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, 174 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-pl030.c b/drivers/rtc/rtc-pl030.c
new file mode 100644
index 000000000..5caaa714f
--- /dev/null
+++ b/drivers/rtc/rtc-pl030.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/drivers/rtc/rtc-pl030.c
+ *
+ *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
+ */
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/amba/bus.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#define RTC_DR		(0)
+#define RTC_MR		(4)
+#define RTC_STAT	(8)
+#define RTC_EOI		(8)
+#define RTC_LR		(12)
+#define RTC_CR		(16)
+#define RTC_CR_MIE	(1 << 0)
+
+struct pl030_rtc {
+	void __iomem		*base;
+};
+
+static irqreturn_t pl030_interrupt(int irq, void *dev_id)
+{
+	struct pl030_rtc *rtc = dev_id;
+	writel(0, rtc->base + RTC_EOI);
+	return IRQ_HANDLED;
+}
+
+static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct pl030_rtc *rtc = dev_get_drvdata(dev);
+
+	rtc_time64_to_tm(readl(rtc->base + RTC_MR), &alrm->time);
+	return 0;
+}
+
+static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct pl030_rtc *rtc = dev_get_drvdata(dev);
+
+	writel(rtc_tm_to_time64(&alrm->time), rtc->base + RTC_MR);
+
+	return 0;
+}
+
+static int pl030_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct pl030_rtc *rtc = dev_get_drvdata(dev);
+
+	rtc_time64_to_tm(readl(rtc->base + RTC_DR), tm);
+
+	return 0;
+}
+
+/*
+ * Set the RTC time.  Unfortunately, we can't accurately set
+ * the point at which the counter updates.
+ *
+ * Also, since RTC_LR is transferred to RTC_CR on next rising
+ * edge of the 1Hz clock, we must write the time one second
+ * in advance.
+ */
+static int pl030_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct pl030_rtc *rtc = dev_get_drvdata(dev);
+
+	writel(rtc_tm_to_time64(tm) + 1, rtc->base + RTC_LR);
+
+	return 0;
+}
+
+static const struct rtc_class_ops pl030_ops = {
+	.read_time	= pl030_read_time,
+	.set_time	= pl030_set_time,
+	.read_alarm	= pl030_read_alarm,
+	.set_alarm	= pl030_set_alarm,
+};
+
+static int pl030_probe(struct amba_device *dev, const struct amba_id *id)
+{
+	struct pl030_rtc *rtc;
+	int ret;
+	struct rtc_device *rtc_dev;
+
+	ret = amba_request_regions(dev, NULL);
+	if (ret)
+		goto err_req;
+
+	rtc = devm_kzalloc(&dev->dev, sizeof(*rtc), GFP_KERNEL);
+	if (!rtc) {
+		ret = -ENOMEM;
+		goto err_rtc;
+	}
+
+	rtc_dev = devm_rtc_allocate_device(&dev->dev);
+	if (IS_ERR(rtc_dev)) {
+		ret = PTR_ERR(rtc_dev);
+		goto err_rtc;
+	}
+
+	rtc_dev->ops = &pl030_ops;
+	rtc_dev->range_max = U32_MAX;
+	rtc->base = ioremap(dev->res.start, resource_size(&dev->res));
+	if (!rtc->base) {
+		ret = -ENOMEM;
+		goto err_rtc;
+	}
+
+	__raw_writel(0, rtc->base + RTC_CR);
+	__raw_writel(0, rtc->base + RTC_EOI);
+
+	amba_set_drvdata(dev, rtc);
+
+	ret = request_irq(dev->irq[0], pl030_interrupt, 0,
+			  "rtc-pl030", rtc);
+	if (ret)
+		goto err_irq;
+
+	ret = devm_rtc_register_device(rtc_dev);
+	if (ret)
+		goto err_reg;
+
+	return 0;
+
+ err_reg:
+	free_irq(dev->irq[0], rtc);
+ err_irq:
+	iounmap(rtc->base);
+ err_rtc:
+	amba_release_regions(dev);
+ err_req:
+	return ret;
+}
+
+static void pl030_remove(struct amba_device *dev)
+{
+	struct pl030_rtc *rtc = amba_get_drvdata(dev);
+
+	writel(0, rtc->base + RTC_CR);
+
+	free_irq(dev->irq[0], rtc);
+	iounmap(rtc->base);
+	amba_release_regions(dev);
+}
+
+static const struct amba_id pl030_ids[] = {
+	{
+		.id	= 0x00041030,
+		.mask	= 0x000fffff,
+	},
+	{ 0, 0 },
+};
+
+MODULE_DEVICE_TABLE(amba, pl030_ids);
+
+static struct amba_driver pl030_driver = {
+	.drv		= {
+		.name	= "rtc-pl030",
+	},
+	.probe		= pl030_probe,
+	.remove		= pl030_remove,
+	.id_table	= pl030_ids,
+};
+
+module_amba_driver(pl030_driver);
+
+MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
+MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver");
+MODULE_LICENSE("GPL");