On Sat, 19 Jan 2019, Jonathan Cameron wrote: some more comments from my side below... > On Wed, 16 Jan 2019 22:56:23 -0800 > Robert Eshleman <bobbyeshleman@xxxxxxxxx> wrote: > > Hi Robert, > > Note I review drivers backwards, so comments may make more sense that > way around. > > > The MAX44009 is a low-power ambient light sensor from Maxim Integrated. > > It differs from the MAX44000 in that it doesn't have proximity sensing and that > > it requires far less current (1 micro-amp vs 5 micro-amps). The register > > mapping and feature set between the two are different enough to require a new > > driver for the MAX44009. > > > > Developed and tested with a BeagleBone Black and UDOO Neo (i.MX6SX) > > > > Supported features: > > > > * Rising and falling illuminance threshold > > events > > Not really on this one. You support using them as a trigger, which > is not how threshold events should be handled in IIO. Please > report them as events. This device doesn't seem to have > a trigger that can be used in general, so you shouldn't provide > one. > > Userspace can use the event to decide to do a read if it wants to > follow the classic move the thresholds so as to detect big > 'changes' in light intensity. > > Various other comments inline. Quite a bit of style cleanup > needed as well, please check the kernel docs for coding style > https://www.kernel.org/doc/Documentation/process/coding-style.rst > > Also take a look at other IIO drivers for the bits that are > noted in there as varying across the kernel. > > Whilst there is quite a bit to work on in here yet, great to see > support for this new part! Looking forward to v2. > > Jonathan > > > > > * Illuminance triggered buffers > > > > * Integration time > > > > https://datasheets.maximintegrated.com/en/ds/MAX44009.pdf > > > > Signed-off-by: Robert Eshleman <bobbyeshleman@xxxxxxxxx> > > > --- > > .../bindings/iio/light/max44009.txt | 25 + > > drivers/iio/light/Kconfig | 13 + > > drivers/iio/light/Makefile | 1 + > > drivers/iio/light/max44009.c | 696 ++++++++++++++++++ > > 4 files changed, 735 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/iio/light/max44009.txt > > create mode 100644 drivers/iio/light/max44009.c > > > > diff --git a/Documentation/devicetree/bindings/iio/light/max44009.txt b/Documentation/devicetree/bindings/iio/light/max44009.txt > > new file mode 100644 > > index 000000000000..220c2808dca1 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/iio/light/max44009.txt > > @@ -0,0 +1,25 @@ > > +* MAX44009 Ambient Light Sensor > > + > > +Required properties: > > + > > +- compatible: should be "maxim,max44009" > > +- reg: the I2C address of the device (default is <0x4a>) > > + > > +Optional properties: > > + > > +- interrupts : interrupt mapping for GPIO IRQ. Should be configured with the space before the colon hurts my eyes > > + IRQ_TYPE_EDGE_FALLING. > > + > > +Refer to interrupt-controller/interrupts.txt for generic interrupt client > > +node bindings. > > + > > +Example: > > + > > +max44009: max44009@4a { > > + compatible = "maxim,max44009"; > > + reg = <0x4a>; > > + > > + interrupt-parent = <&gpio1>; > > + interrupts = <17 IRQ_TYPE_EDGE_FALLING>; > > +}; > > + > > diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig > > index 36f458433480..cda544f1047d 100644 > > --- a/drivers/iio/light/Kconfig > > +++ b/drivers/iio/light/Kconfig > > @@ -299,6 +299,19 @@ config MAX44000 > > To compile this driver as a module, choose M here: > > the module will be called max44000. > > > > +config MAX44009 > > + tristate "MAX44009 Ambient Light Sensor" > > + depends on I2C > > + select IIO_BUFFER > > + select IIO_TRIGGERED_BUFFER > > + select IIO_TRIGGERED_EVENT > > + help > > + Say Y here if you want to build support for Maxim Integrated's > > + MAX44009 ambient light sensor device. > > + > > + To compile this driver as a module, choose M here: > > + the module will be called max44009. > > + > > config OPT3001 > > tristate "Texas Instruments OPT3001 Light Sensor" > > depends on I2C > > diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile > > index 286bf3975372..e40794fbb435 100644 > > --- a/drivers/iio/light/Makefile > > +++ b/drivers/iio/light/Makefile > > @@ -28,6 +28,7 @@ obj-$(CONFIG_SENSORS_LM3533) += lm3533-als.o > > obj-$(CONFIG_LTR501) += ltr501.o > > obj-$(CONFIG_LV0104CS) += lv0104cs.o > > obj-$(CONFIG_MAX44000) += max44000.o > > +obj-$(CONFIG_MAX44009) += max44009.o > > obj-$(CONFIG_OPT3001) += opt3001.o > > obj-$(CONFIG_PA12203001) += pa12203001.o > > obj-$(CONFIG_RPR0521) += rpr0521.o > > diff --git a/drivers/iio/light/max44009.c b/drivers/iio/light/max44009.c > > new file mode 100644 > > index 000000000000..e15aa8eeb2f6 > > --- /dev/null > > +++ b/drivers/iio/light/max44009.c > > @@ -0,0 +1,696 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * max44009.c - Support for MAX44009 Ambient Light Sensor > > + * > > + * Copyright (c) 2019 Robert Eshleman <bobbyeshleman@xxxxxxxxx> > > + * > > + * 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. > If you have SPDX, no need to have a license statement. > > + * > > + * > > + * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX44009.pdf > > + * > > + * TODO: Support continuous mode and processed event value (IIO_EV_INFO_VALUE) > > + * > > + * Default I2C address: 0x4a > > + * > No point in this blank line. > > > + */ > > + > > +#include <linux/bits.h> > > +#include <linux/i2c.h> > > +#include <linux/iio/buffer.h> > > +#include <linux/iio/events.h> > > +#include <linux/iio/iio.h> > > +#include <linux/iio/sysfs.h> > > +#include <linux/iio/trigger.h> > > +#include <linux/iio/trigger_consumer.h> > > +#include <linux/iio/triggered_buffer.h> > > +#include <linux/init.h> > > +#include <linux/interrupt.h> > > +#include <linux/kernel.h> > > +#include <linux/module.h> > > +#include <linux/regmap.h> > > +#include <linux/util_macros.h> > > + > > +#define MAX44009_DRV_NAME "max44009" > > +#define MAX44009_IRQ_NAME "max44009_event" > > Unless used more than once, no point in defines like this. Just put > the string inline. > > > + > > +/* Registers in datasheet order */ > > +#define MAX44009_REG_STATUS 0x0 > > +#define MAX44009_REG_ENABLE 0x1 > > +#define MAX44009_REG_CFG 0x2 > > +#define MAX44009_REG_LUX_HI 0x3 > > +#define MAX44009_REG_LUX_LO 0x4 > > +#define MAX44009_REG_UPPER_THR 0x5 > > +#define MAX44009_REG_LOWER_THR 0x6 > > +#define MAX44009_REG_THR_TIMER 0x7 > > + > > +#define MAX44009_INT_TIME_MASK (BIT(2) | BIT(1) | BIT(0)) > > GENMASK > > > +#define MAX44009_INT_TIME_SHIFT (0) shift 0 needed? > > + > > +#define MAX44009_MANUAL_MODE_MASK BIT(6) > > + > > +/* The maxmimum raw rising threshold for the max44009 */ maximum > > +#define MAX44009_MAXIMUM_THRESHOLD 8355840 > > + > > +#define MAX44009_HI_NIBBLE(reg) (((reg) >> 4) & 0xf) > > +#define MAX44009_LO_NIBBLE(reg) ((reg) & 0xf) > > + > > +#define MAX44009_EXP_MASK 0xf00 > > +#define MAX44009_EXP_RSHIFT 8 > > +#define MAX44009_LUX_EXP(reg) \ > > + (1 << (((reg) & MAX44009_EXP_MASK) >> MAX44009_EXP_RSHIFT)) > > +#define MAX44009_LUX_MANT(reg) ((reg) & 0xff) > > + > > +#define MAX44009_LUX(reg) (MAX44009_LUX_EXP(reg) * MAX44009_LUX_MANT(reg)) > > These are complex enough that a few small functions with documentation > would be better than macros. > > > + > > +#define MAX44009_THRESH_MANT(reg) ((MAX44009_LO_NIBBLE(reg) << 4) + 15) > > +#define MAX44009_THRESHOLD(reg) \ > > + ((1 << MAX44009_HI_NIBBLE(reg)) * MAX44009_THRESH_MANT(reg)) > > + > > > +static const u32 max44009_int_time_ns_array[] = { > > + 800000000, > > + 400000000, > > + 200000000, > > + 100000000, > > + 50000000, /* Manual mode only */ > > + 25000000, /* Manual mode only */ > > + 12500000, /* Manual mode only */ > > + 6250000, /* Manual mode only */ > > +}; > > + > > +static const char max44009_int_time_str[] = > > + "0.8 " > > + "0.4 " > > + "0.2 " > > + "0.1 " > > + "0.05 " > > + "0.025 " > > + "0.0125 " > > + "0.00625"; > > + > > +static const u8 max44009_scale_avail_ulux_array[] = {45}; > > +static const char max44009_scale_avail_str[] = "0.045"; > > If there is only one value, don't provide the avail stuff > and just put the value in directly where used. CHAN_INFO_SCALE is not exposed but should be to express the 0.045 multiplier > > + > > +struct max44009_data { > > + struct i2c_client *client; > > + struct iio_trigger *trigger; > > + struct mutex lock; > > + int64_t timestamp; > > +}; > > + > > +static const struct iio_event_spec max44009_event_spec[] = { > > + { > > + .type = IIO_EV_TYPE_THRESH, > > + .dir = IIO_EV_DIR_RISING, > > + .mask_separate = BIT(IIO_EV_INFO_VALUE) | > > + BIT(IIO_EV_INFO_ENABLE), > > + }, > > + { > > + .type = IIO_EV_TYPE_THRESH, > > + .dir = IIO_EV_DIR_FALLING, > > + .mask_separate = BIT(IIO_EV_INFO_VALUE) | > > + BIT(IIO_EV_INFO_ENABLE), > > + }, > > +}; > > + > > +static const struct iio_chan_spec max44009_channels[] = { > > + { > > + .type = IIO_LIGHT, > > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_INT_TIME), > > + .scan_index = 0, > > + .scan_type = { > > + .sign = 'u', > > + .realbits = 24, > > + .storagebits = 32, > > + }, > > + .event_spec = max44009_event_spec, > > + .num_event_specs = ARRAY_SIZE(max44009_event_spec), > > + }, > > + IIO_CHAN_SOFT_TIMESTAMP(1), > > +}; > > + > > +static int max44009_read_reg(struct max44009_data *data, char reg) > > +{ > > + struct i2c_client *client = data->client; > > + int ret; > > + > > + mutex_lock(&data->lock); > > + ret = i2c_smbus_read_byte_data(client, reg); > > + if (ret < 0) { > > Same as below. > > > + dev_err(&client->dev, > > + "failed to read reg 0x%0x, err: %d\n", reg, ret); > > + goto err; > > + } > > + > > +err: > > + mutex_unlock(&data->lock); > > + return ret; > > +} > > + > > +static int max44009_write_reg(struct max44009_data *data, char reg, char buf) > > +{ > > + struct i2c_client *client = data->client; > > + int ret; > > + > > + mutex_lock(&data->lock); > > What is this mutex protecting? > > > + ret = i2c_smbus_write_byte_data(client, reg, buf); > > + if (ret < 0) { > > returns 0 on success. So do > if (ret) as it'll prove simpler to follow for handling later. > > > + dev_err(&client->dev, > > + "failed to write reg 0x%0x, err: %d\n", > > + reg, ret); > > + goto err; > > + } > > + > > +err: > > + mutex_unlock(&data->lock); > > + return ret; > > +} > > + > > +static int max44009_read_int_time(struct max44009_data *data) > > +{ > > + int ret = max44009_read_reg(data, MAX44009_REG_CFG); > > + > > + if (ret < 0) { > > + return ret; > > + } > > + > > + return max44009_int_time_ns_array[ret & MAX44009_INT_TIME_MASK]; > > +} > > + > > +static int max44009_write_raw(struct iio_dev *indio_dev, > > + struct iio_chan_spec const *chan, int val, > > + int val2, long mask) > > +{ > > + struct max44009_data *data = iio_priv(indio_dev); > > + int ret, int_time; > > + s64 ns; > > + > > + if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT) { > > + ns = val * NSEC_PER_SEC + val2; > > + int_time = find_closest_descending( > > + ns, > > + max44009_int_time_ns_array, > > + ARRAY_SIZE(max44009_int_time_ns_array)); > > + a mutex might make sense here to protect the read/write combo > > + ret = max44009_read_reg(data, MAX44009_REG_CFG); > > + if (ret < 0) > > + return ret; > > + > > + ret &= ~MAX44009_INT_TIME_MASK; > > + ret |= (int_time << MAX44009_INT_TIME_SHIFT); > > + ret |= MAX44009_MANUAL_MODE_MASK; > > + > > + return max44009_write_reg(data, MAX44009_REG_CFG, ret); > > + } > > + return -EINVAL; > > +} > > + > > +static int max44009_write_raw_get_fmt(struct iio_dev *indio_dev, > > + struct iio_chan_spec const *chan, > > + long mask) > > +{ > > + if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT) { > > Make sure to get rid of all the brackets where kernel style doesn't have them. > Basically any single statements if or else blocks (or simiilar). > > > + return IIO_VAL_INT_PLUS_NANO; > > + } else { > > You don't have any others... > > > + return IIO_VAL_INT; > > + } > > +} > > + > > +#define READ_LUX_XFER_LEN (4) MAX44009_ prefix please, no need for () > > + > > +static int max44009_read_lux_raw(struct max44009_data *data) > > +{ > > + int ret; > > + struct i2c_msg xfer[READ_LUX_XFER_LEN]; > > + u8 luxhireg[1] = {MAX44009_REG_LUX_HI}; > > + u8 luxloreg[1] = {MAX44009_REG_LUX_LO}; a simple u8 would work as well, no array > > + u8 lo = 0; > > + u8 hi = 0; > > + u16 reg = 0; > > + > > + xfer[0].addr = data->client->addr; > > + xfer[0].flags = 0; > > + xfer[0].len = 1; sizeof(luxhireg)? > > + xfer[0].buf = luxhireg; > > + > > + xfer[1].addr = data->client->addr; > > + xfer[1].flags = I2C_M_RD; > > + xfer[1].len = 1; sizeof(&hi)? > > + xfer[1].buf = &hi; > > + > > + xfer[2].addr = data->client->addr; > > + xfer[2].flags = 0; > > + xfer[2].len = 1; > > + xfer[2].buf = luxloreg; > > + > > + xfer[3].addr = data->client->addr; > > + xfer[3].flags = I2C_M_RD; > > + xfer[3].len = 1; > > + xfer[3].buf = &lo; > > + > > + /* > > + * Use i2c_transfer instead of smbus read because i2c_transfer > > + * does NOT use a stop bit between address write and data read. > > + * Using a stop bit causes disjoint upper/lower byte reads and > > + * reduces accuracy > > + */ > > + mutex_lock(&data->lock); mutex needed? > > + ret = i2c_transfer(data->client->adapter, xfer, READ_LUX_XFER_LEN); > > + mutex_unlock(&data->lock); > > + if (ret != READ_LUX_XFER_LEN) { > > + return -EIO; > > + } > > + > > + reg = (((u16)hi) << 4) | (lo & 0xf); > > > + > > + return MAX44009_LUX(reg); > > +} > > + > > +static int max44009_read_raw(struct iio_dev *indio_dev, > > + struct iio_chan_spec const *chan, int *val, > > + int *val2, long mask) > > +{ > > + struct max44009_data *data = iio_priv(indio_dev); > > + int ret; > > + > > + switch (mask) { > > + case IIO_CHAN_INFO_RAW: { > > + switch (chan->type) { > > + case IIO_LIGHT: { > > + ret = max44009_read_lux_raw(data); > > + if (ret < 0) { > > + return ret; > > + } > > + *val = ret; > > + *val2 = 0; > > + return IIO_VAL_INT; > > + } > > + default: > > + return -EINVAL; > > + } > > + break; > > + } > > + > > + case IIO_CHAN_INFO_INT_TIME: { > > + ret = max44009_read_int_time(data); > > + if (ret < 0) { > > + return ret; > > + } > > + > > + *val2 = ret; > > + *val = 0; > > + return IIO_VAL_INT_PLUS_NANO; > > + } > > + > > + default: > > + return -EINVAL; > > + } > > +} > > + > > +static IIO_CONST_ATTR(illuminance_scale_available, max44009_scale_avail_str); channels do not have CHAN_INFO_SCALE, so why expose scale_available? > > +static IIO_CONST_ATTR(illuminance_integration_time_available, > > + max44009_int_time_str); > > + > > +static struct attribute *max44009_attributes[] = { > > + &iio_const_attr_illuminance_integration_time_available.dev_attr.attr, > > + &iio_const_attr_illuminance_scale_available.dev_attr.attr, NULL > > +}; > > + > > +static const struct attribute_group max44009_attribute_group = { > > + .attrs = max44009_attributes, > > +}; > > + > > +static int max44009_thresh_byte_from_int(int thresh) > > +{ > > + int mantissa, exp; > > + > > + if (thresh < 0 || thresh > MAX44009_MAXIMUM_THRESHOLD) { > > + return -EINVAL; > > + } > > + > > + for (mantissa = thresh, exp = 0; mantissa > 0xff; exp++) { > > + mantissa >>= 1; > > + } > > + > > + mantissa >>= 4; > > + mantissa &= 0xf; > > + exp <<= 4; > > + > > + return exp | mantissa; > > +} > > + > > +static int max44009_get_thr_reg(enum iio_event_direction dir) > > +{ > > + switch (dir) { > > + case IIO_EV_DIR_RISING: > > + return MAX44009_REG_UPPER_THR; > > + case IIO_EV_DIR_FALLING: > > + return MAX44009_REG_LOWER_THR; > > + default: > > + return -EINVAL; > > + } > > +} > > + > > +static int max44009_write_thresh(struct iio_dev *indio_dev, > > + enum iio_event_direction dir, int val) > > +{ > > + struct max44009_data *data = iio_priv(indio_dev); > > + int thresh; > > + int reg; > > + > > + reg = max44009_get_thr_reg(dir); > > + if (reg < 0) { > > + return reg; > > + } > > + > > + thresh = max44009_thresh_byte_from_int(val); > > + if (thresh < 0) { > > + return thresh; > > + } > > + > > + return max44009_write_reg(data, reg, thresh); > > +} > > + > > +static int max44009_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) > > +{ > > + if (info != IIO_EV_INFO_VALUE || chan->type != IIO_LIGHT || val2 != 0) { > > + return -EINVAL; > > + } > > + > > + return max44009_write_thresh(indio_dev, dir, val); > > +} > > + > > +static int max44009_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) > > +{ > > + int thresh, reg; > > + struct max44009_data *data = iio_priv(indio_dev); > > + > > + if (chan->type != IIO_LIGHT || type != IIO_EV_TYPE_THRESH) { > > + return -EINVAL; > > + } > > + > > + reg = max44009_get_thr_reg(dir); > > + if (reg < 0) { > > + return reg; > > + } > > + > > + thresh = max44009_read_reg(data, reg); > > + if (thresh < 0) { > > + return thresh; > > + } > > + > > + *val = MAX44009_THRESHOLD(thresh); > > + > > + return IIO_VAL_INT; > > +} > > + > > +static int max44009_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 max44009_data *data = iio_priv(indio_dev); > > + int ret; > > + > > + if (chan->type != IIO_LIGHT || type != IIO_EV_TYPE_THRESH) { > > + return -EINVAL; > > + } > > + > > + ret = max44009_write_reg(data, MAX44009_REG_ENABLE, state); > > + if (ret < 0) { > > + return ret; > > + } > > + > > + /* > > + * Set device to trigger interrupt immediately upon exceeding > > + * the threshold limit > > + */ > > + ret = max44009_write_reg(data, MAX44009_REG_THR_TIMER, 0); > > + if (ret < 0) { > > + return ret; > > + } > > + > > + return 0; > > +} > > + > > +static int max44009_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 max44009_data *data = iio_priv(indio_dev); > > + int ret; > > + > > + if (chan->type != IIO_LIGHT || type != IIO_EV_TYPE_THRESH) { > > + return -EINVAL; > > + } > > + > > + ret = max44009_read_reg(data, MAX44009_REG_ENABLE); > > + if (ret < 0) { > > + return ret; > > + } > > + > > + return ret; > > +} > We have lots of event config, but they are actually controlling the > trigger. The device doesn't generate any iio events at all that I can see. > > > + > > +static const struct iio_info max44009_info = { > > + .read_raw = max44009_read_raw, > > + .write_raw = max44009_write_raw, > > + .write_raw_get_fmt = max44009_write_raw_get_fmt, > > + .read_event_value = max44009_read_event_value, > > + .read_event_config = max44009_read_event_config, > > + .write_event_value = max44009_write_event_value, > > + .write_event_config = max44009_write_event_config, > > + .attrs = &max44009_attribute_group, > > +}; > > + > > +static int max44009_set_trigger_state(struct iio_trigger *trigger, > > + bool enable) > > +{ > > + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trigger); > > + struct max44009_data *data = iio_priv(indio_dev); > > + int ret; > > + > > + ret = max44009_write_reg(data, MAX44009_REG_ENABLE, enable); > > + if (ret < 0) { > > + return ret; > > + } > > + > > + ret = max44009_write_reg(data, MAX44009_REG_THR_TIMER, 0); > > + if (ret < 0) { > As suggested above, write_reg should clearly only return 0 or negative. > you can just do > return max440.. > > > + return ret; > > + } > > + > > + return ret; > > +} > > + > > +static const struct iio_trigger_ops max44009_trigger_ops = { > > + .set_trigger_state = max44009_set_trigger_state, > > +}; > > + > > +static irqreturn_t max44009_trigger_handler(int irq, void *p) > > +{ > > + struct iio_dev *indio_dev = p; > > + struct max44009_data *data = iio_priv(indio_dev); > > + int lux, upper, lower; > > + int ret; > > + enum iio_event_direction direction; > > + > > + /* 32-bit for lux and 64-bit for timestamp */ > > + u32 buf[3] = {0}; > > Except the timestamp needs to be 64 bit aligned so this isn't big enough. > All elements in IIO buffers are 'naturally' aligned. so 32 bit is > aligned to 32 bits, 64 to 64 bits. > > > + > > + ret = max44009_read_reg(data, MAX44009_REG_STATUS); > > + if (ret <= 0) { > > + goto err; > > + } > > + > > + ret = max44009_read_reg(data, MAX44009_REG_ENABLE); > > + if (ret <= 0) { > > + goto err; > > + } > > If these reads are necessary, then add comments on why. > > > + > > + /* Clear interrupt by disabling interrupt (see datasheet) */ > > + ret = max44009_write_reg(data, MAX44009_REG_ENABLE, 0); > > + if (ret < 0) { > > + goto err; > > + } > > + > > + lux = max44009_read_lux_raw(data); > > + if (lux < 0) { > > + goto err; > > + } > > + > > + upper = max44009_read_reg(data, MAX44009_REG_UPPER_THR); > > + if (upper < 0) { > > + goto err; > > + } > > + upper = MAX44009_THRESHOLD(upper); > > + > > + lower = max44009_read_reg(data, MAX44009_REG_LOWER_THR); > > + if (lower < 0) { > > + goto err; > > + } > > + lower = MAX44009_THRESHOLD(lower); > > + > > + /* If lux is NOT out-of-bounds then the interrupt was not triggered > > + * by this device > Multiline comment syntax in IIO (and most of the kernel) is > /* > * If... > */ > > Do we support shared interrupt lines? Doesn't look like it, which means > it 'probably was' generate by this device, but we don't know why because the value > has changed. > > Returning IRQ_NONE is a bad idea unless we are pretty sure it is a spurious > interrupt, or we have a shared interrupt line. It will ultimately result > in your interrupt being disable by the kernel and all activity breaking. > > There is also a perfectly good register to tell use if we generated the interrupt. > Read that one and use that, not this racey approach. > > > + */ > > + if (lux < upper && lux > lower) { > > + goto err; > > + } > > + > > + /* Get event for correct thresh direction */ > > + if (lux >= upper) { > > + direction = IIO_EV_DIR_RISING; > > + } else if (lux <= lower) { > > + direction = IIO_EV_DIR_FALLING; > > + } else { > > + goto err; > > + } > > + > > + buf[0] = lux; > > + iio_push_to_buffers_with_timestamp(indio_dev, &buf, data->timestamp); > > + iio_trigger_notify_done(data->trigger); > > + > > + iio_push_event(indio_dev, > > + IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0, > > + IIO_EV_TYPE_THRESH, direction), > > + data->timestamp); > > + > > + ret = max44009_write_reg(data, MAX44009_REG_ENABLE, 1); > > + if (ret < 0) { > > + goto err; > > + } > > + > > + return IRQ_HANDLED; > > + > > +err: > > + /* Re-enable interrupt */ > > + max44009_write_reg(data, MAX44009_REG_ENABLE, 1); > > + return IRQ_NONE; > > +} > > + > > +static irqreturn_t max44009_irq_handler(int irq, void *p) > > +{ > > + struct iio_dev *indio_dev = p; > > + struct max44009_data *data = iio_priv(indio_dev); > > + > > + data->timestamp = iio_get_time_ns(indio_dev); > > We have a standard core function to do this.. > iio_pollfunc_store_time. > > There 'might' be a reason to do it differently depending > on whether you really need it to be that good if you > can't identify whether it is your interrupt until the > interrupt thread. > > > > + return IRQ_WAKE_THREAD; > > +} > > + > > +static int max44009_probe(struct i2c_client *client, > > + const struct i2c_device_id *id) > > +{ > > + struct max44009_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); > > + i2c_set_clientdata(client, indio_dev); > > + data->client = client; > > + indio_dev->dev.parent = &client->dev; > > + indio_dev->info = &max44009_info; > > + indio_dev->modes = INDIO_DIRECT_MODE; > > + indio_dev->name = MAX44009_DRV_NAME; > > + indio_dev->channels = max44009_channels; > > + indio_dev->num_channels = ARRAY_SIZE(max44009_channels); > > + mutex_init(&data->lock); > > + > > + /* Clear stale interrupt bit */ > > + ret = max44009_read_reg(data, MAX44009_REG_STATUS); > > + if (ret < 0) { > > + goto err; > > + } > > + > > + if (client->irq > 0) { > > + ret = devm_request_threaded_irq(&client->dev, client->irq, > > + max44009_irq_handler, > > This is wrong. The interrupt handler should call the iio_trigger_poll functions > to cause the trigger handlers for all attached devices to be called. > > If for some reason the trigger is only suitable for use by this device > then things get more blurred, but if not, the interrupt handler itself > should establish that the interrupt is the data ready signal and call > iio_trigger_poll. If it is in a thread, call iio_trigger_poll_chained. > > The interrupt should be cleared (if it hasn't naturally happened for > some other reason, in the trigger try_reenable callback. > > > > + max44009_trigger_handler, > > + IRQF_TRIGGER_FALLING | > > + IRQF_ONESHOT, > > + MAX44009_IRQ_NAME, indio_dev); > > + if (ret < 0) { > > + goto err; > > + } > > + > > + ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, > > + max44009_irq_handler, > > + max44009_trigger_handler, > > + NULL); > > + if (ret < 0) { > > It's going to change anyway (see below) but note kernel style is no > brackets when only one item in an block like this. > > > + goto err; > > + } > > + > > + data->trigger = devm_iio_trigger_alloc(indio_dev->dev.parent, > > + "%s-dev%d", > > + indio_dev->name, > > + indio_dev->id); > > + if (!data->trigger) { > > + ret = -ENOMEM; > > + goto err; > > + } > > + data->trigger->dev.parent = indio_dev->dev.parent; > > + data->trigger->ops = &max44009_trigger_ops; > > + iio_trigger_set_drvdata(data->trigger, indio_dev); > > + > > + ret = devm_iio_trigger_register(&client->dev, data->trigger); > > + if (ret < 0) { > > + goto err; > > + } > > + } > > + > > + ret = devm_iio_device_register(&client->dev, indio_dev); > > + if (ret < 0) { > > + goto err; > > Without the mutex destroy these all just become return ret; > > > + } > > + > > + return 0; > > +err: > > + mutex_destroy(&data->lock); > > mutex destroy is only really useful for lock debugging. Given we don't > leave anything behind here anyway, it just makes the flow more complex > for no gain. We very rarely bother with it as a result. > > > + return ret; > > +} > > + > > +static const struct i2c_device_id max44009_id[] = { > > + { "max44009", 0 }, > > + { } > > +}; > > +MODULE_DEVICE_TABLE(i2c, max44009_id); > > + > > +static struct i2c_driver max44009_driver = { > > + .driver = { > > + .name = MAX44009_DRV_NAME, > > + }, > > + .probe = max44009_probe, > > + .id_table = max44009_id, > > +}; > > +module_i2c_driver(max44009_driver); > > + > > +static const struct of_device_id max44009_of_match[] = { > > + { .compatible = "maxim,max44009" }, > > + { } > > +}; > > +MODULE_DEVICE_TABLE(of, max44009_of_match); > > + > > +MODULE_AUTHOR("Robert Eshleman <bobbyeshleman@xxxxxxxxx>"); > > +MODULE_LICENSE("GPL v2"); > > +MODULE_VERSION("1.0.0"); > Please drop. MODULE_VERSION provides very little useful info > and tends to lead to people assuming it does. > > Userspace has no obligation to ever look at it and we can't > break userspace that doesn't so it doesn't provide any value. > > > +MODULE_DESCRIPTION("MAX44009 ambient light sensor driver"); > -- Peter Meerwald-Stadler Mobile: +43 664 24 44 418
