iio: proximity: isl29501: Fix return type of isl29501_register_writegrafted

isl29501_register_write() was returning a u32 instead of an int.
Since the function returns negative error codes (such as -ERANGE or
return values from i2c_smbus_write_byte_data()), returning an unsigned
integer type prevents callers from correctly checking for negative error
conditions.

Fix this by changing the function return type from u32 to int.

This was found through manual code review.

Fixes: 1c28799257bc ("iio: light: isl29501: Add support for the ISL29501 ToF sensor.")
Signed-off-by: Salah Triki <salah.triki@gmail.com>
Reviewed-by: Joshua Crofts <joshua.crofts1@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

1 files changed, 172 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/tsc40.c b/drivers/input/touchscreen/tsc40.c
new file mode 100644
index 000000000..2a28a309e
--- /dev/null
+++ b/drivers/input/touchscreen/tsc40.c
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TSC-40 serial touchscreen driver. It should be compatible with
+ * TSC-10 and 25.
+ *
+ * Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/serio.h>
+
+#define PACKET_LENGTH  5
+struct tsc_ser {
+	struct input_dev *dev;
+	struct serio *serio;
+	u32 idx;
+	unsigned char data[PACKET_LENGTH];
+	char phys[32];
+};
+
+static void tsc_process_data(struct tsc_ser *ptsc)
+{
+	struct input_dev *dev = ptsc->dev;
+	u8 *data = ptsc->data;
+	u32 x;
+	u32 y;
+
+	x = ((data[1] & 0x03) << 8) | data[2];
+	y = ((data[3] & 0x03) << 8) | data[4];
+
+	input_report_abs(dev, ABS_X, x);
+	input_report_abs(dev, ABS_Y, y);
+	input_report_key(dev, BTN_TOUCH, 1);
+
+	input_sync(dev);
+}
+
+static irqreturn_t tsc_interrupt(struct serio *serio,
+		unsigned char data, unsigned int flags)
+{
+	struct tsc_ser *ptsc = serio_get_drvdata(serio);
+	struct input_dev *dev = ptsc->dev;
+
+	ptsc->data[ptsc->idx] = data;
+	switch (ptsc->idx++) {
+	case 0:
+		if (unlikely((data & 0x3e) != 0x10)) {
+			dev_dbg(&serio->dev,
+				"unsynchronized packet start (0x%02x)\n", data);
+			ptsc->idx = 0;
+		} else if (!(data & 0x01)) {
+			input_report_key(dev, BTN_TOUCH, 0);
+			input_sync(dev);
+			ptsc->idx = 0;
+		}
+		break;
+
+	case 1:
+	case 3:
+		if (unlikely(data & 0xfc)) {
+			dev_dbg(&serio->dev,
+				"unsynchronized data 0x%02x at offset %d\n",
+				data, ptsc->idx - 1);
+			ptsc->idx = 0;
+		}
+		break;
+
+	case 4:
+		tsc_process_data(ptsc);
+		ptsc->idx = 0;
+		break;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int tsc_connect(struct serio *serio, struct serio_driver *drv)
+{
+	struct tsc_ser *ptsc;
+	struct input_dev *input_dev;
+	int error;
+
+	ptsc = kzalloc_obj(*ptsc);
+	input_dev = input_allocate_device();
+	if (!ptsc || !input_dev) {
+		error = -ENOMEM;
+		goto fail1;
+	}
+
+	ptsc->serio = serio;
+	ptsc->dev = input_dev;
+	scnprintf(ptsc->phys, sizeof(ptsc->phys), "%s/input0", serio->phys);
+
+	input_dev->name = "TSC-10/25/40 Serial TouchScreen";
+	input_dev->phys = ptsc->phys;
+	input_dev->id.bustype = BUS_RS232;
+	input_dev->id.vendor = SERIO_TSC40;
+	input_dev->id.product = 40;
+	input_dev->id.version = 0x0001;
+	input_dev->dev.parent = &serio->dev;
+
+	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	__set_bit(BTN_TOUCH, input_dev->keybit);
+	input_set_abs_params(ptsc->dev, ABS_X, 0, 0x3ff, 0, 0);
+	input_set_abs_params(ptsc->dev, ABS_Y, 0, 0x3ff, 0, 0);
+
+	serio_set_drvdata(serio, ptsc);
+
+	error = serio_open(serio, drv);
+	if (error)
+		goto fail2;
+
+	error = input_register_device(ptsc->dev);
+	if (error)
+		goto fail3;
+
+	return 0;
+
+fail3:
+	serio_close(serio);
+fail2:
+	serio_set_drvdata(serio, NULL);
+fail1:
+	input_free_device(input_dev);
+	kfree(ptsc);
+	return error;
+}
+
+static void tsc_disconnect(struct serio *serio)
+{
+	struct tsc_ser *ptsc = serio_get_drvdata(serio);
+
+	serio_close(serio);
+
+	input_unregister_device(ptsc->dev);
+	kfree(ptsc);
+
+	serio_set_drvdata(serio, NULL);
+}
+
+static const struct serio_device_id tsc_serio_ids[] = {
+	{
+		.type   = SERIO_RS232,
+		.proto  = SERIO_TSC40,
+		.id     = SERIO_ANY,
+		.extra  = SERIO_ANY,
+	},
+	{ 0 }
+};
+MODULE_DEVICE_TABLE(serio, tsc_serio_ids);
+
+#define DRIVER_DESC    "TSC-10/25/40 serial touchscreen driver"
+
+static struct serio_driver tsc_drv = {
+	.driver	= {
+		.name   = "tsc40",
+	},
+	.description    = DRIVER_DESC,
+	.id_table	= tsc_serio_ids,
+	.interrupt      = tsc_interrupt,
+	.connect	= tsc_connect,
+	.disconnect     = tsc_disconnect,
+};
+
+module_serio_driver(tsc_drv);
+
+MODULE_AUTHOR("Sebastian Andrzej Siewior <bigeasy@linutronix.de>");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL v2");