[PATCH v5 2/2] Input: add support for the Samsung S6SY761 touchscreen

Andi Shyti
2017-11-02T06:07:41Z

The S6SY761 touchscreen is a capicitive multi-touch controller
for mobile use. It's connected with i2c at the address 0x48.

This commit provides a basic version of the driver which can
handle only initialization, touch events and power states.

The controller is controlled by a firmware which, in the version
I currently have, doesn't provide all the possible
functionalities mentioned in the datasheet.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
---
drivers/input/touchscreen/Kconfig | 11 +
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/s6sy761.c | 548 ++++++++++++++++++++++++++++++++++++
3 files changed, 560 insertions(+)
create mode 100644 drivers/input/touchscreen/s6sy761.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 64b30fe273fd..1405c08a529f 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -383,6 +383,17 @@ config TOUCHSCREEN_S3C2410
To compile this driver as a module, choose M here: the
module will be called s3c2410_ts.

+config TOUCHSCREEN_S6SY761
+ tristate "Samsung S6SY761 Touchscreen driver"
+ depends on I2C
+ help
+ Say Y if you have the Samsung S6SY761 driver
+
+ If unsure, say N
+
+ To compile this driver as module, choose M here: the
+ module will be called s6sy761.
+
config TOUCHSCREEN_GUNZE
tristate "Gunze AHL-51S touchscreen"
select SERIO
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 6badce87037b..4f63439211fd 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -64,6 +64,7 @@ obj-$(CONFIG_TOUCHSCREEN_PENMOUNT) += penmount.o
obj-$(CONFIG_TOUCHSCREEN_PIXCIR) += pixcir_i2c_ts.o
obj-$(CONFIG_TOUCHSCREEN_RM_TS) += raydium_i2c_ts.o
obj-$(CONFIG_TOUCHSCREEN_S3C2410) += s3c2410_ts.o
+obj-$(CONFIG_TOUCHSCREEN_S6SY761) += s6sy761.o
obj-$(CONFIG_TOUCHSCREEN_SILEAD) += silead.o
obj-$(CONFIG_TOUCHSCREEN_SIS_I2C) += sis_i2c.o
obj-$(CONFIG_TOUCHSCREEN_ST1232) += st1232.o
diff --git a/drivers/input/touchscreen/s6sy761.c b/drivers/input/touchscreen/s6sy761.c
new file mode 100644
index 000000000000..33097e7459df
--- /dev/null
+++ b/drivers/input/touchscreen/s6sy761.c
@@ -0,0 +1,548 @@
+/*
+ * Copyright (c) 2017 Samsung Electronics Co., Ltd.
+ * Author: Andi Shyti <andi.shyti@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Samsung S6SY761 Touchscreen device driver
+ */
+
+#include <asm/unaligned.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
+
+/* commands */
+#define S6SY761_SENSE_ON 0x10
+#define S6SY761_SENSE_OFF 0x11
+#define S6SY761_TOUCH_FUNCTION 0x30 /* R/W for get/set */
+#define S6SY761_FIRMWARE_INTEGRITY 0x21
+#define S6SY761_PANEL_ID 0x23
+#define S6SY761_DEVICE_ID 0x52
+#define S6SY761_BOOT_STATUS 0x55
+#define S6SY761_READ_ONE_EVENT 0x60
+#define S6SY761_READ_ALL_EVENT 0x61
+#define S6SY761_CLEAR_EVENT_STACK 0x62
+#define S6SY761_APPLICATION_MODE 0xe4
+
+/* events */
+#define S6SY761_EVENT_INFO 0x02
+#define S6SY761_EVENT_VENDOR_INFO 0x07
+
+/* info */
+#define S6SY761_INFO_BOOT_COMPLETE 0x00
+
+/* firmware status */
+#define S6SY761_FW_OK 0x80
+
+/*
+ * the functionalities are put as a reference
+ * as in the device I am using none of them
+ * works therefore not used in this driver yet.
+ */
+/* touchscreen functionalities */
+#define S6SY761_MASK_TOUCH BIT(0)
+#define S6SY761_MASK_HOVER BIT(1)
+#define S6SY761_MASK_COVER BIT(2)
+#define S6SY761_MASK_GLOVE BIT(3)
+#define S6SY761_MASK_STYLUS BIT(4)
+#define S6SY761_MASK_PALM BIT(5)
+#define S6SY761_MASK_WET BIT(6)
+#define S6SY761_MASK_PROXIMITY BIT(7)
+
+/* boot status (BS) */
+#define S6SY761_BS_BOOT_LOADER 0x10
+#define S6SY761_BS_APPLICATION 0x20
+
+/* event id */
+#define S6SY761_EVENT_ID_COORDINATE 0x00
+#define S6SY761_EVENT_ID_STATUS 0x01
+
+/* event register masks */
+#define S6SY761_MASK_TOUCH_STATE 0xc0 /* byte 0 */
+#define S6SY761_MASK_TID 0x3c
+#define S6SY761_MASK_EID 0x03
+#define S6SY761_MASK_X 0xf0 /* byte 3 */
+#define S6SY761_MASK_Y 0x0f
+#define S6SY761_MASK_Z 0x3f /* byte 6 */
+#define S6SY761_MASK_LEFT_EVENTS 0x3f /* byte 7 */
+#define S6SY761_MASK_TOUCH_TYPE 0xc0 /* MSB in byte 6, LSB in byte 7 */
+
+/* event touch state values */
+#define S6SY761_TS_NONE 0x00
+#define S6SY761_TS_PRESS 0x01
+#define S6SY761_TS_MOVE 0x02
+#define S6SY761_TS_RELEASE 0x03
+
+/* application modes */
+#define S6SY761_APP_NORMAL 0x0
+#define S6SY761_APP_LOW_POWER 0x1
+#define S6SY761_APP_TEST 0x2
+#define S6SY761_APP_FLASH 0x3
+#define S6SY761_APP_SLEEP 0x4
+
+#define S6SY761_EVENT_SIZE 8
+#define S6SY761_EVENT_COUNT 32
+#define S6SY761_ALL_EVENT (S6SY761_EVENT_SIZE * S6SY761_EVENT_COUNT)
+#define S6SY761_DEVID_SIZE 3
+#define S6SY761_PANEL_ID_SIZE 11
+#define S6SY761_TS_STATUS_SIZE 5
+#define S6SY761_MAX_FINGERS 10
+
+#define S6SY761_DEV_NAME "s6sy761"
+
+enum s6sy761_regulators {
+ S6SY761_REGULATOR_VDD,
+ S6SY761_REGULATOR_AVDD,
+};
+
+struct s6sy761_data {
+ struct i2c_client *client;
+ struct regulator_bulk_data regulators[2];
+ struct input_dev *input;
+ struct touchscreen_properties prop;
+
+ u8 data[S6SY761_ALL_EVENT];
+
+ u16 devid;
+ u8 tx_channel;
+};
+
+/*
+ * We can't simply use i2c_smbus_read_i2c_block_data because we
+ * need to read more than 255 bytes
+ */
+static int s6sy761_read_events(struct s6sy761_data *sdata, u16 n_events)
+{
+ u8 cmd = S6SY761_READ_ALL_EVENT;
+ struct i2c_msg msgs[2] = {
+ {
+ .addr = sdata->client->addr,
+ .len = 1,
+ .buf = &cmd,
+ },
+ {
+ .addr = sdata->client->addr,
+ .flags = I2C_M_RD,
+ .len = (n_events * S6SY761_EVENT_SIZE),
+ .buf = sdata->data + S6SY761_EVENT_SIZE,
+ },
+ };
+ int ret;
+
+ ret = i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
+ if (ret < 0)
+ return ret;
+
+ return ret == ARRAY_SIZE(msgs) ? 0 : -EIO;
+}
+
+static void s6sy761_report_coordinates(struct s6sy761_data *sdata,
+ u8 *event, u8 tid)
+{
+ u8 major = event[4];
+ u8 minor = event[5];
+ u8 z = event[6] & S6SY761_MASK_Z;
+ u16 x = (event[1] << 3) | ((event[3] & S6SY761_MASK_X) >> 4);
+ u16 y = (event[2] << 3) | (event[3] & S6SY761_MASK_Y);
+
+ input_mt_slot(sdata->input, tid);
+
+ input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, true);
+ input_report_abs(sdata->input, ABS_MT_POSITION_X, x);
+ input_report_abs(sdata->input, ABS_MT_POSITION_Y, y);
+ input_report_abs(sdata->input, ABS_MT_TOUCH_MAJOR, major);
+ input_report_abs(sdata->input, ABS_MT_TOUCH_MINOR, minor);
+ input_report_abs(sdata->input, ABS_MT_PRESSURE, z);
+
+ input_sync(sdata->input);
+}
+
+static void s6sy761_report_release(struct s6sy761_data *sdata,
+ u8 *event, u8 tid)
+{
+ input_mt_slot(sdata->input, tid);
+ input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, false);
+
+ input_sync(sdata->input);
+}
+
+static void s6sy761_handle_coordinates(struct s6sy761_data *sdata, u8 *event)
+{
+ u8 tid;
+ u8 touch_state;
+
+ if (unlikely(!(event[0] & S6SY761_MASK_TID)))
+ return;
+
+ tid = ((event[0] & S6SY761_MASK_TID) >> 2) - 1;
+ touch_state = (event[0] & S6SY761_MASK_TOUCH_STATE) >> 6;
+
+ switch (touch_state) {
+
+ case S6SY761_TS_NONE:
+ break;
+ case S6SY761_TS_RELEASE:
+ s6sy761_report_release(sdata, event, tid);
+ break;
+ case S6SY761_TS_PRESS:
+ case S6SY761_TS_MOVE:
+ s6sy761_report_coordinates(sdata, event, tid);
+ break;
+ }
+}
+
+static void s6sy761_handle_events(struct s6sy761_data *sdata, u8 n_events)
+{
+ int i;
+
+ for (i = 0; i < n_events; i++) {
+ u8 *event = &sdata->data[i * S6SY761_EVENT_SIZE];
+ u8 event_id = event[0] & S6SY761_MASK_EID;
+
+ if (!event[0])
+ return;
+
+ switch (event_id) {
+
+ case S6SY761_EVENT_ID_COORDINATE:
+ s6sy761_handle_coordinates(sdata, event);
+ break;
+
+ case S6SY761_EVENT_ID_STATUS:
+ break;
+
+ default:
+ break;
+ }
+ }
+}
+
+static irqreturn_t s6sy761_irq_handler(int irq, void *dev)
+{
+ struct s6sy761_data *sdata = dev;
+ int ret;
+ u8 n_events;
+
+ ret = i2c_smbus_read_i2c_block_data(sdata->client,
+ S6SY761_READ_ONE_EVENT,
+ S6SY761_EVENT_SIZE,
+ sdata->data);
+ if (ret < 0) {
+ dev_err(&sdata->client->dev, "failed to read events\n");
+ return IRQ_HANDLED;
+ }
+
+ if (!sdata->data[0])
+ return IRQ_HANDLED;
+
+ n_events = sdata->data[7] & S6SY761_MASK_LEFT_EVENTS;
+ if (unlikely(n_events > S6SY761_EVENT_COUNT - 1))
+ return IRQ_HANDLED;
+
+ if (n_events) {
+ ret = s6sy761_read_events(sdata, n_events);
+ if (ret < 0) {
+ dev_err(&sdata->client->dev, "failed to read events\n");
+ return IRQ_HANDLED;
+ }
+ }
+
+ s6sy761_handle_events(sdata, n_events + 1);
+
+ return IRQ_HANDLED;
+}
+
+static int s6sy761_input_open(struct input_dev *dev)
+{
+ struct s6sy761_data *sdata = input_get_drvdata(dev);
+
+ return i2c_smbus_write_byte(sdata->client, S6SY761_SENSE_ON);
+}
+
+static void s6sy761_input_close(struct input_dev *dev)
+{
+ struct s6sy761_data *sdata = input_get_drvdata(dev);
+ int ret;
+
+ ret = i2c_smbus_write_byte(sdata->client, S6SY761_SENSE_OFF);
+ if (ret)
+ dev_err(&sdata->client->dev, "failed to turn off sensing\n");
+}
+
+static ssize_t s6sy761_sysfs_devid(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct s6sy761_data *sdata = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%#x\n", sdata->devid);
+}
+
+static DEVICE_ATTR(devid, 0444, s6sy761_sysfs_devid, NULL);
+
+static struct attribute *s6sy761_sysfs_attrs[] = {
+ &dev_attr_devid.attr,
+ NULL
+};
+
+static struct attribute_group s6sy761_attribute_group = {
+ .attrs = s6sy761_sysfs_attrs
+};
+
+static int s6sy761_hw_init(struct s6sy761_data *sdata)
+{
+ u8 buffer[S6SY761_PANEL_ID_SIZE]; /* larger read size */
+ u8 event;
+ int ret;
+
+ ret = regulator_bulk_enable(ARRAY_SIZE(sdata->regulators),
+ sdata->regulators);
+ if (ret)
+ return ret;
+
+ msleep(140);
+
+ ret = i2c_smbus_read_i2c_block_data(sdata->client,
+ S6SY761_READ_ONE_EVENT,
+ S6SY761_EVENT_SIZE,
+ buffer);
+ if (ret < 0)
+ return ret;
+
+ event = (buffer[0] >> 2) & 0xf;
+
+ if ((event != S6SY761_EVENT_INFO &&
+ event != S6SY761_EVENT_VENDOR_INFO) ||
+ buffer[1] != S6SY761_INFO_BOOT_COMPLETE)
+ return -ENODEV;
+
+ ret = i2c_smbus_read_i2c_block_data(sdata->client,
+ S6SY761_DEVICE_ID,
+ S6SY761_DEVID_SIZE,
+ buffer);
+ if (ret < 0)
+ return ret;
+
+ sdata->devid = get_unaligned_be16(buffer + 1);
+
+ ret = i2c_smbus_read_i2c_block_data(sdata->client,
+ S6SY761_PANEL_ID,
+ S6SY761_PANEL_ID_SIZE,
+ buffer);
+ if (ret < 0)
+ return ret;
+
+ sdata->prop.max_x = get_unaligned_be16(buffer);
+ sdata->prop.max_y = get_unaligned_be16(buffer + 2);
+
+ /* if no tx channels defined, at least keep one */
+ sdata->tx_channel = max_t(u8, buffer[8], 1);
+
+ ret = i2c_smbus_read_byte_data(sdata->client,
+ S6SY761_FIRMWARE_INTEGRITY);
+ if (ret < 0)
+ return ret;
+ else if (ret != S6SY761_FW_OK)
+ return -ENODEV;
+
+ ret = i2c_smbus_read_byte_data(sdata->client, S6SY761_BOOT_STATUS);
+ if (ret < 0)
+ return ret;
+
+ /* for some reasons the device might be stuck in the bootloader */
+ if (ret != S6SY761_BS_APPLICATION)
+ return -ENODEV;
+
+ /* enable touch functionality */
+ ret = i2c_smbus_write_word_data(sdata->client,
+ S6SY761_TOUCH_FUNCTION,
+ S6SY761_MASK_TOUCH);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static void s6sy761_power_off(void *data)
+{
+ struct s6sy761_data *sdata = data;
+
+ disable_irq(sdata->client->irq);
+ regulator_bulk_disable(ARRAY_SIZE(sdata->regulators),
+ sdata->regulators);
+}
+
+static int s6sy761_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct s6sy761_data *sdata;
+ int err;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
+ I2C_FUNC_SMBUS_BYTE_DATA |
+ I2C_FUNC_SMBUS_I2C_BLOCK))
+ return -ENODEV;
+
+ sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL);
+ if (!sdata)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, sdata);
+ sdata->client = client;
+
+ sdata->regulators[S6SY761_REGULATOR_VDD].supply = "vdd";
+ sdata->regulators[S6SY761_REGULATOR_AVDD].supply = "avdd";
+ err = devm_regulator_bulk_get(&client->dev,
+ ARRAY_SIZE(sdata->regulators),
+ sdata->regulators);
+ if (err)
+ return err;
+
+ err = devm_add_action_or_reset(&client->dev, s6sy761_power_off, sdata);
+ if (err)
+ return err;
+
+ err = s6sy761_hw_init(sdata);
+ if (err)
+ return err;
+
+ sdata->input = devm_input_allocate_device(&client->dev);
+ if (!sdata->input)
+ return -ENOMEM;
+
+ sdata->input->name = S6SY761_DEV_NAME;
+ sdata->input->id.bustype = BUS_I2C;
+ sdata->input->open = s6sy761_input_open;
+ sdata->input->close = s6sy761_input_close;
+
+ /* the range has been previously read in hw_init */
+ if (sdata->prop.max_x && sdata->prop.max_y) {
+ input_set_abs_params(sdata->input, ABS_MT_POSITION_X, 0,
+ sdata->prop.max_x, 0, 0);
+ input_set_abs_params(sdata->input, ABS_MT_POSITION_Y, 0,
+ sdata->prop.max_y, 0, 0);
+ } else {
+ input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_X);
+ input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_Y);
+ }
+
+ input_set_abs_params(sdata->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
+ input_set_abs_params(sdata->input, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0);
+ /* the pressure is represented in 6 bits */
+ input_set_abs_params(sdata->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
+
+ touchscreen_parse_properties(sdata->input, true, &sdata->prop);
+
+ err = input_mt_init_slots(sdata->input,
+ sdata->tx_channel,
+ INPUT_MT_DIRECT);
+ if (err)
+ return err;
+
+ input_set_drvdata(sdata->input, sdata);
+
+ err = input_register_device(sdata->input);
+ if (err)
+ return err;
+
+ err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+ s6sy761_irq_handler,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ "s6sy761_irq", sdata);
+ if (err)
+ return err;
+
+ err = devm_device_add_group(&client->dev, &s6sy761_attribute_group);
+ if (err)
+ return err;
+
+ pm_runtime_enable(&client->dev);
+
+ return 0;
+}
+
+static int s6sy761_remove(struct i2c_client *client)
+{
+ pm_runtime_disable(&client->dev);
+
+ return 0;
+}
+
+static int __maybe_unused s6sy761_runtime_suspend(struct device *dev)
+{
+ struct s6sy761_data *sdata = dev_get_drvdata(dev);
+
+ return i2c_smbus_write_byte_data(sdata->client,
+ S6SY761_APPLICATION_MODE, S6SY761_APP_SLEEP);
+}
+
+static int __maybe_unused s6sy761_runtime_resume(struct device *dev)
+{
+ struct s6sy761_data *sdata = dev_get_drvdata(dev);
+
+ return i2c_smbus_write_byte_data(sdata->client,
+ S6SY761_APPLICATION_MODE, S6SY761_APP_NORMAL);
+}
+
+static int __maybe_unused s6sy761_suspend(struct device *dev)
+{
+ struct s6sy761_data *sdata = dev_get_drvdata(dev);
+
+ s6sy761_power_off(sdata);
+
+ return 0;
+}
+
+static int __maybe_unused s6sy761_resume(struct device *dev)
+{
+ struct s6sy761_data *sdata = dev_get_drvdata(dev);
+
+ enable_irq(sdata->client->irq);
+
+ return s6sy761_hw_init(sdata);
+}
+
+static const struct dev_pm_ops s6sy761_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(s6sy761_suspend, s6sy761_resume)
+ SET_RUNTIME_PM_OPS(s6sy761_runtime_suspend,
+ s6sy761_runtime_resume, NULL)
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id s6sy761_of_match[] = {
+ { .compatible = "samsung,s6sy761", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, s6sy761_of_match);
+#endif
+
+static const struct i2c_device_id s6sy761_id[] = {
+ { "s6sy761", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, s6sy761_id);
+
+static struct i2c_driver s6sy761_driver = {
+ .driver = {
+ .name = S6SY761_DEV_NAME,
+ .of_match_table = of_match_ptr(s6sy761_of_match),
+ .pm = &s6sy761_pm_ops,
+ },
+ .probe = s6sy761_probe,
+ .remove = s6sy761_remove,
+ .id_table = s6sy761_id,
+};
+
+module_i2c_driver(s6sy761_driver);
+
+MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
+MODULE_DESCRIPTION("Samsung S6SY761 Touch Screen");
+MODULE_LICENSE("GPL v2");
--
2.14.2