On Thu, 12 Jan 2023 19:00:30 +0000 Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > On Tue, 10 Jan 2023 11:01:23 -0500 > Hugo Villeneuve <hugo@xxxxxxxxxxx> wrote: > > > From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx> > > > > The Texas Instruments ADS7924 is a 4 channels, 12-bit analog to > > digital converter (ADC) with an I2C interface. > > > > Datasheet: https://www.ti.com/lit/gpn/ads7924 > > > > Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx> > > Hi Hugo, > > A few minor additional comments from me as you are doing a v3 > (I might just have tidied them up whilst applying otherwise to save > us all time!) No problem, I will add them to my v3. > Thanks, > > Jonathan > > > diff --git a/drivers/iio/adc/ti-ads7924.c b/drivers/iio/adc/ti-ads7924.c > > new file mode 100644 > > index 000000000000..8384f3451236 > > --- /dev/null > > +++ b/drivers/iio/adc/ti-ads7924.c > > @@ -0,0 +1,492 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * IIO driver for Texas Instruments ADS7924 ADC, 12-bit, 4-Channels, I2C > > + * > > + * iio/adc/ti-ads7924.c > > Not a huge amount of point in having a file name in the file. I don't mind > if you really want it though. Removed. > > > + * Author: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx> > > + * Copyright 2022 DimOnOff > > + * > > + * based on iio/adc/ti-ads1015.c > > + * Copyright (c) 2016, Intel Corporation. > > + * > > + * Datasheet: https://www.ti.com/lit/gpn/ads7924 > > + */ > > > + > > +#define ADS7924_TOTAL_CONVTIME_US (ADS7924_PWRUPTIME_US + ADS7924_ACQTIME_US + \ > > + ADS7924_CONVTIME_US) > > + > > +#define ADS7924_SLEEP_DELAY_MS 2000 > > Unused, so drop for now. Removed. > > +static bool ads7924_is_writeable_reg(struct device *dev, unsigned int reg) > > +{ > > + switch (reg) { > > + case ADS7924_MODECNTRL_REG: > > + case ADS7924_INTCNTRL_REG: > > + case ADS7924_ULR0_REG: > > + case ADS7924_LLR0_REG: > > + case ADS7924_ULR1_REG: > > + case ADS7924_LLR1_REG: > > + case ADS7924_ULR2_REG: > > + case ADS7924_LLR2_REG: > > + case ADS7924_ULR3_REG: > > + case ADS7924_LLR3_REG: > > + case ADS7924_INTCONFIG_REG: > > + case ADS7924_SLPCONFIG_REG: > > + case ADS7924_ACQCONFIG_REG: > > + case ADS7924_PWRCONFIG_REG: > > + case ADS7924_RESET_REG: > > + return true; > > + default: > > + return false; > > + } > > +} > > + > > +static const struct regmap_config ads7924_regmap_config = { > > + .reg_bits = 8, > > + .val_bits = 8, > > + .max_register = ADS7924_RESET_REG, > > + .writeable_reg = ads7924_is_writeable_reg, > > +}; > > + > > +static const struct iio_chan_spec ads7924_channels[] = { > > + ADS7924_V_CHAN(0, ADS7924_DATA0_U_REG), > > + ADS7924_V_CHAN(1, ADS7924_DATA1_U_REG), > > + ADS7924_V_CHAN(2, ADS7924_DATA2_U_REG), > > + ADS7924_V_CHAN(3, ADS7924_DATA3_U_REG), > > +}; > > + > > +static > > +int ads7924_get_adc_result(struct ads7924_data *data, > > Drop the unusual line break as not needed (probably refactoring left over!) > static int ... Done. > > + struct iio_chan_spec const *chan, int *val) > > +{ > > + int ret; > > + __be16 be_val; > > + > > + if (chan->channel < 0 || chan->channel >= ADS7924_CHANNELS) > > + return -EINVAL; > > + > > + if (data->conv_invalid) { > > + int conv_time; > > + > > + conv_time = ADS7924_TOTAL_CONVTIME_US; > > + /* Allow 10% for internal clock inaccuracy. */ > > + conv_time += conv_time / 10; > > + usleep_range(conv_time, conv_time + 1); > > + data->conv_invalid = false; > > + } > > + > > + ret = regmap_raw_read(data->regmap, ADS7924_AUTO_INCREMENT_BIT | > > + chan->address, &be_val, sizeof(be_val)); > > + if (ret) > > + return ret; > > + > > + *val = be16_to_cpu(be_val); > > + *val = *val >> ADS7924_DATA_SHIFT; > *val = be16_to_cpu(be_val) >> ADS7924_DATA_SHIFT; > > return 0; Yes, simpler and clearer. Done > > > + > > + return ret; > > +} > > + > > +static int ads7924_read_raw(struct iio_dev *indio_dev, > > + struct iio_chan_spec const *chan, int *val, > > + int *val2, long mask) > > +{ > > + int ret, vref_uv; > > + struct ads7924_data *data = iio_priv(indio_dev); > > + > > + switch (mask) { > > + case IIO_CHAN_INFO_RAW: { > > + mutex_lock(&data->lock); > > + ret = ads7924_get_adc_result(data, chan, val); > > + mutex_unlock(&data->lock); > > + if (ret < 0) > > + dev_dbg(data->dev, "%s error1\n", __func__); > > + else > > + ret = IIO_VAL_INT; > if (ret < 0) { > ... > return ret; > } > > return IIO_VAL_INT; > Done. I also have removed the not-very-informative "error1" message... > > + break; > > + } > > + case IIO_CHAN_INFO_SCALE: > > + vref_uv = regulator_get_voltage(data->vref_reg); > > + if (vref_uv < 0) { > > + /* dummy regulator "get_voltage" returns -EINVAL */ > > + ret = -EINVAL; > return -EINVAL; > > + } else { > > + *val = vref_uv / 1000; /* Convert reg voltage to mV */ > > + *val2 = ADS7924_BITS; > > + ret = IIO_VAL_FRACTIONAL_LOG2; > return IIO_VAL_FR... > > > + } > > + break; > > + default: > > + ret = -EINVAL; > return -EINVAL; > > + break; > > + } > > + > > + return ret; > > +} Done. With these changes, I propose to also remove last "return ret" (like in rcar-gyroadc.c). Then, maybe also remove break statements? > > + > > +static const struct iio_info ads7924_info = { > > + .read_raw = ads7924_read_raw, > The tabbed indent doesn't add anything so > .read_raw = ads... > > Aligning things is often a bad idea anyway as it just adds noise when inevitably > the alignment needs increasing... Definitely not worth doing for one item. Ok, done. > > +}; > > + > > +static int ads7924_get_channels_config(struct i2c_client *client, > > + struct iio_dev *indio_dev) > > +{ > > + struct ads7924_data *priv = iio_priv(indio_dev); > > + struct device *dev = priv->dev; > > + struct fwnode_handle *node; > > + int num_channels = 0; > > + > > + device_for_each_child_node(dev, node) { > > + u32 pval; > > + unsigned int channel; > > + > > + if (fwnode_property_read_u32(node, "reg", &pval)) { > > + dev_err(dev, "invalid reg on %pfw\n", node); > > + continue; > > + } > > + > > + channel = pval; > > + if (channel >= ADS7924_CHANNELS) { > > + dev_err(dev, "invalid channel index %d on %pfw\n", > > + channel, node); > > + continue; > > + } > > + > > + num_channels++; > > + } > > + > > + if (num_channels > 0) { > > + dev_dbg(dev, "found %d ADC channels\n", num_channels); > > + return 0; > > + } else { > > As per other review. Give us what we expect which is error paths > as out of line. Already done as suggested by Christophe: if (num_channels <= 0) return -EINVAL; dev_dbg(dev, "found %d ADC channels\n", num_channels); return 0; Although I do not fully understand what you mean by "...error paths as out of line"? Do you mean to drop the debug message? > > > + return -EINVAL; > > + } > > +} > > > +static int ads7924_reset(struct iio_dev *indio_dev) > > +{ > > + struct ads7924_data *data = iio_priv(indio_dev); > > + > > + if (data->reset_gpio) { > > + gpiod_set_value(data->reset_gpio, 1); /* Assert. */ > > + /* Educated guess: assert time not specified in datasheet... */ > > + mdelay(100); > > + gpiod_set_value(data->reset_gpio, 0); /* Deassert. */ > > No real point in shared exit path. Early returns mean less code to look at > when following particular flows which is always nice. Agreed, done. > return 0; > > > + } else { > > if returning above, no need to have the else { Done > > > + int ret; > > + > > + /* > > + * A write of 10101010 to this register will generate a > > + * software reset of the ADS7924. > > + */ > > + ret = regmap_write(data->regmap, ADS7924_RESET_REG, 0b10101010); > > + if (ret) > > + return ret; > return regmap_write(....) > > > + } > > + > > + return 0; > and drop this. Done. also remove now unused variable "ret". > > +}; > > > +static int ads7924_probe(struct i2c_client *client) > > +{ > > ... > > > + ret = devm_add_action_or_reset(dev, ads7924_set_idle_mode, data); > > The _or_reset() part of this is there so that if this function fails > it will call the callback before returning an error code. As a result > you will turn the device, before you've ever turned it on. > > Register the callback after turning it on, so ... Makes sense, done. > > + if (ret) > > + return dev_err_probe(dev, ret, > > + "failed to add idle mode action\n"); > > + > > + ret = ads7924_set_conv_mode(data, ADS7924_MODECNTRL_AUTO_SCAN); > > + if (ret) > > + return dev_err_probe(dev, ret, > > + "failed to set conversion mode\n"); > > ... here. Thank you a lot for all your comments and meaningfull explanations! -- Hugo Villeneuve <hugo@xxxxxxxxxxx>
