Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932604AbbHCV0Q (ORCPT ); Mon, 3 Aug 2015 17:26:16 -0400 Received: from ns.pmeerw.net ([84.19.176.92]:39778 "EHLO pmeerw.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932360AbbHCV0P (ORCPT ); Mon, 3 Aug 2015 17:26:15 -0400 Date: Mon, 3 Aug 2015 23:26:12 +0200 (CEST) From: Peter Meerwald To: Matt Porter cc: Linux IIO List , Jonathan Cameron , Linux Kernel Mailing List Subject: Re: [PATCH 2/3] iio: temperature: add max6675 thermocouple converter driver In-Reply-To: <1438635410-3757-3-git-send-email-mporter@konsulko.com> Message-ID: References: <1438635410-3757-1-git-send-email-mporter@konsulko.com> <1438635410-3757-3-git-send-email-mporter@konsulko.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6315 Lines: 238 On Mon, 3 Aug 2015, Matt Porter wrote: > Add a driver for the MAX6675 thermocouple converter. This > device interfaces with K-type thermocouples and provides > cold-junction compensated temperature readings via a > SPI interface. comments below > Signed-off-by: Matt Porter > --- > drivers/iio/temperature/Kconfig | 11 +++ > drivers/iio/temperature/Makefile | 1 + > drivers/iio/temperature/max6675.c | 155 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 167 insertions(+) > create mode 100644 drivers/iio/temperature/max6675.c > > diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig > index 21feaa4..b73fbf4 100644 > --- a/drivers/iio/temperature/Kconfig > +++ b/drivers/iio/temperature/Kconfig > @@ -3,6 +3,17 @@ > # > menu "Temperature sensors" > > +config MAX6675 > + tristate "MAX6675 thermocouple converter" > + depends on SPI > + help > + If you say yes here you get support for the Maxim > + MAX6675 thermocouple converter connected with SPI. > + > + This driver can also be built as a module. If so, the module will > + be called max6675. > + extra newline > + > config MLX90614 > tristate "MLX90614 contact-less infrared sensor" > depends on I2C > diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile > index 40710a8..d67ef40 100644 > --- a/drivers/iio/temperature/Makefile > +++ b/drivers/iio/temperature/Makefile > @@ -2,5 +2,6 @@ > # Makefile for industrial I/O temperature drivers > # > > +obj-$(CONFIG_MAX6675) += max6675.o > obj-$(CONFIG_MLX90614) += mlx90614.o > obj-$(CONFIG_TMP006) += tmp006.o > diff --git a/drivers/iio/temperature/max6675.c b/drivers/iio/temperature/max6675.c > new file mode 100644 > index 0000000..2d1fda2 > --- /dev/null > +++ b/drivers/iio/temperature/max6675.c > @@ -0,0 +1,155 @@ > +/* > + * max6675.c - MAX6675 thermocouple converter driver > + * > + * Copyright (C) 2015 Konsulko Group, Matt Porter > + * > + * 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; either version 2 of the License, or > + * (at your option) any later version. > + * > + * 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 > +#include > +#include > +#include > +#include > +#include > + > +struct max6675_state { > + struct spi_device *spi; > +}; > + > +static const struct iio_chan_spec max6675_channels[] = { > + { > + .type = IIO_TEMP, > + .info_mask_separate = > + BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE), > + }, > +}; > + > +static int max6675_read(struct max6675_state *st, int *val) > +{ > + int ret; > + > + ret = spi_read(st->spi, val, 2); > + if (ret < 0) > + return ret; > + > + /* Temperature is bits 14..3 */ > + *val = (*val >> 3) & 0xfff; what about endianness conversion? use be16_to_cpu() > + > + return ret; > +} > + > +static int max6675_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, > + int *val2, > + long m) > +{ > + struct max6675_state *st = iio_priv(indio_dev); > + int ret; > + > + if (m == IIO_CHAN_INFO_RAW) { > + *val2 = 0; no need to set *val2 to 0 when returning VAL_INT > + ret = max6675_read(st, val); > + if (ret) > + return ret; > + } else if (m == IIO_CHAN_INFO_SCALE) { > + *val = 250; > + *val2 = 0; > + } else > + return -EINVAL; > + > + return IIO_VAL_INT; > +} > + > +static const struct iio_info max6675_info = { > + .driver_module = THIS_MODULE, > + .read_raw = &max6675_read_raw, > +}; > + > +static int max6675_probe(struct spi_device *spi) > +{ > + struct iio_dev *indio_dev; > + struct max6675_state *st; > + int ret = 0; no need to initialize ret > + > + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); > + if (!indio_dev) > + return -ENOMEM; > + > + st = iio_priv(indio_dev); > + st->spi = spi; > + > + spi->mode = SPI_MODE_1; > + spi->bits_per_word = 16; > + > + spi_set_drvdata(spi, indio_dev); > + > + indio_dev->dev.parent = &spi->dev; > + indio_dev->name = spi_get_device_id(spi)->name; > + indio_dev->channels = max6675_channels; > + indio_dev->num_channels = ARRAY_SIZE(max6675_channels); > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->info = &max6675_info; > + > + ret = iio_device_register(indio_dev); devm_ and drop _remove() > + if (ret < 0) > + dev_err(&spi->dev, "unable to register device\n"); > + > + return ret; > +} > + > +static int max6675_remove(struct spi_device *spi) > +{ > + struct iio_dev *indio_dev = spi_get_drvdata(spi); > + > + iio_device_unregister(indio_dev); > + > + return 0; > +} > + > +static const struct acpi_device_id max6675_acpi_ids[] = { > + { "MXIM6675", 0 }, > + {}, > +}; > +MODULE_DEVICE_TABLE(acpi, max6675_acpi_ids); > + > +static const struct of_device_id max6675_dt_ids[] = { > + { .compatible = "maxim,max6675" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, max6675_dt_ids); > + > +static const struct spi_device_id max6675_spi_ids[] = { > + {"max6675", 0}, > + {}, > +}; > +MODULE_DEVICE_TABLE(spi, max6675_spi_ids); > + > +static struct spi_driver max6675_driver = { > + .driver = { > + .name = "max6675", > + .owner = THIS_MODULE, > + .acpi_match_table = ACPI_PTR(max6675_acpi_ids), > + .of_match_table = of_match_ptr(max6675_dt_ids), > + }, > + .probe = max6675_probe, > + .remove = max6675_remove, > + .id_table = max6675_spi_ids, > +}; > +module_spi_driver(max6675_driver); > + > +MODULE_AUTHOR("Matt Porter "); > +MODULE_DESCRIPTION("MAX6675 thermocouple converter driver"); > +MODULE_LICENSE("GPL"); > +MODULE_ALIAS("spi:max6675"); > -- Peter Meerwald +43-664-2444418 (mobile) -- 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/