input: atc260x: Add onkey driver for ATC260x PMICs

The Actions Semi ATC260x PMICs are able to manage an onkey button.
This driver exposes the ATC260x onkey as an input device. It can also
be configured to force a system reset on a long key-press with an
adjustable duration.

The currently supported chip variants are ATC2603C and ATC2609A.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

3 files changed, 317 insertions, 1 deletions

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index ad1b6c90bc4d..7237dc440b98 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -94,6 +94,17 @@ config INPUT_ARIZONA_HAPTICS
 	  To compile this driver as a module, choose M here: the
 	  module will be called arizona-haptics.
 
+config INPUT_ATC260X_ONKEY
+	tristate "Actions Semi ATC260x PMIC ONKEY"
+	depends on MFD_ATC260X
+	help
+	  Support the ONKEY of ATC260x PMICs as an input device reporting
+	  power button status. ONKEY can be used to wakeup from low power
+	  modes and force a reset on long press.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called atc260x-onkey.
+
 config INPUT_ATMEL_CAPTOUCH
 	tristate "Atmel Capacitive Touch Button Driver"
 	depends on OF || COMPILE_TEST
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 7f202ba8f775..46db664a8bc4 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_INPUT_ADXL34X_SPI)		+= adxl34x-spi.o
 obj-$(CONFIG_INPUT_APANEL)		+= apanel.o
 obj-$(CONFIG_INPUT_ARIEL_PWRBUTTON)	+= ariel-pwrbutton.o
 obj-$(CONFIG_INPUT_ARIZONA_HAPTICS)	+= arizona-haptics.o
+obj-$(CONFIG_INPUT_ATC260X_ONKEY)	+= atc260x-onkey.o
 obj-$(CONFIG_INPUT_ATI_REMOTE2)		+= ati_remote2.o
 obj-$(CONFIG_INPUT_ATLAS_BTNS)		+= atlas_btns.o
 obj-$(CONFIG_INPUT_ATMEL_CAPTOUCH)	+= atmel_captouch.o
@@ -86,4 +87,3 @@ obj-$(CONFIG_INPUT_WM831X_ON)		+= wm831x-on.o
 obj-$(CONFIG_INPUT_XEN_KBDDEV_FRONTEND)	+= xen-kbdfront.o
 obj-$(CONFIG_INPUT_YEALINK)		+= yealink.o
 obj-$(CONFIG_INPUT_IDEAPAD_SLIDEBAR)	+= ideapad_slidebar.o
-
diff --git a/drivers/input/misc/atc260x-onkey.c b/drivers/input/misc/atc260x-onkey.c
new file mode 100644
index 000000000000..999aabf9dcbd
--- /dev/null
+++ b/drivers/input/misc/atc260x-onkey.c
@@ -0,0 +1,305 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Onkey driver for Actions Semi ATC260x PMICs.
+ *
+ * Copyright (c) 2020 Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/atc260x/core.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+/* <2s for short press, >2s for long press */
+#define KEY_PRESS_TIME_SEC	2
+
+/* Driver internals */
+enum atc260x_onkey_reset_status {
+	KEY_RESET_HW_DEFAULT,
+	KEY_RESET_DISABLED,
+	KEY_RESET_USER_SEL,
+};
+
+struct atc260x_onkey_params {
+	u32 reg_int_ctl;
+	u32 kdwn_state_bm;
+	u32 long_int_pnd_bm;
+	u32 short_int_pnd_bm;
+	u32 kdwn_int_pnd_bm;
+	u32 press_int_en_bm;
+	u32 kdwn_int_en_bm;
+	u32 press_time_bm;
+	u32 reset_en_bm;
+	u32 reset_time_bm;
+};
+
+struct atc260x_onkey {
+	struct atc260x *atc260x;
+	const struct atc260x_onkey_params *params;
+	struct input_dev *input_dev;
+	struct delayed_work work;
+	int irq;
+};
+
+static const struct atc260x_onkey_params atc2603c_onkey_params = {
+	.reg_int_ctl		= ATC2603C_PMU_SYS_CTL2,
+	.long_int_pnd_bm	= ATC2603C_PMU_SYS_CTL2_ONOFF_LONG_PRESS,
+	.short_int_pnd_bm	= ATC2603C_PMU_SYS_CTL2_ONOFF_SHORT_PRESS,
+	.kdwn_int_pnd_bm	= ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_PD,
+	.press_int_en_bm	= ATC2603C_PMU_SYS_CTL2_ONOFF_INT_EN,
+	.kdwn_int_en_bm		= ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_INT_EN,
+	.kdwn_state_bm		= ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS,
+	.press_time_bm		= ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_TIME,
+	.reset_en_bm		= ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_RESET_EN,
+	.reset_time_bm		= ATC2603C_PMU_SYS_CTL2_ONOFF_RESET_TIME_SEL,
+};
+
+static const struct atc260x_onkey_params atc2609a_onkey_params = {
+	.reg_int_ctl		= ATC2609A_PMU_SYS_CTL2,
+	.long_int_pnd_bm	= ATC2609A_PMU_SYS_CTL2_ONOFF_LONG_PRESS,
+	.short_int_pnd_bm	= ATC2609A_PMU_SYS_CTL2_ONOFF_SHORT_PRESS,
+	.kdwn_int_pnd_bm	= ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS_PD,
+	.press_int_en_bm	= ATC2609A_PMU_SYS_CTL2_ONOFF_LSP_INT_EN,
+	.kdwn_int_en_bm		= ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS_INT_EN,
+	.kdwn_state_bm		= ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS,
+	.press_time_bm		= ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS_TIME,
+	.reset_en_bm		= ATC2609A_PMU_SYS_CTL2_ONOFF_RESET_EN,
+	.reset_time_bm		= ATC2609A_PMU_SYS_CTL2_ONOFF_RESET_TIME_SEL,
+};
+
+static int atc2603x_onkey_hw_init(struct atc260x_onkey *onkey,
+				  enum atc260x_onkey_reset_status reset_status,
+				  u32 reset_time, u32 press_time)
+{
+	u32 reg_bm, reg_val;
+
+	reg_bm = onkey->params->long_int_pnd_bm |
+		 onkey->params->short_int_pnd_bm |
+		 onkey->params->kdwn_int_pnd_bm |
+		 onkey->params->press_int_en_bm |
+		 onkey->params->kdwn_int_en_bm;
+
+	reg_val = reg_bm | press_time;
+	reg_bm |= onkey->params->press_time_bm;
+
+	if (reset_status == KEY_RESET_DISABLED) {
+		reg_bm |= onkey->params->reset_en_bm;
+	} else if (reset_status == KEY_RESET_USER_SEL) {
+		reg_bm |= onkey->params->reset_en_bm |
+			  onkey->params->reset_time_bm;
+		reg_val |= onkey->params->reset_en_bm | reset_time;
+	}
+
+	return regmap_update_bits(onkey->atc260x->regmap,
+				  onkey->params->reg_int_ctl, reg_bm, reg_val);
+}
+
+static void atc260x_onkey_query(struct atc260x_onkey *onkey)
+{
+	u32 reg_bits;
+	int ret, key_down;
+
+	ret = regmap_read(onkey->atc260x->regmap,
+			  onkey->params->reg_int_ctl, &key_down);
+	if (ret) {
+		key_down = 1;
+		dev_err(onkey->atc260x->dev,
+			"Failed to read onkey status: %d\n", ret);
+	} else {
+		key_down &= onkey->params->kdwn_state_bm;
+	}
+
+	/*
+	 * The hardware generates interrupt only when the onkey pin is
+	 * asserted. Hence, the deassertion of the pin is simulated through
+	 * work queue.
+	 */
+	if (key_down) {
+		schedule_delayed_work(&onkey->work, msecs_to_jiffies(200));
+		return;
+	}
+
+	/*
+	 * The key-down status bit is cleared when the On/Off button
+	 * is released.
+	 */
+	input_report_key(onkey->input_dev, KEY_POWER, 0);
+	input_sync(onkey->input_dev);
+
+	reg_bits = onkey->params->long_int_pnd_bm |
+		   onkey->params->short_int_pnd_bm |
+		   onkey->params->kdwn_int_pnd_bm |
+		   onkey->params->press_int_en_bm |
+		   onkey->params->kdwn_int_en_bm;
+
+	/* Clear key press pending events and enable key press interrupts. */
+	regmap_update_bits(onkey->atc260x->regmap, onkey->params->reg_int_ctl,
+			   reg_bits, reg_bits);
+}
+
+static void atc260x_onkey_work(struct work_struct *work)
+{
+	struct atc260x_onkey *onkey = container_of(work, struct atc260x_onkey,
+						   work.work);
+	atc260x_onkey_query(onkey);
+}
+
+static irqreturn_t atc260x_onkey_irq(int irq, void *data)
+{
+	struct atc260x_onkey *onkey = data;
+	int ret;
+
+	/* Disable key press interrupts. */
+	ret = regmap_update_bits(onkey->atc260x->regmap,
+				 onkey->params->reg_int_ctl,
+				 onkey->params->press_int_en_bm |
+				 onkey->params->kdwn_int_en_bm, 0);
+	if (ret)
+		dev_err(onkey->atc260x->dev,
+			"Failed to disable interrupts: %d\n", ret);
+
+	input_report_key(onkey->input_dev, KEY_POWER, 1);
+	input_sync(onkey->input_dev);
+
+	atc260x_onkey_query(onkey);
+
+	return IRQ_HANDLED;
+}
+
+static int atc260x_onkey_open(struct input_dev *dev)
+{
+	struct atc260x_onkey *onkey = input_get_drvdata(dev);
+
+	enable_irq(onkey->irq);
+
+	return 0;
+}
+
+static void atc260x_onkey_close(struct input_dev *dev)
+{
+	struct atc260x_onkey *onkey = input_get_drvdata(dev);
+
+	disable_irq(onkey->irq);
+	cancel_delayed_work_sync(&onkey->work);
+}
+
+static int atc260x_onkey_probe(struct platform_device *pdev)
+{
+	struct atc260x *atc260x = dev_get_drvdata(pdev->dev.parent);
+	struct atc260x_onkey *onkey;
+	struct input_dev *input_dev;
+	enum atc260x_onkey_reset_status reset_status;
+	u32 press_time = KEY_PRESS_TIME_SEC, reset_time = 0;
+	int val, error;
+
+	onkey = devm_kzalloc(&pdev->dev, sizeof(*onkey), GFP_KERNEL);
+	if (!onkey)
+		return -ENOMEM;
+
+	error = device_property_read_u32(pdev->dev.parent,
+					 "reset-time-sec", &val);
+	if (error) {
+		reset_status = KEY_RESET_HW_DEFAULT;
+	} else if (val) {
+		if (val < 6 || val > 12) {
+			dev_err(&pdev->dev, "reset-time-sec out of range\n");
+			return -EINVAL;
+		}
+
+		reset_status = KEY_RESET_USER_SEL;
+		reset_time = (val - 6) / 2;
+	} else {
+		reset_status = KEY_RESET_DISABLED;
+		dev_dbg(&pdev->dev, "Disabled reset on long-press\n");
+	}
+
+	switch (atc260x->ic_type) {
+	case ATC2603C:
+		onkey->params = &atc2603c_onkey_params;
+		press_time = FIELD_PREP(ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_TIME,
+					press_time);
+		reset_time = FIELD_PREP(ATC2603C_PMU_SYS_CTL2_ONOFF_RESET_TIME_SEL,
+					reset_time);
+		break;
+	case ATC2609A:
+		onkey->params = &atc2609a_onkey_params;
+		press_time = FIELD_PREP(ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS_TIME,
+					press_time);
+		reset_time = FIELD_PREP(ATC2609A_PMU_SYS_CTL2_ONOFF_RESET_TIME_SEL,
+					reset_time);
+		break;
+	default:
+		dev_err(&pdev->dev,
+			"OnKey not supported for ATC260x PMIC type: %u\n",
+			atc260x->ic_type);
+		return -EINVAL;
+	}
+
+	input_dev = devm_input_allocate_device(&pdev->dev);
+	if (!input_dev) {
+		dev_err(&pdev->dev, "Failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	onkey->input_dev = input_dev;
+	onkey->atc260x = atc260x;
+
+	input_dev->name = "atc260x-onkey";
+	input_dev->phys = "atc260x-onkey/input0";
+	input_dev->open = atc260x_onkey_open;
+	input_dev->close = atc260x_onkey_close;
+
+	input_set_capability(input_dev, EV_KEY, KEY_POWER);
+	input_set_drvdata(input_dev, onkey);
+
+	INIT_DELAYED_WORK(&onkey->work, atc260x_onkey_work);
+
+	onkey->irq = platform_get_irq(pdev, 0);
+	if (onkey->irq < 0)
+		return onkey->irq;
+
+	error = devm_request_threaded_irq(&pdev->dev, onkey->irq, NULL,
+					  atc260x_onkey_irq, IRQF_ONESHOT,
+					  dev_name(&pdev->dev), onkey);
+	if (error) {
+		dev_err(&pdev->dev,
+			"Failed to register IRQ %d: %d\n", onkey->irq, error);
+		return error;
+	}
+
+	/* Keep IRQ disabled until atc260x_onkey_open() is called. */
+	disable_irq(onkey->irq);
+
+	error = input_register_device(input_dev);
+	if (error) {
+		dev_err(&pdev->dev,
+			"Failed to register input device: %d\n", error);
+		return error;
+	}
+
+	error = atc2603x_onkey_hw_init(onkey, reset_status,
+				       reset_time, press_time);
+	if (error)
+		return error;
+
+	device_init_wakeup(&pdev->dev, true);
+
+	return 0;
+}
+
+static struct platform_driver atc260x_onkey_driver = {
+	.probe	= atc260x_onkey_probe,
+	.driver	= {
+		.name = "atc260x-onkey",
+	},
+};
+
+module_platform_driver(atc260x_onkey_driver);
+
+MODULE_DESCRIPTION("Onkey driver for ATC260x PMICs");
+MODULE_AUTHOR("Cristian Ciocaltea <cristian.ciocaltea@gmail.com>");
+MODULE_LICENSE("GPL");