From aa9e90448e716a04badf6705ea58aeed9cf7429f Mon Sep 17 00:00:00 2001
From: "Ivan T. Ivanov" <ivan.ivanov@linaro.org>
Date: Fri, 18 Sep 2015 11:44:09 +0300
Subject: [PATCH] Input: pm8941: Add RESIN_N input handling

RESIN_N PMIC input is commonly used as "Volume Down"
button on Quallcom platforms. Add support for it.

TODO: Do it better.

Signed-off-by: Ivan T. Ivanov <ivan.ivanov@linaro.org>
---
 .../bindings/input/qcom,pm8941-pwrkey.txt     | 11 ++++
 drivers/input/misc/pm8941-pwrkey.c            | 64 +++++++++++++++++++
 2 files changed, 75 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/qcom,pm8941-pwrkey.txt b/Documentation/devicetree/bindings/input/qcom,pm8941-pwrkey.txt
index 07bf55f6e0b9..f3ae70b50b1e 100644
--- a/Documentation/devicetree/bindings/input/qcom,pm8941-pwrkey.txt
+++ b/Documentation/devicetree/bindings/input/qcom,pm8941-pwrkey.txt
@@ -32,6 +32,17 @@ PROPERTIES
 	Definition: presence of this property indicates that the KPDPWR_N pin
 		    should be configured for pull up.
 
+- resin-pull-up:
+	Usage: optional
+	Value type: <empty>
+	Definition: presence of this property indicates that the RESIN_N pin
+		    should be configured for pull up.
+
+- linux,code:
+	Usage: optional
+	Value type: <empty>
+	Definition: Keycode to emit when RESIN_N input change its state.
+
 EXAMPLE
 
 	pwrkey@800 {
diff --git a/drivers/input/misc/pm8941-pwrkey.c b/drivers/input/misc/pm8941-pwrkey.c
index e317b75357a0..7ba4fe1bfd3e 100644
--- a/drivers/input/misc/pm8941-pwrkey.c
+++ b/drivers/input/misc/pm8941-pwrkey.c
@@ -28,6 +28,7 @@
 
 #define PON_RT_STS			0x10
 #define  PON_KPDPWR_N_SET		BIT(0)
+#define  PON_RESIN_N_SET		BIT(1)
 
 #define PON_PS_HOLD_RST_CTL		0x5a
 #define PON_PS_HOLD_RST_CTL2		0x5b
@@ -37,6 +38,7 @@
 #define  PON_PS_HOLD_TYPE_HARD_RESET	7
 
 #define PON_PULL_CTL			0x70
+#define  PON_RESIN_PULL_UP		BIT(0)
 #define  PON_KPDPWR_PULL_UP		BIT(1)
 
 #define PON_DBC_CTL			0x71
@@ -52,6 +54,7 @@ struct pm8941_pwrkey {
 
 	unsigned int revision;
 	struct notifier_block reboot_notifier;
+	unsigned int resin_code;
 };
 
 static int pm8941_reboot_notify(struct notifier_block *nb,
@@ -130,6 +133,25 @@ static irqreturn_t pm8941_pwrkey_irq(int irq, void *_data)
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t pm8941_resin_irq(int irq, void *_data)
+{
+	struct pm8941_pwrkey *pwrkey = _data;
+	unsigned int sts;
+	int error;
+
+	error = regmap_read(pwrkey->regmap,
+			    pwrkey->baseaddr + PON_RT_STS, &sts);
+	if (error)
+		return IRQ_HANDLED;
+
+	input_report_key(pwrkey->input, pwrkey->resin_code,
+			 !!(sts & PON_RESIN_N_SET));
+
+	input_sync(pwrkey->input);
+
+	return IRQ_HANDLED;
+}
+
 static int __maybe_unused pm8941_pwrkey_suspend(struct device *dev)
 {
 	struct pm8941_pwrkey *pwrkey = dev_get_drvdata(dev);
@@ -153,6 +175,46 @@ static int __maybe_unused pm8941_pwrkey_resume(struct device *dev)
 static SIMPLE_DEV_PM_OPS(pm8941_pwr_key_pm_ops,
 			 pm8941_pwrkey_suspend, pm8941_pwrkey_resume);
 
+static void pm8941_resin_setup(struct platform_device *pdev,
+				struct pm8941_pwrkey *pwrkey)
+{
+	int irq, error;
+	bool pull_up;
+	u32 code;
+
+	irq = platform_get_irq(pdev, 1);
+	if (irq < 0)
+		return;
+
+	pull_up = of_property_read_bool(pdev->dev.of_node, "resin-pull-up");
+
+	error = regmap_update_bits(pwrkey->regmap,
+				   pwrkey->baseaddr + PON_PULL_CTL,
+				   PON_RESIN_PULL_UP,
+				   pull_up ? PON_RESIN_PULL_UP : 0);
+	if (error) {
+		dev_err(&pdev->dev, "failed to set pull: %d\n", error);
+		return;
+	}
+
+	error = of_property_read_u32(pdev->dev.of_node, "linux,code", &code);
+	if (error) {
+		dev_err(&pdev->dev, "resin no linux,code %d\n", error);
+		return;
+	}
+
+	pwrkey->resin_code = code;
+
+	input_set_capability(pwrkey->input, EV_KEY, code);
+
+	error = devm_request_threaded_irq(&pdev->dev, irq,
+					  NULL, pm8941_resin_irq,
+					  IRQF_ONESHOT,
+					  "pm8941_resin", pwrkey);
+	if (error)
+		dev_err(&pdev->dev, "failed requesting IRQ: %d\n", error);
+}
+
 static int pm8941_pwrkey_probe(struct platform_device *pdev)
 {
 	struct pm8941_pwrkey *pwrkey;
@@ -241,6 +303,8 @@ static int pm8941_pwrkey_probe(struct platform_device *pdev)
 		return error;
 	}
 
+	pm8941_resin_setup(pdev, pwrkey);
+
 	error = input_register_device(pwrkey->input);
 	if (error) {
 		dev_err(&pdev->dev, "failed to register input device: %d\n",
-- 
2.39.5