[PATCH 1/2] input: touchscreen: add driver for Zeitec ZET6223

* [PATCH 1/2] input: touchscreen: add driver for Zeitec ZET6223
@ 2016-12-23 16:32 Jelle van der Waa
  2016-12-23 16:32 ` [PATCH 2/2] devicetree: add vendor prefix for Zeitec Jelle van der Waa
       [not found] ` <20161223163214.7716-1-jelle-oJJ1AqDjjO4@public.gmane.org>
  0 siblings, 2 replies; 15+ messages in thread
From: Jelle van der Waa @ 2016-12-23 16:32 UTC (permalink / raw)
  To: Rob Herring, Dmitry Torokhov, linux-input, devicetree; +Cc: Jelle van der Waa

This is a basic driver for the Zeitec ZET6223 I2C touchscreen
controllers. The driver does not support firmware loading, which is not
required for all tablets which contain this chip.

Signed-off-by: Jelle van der Waa <jelle@vdwaa.nl>
---
 .../bindings/input/touchscreen/zet6223.txt         |  29 +++
 drivers/input/touchscreen/Kconfig                  |  11 ++
 drivers/input/touchscreen/Makefile                 |   1 +
 drivers/input/touchscreen/zet6223.c                | 198 +++++++++++++++++++++
 4 files changed, 239 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/zet6223.txt
 create mode 100644 drivers/input/touchscreen/zet6223.c

diff --git a/Documentation/devicetree/bindings/input/touchscreen/zet6223.txt b/Documentation/devicetree/bindings/input/touchscreen/zet6223.txt
new file mode 100644
index 000000000000..cc0f7d06bc8b
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/zet6223.txt
@@ -0,0 +1,29 @@
+Zeitec ZET6223 I2C touchscreen controller
+
+Required properties:
+ - compatible            : "zeitec,zet6223"
+ - reg                   : I2C slave address of the chip (0x76)
+ - interrupt-parent      : a phandle pointing to the interrupt controller
+                           serving the interrupt for this chip
+ - interrupts            : interrupt specification for the zet6223 interrupt
+
+Optional properties:
+
+- touchscreen-size-x     : See touchscreen.txt
+- touchscreen-size-y     : See touchscreen.txt
+- touchscreen-inverted-x  : See touchscreen.txt
+- touchscreen-inverted-y  : See touchscreen.txt
+- touchscreen-swapped-x-y : See touchscreen.txt
+
+Example:
+
+i2c@00000000 {
+
+       zet6223: touchscreen@76 {
+               compatible = "zeitec,zet6223";
+               reg = <0x76>;
+               interrupt-parent = <&pio>;
+               interrupts = <6 11 IRQ_TYPE_EDGE_FALLING>
+       };
+
+};
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index efca0133e266..3c70adfe676d 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -1214,4 +1214,15 @@ config TOUCHSCREEN_ROHM_BU21023
 	  To compile this driver as a module, choose M here: the
 	  module will be called bu21023_ts.
 
+config TOUCHSCREEN_ZET6223
+       tristate "Zeitec ZET6223 touchscreen driver"
+       depends on I2C
+       help
+         Say Y here if you have a touchscreen using Zeitec ZET6223
+
+         If unsure, say N.
+
+         To compile this driver as a module, choose M here: the
+         module will be called zet6223.
+
 endif
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 81b86451782d..11f8953613cd 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -99,3 +99,4 @@ obj-$(CONFIG_TOUCHSCREEN_TPS6507X)	+= tps6507x-ts.o
 obj-$(CONFIG_TOUCHSCREEN_ZFORCE)	+= zforce_ts.o
 obj-$(CONFIG_TOUCHSCREEN_COLIBRI_VF50)	+= colibri-vf50-ts.o
 obj-$(CONFIG_TOUCHSCREEN_ROHM_BU21023)	+= rohm_bu21023.o
+obj-$(CONFIG_TOUCHSCREEN_ZET6223)       += zet6223.o
diff --git a/drivers/input/touchscreen/zet6223.c b/drivers/input/touchscreen/zet6223.c
new file mode 100644
index 000000000000..aecae06877cf
--- /dev/null
+++ b/drivers/input/touchscreen/zet6223.c
@@ -0,0 +1,198 @@
+/*
+ * Copyright (C) 2016, Jelle van der Waa <jelle@vdwaa.nl>
+ *
+ *  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.
+ */
+
+#include <asm/unaligned.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/module.h>
+
+#define ZET6223_CMD_INFO 0xB2
+#define ZET6223_CMD_INFO_LENGTH 17
+#define ZET6223_VALID_PACKET 0x3c
+
+struct zet6223_data {
+	struct i2c_client *client;
+	struct input_dev *input;
+	struct touchscreen_properties prop;
+	u8 fingernum;
+};
+
+static int zet6223_start(struct input_dev *dev)
+{
+	struct zet6223_data *data = input_get_drvdata(dev);
+
+	enable_irq(data->client->irq);
+
+	return 0;
+}
+
+static void zet6223_stop(struct input_dev *dev)
+{
+	struct zet6223_data *data = input_get_drvdata(dev);
+
+	disable_irq(data->client->irq);
+}
+
+static irqreturn_t irqreturn_t_zet6223(int irq, void *dev_id)
+{
+	struct zet6223_data *data = dev_id;
+	struct device *dev = &data->client->dev;
+	/*
+	 * First 3 bytes are an identifier, two bytes of finger data.
+	 * X, Y data per finger is 4 bytes.
+	 */
+	u8 bufsize = 3 + 4 * data->fingernum;
+	u8 buf[bufsize];
+	u8 i;
+	u16 finger_bits;
+	int ret;
+
+	ret = i2c_master_recv(data->client, buf, bufsize);
+	if (ret != bufsize) {
+		dev_err_ratelimited(dev, "Error reading input data: %d\n", ret);
+		return IRQ_HANDLED;
+	}
+
+	if (buf[0] != ZET6223_VALID_PACKET)
+		return IRQ_HANDLED;
+
+	finger_bits = get_unaligned_be16(buf + 1);
+	for (i = 0; i < data->fingernum; i++) {
+		if (!(finger_bits & BIT(15 - i)))
+			continue;
+
+		input_mt_slot(data->input, i);
+		input_mt_report_slot_state(data->input, MT_TOOL_FINGER, true);
+		input_event(data->input, EV_ABS, ABS_MT_POSITION_X,
+				((buf[i + 3] >> 4) << 8) + buf[i + 4]);
+		input_event(data->input, EV_ABS, ABS_MT_POSITION_Y,
+				((buf[i + 3] & 0xF) << 8) + buf[i + 5]);
+	}
+
+	input_mt_sync_frame(data->input);
+	input_sync(data->input);
+
+	return IRQ_HANDLED;
+}
+
+static int zet6223_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct zet6223_data *data;
+	struct input_dev *input;
+	u8 buf[ZET6223_CMD_INFO_LENGTH];
+	u8 cmd = ZET6223_CMD_INFO;
+	int ret;
+
+	if (!client->irq) {
+		dev_err(dev, "Error no irq specified\n");
+		return -EINVAL;
+	}
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	ret = i2c_master_send(client, &cmd, 1);
+	if (ret < 0) {
+		dev_err(dev, "touchpanel info cmd failed: %d\n", ret);
+		return -ENODEV;
+	}
+
+	ret = i2c_master_recv(client, buf, ZET6223_CMD_INFO_LENGTH);
+	if (ret < 0) {
+		dev_err(dev, "cannot retrieve touchpanel info: %d\n", ret);
+		return -ENODEV;
+	}
+
+	data->fingernum = buf[15] & 0x7F;
+	if (data->fingernum > 16) {
+		data->fingernum = 16;
+		dev_warn(dev, "touchpanel reports more then 16 fingers, limit to 16");
+	}
+
+	input = devm_input_allocate_device(dev);
+	if (!input)
+		return -ENOMEM;
+
+	input_set_abs_params(input, ABS_MT_POSITION_X, 0,
+			get_unaligned_le16(&buf[8]), 0, 0);
+	input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
+			get_unaligned_le16(&buf[10]), 0, 0);
+	touchscreen_parse_properties(input, true, &data->prop);
+
+	input->name = client->name;
+	input->id.bustype = BUS_I2C;
+	input->dev.parent = dev;
+	input->open = zet6223_start;
+	input->close = zet6223_stop;
+
+	ret = input_mt_init_slots(input, data->fingernum,
+		INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+	if (ret)
+		return ret;
+
+	data->client = client;
+	data->input = input;
+
+	input_set_drvdata(input, data);
+
+	ret = devm_request_threaded_irq(dev, client->irq, NULL,
+			irqreturn_t_zet6223, IRQF_ONESHOT, client->name, data);
+	if (ret) {
+		dev_err(dev, "Error requesting irq: %d\n", ret);
+		return ret;
+	}
+
+	zet6223_stop(input);
+
+	ret = input_register_device(input);
+	if (ret)
+		return ret;
+
+	i2c_set_clientdata(client, data);
+
+	return 0;
+}
+
+static const struct of_device_id zet6223_of_match[] = {
+	{ .compatible = "zeitec", "zet6223" },
+	{ }
+};
+
+static const struct i2c_device_id zet6223_id[] = {
+	{ "zet6223", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, zet6223_id);
+
+static struct i2c_driver zet6223_driver = {
+	.driver = {
+		.name = "zet6223",
+		.of_match_table = zet6223_of_match,
+	},
+	.probe = zet6223_probe,
+	.id_table = zet6223_id
+};
+
+module_i2c_driver(zet6223_driver);
+
+MODULE_AUTHOR("Jelle van der Waa <jelle@vdwaa.nl>");
+MODULE_DESCRIPTION("ZEITEC zet622x I2C touchscreen driver");
+MODULE_LICENSE("GPL");
-- 
2.11.0


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