Input: add driver for Zeitec ZET6223

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>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

5 files changed, 312 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/input/touchscreen/zet6223.txt b/Documentation/devicetree/bindings/input/touchscreen/zet6223.txt
new file mode 100644
index 000000000000..fe6a1feef703
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/zet6223.txt
@@ -0,0 +1,32 @@
+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:
+
+- vio-supply              : Specification for VIO supply (1.8V or 3.3V,
+                            depending on system interface needs).
+- vcc-supply              : Specification for 3.3V VCC supply.
+- 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/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 16d3b5e7f5d1..e6f63f4a0d6d 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -329,6 +329,7 @@ xes	Extreme Engineering Solutions (X-ES)
 xillybus        Xillybus Ltd.
 xlnx    Xilinx
 zarlink Zarlink Semiconductor
+zeitec  ZEITEC Semiconductor Co., LTD.
 zii     Zodiac Inflight Innovations
 zte     ZTE Corp.
 zyxel   ZyXEL Communications Corp.
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 8650c94e29d0..033599777651 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -1165,6 +1165,17 @@ config TOUCHSCREEN_TPS6507X
           To compile this driver as a module, choose M here: the
           module will be called tps6507x_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.
+
 config TOUCHSCREEN_ZFORCE
         tristate "Neonode zForce infrared touchscreens"
         depends on I2C
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index e41e3c7aa427..b622e5344137 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -95,6 +95,7 @@ obj-$(CONFIG_TOUCHSCREEN_WM97XX_ZYLONITE)	+= zylonite-wm97xx.o
 obj-$(CONFIG_TOUCHSCREEN_W90X900)       += w90p910_ts.o
 obj-$(CONFIG_TOUCHSCREEN_SX8654)        += sx8654.o
 obj-$(CONFIG_TOUCHSCREEN_TPS6507X)      += tps6507x-ts.o
+obj-$(CONFIG_TOUCHSCREEN_ZET6223)       += zet6223.o
 obj-$(CONFIG_TOUCHSCREEN_ZFORCE)        += zforce_ts.o
 obj-$(CONFIG_TOUCHSCREEN_COLIBRI_VF50)  += colibri-vf50-ts.o
 obj-$(CONFIG_TOUCHSCREEN_ROHM_BU21023)  += rohm_bu21023.o
diff --git a/drivers/input/touchscreen/zet6223.c b/drivers/input/touchscreen/zet6223.c
new file mode 100644
index 000000000000..e7fb00b511ec
--- /dev/null
+++ b/drivers/input/touchscreen/zet6223.c
@@ -0,0 +1,267 @@
+/*
+ * 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 <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <asm/unaligned.h>
+
+#define ZET6223_MAX_FINGERS             16
+#define ZET6223_MAX_PKT_SIZE            (3 + 4 * ZET6223_MAX_FINGERS)
+
+#define ZET6223_CMD_INFO                0xB2
+#define ZET6223_CMD_INFO_LENGTH         17
+#define ZET6223_VALID_PACKET            0x3c
+
+#define ZET6223_POWER_ON_DELAY_MSEC     30
+
+struct zet6223_ts {
+        struct i2c_client *client;
+        struct input_dev *input;
+        struct regulator *vcc;
+        struct regulator *vio;
+        struct touchscreen_properties prop;
+        struct regulator_bulk_data supplies[2];
+        u16 max_x;
+        u16 max_y;
+        u8 fingernum;
+};
+
+static int zet6223_start(struct input_dev *dev)
+{
+        struct zet6223_ts *ts = input_get_drvdata(dev);
+
+        enable_irq(ts->client->irq);
+
+        return 0;
+}
+
+static void zet6223_stop(struct input_dev *dev)
+{
+        struct zet6223_ts *ts = input_get_drvdata(dev);
+
+        disable_irq(ts->client->irq);
+}
+
+static irqreturn_t zet6223_irq(int irq, void *dev_id)
+{
+        struct zet6223_ts *ts = dev_id;
+        u16 finger_bits;
+
+        /*
+         * First 3 bytes are an identifier, two bytes of finger data.
+         * X, Y data per finger is 4 bytes.
+         */
+        u8 bufsize = 3 + 4 * ts->fingernum;
+        u8 buf[ZET6223_MAX_PKT_SIZE];
+        int i;
+        int ret;
+        int error;
+
+        ret = i2c_master_recv(ts->client, buf, bufsize);
+        if (ret != bufsize) {
+                error = ret < 0 ? ret : -EIO;
+                dev_err_ratelimited(&ts->client->dev,
+                                    "Error reading input data: %d\n", error);
+                return IRQ_HANDLED;
+        }
+
+        if (buf[0] != ZET6223_VALID_PACKET)
+                return IRQ_HANDLED;
+
+        finger_bits = get_unaligned_be16(buf + 1);
+        for (i = 0; i < ts->fingernum; i++) {
+                if (!(finger_bits & BIT(15 - i)))
+                        continue;
+
+                input_mt_slot(ts->input, i);
+                input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
+                input_event(ts->input, EV_ABS, ABS_MT_POSITION_X,
+                                ((buf[i + 3] >> 4) << 8) + buf[i + 4]);
+                input_event(ts->input, EV_ABS, ABS_MT_POSITION_Y,
+                                ((buf[i + 3] & 0xF) << 8) + buf[i + 5]);
+        }
+
+        input_mt_sync_frame(ts->input);
+        input_sync(ts->input);
+
+        return IRQ_HANDLED;
+}
+
+static void zet6223_power_off(void *_ts)
+{
+        struct zet6223_ts *ts = _ts;
+
+        regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
+}
+
+static int zet6223_power_on(struct zet6223_ts *ts)
+{
+        struct device *dev = &ts->client->dev;
+        int error;
+
+        ts->supplies[0].supply = "vio";
+        ts->supplies[1].supply = "vcc";
+
+        error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->supplies),
+                                        ts->supplies);
+        if (error)
+                return error;
+
+        error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
+        if (error)
+                return error;
+
+        msleep(ZET6223_POWER_ON_DELAY_MSEC);
+
+        error = devm_add_action_or_reset(dev, zet6223_power_off, ts);
+        if (error) {
+                dev_err(dev, "failed to install poweroff action: %d\n", error);
+                return error;
+        }
+
+        return 0;
+}
+
+static int zet6223_query_device(struct zet6223_ts *ts)
+{
+        u8 buf[ZET6223_CMD_INFO_LENGTH];
+        u8 cmd = ZET6223_CMD_INFO;
+        int ret;
+        int error;
+
+        ret = i2c_master_send(ts->client, &cmd, sizeof(cmd));
+        if (ret != sizeof(cmd)) {
+                error = ret < 0 ? ret : -EIO;
+                dev_err(&ts->client->dev,
+                        "touchpanel info cmd failed: %d\n", error);
+                return error;
+        }
+
+        ret = i2c_master_recv(ts->client, buf, sizeof(buf));
+        if (ret != sizeof(buf)) {
+                error = ret < 0 ? ret : -EIO;
+                dev_err(&ts->client->dev,
+                        "failed to retrieve touchpanel info: %d\n", error);
+                return error;
+        }
+
+        ts->fingernum = buf[15] & 0x7F;
+        if (ts->fingernum > ZET6223_MAX_FINGERS) {
+                dev_warn(&ts->client->dev,
+                         "touchpanel reports %d fingers, limiting to %d\n",
+                         ts->fingernum, ZET6223_MAX_FINGERS);
+                ts->fingernum = ZET6223_MAX_FINGERS;
+        }
+
+        ts->max_x = get_unaligned_le16(&buf[8]);
+        ts->max_y = get_unaligned_le16(&buf[10]);
+
+        return 0;
+}
+
+static int zet6223_probe(struct i2c_client *client,
+                         const struct i2c_device_id *id)
+{
+        struct device *dev = &client->dev;
+        struct zet6223_ts *ts;
+        struct input_dev *input;
+        int error;
+
+        if (!client->irq) {
+                dev_err(dev, "no irq specified\n");
+                return -EINVAL;
+        }
+
+        ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+        if (!ts)
+                return -ENOMEM;
+
+        ts->client = client;
+
+        error = zet6223_power_on(ts);
+        if (error)
+                return error;
+
+        error = zet6223_query_device(ts);
+        if (error)
+                return error;
+
+        ts->input = input = devm_input_allocate_device(dev);
+        if (!input)
+                return -ENOMEM;
+
+        input_set_drvdata(input, ts);
+
+        input->name = client->name;
+        input->id.bustype = BUS_I2C;
+        input->open = zet6223_start;
+        input->close = zet6223_stop;
+
+        input_set_abs_params(input, ABS_MT_POSITION_X, 0, ts->max_x, 0, 0);
+        input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ts->max_y, 0, 0);
+
+        touchscreen_parse_properties(input, true, &ts->prop);
+
+        error = input_mt_init_slots(input, ts->fingernum,
+                                    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+        if (error)
+                return error;
+
+        error = devm_request_threaded_irq(dev, client->irq, NULL, zet6223_irq,
+                                          IRQF_ONESHOT, client->name, ts);
+        if (error) {
+                dev_err(dev, "failed to request irq %d: %d\n",
+                        client->irq, error);
+                return error;
+        }
+
+        zet6223_stop(input);
+
+        error = input_register_device(input);
+        if (error)
+                return error;
+
+        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");