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, 96 insertions, 0 deletions

diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
new file mode 100644
index 000000000..69eed058e
--- /dev/null
+++ b/drivers/base/platform-msi.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MSI framework for platform devices
+ *
+ * Copyright (C) 2015 ARM Limited, All Rights Reserved.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ * Copyright (C) 2022 Linutronix GmbH
+ */
+
+#include <linux/device.h>
+#include <linux/irqdomain.h>
+#include <linux/msi.h>
+
+/*
+ * This indirection can go when platform_device_msi_init_and_alloc_irqs()
+ * is switched to a proper irq_chip::irq_write_msi_msg() callback. Keep it
+ * simple for now.
+ */
+static void platform_msi_write_msi_msg(struct irq_data *d, struct msi_msg *msg)
+{
+	irq_write_msi_msg_t cb = d->chip_data;
+
+	cb(irq_data_get_msi_desc(d), msg);
+}
+
+static void platform_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
+{
+	arg->desc = desc;
+	arg->hwirq = desc->msi_index;
+}
+
+static const struct msi_domain_template platform_msi_template = {
+	.chip = {
+		.name			= "pMSI",
+		.irq_mask		= irq_chip_mask_parent,
+		.irq_unmask		= irq_chip_unmask_parent,
+		.irq_write_msi_msg	= platform_msi_write_msi_msg,
+		/* The rest is filled in by the platform MSI parent */
+	},
+
+	.ops = {
+		.set_desc		= platform_msi_set_desc,
+	},
+
+	.info = {
+		.bus_token		= DOMAIN_BUS_DEVICE_MSI,
+	},
+};
+
+/**
+ * platform_device_msi_init_and_alloc_irqs - Initialize platform device MSI
+ *					     and allocate interrupts for @dev
+ * @dev:		The device for which to allocate interrupts
+ * @nvec:		The number of interrupts to allocate
+ * @write_msi_msg:	Callback to write an interrupt message for @dev
+ *
+ * Returns:
+ * Zero for success, or an error code in case of failure
+ *
+ * This creates a MSI domain on @dev which has @dev->msi.domain as
+ * parent. The parent domain sets up the new domain. The domain has
+ * a fixed size of @nvec. The domain is managed by devres and will
+ * be removed when the device is removed.
+ */
+int platform_device_msi_init_and_alloc_irqs(struct device *dev, unsigned int nvec,
+					    irq_write_msi_msg_t write_msi_msg)
+{
+	struct irq_domain *domain = dev->msi.domain;
+
+	if (!domain || !write_msi_msg)
+		return -EINVAL;
+
+	/*
+	 * @write_msi_msg is stored in the resulting msi_domain_info::data.
+	 * The underlying domain creation mechanism will assign that
+	 * callback to the resulting irq chip.
+	 */
+	if (!msi_create_device_irq_domain(dev, MSI_DEFAULT_DOMAIN,
+					  &platform_msi_template,
+					  nvec, NULL, write_msi_msg))
+		return -ENODEV;
+
+	return msi_domain_alloc_irqs_range(dev, MSI_DEFAULT_DOMAIN, 0, nvec - 1);
+}
+EXPORT_SYMBOL_GPL(platform_device_msi_init_and_alloc_irqs);
+
+/**
+ * platform_device_msi_free_irqs_all - Free all interrupts for @dev
+ * @dev:	The device for which to free interrupts
+ */
+void platform_device_msi_free_irqs_all(struct device *dev)
+{
+	msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN);
+	msi_remove_device_irq_domain(dev, MSI_DEFAULT_DOMAIN);
+}
+EXPORT_SYMBOL_GPL(platform_device_msi_free_irqs_all);