Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 171 insertions, 0 deletions

diff --git a/drivers/thermal/thermal-generic-adc.c b/drivers/thermal/thermal-generic-adc.c
new file mode 100644
index 000000000..e22fc60ad
--- /dev/null
+++ b/drivers/thermal/thermal-generic-adc.c
@@ -0,0 +1,171 @@
+/*
+ * Generic ADC thermal driver
+ *
+ * Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved.
+ *
+ * Author: Laxman Dewangan <ldewangan@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/iio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/thermal.h>
+
+struct gadc_thermal_info {
+	struct device *dev;
+	struct thermal_zone_device *tz_dev;
+	struct iio_channel *channel;
+	s32 *lookup_table;
+	int nlookup_table;
+};
+
+static int gadc_thermal_adc_to_temp(struct gadc_thermal_info *gti, int val)
+{
+	int temp, temp_hi, temp_lo, adc_hi, adc_lo;
+	int i;
+
+	for (i = 0; i < gti->nlookup_table; i++) {
+		if (val >= gti->lookup_table[2 * i + 1])
+			break;
+	}
+
+	if (i == 0) {
+		temp = gti->lookup_table[0];
+	} else if (i >= gti->nlookup_table) {
+		temp = gti->lookup_table[2 * (gti->nlookup_table - 1)];
+	} else {
+		adc_hi = gti->lookup_table[2 * i - 1];
+		adc_lo = gti->lookup_table[2 * i + 1];
+
+		temp_hi = gti->lookup_table[2 * i - 2];
+		temp_lo = gti->lookup_table[2 * i];
+
+		temp = temp_hi + mult_frac(temp_lo - temp_hi, val - adc_hi,
+					   adc_lo - adc_hi);
+	}
+
+	return temp;
+}
+
+static int gadc_thermal_get_temp(void *data, int *temp)
+{
+	struct gadc_thermal_info *gti = data;
+	int val;
+	int ret;
+
+	ret = iio_read_channel_processed(gti->channel, &val);
+	if (ret < 0) {
+		dev_err(gti->dev, "IIO channel read failed %d\n", ret);
+		return ret;
+	}
+	*temp = gadc_thermal_adc_to_temp(gti, val);
+
+	return 0;
+}
+
+static const struct thermal_zone_of_device_ops gadc_thermal_ops = {
+	.get_temp = gadc_thermal_get_temp,
+};
+
+static int gadc_thermal_read_linear_lookup_table(struct device *dev,
+						 struct gadc_thermal_info *gti)
+{
+	struct device_node *np = dev->of_node;
+	int ntable;
+	int ret;
+
+	ntable = of_property_count_elems_of_size(np, "temperature-lookup-table",
+						 sizeof(u32));
+	if (ntable < 0) {
+		dev_err(dev, "Lookup table is not provided\n");
+		return ntable;
+	}
+
+	if (ntable % 2) {
+		dev_err(dev, "Pair of temperature vs ADC read value missing\n");
+		return -EINVAL;
+	}
+
+	gti->lookup_table = devm_kcalloc(dev,
+					 ntable, sizeof(*gti->lookup_table),
+					 GFP_KERNEL);
+	if (!gti->lookup_table)
+		return -ENOMEM;
+
+	ret = of_property_read_u32_array(np, "temperature-lookup-table",
+					 (u32 *)gti->lookup_table, ntable);
+	if (ret < 0) {
+		dev_err(dev, "Failed to read temperature lookup table: %d\n",
+			ret);
+		return ret;
+	}
+
+	gti->nlookup_table = ntable / 2;
+
+	return 0;
+}
+
+static int gadc_thermal_probe(struct platform_device *pdev)
+{
+	struct gadc_thermal_info *gti;
+	int ret;
+
+	if (!pdev->dev.of_node) {
+		dev_err(&pdev->dev, "Only DT based supported\n");
+		return -ENODEV;
+	}
+
+	gti = devm_kzalloc(&pdev->dev, sizeof(*gti), GFP_KERNEL);
+	if (!gti)
+		return -ENOMEM;
+
+	ret = gadc_thermal_read_linear_lookup_table(&pdev->dev, gti);
+	if (ret < 0)
+		return ret;
+
+	gti->dev = &pdev->dev;
+	platform_set_drvdata(pdev, gti);
+
+	gti->channel = devm_iio_channel_get(&pdev->dev, "sensor-channel");
+	if (IS_ERR(gti->channel)) {
+		ret = PTR_ERR(gti->channel);
+		dev_err(&pdev->dev, "IIO channel not found: %d\n", ret);
+		return ret;
+	}
+
+	gti->tz_dev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, gti,
+							   &gadc_thermal_ops);
+	if (IS_ERR(gti->tz_dev)) {
+		ret = PTR_ERR(gti->tz_dev);
+		dev_err(&pdev->dev, "Thermal zone sensor register failed: %d\n",
+			ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id of_adc_thermal_match[] = {
+	{ .compatible = "generic-adc-thermal", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, of_adc_thermal_match);
+
+static struct platform_driver gadc_thermal_driver = {
+	.driver = {
+		.name = "generic-adc-thermal",
+		.of_match_table = of_adc_thermal_match,
+	},
+	.probe = gadc_thermal_probe,
+};
+
+module_platform_driver(gadc_thermal_driver);
+
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
+MODULE_DESCRIPTION("Generic ADC thermal driver using IIO framework with DT");
+MODULE_LICENSE("GPL v2");