[RFC PATCH 0/2] Input: add fts2ba61y touchscreen driver

[RFC PATCH 0/2] Input: add fts2ba61y touchscreen driver

[Eric Gonçalves]

This patchset adds support for the ST-Microelectronics FTS2BA61Y,
a capacitive multi-touch touchscreen controller. this touchscreen
is used in many mobile devices, like ones from the Galaxy S22 series
and the Z Fold 5. Ivaylo Ivanov wrote the driver originally,
and I'm upstreaming it on his behalf.

Thanks!

Eric Gonçalves (2):
  dt-bindings: input: add ST-Microelectronics FTS2BA61Y touchscreen
    binding
  Input: add support for the STM FTS2BA61Y touchscreen

 .../input/touchscreen/st,fts2ba61y.yaml       |  52 ++
 drivers/input/touchscreen/Kconfig             |  11 +
 drivers/input/touchscreen/Makefile            |   1 +
 drivers/input/touchscreen/fts2ba61y.c         | 588 ++++++++++++++++++
 4 files changed, 652 insertions(+)
 create mode 100755 Documentation/devicetree/bindings/input/touchscreen/st,fts2ba61y.yaml
 create mode 100644 drivers/input/touchscreen/fts2ba61y.c

-- 
2.50.1

[RFC PATCH 1/2] dt-bindings: input: add ST-Microelectronics FTS2BA61Y touchscreen binding

[Eric Gonçalves]

Add the bindings for ST-Microelectronics FTS2BA61Y capacitive touchscreen.

Signed-off-by: Eric Gonçalves <ghatto404@gmail.com>
---
 .../input/touchscreen/st,fts2ba61y.yaml       | 52 +++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100755 Documentation/devicetree/bindings/input/touchscreen/st,fts2ba61y.yaml

diff --git a/Documentation/devicetree/bindings/input/touchscreen/st,fts2ba61y.yaml b/Documentation/devicetree/bindings/input/touchscreen/st,fts2ba61y.yaml
new file mode 100644
index 000000000000..e4d076bc7bcd
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/st,fts2ba61y.yaml
@@ -0,0 +1,52 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/touchscreen/st,fts2ba61y.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ST-Microelectronics FTS2BA61Y touchscreen controller
+
+maintainers:
+  - Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>
+
+allOf:
+  - $ref: touchscreen.yaml#
+
+properties:
+  compatible:
+    const: st,fts2ba61y
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  avdd-supply: true
+  vdd-supply: true
+
+unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - avdd-supply
+  - vdd-supply
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        touchscreen@0 {
+            compatible = "st,fts2ba61y";
+            reg = <0x0>;
+            interrupt-parent = <&gpa2>;
+            interrupts = <2 IRQ_TYPE_LEVEL_HIGH>;
+            avdd-supply = <&ldo17_reg>;
+            vdd-supply = <&ldo28_reg>;
+        };
+    };
-- 
2.50.1

[RFC PATCH 2/2] Input: add support for the STM FTS2BA61Y touchscreen

[Eric Gonçalves]

The ST-Microelectronics FTS2BA61Y touchscreen is a capacitive multi-touch
controller connected through SPI at 0x0, the touchscreen is typically
used in mobile devices (like the Galaxy S22 series)

Signed-off-by: Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>
Signed-off-by: Eric Gonçalves <ghatto404@gmail.com>
---
Ivaylo Ivanov originally wrote the FTS2BA61Y driver, I am upstreaming it
on his behalf.
---
 drivers/input/touchscreen/Kconfig     |  11 +
 drivers/input/touchscreen/Makefile    |   1 +
 drivers/input/touchscreen/fts2ba61y.c | 588 ++++++++++++++++++++++++++
 3 files changed, 600 insertions(+)
 create mode 100644 drivers/input/touchscreen/fts2ba61y.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 196905162945..1e199191f527 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -370,6 +370,17 @@ config TOUCHSCREEN_EXC3000
 	  To compile this driver as a module, choose M here: the
 	  module will be called exc3000.
 
+config TOUCHSCREEN_FTS2BA61Y
+	tristate "ST-Microelectronics FTS2BA61Y touchscreen"
+	depends on SPI
+	help
+	  Say Y here if you have the ST-Microelectronics FTS2BA61Y touchscreen
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called fts2ba61y.
+
 config TOUCHSCREEN_FUJITSU
 	tristate "Fujitsu serial touchscreen"
 	select SERIO
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 97a025c6a377..408a9fd5bd35 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_TOUCHSCREEN_ELO)		+= elo.o
 obj-$(CONFIG_TOUCHSCREEN_EGALAX)	+= egalax_ts.o
 obj-$(CONFIG_TOUCHSCREEN_EGALAX_SERIAL)	+= egalax_ts_serial.o
 obj-$(CONFIG_TOUCHSCREEN_EXC3000)	+= exc3000.o
+obj-$(CONFIG_TOUCHSCREEN_FTS2BA61Y)	+= fts2ba61y.o
 obj-$(CONFIG_TOUCHSCREEN_FUJITSU)	+= fujitsu_ts.o
 obj-$(CONFIG_TOUCHSCREEN_GOODIX)	+= goodix_ts.o
 obj-$(CONFIG_TOUCHSCREEN_GOODIX_BERLIN_CORE)	+= goodix_berlin_core.o
diff --git a/drivers/input/touchscreen/fts2ba61y.c b/drivers/input/touchscreen/fts2ba61y.c
new file mode 100644
index 000000000000..b3b3abca5404
--- /dev/null
+++ b/drivers/input/touchscreen/fts2ba61y.c
@@ -0,0 +1,588 @@
+// SPDX-License-Identifier: GPL-2.0
+// Based loosely on s6sy761.c
+
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/input/mt.h>
+#include <linux/spi/spi.h>
+#include <linux/input/touchscreen.h>
+#include <linux/unaligned.h>
+#include <linux/regulator/consumer.h>
+
+/* commands */
+#define FTS2BA61Y_CMD_SENSE_ON			0x10
+#define FTS2BA61Y_CMD_SENSE_OFF			0x11
+#define FTS2BA61Y_CMD_READ_PANEL_INFO		0x23
+#define FTS2BA61Y_CMD_READ_FW_VER		0x24
+#define FTS2BA61Y_CMD_TOUCHTYPE			0x30 /* R/W for get/set */
+#define FTS2BA61Y_CMD_CLEAR_EVENTS		0x62
+#define FTS2BA61Y_CMD_READ_EVENT		0x87
+#define FTS2BA61Y_CMD_CUSTOM_W			0xC0
+#define FTS2BA61Y_CMD_CUSTOM_R			0xD1
+#define FTS2BA61Y_CMD_REG_W			0xFA
+#define FTS2BA61Y_CMD_REG_R			0xFB
+
+/* touch type masks */
+#define FTS2BA61Y_MASK_TOUCH			BIT(0)
+#define FTS2BA61Y_MASK_HOVER			BIT(1)
+#define FTS2BA61Y_MASK_COVER			BIT(2)
+#define FTS2BA61Y_MASK_GLOVE			BIT(3)
+#define FTS2BA61Y_MASK_STYLUS			BIT(4)
+#define FTS2BA61Y_MASK_PALM			BIT(5)
+#define FTS2BA61Y_MASK_WET			BIT(6)
+#define FTS2BA61Y_TOUCHTYPE_DEFAULT		(FTS2BA61Y_MASK_TOUCH | \
+						 FTS2BA61Y_MASK_PALM | \
+						 FTS2BA61Y_MASK_WET)
+
+/* event status masks */
+#define FTS2BA61Y_MASK_STYPE			GENMASK(5, 2)
+#define FTS2BA61Y_MASK_EVENT_ID			GENMASK(1, 0)
+
+/* event coordinate masks */
+#define FTS2BA61Y_MASK_TCHSTA			GENMASK(7, 6)
+#define FTS2BA61Y_MASK_TID			GENMASK(5, 2)
+#define FTS2BA61Y_MASK_X_3_0			GENMASK(7, 4)
+#define FTS2BA61Y_MASK_Y_3_0			GENMASK(3, 0)
+#define FTS2BA61Y_MASK_Z			GENMASK(5, 0)
+#define FTS2BA61Y_MASK_TTYPE_3_2		GENMASK(7, 6)
+#define FTS2BA61Y_MASK_TTYPE_1_0		GENMASK(1, 0)
+#define FTS2BA61Y_MASK_LEFT_EVENTS		GENMASK(4, 0)
+
+/* event error status */
+#define FTS2BA61Y_EVENT_STATUSTYPE_INFO		0x2
+
+/* information report */
+#define FTS2BA61Y_INFO_READY_STATUS		0x0
+
+/* event status */
+#define FTS2BA61Y_COORDINATE_EVENT		0x0
+
+/* touch types */
+#define FTS2BA61Y_TOUCHTYPE_NORMAL		0x0
+#define FTS2BA61Y_TOUCHTYPE_HOVER		0x1
+#define FTS2BA61Y_TOUCHTYPE_FLIPCOVER		0x2
+#define FTS2BA61Y_TOUCHTYPE_GLOVE		0x3
+#define FTS2BA61Y_TOUCHTYPE_STYLUS		0x4
+#define FTS2BA61Y_TOUCHTYPE_PALM		0x5
+#define FTS2BA61Y_TOUCHTYPE_WET			0x6
+#define FTS2BA61Y_TOUCHTYPE_PROXIMITY		0x7
+#define FTS2BA61Y_TOUCHTYPE_JIG			0x8
+
+#define FTS2BA61Y_COORDINATE_ACTION_NONE	0x0
+#define FTS2BA61Y_COORDINATE_ACTION_PRESS	0x1
+#define FTS2BA61Y_COORDINATE_ACTION_MOVE	0x2
+#define FTS2BA61Y_COORDINATE_ACTION_RELEASE	0x3
+
+#define FTS2BA61Y_DEV_NAME			"fts2ba61y"
+#define FTS2BA61Y_EVENT_BUFF_SIZE		16
+#define FTS2BA61Y_PANEL_INFO_SIZE		11
+#define FTS2BA61Y_RESET_CMD_SIZE		5
+#define FTS2BA61Y_EVENT_COUNT			31
+#define MAX_TRANSFER_SIZE			256
+
+enum fts2ba61y_regulators {
+	FTS2BA61Y_REGULATOR_VDD,
+	FTS2BA61Y_REGULATOR_AVDD,
+};
+
+struct fts2ba61y_data {
+	struct spi_device *spi;
+	struct regulator_bulk_data regulators[2];
+	struct input_dev *input_dev;
+	struct mutex mutex;
+	struct touchscreen_properties prop;
+
+	u8 tx_count;
+
+	unsigned int max_x;
+	unsigned int max_y;
+};
+
+static int fts2ba61y_write(struct fts2ba61y_data *ts,
+			   u8 *reg, int cmd_len, u8 *data, int data_len)
+{
+	struct spi_message msg;
+	struct spi_transfer xfers;
+	char *tx_buf;
+	int len;
+	int ret;
+
+	tx_buf = kzalloc(cmd_len + data_len + 1, GFP_KERNEL);
+	if (!tx_buf) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	memset(&xfers, 0, sizeof(xfers));
+	spi_message_init(&msg);
+
+	memcpy(&tx_buf[0], reg, cmd_len);
+	if (data_len && data)
+		memcpy(&tx_buf[cmd_len], data, data_len);
+
+	len = cmd_len + data_len;
+
+	/* custom write cmd */
+	if (reg[0] != FTS2BA61Y_CMD_REG_W &&
+	    reg[0] != FTS2BA61Y_CMD_REG_R) {
+		memmove(tx_buf + 1, tx_buf, len);
+		tx_buf[0] = FTS2BA61Y_CMD_CUSTOM_W;
+		len++;
+	}
+
+	xfers.len = len;
+	xfers.tx_buf = tx_buf;
+
+	spi_message_add_tail(&xfers, &msg);
+
+	mutex_lock(&ts->mutex);
+	ret = spi_sync(ts->spi, &msg);
+	if (ret)
+		dev_err(&ts->spi->dev, "spi transfer error, %d", ret);
+	mutex_unlock(&ts->mutex);
+
+out:
+	kfree(tx_buf);
+	return ret;
+}
+
+static int fts2ba61y_spi_raw_read(struct fts2ba61y_data *ts,
+				  u8 *tx_buf, u8 *rx_buf, int len)
+{
+	struct spi_message msg;
+	struct spi_transfer xfer;
+	int ret;
+
+	memset(&xfer, 0, sizeof(xfer));
+	spi_message_init(&msg);
+
+	xfer.len = len;
+	xfer.tx_buf = tx_buf;
+	xfer.rx_buf = rx_buf;
+	spi_message_add_tail(&xfer, &msg);
+
+	mutex_lock(&ts->mutex);
+	ret = spi_sync(ts->spi, &msg);
+	if (ret)
+		dev_err(&ts->spi->dev, "spi transfer error, %d", ret);
+	mutex_unlock(&ts->mutex);
+
+	return ret;
+}
+
+/*
+ * higher-level wrapper that prepares the buffers for a read.
+ */
+static int fts2ba61y_read(struct fts2ba61y_data *ts,
+			  u8 reg[], int tx_len, u8 buf[], int rx_len)
+{
+	char *tx_buf, *rx_buf;
+	int ret, mem_len;
+	u16 reg_val;
+
+	if (tx_len > 3)
+		mem_len = rx_len + 1 + tx_len;
+	else
+		mem_len = rx_len + 4;
+
+	tx_buf = kzalloc(mem_len, GFP_KERNEL);
+	rx_buf = kzalloc(mem_len, GFP_KERNEL);
+	if (!tx_buf || !rx_buf) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	switch (reg[0]) {
+	case FTS2BA61Y_CMD_READ_EVENT:
+	case FTS2BA61Y_CMD_REG_W:
+	case FTS2BA61Y_CMD_REG_R:
+		memcpy(tx_buf, reg, tx_len);
+		break;
+
+	default:
+		tx_buf[0] = FTS2BA61Y_CMD_CUSTOM_R;
+
+		if (tx_len == 1)
+			reg_val = 0;
+		else if (tx_len == 2)
+			reg_val = reg[0];
+		else if (tx_len == 3)
+			reg_val = reg[0] | (reg[1] << 8);
+		else {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		tx_len = 3;
+		put_unaligned_be16(reg_val, &tx_buf[1]);
+
+		ret = fts2ba61y_write(ts, reg, 1, NULL, 0);
+		if (ret < 0)
+			goto out;
+		break;
+	}
+
+	ret = fts2ba61y_spi_raw_read(ts, tx_buf, rx_buf, rx_len + 1 + tx_len);
+	if (ret < 0)
+		goto out;
+
+	memcpy(buf, &rx_buf[1 + tx_len], rx_len);
+
+out:
+	kfree(tx_buf);
+	kfree(rx_buf);
+	return ret;
+}
+
+static int fts2ba61y_wait_for_ready(struct fts2ba61y_data *ts)
+{
+	u8 buffer[FTS2BA61Y_EVENT_BUFF_SIZE];
+	u8 cmd = FTS2BA61Y_CMD_READ_EVENT;
+	u8 status_id, stype;
+	int ret;
+
+	for (int retries = 5; retries > 0; retries--) {
+		ret = fts2ba61y_read(ts, &cmd, 1, buffer, FTS2BA61Y_EVENT_BUFF_SIZE);
+
+		stype = FIELD_GET(FTS2BA61Y_MASK_STYPE, buffer[0]);
+		status_id = buffer[1];
+
+		if (stype == FTS2BA61Y_EVENT_STATUSTYPE_INFO &&
+		    status_id == FTS2BA61Y_INFO_READY_STATUS) {
+			ret = 0;
+			break;
+		} else
+			ret = -ENODEV;
+
+		msleep(20);
+	}
+
+	return ret;
+}
+
+static int fts2ba61y_reset(struct fts2ba61y_data *ts)
+{
+	u8 cmd = FTS2BA61Y_CMD_REG_W;
+	/* the following sequence is undocumented */
+	u8 reset[FTS2BA61Y_RESET_CMD_SIZE] = { 0x20, 0x00,
+					       0x00, 0x24, 0x81 };
+	int ret;
+
+	disable_irq(ts->spi->irq);
+
+	ret = fts2ba61y_write(ts, &cmd, 1, &reset[0], FTS2BA61Y_RESET_CMD_SIZE);
+	if (ret)
+		return ret;
+	msleep(30);
+
+	ret = fts2ba61y_wait_for_ready(ts);
+	if (ret)
+		return ret;
+
+	enable_irq(ts->spi->irq);
+
+	return 0;
+}
+
+static int fts2ba61y_set_channels(struct fts2ba61y_data *ts)
+{
+	int ret;
+	u8 cmd = FTS2BA61Y_CMD_READ_PANEL_INFO;
+	u8 data[FTS2BA61Y_PANEL_INFO_SIZE];
+
+	ret = fts2ba61y_read(ts, &cmd, 1, data, FTS2BA61Y_PANEL_INFO_SIZE);
+	if (ret)
+		return ret;
+
+	ts->max_x = get_unaligned_be16(data);
+	ts->max_y = get_unaligned_be16(data + 2);
+
+	/* if no tx channels defined, at least keep one */
+	ts->tx_count = max_t(u8, data[8], 1);
+
+	return 0;
+}
+
+static int fts2ba61y_set_touch_func(struct fts2ba61y_data *ts)
+{
+	u8 cmd = FTS2BA61Y_CMD_TOUCHTYPE;
+	u16 touchtype = cpu_to_le16(FTS2BA61Y_TOUCHTYPE_DEFAULT);
+
+	return fts2ba61y_write(ts, &cmd, 1, (u8 *)&touchtype, 2);
+}
+
+static int fts2ba61y_hw_init(struct fts2ba61y_data *ts)
+{
+	int ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ts->regulators),
+								ts->regulators);
+	if (ret)
+		return ret;
+
+	msleep(140);
+
+	ret = fts2ba61y_reset(ts);
+	if (ret)
+		return ret;
+
+	ret = fts2ba61y_set_channels(ts);
+	if (ret)
+		return ret;
+
+	return fts2ba61y_set_touch_func(ts);
+}
+
+static int fts2ba61y_get_event(struct fts2ba61y_data *ts, u8 *data, int *n_events)
+{
+	int ret;
+	u8 cmd = FTS2BA61Y_CMD_READ_EVENT;
+
+	ret = fts2ba61y_read(ts, &cmd, 1, data, FTS2BA61Y_EVENT_BUFF_SIZE);
+	if (ret < 0)
+		return ret;
+
+	if (!data[0]) {
+		*n_events = 0;
+		return 0;
+	}
+
+	*n_events = FIELD_GET(FTS2BA61Y_MASK_LEFT_EVENTS, data[7]);
+	if (unlikely(*n_events >= FTS2BA61Y_EVENT_COUNT)) {
+		cmd = FTS2BA61Y_CMD_CLEAR_EVENTS;
+		fts2ba61y_write(ts, &cmd, 1, NULL, 0);
+		*n_events = 0;
+		return -EINVAL;
+	}
+
+	if (*n_events > 0) {
+		ret = fts2ba61y_read(ts, &cmd, 1,
+				     &data[1 * FTS2BA61Y_EVENT_BUFF_SIZE],
+				     FTS2BA61Y_EVENT_BUFF_SIZE * (*n_events));
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void fts2ba61y_report_coordinates(struct fts2ba61y_data *ts,
+					 u8 *event, u8 tid)
+{
+	u8 major = event[4];
+	u8 minor = event[5];
+	u8 z = FIELD_GET(FTS2BA61Y_MASK_Z, event[6]);
+
+	u16 x = (event[1] << 4) |
+		FIELD_GET(FTS2BA61Y_MASK_X_3_0, event[3]);
+	u16 y = (event[2] << 4) |
+		FIELD_GET(FTS2BA61Y_MASK_Y_3_0, event[3]);
+	u16 ttype = (FIELD_GET(FTS2BA61Y_MASK_TTYPE_3_2, event[6]) << 2) |
+		    (FIELD_GET(FTS2BA61Y_MASK_TTYPE_1_0, event[7]) << 0);
+
+	if (ttype != FTS2BA61Y_TOUCHTYPE_NORMAL &&
+	    ttype != FTS2BA61Y_TOUCHTYPE_PALM &&
+	    ttype != FTS2BA61Y_TOUCHTYPE_WET &&
+	    ttype != FTS2BA61Y_TOUCHTYPE_GLOVE)
+		return;
+
+	input_mt_slot(ts->input_dev, tid);
+	input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER, true);
+	input_report_abs(ts->input_dev, ABS_MT_POSITION_X, x);
+	input_report_abs(ts->input_dev, ABS_MT_POSITION_Y, y);
+	input_report_abs(ts->input_dev, ABS_MT_TOUCH_MAJOR, major);
+	input_report_abs(ts->input_dev, ABS_MT_TOUCH_MINOR, minor);
+	input_report_abs(ts->input_dev, ABS_MT_PRESSURE, z);
+
+	input_mt_sync_frame(ts->input_dev);
+	input_sync(ts->input_dev);
+}
+
+static void fts2ba61y_report_release(struct fts2ba61y_data *ts, u8 tid)
+{
+	input_mt_slot(ts->input_dev, tid);
+	input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER, false);
+
+	input_mt_sync_frame(ts->input_dev);
+	input_sync(ts->input_dev);
+}
+
+static void fts2ba61y_handle_coordinates(struct fts2ba61y_data *ts, u8 *event)
+{
+	u8 t_id = FIELD_GET(FTS2BA61Y_MASK_TID, event[0]);
+	u8 action = FIELD_GET(FTS2BA61Y_MASK_TCHSTA, event[0]);
+
+	if (t_id > ts->tx_count)
+		return;
+
+	switch (action) {
+	case FTS2BA61Y_COORDINATE_ACTION_PRESS:
+	case FTS2BA61Y_COORDINATE_ACTION_MOVE:
+		fts2ba61y_report_coordinates(ts, event, t_id);
+		break;
+
+	case FTS2BA61Y_COORDINATE_ACTION_RELEASE:
+		fts2ba61y_report_release(ts, t_id);
+		break;
+	}
+}
+
+static irqreturn_t fts2ba61y_irq_handler(int irq, void *handle)
+{
+	struct fts2ba61y_data *ts = handle;
+	u8 buffer[FTS2BA61Y_EVENT_COUNT * FTS2BA61Y_EVENT_BUFF_SIZE];
+	u8 *event;
+	u8 event_id;
+	int n_events = 0;
+	int ret;
+
+	usleep(1);
+
+	ret = fts2ba61y_get_event(ts, buffer, &n_events);
+	if (ret < 0) {
+		dev_dbg(&ts->spi->dev, "failed to get event: %d", ret);
+		return IRQ_HANDLED;
+	}
+
+	for (int i = 0; i <= n_events; i++) {
+		event = &buffer[i * FTS2BA61Y_EVENT_BUFF_SIZE];
+		event_id = FIELD_GET(FTS2BA61Y_MASK_EVENT_ID, event[0]);
+
+		if (event_id == FTS2BA61Y_COORDINATE_EVENT)
+			fts2ba61y_handle_coordinates(ts, event);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int fts2ba61y_input_open(struct input_dev *dev)
+{
+	struct fts2ba61y_data *ts = input_get_drvdata(dev);
+	u8 cmd = FTS2BA61Y_CMD_SENSE_ON;
+
+	return fts2ba61y_write(ts, &cmd, 1, NULL, 0);
+}
+
+static void fts2ba61y_input_close(struct input_dev *dev)
+{
+	struct fts2ba61y_data *ts = input_get_drvdata(dev);
+	int ret;
+	u8 cmd = FTS2BA61Y_CMD_SENSE_OFF;
+
+	ret = fts2ba61y_write(ts, &cmd, 1, NULL, 0);
+	if (ret)
+		dev_err(&ts->spi->dev, "failed to turn off sensing\n");
+}
+
+static void fts2ba61y_power_off(void *data)
+{
+	struct fts2ba61y_data *ts = data;
+
+	disable_irq(ts->spi->irq);
+	regulator_bulk_disable(ARRAY_SIZE(ts->regulators),
+						   ts->regulators);
+}
+
+static int fts2ba61y_probe(struct spi_device *spi) {
+	struct fts2ba61y_data *ts;
+	struct input_dev *input_dev;
+	int error;
+
+	ts = devm_kzalloc(&spi->dev, sizeof(*ts), GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
+
+	ts->spi = spi;
+	mutex_init(&ts->mutex);
+
+	spi->mode = SPI_MODE_0;
+	spi->bits_per_word = 8;
+
+	error = spi_setup(spi);
+	if (error)
+		return error;
+
+	ts->regulators[FTS2BA61Y_REGULATOR_VDD].supply = "vdd";
+	ts->regulators[FTS2BA61Y_REGULATOR_AVDD].supply = "avdd";
+	error = devm_regulator_bulk_get(&spi->dev,
+									ARRAY_SIZE(ts->regulators),
+									ts->regulators);
+	if (error)
+		return error;
+
+	error = fts2ba61y_hw_init(ts);
+	if (error)
+		return error;
+
+	error = devm_add_action_or_reset(&ts->spi->dev, fts2ba61y_power_off, ts);
+	if (error)
+		return error;
+
+	input_dev = devm_input_allocate_device(&spi->dev);
+	if (!input_dev)
+		return -ENOMEM;
+
+	ts->input_dev = input_dev;
+
+	input_dev->name = FTS2BA61Y_DEV_NAME;
+	input_dev->id.bustype = BUS_SPI;
+	input_dev->open = fts2ba61y_input_open;
+	input_dev->close = fts2ba61y_input_close;
+
+	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, ts->max_x, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, ts->max_y, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 255, 0, 0);
+
+	touchscreen_parse_properties(input_dev, true, &ts->prop);
+
+	spi_set_drvdata(spi, ts);
+	input_set_drvdata(input_dev, ts);
+
+	error = input_mt_init_slots(input_dev, ts->tx_count, INPUT_MT_DIRECT);
+	if (error)
+		return error;
+
+	error = input_register_device(input_dev);
+	if (error)
+		return error;
+
+	error = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
+					  fts2ba61y_irq_handler,
+					  IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+					  "fts2ba61y_irq", ts);
+	return error;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id spi_touchscreen_dt_ids[] = {
+	{ .compatible = "st,fts2ba61y" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, spi_touchscreen_dt_ids);
+#endif
+
+static const struct spi_device_id fts2ba61y_spi_ids[] = {
+	{ "fts2ba61y" },
+	{ },
+};
+MODULE_DEVICE_TABLE(spi, fts2ba61y_spi_ids);
+
+static struct spi_driver spi_touchscreen_driver = {
+	.driver = {
+		.name = FTS2BA61Y_DEV_NAME,
+		.of_match_table = of_match_ptr(spi_touchscreen_dt_ids),
+	},
+	.probe = fts2ba61y_probe,
+	.id_table = fts2ba61y_spi_ids,
+};
+
+module_spi_driver(spi_touchscreen_driver);
+
+MODULE_AUTHOR("Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>");
+MODULE_DESCRIPTION("ST-Microelectronics FTS2BA61Y Touch Screen");
+MODULE_LICENSE("GPL");
-- 
2.50.1

Re: [RFC PATCH 0/2] Input: add fts2ba61y touchscreen driver

[Krzysztof Kozlowski]

On 11/09/2025 23:19, Eric Gonçalves wrote:
> This patchset adds support for the ST-Microelectronics FTS2BA61Y,
> a capacitive multi-touch touchscreen controller. this touchscreen
> is used in many mobile devices, like ones from the Galaxy S22 series
> and the Z Fold 5. Ivaylo Ivanov wrote the driver originally,
> and I'm upstreaming it on his behalf.
> 
RFC means patchset is not ready, so please always mention why it is not
ready or what you expect here.

Best regards,
Krzysztof

Re: [RFC PATCH 1/2] dt-bindings: input: add ST-Microelectronics FTS2BA61Y touchscreen binding

[Krzysztof Kozlowski]

On 11/09/2025 23:19, Eric Gonçalves wrote:
> Add the bindings for ST-Microelectronics FTS2BA61Y capacitive touchscreen.

Please wrap commit message according to Linux coding style / submission
process (neither too early nor over the limit):
https://elixir.bootlin.com/linux/v6.4-rc1/source/Documentation/process/submitting-patches.rst#L597

A nit, subject: drop second/last, redundant "bindings". The
"dt-bindings" prefix is already stating that these are bindings.
See also:
https://elixir.bootlin.com/linux/v6.17-rc3/source/Documentation/devicetree/bindings/submitting-patches.rst#L18

> 
> Signed-off-by: Eric Gonçalves <ghatto404@gmail.com>



> +
> +properties:
> +  compatible:
> +    const: st,fts2ba61y
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  avdd-supply: true
> +  vdd-supply: true
> +
> +unevaluatedProperties: false

This goes after required: field.

Other than that - why isn't this finished (non RFC)? Code looks ok, but
I also did not look that thorough.

Best regards,
Krzysztof

Re: [RFC PATCH 0/2] Input: add fts2ba61y touchscreen driver

[Ivaylo Ivanov]

On 9/14/25 17:47, Krzysztof Kozlowski wrote:
> On 11/09/2025 23:19, Eric Gonçalves wrote:
>> This patchset adds support for the ST-Microelectronics FTS2BA61Y,
>> a capacitive multi-touch touchscreen controller. this touchscreen
>> is used in many mobile devices, like ones from the Galaxy S22 series
>> and the Z Fold 5. Ivaylo Ivanov wrote the driver originally,
>> and I'm upstreaming it on his behalf.
>>
> RFC means patchset is not ready, so please always mention why it is not
> ready or what you expect here.

I'm not sure if naming the compatible as it is currently is correct.
The specific thing about this IC seems to be that it's flashed with
samsung-made firmware, so I need to confirm that:
- we don't want to match compatible with the IC name (the same IC may
be shipped with different fw on other devices)
- maintainers wouldn't want us to merge it with some other driver

Best regards,
Ivaylo

>
> Best regards,
> Krzysztof

Re: [RFC PATCH 1/2] dt-bindings: input: add ST-Microelectronics FTS2BA61Y touchscreen binding

[Eric Gonçalves]

On September 14, 2025 11:48:49 AM GMT-03:00, Krzysztof Kozlowski <krzk@kernel.org> wrote:
>On 11/09/2025 23:19, Eric Gonçalves wrote:
>> Add the bindings for ST-Microelectronics FTS2BA61Y capacitive touchscreen.
>
>Please wrap commit message according to Linux coding style / submission
>process (neither too early nor over the limit):
>https://elixir.bootlin.com/linux/v6.4-rc1/source/Documentation/process/submitting-patches.rst#L597
The commit description is 74 characters
long, and the name is 73?
>
>A nit, subject: drop second/last, redundant "bindings". The
>"dt-bindings" prefix is already stating that these are bindings.
>See also:
>https://elixir.bootlin.com/linux/v6.17-rc3/source/Documentation/devicetree/bindings/submitting-patches.rst#L18
Thanks, will do!
>> 
>> Signed-off-by: Eric Gonçalves <ghatto404@gmail.com>
>
>
>
>> +
>> +properties:
>> +  compatible:
>> +    const: st,fts2ba61y
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  interrupts:
>> +    maxItems: 1
>> +
>> +  avdd-supply: true
>> +  vdd-supply: true
>> +
>> +unevaluatedProperties: false
>
>This goes after required: field.
>
>Other than that - why isn't this finished (non RFC)? Code looks ok, but
>I also did not look that thorough.
>
>Best regards,
>Krzysztof

Re: [RFC PATCH 1/2] dt-bindings: input: add ST-Microelectronics FTS2BA61Y touchscreen binding

[Krzysztof Kozlowski]

On 14/09/2025 18:16, Eric Gonçalves wrote:
> 
> 
> On September 14, 2025 11:48:49 AM GMT-03:00, Krzysztof Kozlowski <krzk@kernel.org> wrote:
>> On 11/09/2025 23:19, Eric Gonçalves wrote:
>>> Add the bindings for ST-Microelectronics FTS2BA61Y capacitive touchscreen.
>>
>> Please wrap commit message according to Linux coding style / submission
>> process (neither too early nor over the limit):
>> https://elixir.bootlin.com/linux/v6.4-rc1/source/Documentation/process/submitting-patches.rst#L597
> The commit description is 74 characters
> long, and the name is 73?


Ah, sorry, misjudged.


Best regards,
Krzysztof