| Message ID | 1391651007-29813-1-git-send-email-courtney.cavin@sonymobile.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Eduardo Valentin |
| Headers | show |
On Wed, 2014-02-05 at 17:43 -0800, Courtney Cavin wrote: > This driver is a generic method for using IIO ADC channels as thermal > sensors. > > Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com> Eduardo, what do you think of this patch? thanks, rui > --- > .../devicetree/bindings/thermal/iio-thermal.txt | 46 +++++ > drivers/thermal/Kconfig | 13 ++ > drivers/thermal/Makefile | 1 + > drivers/thermal/iio_thermal.c | 207 +++++++++++++++++++++ > 4 files changed, 267 insertions(+) > create mode 100644 Documentation/devicetree/bindings/thermal/iio-thermal.txt > create mode 100644 drivers/thermal/iio_thermal.c > > diff --git a/Documentation/devicetree/bindings/thermal/iio-thermal.txt b/Documentation/devicetree/bindings/thermal/iio-thermal.txt > new file mode 100644 > index 0000000..3be11b6 > --- /dev/null > +++ b/Documentation/devicetree/bindings/thermal/iio-thermal.txt > @@ -0,0 +1,46 @@ > +Generic IIO channel thermal sensor bindings > + > +compatible: > + Usage: required > + Type: string > + Desc: compatible string, must be "iio-thermal" > + > +conversion-method: > + Usage: required > + Type: string > + Desc: How to convert IIO voltage values to temperature, one of: > + "interpolation" - interpolate between values in lookup table > + "scalar" - use values as multiplier and divisor > + > +conversion-values: > + Usage: required > + Type: u32 array, 2-tuples > + Desc: lookup table for conversion, for conversion-method: > + "interpolation" - 2-tuples of < uV mK >; micro-volts to > + milli-kelvin; table must ascend > + "scalar" - single scalar 2-tuple as < M D >; where: > + mK = uV * M / D > + > +io-channels: > + Usage: required > + Type: prop-encoded-array > + Desc: See bindings/iio/iio-bindings.txt; must be a voltage channel > + > +Example: > + > +vadc: some_vadc { > + compatible = "..."; > + #io-channel-cells = <1>; > +}; > + > +iio-thermal { > + compatible = "iio-thermal"; > + io-channels = <&vadc 0>; > + conversion-method = "interpolation"; > + conversion-values = < > + 30000 398200 > + 385000 318200 > + 1738000 233200 > + >; > +}; > + > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig > index 35c0664..f83a8e8 100644 > --- a/drivers/thermal/Kconfig > +++ b/drivers/thermal/Kconfig > @@ -114,6 +114,19 @@ config THERMAL_EMULATION > because userland can easily disable the thermal policy by simply > flooding this sysfs node with low temperature values. > > +config IIO_THERMAL > + tristate "Temperature sensor driver for generic IIO channels" > + depends on IIO > + depends on THERMAL_OF > + help > + Support for generic IIO channels, such as ADCs. This driver allows > + you to expose an IIO voltage channel as a thermal sensor. This is > + implemented as a thermal sensor, not a thermal zone, and thus > + requires DT defined thermal infrastructure in order to be useful. > + > + If you aren't sure that you need this support, or haven't configured > + a thermal infrastructure in device tree, you should say 'N' here. > + > config IMX_THERMAL > tristate "Temperature sensor driver for Freescale i.MX SoCs" > depends on CPU_THERMAL > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile > index 54e4ec9..0ee2c92 100644 > --- a/drivers/thermal/Makefile > +++ b/drivers/thermal/Makefile > @@ -25,6 +25,7 @@ obj-y += samsung/ > obj-$(CONFIG_DOVE_THERMAL) += dove_thermal.o > obj-$(CONFIG_DB8500_THERMAL) += db8500_thermal.o > obj-$(CONFIG_ARMADA_THERMAL) += armada_thermal.o > +obj-$(CONFIG_IIO_THERMAL) += iio_thermal.o > obj-$(CONFIG_IMX_THERMAL) += imx_thermal.o > obj-$(CONFIG_DB8500_CPUFREQ_COOLING) += db8500_cpufreq_cooling.o > obj-$(CONFIG_INTEL_POWERCLAMP) += intel_powerclamp.o > diff --git a/drivers/thermal/iio_thermal.c b/drivers/thermal/iio_thermal.c > new file mode 100644 > index 0000000..df21dbc > --- /dev/null > +++ b/drivers/thermal/iio_thermal.c > @@ -0,0 +1,207 @@ > +/* > + * An IIO channel based thermal sensor driver > + * > + * Copyright (C) 2014 Sony Mobile Communications, AB > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; version 2 of the License. > + * > + * This program is distributed in the hope that it will be useful, but > + * WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + * General Public License for more details. > + */ > + > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/iio/iio.h> > +#include <linux/iio/consumer.h> > +#include <linux/thermal.h> > +#include <linux/err.h> > +#include <linux/of.h> > + > +#define MILLIKELVIN_0C 273150 > + > +struct iio_thermal_conv { > + s32 *values; > + int ntuple; > + long (*convert)(const struct iio_thermal_conv *, int val); > +}; > + > +struct iio_thermal { > + struct thermal_zone_device *tz; > + struct iio_channel *chan; > + struct iio_thermal_conv conv; > +}; > + > +static int iio_bsearch(const struct iio_thermal_conv *conv, s32 input) > +{ > + int h = conv->ntuple - 1; > + int l = 0; > + > + while (h - 1 > l) { > + int m = (l + h) & ~1; > + s32 v = conv->values[m]; > + if (v < input) > + l = m >> 1; > + else > + h = m >> 1; > + } > + > + return h; > +} > + > +static long iio_thermal_interpolate(const struct iio_thermal_conv *conv, int v) > +{ > + int n; > + > + n = iio_bsearch(conv, v); > + if (n == 0 || n == conv->ntuple) { > + BUG(); > + } else { > + s32 *pts = &conv->values[(n-1)*2]; > + s32 sx = pts[3] - pts[1]; > + s32 sy = pts[2] - pts[0]; > + return sx * (v - pts[0]) / sy + pts[1]; > + } > +} > + > +static long iio_thermal_scale(const struct iio_thermal_conv *conv, int v) > +{ > + return div_s64((s64)v * conv->values[0], conv->values[1]); > +} > + > +static int iio_thermal_get_temp(void *pdata, long *value) > +{ > + struct iio_thermal *iio = pdata; > + long temp; > + int val; > + int rc; > + > + rc = iio_read_channel_processed(iio->chan, &val); > + if (rc) > + return rc; > + > + temp = iio->conv.convert(&iio->conv, val); > + > + /* thermal core wants milli-celsius; we deal in milli-kelvin */ > + temp = temp - MILLIKELVIN_0C; > + > + /* > + * Although it would appear that the temperature value here is a > + * signed value for sensors, the underlying thermal zone core > + * doesn't deal with negative temperature. Cut this value off at 0C. > + */ > + *value = (temp < 0) ? 0 : temp; > + > + return 0; > +} > + > +static int iio_thermal_probe(struct platform_device *pdev) > +{ > + struct iio_thermal *iio; > + const void *values; > + const char *type; > + int rc; > + > + dev_info(&pdev->dev, "registering IIO thermal device\n"); > + iio = devm_kzalloc(&pdev->dev, sizeof(*iio), GFP_KERNEL); > + if (!iio) > + return -ENOMEM; > + > + values = of_get_property(pdev->dev.of_node, > + "conversion-values", &iio->conv.ntuple); > + if (values == NULL || (iio->conv.ntuple % (sizeof(u32) * 2)) != 0) { > + dev_err(&pdev->dev, "invalid/missing conversion values\n"); > + return -EINVAL; > + } > + iio->conv.ntuple /= sizeof(u32) * 2; > + iio->conv.values = devm_kzalloc(&pdev->dev, > + sizeof(u32) * 2 * iio->conv.ntuple, GFP_KERNEL); > + if (!iio->conv.values) > + return -ENOMEM; > + > + rc = of_property_read_u32_array(pdev->dev.of_node, > + "conversion-values", (u32 *)iio->conv.values, > + iio->conv.ntuple * 2); > + if (rc) { > + dev_err(&pdev->dev, "invalid/missing conversion values\n"); > + return -EINVAL; > + } > + > + rc = of_property_read_string(pdev->dev.of_node, > + "conversion-method", &type); > + if (rc) { > + dev_err(&pdev->dev, "invalid/missing conversion method\n"); > + return rc; > + } > + if (!strcmp(type, "interpolation") && iio->conv.ntuple > 1) { > + if (iio->conv.values[0] > iio->conv.values[2]) { > + dev_err(&pdev->dev, > + "conversion values should ascend\n"); > + return rc; > + } > + iio->conv.convert = iio_thermal_interpolate; > + } else if (!strcmp(type, "scalar") && iio->conv.ntuple == 1) { > + iio->conv.convert = iio_thermal_scale; > + } else { > + dev_err(&pdev->dev, "invalid conversion method for values\n"); > + return rc; > + } > + > + iio->chan = iio_channel_get(&pdev->dev, NULL); > + if (IS_ERR(iio->chan)) { > + dev_err(&pdev->dev, "invalid/missing iio channel\n"); > + return PTR_ERR(iio->chan); > + } > + if (iio->chan->channel->type != IIO_VOLTAGE) { > + dev_err(&pdev->dev, "specified iio channel is not voltage\n"); > + iio_channel_release(iio->chan); > + return -EINVAL; > + } > + platform_set_drvdata(pdev, iio); > + > + iio->tz = thermal_zone_of_sensor_register(&pdev->dev, 0, iio, > + iio_thermal_get_temp, NULL); > + if (IS_ERR(iio->tz)) { > + dev_err(&pdev->dev, "failed to register thermal sensor\n"); > + iio_channel_release(iio->chan); > + return PTR_ERR(iio->tz); > + } > + dev_info(&pdev->dev, "successfully registered IIO thermal sensor\n"); > + > + return 0; > +} > + > +static int iio_thermal_remove(struct platform_device *pdev) > +{ > + struct iio_thermal *iio; > + > + iio = platform_get_drvdata(pdev); > + > + thermal_zone_of_sensor_unregister(&pdev->dev, iio->tz); > + iio_channel_release(iio->chan); > + > + return 0; > +} > + > +static const struct of_device_id iio_thermal_match[] = { > + { .compatible = "iio-thermal", }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, iio_thermal_match); > + > +static struct platform_driver iio_thermal = { > + .driver = { > + .name = "iio-thermal", > + .owner = THIS_MODULE, > + .of_match_table = iio_thermal_match, > + }, > + .probe = iio_thermal_probe, > + .remove = iio_thermal_remove, > +}; > +module_platform_driver(iio_thermal); > + > +MODULE_DESCRIPTION("Thermal driver for IIO ADCs"); > +MODULE_LICENSE("GPL v2"); -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Feb 27, 2014 at 07:53:34AM +0100, Zhang Rui wrote: > On Wed, 2014-02-05 at 17:43 -0800, Courtney Cavin wrote: > > This driver is a generic method for using IIO ADC channels as thermal > > sensors. > > > > Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com> > > Eduardo, > > what do you think of this patch? Apparently not very much. Oh well. Sans further input, I will submit a new series with the following changes: - Fix some return values in probe(). - Change DT binding - Submit as seperate patch in series - Reword/rename to represent a thermistor - Remove specific references to IIO, where appropriate -Courtney -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Mar 14, 2014 at 02:19:53PM -0700, Courtney Cavin wrote: > On Thu, Feb 27, 2014 at 07:53:34AM +0100, Zhang Rui wrote: > > On Wed, 2014-02-05 at 17:43 -0800, Courtney Cavin wrote: > > > This driver is a generic method for using IIO ADC channels as thermal > > > sensors. > > > > > > Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com> > > > > Eduardo, > > > > what do you think of this patch? > > Apparently not very much. Oh well. Curtney, Apolizes, this one fell into the cracks. > > Sans further input, I will submit a new series with the following > changes: > - Fix some return values in probe(). > - Change DT binding > - Submit as seperate patch in series > - Reword/rename to represent a thermistor > - Remove specific references to IIO, where appropriate Do you already send your new version or the current one is still the latest? > > -Courtney > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello, Sorry for the waaay too long answer. In any case, I believe it is worth giving answers to why this patch was not merged. On Wed, Feb 05, 2014 at 05:43:27PM -0800, Courtney Cavin wrote: > This driver is a generic method for using IIO ADC channels as thermal > sensors. In fact, this seams to be a way of getting DT descriptors, introduced in this patches, and register them both in IIO layer and in thermal framework, right? My expectation would be: once it gets registered as IIO device, then it would get registered as thermal zone too. > > Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com> > --- > .../devicetree/bindings/thermal/iio-thermal.txt | 46 +++++ > drivers/thermal/Kconfig | 13 ++ > drivers/thermal/Makefile | 1 + > drivers/thermal/iio_thermal.c | 207 +++++++++++++++++++++ > 4 files changed, 267 insertions(+) > create mode 100644 Documentation/devicetree/bindings/thermal/iio-thermal.txt > create mode 100644 drivers/thermal/iio_thermal.c > > diff --git a/Documentation/devicetree/bindings/thermal/iio-thermal.txt b/Documentation/devicetree/bindings/thermal/iio-thermal.txt > new file mode 100644 > index 0000000..3be11b6 > --- /dev/null > +++ b/Documentation/devicetree/bindings/thermal/iio-thermal.txt > @@ -0,0 +1,46 @@ > +Generic IIO channel thermal sensor bindings > + > +compatible: > + Usage: required > + Type: string > + Desc: compatible string, must be "iio-thermal" > + > +conversion-method: > + Usage: required > + Type: string > + Desc: How to convert IIO voltage values to temperature, one of: > + "interpolation" - interpolate between values in lookup table > + "scalar" - use values as multiplier and divisor > + > +conversion-values: > + Usage: required > + Type: u32 array, 2-tuples > + Desc: lookup table for conversion, for conversion-method: > + "interpolation" - 2-tuples of < uV mK >; micro-volts to > + milli-kelvin; table must ascend > + "scalar" - single scalar 2-tuple as < M D >; where: > + mK = uV * M / D > + > +io-channels: > + Usage: required > + Type: prop-encoded-array > + Desc: See bindings/iio/iio-bindings.txt; must be a voltage channel > + > +Example: > + > +vadc: some_vadc { > + compatible = "..."; > + #io-channel-cells = <1>; > +}; > + > +iio-thermal { > + compatible = "iio-thermal"; > + io-channels = <&vadc 0>; > + conversion-method = "interpolation"; > + conversion-values = < > + 30000 398200 > + 385000 318200 > + 1738000 233200 > + >; > +}; The problem I have with the above is the fact that it is an IIO descriptor, that in turns gets reused to become a thermal zone. The approach leaves the thermal zones with no thermal constraint described. What are the trips? and the cooling maps? > + > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig > index 35c0664..f83a8e8 100644 > --- a/drivers/thermal/Kconfig > +++ b/drivers/thermal/Kconfig > @@ -114,6 +114,19 @@ config THERMAL_EMULATION > because userland can easily disable the thermal policy by simply > flooding this sysfs node with low temperature values. > > +config IIO_THERMAL > + tristate "Temperature sensor driver for generic IIO channels" > + depends on IIO > + depends on THERMAL_OF > + help > + Support for generic IIO channels, such as ADCs. This driver allows > + you to expose an IIO voltage channel as a thermal sensor. This is > + implemented as a thermal sensor, not a thermal zone, and thus > + requires DT defined thermal infrastructure in order to be useful. > + > + If you aren't sure that you need this support, or haven't configured > + a thermal infrastructure in device tree, you should say 'N' here. > + > config IMX_THERMAL > tristate "Temperature sensor driver for Freescale i.MX SoCs" > depends on CPU_THERMAL > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile > index 54e4ec9..0ee2c92 100644 > --- a/drivers/thermal/Makefile > +++ b/drivers/thermal/Makefile > @@ -25,6 +25,7 @@ obj-y += samsung/ > obj-$(CONFIG_DOVE_THERMAL) += dove_thermal.o > obj-$(CONFIG_DB8500_THERMAL) += db8500_thermal.o > obj-$(CONFIG_ARMADA_THERMAL) += armada_thermal.o > +obj-$(CONFIG_IIO_THERMAL) += iio_thermal.o > obj-$(CONFIG_IMX_THERMAL) += imx_thermal.o > obj-$(CONFIG_DB8500_CPUFREQ_COOLING) += db8500_cpufreq_cooling.o > obj-$(CONFIG_INTEL_POWERCLAMP) += intel_powerclamp.o > diff --git a/drivers/thermal/iio_thermal.c b/drivers/thermal/iio_thermal.c > new file mode 100644 > index 0000000..df21dbc > --- /dev/null > +++ b/drivers/thermal/iio_thermal.c > @@ -0,0 +1,207 @@ > +/* > + * An IIO channel based thermal sensor driver > + * > + * Copyright (C) 2014 Sony Mobile Communications, AB > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; version 2 of the License. > + * > + * This program is distributed in the hope that it will be useful, but > + * WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + * General Public License for more details. > + */ > + > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/iio/iio.h> > +#include <linux/iio/consumer.h> > +#include <linux/thermal.h> > +#include <linux/err.h> > +#include <linux/of.h> > + > +#define MILLIKELVIN_0C 273150 > + > +struct iio_thermal_conv { > + s32 *values; > + int ntuple; > + long (*convert)(const struct iio_thermal_conv *, int val); > +}; > + > +struct iio_thermal { > + struct thermal_zone_device *tz; > + struct iio_channel *chan; > + struct iio_thermal_conv conv; > +}; > + > +static int iio_bsearch(const struct iio_thermal_conv *conv, s32 input) > +{ > + int h = conv->ntuple - 1; > + int l = 0; > + > + while (h - 1 > l) { > + int m = (l + h) & ~1; > + s32 v = conv->values[m]; > + if (v < input) > + l = m >> 1; > + else > + h = m >> 1; > + } > + > + return h; > +} > + > +static long iio_thermal_interpolate(const struct iio_thermal_conv *conv, int v) > +{ > + int n; > + > + n = iio_bsearch(conv, v); > + if (n == 0 || n == conv->ntuple) { > + BUG(); > + } else { > + s32 *pts = &conv->values[(n-1)*2]; > + s32 sx = pts[3] - pts[1]; > + s32 sy = pts[2] - pts[0]; > + return sx * (v - pts[0]) / sy + pts[1]; > + } > +} > + > +static long iio_thermal_scale(const struct iio_thermal_conv *conv, int v) > +{ > + return div_s64((s64)v * conv->values[0], conv->values[1]); > +} > + > +static int iio_thermal_get_temp(void *pdata, long *value) > +{ > + struct iio_thermal *iio = pdata; > + long temp; > + int val; > + int rc; > + > + rc = iio_read_channel_processed(iio->chan, &val); > + if (rc) > + return rc; > + > + temp = iio->conv.convert(&iio->conv, val); > + > + /* thermal core wants milli-celsius; we deal in milli-kelvin */ > + temp = temp - MILLIKELVIN_0C; > + > + /* > + * Although it would appear that the temperature value here is a > + * signed value for sensors, the underlying thermal zone core > + * doesn't deal with negative temperature. Cut this value off at 0C. > + */ > + *value = (temp < 0) ? 0 : temp; > + > + return 0; > +} > + > +static int iio_thermal_probe(struct platform_device *pdev) > +{ > + struct iio_thermal *iio; > + const void *values; > + const char *type; > + int rc; > + > + dev_info(&pdev->dev, "registering IIO thermal device\n"); > + iio = devm_kzalloc(&pdev->dev, sizeof(*iio), GFP_KERNEL); > + if (!iio) > + return -ENOMEM; > + > + values = of_get_property(pdev->dev.of_node, > + "conversion-values", &iio->conv.ntuple); > + if (values == NULL || (iio->conv.ntuple % (sizeof(u32) * 2)) != 0) { > + dev_err(&pdev->dev, "invalid/missing conversion values\n"); > + return -EINVAL; > + } > + iio->conv.ntuple /= sizeof(u32) * 2; > + iio->conv.values = devm_kzalloc(&pdev->dev, > + sizeof(u32) * 2 * iio->conv.ntuple, GFP_KERNEL); > + if (!iio->conv.values) > + return -ENOMEM; > + > + rc = of_property_read_u32_array(pdev->dev.of_node, > + "conversion-values", (u32 *)iio->conv.values, > + iio->conv.ntuple * 2); > + if (rc) { > + dev_err(&pdev->dev, "invalid/missing conversion values\n"); > + return -EINVAL; > + } > + > + rc = of_property_read_string(pdev->dev.of_node, > + "conversion-method", &type); > + if (rc) { > + dev_err(&pdev->dev, "invalid/missing conversion method\n"); > + return rc; > + } > + if (!strcmp(type, "interpolation") && iio->conv.ntuple > 1) { > + if (iio->conv.values[0] > iio->conv.values[2]) { > + dev_err(&pdev->dev, > + "conversion values should ascend\n"); > + return rc; > + } > + iio->conv.convert = iio_thermal_interpolate; > + } else if (!strcmp(type, "scalar") && iio->conv.ntuple == 1) { > + iio->conv.convert = iio_thermal_scale; > + } else { > + dev_err(&pdev->dev, "invalid conversion method for values\n"); > + return rc; > + } > + > + iio->chan = iio_channel_get(&pdev->dev, NULL); > + if (IS_ERR(iio->chan)) { > + dev_err(&pdev->dev, "invalid/missing iio channel\n"); > + return PTR_ERR(iio->chan); > + } > + if (iio->chan->channel->type != IIO_VOLTAGE) { > + dev_err(&pdev->dev, "specified iio channel is not voltage\n"); > + iio_channel_release(iio->chan); > + return -EINVAL; > + } > + platform_set_drvdata(pdev, iio); > + > + iio->tz = thermal_zone_of_sensor_register(&pdev->dev, 0, iio, > + iio_thermal_get_temp, NULL); > + if (IS_ERR(iio->tz)) { > + dev_err(&pdev->dev, "failed to register thermal sensor\n"); > + iio_channel_release(iio->chan); > + return PTR_ERR(iio->tz); > + } > + dev_info(&pdev->dev, "successfully registered IIO thermal sensor\n"); > + > + return 0; > +} > + > +static int iio_thermal_remove(struct platform_device *pdev) > +{ > + struct iio_thermal *iio; > + > + iio = platform_get_drvdata(pdev); > + > + thermal_zone_of_sensor_unregister(&pdev->dev, iio->tz); > + iio_channel_release(iio->chan); > + > + return 0; > +} > + > +static const struct of_device_id iio_thermal_match[] = { > + { .compatible = "iio-thermal", }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, iio_thermal_match); > + > +static struct platform_driver iio_thermal = { > + .driver = { > + .name = "iio-thermal", > + .owner = THIS_MODULE, > + .of_match_table = iio_thermal_match, > + }, > + .probe = iio_thermal_probe, > + .remove = iio_thermal_remove, > +}; > +module_platform_driver(iio_thermal); > + > +MODULE_DESCRIPTION("Thermal driver for IIO ADCs"); > +MODULE_LICENSE("GPL v2"); > -- > 1.8.1.5 Please give scripts/checkpatch.pl a try on this patch. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/devicetree/bindings/thermal/iio-thermal.txt b/Documentation/devicetree/bindings/thermal/iio-thermal.txt new file mode 100644 index 0000000..3be11b6 --- /dev/null +++ b/Documentation/devicetree/bindings/thermal/iio-thermal.txt @@ -0,0 +1,46 @@ +Generic IIO channel thermal sensor bindings + +compatible: + Usage: required + Type: string + Desc: compatible string, must be "iio-thermal" + +conversion-method: + Usage: required + Type: string + Desc: How to convert IIO voltage values to temperature, one of: + "interpolation" - interpolate between values in lookup table + "scalar" - use values as multiplier and divisor + +conversion-values: + Usage: required + Type: u32 array, 2-tuples + Desc: lookup table for conversion, for conversion-method: + "interpolation" - 2-tuples of < uV mK >; micro-volts to + milli-kelvin; table must ascend + "scalar" - single scalar 2-tuple as < M D >; where: + mK = uV * M / D + +io-channels: + Usage: required + Type: prop-encoded-array + Desc: See bindings/iio/iio-bindings.txt; must be a voltage channel + +Example: + +vadc: some_vadc { + compatible = "..."; + #io-channel-cells = <1>; +}; + +iio-thermal { + compatible = "iio-thermal"; + io-channels = <&vadc 0>; + conversion-method = "interpolation"; + conversion-values = < + 30000 398200 + 385000 318200 + 1738000 233200 + >; +}; + diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index 35c0664..f83a8e8 100644 --- a/drivers/thermal/Kconfig +++ b/drivers/thermal/Kconfig @@ -114,6 +114,19 @@ config THERMAL_EMULATION because userland can easily disable the thermal policy by simply flooding this sysfs node with low temperature values. +config IIO_THERMAL + tristate "Temperature sensor driver for generic IIO channels" + depends on IIO + depends on THERMAL_OF + help + Support for generic IIO channels, such as ADCs. This driver allows + you to expose an IIO voltage channel as a thermal sensor. This is + implemented as a thermal sensor, not a thermal zone, and thus + requires DT defined thermal infrastructure in order to be useful. + + If you aren't sure that you need this support, or haven't configured + a thermal infrastructure in device tree, you should say 'N' here. + config IMX_THERMAL tristate "Temperature sensor driver for Freescale i.MX SoCs" depends on CPU_THERMAL diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile index 54e4ec9..0ee2c92 100644 --- a/drivers/thermal/Makefile +++ b/drivers/thermal/Makefile @@ -25,6 +25,7 @@ obj-y += samsung/ obj-$(CONFIG_DOVE_THERMAL) += dove_thermal.o obj-$(CONFIG_DB8500_THERMAL) += db8500_thermal.o obj-$(CONFIG_ARMADA_THERMAL) += armada_thermal.o +obj-$(CONFIG_IIO_THERMAL) += iio_thermal.o obj-$(CONFIG_IMX_THERMAL) += imx_thermal.o obj-$(CONFIG_DB8500_CPUFREQ_COOLING) += db8500_cpufreq_cooling.o obj-$(CONFIG_INTEL_POWERCLAMP) += intel_powerclamp.o diff --git a/drivers/thermal/iio_thermal.c b/drivers/thermal/iio_thermal.c new file mode 100644 index 0000000..df21dbc --- /dev/null +++ b/drivers/thermal/iio_thermal.c @@ -0,0 +1,207 @@ +/* + * An IIO channel based thermal sensor driver + * + * Copyright (C) 2014 Sony Mobile Communications, AB + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/iio/iio.h> +#include <linux/iio/consumer.h> +#include <linux/thermal.h> +#include <linux/err.h> +#include <linux/of.h> + +#define MILLIKELVIN_0C 273150 + +struct iio_thermal_conv { + s32 *values; + int ntuple; + long (*convert)(const struct iio_thermal_conv *, int val); +}; + +struct iio_thermal { + struct thermal_zone_device *tz; + struct iio_channel *chan; + struct iio_thermal_conv conv; +}; + +static int iio_bsearch(const struct iio_thermal_conv *conv, s32 input) +{ + int h = conv->ntuple - 1; + int l = 0; + + while (h - 1 > l) { + int m = (l + h) & ~1; + s32 v = conv->values[m]; + if (v < input) + l = m >> 1; + else + h = m >> 1; + } + + return h; +} + +static long iio_thermal_interpolate(const struct iio_thermal_conv *conv, int v) +{ + int n; + + n = iio_bsearch(conv, v); + if (n == 0 || n == conv->ntuple) { + BUG(); + } else { + s32 *pts = &conv->values[(n-1)*2]; + s32 sx = pts[3] - pts[1]; + s32 sy = pts[2] - pts[0]; + return sx * (v - pts[0]) / sy + pts[1]; + } +} + +static long iio_thermal_scale(const struct iio_thermal_conv *conv, int v) +{ + return div_s64((s64)v * conv->values[0], conv->values[1]); +} + +static int iio_thermal_get_temp(void *pdata, long *value) +{ + struct iio_thermal *iio = pdata; + long temp; + int val; + int rc; + + rc = iio_read_channel_processed(iio->chan, &val); + if (rc) + return rc; + + temp = iio->conv.convert(&iio->conv, val); + + /* thermal core wants milli-celsius; we deal in milli-kelvin */ + temp = temp - MILLIKELVIN_0C; + + /* + * Although it would appear that the temperature value here is a + * signed value for sensors, the underlying thermal zone core + * doesn't deal with negative temperature. Cut this value off at 0C. + */ + *value = (temp < 0) ? 0 : temp; + + return 0; +} + +static int iio_thermal_probe(struct platform_device *pdev) +{ + struct iio_thermal *iio; + const void *values; + const char *type; + int rc; + + dev_info(&pdev->dev, "registering IIO thermal device\n"); + iio = devm_kzalloc(&pdev->dev, sizeof(*iio), GFP_KERNEL); + if (!iio) + return -ENOMEM; + + values = of_get_property(pdev->dev.of_node, + "conversion-values", &iio->conv.ntuple); + if (values == NULL || (iio->conv.ntuple % (sizeof(u32) * 2)) != 0) { + dev_err(&pdev->dev, "invalid/missing conversion values\n"); + return -EINVAL; + } + iio->conv.ntuple /= sizeof(u32) * 2; + iio->conv.values = devm_kzalloc(&pdev->dev, + sizeof(u32) * 2 * iio->conv.ntuple, GFP_KERNEL); + if (!iio->conv.values) + return -ENOMEM; + + rc = of_property_read_u32_array(pdev->dev.of_node, + "conversion-values", (u32 *)iio->conv.values, + iio->conv.ntuple * 2); + if (rc) { + dev_err(&pdev->dev, "invalid/missing conversion values\n"); + return -EINVAL; + } + + rc = of_property_read_string(pdev->dev.of_node, + "conversion-method", &type); + if (rc) { + dev_err(&pdev->dev, "invalid/missing conversion method\n"); + return rc; + } + if (!strcmp(type, "interpolation") && iio->conv.ntuple > 1) { + if (iio->conv.values[0] > iio->conv.values[2]) { + dev_err(&pdev->dev, + "conversion values should ascend\n"); + return rc; + } + iio->conv.convert = iio_thermal_interpolate; + } else if (!strcmp(type, "scalar") && iio->conv.ntuple == 1) { + iio->conv.convert = iio_thermal_scale; + } else { + dev_err(&pdev->dev, "invalid conversion method for values\n"); + return rc; + } + + iio->chan = iio_channel_get(&pdev->dev, NULL); + if (IS_ERR(iio->chan)) { + dev_err(&pdev->dev, "invalid/missing iio channel\n"); + return PTR_ERR(iio->chan); + } + if (iio->chan->channel->type != IIO_VOLTAGE) { + dev_err(&pdev->dev, "specified iio channel is not voltage\n"); + iio_channel_release(iio->chan); + return -EINVAL; + } + platform_set_drvdata(pdev, iio); + + iio->tz = thermal_zone_of_sensor_register(&pdev->dev, 0, iio, + iio_thermal_get_temp, NULL); + if (IS_ERR(iio->tz)) { + dev_err(&pdev->dev, "failed to register thermal sensor\n"); + iio_channel_release(iio->chan); + return PTR_ERR(iio->tz); + } + dev_info(&pdev->dev, "successfully registered IIO thermal sensor\n"); + + return 0; +} + +static int iio_thermal_remove(struct platform_device *pdev) +{ + struct iio_thermal *iio; + + iio = platform_get_drvdata(pdev); + + thermal_zone_of_sensor_unregister(&pdev->dev, iio->tz); + iio_channel_release(iio->chan); + + return 0; +} + +static const struct of_device_id iio_thermal_match[] = { + { .compatible = "iio-thermal", }, + { } +}; +MODULE_DEVICE_TABLE(of, iio_thermal_match); + +static struct platform_driver iio_thermal = { + .driver = { + .name = "iio-thermal", + .owner = THIS_MODULE, + .of_match_table = iio_thermal_match, + }, + .probe = iio_thermal_probe, + .remove = iio_thermal_remove, +}; +module_platform_driver(iio_thermal); + +MODULE_DESCRIPTION("Thermal driver for IIO ADCs"); +MODULE_LICENSE("GPL v2");
This driver is a generic method for using IIO ADC channels as thermal sensors. Signed-off-by: Courtney Cavin <courtney.cavin@sonymobile.com> --- .../devicetree/bindings/thermal/iio-thermal.txt | 46 +++++ drivers/thermal/Kconfig | 13 ++ drivers/thermal/Makefile | 1 + drivers/thermal/iio_thermal.c | 207 +++++++++++++++++++++ 4 files changed, 267 insertions(+) create mode 100644 Documentation/devicetree/bindings/thermal/iio-thermal.txt create mode 100644 drivers/thermal/iio_thermal.c