/* * Generic ADC thermal driver * * Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved. * * Author: Laxman Dewangan * * 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 #include #include #include #include #include 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, 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 - 1)) { 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); } 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_kzalloc(dev, sizeof(*gti->lookup_table) * ntable, 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 = 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); 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; } return 0; sensor_fail: iio_channel_release(gti->channel); 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; } 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, .remove = gadc_thermal_remove, }; module_platform_driver(gadc_thermal_driver); MODULE_AUTHOR("Laxman Dewangan "); MODULE_DESCRIPTION("Generic ADC thermal driver using IIO framework with DT"); MODULE_LICENSE("GPL v2"); e='35'>35space:mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-25 14:30:04 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-25 14:30:04 -0800
commit3ddc76dfc786cc6f87852693227fb0b1f124f807 (patch)
tree8192b4721e05cf6823087f9696db8c0c8f144b02 /sound/firewire/amdtp-am824.h
parentb272f732f888d4cf43c943a40c9aaa836f9b7431 (diff)
parent1f3a8e49d8f28f498b8694464623ac20aebfe62a (diff)
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer type cleanups from Thomas Gleixner: "This series does a tree wide cleanup of types related to timers/timekeeping. - Get rid of cycles_t and use a plain u64. The type is not really helpful and caused more confusion than clarity - Get rid of the ktime union. The union has become useless as we use the scalar nanoseconds storage unconditionally now. The 32bit timespec alike storage got removed due to the Y2038 limitations some time ago. That leaves the odd union access around for no reason. Clean it up. Both changes have been done with coccinelle and a small amount of manual mopping up" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: ktime: Get rid of ktime_equal() ktime: Cleanup ktime_set() usage ktime: Get rid of the union clocksource: Use a plain u64 instead of cycle_t
Diffstat (limited to 'sound/firewire/amdtp-am824.h')