1 files changed, 101 insertions, 53 deletions

diff --git a/drivers/thermal/thermal-generic-adc.c b/drivers/thermal/thermal-generic-adc.c
index 73f55d6a1721..7c844589b153 100644
--- a/drivers/thermal/thermal-generic-adc.c
+++ b/drivers/thermal/thermal-generic-adc.c
@@ -1,21 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * 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/iio/iio.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/thermal.h>
 
+#include "thermal_hwmon.h"
+
 struct gadc_thermal_info {
 	struct device *dev;
 	struct thermal_zone_device *tz_dev;
@@ -26,9 +26,12 @@ struct gadc_thermal_info {
 
 static int gadc_thermal_adc_to_temp(struct gadc_thermal_info *gti, int val)
 {
-	int temp, adc_hi, adc_lo;
+	int temp, temp_hi, temp_lo, adc_hi, adc_lo;
 	int i;
 
+	if (!gti->lookup_table)
+		return val;
+
 	for (i = 0; i < gti->nlookup_table; i++) {
 		if (val >= gti->lookup_table[2 * i + 1])
 			break;
@@ -36,50 +39,109 @@ static int gadc_thermal_adc_to_temp(struct gadc_thermal_info *gti, int val)
 
 	if (i == 0) {
 		temp = gti->lookup_table[0];
-	} else if (i >= (gti->nlookup_table - 1)) {
+	} 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 = gti->lookup_table[2 * i];
-		temp -= ((val - adc_lo) * 1000) / (adc_hi - adc_lo);
+
+		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)
+static int gadc_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
 {
-	struct gadc_thermal_info *gti = data;
+	struct gadc_thermal_info *gti = thermal_zone_device_priv(tz);
 	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);
+	if (ret < 0)
 		return ret;
-	}
+
 	*temp = gadc_thermal_adc_to_temp(gti, val);
 
 	return 0;
 }
 
-static const struct thermal_zone_of_device_ops gadc_thermal_ops = {
+static const struct thermal_zone_device_ops gadc_thermal_ops = {
 	.get_temp = gadc_thermal_get_temp,
 };
 
+static const struct iio_chan_spec gadc_thermal_iio_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	}
+};
+
+static int gadc_thermal_read_raw(struct iio_dev *indio_dev,
+				 struct iio_chan_spec const *chan,
+				 int *val, int *val2, long mask)
+{
+	struct gadc_thermal_info *gtinfo = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED:
+		ret = gadc_thermal_get_temp(gtinfo->tz_dev, val);
+		if (ret)
+			return ret;
+
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info gadc_thermal_iio_info = {
+	.read_raw = gadc_thermal_read_raw,
+};
+
+static int gadc_iio_register(struct device *dev, struct gadc_thermal_info *gti)
+{
+	struct gadc_thermal_info *gtinfo;
+	struct iio_dev *indio_dev;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*gtinfo));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	gtinfo = iio_priv(indio_dev);
+	memcpy(gtinfo, gti, sizeof(*gtinfo));
+
+	indio_dev->name = dev_name(dev);
+	indio_dev->info = &gadc_thermal_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = gadc_thermal_iio_channels;
+	indio_dev->num_channels = ARRAY_SIZE(gadc_thermal_iio_channels);
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
 static int gadc_thermal_read_linear_lookup_table(struct device *dev,
 						 struct gadc_thermal_info *gti)
 {
 	struct device_node *np = dev->of_node;
+	enum iio_chan_type chan_type;
 	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 <= 0) {
+		ret = iio_get_channel_type(gti->channel, &chan_type);
+		if (ret || chan_type != IIO_TEMP)
+			dev_notice(dev,
+				   "no lookup table, assuming DAC channel returns milliCelcius\n");
+		return 0;
 	}
 
 	if (ntable % 2) {
@@ -87,8 +149,9 @@ static int gadc_thermal_read_linear_lookup_table(struct device *dev,
 		return -EINVAL;
 	}
 
-	gti->lookup_table = devm_kzalloc(dev, sizeof(*gti->lookup_table) *
-					 ntable, GFP_KERNEL);
+	gti->lookup_table = devm_kcalloc(dev,
+					 ntable, sizeof(*gti->lookup_table),
+					 GFP_KERNEL);
 	if (!gti->lookup_table)
 		return -ENOMEM;
 
@@ -107,57 +170,43 @@ static int gadc_thermal_read_linear_lookup_table(struct device *dev,
 
 static int gadc_thermal_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct gadc_thermal_info *gti;
 	int ret;
 
-	if (!pdev->dev.of_node) {
-		dev_err(&pdev->dev, "Only DT based supported\n");
+	if (!dev->of_node) {
+		dev_err(dev, "Only DT based supported\n");
 		return -ENODEV;
 	}
 
-	gti = devm_kzalloc(&pdev->dev, sizeof(*gti), GFP_KERNEL);
+	gti = devm_kzalloc(dev, sizeof(*gti), GFP_KERNEL);
 	if (!gti)
 		return -ENOMEM;
 
-	ret = gadc_thermal_read_linear_lookup_table(&pdev->dev, gti);
+	gti->channel = devm_iio_channel_get(dev, "sensor-channel");
+	if (IS_ERR(gti->channel))
+		return dev_err_probe(dev, PTR_ERR(gti->channel), "IIO channel not found\n");
+
+	ret = gadc_thermal_read_linear_lookup_table(dev, gti);
 	if (ret < 0)
 		return ret;
 
-	gti->dev = &pdev->dev;
-	platform_set_drvdata(pdev, gti);
+	gti->dev = dev;
 
-	gti->channel = 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 = thermal_zone_of_sensor_register(&pdev->dev, 0,
-						      gti, &gadc_thermal_ops);
+	gti->tz_dev = devm_thermal_of_zone_register(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);
-		goto sensor_fail;
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev,
+				"Thermal zone sensor register failed: %d\n",
+				ret);
+		return ret;
 	}
 
-	return 0;
-
-sensor_fail:
-	iio_channel_release(gti->channel);
+	devm_thermal_add_hwmon_sysfs(dev, gti->tz_dev);
 
-	return ret;
-}
-
-static int gadc_thermal_remove(struct platform_device *pdev)
-{
-	struct gadc_thermal_info *gti = platform_get_drvdata(pdev);
-
-	thermal_zone_of_sensor_unregister(&pdev->dev, gti->tz_dev);
-	iio_channel_release(gti->channel);
-
-	return 0;
+	return gadc_iio_register(&pdev->dev, gti);
 }
 
 static const struct of_device_id of_adc_thermal_match[] = {
@@ -172,7 +221,6 @@ static struct platform_driver gadc_thermal_driver = {
 		.of_match_table = of_adc_thermal_match,
 	},
 	.probe = gadc_thermal_probe,
-	.remove = gadc_thermal_remove,
 };
 
 module_platform_driver(gadc_thermal_driver);