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, 218 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-ftrtc010.c b/drivers/rtc/rtc-ftrtc010.c
new file mode 100644
index 000000000..98fa0f518
--- /dev/null
+++ b/drivers/rtc/rtc-ftrtc010.c
@@ -0,0 +1,218 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Faraday Technology FTRTC010 driver
+ *
+ *  Copyright (C) 2009 Janos Laube <janos.dev@gmail.com>
+ *
+ * Original code for older kernel 2.6.15 are from Stormlinksemi
+ * first update from Janos Laube for > 2.6.29 kernels
+ *
+ * checkpatch fixes and usage of rtc-lib code
+ * Hans Ulli Kroll <ulli.kroll@googlemail.com>
+ */
+
+#include <linux/rtc.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+
+#define DRV_NAME        "rtc-ftrtc010"
+
+MODULE_AUTHOR("Hans Ulli Kroll <ulli.kroll@googlemail.com>");
+MODULE_DESCRIPTION("RTC driver for Gemini SoC");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
+
+struct ftrtc010_rtc {
+	void __iomem		*rtc_base;
+	int			rtc_irq;
+	struct clk		*pclk;
+	struct clk		*extclk;
+};
+
+enum ftrtc010_rtc_offsets {
+	FTRTC010_RTC_SECOND		= 0x00,
+	FTRTC010_RTC_MINUTE		= 0x04,
+	FTRTC010_RTC_HOUR		= 0x08,
+	FTRTC010_RTC_DAYS		= 0x0C,
+	FTRTC010_RTC_ALARM_SECOND	= 0x10,
+	FTRTC010_RTC_ALARM_MINUTE	= 0x14,
+	FTRTC010_RTC_ALARM_HOUR		= 0x18,
+	FTRTC010_RTC_RECORD		= 0x1C,
+	FTRTC010_RTC_CR			= 0x20,
+};
+
+static irqreturn_t ftrtc010_rtc_interrupt(int irq, void *dev)
+{
+	return IRQ_HANDLED;
+}
+
+/*
+ * Looks like the RTC in the Gemini SoC is (totaly) broken
+ * We can't read/write directly the time from RTC registers.
+ * We must do some "offset" calculation to get the real time
+ *
+ * This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does
+ * the same thing, without the rtc-lib.c calls.
+ */
+
+static int ftrtc010_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct ftrtc010_rtc *rtc = dev_get_drvdata(dev);
+
+	u32 days, hour, min, sec, offset;
+	timeu64_t time;
+
+	sec  = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
+	min  = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
+	hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
+	days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);
+	offset = readl(rtc->rtc_base + FTRTC010_RTC_RECORD);
+
+	time = offset + days * 86400 + hour * 3600 + min * 60 + sec;
+
+	rtc_time64_to_tm(time, tm);
+
+	return 0;
+}
+
+static int ftrtc010_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct ftrtc010_rtc *rtc = dev_get_drvdata(dev);
+	u32 sec, min, hour, day, offset;
+	timeu64_t time;
+
+	time = rtc_tm_to_time64(tm);
+
+	sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
+	min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
+	hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
+	day = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);
+
+	offset = time - (day * 86400 + hour * 3600 + min * 60 + sec);
+
+	writel(offset, rtc->rtc_base + FTRTC010_RTC_RECORD);
+	writel(0x01, rtc->rtc_base + FTRTC010_RTC_CR);
+
+	return 0;
+}
+
+static const struct rtc_class_ops ftrtc010_rtc_ops = {
+	.read_time     = ftrtc010_rtc_read_time,
+	.set_time      = ftrtc010_rtc_set_time,
+};
+
+static int ftrtc010_rtc_probe(struct platform_device *pdev)
+{
+	u32 days, hour, min, sec;
+	struct ftrtc010_rtc *rtc;
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct rtc_device *rtc_dev;
+	int ret;
+
+	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+	if (unlikely(!rtc))
+		return -ENOMEM;
+	platform_set_drvdata(pdev, rtc);
+
+	rtc->pclk = devm_clk_get(dev, "PCLK");
+	if (IS_ERR(rtc->pclk)) {
+		dev_err(dev, "could not get PCLK\n");
+	} else {
+		ret = clk_prepare_enable(rtc->pclk);
+		if (ret) {
+			dev_err(dev, "failed to enable PCLK\n");
+			return ret;
+		}
+	}
+	rtc->extclk = devm_clk_get(dev, "EXTCLK");
+	if (IS_ERR(rtc->extclk)) {
+		dev_err(dev, "could not get EXTCLK\n");
+	} else {
+		ret = clk_prepare_enable(rtc->extclk);
+		if (ret) {
+			dev_err(dev, "failed to enable EXTCLK\n");
+			goto err_disable_pclk;
+		}
+	}
+
+	rtc->rtc_irq = platform_get_irq(pdev, 0);
+	if (rtc->rtc_irq < 0) {
+		ret = rtc->rtc_irq;
+		goto err_disable_extclk;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		ret = -ENODEV;
+		goto err_disable_extclk;
+	}
+
+	rtc->rtc_base = devm_ioremap(dev, res->start,
+				     resource_size(res));
+	if (!rtc->rtc_base) {
+		ret = -ENOMEM;
+		goto err_disable_extclk;
+	}
+
+	rtc_dev = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rtc_dev)) {
+		ret = PTR_ERR(rtc_dev);
+		goto err_disable_extclk;
+	}
+
+	rtc_dev->ops = &ftrtc010_rtc_ops;
+
+	sec  = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
+	min  = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
+	hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
+	days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);
+
+	rtc_dev->range_min = (u64)days * 86400 + hour * 3600 + min * 60 + sec;
+	rtc_dev->range_max = U32_MAX + rtc_dev->range_min;
+
+	ret = devm_request_irq(dev, rtc->rtc_irq, ftrtc010_rtc_interrupt,
+			       IRQF_SHARED, pdev->name, dev);
+	if (unlikely(ret))
+		goto err_disable_extclk;
+
+	return devm_rtc_register_device(rtc_dev);
+
+err_disable_extclk:
+	clk_disable_unprepare(rtc->extclk);
+err_disable_pclk:
+	clk_disable_unprepare(rtc->pclk);
+	return ret;
+}
+
+static void ftrtc010_rtc_remove(struct platform_device *pdev)
+{
+	struct ftrtc010_rtc *rtc = platform_get_drvdata(pdev);
+
+	if (!IS_ERR(rtc->extclk))
+		clk_disable_unprepare(rtc->extclk);
+	if (!IS_ERR(rtc->pclk))
+		clk_disable_unprepare(rtc->pclk);
+}
+
+static const struct of_device_id ftrtc010_rtc_dt_match[] = {
+	{ .compatible = "cortina,gemini-rtc" },
+	{ .compatible = "faraday,ftrtc010" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ftrtc010_rtc_dt_match);
+
+static struct platform_driver ftrtc010_rtc_driver = {
+	.driver		= {
+		.name	= DRV_NAME,
+		.of_match_table = ftrtc010_rtc_dt_match,
+	},
+	.probe		= ftrtc010_rtc_probe,
+	.remove		= ftrtc010_rtc_remove,
+};
+
+module_platform_driver_probe(ftrtc010_rtc_driver, ftrtc010_rtc_probe);