[PATCH resend 5/5] input: touchscreen: Add support for Elan eKTF2127 touchscreen controller
Hans de Goede
hdegoede at redhat.com
Sun Sep 11 11:44:08 PDT 2016
From: Siebren Vroegindeweij <siebren.vroegindeweij at hotmail.com>
This adds a driver for the Elan eKTF2127 touchscreen controller,
which speaks an i2c protocol which is distinctly different from
the already supported eKTH controllers.
Signed-off-by: Michel Verlaan <michel.verl at gmail.com>
Signed-off-by: Siebren Vroegindeweij <siebren.vroegindeweij at hotmail.com>
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
Acked-by: Rob Herring <robh at kernel.org>
---
Changes in v2:
-Improve devicetree bindings document
-Use touchscreen_parse_properties and touchscreen_report_pos instead of DIY
-Remove a bunch of unused defines (copy and paste leftover from chipone driver)
-Some other minor cleanups and review comments addressed
-Add defines for some command / address hex-values
-Check packet header in interrupt handler
---
.../bindings/input/touchscreen/ektf2127.txt | 27 ++
drivers/input/touchscreen/Kconfig | 12 +
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/ektf2127.c | 333 +++++++++++++++++++++
4 files changed, 373 insertions(+)
create mode 100644 Documentation/devicetree/bindings/input/touchscreen/ektf2127.txt
create mode 100644 drivers/input/touchscreen/ektf2127.c
diff --git a/Documentation/devicetree/bindings/input/touchscreen/ektf2127.txt b/Documentation/devicetree/bindings/input/touchscreen/ektf2127.txt
new file mode 100644
index 0000000..70a949b
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/ektf2127.txt
@@ -0,0 +1,27 @@
+* Elan eKTF2127 I2C touchscreen controller
+
+Required properties:
+ - compatible : "elan,ektf2127"
+ - reg : I2C slave address of the chip (0x40)
+ - interrupt-parent : a phandle pointing to the interrupt controller
+ serving the interrupt for this chip
+ - interrupts : interrupt specification for the ektf2127 interrupt
+ - power-gpios : GPIO specification for the pin connected to the
+ ektf2127's wake input. This needs to be driven high
+ to take ektf2127 out of it's low power state
+
+For additional optional properties see: touchscreen.txt
+
+Example:
+
+i2c at 00000000 {
+ ektf2127: touchscreen at 15 {
+ compatible = "elan,ektf2127";
+ reg = <0x15>;
+ interrupt-parent = <&pio>;
+ interrupts = <6 11 IRQ_TYPE_EDGE_FALLING>;
+ power-gpios = <&pio 1 3 GPIO_ACTIVE_HIGH>;
+ touchscreen-inverted-x;
+ touchscreen-swapped-x-y;
+ };
+};
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 3b3d07a..880aa50 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -396,6 +396,18 @@ config TOUCHSCREEN_ELAN
To compile this driver as a module, choose M here: the
module will be called elants_i2c.
+config TOUCHSCREEN_EKTF2127
+ tristate "Elan eKTF2127 I2C touchscreen"
+ depends on I2C
+ help
+ Say Y here if you have an Elan eKTF2127 touchscreen
+ connected to your system.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the
+ module will be called ektf2127.
+
config TOUCHSCREEN_ELO
tristate "Elo serial touchscreens"
select SERIO
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 33b2eb8..db876ef 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_TOUCHSCREEN_HAMPSHIRE) += hampshire.o
obj-$(CONFIG_TOUCHSCREEN_GUNZE) += gunze.o
obj-$(CONFIG_TOUCHSCREEN_EETI) += eeti_ts.o
obj-$(CONFIG_TOUCHSCREEN_ELAN) += elants_i2c.o
+obj-$(CONFIG_TOUCHSCREEN_EKTF2127) += ektf2127.o
obj-$(CONFIG_TOUCHSCREEN_ELO) += elo.o
obj-$(CONFIG_TOUCHSCREEN_EGALAX) += egalax_ts.o
obj-$(CONFIG_TOUCHSCREEN_EGALAX_SERIAL) += egalax_ts_serial.o
diff --git a/drivers/input/touchscreen/ektf2127.c b/drivers/input/touchscreen/ektf2127.c
new file mode 100644
index 0000000..512a394
--- /dev/null
+++ b/drivers/input/touchscreen/ektf2127.c
@@ -0,0 +1,333 @@
+/*
+ * Driver for ELAN eKTF2127 i2c touchscreen controller
+ *
+ * For this driver the layout of the Chipone icn8318 i2c
+ * touchscreencontroller is used.
+ *
+ * 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.
+ *
+ * Author:
+ * Michel Verlaan <michel.verl at gmail.com>
+ * Siebren Vroegindeweij <siebren.vroegindeweij at hotmail.com>
+ *
+ * Original chipone_icn8318 driver:
+ * Hans de Goede <hdegoede at redhat.com>
+ */
+
+#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>
+#include <linux/of.h>
+#include <linux/delay.h>
+
+/* Packet header defines (first byte of data send / received) */
+#define EKTF2127_NOISE 0x40
+#define EKTF2127_RESPONSE 0x52
+#define EKTF2127_REQUEST 0x53
+#define EKTF2127_HELLO 0x55
+#define EKTF2127_REPORT 0x5d
+#define EKTF2127_CALIB_DONE 0x66
+
+/* Register deines (second byte of data send / received) */
+#define EKTF2127_ENV_NOISY 0x41
+#define EKTF2127_HEIGHT 0x60
+#define EKTF2127_WIDTH 0x63
+
+/* 2 bytes header + 5 * 3 bytes coordinates + 3 bytes pressure info + footer */
+#define EKTF2127_TOUCH_REPORT_SIZE 21
+#define EKTF2127_MAX_TOUCHES 5
+
+struct ektf2127_data {
+ struct i2c_client *client;
+ struct input_dev *input;
+ struct gpio_desc *power_gpios;
+ struct touchscreen_properties prop;
+};
+
+static void retrieve_coordinates(struct input_mt_pos *touches,
+ int touch_count, char *buf)
+{
+ int index = 0;
+ int i = 0;
+
+ for (i = 0; i < touch_count; i++) {
+ index = 2 + i * 3;
+
+ touches[i].x = (buf[index] & 0x0f);
+ touches[i].x <<= 8;
+ touches[i].x |= buf[index + 2];
+
+ touches[i].y = (buf[index] & 0xf0);
+ touches[i].y <<= 4;
+ touches[i].y |= buf[index + 1];
+ }
+}
+
+static irqreturn_t ektf2127_irq(int irq, void *dev_id)
+{
+ struct ektf2127_data *data = dev_id;
+ struct device *dev = &data->client->dev;
+ struct input_mt_pos touches[EKTF2127_MAX_TOUCHES];
+ int touch_count;
+ int slots[EKTF2127_MAX_TOUCHES];
+ char buff[EKTF2127_TOUCH_REPORT_SIZE];
+ int i, ret;
+
+ ret = i2c_master_recv(data->client, buff, EKTF2127_TOUCH_REPORT_SIZE);
+ if (ret != EKTF2127_TOUCH_REPORT_SIZE) {
+ dev_err(dev, "Error reading touch data\n");
+ return IRQ_HANDLED;
+ }
+
+ switch (buff[0]) {
+ case EKTF2127_REPORT:
+ /* Handled below */
+ break;
+ case EKTF2127_NOISE:
+ if (buff[1] == EKTF2127_ENV_NOISY)
+ dev_dbg(dev, "Environment is electically noisy\n");
+ return IRQ_HANDLED;
+ case EKTF2127_HELLO:
+ case EKTF2127_CALIB_DONE:
+ return IRQ_HANDLED;
+ default:
+ dev_err(dev, "Unexpected packet header byte %02x\n", buff[0]);
+ return IRQ_HANDLED;
+ }
+
+ touch_count = buff[1] & 0x07;
+
+ if (touch_count > EKTF2127_MAX_TOUCHES) {
+ dev_err(dev, "Too many touches %d > %d\n",
+ touch_count, EKTF2127_MAX_TOUCHES);
+ touch_count = EKTF2127_MAX_TOUCHES;
+ }
+
+ retrieve_coordinates(touches, touch_count, buff);
+ input_mt_assign_slots(data->input, slots, touches,
+ touch_count, 0);
+
+ for (i = 0; i < touch_count; i++) {
+ input_mt_slot(data->input, slots[i]);
+ input_mt_report_slot_state(data->input, MT_TOOL_FINGER, true);
+ touchscreen_report_pos(data->input, &data->prop, touches[i].x,
+ touches[i].y, true);
+ }
+
+ input_mt_sync_frame(data->input);
+ input_sync(data->input);
+
+ return IRQ_HANDLED;
+}
+
+static int ektf2127_start(struct input_dev *dev)
+{
+ struct ektf2127_data *data = input_get_drvdata(dev);
+
+ enable_irq(data->client->irq);
+ gpiod_set_value_cansleep(data->power_gpios, 1);
+
+ return 0;
+}
+
+static void ektf2127_stop(struct input_dev *dev)
+{
+ struct ektf2127_data *data = input_get_drvdata(dev);
+
+ disable_irq(data->client->irq);
+ gpiod_set_value_cansleep(data->power_gpios, 0);
+}
+
+static int ektf2127_suspend(struct device *dev)
+{
+ struct ektf2127_data *data = i2c_get_clientdata(to_i2c_client(dev));
+
+ mutex_lock(&data->input->mutex);
+ if (data->input->users)
+ ektf2127_stop(data->input);
+ mutex_unlock(&data->input->mutex);
+
+ return 0;
+}
+
+static int ektf2127_resume(struct device *dev)
+{
+ struct ektf2127_data *data = i2c_get_clientdata(to_i2c_client(dev));
+
+ mutex_lock(&data->input->mutex);
+ if (data->input->users)
+ ektf2127_start(data->input);
+ mutex_unlock(&data->input->mutex);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(ektf2127_pm_ops, ektf2127_suspend,
+ ektf2127_resume);
+
+static int ektf2127_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct ektf2127_data *data;
+ struct input_dev *input;
+ char buff[4];
+ int error, max_x, max_y, ret = 0;
+
+ 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;
+
+ /* This requests the gpio *and* turns on the touchscreen controller */
+ data->power_gpios = devm_gpiod_get(dev, "power", GPIOD_OUT_HIGH);
+ if (IS_ERR(data->power_gpios)) {
+ error = PTR_ERR(data->power_gpios);
+ if (error != -EPROBE_DEFER)
+ dev_err(dev, "Error getting power gpio: %d\n", error);
+ return error;
+ }
+
+ input = devm_input_allocate_device(dev);
+ if (!input)
+ return -ENOMEM;
+
+ input->name = client->name;
+ input->id.bustype = BUS_I2C;
+ input->open = ektf2127_start;
+ input->close = ektf2127_stop;
+
+ data->client = client;
+
+ /* Read hello (ignore result, depends on initial power state) */
+ msleep(20);
+ i2c_master_recv(data->client, buff, 4);
+
+ /* Read resolution from chip */
+
+ /* Request width */
+ buff[0] = EKTF2127_REQUEST;
+ buff[1] = EKTF2127_WIDTH;
+ buff[2] = 0x00;
+ buff[3] = 0x00;
+ ret = i2c_master_send(data->client, buff, 4);
+ if (ret != 4) {
+ dev_err(dev, "Error requesting width\n");
+ return ret < 0 ? ret : -EIO;
+ }
+
+ msleep(20);
+
+ /* Read response */
+ ret = i2c_master_recv(data->client, buff, 4);
+ if (ret != 4) {
+ dev_err(dev, "Error receiving width\n");
+ return ret < 0 ? ret : -EIO;
+ }
+
+ if ((buff[0] == EKTF2127_RESPONSE) && (buff[1] == EKTF2127_WIDTH)) {
+ max_x = (((buff[3] & 0xf0) << 4) | buff[2]) - 1;
+ } else {
+ dev_err(dev, "Error unexpected width data\n");
+ return -EIO;
+ }
+
+ /* Request height */
+ buff[0] = EKTF2127_REQUEST;
+ buff[1] = EKTF2127_HEIGHT;
+ buff[2] = 0x00;
+ buff[3] = 0x00;
+ ret = i2c_master_send(data->client, buff, 4);
+ if (ret != 4) {
+ dev_err(dev, "Error requesting height\n");
+ return ret < 0 ? ret : -EIO;
+ }
+
+ msleep(20);
+
+ /* Read response */
+ ret = i2c_master_recv(data->client, buff, 4);
+ if (ret != 4) {
+ dev_err(dev, "Error receiving height\n");
+ return ret < 0 ? ret : -EIO;
+ }
+
+ if ((buff[0] == EKTF2127_RESPONSE) && (buff[1] == EKTF2127_HEIGHT)) {
+ max_y = (((buff[3] & 0xf0) << 4) | buff[2]) - 1;
+ } else {
+ dev_err(dev, "Error unexpected height data\n");
+ return -EIO;
+ }
+
+ input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_x, 0, 0);
+ input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
+ touchscreen_parse_properties(input, true, &data->prop);
+
+ error = input_mt_init_slots(input, EKTF2127_MAX_TOUCHES,
+ INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED
+ | INPUT_MT_TRACK);
+ if (error)
+ return error;
+
+ data->input = input;
+ input_set_drvdata(input, data);
+
+ error = devm_request_threaded_irq(dev, client->irq, NULL, ektf2127_irq,
+ IRQF_ONESHOT, client->name, data);
+ if (error) {
+ dev_err(dev, "Error requesting irq: %d\n", error);
+ return error;
+ }
+
+ /* Stop device till opened */
+ ektf2127_stop(data->input);
+
+ error = input_register_device(input);
+ if (error)
+ return error;
+
+ i2c_set_clientdata(client, data);
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id ektf2127_of_match[] = {
+ { .compatible = "elan,ektf2127" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, ektf2127_of_match);
+#endif
+
+static const struct i2c_device_id ektf2127_i2c_id[] = {
+ { "ektf2127", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, ektf2127_i2c_id);
+
+static struct i2c_driver ektf2127_driver = {
+ .driver = {
+ .name = "elan_ektf2127",
+ .pm = &ektf2127_pm_ops,
+ .of_match_table = of_match_ptr(ektf2127_of_match),
+ },
+ .probe = ektf2127_probe,
+ .id_table = ektf2127_i2c_id,
+};
+
+module_i2c_driver(ektf2127_driver);
+
+MODULE_DESCRIPTION("ELAN eKTF2127 I2C Touchscreen Driver");
+MODULE_AUTHOR("Michel Verlaan, Siebren Vroegindeweij");
+MODULE_LICENSE("GPL");
--
2.9.3
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