/* * 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"); '>includemode:
authorIago Abal <mail@iagoabal.eu>2017-01-11 14:00:21 +0100
committerVinod Koul <vinod.koul@intel.com>2017-01-25 15:35:11 +0530
commit91539eb1fda2d530d3b268eef542c5414e54bf1a (patch)
tree960f5ca6342ad20837aff18aad6e8ecd7da32fd6 /net/tipc/addr.h
parent6610d0edf6dc7ee97e46ab3a538a565c79d26199 (diff)
dmaengine: pl330: fix double lock
The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the following double-lock bug: Double lock: 1. spin_lock_irqsave(pch->lock, flags) at pl330_free_chan_resources:2236; 2. call to function `pl330_release_channel' immediately after; 3. call to function `dma_pl330_rqcb' in line 1753; 4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505. I have fixed it as suggested by Marek Szyprowski. First, I have replaced `pch->lock' with `pl330->lock' in functions `pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids the double-lock by acquiring a different lock than `dma_pl330_rqcb'. NOTE that, as a result, `pl330_free_chan_resources' executes `list_splice_tail_init' on `pch->work_list' under lock `pl330->lock', whereas in the rest of the code `pch->work_list' is protected by `pch->lock'. I don't know if this may cause race conditions. Similarly `pch->cyclic' is written by `pl330_alloc_chan_resources' under `pl330->lock' but read by `pl330_tx_submit' under `pch->lock'. Second, I have removed locking from `pl330_request_channel' and `pl330_release_channel' functions. Function `pl330_request_channel' is only called from `pl330_alloc_chan_resources', so the lock is already held. Function `pl330_release_channel' is called from `pl330_free_chan_resources', which already holds the lock, and from `pl330_del'. Function `pl330_del' is called in an error path of `pl330_probe' and at the end of `pl330_remove', but I assume that there cannot be concurrent accesses to the protected data at those points. Signed-off-by: Iago Abal <mail@iagoabal.eu> Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'net/tipc/addr.h')