1 files changed, 331 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-hid-sensor-time.c b/drivers/rtc/rtc-hid-sensor-time.c
new file mode 100644
index 000000000..16fdefafe
--- /dev/null
+++ b/drivers/rtc/rtc-hid-sensor-time.c
@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * HID Sensor Time Driver
+ * Copyright (c) 2012, Alexander Holler.
+ */
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/hid-sensor-hub.h>
+#include <linux/iio/iio.h>
+#include <linux/rtc.h>
+
+enum hid_time_channel {
+	CHANNEL_SCAN_INDEX_YEAR,
+	CHANNEL_SCAN_INDEX_MONTH,
+	CHANNEL_SCAN_INDEX_DAY,
+	CHANNEL_SCAN_INDEX_HOUR,
+	CHANNEL_SCAN_INDEX_MINUTE,
+	CHANNEL_SCAN_INDEX_SECOND,
+	TIME_RTC_CHANNEL_MAX,
+};
+
+struct hid_time_state {
+	struct hid_sensor_hub_callbacks callbacks;
+	struct hid_sensor_common common_attributes;
+	struct hid_sensor_hub_attribute_info info[TIME_RTC_CHANNEL_MAX];
+	struct rtc_time last_time;
+	spinlock_t lock_last_time;
+	struct completion comp_last_time;
+	struct rtc_time time_buf;
+	struct rtc_device *rtc;
+};
+
+static const u32 hid_time_addresses[TIME_RTC_CHANNEL_MAX] = {
+	HID_USAGE_SENSOR_TIME_YEAR,
+	HID_USAGE_SENSOR_TIME_MONTH,
+	HID_USAGE_SENSOR_TIME_DAY,
+	HID_USAGE_SENSOR_TIME_HOUR,
+	HID_USAGE_SENSOR_TIME_MINUTE,
+	HID_USAGE_SENSOR_TIME_SECOND,
+};
+
+/* Channel names for verbose error messages */
+static const char * const hid_time_channel_names[TIME_RTC_CHANNEL_MAX] = {
+	"year", "month", "day", "hour", "minute", "second",
+};
+
+/* Callback handler to send event after all samples are received and captured */
+static int hid_time_proc_event(struct hid_sensor_hub_device *hsdev,
+				unsigned usage_id, void *priv)
+{
+	unsigned long flags;
+	struct hid_time_state *time_state = platform_get_drvdata(priv);
+
+	spin_lock_irqsave(&time_state->lock_last_time, flags);
+	time_state->last_time = time_state->time_buf;
+	spin_unlock_irqrestore(&time_state->lock_last_time, flags);
+	complete(&time_state->comp_last_time);
+	return 0;
+}
+
+static u32 hid_time_value(size_t raw_len, char *raw_data)
+{
+	switch (raw_len) {
+	case 1:
+		return *(u8 *)raw_data;
+	case 2:
+		return *(u16 *)raw_data;
+	case 4:
+		return *(u32 *)raw_data;
+	default:
+		return (u32)(~0U); /* 0xff... or -1 to denote an error */
+	}
+}
+
+static int hid_time_capture_sample(struct hid_sensor_hub_device *hsdev,
+				unsigned usage_id, size_t raw_len,
+				char *raw_data, void *priv)
+{
+	struct hid_time_state *time_state = platform_get_drvdata(priv);
+	struct rtc_time *time_buf = &time_state->time_buf;
+
+	switch (usage_id) {
+	case HID_USAGE_SENSOR_TIME_YEAR:
+		/*
+		 * The draft for HID-sensors (HUTRR39) currently doesn't define
+		 * the range for the year attribute. Therefor we support
+		 * 8 bit (0-99) and 16 or 32 bits (full) as size for the year.
+		 */
+		if (raw_len == 1) {
+			time_buf->tm_year = *(u8 *)raw_data;
+			if (time_buf->tm_year < 70)
+				/* assume we are in 1970...2069 */
+				time_buf->tm_year += 100;
+		} else
+			time_buf->tm_year =
+				(int)hid_time_value(raw_len, raw_data)-1900;
+		break;
+	case HID_USAGE_SENSOR_TIME_MONTH:
+		/* sensors are sending the month as 1-12, we need 0-11 */
+		time_buf->tm_mon = (int)hid_time_value(raw_len, raw_data)-1;
+		break;
+	case HID_USAGE_SENSOR_TIME_DAY:
+		time_buf->tm_mday = (int)hid_time_value(raw_len, raw_data);
+		break;
+	case HID_USAGE_SENSOR_TIME_HOUR:
+		time_buf->tm_hour = (int)hid_time_value(raw_len, raw_data);
+		break;
+	case HID_USAGE_SENSOR_TIME_MINUTE:
+		time_buf->tm_min = (int)hid_time_value(raw_len, raw_data);
+		break;
+	case HID_USAGE_SENSOR_TIME_SECOND:
+		time_buf->tm_sec = (int)hid_time_value(raw_len, raw_data);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/* small helper, haven't found any other way */
+static const char *hid_time_attrib_name(u32 attrib_id)
+{
+	static const char unknown[] = "unknown";
+	unsigned i;
+
+	for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
+		if (hid_time_addresses[i] == attrib_id)
+			return hid_time_channel_names[i];
+	}
+	return unknown; /* should never happen */
+}
+
+static int hid_time_parse_report(struct platform_device *pdev,
+				struct hid_sensor_hub_device *hsdev,
+				unsigned usage_id,
+				struct hid_time_state *time_state)
+{
+	int report_id, i;
+
+	for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i)
+		if (sensor_hub_input_get_attribute_info(hsdev,
+				HID_INPUT_REPORT, usage_id,
+				hid_time_addresses[i],
+				&time_state->info[i]) < 0)
+			return -EINVAL;
+	/* Check the (needed) attributes for sanity */
+	report_id = time_state->info[0].report_id;
+	if (report_id < 0) {
+		dev_err(&pdev->dev, "bad report ID!\n");
+		return -EINVAL;
+	}
+	for (i = 0; i < TIME_RTC_CHANNEL_MAX; ++i) {
+		if (time_state->info[i].report_id != report_id) {
+			dev_err(&pdev->dev,
+				"not all needed attributes inside the same report!\n");
+			return -EINVAL;
+		}
+		if (time_state->info[i].size == 3 ||
+				time_state->info[i].size > 4) {
+			dev_err(&pdev->dev,
+				"attribute '%s' not 8, 16 or 32 bits wide!\n",
+				hid_time_attrib_name(
+					time_state->info[i].attrib_id));
+			return -EINVAL;
+		}
+		if (time_state->info[i].units !=
+				HID_USAGE_SENSOR_UNITS_NOT_SPECIFIED &&
+				/* allow attribute seconds with unit seconds */
+				!(time_state->info[i].attrib_id ==
+				HID_USAGE_SENSOR_TIME_SECOND &&
+				time_state->info[i].units ==
+				HID_USAGE_SENSOR_UNITS_SECOND)) {
+			dev_err(&pdev->dev,
+				"attribute '%s' hasn't a unit of type 'none'!\n",
+				hid_time_attrib_name(
+					time_state->info[i].attrib_id));
+			return -EINVAL;
+		}
+		if (time_state->info[i].unit_expo) {
+			dev_err(&pdev->dev,
+				"attribute '%s' hasn't a unit exponent of 1!\n",
+				hid_time_attrib_name(
+					time_state->info[i].attrib_id));
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int hid_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	unsigned long flags;
+	struct hid_time_state *time_state = dev_get_drvdata(dev);
+	int ret;
+
+	reinit_completion(&time_state->comp_last_time);
+	/* get a report with all values through requesting one value */
+	sensor_hub_input_attr_get_raw_value(time_state->common_attributes.hsdev,
+			HID_USAGE_SENSOR_TIME, hid_time_addresses[0],
+			time_state->info[0].report_id, SENSOR_HUB_SYNC, false);
+	/* wait for all values (event) */
+	ret = wait_for_completion_killable_timeout(
+			&time_state->comp_last_time, HZ*6);
+	if (ret > 0) {
+		/* no error */
+		spin_lock_irqsave(&time_state->lock_last_time, flags);
+		*tm = time_state->last_time;
+		spin_unlock_irqrestore(&time_state->lock_last_time, flags);
+		return 0;
+	}
+	if (!ret)
+		return -EIO; /* timeouted */
+	return ret; /* killed (-ERESTARTSYS) */
+}
+
+static const struct rtc_class_ops hid_time_rtc_ops = {
+	.read_time = hid_rtc_read_time,
+};
+
+static int hid_time_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
+	struct hid_time_state *time_state = devm_kzalloc(&pdev->dev,
+		sizeof(struct hid_time_state), GFP_KERNEL);
+
+	if (time_state == NULL)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, time_state);
+
+	spin_lock_init(&time_state->lock_last_time);
+	init_completion(&time_state->comp_last_time);
+	time_state->common_attributes.hsdev = hsdev;
+	time_state->common_attributes.pdev = pdev;
+
+	ret = hid_sensor_parse_common_attributes(hsdev,
+				HID_USAGE_SENSOR_TIME,
+				&time_state->common_attributes,
+				NULL,
+				0);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to setup common attributes!\n");
+		return ret;
+	}
+
+	ret = hid_time_parse_report(pdev, hsdev, HID_USAGE_SENSOR_TIME,
+					time_state);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to setup attributes!\n");
+		return ret;
+	}
+
+	time_state->callbacks.send_event = hid_time_proc_event;
+	time_state->callbacks.capture_sample = hid_time_capture_sample;
+	time_state->callbacks.pdev = pdev;
+	ret = sensor_hub_register_callback(hsdev, HID_USAGE_SENSOR_TIME,
+					&time_state->callbacks);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "register callback failed!\n");
+		return ret;
+	}
+
+	ret = sensor_hub_device_open(hsdev);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to open sensor hub device!\n");
+		goto err_open;
+	}
+
+	/*
+	 * Enable HID input processing early in order to be able to read the
+	 * clock already in devm_rtc_device_register().
+	 */
+	hid_device_io_start(hsdev->hdev);
+
+	time_state->rtc = devm_rtc_device_register(&pdev->dev,
+					"hid-sensor-time", &hid_time_rtc_ops,
+					THIS_MODULE);
+
+	if (IS_ERR(time_state->rtc)) {
+		hid_device_io_stop(hsdev->hdev);
+		ret = PTR_ERR(time_state->rtc);
+		time_state->rtc = NULL;
+		dev_err(&pdev->dev, "rtc device register failed!\n");
+		goto err_rtc;
+	}
+
+	return ret;
+
+err_rtc:
+	sensor_hub_device_close(hsdev);
+err_open:
+	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
+	return ret;
+}
+
+static int hid_time_remove(struct platform_device *pdev)
+{
+	struct hid_sensor_hub_device *hsdev = dev_get_platdata(&pdev->dev);
+
+	sensor_hub_device_close(hsdev);
+	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_TIME);
+
+	return 0;
+}
+
+static const struct platform_device_id hid_time_ids[] = {
+	{
+		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
+		.name = "HID-SENSOR-2000a0",
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, hid_time_ids);
+
+static struct platform_driver hid_time_platform_driver = {
+	.id_table = hid_time_ids,
+	.driver = {
+		.name	= KBUILD_MODNAME,
+	},
+	.probe		= hid_time_probe,
+	.remove		= hid_time_remove,
+};
+module_platform_driver(hid_time_platform_driver);
+
+MODULE_DESCRIPTION("HID Sensor Time");
+MODULE_AUTHOR("Alexander Holler <holler@ahsoftware.de>");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(IIO_HID);