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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/thermal/thermal-generic-adc.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/thermal/thermal-generic-adc.c')
-rw-r--r--drivers/thermal/thermal-generic-adc.c180
1 files changed, 180 insertions, 0 deletions
diff --git a/drivers/thermal/thermal-generic-adc.c b/drivers/thermal/thermal-generic-adc.c
new file mode 100644
index 0000000000..1717e4a19d
--- /dev/null
+++ b/drivers/thermal/thermal-generic-adc.c
@@ -0,0 +1,180 @@
+// 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>
+ */
+#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>
+
+#include "thermal_hwmon.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;
+
+ if (!gti->lookup_table)
+ return val;
+
+ 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(struct thermal_zone_device *tz, int *temp)
+{
+ 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)
+ return ret;
+
+ *temp = gadc_thermal_adc_to_temp(gti, val);
+
+ return 0;
+}
+
+static const struct thermal_zone_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;
+ 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) {
+ 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) {
+ 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;
+
+ gti->channel = devm_iio_channel_get(&pdev->dev, "sensor-channel");
+ if (IS_ERR(gti->channel)) {
+ ret = PTR_ERR(gti->channel);
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "IIO channel not found: %d\n", ret);
+ return ret;
+ }
+
+ ret = gadc_thermal_read_linear_lookup_table(&pdev->dev, gti);
+ if (ret < 0)
+ return ret;
+
+ gti->dev = &pdev->dev;
+
+ gti->tz_dev = devm_thermal_of_zone_register(&pdev->dev, 0, gti,
+ &gadc_thermal_ops);
+ if (IS_ERR(gti->tz_dev)) {
+ ret = PTR_ERR(gti->tz_dev);
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev,
+ "Thermal zone sensor register failed: %d\n",
+ ret);
+ return ret;
+ }
+
+ devm_thermal_add_hwmon_sysfs(&pdev->dev, gti->tz_dev);
+
+ 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");