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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS 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 9119AC282CE for ; Mon, 11 Feb 2019 21:27:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 337F1217D9 for ; Mon, 11 Feb 2019 21:27:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549920464; bh=SNMZzBcWgf9AKAa1BBsX7uRw+g7gYkfsUnuR2656jm8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=aM2dK8ERYNf2KUHCxuOR9HfXKu7IPGrun2PniG5tZTkbDAX8Go98iq4FXB4p9sAPJ /N/J55qYnxk8OCwqXGFlVnT4eqDshM2czPwoKzHwFEoxHI8PYkLWVXG9y0DkCulo/j ahg8Al3bapLuTUkqVEWLGw1kZ7PFewhDbqoZSCxw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727602AbfBKV1m (ORCPT ); Mon, 11 Feb 2019 16:27:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:34136 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726228AbfBKV1l (ORCPT ); Mon, 11 Feb 2019 16:27:41 -0500 Received: from archlinux (cpc91196-cmbg18-2-0-cust659.5-4.cable.virginm.net [81.96.234.148]) (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 CF26420823; Mon, 11 Feb 2019 21:27:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549920459; bh=SNMZzBcWgf9AKAa1BBsX7uRw+g7gYkfsUnuR2656jm8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=xIk3M/NvoclAYnCjOmXCVWG5YMcdH0SPmLkc4nXj+p7e3sixmB+QR+1GxEQPawhom DSk4BTpXQ2S3oD8BFBweQ5bBOapdpT/wroa69AIz/k6QaWqU6iLWiUe6W188KevQwB n1OB2VIkqDXO41q3ZzMF7QwE1XK1o4Rii5lS8ab4= Date: Mon, 11 Feb 2019 21:27:34 +0000 From: Jonathan Cameron To: Sven Van Asbroeck Cc: Robert Eshleman , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Linux Kernel Mailing List , linux-iio@vger.kernel.org Subject: Re: [PATCH 1/3] iio: light: Add driver for ap3216c Message-ID: <20190211212734.01909e62@archlinux> In-Reply-To: References: <89716a4433cd83aea5f4200359b184b0ee2cc8bd.1549828313.git.bobbyeshleman@gmail.com> X-Mailer: Claws Mail 3.17.3 (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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 11 Feb 2019 14:09:12 -0500 Sven Van Asbroeck wrote: > Hi Robert, > > On Sun, Feb 10, 2019 at 3:39 PM Robert Eshleman wrote: > > > > This patch adds support for the ap3216c ambient light and proximity > > sensor. > > Comments below. > Follow up inline... Mostly looks good to me, but a few places to tidy up. Thanks, Jonathan > > > > Supported features include: > > > > * Illuminance (lux) > > * Proximity (raw) > > * IR (raw) > > * Rising/falling threshold events for illuminance and proximity > > * Calibration scale for illuminance > > * Calibration bias for proximity > > > > Signed-off-by: Robert Eshleman > > --- > > drivers/iio/light/Kconfig | 11 + > > drivers/iio/light/Makefile | 1 + > > drivers/iio/light/ap3216c.c | 793 ++++++++++++++++++++++++++++++++++++ > > 3 files changed, 805 insertions(+) > > create mode 100644 drivers/iio/light/ap3216c.c > > > > diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig > > index 36f458433480..74688d19beb1 100644 > > --- a/drivers/iio/light/Kconfig > > +++ b/drivers/iio/light/Kconfig > > @@ -41,6 +41,17 @@ config AL3320A > > To compile this driver as a module, choose M here: the > > module will be called al3320a. > > > > +config AP3216C > > + tristate "AP3216C Ambient Light and Proximity sensor" > > + select REGMAP_I2C > > + depends on I2C > > + help > > + Say Y here to build a driver for the AP3216C Ambient Light and > > + Proximity sensor. > > + > > + To compile this driver as a module, choose M here: the > > + module will be called ap3216c. > > + > > config APDS9300 > > tristate "APDS9300 ambient light sensor" > > depends on I2C > > diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile > > index 286bf3975372..7d2f8fa0f30d 100644 > > --- a/drivers/iio/light/Makefile > > +++ b/drivers/iio/light/Makefile > > @@ -7,6 +7,7 @@ > > obj-$(CONFIG_ACPI_ALS) += acpi-als.o > > obj-$(CONFIG_ADJD_S311) += adjd_s311.o > > obj-$(CONFIG_AL3320A) += al3320a.o > > +obj-$(CONFIG_AP3216C) += ap3216c.o > > obj-$(CONFIG_APDS9300) += apds9300.o > > obj-$(CONFIG_APDS9960) += apds9960.o > > obj-$(CONFIG_BH1750) += bh1750.o > > diff --git a/drivers/iio/light/ap3216c.c b/drivers/iio/light/ap3216c.c > > new file mode 100644 > > index 000000000000..12802b45c01c > > --- /dev/null > > +++ b/drivers/iio/light/ap3216c.c > > @@ -0,0 +1,793 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * AP3216C Ambient Light and Infrared Proximity Sensor > > + * > > + * Copyright (c) 2019, Robert Eshleman. > > + * > > + * Datasheet: https://pdf-datasheet-datasheet.netdna-ssl.com/pdf-down/A/P/3/AP3216C-LITE-ON.pdf > > + * > > + * 7-bit I2C slave address 0x1E > > + */ > > + > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +#define AP3216C_DRV_NAME "ap3216c" > > + > > +/* register addresses */ > > +#define AP3216C_SYS 0x0 > > +#define AP3216C_INT_STATUS 0x01 > > +#define AP3216C_INT_CLR 0x02 > > +#define AP3216C_IR_DATA_LO 0x0A > > +#define AP3216C_IR_DATA_HI 0x0B > > +#define AP3216C_ALS_DATA_LO 0x0C > > +#define AP3216C_ALS_DATA_HI 0x0D > > +#define AP3216C_PS_DATA_LO 0x0E > > +#define AP3216C_PS_DATA_HI 0x0F > > +#define AP3216C_ALS_CFG 0x10 > > +#define AP3216C_ALS_CALIB 0x19 > > +#define AP3216C_ALS_LO_THR_LO 0x1A > > +#define AP3216C_ALS_LO_THR_HI 0x1B > > +#define AP3216C_ALS_HI_THR_LO 0x1C > > +#define AP3216C_ALS_HI_THR_HI 0x1D > > +#define AP3216C_PS_CFG 0x20 > > +#define AP3216C_PS_CALIB_LO 0x28 > > +#define AP3216C_PS_CALIB_HI 0x29 > > +#define AP3216C_PS_LO_THR_LO 0x2A > > +#define AP3216C_PS_LO_THR_HI 0x2B > > +#define AP3216C_PS_HI_THR_LO 0x2C > > +#define AP3216C_PS_HI_THR_HI 0x2D > > + > > +/* SYS_MODE mask and config value */ > > +#define AP3216C_SYS_MODE_ALS_PS GENMASK(1, 0) > > +#define AP3216C_SYS_MODE_ALS_ONLY 0x01 > > + > > +/* INT_STATUS masks and config value */ > > +#define AP3216C_INT_STATUS_ALS_MASK 1 > > +#define AP3216C_INT_STATUS_PS_MASK (1 << 1) > > +#define AP3216C_INT_STATUS_CLR GENMASK(1, 0) > > +#define AP3216C_INT_CLR_MANUAL 1 > > + > > +/* IR_DATA mask/shift */ > > +#define AP3216C_IR_DATA_LO_MASK GENMASK(1, 0) > > +#define AP3216C_IR_DATA_HI_SHIFT 2 > > + > > +/* ALS_DATA shift and fractional helper */ > > +#define AP3216C_ALS_DATA_HI_SHIFT 8 > > +#define AP3216C_ALS_DATA_DENOM 100000 > > + > > +/* ALS_CALIB masks/shifts */ > > +#define AP3216C_ALS_CALIB_INT_MASK GENMASK(7, 6) > > +#define AP3216C_ALS_CALIB_INT_SHIFT 6 > > +#define AP3216C_ALS_CALIB_DEC_MASK GENMASK(5, 0) > > + > > +/* PS_DATA shifts/masks/bits */ > > +#define AP3216C_PS_DATA_LO_MASK GENMASK(3, 0) > > +#define AP3216C_PS_DATA_LO_IR_OF BIT(6) > > +#define AP3216C_PS_DATA_HI_MASK GENMASK(5, 0) > > +#define AP3216C_PS_DATA_HI_SHIFT 4 > > +#define AP3216C_PS_DATA_HI_IR_OF BIT(6) > > + > > +/* ALS_CFG masks */ > > +#define AP3216C_ALS_CFG_GAIN_MASK GENMASK(5, 4) > > + > > +/* ALS_CALIB shifts */ > > +#define AP3216C_ALS_CALIB_INT_SHIFT 6 > > + > > +/* ALS_HI_THR masks and shifts */ > > +#define AP3216C_ALS_HI_THR_LO_MASK GENMASK(7, 0) > > +#define AP3216C_ALS_HI_THR_HI_SHIFT 8 > > +#define AP3216C_ALS_HI_THR_HI_MASK GENMASK(7, 4) > > +#define AP3216C_ALS_HI_THR_HI_SHIFT 8 > > + > > +/* ALS_LO_THR masks and shifts */ > > +#define AP3216C_ALS_LO_THR_LO_MASK GENMASK(3, 0) > > +#define AP3216C_ALS_LO_THR_HI_MASK GENMASK(7, 4) > > +#define AP3216C_ALS_LO_THR_HI_SHIFT 8 > > + > > +/* PS_CFG reg mask/shift/bit values */ > > +#define AP3216C_PS_CFG_GAIN_MASK GENMASK(3, 2) > > +#define AP3216C_PS_CFG_GAIN_SHIFT 2 > > +#define AP3216C_PS_CFG_GAIN(val) \ > > + (1 << ((val & AP3216C_PS_CFG_GAIN_MASK) >> AP3216C_PS_CFG_GAIN_SHIFT)) > > + > > +/* PS_LO and PS_HI shift/mask and multiplier values */ > > +#define AP3216C_PS_LO_THR_HI_MULT 4 > > +#define AP3216C_PS_HI_THR_HI_SHIFT 2 > > +#define AP3216C_PS_HI_THR_HI_MULT 4 > > + > > +/* PS_THR_LO and PS_THR_HI masks */ > > +#define AP3216C_PS_THR_LO_MASK GENMASK(1, 0) > > +#define AP3216C_PS_THR_HI_MASK GENMASK(10, 2) > > + > > +/* PS_CALIB_HI and PS_CALIB_LO shift/mask/bit values */ > > +#define AP3216C_PS_CALIB_HI_SHIFT 1 > > +#define AP3216C_PS_CALIB_HI_MASK GENMASK(8, 1) > > +#define AP3216C_PS_CALIB_LO_MASK BIT(0) > > + > > +/* ALS fractional helper values */ > > +#define AP3216C_ALS_INTEG_MULT 10000 > > +#define AP3216C_ALS_FRACT_DIV 100 > > + > > +/* ALS_CALIB min/max values (0.0 <= ALS_CALIB <= 3.984375) */ > > +#define AP3216C_ALS_CALIB_INT_MIN 0 > > +#define AP3216C_ALS_CALIB_DEC_MIN 0 > > +#define AP3216C_ALS_CALIB_INT_MAX 3 > > +#define AP3216C_ALS_CALIB_DEC_MAX 984375 > > + > > +/* ALS_CALIB conversion denominator */ > > +#define AP3216C_ALS_CALIB_DENOM 64 > > + > > +#define AP3216C_IIO_MULT 1000000 > > + > > +static u16 ap3216c_gain_array[] = { > > + 3500, /* 0.3500 lux resolution */ > > + 788, /* 0.0788 lux resolution */ > > + 197, /* 0.0197 lux resolution */ > > + 49, /* 0.0049 lux resolution */ > > +}; > > + > > +struct ap3216c_data { > > + struct regmap *regmap; > > + struct i2c_client *client; > > + bool als_thresh_en; > > + bool prox_thresh_en; > > +}; > > + > > +static const struct iio_event_spec ap3216c_event_spec[] = { > > + { > > + .type = IIO_EV_TYPE_THRESH, > > + .dir = IIO_EV_DIR_RISING, > > + .mask_separate = BIT(IIO_EV_INFO_VALUE), > > + }, > > + { > > + .type = IIO_EV_TYPE_THRESH, > > + .dir = IIO_EV_DIR_FALLING, > > + .mask_separate = BIT(IIO_EV_INFO_VALUE), > > + }, > > + { > > + .type = IIO_EV_TYPE_THRESH, > > + .dir = IIO_EV_DIR_EITHER, > > + .mask_shared_by_type = BIT(IIO_EV_INFO_ENABLE), > > + }, > > +}; > > + > > +static const struct iio_chan_spec ap3216c_channels[] = { > > + { > > + .type = IIO_LIGHT, > > + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | > > + BIT(IIO_CHAN_INFO_CALIBSCALE), > > + .event_spec = ap3216c_event_spec, > > + .num_event_specs = ARRAY_SIZE(ap3216c_event_spec), > > + }, > > + { > > + .type = IIO_PROXIMITY, > > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > > + BIT(IIO_CHAN_INFO_CALIBBIAS), > > + .event_spec = ap3216c_event_spec, > > + .num_event_specs = ARRAY_SIZE(ap3216c_event_spec), > > + }, > > + { > > + .type = IIO_LIGHT, > > + .modified = 1, > > + .channel2 = IIO_MOD_LIGHT_IR, > > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > > + } > > +}; > > + > > +static int ap3216c_write_event_value(struct iio_dev *indio_dev, > > + const struct iio_chan_spec *chan, > > + enum iio_event_type type, > > + enum iio_event_direction dir, > > + enum iio_event_info info, > > + int val, int val2) > > +{ > > + struct ap3216c_data *data = iio_priv(indio_dev); > > + int cfg, gain; > > + int integral, fractional; > > + int lo, hi; > > + u16 thr; > > + int ret; > > + > > + switch (chan->type) { > > + case IIO_LIGHT: > > + ret = regmap_read(data->regmap, AP3216C_ALS_CFG, &cfg); > > + if (ret < 0) > > + return ret; > > + > > + gain = ap3216c_gain_array[cfg & AP3216C_ALS_CFG_GAIN_MASK]; > > + integral = val * AP3216C_ALS_INTEG_MULT / gain; > > + fractional = val2 / AP3216C_ALS_FRACT_DIV / gain; > > + > > + thr = integral + fractional; > > + > > + switch (dir) { > > + case IIO_EV_DIR_RISING: > > + ret = regmap_write(data->regmap, AP3216C_ALS_HI_THR_LO, > > + thr & AP3216C_ALS_HI_THR_LO_MASK); > > + if (ret < 0) > > + return ret; > > + > > + ret = regmap_write(data->regmap, > > + AP3216C_ALS_HI_THR_HI, > > + (thr & AP3216C_ALS_HI_THR_HI_MASK) >> > > + AP3216C_ALS_HI_THR_HI_SHIFT); > > + if (ret < 0) > > + return ret; > > + > > + return ret; > > + > > + case IIO_EV_DIR_FALLING: > > + ret = regmap_write(data->regmap, > > + AP3216C_ALS_LO_THR_LO, > > + thr & AP3216C_ALS_LO_THR_LO_MASK); > > + > > + if (ret < 0) > > + return ret; > > + > > + ret = regmap_write(data->regmap, > > + AP3216C_ALS_LO_THR_HI, > > + (thr & AP3216C_ALS_LO_THR_HI_MASK) >> > > + AP3216C_ALS_LO_THR_HI_SHIFT); > > + if (ret < 0) > > + return ret; > > + > > + return ret; > > + > > + default: > > + return -EINVAL; > > + } > > + return -EINVAL; > > + > > + case IIO_PROXIMITY: > > + lo = val & AP3216C_PS_THR_LO_MASK; > > + hi = (val & AP3216C_PS_THR_HI_MASK) >> > > + AP3216C_PS_HI_THR_HI_SHIFT; > > + > > + switch (dir) { > > + case IIO_EV_DIR_RISING: > > + ret = regmap_write(data->regmap, > > + AP3216C_PS_HI_THR_LO, lo); > > + if (ret < 0) > > + return ret; > > + > > + return regmap_write(data->regmap, > > + AP3216C_PS_HI_THR_HI, hi); > > + > > + case IIO_EV_DIR_FALLING: > > + ret = regmap_write(data->regmap, > > + AP3216C_PS_LO_THR_LO, lo); > > + if (ret < 0) > > + return ret; > > + > > + return regmap_write(data->regmap, > > + AP3216C_PS_LO_THR_HI, hi); > > + > > + default: > > + return -EINVAL; > > + } > > + > > + default: > > + return -EINVAL; > > + } > > + return -EINVAL; > > +} > > + > > +static int ap3216c_read_event_value(struct iio_dev *indio_dev, > > + const struct iio_chan_spec *chan, > > + enum iio_event_type type, > > + enum iio_event_direction dir, > > + enum iio_event_info info, > > + int *val, int *val2) > > +{ > > + struct ap3216c_data *data = iio_priv(indio_dev); > > + unsigned int lo, hi; > > + int ret; > > + > > + switch (chan->type) { > > + case IIO_LIGHT: > > + switch (dir) { > > + case IIO_EV_DIR_RISING: > > + ret = regmap_read(data->regmap, > > + AP3216C_ALS_HI_THR_LO, &lo); > > + if (ret < 0) > > + return ret; > > + > > + ret = regmap_read(data->regmap, > > + AP3216C_ALS_HI_THR_HI, &hi); > > + if (ret < 0) > > + return ret; > > + > > + *val = (hi << AP3216C_ALS_HI_THR_HI_SHIFT) | lo; > > + return IIO_VAL_INT; > > + > > + case IIO_EV_DIR_FALLING: > > + ret = regmap_read(data->regmap, > > + AP3216C_ALS_LO_THR_LO, &lo); > > + if (ret < 0) > > + return ret; > > + > > + ret = regmap_read(data->regmap, > > + AP3216C_ALS_LO_THR_HI, &hi); > > + if (ret < 0) > > + return ret; > > + > > + *val = (hi << AP3216C_ALS_LO_THR_HI_SHIFT) | lo; > > + return IIO_VAL_INT; > > + > > + default: > > + return -EINVAL; > > + } > > + > > + case IIO_PROXIMITY: > > + switch (dir) { > > + case IIO_EV_DIR_RISING: > > + ret = regmap_read(data->regmap, > > + AP3216C_PS_HI_THR_LO, &lo); > > + if (ret < 0) > > + return ret; > > + > > + ret = regmap_read(data->regmap, > > + AP3216C_PS_HI_THR_HI, &hi); > > + if (ret < 0) > > + return ret; > > + > > + *val = (hi * AP3216C_PS_HI_THR_HI_MULT) + > > + (lo & AP3216C_PS_THR_LO_MASK); > > + > > + return IIO_VAL_INT; > > + > > + case IIO_EV_DIR_FALLING: > > + ret = regmap_read(data->regmap, > > + AP3216C_PS_LO_THR_LO, &lo); > > + if (ret < 0) > > + return ret; > > + > > + ret = regmap_read(data->regmap, > > + AP3216C_PS_LO_THR_HI, &hi); > > Does the iio core serialize access to this function? It doesn't. > If so, disregard this comment. > > If this function can be executed concurrently by multiple threads, > then the read to _LO and _HI needs to be serialized. Otherwise > you could end up reading nonsense values. > > Datasheet says that when _LO is read, _HI is latched into a > temporary register. So imagine two threads reading out the value > concurrently: > > Chip performs a conversion (call it 1) > Thread A reads _LO (1), chip stores _HI(1), thread pauses > The chip performs a new conversion (call it 2) > Thread B reads _LO (2), chip stores _HI(2) > Thread A wakes, reads _HI (2) > > So now thread A has a _LO from conversion (1), and a _HI from > conversion (2) !! > > I think you could solve this by placing a mutex around the two > reads, but see my comment below. Agreed. Or potentially just use regmap_bulk_read and rely on the regmap internal locking to do it for you. > > > + if (ret < 0) > > + return ret; > > + > > + *val = (hi * AP3216C_PS_LO_THR_HI_MULT) + > > + (lo & AP3216C_PS_THR_LO_MASK); > > + > > + return IIO_VAL_INT; > > + > > + default: > > + return -EINVAL; > > + } > > + > > + default: > > + return -EINVAL; > > + } > > + > > + return -EINVAL; > > +} > > + > > +static int ap3216c_read_event_config(struct iio_dev *indio_dev, > > + const struct iio_chan_spec *chan, > > + enum iio_event_type type, > > + enum iio_event_direction dir) > > +{ > > + struct ap3216c_data *data = iio_priv(indio_dev); > > + > > + switch (chan->type) { > > + case IIO_LIGHT: > > + return data->als_thresh_en; > > + > > + case IIO_PROXIMITY: > > + return data->prox_thresh_en; > > + > > + default: > > + return -EINVAL; > > + } > > + > > + return -EINVAL; > > +} > > + > > +static int ap3216c_write_event_config(struct iio_dev *indio_dev, > > + const struct iio_chan_spec *chan, > > + enum iio_event_type type, > > + enum iio_event_direction dir, int state) > > +{ > > + struct ap3216c_data *data = iio_priv(indio_dev); > > + > > + switch (chan->type) { > > + case IIO_LIGHT: > > + data->als_thresh_en = state; > > + return 0; > > + > > + case IIO_PROXIMITY: > > + data->prox_thresh_en = state; > > + return 0; > > + > > + default: > > + return -EINVAL; > > + } > > + > > + return -EINVAL; > > +} > > + > > +static const struct regmap_config ap3216c_regmap_config = { > > + .reg_bits = 8, > > + .val_bits = 8, > > + .max_register = AP3216C_PS_HI_THR_HI, > > +}; > > + > > +/** > > + * Returns integral part of decimal between 0.0 and 3.984275 > > + */ > > +static int ap3216c_als_calibscale_int(int val) > > +{ > > + if (val > AP3216C_ALS_CALIB_INT_MAX) > > + return AP3216C_ALS_CALIB_INT_MAX; > > + > > + if (val <= AP3216C_ALS_CALIB_INT_MIN) > > + return AP3216C_ALS_CALIB_INT_MIN; > > + > > + return val; > > +} > > + > > +/** > > + * Returns decimal part of decimal number between 0.0 and 3.984275 > > + */ > > +static int ap3216c_als_calibscale_dec(int val, int val2) > > +{ > > + /* Return max decimal if number exceeds calibscale max */ > > + if (val > AP3216C_ALS_CALIB_INT_MAX || > > + (val == AP3216C_ALS_CALIB_INT_MAX && > > + val2 > AP3216C_ALS_CALIB_DEC_MAX)) > > + return AP3216C_ALS_CALIB_DEC_MAX; > > + > > + /* Floor the decimal if integral below minimum */ > > + if (val <= AP3216C_ALS_CALIB_INT_MIN) > > + return AP3216C_ALS_CALIB_DEC_MIN; > > + > > + /* Floor the decimal if decimal below minimum */ > > + if (val2 < AP3216C_ALS_CALIB_DEC_MIN) > > + return AP3216C_ALS_CALIB_DEC_MIN; > > + > > + /* Return max decimal if decimal above maximum */ > > + if (val2 > AP3216C_ALS_CALIB_DEC_MAX) > > + return AP3216C_ALS_CALIB_DEC_MAX; > > + > > + return val2; > > +} > > + > > +static int ap3216c_write_raw(struct iio_dev *indio_dev, > > + struct iio_chan_spec const *chan, > > + int val, int val2, long mask) > > +{ > > + struct ap3216c_data *data = iio_priv(indio_dev); > > + int integral, decimal; > > + int tmp; > > + int ret; > > + > > + switch (mask) { > > + case IIO_CHAN_INFO_CALIBSCALE: > > + switch (chan->type) { > > + case IIO_LIGHT: > > + integral = ap3216c_als_calibscale_int(val); > > + decimal = ap3216c_als_calibscale_dec(val, val2); > > + > > + tmp = integral << AP3216C_ALS_CALIB_INT_SHIFT; > > + > > + /* > > + * Reverse scaling by multiplying by the scaling > > + * denominator and dividing by IIO multiplier. > > + */ > > + tmp |= (decimal * AP3216C_ALS_CALIB_DENOM) / > > + AP3216C_IIO_MULT; > > + > > + return regmap_write(data->regmap, > > + AP3216C_ALS_CALIB, tmp); > > + > > + default: > > + return -EINVAL; > > + } > > + > > + case IIO_CHAN_INFO_CALIBBIAS: > > + switch (chan->type) { > > + case IIO_PROXIMITY: > > + ret = regmap_write(data->regmap, AP3216C_PS_CALIB_LO, > > + val & AP3216C_PS_CALIB_LO_MASK); > > + if (ret < 0) > > + return ret; > > + > > + tmp = (val & AP3216C_PS_CALIB_HI_MASK) >> > > + AP3216C_PS_CALIB_HI_SHIFT; regmap_bulk_write perhaps? > > + > > + return regmap_write(data->regmap, > > + AP3216C_PS_CALIB_HI, tmp); > > + > > + default: > > + return -EINVAL; > > + } > > + default: > > + return -EINVAL; > > + } This final return should be unneeded. > > + return -EINVAL; > > +} > > + > > +static int ap3216c_read_raw(struct iio_dev *indio_dev, > > + struct iio_chan_spec const *chan, > > + int *val, int *val2, long mask) > > +{ > > + struct ap3216c_data *data = iio_priv(indio_dev); > > + int lo, hi; > > + int cfg, tmp; > > + int ret; > > + > > + switch (mask) { > > + case IIO_CHAN_INFO_CALIBSCALE: > > + switch (chan->type) { > > + case IIO_LIGHT: > > + ret = regmap_read(data->regmap, > > + AP3216C_ALS_CALIB, &tmp); > > + if (ret < 0) > > + return ret; > > + > > + /* Scale is multiplied by 1/64 */ > > + *val = tmp; > > + *val2 = AP3216C_ALS_CALIB_DENOM; > > + return IIO_VAL_FRACTIONAL; > > + > > + default: > > + return -EINVAL; > > + } > > + > > + case IIO_CHAN_INFO_CALIBBIAS: > > + switch (chan->type) { > > + case IIO_PROXIMITY: regmap_read_bulk should get you both in one call with concurrency protection as an added bonus. > > + ret = regmap_read(data->regmap, > > + AP3216C_PS_CALIB_LO, &lo); > > + if (ret < 0) > > + return ret; > > + > > + ret = regmap_read(data->regmap, > > + AP3216C_PS_CALIB_HI, &hi); > > + if (ret < 0) > > + return ret; > > + > > + > > + *val = lo | (hi << AP3216C_PS_CALIB_HI_SHIFT); lo should probably be masked. Bits are documented as reserved, not 0 as far as I can see. > > + return IIO_VAL_INT; > > + > > + default: > > + return -EINVAL; > > + } > > + > > + case IIO_CHAN_INFO_PROCESSED: > > + switch (chan->type) { > > + case IIO_LIGHT: > > + ret = regmap_read(data->regmap, > > + AP3216C_ALS_DATA_LO, &lo); > > + if (ret < 0) > > + return ret; > > + > > + ret = regmap_read(data->regmap, > > + AP3216C_ALS_DATA_HI, &hi); > > + if (ret < 0) > > + return ret; > > + > > + ret = regmap_read(data->regmap, > > + AP3216C_ALS_CFG, &cfg); > > + if (ret < 0) > > + return ret; > > + > > + tmp = (hi << AP3216C_ALS_DATA_HI_SHIFT) | lo; > > + tmp *= ap3216c_gain_array[cfg & AP3216C_ALS_CFG_GAIN_MASK]; > > + > > + *val = tmp; > > + *val2 = AP3216C_ALS_DATA_DENOM; > > + > > + return IIO_VAL_FRACTIONAL; > > + default: > > + return -EINVAL; > > + } > > + case IIO_CHAN_INFO_RAW: > > + switch (chan->type) { > > + case IIO_LIGHT: > > + if (chan->channel2 != IIO_MOD_LIGHT_IR) > > + return -EINVAL; > > + > > + ret = regmap_read(data->regmap, > > + AP3216C_IR_DATA_LO, &lo); > > + if (ret < 0) > > + return ret; > > + > > + ret = regmap_read(data->regmap, > > + AP3216C_IR_DATA_HI, &hi); > > + if (ret < 0) > > + return ret; > > + > > + tmp = lo & AP3216C_IR_DATA_LO_MASK; > > + tmp |= hi << AP3216C_IR_DATA_HI_SHIFT; > > + *val = tmp; > > + > > + return IIO_VAL_INT; > > + > > + case IIO_PROXIMITY: > > + ret = regmap_read(data->regmap, > > + AP3216C_PS_DATA_LO, &lo); > > + if (ret < 0) > > + return ret; > > + > > + ret = regmap_read(data->regmap, > > + AP3216C_PS_DATA_HI, &hi); > > + if (ret < 0) > > + return ret; > > + > > + ret = regmap_read(data->regmap, > > + AP3216C_PS_CFG, &cfg); > > + if (ret < 0) > > + return ret; > > + > > + tmp = lo & AP3216C_PS_DATA_LO_MASK; > > + tmp |= (hi & AP3216C_PS_DATA_HI_MASK) << > > + AP3216C_PS_DATA_HI_SHIFT; > > + *val = tmp * AP3216C_PS_CFG_GAIN(cfg); > > + > > + return IIO_VAL_INT; > > + default: > > + return -EINVAL; > > + } > > + default: > > + return -EINVAL; > > + } > > + return -EINVAL; > > +} > > + > > +static const struct iio_info ap3216c_info = { > > + .read_raw = ap3216c_read_raw, > > + .write_raw = ap3216c_write_raw, > > + .read_event_value = ap3216c_read_event_value, > > + .write_event_value = ap3216c_write_event_value, > > + .read_event_config = ap3216c_read_event_config, > > + .write_event_config = ap3216c_write_event_config, > > +}; > > + > > +static int ap3216c_clear_int(struct ap3216c_data *data) > > +{ > > + return regmap_write(data->regmap, > > + AP3216C_INT_STATUS, AP3216C_INT_STATUS_CLR); > > +} > > + > > +static irqreturn_t ap3216c_event_handler(int irq, void *p) > > +{ > > + struct iio_dev *indio_dev = p; > > + struct ap3216c_data *data = iio_priv(indio_dev); > > + int status; > > + s64 timestamp; > > + int ret; > > + > > + ret = regmap_read(data->regmap, AP3216C_INT_STATUS, &status); > > + if (ret) { > > + /* > > + * Without being able to guarantee the interrupt came from > > + * this device, we must return IRQ_HANDLED instead of > > + * IRQ_NONE. > > + */ > > Do you know why? I'm not saying this is wrong, just curious to know why. > Because if the chip becomes unresponsive, now the driver will consume > all interrupts on the shared interrupt line, right ? > > > + dev_err(&data->client->dev, "error reading IRQ status\n"); > > + return IRQ_HANDLED; > > + } > > + > > + /* The IRQ was not from this device */ > > + if (!status) > > + return IRQ_NONE; > > + > > + timestamp = iio_get_time_ns(indio_dev); > > + if ((status & AP3216C_INT_STATUS_PS_MASK) && data->prox_thresh_en) > > + iio_push_event(indio_dev, > > + IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0, > > + IIO_EV_TYPE_THRESH, > > + IIO_EV_DIR_EITHER), > > + timestamp); > > + > > + if ((status & AP3216C_INT_STATUS_ALS_MASK) && data->als_thresh_en) > > + iio_push_event(indio_dev, > > + IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0, > > + IIO_EV_TYPE_THRESH, > > + IIO_EV_DIR_EITHER), > > + timestamp); > > I'm a complete newbie re. this driver and the iio subsystem in general, but I > suspect that events could be lost here: > > Example flow: > 1. device generates ALS data, writes it to the register, asserts interrupt > 2. this event handler executes, it's a threaded event handler, so may be > interleaved with userspace threads > 3. this event handler calls iio_push_event() and is then paused by the scheduler > 4. a userspace thread monitoring the iio interface reacts to to the event, > and reads the ALS data > 5. the device generates _new_ ALS data, interrupt already asserted > 6. the threaded event handler continues executing, clears the interrupt > > Result: new ALS data is available, but iio did not get an event ? > > If this is indeed an issue, you might be able to address this by locking > the interrupt handler and ALS/PS read with a mutex ? > > But of course if you do that, you might end up with an interrupt / event > for a value you've already read out. That's fine only if iio core is ok with > spurious events. I may be missing something. That datasheet isn't the clearest I've ever seen... I think this device is running in a self clocked mode if we are running with events. So an additional read will not result in an additional event. Also the interrupt is latching. If we get a repeat of the same event it is generally of no interest to userspace. If it's a different event we'll get an additional bit latched. So yes, it's more than possible that userspace won't get the same number of events as samples taken over the limit, but I don't know why we care. We can about missing a threshold being passed entirely, not about knowing how many samples we were above it for. > > > + > > + ret = ap3216c_clear_int(data); > > + if (ret < 0) > > + dev_err(&data->client->dev, "error clearing IRQ\n"); > > + > > + return IRQ_HANDLED; > > +} > > + > > +static int ap3216c_probe(struct i2c_client *client, > > + const struct i2c_device_id *id) > > +{ > > + struct ap3216c_data *data; > > + struct iio_dev *indio_dev; > > + int ret; > > + > > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > > + if (!indio_dev) > > + return -ENOMEM; > > + > > + data = iio_priv(indio_dev); > > + data->client = client; > > + indio_dev->dev.parent = &client->dev; > > + indio_dev->info = &ap3216c_info; > > + indio_dev->name = AP3216C_DRV_NAME; > > + indio_dev->channels = ap3216c_channels; > > + indio_dev->num_channels = ARRAY_SIZE(ap3216c_channels); > > + > > + data->regmap = devm_regmap_init_i2c(client, &ap3216c_regmap_config); > > + if (IS_ERR(data->regmap)) { > > + dev_err(&client->dev, "Failed to allocate register map\n"); > > + return PTR_ERR(data->regmap); > > + } > > + > > + /* Default to thresh events disabled */ > > + data->als_thresh_en = false; > > + data->prox_thresh_en = false; > > + > > + /* > > + * Require that that the interrupt is cleared only when the INT > > + * register is written to, instead of when data is read. This > > + * prevents the interrupt from falsely reporting IRQ_NONE. > > + */ > > + ret = regmap_write(data->regmap, > > + AP3216C_INT_CLR, AP3216C_INT_CLR_MANUAL); > > + if (ret < 0) > > + return ret; > > + > > + /* Before setting up IRQ, clear any stale interrupt */ > > + ret = ap3216c_clear_int(data); > > + if (ret < 0) > > + return ret; > > + > > + if (client->irq) { > > + ret = devm_request_threaded_irq(&client->dev, client->irq, > > + NULL, ap3216c_event_handler, > > + IRQF_TRIGGER_FALLING | > > + IRQF_SHARED | IRQF_ONESHOT, > > + client->name, indio_dev); > > + if (ret) > > + return ret; > > + } > > + > > + /* Enable ALS and PS+IR */ > > + ret = regmap_write(data->regmap, AP3216C_SYS, AP3216C_SYS_MODE_ALS_PS); > > + if (ret < 0) > > + return ret; > > + > > + return devm_iio_device_register(&client->dev, indio_dev); > > +} > > + > > +static const struct of_device_id ap3216c_of_match[] = { > > + { .compatible = "liteon,ap3216c", }, > > + { }, > > +}; > > +MODULE_DEVICE_TABLE(of, ap3216c_of_match); > > + > > +static const struct i2c_device_id ap3216c_id[] = { > > + {"ap3216c", 0}, > > + { } > > +}; > > +MODULE_DEVICE_TABLE(i2c, ap3216c_id); > > + > > +static struct i2c_driver ap3216c_driver = { > > + .driver = { > > + .name = AP3216C_DRV_NAME, > > + }, > > + .probe = ap3216c_probe, > > + .id_table = ap3216c_id, > > +}; > > +module_i2c_driver(ap3216c_driver); > > + > > +MODULE_AUTHOR("Robert Eshleman "); > > +MODULE_DESCRIPTION("APC3216C Ambient Light and Proximity Sensor"); > > +MODULE_LICENSE("GPL v2"); > > -- > > 2.20.1 > >