[PATCH v2 0/4] input: Add new sun4i-lradc-keys driver

[PATCH v2 0/4] input: Add new sun4i-lradc-keys driver

[Hans de Goede]

Hi Dimitri et al,

Here is v2 of the sun4i-lradc-keys driver, changes since v1:

- Use include/dt-bindings/input/input.h
- Rename the keycodes property to linux,chan0-keycodes

Regards,

Hans

[PATCH v2 1/4] input: Add new sun4i-lradc-keys driver

[Hans de Goede]

Allwinnner sunxi SoCs have a low resolution adc (called lradc) which is
specifically designed to have various (tablet) keys (ie home, back, search,
etc). attached to it using a resistor network. This adds a driver for this.

There are 2 channels, currently this driver only supports chan0 since there
are no boards known to use chan1. The devicetree properties are already
prefixed with chan0 as preparation for chan1 support in the future.

This has been tested on an olimex a10s-olinuxino-micro, a13-olinuxino, and
a20-olinuxino-micro.

Signed-off-by: Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 .../devicetree/bindings/input/sun4i-lradc-keys.txt |  22 ++
 drivers/input/keyboard/Kconfig                     |  10 +
 drivers/input/keyboard/Makefile                    |   1 +
 drivers/input/keyboard/sun4i-lradc-keys.c          | 243 +++++++++++++++++++++
 4 files changed, 276 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
 create mode 100644 drivers/input/keyboard/sun4i-lradc-keys.c

diff --git a/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt b/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
new file mode 100644
index 0000000..7801264
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
@@ -0,0 +1,22 @@
+Allwinner sun4i low res adc attached tablet keys
+------------------------------------------------
+
+Required properties:
+ - compatible: "allwinner,sun4i-lradc-keys"
+ - reg: mmio address range of the chip
+ - interrupts: interrupt to which the chip is connected
+ - allwinner,chan0-step: step in mV between keys must be 150 or 200
+ - linux,chan0-keycodes: array of dt-bindings/input/input.h KEY_ codes
+
+Example:
+
+#include <dt-bindings/input/input.h>
+
+	lradc: lradc@01c22800 {
+		compatible = "allwinner,sun4i-lradc-keys";
+		reg = <0x01c22800 0x100>;
+		interrupts = <31>;
+		allwinner,chan0-step = <200>;
+		linux,chan0-keycodes = <KEY_VOLUMEUP KEY_VOLUMEDOWN
+					KEY_MENU KEY_ENTER KEY_HOME>;
+	};
diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index bb174c1..d95e6e4 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -544,6 +544,16 @@ config KEYBOARD_STMPE
 	  To compile this driver as a module, choose M here: the module will be
 	  called stmpe-keypad.
 
+config KEYBOARD_SUN4I_LRADC
+	tristate "Allwinner sun4i low res adc attached tablet keys support"
+	depends on ARCH_SUNXI
+	help
+	  This selects support for the Allwinner low res adc attached tablet
+	  keys found on Allwinner sunxi SoCs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called sun4i-lradc-keys.
+
 config KEYBOARD_DAVINCI
 	tristate "TI DaVinci Key Scan"
 	depends on ARCH_DAVINCI_DM365
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index a699b61..f3265bd 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_KEYBOARD_SH_KEYSC)		+= sh_keysc.o
 obj-$(CONFIG_KEYBOARD_SPEAR)		+= spear-keyboard.o
 obj-$(CONFIG_KEYBOARD_STMPE)		+= stmpe-keypad.o
 obj-$(CONFIG_KEYBOARD_STOWAWAY)		+= stowaway.o
+obj-$(CONFIG_KEYBOARD_SUN4I_LRADC)	+= sun4i-lradc-keys.o
 obj-$(CONFIG_KEYBOARD_SUNKBD)		+= sunkbd.o
 obj-$(CONFIG_KEYBOARD_TC3589X)		+= tc3589x-keypad.o
 obj-$(CONFIG_KEYBOARD_TEGRA)		+= tegra-kbc.o
diff --git a/drivers/input/keyboard/sun4i-lradc-keys.c b/drivers/input/keyboard/sun4i-lradc-keys.c
new file mode 100644
index 0000000..5c55e17
--- /dev/null
+++ b/drivers/input/keyboard/sun4i-lradc-keys.c
@@ -0,0 +1,243 @@
+/*
+ * Allwinner sun4i low res adc attached tablet keys driver
+ *
+ * Copyright (C) 2014 Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * Allwinnner sunxi SoCs have a lradc which is specifically designed to have
+ * various (tablet) keys (ie home, back, search, etc). attached to it using
+ * a resistor network. This driver is for the keys on such boards.
+ *
+ * There are 2 channels, currently this driver only supports chan0 since there
+ * are no boards known to use chan1. The devicetree properties are already
+ * prefixed with chan0 as preparation for chan1 support in the future.
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define LRADC_CTRL		0x00
+#define LRADC_INTC		0x04
+#define LRADC_INTS		0x08
+#define LRADC_DATA0		0x0c
+#define LRADC_DATA1		0x10
+
+/* LRADC_CTRL bits */
+#define FIRST_CONVERT_DLY(x)	((x) << 24) /* 8 bits */
+#define CHAN_SELECT(x)		((x) << 22) /* 2 bits */
+#define CONTINUE_TIME_SEL(x)	((x) << 16) /* 4 bits */
+#define KEY_MODE_SEL(x)		((x) << 12) /* 2 bits */
+#define LEVELA_B_CNT(x)		((x) << 8)  /* 4 bits */
+#define HOLD_EN(x)		((x) << 6)
+#define LEVELB_VOL(x)		((x) << 4)  /* 2 bits */
+#define SAMPLE_RATE(x)		((x) << 2)  /* 2 bits */
+#define ENABLE(x)		((x) << 0)
+
+/* LRADC_INTC and LRADC_INTS bits */
+#define CHAN1_KEYUP_IRQ		BIT(12)
+#define CHAN1_ALRDY_HOLD_IRQ	BIT(11)
+#define CHAN1_HOLD_IRQ		BIT(10)
+#define	CHAN1_KEYDOWN_IRQ	BIT(9)
+#define CHAN1_DATA_IRQ		BIT(8)
+#define CHAN0_KEYUP_IRQ		BIT(4)
+#define CHAN0_ALRDY_HOLD_IRQ	BIT(3)
+#define CHAN0_HOLD_IRQ		BIT(2)
+#define	CHAN0_KEYDOWN_IRQ	BIT(1)
+#define CHAN0_DATA_IRQ		BIT(0)
+
+#define MAX_KEYS		13
+
+/* Lookup table to map the adc val to a keycode index for 150 mv step size */
+static const u8 adc_val_to_key_index_step150[64] = {
+	0, 0, 0,
+	1, 1, 1, 1, 1,
+	2, 2, 2, 2, 2,
+	3, 3, 3, 3,
+	4, 4, 4, 4, 4,
+	5, 5, 5, 5, 5,
+	6, 6, 6, 6, 6,
+	7, 7, 7, 7,
+	8, 8, 8, 8, 8,
+	9, 9, 9, 9, 9,
+	10, 10, 10, 10,
+	11, 11, 11, 11,
+	12, 12, 12, 12, 12, 12, 12, 12, 12, 12
+};
+
+/* Lookup table to map the adc val to a keycode index for 200 mv step size */
+static const u8 adc_val_to_key_index_step200[64] = {
+	0, 0, 0, 0, 0, 0, 0, 0,
+	1, 1, 1, 1, 1, 1, 1,
+	2, 2, 2, 2, 2, 2, 2,
+	3, 3, 3, 3, 3, 3,
+	4, 4, 4, 4, 4, 4,
+	5, 5, 5, 5, 5, 5,
+	6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
+};
+
+struct sun4i_lradc_data {
+	struct device *dev;
+	struct input_dev *input;
+	void __iomem *base;
+	u32 chan0_step;
+	u32 chan0_keycode;
+	u32 chan0_keycodes[MAX_KEYS];
+};
+
+static irqreturn_t sun4i_lradc_irq(int irq, void *dev_id)
+{
+	struct sun4i_lradc_data *lradc = dev_id;
+	u32 ints, val;
+
+	ints  = readl(lradc->base + LRADC_INTS);
+
+	/*
+	 * lradc supports only one keypress at a time, release does not give
+	 * any info as to which key was released, so we cache the keycode.
+	 */
+	if ((ints & CHAN0_KEYDOWN_IRQ) && lradc->chan0_keycode == 0) {
+		val = readl(lradc->base + LRADC_DATA0);
+		if (lradc->chan0_step == 150)
+			val = adc_val_to_key_index_step150[val];
+		else
+			val = adc_val_to_key_index_step200[val];
+
+		lradc->chan0_keycode = lradc->chan0_keycodes[val];
+		input_report_key(lradc->input, lradc->chan0_keycode, 1);
+	}
+
+	if (ints & CHAN0_KEYUP_IRQ) {
+		input_report_key(lradc->input, lradc->chan0_keycode, 0);
+		lradc->chan0_keycode = 0;
+	}
+
+	input_sync(lradc->input);
+
+	writel(ints, lradc->base + LRADC_INTS);
+
+	return IRQ_HANDLED;
+}
+
+static int sun4i_lradc_open(struct input_dev *dev)
+{
+	struct sun4i_lradc_data *lradc = input_get_drvdata(dev);
+
+	/*
+	 * Set sample time to 16 ms / 62.5 Hz. Wait 2 * 16 ms for key to
+	 * stabilize on press, wait (1 + 1) * 16 ms for key release
+	 */
+	writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) |
+		SAMPLE_RATE(2) | ENABLE(1), lradc->base + LRADC_CTRL);
+
+	writel(CHAN0_KEYUP_IRQ | CHAN0_KEYDOWN_IRQ, lradc->base + LRADC_INTC);
+
+	return 0;
+}
+
+static void sun4i_lradc_close(struct input_dev *dev)
+{
+	struct sun4i_lradc_data *lradc = input_get_drvdata(dev);
+
+	/* Disable lradc, leave other settings unchanged */
+	writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) |
+		SAMPLE_RATE(2), lradc->base + LRADC_CTRL);
+	writel(0, lradc->base + LRADC_INTC);
+}
+
+static int sun4i_lradc_probe(struct platform_device *pdev)
+{
+	struct sun4i_lradc_data *lradc;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	int i, ret;
+
+	lradc = devm_kzalloc(dev, sizeof(struct sun4i_lradc_data), GFP_KERNEL);
+	if (!lradc)
+		return -ENOMEM;
+
+	ret = of_property_read_u32(np, "allwinner,chan0-step",
+				   &lradc->chan0_step);
+	if (ret || (lradc->chan0_step != 150 && lradc->chan0_step != 200)) {
+		dev_err(dev, "Invalid allwinner,chan0-step dt-property\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < MAX_KEYS; i++)
+		of_property_read_u32_index(np, "linux,chan0-keycodes",
+					   i, &lradc->chan0_keycodes[i]);
+
+	lradc->dev = dev;
+	lradc->input = devm_input_allocate_device(dev);
+	if (!lradc->input)
+		return -ENOMEM;
+
+	lradc->input->name = pdev->name;
+	lradc->input->phys = "sun4i_lradc/input0";
+	lradc->input->open = sun4i_lradc_open;
+	lradc->input->close = sun4i_lradc_close;
+	lradc->input->id.bustype = BUS_HOST;
+	lradc->input->id.vendor = 0x0001;
+	lradc->input->id.product = 0x0001;
+	lradc->input->id.version = 0x0100;
+	lradc->input->evbit[0] =  BIT(EV_SYN) | BIT(EV_KEY);
+	for (i = 0; i < MAX_KEYS; i++)
+		set_bit(lradc->chan0_keycodes[i], lradc->input->keybit);
+	input_set_drvdata(lradc->input, lradc);
+
+	lradc->base = devm_ioremap_resource(dev,
+			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
+	if (IS_ERR(lradc->base))
+		return PTR_ERR(lradc->base);
+
+	ret = devm_request_irq(dev, platform_get_irq(pdev, 0), sun4i_lradc_irq,
+			       0, "sun4i-lradc-keys", lradc);
+	if (ret)
+		return ret;
+
+	ret = input_register_device(lradc->input);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, lradc);
+	return 0;
+}
+
+static const struct of_device_id sun4i_lradc_of_match[] = {
+	{ .compatible = "allwinner,sun4i-lradc-keys", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sun4i_lradc_of_match);
+
+static struct platform_driver sun4i_lradc_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= "sun4i-lradc-keys",
+		.of_match_table = of_match_ptr(sun4i_lradc_of_match),
+	},
+	.probe	= sun4i_lradc_probe,
+};
+
+module_platform_driver(sun4i_lradc_driver);
+
+MODULE_DESCRIPTION("Allwinner sun4i low res adc attached tablet keys driver");
+MODULE_AUTHOR("Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>");
+MODULE_LICENSE("GPL");
-- 
1.8.4.2

[PATCH v2 2/4] ARM: dts: sun4i: Add lradc node

[Hans de Goede]

Signed-off-by: Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 arch/arm/boot/dts/sun4i-a10.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/boot/dts/sun4i-a10.dtsi b/arch/arm/boot/dts/sun4i-a10.dtsi
index 502f3e2..88f119a 100644
--- a/arch/arm/boot/dts/sun4i-a10.dtsi
+++ b/arch/arm/boot/dts/sun4i-a10.dtsi
@@ -447,6 +447,13 @@
 			interrupts = <24>;
 		};
 
+		lradc: lradc@01c22800 {
+			compatible = "allwinner,sun4i-lradc-keys";
+			reg = <0x01c22800 0x100>;
+			interrupts = <31>;
+			status = "disabled";
+		};
+
 		sid: eeprom@01c23800 {
 			compatible = "allwinner,sun4i-sid";
 			reg = <0x01c23800 0x10>;
-- 
1.8.4.2

[PATCH v2 3/4] ARM: dts: sun5i: Add lradc node

[Hans de Goede]

Signed-off-by: Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 arch/arm/boot/dts/sun5i-a10s-olinuxino-micro.dts | 8 ++++++++
 arch/arm/boot/dts/sun5i-a10s.dtsi                | 7 +++++++
 arch/arm/boot/dts/sun5i-a13-olinuxino.dts        | 8 ++++++++
 arch/arm/boot/dts/sun5i-a13.dtsi                 | 7 +++++++
 4 files changed, 30 insertions(+)

diff --git a/arch/arm/boot/dts/sun5i-a10s-olinuxino-micro.dts b/arch/arm/boot/dts/sun5i-a10s-olinuxino-micro.dts
index e53fb12..d93318a 100644
--- a/arch/arm/boot/dts/sun5i-a10s-olinuxino-micro.dts
+++ b/arch/arm/boot/dts/sun5i-a10s-olinuxino-micro.dts
@@ -13,6 +13,7 @@
 
 /dts-v1/;
 /include/ "sun5i-a10s.dtsi"
+#include <dt-bindings/input/input.h>
 
 / {
 	model = "Olimex A10s-Olinuxino Micro";
@@ -75,6 +76,13 @@
 			};
 		};
 
+		lradc: lradc@01c22800 {
+			allwinner,chan0-step = <200>;
+			linux,chan0-keycodes = <KEY_VOLUMEUP KEY_VOLUMEDOWN
+						KEY_MENU KEY_ENTER KEY_HOME>;
+			status = "okay";
+		};
+
 		uart0: serial@01c28000 {
 			pinctrl-names = "default";
 			pinctrl-0 = <&uart0_pins_a>;
diff --git a/arch/arm/boot/dts/sun5i-a10s.dtsi b/arch/arm/boot/dts/sun5i-a10s.dtsi
index 34dd303..8775bad 100644
--- a/arch/arm/boot/dts/sun5i-a10s.dtsi
+++ b/arch/arm/boot/dts/sun5i-a10s.dtsi
@@ -404,6 +404,13 @@
 			reg = <0x01c20c90 0x10>;
 		};
 
+		lradc: lradc@01c22800 {
+			compatible = "allwinner,sun4i-lradc-keys";
+			reg = <0x01c22800 0x100>;
+			interrupts = <31>;
+			status = "disabled";
+		};
+
 		sid: eeprom@01c23800 {
 			compatible = "allwinner,sun4i-sid";
 			reg = <0x01c23800 0x10>;
diff --git a/arch/arm/boot/dts/sun5i-a13-olinuxino.dts b/arch/arm/boot/dts/sun5i-a13-olinuxino.dts
index ab566f7..4e99f43 100644
--- a/arch/arm/boot/dts/sun5i-a13-olinuxino.dts
+++ b/arch/arm/boot/dts/sun5i-a13-olinuxino.dts
@@ -13,6 +13,7 @@
 
 /dts-v1/;
 /include/ "sun5i-a13.dtsi"
+#include <dt-bindings/input/input.h>
 
 / {
 	model = "Olimex A13-Olinuxino";
@@ -55,6 +56,13 @@
 			};
 		};
 
+		lradc: lradc@01c22800 {
+			allwinner,chan0-step = <200>;
+			linux,chan0-keycodes = <KEY_VOLUMEUP KEY_VOLUMEDOWN
+						KEY_MENU KEY_ENTER KEY_HOME>;
+			status = "okay";
+		};
+
 		uart1: serial@01c28400 {
 			pinctrl-names = "default";
 			pinctrl-0 = <&uart1_pins_b>;
diff --git a/arch/arm/boot/dts/sun5i-a13.dtsi b/arch/arm/boot/dts/sun5i-a13.dtsi
index 264cfa4..90c1ed3 100644
--- a/arch/arm/boot/dts/sun5i-a13.dtsi
+++ b/arch/arm/boot/dts/sun5i-a13.dtsi
@@ -362,6 +362,13 @@
 			reg = <0x01c20c90 0x10>;
 		};
 
+		lradc: lradc@01c22800 {
+			compatible = "allwinner,sun4i-lradc-keys";
+			reg = <0x01c22800 0x100>;
+			interrupts = <31>;
+			status = "disabled";
+		};
+
 		sid: eeprom@01c23800 {
 			compatible = "allwinner,sun4i-sid";
 			reg = <0x01c23800 0x10>;
-- 
1.8.4.2

[PATCH v2 4/4] ARM: dts: sun7i: Add lradc node

[Hans de Goede]

Signed-off-by: Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 arch/arm/boot/dts/sun7i-a20-olinuxino-micro.dts | 9 +++++++++
 arch/arm/boot/dts/sun7i-a20.dtsi                | 7 +++++++
 2 files changed, 16 insertions(+)

diff --git a/arch/arm/boot/dts/sun7i-a20-olinuxino-micro.dts b/arch/arm/boot/dts/sun7i-a20-olinuxino-micro.dts
index 0ee2641..2c9a38f 100644
--- a/arch/arm/boot/dts/sun7i-a20-olinuxino-micro.dts
+++ b/arch/arm/boot/dts/sun7i-a20-olinuxino-micro.dts
@@ -13,6 +13,7 @@
 
 /dts-v1/;
 /include/ "sun7i-a20.dtsi"
+#include <dt-bindings/input/input.h>
 
 / {
 	model = "Olimex A20-Olinuxino Micro";
@@ -86,6 +87,14 @@
 			};
 		};
 
+		lradc: lradc@01c22800 {
+			allwinner,chan0-step = <200>;
+			linux,chan0-keycodes = <KEY_VOLUMEUP KEY_VOLUMEDOWN
+						KEY_MENU KEY_SEARCH KEY_HOME
+						KEY_ESC KEY_ENTER>;
+			status = "okay";
+		};
+
 		uart0: serial@01c28000 {
 			pinctrl-names = "default";
 			pinctrl-0 = <&uart0_pins_a>;
diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi
index 68e825a..3484275 100644
--- a/arch/arm/boot/dts/sun7i-a20.dtsi
+++ b/arch/arm/boot/dts/sun7i-a20.dtsi
@@ -531,6 +531,13 @@
 			interrupts = <0 24 1>;
 		};
 
+		lradc: lradc@01c22800 {
+			compatible = "allwinner,sun4i-lradc-keys";
+			reg = <0x01c22800 0x100>;
+			interrupts = <0 31 4>;
+			status = "disabled";
+		};
+
 		sid: eeprom@01c23800 {
 			compatible = "allwinner,sun7i-a20-sid";
 			reg = <0x01c23800 0x200>;
-- 
1.8.4.2

Re: [PATCH v2 0/4] input: Add new sun4i-lradc-keys driver

[Chen-Yu Tsai]

Hi Hans,

It seems this series didn't get any attention. Care to respin on top
of the latest tree?

FYI, I have the series rebased on top of sunxi-next:
https://github.com/wens/linux/commits/others/sunxi-lradc-input-v2

ChenYu

On Thu, Jan 2, 2014 at 5:58 PM, Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:
> Hi Dimitri et al,
>
> Here is v2 of the sun4i-lradc-keys driver, changes since v1:
>
> - Use include/dt-bindings/input/input.h
> - Rename the keycodes property to linux,chan0-keycodes
>
> Regards,
>
> Hans
>
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Re: [PATCH v2 0/4] input: Add new sun4i-lradc-keys driver

[Hans de Goede]

Hi,

On 09/01/2014 03:47 PM, Chen-Yu Tsai wrote:
> Hi Hans,
> 
> It seems this series didn't get any attention. Care to respin on top
> of the latest tree?
> 
> FYI, I have the series rebased on top of sunxi-next:
> https://github.com/wens/linux/commits/others/sunxi-lradc-input-v2

The problem is not it not getting attention, the problem is people were
unhappy with the dt-bindings for this. I've a pretty good idea of how
to fix up the bindings, but -ENOTIME so far. If you've a board you can
test this on and want to take a shot at fixing it up, I can get into
a little bit more detail.

Regards,

Hans

[PATCH v2 1/4] input: Add new sun4i-lradc-keys driver

[Hans de Goede]

Allwinnner sunxi SoCs have a low resolution adc (called lradc) which is
specifically designed to have various (tablet) keys (ie home, back, search,
etc). attached to it using a resistor network. This adds a driver for this.

There are 2 channels, currently this driver only supports chan0 since there
are no boards known to use chan1.

This has been tested on an olimex a10s-olinuxino-micro, a13-olinuxino, and
a20-olinuxino-micro.

Signed-off-by: Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
--
Changes in v2:
-Change devicetree bindings to use a per key subnode, like gpio-keys does
---
 .../devicetree/bindings/input/sun4i-lradc-keys.txt |  57 +++++
 MAINTAINERS                                        |   7 +
 drivers/input/keyboard/Kconfig                     |  10 +
 drivers/input/keyboard/Makefile                    |   1 +
 drivers/input/keyboard/sun4i-lradc-keys.c          | 259 +++++++++++++++++++++
 5 files changed, 334 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
 create mode 100644 drivers/input/keyboard/sun4i-lradc-keys.c

diff --git a/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt b/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
new file mode 100644
index 0000000..36a141b
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
@@ -0,0 +1,57 @@
+Allwinner sun4i low res adc attached tablet keys
+------------------------------------------------
+
+Required properties:
+ - compatible: "allwinner,sun4i-lradc-keys"
+ - reg: mmio address range of the chip
+ - interrupts: interrupt to which the chip is connected
+ - vref-supply: powersupply for the lradc reference voltage
+
+Each key is represented as a sub-node of "allwinner,sun4i-lradc-keys":
+
+Required subnode-properties:
+	- label: Descriptive name of the key.
+	- linux,code: Keycode to emit.
+	- channel: Channel this key is attached to, mut be 0 or 1.
+	- voltage: Voltage in µV at lradc input when this key is pressed.
+
+Example:
+
+#include <dt-bindings/input/input.h>
+
+	lradc: lradc@01c22800 {
+		compatible = "allwinner,sun4i-lradc-keys";
+		reg = <0x01c22800 0x100>;
+		interrupts = <31>;
+		vref-supply = <&reg_vcc3v0>;
+		button@19 {
+			label = "Volume Up";
+			linux,code = <KEY_VOLUMEUP>;
+			channel = <0>;
+			voltage = <191274>;
+		};
+		button@39 {
+			label = "Volume Down";
+			linux,code = <KEY_VOLUMEDOWN>;
+			channel = <0>;
+			voltage = <392644>;
+		};
+		button@60 {
+			label = "Menu";
+			linux,code = <KEY_MENU>;
+			channel = <0>;
+			voltage = <601151>;
+		};
+		button@80 {
+			label = "Enter";
+			linux,code = <KEY_ENTER>;
+			channel = <0>;
+			voltage = <795090>;
+		};
+		button@98 {
+			label = "Home";
+			linux,code = <KEY_HOME>;
+			channel = <0>;
+			voltage = <987387>;
+		};
+	};
diff --git a/MAINTAINERS b/MAINTAINERS
index a20df9b..73d1aef 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8932,6 +8932,13 @@ F:	arch/m68k/sun3*/
 F:	arch/m68k/include/asm/sun3*
 F:	drivers/net/ethernet/i825xx/sun3*
 
+SUN4I LOW RES ADC ATTACHED TABLET KEYS DRIVER
+M:	Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
+L:	linux-input-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
+F:	drivers/input/keyboard/sun4i-lradc-keys.c
+
 SUNDANCE NETWORK DRIVER
 M:	Denis Kirjanov <kda-u1c8ncikuMvVAZt0uhVF+Ni2O/JbrIOy@public.gmane.org>
 L:	netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index a3958c6..2d11b44 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -567,6 +567,16 @@ config KEYBOARD_STMPE
 	  To compile this driver as a module, choose M here: the module will be
 	  called stmpe-keypad.
 
+config KEYBOARD_SUN4I_LRADC
+	tristate "Allwinner sun4i low res adc attached tablet keys support"
+	depends on ARCH_SUNXI
+	help
+	  This selects support for the Allwinner low res adc attached tablet
+	  keys found on Allwinner sunxi SoCs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called sun4i-lradc-keys.
+
 config KEYBOARD_DAVINCI
 	tristate "TI DaVinci Key Scan"
 	depends on ARCH_DAVINCI_DM365
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index 0a33456..a35269a 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_KEYBOARD_SPEAR)		+= spear-keyboard.o
 obj-$(CONFIG_KEYBOARD_STMPE)		+= stmpe-keypad.o
 obj-$(CONFIG_KEYBOARD_STOWAWAY)		+= stowaway.o
 obj-$(CONFIG_KEYBOARD_ST_KEYSCAN)	+= st-keyscan.o
+obj-$(CONFIG_KEYBOARD_SUN4I_LRADC)	+= sun4i-lradc-keys.o
 obj-$(CONFIG_KEYBOARD_SUNKBD)		+= sunkbd.o
 obj-$(CONFIG_KEYBOARD_TC3589X)		+= tc3589x-keypad.o
 obj-$(CONFIG_KEYBOARD_TEGRA)		+= tegra-kbc.o
diff --git a/drivers/input/keyboard/sun4i-lradc-keys.c b/drivers/input/keyboard/sun4i-lradc-keys.c
new file mode 100644
index 0000000..63a1aff
--- /dev/null
+++ b/drivers/input/keyboard/sun4i-lradc-keys.c
@@ -0,0 +1,259 @@
+/*
+ * Allwinner sun4i low res adc attached tablet keys driver
+ *
+ * Copyright (C) 2014 Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * Allwinnner sunxi SoCs have a lradc which is specifically designed to have
+ * various (tablet) keys (ie home, back, search, etc). attached to it using
+ * a resistor network. This driver is for the keys on such boards.
+ *
+ * There are 2 channels, currently this driver only supports channel 0 since
+ * there are no boards known to use channel 1.
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#define LRADC_CTRL		0x00
+#define LRADC_INTC		0x04
+#define LRADC_INTS		0x08
+#define LRADC_DATA0		0x0c
+#define LRADC_DATA1		0x10
+
+/* LRADC_CTRL bits */
+#define FIRST_CONVERT_DLY(x)	((x) << 24) /* 8 bits */
+#define CHAN_SELECT(x)		((x) << 22) /* 2 bits */
+#define CONTINUE_TIME_SEL(x)	((x) << 16) /* 4 bits */
+#define KEY_MODE_SEL(x)		((x) << 12) /* 2 bits */
+#define LEVELA_B_CNT(x)		((x) << 8)  /* 4 bits */
+#define HOLD_EN(x)		((x) << 6)
+#define LEVELB_VOL(x)		((x) << 4)  /* 2 bits */
+#define SAMPLE_RATE(x)		((x) << 2)  /* 2 bits */
+#define ENABLE(x)		((x) << 0)
+
+/* LRADC_INTC and LRADC_INTS bits */
+#define CHAN1_KEYUP_IRQ		BIT(12)
+#define CHAN1_ALRDY_HOLD_IRQ	BIT(11)
+#define CHAN1_HOLD_IRQ		BIT(10)
+#define	CHAN1_KEYDOWN_IRQ	BIT(9)
+#define CHAN1_DATA_IRQ		BIT(8)
+#define CHAN0_KEYUP_IRQ		BIT(4)
+#define CHAN0_ALRDY_HOLD_IRQ	BIT(3)
+#define CHAN0_HOLD_IRQ		BIT(2)
+#define	CHAN0_KEYDOWN_IRQ	BIT(1)
+#define CHAN0_DATA_IRQ		BIT(0)
+
+struct sun4i_lradc_keymap {
+	u32 voltage;
+	u32 keycode;
+};
+
+struct sun4i_lradc_data {
+	struct device *dev;
+	struct input_dev *input;
+	void __iomem *base;
+	struct regulator *vref_supply;
+	struct sun4i_lradc_keymap *chan0_map;
+	u32 chan0_map_count;
+	u32 chan0_keycode;
+	u32 vref;
+};
+
+static irqreturn_t sun4i_lradc_irq(int irq, void *dev_id)
+{
+	struct sun4i_lradc_data *lradc = dev_id;
+	u32 i, ints, val, voltage, diff, keycode = 0, closest = 0xffffffff;
+
+	ints  = readl(lradc->base + LRADC_INTS);
+
+	/*
+	 * lradc supports only one keypress at a time, release does not give
+	 * any info as to which key was released, so we cache the keycode.
+	 */
+	if ((ints & CHAN0_KEYDOWN_IRQ) && lradc->chan0_keycode == 0) {
+		val = readl(lradc->base + LRADC_DATA0) & 0x3f;
+		voltage = val * lradc->vref / 63;
+
+		for (i = 0; i < lradc->chan0_map_count; i++) {
+			diff = abs(lradc->chan0_map[i].voltage - voltage);
+			if (diff < closest) {
+				closest = diff;
+				keycode = lradc->chan0_map[i].keycode;
+			}
+		}
+
+		lradc->chan0_keycode = keycode;
+		input_report_key(lradc->input, lradc->chan0_keycode, 1);
+	}
+
+	if (ints & CHAN0_KEYUP_IRQ) {
+		input_report_key(lradc->input, lradc->chan0_keycode, 0);
+		lradc->chan0_keycode = 0;
+	}
+
+	input_sync(lradc->input);
+
+	writel(ints, lradc->base + LRADC_INTS);
+
+	return IRQ_HANDLED;
+}
+
+static int sun4i_lradc_open(struct input_dev *dev)
+{
+	struct sun4i_lradc_data *lradc = input_get_drvdata(dev);
+	int ret;
+
+	ret = regulator_enable(lradc->vref_supply);
+	if (ret)
+		return ret;
+
+	/* lradc Vref internally is divided by 2/3 */
+	lradc->vref = regulator_get_voltage(lradc->vref_supply) * 2 / 3;
+
+	/*
+	 * Set sample time to 4 ms / 250 Hz. Wait 2 * 4 ms for key to
+	 * stabilize on press, wait (1 + 1) * 4 ms for key release
+	 */
+	writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) |
+		SAMPLE_RATE(0) | ENABLE(1), lradc->base + LRADC_CTRL);
+
+	writel(CHAN0_KEYUP_IRQ | CHAN0_KEYDOWN_IRQ, lradc->base + LRADC_INTC);
+
+	return 0;
+}
+
+static void sun4i_lradc_close(struct input_dev *dev)
+{
+	struct sun4i_lradc_data *lradc = input_get_drvdata(dev);
+
+	/* Disable lradc, leave other settings unchanged */
+	writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) |
+		SAMPLE_RATE(2), lradc->base + LRADC_CTRL);
+	writel(0, lradc->base + LRADC_INTC);
+
+	regulator_disable(lradc->vref_supply);
+}
+
+static int sun4i_lradc_probe(struct platform_device *pdev)
+{
+	struct sun4i_lradc_data *lradc;
+	struct device *dev = &pdev->dev;
+	struct device_node *pp, *np = dev->of_node;
+	u32 channel;
+	int i, ret;
+
+	lradc = devm_kzalloc(dev, sizeof(struct sun4i_lradc_data), GFP_KERNEL);
+	if (!lradc)
+		return -ENOMEM;
+
+	lradc->chan0_map_count = of_get_child_count(np);
+	lradc->chan0_map = devm_kmalloc(dev, lradc->chan0_map_count *
+				sizeof(struct sun4i_lradc_keymap), GFP_KERNEL);
+	if (!lradc->chan0_map)
+		return -ENOMEM;
+
+	i = 0;
+	for_each_child_of_node(np, pp) {
+		struct sun4i_lradc_keymap *map = &lradc->chan0_map[i];
+
+		ret = of_property_read_u32(pp, "channel", &channel);
+		if (ret || channel != 0) {
+			dev_err(dev, "%s: Inval channel prop\n", pp->name);
+			return -EINVAL;
+		}
+
+		ret = of_property_read_u32(pp, "voltage", &map->voltage);
+		if (ret) {
+			dev_err(dev, "%s: Inval voltage prop\n", pp->name);
+			return -EINVAL;
+		}
+
+		ret = of_property_read_u32(pp, "linux,code", &map->keycode);
+		if (ret) {
+			dev_err(dev, "%s: Inval linux,code prop\n", pp->name);
+			return -EINVAL;
+		}
+
+		i++;
+	}
+
+	lradc->vref_supply = devm_regulator_get(dev, "vref");
+	if (IS_ERR(lradc->vref_supply))
+		return PTR_ERR(lradc->vref_supply);
+
+	lradc->dev = dev;
+	lradc->input = devm_input_allocate_device(dev);
+	if (!lradc->input)
+		return -ENOMEM;
+
+	lradc->input->name = pdev->name;
+	lradc->input->phys = "sun4i_lradc/input0";
+	lradc->input->open = sun4i_lradc_open;
+	lradc->input->close = sun4i_lradc_close;
+	lradc->input->id.bustype = BUS_HOST;
+	lradc->input->id.vendor = 0x0001;
+	lradc->input->id.product = 0x0001;
+	lradc->input->id.version = 0x0100;
+	lradc->input->evbit[0] =  BIT(EV_SYN) | BIT(EV_KEY);
+	for (i = 0; i < lradc->chan0_map_count; i++)
+		set_bit(lradc->chan0_map[i].keycode, lradc->input->keybit);
+	input_set_drvdata(lradc->input, lradc);
+
+	lradc->base = devm_ioremap_resource(dev,
+			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
+	if (IS_ERR(lradc->base))
+		return PTR_ERR(lradc->base);
+
+	ret = devm_request_irq(dev, platform_get_irq(pdev, 0), sun4i_lradc_irq,
+			       0, "sun4i-lradc-keys", lradc);
+	if (ret)
+		return ret;
+
+	ret = input_register_device(lradc->input);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, lradc);
+	return 0;
+}
+
+static const struct of_device_id sun4i_lradc_of_match[] = {
+	{ .compatible = "allwinner,sun4i-lradc-keys", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sun4i_lradc_of_match);
+
+static struct platform_driver sun4i_lradc_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= "sun4i-lradc-keys",
+		.of_match_table = of_match_ptr(sun4i_lradc_of_match),
+	},
+	.probe	= sun4i_lradc_probe,
+};
+
+module_platform_driver(sun4i_lradc_driver);
+
+MODULE_DESCRIPTION("Allwinner sun4i low res adc attached tablet keys driver");
+MODULE_AUTHOR("Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>");
+MODULE_LICENSE("GPL");
-- 
2.1.0

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Re: [PATCH v2 1/4] input: Add new sun4i-lradc-keys driver

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 14598 bytes --]

Hi Hans,

Thanks, a lot for respinning this.

On Tue, Oct 21, 2014 at 10:24:47AM +0200, Hans de Goede wrote:
> Allwinnner sunxi SoCs have a low resolution adc (called lradc) which is
> specifically designed to have various (tablet) keys (ie home, back, search,
> etc). attached to it using a resistor network. This adds a driver for this.
> 
> There are 2 channels, currently this driver only supports chan0 since there
> are no boards known to use chan1.
> 
> This has been tested on an olimex a10s-olinuxino-micro, a13-olinuxino, and
> a20-olinuxino-micro.
> 
> Signed-off-by: Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> --
> Changes in v2:
> -Change devicetree bindings to use a per key subnode, like gpio-keys does
> ---
>  .../devicetree/bindings/input/sun4i-lradc-keys.txt |  57 +++++
>  MAINTAINERS                                        |   7 +
>  drivers/input/keyboard/Kconfig                     |  10 +
>  drivers/input/keyboard/Makefile                    |   1 +
>  drivers/input/keyboard/sun4i-lradc-keys.c          | 259 +++++++++++++++++++++
>  5 files changed, 334 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
>  create mode 100644 drivers/input/keyboard/sun4i-lradc-keys.c
> 
> diff --git a/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt b/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
> new file mode 100644
> index 0000000..36a141b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
> @@ -0,0 +1,57 @@
> +Allwinner sun4i low res adc attached tablet keys
> +------------------------------------------------
> +
> +Required properties:
> + - compatible: "allwinner,sun4i-lradc-keys"
> + - reg: mmio address range of the chip
> + - interrupts: interrupt to which the chip is connected
> + - vref-supply: powersupply for the lradc reference voltage
> +
> +Each key is represented as a sub-node of "allwinner,sun4i-lradc-keys":
> +
> +Required subnode-properties:
> +	- label: Descriptive name of the key.
> +	- linux,code: Keycode to emit.
> +	- channel: Channel this key is attached to, mut be 0 or 1.
> +	- voltage: Voltage in µV at lradc input when this key is pressed.
> +
> +Example:
> +
> +#include <dt-bindings/input/input.h>
> +
> +	lradc: lradc@01c22800 {
> +		compatible = "allwinner,sun4i-lradc-keys";

You're still using the old pattern for the compatible here, it should
be allwinner,sun4i-a10-lradc-keys.

> +		reg = <0x01c22800 0x100>;
> +		interrupts = <31>;
> +		vref-supply = <&reg_vcc3v0>;
> +		button@19 {

I guess the node address in centivolts aren't really that common,
maybe in mV instead?

> +			label = "Volume Up";
> +			linux,code = <KEY_VOLUMEUP>;
> +			channel = <0>;
> +			voltage = <191274>;
> +		};

And a newline between the nodes please.

> +		button@39 {
> +			label = "Volume Down";
> +			linux,code = <KEY_VOLUMEDOWN>;
> +			channel = <0>;
> +			voltage = <392644>;
> +		};
> +		button@60 {
> +			label = "Menu";
> +			linux,code = <KEY_MENU>;
> +			channel = <0>;
> +			voltage = <601151>;
> +		};
> +		button@80 {
> +			label = "Enter";
> +			linux,code = <KEY_ENTER>;
> +			channel = <0>;
> +			voltage = <795090>;
> +		};
> +		button@98 {
> +			label = "Home";
> +			linux,code = <KEY_HOME>;
> +			channel = <0>;
> +			voltage = <987387>;
> +		};
> +	};
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a20df9b..73d1aef 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8932,6 +8932,13 @@ F:	arch/m68k/sun3*/
>  F:	arch/m68k/include/asm/sun3*
>  F:	drivers/net/ethernet/i825xx/sun3*
>  
> +SUN4I LOW RES ADC ATTACHED TABLET KEYS DRIVER
> +M:	Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> +L:	linux-input-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
> +F:	drivers/input/keyboard/sun4i-lradc-keys.c
> +
>  SUNDANCE NETWORK DRIVER
>  M:	Denis Kirjanov <kda-u1c8ncikuMvVAZt0uhVF+Ni2O/JbrIOy@public.gmane.org>
>  L:	netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
> index a3958c6..2d11b44 100644
> --- a/drivers/input/keyboard/Kconfig
> +++ b/drivers/input/keyboard/Kconfig
> @@ -567,6 +567,16 @@ config KEYBOARD_STMPE
>  	  To compile this driver as a module, choose M here: the module will be
>  	  called stmpe-keypad.
>  
> +config KEYBOARD_SUN4I_LRADC
> +	tristate "Allwinner sun4i low res adc attached tablet keys support"
> +	depends on ARCH_SUNXI
> +	help
> +	  This selects support for the Allwinner low res adc attached tablet
> +	  keys found on Allwinner sunxi SoCs.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called sun4i-lradc-keys.
> +
>  config KEYBOARD_DAVINCI
>  	tristate "TI DaVinci Key Scan"
>  	depends on ARCH_DAVINCI_DM365
> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
> index 0a33456..a35269a 100644
> --- a/drivers/input/keyboard/Makefile
> +++ b/drivers/input/keyboard/Makefile
> @@ -53,6 +53,7 @@ obj-$(CONFIG_KEYBOARD_SPEAR)		+= spear-keyboard.o
>  obj-$(CONFIG_KEYBOARD_STMPE)		+= stmpe-keypad.o
>  obj-$(CONFIG_KEYBOARD_STOWAWAY)		+= stowaway.o
>  obj-$(CONFIG_KEYBOARD_ST_KEYSCAN)	+= st-keyscan.o
> +obj-$(CONFIG_KEYBOARD_SUN4I_LRADC)	+= sun4i-lradc-keys.o
>  obj-$(CONFIG_KEYBOARD_SUNKBD)		+= sunkbd.o
>  obj-$(CONFIG_KEYBOARD_TC3589X)		+= tc3589x-keypad.o
>  obj-$(CONFIG_KEYBOARD_TEGRA)		+= tegra-kbc.o
> diff --git a/drivers/input/keyboard/sun4i-lradc-keys.c b/drivers/input/keyboard/sun4i-lradc-keys.c
> new file mode 100644
> index 0000000..63a1aff
> --- /dev/null
> +++ b/drivers/input/keyboard/sun4i-lradc-keys.c
> @@ -0,0 +1,259 @@
> +/*
> + * Allwinner sun4i low res adc attached tablet keys driver
> + *
> + * Copyright (C) 2014 Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +/*
> + * Allwinnner sunxi SoCs have a lradc which is specifically designed to have
> + * various (tablet) keys (ie home, back, search, etc). attached to it using
> + * a resistor network. This driver is for the keys on such boards.
> + *
> + * There are 2 channels, currently this driver only supports channel 0 since
> + * there are no boards known to use channel 1.
> + */
> +
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/input.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/slab.h>
> +
> +#define LRADC_CTRL		0x00
> +#define LRADC_INTC		0x04
> +#define LRADC_INTS		0x08
> +#define LRADC_DATA0		0x0c
> +#define LRADC_DATA1		0x10
> +
> +/* LRADC_CTRL bits */
> +#define FIRST_CONVERT_DLY(x)	((x) << 24) /* 8 bits */
> +#define CHAN_SELECT(x)		((x) << 22) /* 2 bits */
> +#define CONTINUE_TIME_SEL(x)	((x) << 16) /* 4 bits */
> +#define KEY_MODE_SEL(x)		((x) << 12) /* 2 bits */
> +#define LEVELA_B_CNT(x)		((x) << 8)  /* 4 bits */
> +#define HOLD_EN(x)		((x) << 6)
> +#define LEVELB_VOL(x)		((x) << 4)  /* 2 bits */
> +#define SAMPLE_RATE(x)		((x) << 2)  /* 2 bits */
> +#define ENABLE(x)		((x) << 0)
> +
> +/* LRADC_INTC and LRADC_INTS bits */
> +#define CHAN1_KEYUP_IRQ		BIT(12)
> +#define CHAN1_ALRDY_HOLD_IRQ	BIT(11)
> +#define CHAN1_HOLD_IRQ		BIT(10)
> +#define	CHAN1_KEYDOWN_IRQ	BIT(9)
> +#define CHAN1_DATA_IRQ		BIT(8)
> +#define CHAN0_KEYUP_IRQ		BIT(4)
> +#define CHAN0_ALRDY_HOLD_IRQ	BIT(3)
> +#define CHAN0_HOLD_IRQ		BIT(2)
> +#define	CHAN0_KEYDOWN_IRQ	BIT(1)
> +#define CHAN0_DATA_IRQ		BIT(0)
> +
> +struct sun4i_lradc_keymap {
> +	u32 voltage;
> +	u32 keycode;
> +};
> +
> +struct sun4i_lradc_data {
> +	struct device *dev;
> +	struct input_dev *input;
> +	void __iomem *base;
> +	struct regulator *vref_supply;
> +	struct sun4i_lradc_keymap *chan0_map;
> +	u32 chan0_map_count;
> +	u32 chan0_keycode;
> +	u32 vref;
> +};
> +
> +static irqreturn_t sun4i_lradc_irq(int irq, void *dev_id)
> +{
> +	struct sun4i_lradc_data *lradc = dev_id;
> +	u32 i, ints, val, voltage, diff, keycode = 0, closest = 0xffffffff;
> +
> +	ints  = readl(lradc->base + LRADC_INTS);
> +
> +	/*
> +	 * lradc supports only one keypress at a time, release does not give
> +	 * any info as to which key was released, so we cache the keycode.
> +	 */
> +	if ((ints & CHAN0_KEYDOWN_IRQ) && lradc->chan0_keycode == 0) {
> +		val = readl(lradc->base + LRADC_DATA0) & 0x3f;
> +		voltage = val * lradc->vref / 63;
> +
> +		for (i = 0; i < lradc->chan0_map_count; i++) {
> +			diff = abs(lradc->chan0_map[i].voltage - voltage);
> +			if (diff < closest) {
> +				closest = diff;
> +				keycode = lradc->chan0_map[i].keycode;
> +			}
> +		}
> +
> +		lradc->chan0_keycode = keycode;
> +		input_report_key(lradc->input, lradc->chan0_keycode, 1);
> +	}
> +
> +	if (ints & CHAN0_KEYUP_IRQ) {
> +		input_report_key(lradc->input, lradc->chan0_keycode, 0);
> +		lradc->chan0_keycode = 0;
> +	}
> +
> +	input_sync(lradc->input);
> +
> +	writel(ints, lradc->base + LRADC_INTS);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int sun4i_lradc_open(struct input_dev *dev)
> +{
> +	struct sun4i_lradc_data *lradc = input_get_drvdata(dev);
> +	int ret;
> +
> +	ret = regulator_enable(lradc->vref_supply);
> +	if (ret)
> +		return ret;
> +
> +	/* lradc Vref internally is divided by 2/3 */
> +	lradc->vref = regulator_get_voltage(lradc->vref_supply) * 2 / 3;
> +
> +	/*
> +	 * Set sample time to 4 ms / 250 Hz. Wait 2 * 4 ms for key to
> +	 * stabilize on press, wait (1 + 1) * 4 ms for key release
> +	 */
> +	writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) |
> +		SAMPLE_RATE(0) | ENABLE(1), lradc->base + LRADC_CTRL);
> +
> +	writel(CHAN0_KEYUP_IRQ | CHAN0_KEYDOWN_IRQ, lradc->base + LRADC_INTC);
> +
> +	return 0;
> +}
> +
> +static void sun4i_lradc_close(struct input_dev *dev)
> +{
> +	struct sun4i_lradc_data *lradc = input_get_drvdata(dev);
> +
> +	/* Disable lradc, leave other settings unchanged */
> +	writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) |
> +		SAMPLE_RATE(2), lradc->base + LRADC_CTRL);
> +	writel(0, lradc->base + LRADC_INTC);
> +
> +	regulator_disable(lradc->vref_supply);
> +}
> +
> +static int sun4i_lradc_probe(struct platform_device *pdev)
> +{
> +	struct sun4i_lradc_data *lradc;
> +	struct device *dev = &pdev->dev;
> +	struct device_node *pp, *np = dev->of_node;
> +	u32 channel;
> +	int i, ret;
> +
> +	lradc = devm_kzalloc(dev, sizeof(struct sun4i_lradc_data), GFP_KERNEL);
> +	if (!lradc)
> +		return -ENOMEM;
> +
> +	lradc->chan0_map_count = of_get_child_count(np);
> +	lradc->chan0_map = devm_kmalloc(dev, lradc->chan0_map_count *
> +				sizeof(struct sun4i_lradc_keymap), GFP_KERNEL);
> +	if (!lradc->chan0_map)
> +		return -ENOMEM;
> +
> +	i = 0;
> +	for_each_child_of_node(np, pp) {
> +		struct sun4i_lradc_keymap *map = &lradc->chan0_map[i];
> +
> +		ret = of_property_read_u32(pp, "channel", &channel);
> +		if (ret || channel != 0) {
> +			dev_err(dev, "%s: Inval channel prop\n", pp->name);
> +			return -EINVAL;
> +		}
> +
> +		ret = of_property_read_u32(pp, "voltage", &map->voltage);
> +		if (ret) {
> +			dev_err(dev, "%s: Inval voltage prop\n", pp->name);
> +			return -EINVAL;
> +		}
> +
> +		ret = of_property_read_u32(pp, "linux,code", &map->keycode);
> +		if (ret) {
> +			dev_err(dev, "%s: Inval linux,code prop\n", pp->name);
> +			return -EINVAL;
> +		}
> +
> +		i++;
> +	}
> +
> +	lradc->vref_supply = devm_regulator_get(dev, "vref");
> +	if (IS_ERR(lradc->vref_supply))
> +		return PTR_ERR(lradc->vref_supply);
> +
> +	lradc->dev = dev;
> +	lradc->input = devm_input_allocate_device(dev);
> +	if (!lradc->input)
> +		return -ENOMEM;
> +
> +	lradc->input->name = pdev->name;
> +	lradc->input->phys = "sun4i_lradc/input0";
> +	lradc->input->open = sun4i_lradc_open;
> +	lradc->input->close = sun4i_lradc_close;
> +	lradc->input->id.bustype = BUS_HOST;
> +	lradc->input->id.vendor = 0x0001;
> +	lradc->input->id.product = 0x0001;
> +	lradc->input->id.version = 0x0100;
> +	lradc->input->evbit[0] =  BIT(EV_SYN) | BIT(EV_KEY);
> +	for (i = 0; i < lradc->chan0_map_count; i++)
> +		set_bit(lradc->chan0_map[i].keycode, lradc->input->keybit);
> +	input_set_drvdata(lradc->input, lradc);
> +
> +	lradc->base = devm_ioremap_resource(dev,
> +			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
> +	if (IS_ERR(lradc->base))
> +		return PTR_ERR(lradc->base);
> +
> +	ret = devm_request_irq(dev, platform_get_irq(pdev, 0), sun4i_lradc_irq,
> +			       0, "sun4i-lradc-keys", lradc);
> +	if (ret)
> +		return ret;
> +
> +	ret = input_register_device(lradc->input);
> +	if (ret)
> +		return ret;
> +
> +	platform_set_drvdata(pdev, lradc);
> +	return 0;
> +}
> +
> +static const struct of_device_id sun4i_lradc_of_match[] = {
> +	{ .compatible = "allwinner,sun4i-lradc-keys", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, sun4i_lradc_of_match);
> +
> +static struct platform_driver sun4i_lradc_driver = {
> +	.driver = {
> +		.owner	= THIS_MODULE,

You can drop the owner field, it's already filled by
module_platform_driver.

> +		.name	= "sun4i-lradc-keys",
> +		.of_match_table = of_match_ptr(sun4i_lradc_of_match),
> +	},
> +	.probe	= sun4i_lradc_probe,
> +};
> +
> +module_platform_driver(sun4i_lradc_driver);
> +
> +MODULE_DESCRIPTION("Allwinner sun4i low res adc attached tablet keys driver");
> +MODULE_AUTHOR("Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>");
> +MODULE_LICENSE("GPL");
> -- 
> 2.1.0
> 

Looking good otherwise, thanks!

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH v2 1/4] input: Add new sun4i-lradc-keys driver

[Hans de Goede]

Hi,

On 10/21/2014 07:04 PM, Maxime Ripard wrote:
> Hi Hans,
> 
> Thanks, a lot for respinning this.
> 
> On Tue, Oct 21, 2014 at 10:24:47AM +0200, Hans de Goede wrote:
>> Allwinnner sunxi SoCs have a low resolution adc (called lradc) which is
>> specifically designed to have various (tablet) keys (ie home, back, search,
>> etc). attached to it using a resistor network. This adds a driver for this.
>>
>> There are 2 channels, currently this driver only supports chan0 since there
>> are no boards known to use chan1.
>>
>> This has been tested on an olimex a10s-olinuxino-micro, a13-olinuxino, and
>> a20-olinuxino-micro.
>>
>> Signed-off-by: Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> --
>> Changes in v2:
>> -Change devicetree bindings to use a per key subnode, like gpio-keys does
>> ---
>>  .../devicetree/bindings/input/sun4i-lradc-keys.txt |  57 +++++
>>  MAINTAINERS                                        |   7 +
>>  drivers/input/keyboard/Kconfig                     |  10 +
>>  drivers/input/keyboard/Makefile                    |   1 +
>>  drivers/input/keyboard/sun4i-lradc-keys.c          | 259 +++++++++++++++++++++
>>  5 files changed, 334 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
>>  create mode 100644 drivers/input/keyboard/sun4i-lradc-keys.c
>>
>> diff --git a/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt b/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
>> new file mode 100644
>> index 0000000..36a141b
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
>> @@ -0,0 +1,57 @@
>> +Allwinner sun4i low res adc attached tablet keys
>> +------------------------------------------------
>> +
>> +Required properties:
>> + - compatible: "allwinner,sun4i-lradc-keys"
>> + - reg: mmio address range of the chip
>> + - interrupts: interrupt to which the chip is connected
>> + - vref-supply: powersupply for the lradc reference voltage
>> +
>> +Each key is represented as a sub-node of "allwinner,sun4i-lradc-keys":
>> +
>> +Required subnode-properties:
>> +	- label: Descriptive name of the key.
>> +	- linux,code: Keycode to emit.
>> +	- channel: Channel this key is attached to, mut be 0 or 1.
>> +	- voltage: Voltage in µV at lradc input when this key is pressed.
>> +
>> +Example:
>> +
>> +#include <dt-bindings/input/input.h>
>> +
>> +	lradc: lradc@01c22800 {
>> +		compatible = "allwinner,sun4i-lradc-keys";
> 
> You're still using the old pattern for the compatible here, it should
> be allwinner,sun4i-a10-lradc-keys.

Will fix for the next version.

> 
>> +		reg = <0x01c22800 0x100>;
>> +		interrupts = <31>;
>> +		vref-supply = <&reg_vcc3v0>;
>> +		button@19 {
> 
> I guess the node address in centivolts aren't really that common,
> maybe in mV instead?

Ack for using mV, will fix for the next version.

> 
>> +			label = "Volume Up";
>> +			linux,code = <KEY_VOLUMEUP>;
>> +			channel = <0>;
>> +			voltage = <191274>;
>> +		};
> 
> And a newline between the nodes please.

Will fix for the next version.

>> +		button@39 {
>> +			label = "Volume Down";
>> +			linux,code = <KEY_VOLUMEDOWN>;
>> +			channel = <0>;
>> +			voltage = <392644>;
>> +		};
>> +		button@60 {
>> +			label = "Menu";
>> +			linux,code = <KEY_MENU>;
>> +			channel = <0>;
>> +			voltage = <601151>;
>> +		};
>> +		button@80 {
>> +			label = "Enter";
>> +			linux,code = <KEY_ENTER>;
>> +			channel = <0>;
>> +			voltage = <795090>;
>> +		};
>> +		button@98 {
>> +			label = "Home";
>> +			linux,code = <KEY_HOME>;
>> +			channel = <0>;
>> +			voltage = <987387>;
>> +		};
>> +	};
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index a20df9b..73d1aef 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -8932,6 +8932,13 @@ F:	arch/m68k/sun3*/
>>  F:	arch/m68k/include/asm/sun3*
>>  F:	drivers/net/ethernet/i825xx/sun3*
>>  
>> +SUN4I LOW RES ADC ATTACHED TABLET KEYS DRIVER
>> +M:	Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> +L:	linux-input-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> +S:	Maintained
>> +F:	Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
>> +F:	drivers/input/keyboard/sun4i-lradc-keys.c
>> +
>>  SUNDANCE NETWORK DRIVER
>>  M:	Denis Kirjanov <kda-u1c8ncikuMvVAZt0uhVF+Ni2O/JbrIOy@public.gmane.org>
>>  L:	netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
>> index a3958c6..2d11b44 100644
>> --- a/drivers/input/keyboard/Kconfig
>> +++ b/drivers/input/keyboard/Kconfig
>> @@ -567,6 +567,16 @@ config KEYBOARD_STMPE
>>  	  To compile this driver as a module, choose M here: the module will be
>>  	  called stmpe-keypad.
>>  
>> +config KEYBOARD_SUN4I_LRADC
>> +	tristate "Allwinner sun4i low res adc attached tablet keys support"
>> +	depends on ARCH_SUNXI
>> +	help
>> +	  This selects support for the Allwinner low res adc attached tablet
>> +	  keys found on Allwinner sunxi SoCs.
>> +
>> +	  To compile this driver as a module, choose M here: the
>> +	  module will be called sun4i-lradc-keys.
>> +
>>  config KEYBOARD_DAVINCI
>>  	tristate "TI DaVinci Key Scan"
>>  	depends on ARCH_DAVINCI_DM365
>> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
>> index 0a33456..a35269a 100644
>> --- a/drivers/input/keyboard/Makefile
>> +++ b/drivers/input/keyboard/Makefile
>> @@ -53,6 +53,7 @@ obj-$(CONFIG_KEYBOARD_SPEAR)		+= spear-keyboard.o
>>  obj-$(CONFIG_KEYBOARD_STMPE)		+= stmpe-keypad.o
>>  obj-$(CONFIG_KEYBOARD_STOWAWAY)		+= stowaway.o
>>  obj-$(CONFIG_KEYBOARD_ST_KEYSCAN)	+= st-keyscan.o
>> +obj-$(CONFIG_KEYBOARD_SUN4I_LRADC)	+= sun4i-lradc-keys.o
>>  obj-$(CONFIG_KEYBOARD_SUNKBD)		+= sunkbd.o
>>  obj-$(CONFIG_KEYBOARD_TC3589X)		+= tc3589x-keypad.o
>>  obj-$(CONFIG_KEYBOARD_TEGRA)		+= tegra-kbc.o
>> diff --git a/drivers/input/keyboard/sun4i-lradc-keys.c b/drivers/input/keyboard/sun4i-lradc-keys.c
>> new file mode 100644
>> index 0000000..63a1aff
>> --- /dev/null
>> +++ b/drivers/input/keyboard/sun4i-lradc-keys.c
>> @@ -0,0 +1,259 @@
>> +/*
>> + * Allwinner sun4i low res adc attached tablet keys driver
>> + *
>> + * Copyright (C) 2014 Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +/*
>> + * Allwinnner sunxi SoCs have a lradc which is specifically designed to have
>> + * various (tablet) keys (ie home, back, search, etc). attached to it using
>> + * a resistor network. This driver is for the keys on such boards.
>> + *
>> + * There are 2 channels, currently this driver only supports channel 0 since
>> + * there are no boards known to use channel 1.
>> + */
>> +
>> +#include <linux/err.h>
>> +#include <linux/init.h>
>> +#include <linux/input.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/module.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/slab.h>
>> +
>> +#define LRADC_CTRL		0x00
>> +#define LRADC_INTC		0x04
>> +#define LRADC_INTS		0x08
>> +#define LRADC_DATA0		0x0c
>> +#define LRADC_DATA1		0x10
>> +
>> +/* LRADC_CTRL bits */
>> +#define FIRST_CONVERT_DLY(x)	((x) << 24) /* 8 bits */
>> +#define CHAN_SELECT(x)		((x) << 22) /* 2 bits */
>> +#define CONTINUE_TIME_SEL(x)	((x) << 16) /* 4 bits */
>> +#define KEY_MODE_SEL(x)		((x) << 12) /* 2 bits */
>> +#define LEVELA_B_CNT(x)		((x) << 8)  /* 4 bits */
>> +#define HOLD_EN(x)		((x) << 6)
>> +#define LEVELB_VOL(x)		((x) << 4)  /* 2 bits */
>> +#define SAMPLE_RATE(x)		((x) << 2)  /* 2 bits */
>> +#define ENABLE(x)		((x) << 0)
>> +
>> +/* LRADC_INTC and LRADC_INTS bits */
>> +#define CHAN1_KEYUP_IRQ		BIT(12)
>> +#define CHAN1_ALRDY_HOLD_IRQ	BIT(11)
>> +#define CHAN1_HOLD_IRQ		BIT(10)
>> +#define	CHAN1_KEYDOWN_IRQ	BIT(9)
>> +#define CHAN1_DATA_IRQ		BIT(8)
>> +#define CHAN0_KEYUP_IRQ		BIT(4)
>> +#define CHAN0_ALRDY_HOLD_IRQ	BIT(3)
>> +#define CHAN0_HOLD_IRQ		BIT(2)
>> +#define	CHAN0_KEYDOWN_IRQ	BIT(1)
>> +#define CHAN0_DATA_IRQ		BIT(0)
>> +
>> +struct sun4i_lradc_keymap {
>> +	u32 voltage;
>> +	u32 keycode;
>> +};
>> +
>> +struct sun4i_lradc_data {
>> +	struct device *dev;
>> +	struct input_dev *input;
>> +	void __iomem *base;
>> +	struct regulator *vref_supply;
>> +	struct sun4i_lradc_keymap *chan0_map;
>> +	u32 chan0_map_count;
>> +	u32 chan0_keycode;
>> +	u32 vref;
>> +};
>> +
>> +static irqreturn_t sun4i_lradc_irq(int irq, void *dev_id)
>> +{
>> +	struct sun4i_lradc_data *lradc = dev_id;
>> +	u32 i, ints, val, voltage, diff, keycode = 0, closest = 0xffffffff;
>> +
>> +	ints  = readl(lradc->base + LRADC_INTS);
>> +
>> +	/*
>> +	 * lradc supports only one keypress at a time, release does not give
>> +	 * any info as to which key was released, so we cache the keycode.
>> +	 */
>> +	if ((ints & CHAN0_KEYDOWN_IRQ) && lradc->chan0_keycode == 0) {
>> +		val = readl(lradc->base + LRADC_DATA0) & 0x3f;
>> +		voltage = val * lradc->vref / 63;
>> +
>> +		for (i = 0; i < lradc->chan0_map_count; i++) {
>> +			diff = abs(lradc->chan0_map[i].voltage - voltage);
>> +			if (diff < closest) {
>> +				closest = diff;
>> +				keycode = lradc->chan0_map[i].keycode;
>> +			}
>> +		}
>> +
>> +		lradc->chan0_keycode = keycode;
>> +		input_report_key(lradc->input, lradc->chan0_keycode, 1);
>> +	}
>> +
>> +	if (ints & CHAN0_KEYUP_IRQ) {
>> +		input_report_key(lradc->input, lradc->chan0_keycode, 0);
>> +		lradc->chan0_keycode = 0;
>> +	}
>> +
>> +	input_sync(lradc->input);
>> +
>> +	writel(ints, lradc->base + LRADC_INTS);
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static int sun4i_lradc_open(struct input_dev *dev)
>> +{
>> +	struct sun4i_lradc_data *lradc = input_get_drvdata(dev);
>> +	int ret;
>> +
>> +	ret = regulator_enable(lradc->vref_supply);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/* lradc Vref internally is divided by 2/3 */
>> +	lradc->vref = regulator_get_voltage(lradc->vref_supply) * 2 / 3;
>> +
>> +	/*
>> +	 * Set sample time to 4 ms / 250 Hz. Wait 2 * 4 ms for key to
>> +	 * stabilize on press, wait (1 + 1) * 4 ms for key release
>> +	 */
>> +	writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) |
>> +		SAMPLE_RATE(0) | ENABLE(1), lradc->base + LRADC_CTRL);
>> +
>> +	writel(CHAN0_KEYUP_IRQ | CHAN0_KEYDOWN_IRQ, lradc->base + LRADC_INTC);
>> +
>> +	return 0;
>> +}
>> +
>> +static void sun4i_lradc_close(struct input_dev *dev)
>> +{
>> +	struct sun4i_lradc_data *lradc = input_get_drvdata(dev);
>> +
>> +	/* Disable lradc, leave other settings unchanged */
>> +	writel(FIRST_CONVERT_DLY(2) | LEVELA_B_CNT(1) | HOLD_EN(1) |
>> +		SAMPLE_RATE(2), lradc->base + LRADC_CTRL);
>> +	writel(0, lradc->base + LRADC_INTC);
>> +
>> +	regulator_disable(lradc->vref_supply);
>> +}
>> +
>> +static int sun4i_lradc_probe(struct platform_device *pdev)
>> +{
>> +	struct sun4i_lradc_data *lradc;
>> +	struct device *dev = &pdev->dev;
>> +	struct device_node *pp, *np = dev->of_node;
>> +	u32 channel;
>> +	int i, ret;
>> +
>> +	lradc = devm_kzalloc(dev, sizeof(struct sun4i_lradc_data), GFP_KERNEL);
>> +	if (!lradc)
>> +		return -ENOMEM;
>> +
>> +	lradc->chan0_map_count = of_get_child_count(np);
>> +	lradc->chan0_map = devm_kmalloc(dev, lradc->chan0_map_count *
>> +				sizeof(struct sun4i_lradc_keymap), GFP_KERNEL);
>> +	if (!lradc->chan0_map)
>> +		return -ENOMEM;
>> +
>> +	i = 0;
>> +	for_each_child_of_node(np, pp) {
>> +		struct sun4i_lradc_keymap *map = &lradc->chan0_map[i];
>> +
>> +		ret = of_property_read_u32(pp, "channel", &channel);
>> +		if (ret || channel != 0) {
>> +			dev_err(dev, "%s: Inval channel prop\n", pp->name);
>> +			return -EINVAL;
>> +		}
>> +
>> +		ret = of_property_read_u32(pp, "voltage", &map->voltage);
>> +		if (ret) {
>> +			dev_err(dev, "%s: Inval voltage prop\n", pp->name);
>> +			return -EINVAL;
>> +		}
>> +
>> +		ret = of_property_read_u32(pp, "linux,code", &map->keycode);
>> +		if (ret) {
>> +			dev_err(dev, "%s: Inval linux,code prop\n", pp->name);
>> +			return -EINVAL;
>> +		}
>> +
>> +		i++;
>> +	}
>> +
>> +	lradc->vref_supply = devm_regulator_get(dev, "vref");
>> +	if (IS_ERR(lradc->vref_supply))
>> +		return PTR_ERR(lradc->vref_supply);
>> +
>> +	lradc->dev = dev;
>> +	lradc->input = devm_input_allocate_device(dev);
>> +	if (!lradc->input)
>> +		return -ENOMEM;
>> +
>> +	lradc->input->name = pdev->name;
>> +	lradc->input->phys = "sun4i_lradc/input0";
>> +	lradc->input->open = sun4i_lradc_open;
>> +	lradc->input->close = sun4i_lradc_close;
>> +	lradc->input->id.bustype = BUS_HOST;
>> +	lradc->input->id.vendor = 0x0001;
>> +	lradc->input->id.product = 0x0001;
>> +	lradc->input->id.version = 0x0100;
>> +	lradc->input->evbit[0] =  BIT(EV_SYN) | BIT(EV_KEY);
>> +	for (i = 0; i < lradc->chan0_map_count; i++)
>> +		set_bit(lradc->chan0_map[i].keycode, lradc->input->keybit);
>> +	input_set_drvdata(lradc->input, lradc);
>> +
>> +	lradc->base = devm_ioremap_resource(dev,
>> +			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
>> +	if (IS_ERR(lradc->base))
>> +		return PTR_ERR(lradc->base);
>> +
>> +	ret = devm_request_irq(dev, platform_get_irq(pdev, 0), sun4i_lradc_irq,
>> +			       0, "sun4i-lradc-keys", lradc);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = input_register_device(lradc->input);
>> +	if (ret)
>> +		return ret;
>> +
>> +	platform_set_drvdata(pdev, lradc);
>> +	return 0;
>> +}
>> +
>> +static const struct of_device_id sun4i_lradc_of_match[] = {
>> +	{ .compatible = "allwinner,sun4i-lradc-keys", },
>> +	{ /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(of, sun4i_lradc_of_match);
>> +
>> +static struct platform_driver sun4i_lradc_driver = {
>> +	.driver = {
>> +		.owner	= THIS_MODULE,
> 
> You can drop the owner field, it's already filled by
> module_platform_driver.

Will fix for the next version.

> 
>> +		.name	= "sun4i-lradc-keys",
>> +		.of_match_table = of_match_ptr(sun4i_lradc_of_match),
>> +	},
>> +	.probe	= sun4i_lradc_probe,
>> +};
>> +
>> +module_platform_driver(sun4i_lradc_driver);
>> +
>> +MODULE_DESCRIPTION("Allwinner sun4i low res adc attached tablet keys driver");
>> +MODULE_AUTHOR("Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>");
>> +MODULE_LICENSE("GPL");
>> -- 
>> 2.1.0
>>
> 
> Looking good otherwise, thanks!

Thanks for the review.

Regards,

Hans

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