From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 54DDEC54EEB for ; Sat, 21 Mar 2020 18:00:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2DA4B20775 for ; Sat, 21 Mar 2020 18:00:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584813637; bh=R8/k/BHsiTKtFiHeVg6oqqD4t3VG097MC+PCLtg3FJE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=F9eQQS+EghfdTRldgLicm3/a2cl+x+Cgw9JBwiC8nYaPjB6yFFBCytfIWUpM2mhRM K9kclm3OOajvcJgNHUeujQGosCNQSyBqpy//1nOwHUa+I/0oa8rimXE2t6rh7r/tIp AdiYR+tGx1+/RqSyURnu8tQcGPDUX3NUplaNT7d4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728018AbgCUSAe (ORCPT ); Sat, 21 Mar 2020 14:00:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:55862 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727599AbgCUSAP (ORCPT ); Sat, 21 Mar 2020 14:00:15 -0400 Received: from archlinux (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0972B20663; Sat, 21 Mar 2020 18:00:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584813614; bh=R8/k/BHsiTKtFiHeVg6oqqD4t3VG097MC+PCLtg3FJE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=m+U6oaNZA5UYoY4rJqTPNLEmJ42fmCfjYHKSRRG7sEupHoOfdWwVNJeGJhn1XRUMD xNrE9GsOdeOr9tFB5Wboij+EN7NXerigRJs/4OjpTpWy+ucW7Q9jz/PIs+lGEBZZIx uMOfjBn7TvSF5eyW1+oEpRhltO7g2avGwexLBw/I= Date: Sat, 21 Mar 2020 18:00:09 +0000 From: Jonathan Cameron To: Alexandru Lazar Cc: linux-iio@vger.kernel.org, devicetree@vger.kernel.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, robh+dt@kernel.org, mark.rutland@arm.com, Alexandru Ardelean Subject: Re: [PATCH v4 2/2] iio: adc: Add MAX1241 driver Message-ID: <20200321180009.10939fd5@archlinux> In-Reply-To: <20200320150114.9297-3-alazar@startmail.com> References: <20200320150114.9297-1-alazar@startmail.com> <20200320150114.9297-3-alazar@startmail.com> X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Fri, 20 Mar 2020 17:01:15 +0200 Alexandru Lazar wrote: > Add driver for the Maxim MAX1241 12-bit, single-channel ADC. The driver > includes support for this device's low-power operation mode. > > Reviewed-by: Alexandru Ardelean > Signed-off-by: Alexandru Lazar Few minor things inline, but looks good in general. > --- > drivers/iio/adc/Kconfig | 10 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/max1241.c | 206 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 217 insertions(+) > create mode 100644 drivers/iio/adc/max1241.c > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 5d8540b7b427..55f6462cd93f 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -566,6 +566,16 @@ config MAX1118 > To compile this driver as a module, choose M here: the module will be > called max1118. > > +config MAX1241 > + tristate "Maxim max1241 ADC driver" > + depends on SPI_MASTER > + help > + Say yes here to build support for Maxim max1241 12-bit, single-channel > + ADC. > + > + To compile this driver as a module, choose M here: the module will be > + called max1241. > + > config MAX1363 > tristate "Maxim max1363 ADC driver" > depends on I2C > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index a1f1fbec0f87..37d6f17559dc 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -54,6 +54,7 @@ obj-$(CONFIG_LTC2497) += ltc2497.o > obj-$(CONFIG_MAX1027) += max1027.o > obj-$(CONFIG_MAX11100) += max11100.o > obj-$(CONFIG_MAX1118) += max1118.o > +obj-$(CONFIG_MAX1241) += max1241.o > obj-$(CONFIG_MAX1363) += max1363.o > obj-$(CONFIG_MAX9611) += max9611.o > obj-$(CONFIG_MCP320X) += mcp320x.o > diff --git a/drivers/iio/adc/max1241.c b/drivers/iio/adc/max1241.c > new file mode 100644 > index 000000000000..0278510ec346 > --- /dev/null > +++ b/drivers/iio/adc/max1241.c > @@ -0,0 +1,206 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * MAX1241 low-power, 12-bit serial ADC > + * > + * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf > + */ > + > +#include Nitpick; Tidy up ordering of headers. If no other reason to have a particular order go with alphabetical. > +#include > +#include > +#include > +#include > +#include > + > +#define MAX1241_VAL_MASK 0xFFF > +#define MAX1241_SHDN_DELAY_USEC 4 > + > +enum max1241_id { > + max1241, > +}; > + > +struct max1241 { > + struct spi_device *spi; > + struct mutex lock; > + struct regulator *reg; > + struct gpio_desc *shdn; > + > + __be16 data ____cacheline_aligned; > +}; > + > +static const struct iio_chan_spec max1241_channels[] = { > + { > + .type = IIO_VOLTAGE, > + .indexed = 1, > + .channel = 0, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE), > + .scan_index = 0, > + .scan_type = { > + .sign = 'u', > + .realbits = 12, > + .storagebits = 16, > + }, No need to specify scan_index or scan_type unless the driver supports buffered modes. Nothing will use them until then. > + }, > +}; > + > +static int max1241_read(struct max1241 *adc) > +{ > + struct spi_transfer xfers[] = { > + /* > + * Begin conversion by bringing /CS low for at least > + * tconv us. > + */ > + { > + .len = 0, > + .delay.value = 8, > + .delay.unit = SPI_DELAY_UNIT_USECS, > + }, > + /* > + * Then read two bytes of data in our RX buffer. > + */ > + { > + .rx_buf = &adc->data, > + .len = 2, > + }, > + }; > + > + return spi_sync_transfer(adc->spi, xfers, ARRAY_SIZE(xfers)); > +} > + > +static int max1241_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + int ret, vref_uV; > + struct max1241 *adc = iio_priv(indio_dev); > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + mutex_lock(&adc->lock); > + > + if (adc->shdn) { > + gpiod_set_value(adc->shdn, 0); > + udelay(MAX1241_SHDN_DELAY_USEC); > + } > + > + ret = max1241_read(adc); > + > + if (adc->shdn) > + gpiod_set_value(adc->shdn, 1); > + > + if (ret) { > + mutex_unlock(&adc->lock); > + return ret; > + } > + > + *val = (be16_to_cpu(adc->data) >> 3) & MAX1241_VAL_MASK; > + > + mutex_unlock(&adc->lock); > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + vref_uV = regulator_get_voltage(adc->reg); > + > + if (vref_uV < 0) > + return vref_uV; > + > + *val = vref_uV / 1000; > + *val2 = 12; > + > + return IIO_VAL_FRACTIONAL_LOG2; > + default: > + return -EINVAL; > + } > +} > + > +static const struct iio_info max1241_info = { > + .read_raw = max1241_read_raw, > +}; > + > +static void max1241_disable_reg_action(void *data) > +{ > + struct max1241 *adc = data; > + int err; > + > + err = regulator_disable(adc->reg); > + if (err) > + dev_err(&adc->spi->dev, "could not disable reference regulator.\n"); > +} > + > +static int max1241_probe(struct spi_device *spi) > +{ > + struct iio_dev *indio_dev; > + struct max1241 *adc; > + int ret = 0; Looks like ret is always set in all the paths that can use it. Hence no need to initialize here. > + > + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc)); > + if (!indio_dev) > + return -ENOMEM; > + > + adc = iio_priv(indio_dev); > + adc->spi = spi; > + mutex_init(&adc->lock); > + > + spi_set_drvdata(spi, indio_dev); > + > + adc->reg = devm_regulator_get(&spi->dev, "vref"); > + if (IS_ERR(adc->reg)) { > + dev_err(&spi->dev, "failed to get vref regulator\n"); > + return PTR_ERR(adc->reg); > + } > + > + ret = regulator_enable(adc->reg); > + if (ret) > + return ret; > + > + ret = devm_add_action_or_reset(&spi->dev, max1241_disable_reg_action, > + adc); > + if (ret) { > + dev_err(&spi->dev, "could not set up regulator cleanup action!\n"); > + return ret; > + } > + > + adc->shdn = devm_gpiod_get_optional(&spi->dev, "shdn", GPIOD_OUT_HIGH); > + > + if (IS_ERR(adc->shdn)) > + return PTR_ERR(adc->shdn); > + > + if (!adc->shdn) > + dev_dbg(&spi->dev, "no shdn pin passed, low-power mode disabled"); > + else > + dev_dbg(&spi->dev, "shdn pin passed, low-power mode enabled"); > + > + indio_dev->name = spi_get_device_id(spi)->name; > + indio_dev->dev.parent = &spi->dev; > + indio_dev->info = &max1241_info; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = max1241_channels; > + indio_dev->num_channels = ARRAY_SIZE(max1241_channels); > + > + return devm_iio_device_register(&spi->dev, indio_dev); > +} > + > +static const struct spi_device_id max1241_id[] = { > + { "max1241", max1241 }, > + {}, > +}; > + > +static const struct of_device_id max1241_dt_ids[] = { > + { .compatible = "maxim,max1241" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, max1241_dt_ids); > + > +static struct spi_driver max1241_spi_driver = { > + .driver = { > + .name = "max1241", > + .of_match_table = max1241_dt_ids, > + }, > + .probe = max1241_probe, > + .id_table = max1241_id, > +}; > +module_spi_driver(max1241_spi_driver); > + > +MODULE_AUTHOR("Alexandru Lazar "); > +MODULE_DESCRIPTION("MAX1241 ADC driver"); > +MODULE_LICENSE("GPL v2");