	.suspend = palmas_i2c_suspend,
+	.resume = palmas_i2c_resume,
 	.probe = palmas_i2c_probe,
 	.remove = palmas_i2c_remove,
 	.id_table = palmas_i2c_id,
diff --git a/include/linux/mfd/palmas.h b/include/linux/mfd/palmas.h
index fb0390a..e8cf4c2 100644
--- a/include/linux/mfd/palmas.h
+++ b/include/linux/mfd/palmas.h
@@ -75,6 +75,7 @@ struct palmas {
 	/* IRQ Data */
 	int irq;
 	u32 irq_mask;
+	int wakeirq;
 	struct mutex irq_lock;
 	struct regmap_irq_chip_data *irq_data;
 
@@ -377,6 +378,7 @@ struct palmas_clk_platform_data {
 
 struct palmas_platform_data {
 	int irq_flags;
+	int wakeirq;
 	int gpio_base;
 
 	/* bit value to be loaded to the POWER_CTRL register */
-- 
1.7.9.5