On Mon, 22 Aug 2022 15:51:05 +0300 Ciprian Regus <ciprian.regus@xxxxxxxxxx> wrote: > The LTC2499 is a 16-channel (eight differential), 24-bit, > ADC with Easy Drive technology and a 2-wire, I2C interface. > > Implement support for the LTC2499 ADC by extending the LTC2497 > driver. A new chip_info struct is added to differentiate between > chip types and resolutions when reading data from the device. > > Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/2499fe.pdf > > Signed-off-by: Ciprian Regus <ciprian.regus@xxxxxxxxxx> Hi Ciprian, Various comments inline. Thanks, Jonathan > --- > drivers/iio/adc/ltc2496.c | 8 +++++++- > drivers/iio/adc/ltc2497-core.c | 2 +- > drivers/iio/adc/ltc2497.c | 34 +++++++++++++++++++++++++++++----- > drivers/iio/adc/ltc2497.h | 13 ++++++++++++- > 4 files changed, 49 insertions(+), 8 deletions(-) > > diff --git a/drivers/iio/adc/ltc2496.c b/drivers/iio/adc/ltc2496.c > index dfb3bb5997e5..98338104c24a 100644 > --- a/drivers/iio/adc/ltc2496.c > +++ b/drivers/iio/adc/ltc2496.c > @@ -14,6 +14,7 @@ > #include <linux/iio/iio.h> > #include <linux/iio/driver.h> > #include <linux/module.h> > +#include <linux/property.h> why? > #include <linux/mod_devicetable.h> > > #include "ltc2497.h" > @@ -74,6 +75,7 @@ static int ltc2496_probe(struct spi_device *spi) > spi_set_drvdata(spi, indio_dev); > st->spi = spi; > st->common_ddata.result_and_measure = ltc2496_result_and_measure; > + st->common_ddata.chip_info = device_get_match_data(dev); > > return ltc2497core_probe(dev, indio_dev); > } > @@ -85,8 +87,12 @@ static void ltc2496_remove(struct spi_device *spi) > ltc2497core_remove(indio_dev); > } > > +static struct chip_info ltc2496_info = { > + .resolution = 16, > +}; > + > static const struct of_device_id ltc2496_of_match[] = { > - { .compatible = "lltc,ltc2496", }, > + { .compatible = "lltc,ltc2496", .data = (void *)<c2496_info }, as below. Take the chip_info structure const and drop the cast. > {}, > }; > MODULE_DEVICE_TABLE(of, ltc2496_of_match); > diff --git a/drivers/iio/adc/ltc2497-core.c b/drivers/iio/adc/ltc2497-core.c > index 2a485c8a1940..b2752399402c 100644 > --- a/drivers/iio/adc/ltc2497-core.c > +++ b/drivers/iio/adc/ltc2497-core.c > @@ -95,7 +95,7 @@ static int ltc2497core_read_raw(struct iio_dev *indio_dev, > return ret; > > *val = ret / 1000; > - *val2 = 17; > + *val2 = ddata->chip_info->resolution + 1; > > return IIO_VAL_FRACTIONAL_LOG2; > > diff --git a/drivers/iio/adc/ltc2497.c b/drivers/iio/adc/ltc2497.c > index f7c786f37ceb..bb5e0d4301e2 100644 > --- a/drivers/iio/adc/ltc2497.c > +++ b/drivers/iio/adc/ltc2497.c > @@ -7,10 +7,14 @@ > * Datasheet: http://cds.linear.com/docs/en/datasheet/2497fd.pdf > */ > > +#include <linux/bitfield.h> > +#include <linux/bitops.h> Not immediately obvious why these need adding as part of this patch. If just general include improvement, separate patch please. > + Why blank line? > #include <linux/i2c.h> > #include <linux/iio/iio.h> > #include <linux/iio/driver.h> > #include <linux/module.h> > +#include <linux/property.h> May make sense, but not obvious why it's in this patch. If it's missing and should be present, please do it in a separate patch. > #include <linux/mod_devicetable.h> > > #include "ltc2497.h" > @@ -19,6 +23,8 @@ struct ltc2497_driverdata { > /* this must be the first member */ > struct ltc2497core_driverdata common_ddata; > struct i2c_client *client; > + u32 recv_size; > + u32 sub_lsb; > /* > * DMA (thus cache coherency maintenance) may require the > * transfer buffers to live in their own cache lines. > @@ -34,13 +40,14 @@ static int ltc2497_result_and_measure(struct ltc2497core_driverdata *ddata, > int ret; > > if (val) { > - ret = i2c_master_recv(st->client, (char *)&st->buf, 3); > + ret = i2c_master_recv(st->client, (char *)&st->buf, st->recv_size); Not helpful yet, but there was a patch series under review form Jason Gerecke that changed the i2c transfer commands to use a u8. Which raises a question. buf is a __be32 which is rather odd given size of 3 in original code. If we have a case where it needs to have separate types for different transfers, use a union. > if (ret < 0) { > dev_err(&st->client->dev, "i2c_master_recv failed\n"); > return ret; > } > > - *val = (be32_to_cpu(st->buf) >> 14) - (1 << 17); Old code here is less than ideal, should be reading into 3 bytes then using the be24 accesors. Please fix whilst here. You will need multiple paths here depending on size. > + *val = (be32_to_cpu(st->buf) >> st->sub_lsb) - > + BIT(ddata->chip_info->resolution + 1); > } > > ret = i2c_smbus_write_byte(st->client, > @@ -54,6 +61,7 @@ static int ltc2497_result_and_measure(struct ltc2497core_driverdata *ddata, > static int ltc2497_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > + u32 resolution; > struct iio_dev *indio_dev; > struct ltc2497_driverdata *st; > struct device *dev = &client->dev; > @@ -70,6 +78,11 @@ static int ltc2497_probe(struct i2c_client *client, > i2c_set_clientdata(client, indio_dev); > st->client = client; > st->common_ddata.result_and_measure = ltc2497_result_and_measure; > + st->common_ddata.chip_info = device_get_match_data(dev); > + > + resolution = st->common_ddata.chip_info->resolution; > + st->sub_lsb = 31 - (resolution + 1); > + st->recv_size = resolution / BITS_PER_BYTE + 1; > > return ltc2497core_probe(dev, indio_dev); > } > @@ -83,15 +96,26 @@ static int ltc2497_remove(struct i2c_client *client) > return 0; > } > > +static struct chip_info ltc2497_info[] = { Should be const - which is why you need the cast below. > + [TYPE_LTC2497] = { > + .resolution = 16, > + }, > + [TYPE_LTC2499] = { > + .resolution = 24, > + } > +}; > + > static const struct i2c_device_id ltc2497_id[] = { > - { "ltc2497", 0 }, > + { "ltc2497", TYPE_LTC2497 }, > + { "ltc2499", TYPE_LTC2499 }, > { } > }; > MODULE_DEVICE_TABLE(i2c, ltc2497_id); > > static const struct of_device_id ltc2497_of_match[] = { > - { .compatible = "lltc,ltc2497", }, > - {}, > + { .compatible = "lltc,ltc2497", .data = (void *)<c2497_info[TYPE_LTC2497] }, > + { .compatible = "lltc,ltc2499", .data = (void *)<c2497_info[TYPE_LTC2499] }, Cast is a bad sign. Reason above. > + {} > }; > MODULE_DEVICE_TABLE(of, ltc2497_of_match); > > diff --git a/drivers/iio/adc/ltc2497.h b/drivers/iio/adc/ltc2497.h > index d0b42dd6b8ad..f4d939cfd48b 100644 > --- a/drivers/iio/adc/ltc2497.h > +++ b/drivers/iio/adc/ltc2497.h > @@ -4,9 +4,20 @@ > #define LTC2497_CONFIG_DEFAULT LTC2497_ENABLE > #define LTC2497_CONVERSION_TIME_MS 150ULL > > +enum chip_type { > + TYPE_LTC2496, > + TYPE_LTC2497, > + TYPE_LTC2499 > +}; > + > +struct chip_info { > + u32 resolution; > +}; > + > struct ltc2497core_driverdata { > struct regulator *ref; > - ktime_t time_prev; > + ktime_t time_prev; I'm staring at this and can't see the difference between the two lines. Closer inspection (i.e. messing with the stuff around it) tells me line you are removing has a tab when should be a space. Whilst trivial please call that out in patch description (or do it as a separate patch). > + const struct chip_info *chip_info; > u8 addr_prev; > int (*result_and_measure)(struct ltc2497core_driverdata *ddata, > u8 address, int *val);
