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, 89 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/tsc2005.c b/drivers/input/touchscreen/tsc2005.c
new file mode 100644
index 000000000..6fe8b41b3
--- /dev/null
+++ b/drivers/input/touchscreen/tsc2005.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TSC2005 touchscreen driver
+ *
+ * Copyright (C) 2006-2010 Nokia Corporation
+ * Copyright (C) 2015 QWERTY Embedded Design
+ * Copyright (C) 2015 EMAC Inc.
+ *
+ * Based on original tsc2005.c by Lauri Leukkunen <lauri.leukkunen@nokia.com>
+ */
+
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/spi/spi.h>
+#include <linux/regmap.h>
+#include "tsc200x-core.h"
+
+static const struct input_id tsc2005_input_id = {
+	.bustype = BUS_SPI,
+	.product = 2005,
+};
+
+static int tsc2005_cmd(struct device *dev, u8 cmd)
+{
+	u8 tx = TSC200X_CMD | TSC200X_CMD_12BIT | cmd;
+	struct spi_transfer xfer = {
+		.tx_buf         = &tx,
+		.len            = 1,
+		.bits_per_word  = 8,
+	};
+	struct spi_message msg;
+	struct spi_device *spi = to_spi_device(dev);
+	int error;
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfer, &msg);
+
+	error = spi_sync(spi, &msg);
+	if (error) {
+		dev_err(dev, "%s: failed, command: %x, spi error: %d\n",
+			__func__, cmd, error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int tsc2005_probe(struct spi_device *spi)
+{
+	int error;
+
+	spi->mode = SPI_MODE_0;
+	spi->bits_per_word = 8;
+	if (!spi->max_speed_hz)
+		spi->max_speed_hz = TSC2005_SPI_MAX_SPEED_HZ;
+
+	error = spi_setup(spi);
+	if (error)
+		return error;
+
+	return tsc200x_probe(&spi->dev, spi->irq, &tsc2005_input_id,
+			     devm_regmap_init_spi(spi, &tsc200x_regmap_config),
+			     tsc2005_cmd);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id tsc2005_of_match[] = {
+	{ .compatible = "ti,tsc2005" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, tsc2005_of_match);
+#endif
+
+static struct spi_driver tsc2005_driver = {
+	.driver	= {
+		.name		= "tsc2005",
+		.dev_groups	= tsc200x_groups,
+		.of_match_table	= of_match_ptr(tsc2005_of_match),
+		.pm		= pm_sleep_ptr(&tsc200x_pm_ops),
+	},
+	.probe	= tsc2005_probe,
+};
+module_spi_driver(tsc2005_driver);
+
+MODULE_AUTHOR("Michael Welling <mwelling@ieee.org>");
+MODULE_DESCRIPTION("TSC2005 Touchscreen Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:tsc2005");