Re: [linux-sunxi] [PATCH 3/5] Input: add driver for Ilitek ili2139 touch IC

From: Hans de Goede
Date: Tue Oct 11 2016 - 05:44:08 EST


Hi,

On 10/11/2016 02:33 AM, Icenowy Zheng wrote:
This driver adds support for Ilitek ili2139 touch IC, which is used in
several Colorfly tablets (for example, Colorfly E708 Q1, which is an
Allwinner A31s tablet with mainline kernel support).

Theortically it may support more Ilitek touch ICs, however, only ili2139
is used in any mainlined device.

It supports device tree enumeration, with screen resolution and axis
quirks configurable.

Signed-off-by: Icenowy Zheng <icenowy@xxxxxxxx>
---
drivers/input/touchscreen/Kconfig | 14 ++
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/ili2139.c | 320 ++++++++++++++++++++++++++++++++++++
3 files changed, 335 insertions(+)
create mode 100644 drivers/input/touchscreen/ili2139.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 5079813..bb4d9d2 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -348,6 +348,20 @@ config TOUCHSCREEN_ILI210X
To compile this driver as a module, choose M here: the
module will be called ili210x.

+config TOUCHSCREEN_ILI2139
+ tristate "Ilitek ILI2139 based touchscreen"
+ depends on I2C
+ depends on OF
+ help
+ Say Y here if you have a ILI2139 based touchscreen
+ controller. Such kind of chipsets can be found in several
+ Colorfly tablets.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here; the
+ module will be called ili2139.
+
config TOUCHSCREEN_IPROC
tristate "IPROC touch panel driver support"
depends on ARCH_BCM_IPROC || COMPILE_TEST
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 81b8645..930b5e2 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_TOUCHSCREEN_EGALAX_SERIAL) += egalax_ts_serial.o
obj-$(CONFIG_TOUCHSCREEN_FUJITSU) += fujitsu_ts.o
obj-$(CONFIG_TOUCHSCREEN_GOODIX) += goodix.o
obj-$(CONFIG_TOUCHSCREEN_ILI210X) += ili210x.o
+obj-$(CONFIG_TOUCHSCREEN_ILI2139) += ili2139.o
obj-$(CONFIG_TOUCHSCREEN_IMX6UL_TSC) += imx6ul_tsc.o
obj-$(CONFIG_TOUCHSCREEN_INEXIO) += inexio.o
obj-$(CONFIG_TOUCHSCREEN_INTEL_MID) += intel-mid-touch.o
diff --git a/drivers/input/touchscreen/ili2139.c b/drivers/input/touchscreen/ili2139.c
new file mode 100644
index 0000000..65c2dea
--- /dev/null
+++ b/drivers/input/touchscreen/ili2139.c
@@ -0,0 +1,320 @@
+/* -------------------------------------------------------------------------
+ * Copyright (C) 2016, Icenowy Zheng <icenowy@xxxxxxxx>
+ *
+ * Derived from:
+ * ili210x.c
+ * Copyright (C) Olivier Sobrie <olivier@xxxxxxxxx>
+ *
+ * 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/module.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/delay.h>
+#include <linux/workqueue.h>
+
+#define DEFAULT_POLL_PERIOD 20
+
+#define MAX_TOUCHES 10
+#define COMPATIBLE_TOUCHES 2
+
+/* Touchscreen commands */
+#define REG_TOUCHDATA 0x10
+#define REG_TOUCHSUBDATA 0x11
+#define REG_PANEL_INFO 0x20
+#define REG_FIRMWARE_VERSION 0x40
+#define REG_PROTO_VERSION 0x42
+
+#define SUBDATA_STATUS_TOUCH_POINT 0x80
+#define SUBDATA_STATUS_RELEASE_POINT 0x00
+
+struct finger {
+ u8 x_low;
+ u8 x_high;
+ u8 y_low;
+ u8 y_high;
+} __packed;
+
+struct touchdata {
+ u8 length;
+ struct finger finger[COMPATIBLE_TOUCHES];
+} __packed;
+
+struct touch_subdata {
+ u8 status;
+ struct finger finger;
+} __packed;
+
+struct panel_info {
+ struct finger finger_max;
+ u8 xchannel_num;
+ u8 ychannel_num;
+} __packed;
+
+struct firmware_version {
+ u8 id;
+ u8 major;
+ u8 minor;
+} __packed;
+
+struct ili2139 {
+ struct i2c_client *client;
+ struct input_dev *input;
+ unsigned int poll_period;
+ struct delayed_work dwork;
+ struct touchscreen_properties prop;
+ int slots[MAX_TOUCHES];
+ int ids[MAX_TOUCHES];
+ struct input_mt_pos pos[MAX_TOUCHES];
+};
+
+static int ili2139_read_reg(struct i2c_client *client, u8 reg, void *buf,
+ size_t len)
+{
+ struct i2c_msg msg[2] = {
+ {
+ .addr = client->addr,
+ .flags = 0,
+ .len = 1,
+ .buf = &reg,
+ },
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = len,
+ .buf = buf,
+ }
+ };
+
+ if (i2c_transfer(client->adapter, msg, 2) != 2) {
+ dev_err(&client->dev, "i2c transfer failed\n");
+ return -EIO;
+ }
+
+ return 0;
+}

This just i2c_smbus_read_i2c_block_data, please use that instead.

+static void ili2139_work(struct work_struct *work)
+{
+ int id;
+ struct ili2139 *priv = container_of(work, struct ili2139,
+ dwork.work);
+ struct i2c_client *client = priv->client;
+ struct touchdata touchdata;
+ struct touch_subdata subdata;
+ int error;
+
+ error = ili2139_read_reg(client, REG_TOUCHDATA,
+ &touchdata, sizeof(touchdata));
+ if (error) {
+ dev_err(&client->dev,
+ "Unable to get touchdata, err = %d\n", error);
+ return;
+ }
+
+ for (id = 0; id < touchdata.length; id++) {
+ error = ili2139_read_reg(client, REG_TOUCHSUBDATA, &subdata,
+ sizeof(subdata));
+ if (error) {
+ dev_err(&client->dev,
+ "Unable to get touch subdata, err = %d\n",
+ error);
+ return;
+ }
+
+ priv->ids[id] = subdata.status & 0x3F;
+
+ /* The sequence changed in the v2 subdata protocol. */
+ touchscreen_set_mt_pos(&priv->pos[id], &priv->prop,
+ (subdata.finger.x_high | (subdata.finger.x_low << 8)),
+ (subdata.finger.y_high | (subdata.finger.y_low << 8)));
+ }
+
+ input_mt_assign_slots(priv->input, priv->slots, priv->pos,
+ touchdata.length, 0);
+
+ for (id = 0; id < touchdata.length; id++) {
+ input_mt_slot(priv->input, priv->slots[id]);
+ input_mt_report_slot_state(priv->input, MT_TOOL_FINGER,
+ subdata.status &
+ SUBDATA_STATUS_TOUCH_POINT);
+ input_report_abs(priv->input, ABS_MT_POSITION_X,
+ priv->pos[id].x);
+ input_report_abs(priv->input, ABS_MT_POSITION_Y,
+ priv->pos[id].y);
+ }
+
+ input_mt_sync_frame(priv->input);
+ input_sync(priv->input);
+
+ schedule_delayed_work(&priv->dwork,
+ msecs_to_jiffies(priv->poll_period));

If the irq is working properly there should be no need for this,
can you try with this schedule call removed ?

+}
+
+static irqreturn_t ili2139_irq(int irq, void *irq_data)
+{
+ struct ili2139 *priv = irq_data;
+
+ schedule_delayed_work(&priv->dwork, 0);
+
+ return IRQ_HANDLED;
+}
+
+static int ili2139_i2c_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct ili2139 *priv;
+ struct input_dev *input;
+ struct panel_info panel;
+ struct firmware_version firmware;
+ int xmax, ymax;
+ int error;
+
+ dev_dbg(dev, "Probing for ILI2139 I2C Touschreen driver");
+
+ if (client->irq <= 0) {
+ dev_err(dev, "No IRQ!\n");
+ return -ENODEV;
+ }
+
+ /* Get firmware version */
+ error = ili2139_read_reg(client, REG_FIRMWARE_VERSION,
+ &firmware, sizeof(firmware));
+ if (error) {
+ dev_err(dev, "Failed to get firmware version, err: %d\n",
+ error);
+ return error;
+ }
+
+ /* get panel info */
+ error = ili2139_read_reg(client, REG_PANEL_INFO, &panel, sizeof(panel));
+ if (error) {
+ dev_err(dev, "Failed to get panel information, err: %d\n",
+ error);
+ return error;
+ }
+
+ xmax = panel.finger_max.x_low | (panel.finger_max.x_high << 8);
+ ymax = panel.finger_max.y_low | (panel.finger_max.y_high << 8);
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ input = devm_input_allocate_device(dev);
+ if (!priv || !input)
+ return -ENOMEM;
+
+ priv->client = client;
+ priv->input = input;
+ priv->poll_period = DEFAULT_POLL_PERIOD;
+ INIT_DELAYED_WORK(&priv->dwork, ili2139_work);
+
+ /* Setup input device */
+ input->name = "ILI2139 Touchscreen";
+ input->id.bustype = BUS_I2C;
+ input->dev.parent = dev;
+
+ __set_bit(EV_SYN, input->evbit);
+ __set_bit(EV_KEY, input->evbit);
+ __set_bit(EV_ABS, input->evbit);
+
+ /* Multi touch */
+ input_mt_init_slots(input, MAX_TOUCHES, INPUT_MT_DIRECT |
+ INPUT_MT_DROP_UNUSED | INPUT_MT_TRACK);
+ input_set_abs_params(input, ABS_MT_POSITION_X, 0, xmax, 0, 0);
+ input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ymax, 0, 0);
+
+ touchscreen_parse_properties(input, true, &priv->prop);
+
+ input_set_drvdata(input, priv);
+ i2c_set_clientdata(client, priv);
+
+ error = devm_request_irq(dev, client->irq, ili2139_irq,
+ IRQF_TRIGGER_FALLING, client->name, priv);

If things work with the re-scheduleing of the delayed work
from the work removed, then you can use request_threaded_irq here,
pass in ili2139_irq as the threaded handler (and NULL as the non threaded
handler) and do all the i2c reading directly in ili2139_irq without needing
to use any work struct at all.

Regards,

Hans


+ if (error) {
+ dev_err(dev, "Unable to request touchscreen IRQ, err: %d\n",
+ error);
+ return error;
+ }
+
+ error = input_register_device(priv->input);
+ if (error) {
+ dev_err(dev, "Cannot register input device, err: %d\n", error);
+ return error;
+ }
+
+ device_init_wakeup(&client->dev, 1);
+
+ dev_dbg(dev,
+ "ILI2139 initialized (IRQ: %d), firmware version %d.%d.%d",
+ client->irq, firmware.id, firmware.major, firmware.minor);
+
+ return 0;
+}
+
+static int ili2139_i2c_remove(struct i2c_client *client)
+{
+ struct ili2139 *priv = i2c_get_clientdata(client);
+
+ cancel_delayed_work_sync(&priv->dwork);
+
+ return 0;
+}
+
+static int __maybe_unused ili2139_i2c_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+
+ if (device_may_wakeup(&client->dev))
+ enable_irq_wake(client->irq);
+
+ return 0;
+}
+
+static int __maybe_unused ili2139_i2c_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+
+ if (device_may_wakeup(&client->dev))
+ disable_irq_wake(client->irq);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(ili2139_i2c_pm,
+ ili2139_i2c_suspend, ili2139_i2c_resume);
+
+static const struct i2c_device_id ili2139_i2c_id[] = {
+ { "ili2139", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ili2139_i2c_id);
+
+static struct i2c_driver ili2139_ts_driver = {
+ .driver = {
+ .name = "ili2139_i2c",
+ .pm = &ili2139_i2c_pm,
+ },
+ .id_table = ili2139_i2c_id,
+ .probe = ili2139_i2c_probe,
+ .remove = ili2139_i2c_remove,
+};
+
+module_i2c_driver(ili2139_ts_driver);
+
+MODULE_AUTHOR("Olivier Sobrie <olivier@xxxxxxxxx>");
+MODULE_DESCRIPTION("ILI2139 I2C Touchscreen Driver");
+MODULE_LICENSE("GPL");