On Fri, 18 Feb 2022 09:50:37 +0530 Jagath Jog J <jagathjog1996@xxxxxxxxx> wrote: > The DS3502 is a 7-bit, nonvolatile digital potentiometer featuring > an output voltage range of up to 15.5V. > DS3502 support is implemented into existing DS1803 driver. > Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3502.pdf > > Signed-off-by: Jagath Jog J <jagathjog1996@xxxxxxxxx> Hi Jagath, One suggestion from my review of v2. Instead of putting the enum for type in the per chip type cfg structure, use a function pointer and break out the device specific bits of the read_raw() into separate functions accessed via that function pointer. Thanks, Jonathan > --- > drivers/iio/potentiometer/Kconfig | 6 ++-- > drivers/iio/potentiometer/ds1803.c | 46 ++++++++++++++++++++++++------ > 2 files changed, 41 insertions(+), 11 deletions(-) > > diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig > index 832df8da2bc6..79c524640196 100644 > --- a/drivers/iio/potentiometer/Kconfig > +++ b/drivers/iio/potentiometer/Kconfig > @@ -27,11 +27,11 @@ config AD5272 > module will be called ad5272. > > config DS1803 > - tristate "Maxim Integrated DS1803 Digital Potentiometer driver" > + tristate "Maxim Integrated DS1803 and similar Digital Potentiometer driver" > depends on I2C > help > - Say yes here to build support for the Maxim Integrated DS1803 > - digital potentiometer chip. > + Say yes here to build support for the Maxim Integrated Devices DS1803 and > + DS3502 digital potentiometer chip. > > To compile this driver as a module, choose M here: the > module will be called ds1803. > diff --git a/drivers/iio/potentiometer/ds1803.c b/drivers/iio/potentiometer/ds1803.c > index ca28ad147402..ca903e9c2816 100644 > --- a/drivers/iio/potentiometer/ds1803.c > +++ b/drivers/iio/potentiometer/ds1803.c > @@ -1,12 +1,15 @@ > // SPDX-License-Identifier: GPL-2.0-only > /* > - * Maxim Integrated DS1803 digital potentiometer driver > + * Maxim Integrated DS1803 and similar digital potentiometer driver > * Copyright (c) 2016 Slawomir Stepien > + * Copyright (c) 2022 Jagath Jog J > * > * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS1803.pdf > + * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3502.pdf > * > * DEVID #Wipers #Positions Resistor Opts (kOhm) i2c address > * ds1803 2 256 10, 50, 100 0101xxx > + * ds3502 1 128 10 01010xx > */ > > #include <linux/err.h> > @@ -18,11 +21,13 @@ > > #define DS1803_WIPER_0 0xA9 > #define DS1803_WIPER_1 0xAA > +#define DS3502_WR_IVR 0x00 > > enum ds1803_type { > DS1803_010, > DS1803_050, > DS1803_100, > + DS3502, > }; > > struct ds1803_cfg { > @@ -36,6 +41,7 @@ struct ds1803_cfg { > struct ds1803_data { > struct i2c_client *client; > const struct ds1803_cfg *cfg; > + enum ds1803_type chip_type; Hmm. I'm not that keen on this backwards reference (effectively). Consider using a read() function pointer in here instead. > }; > > #define DS1803_CHANNEL(ch, addr) { \ > @@ -54,6 +60,10 @@ static const struct iio_chan_spec ds1803_channels[] = { > DS1803_CHANNEL(1, DS1803_WIPER_1), > }; > > +static const struct iio_chan_spec ds3502_channels[] = { > + DS1803_CHANNEL(0, DS3502_WR_IVR), > +}; > + > static const struct ds1803_cfg ds1803_cfg[] = { > [DS1803_010] = { .wipers = 2, .avail = { 0, 1, 255 }, .kohms = 10, > .channels = ds1803_channels, > @@ -64,6 +74,9 @@ static const struct ds1803_cfg ds1803_cfg[] = { > [DS1803_100] = { .wipers = 2, .avail = { 0, 1, 255 }, .kohms = 100, > .channels = ds1803_channels, > .num_channels = ARRAY_SIZE(ds1803_channels) }, > + [DS3502] = { .wipers = 1, .avail = { 0, 1, 127 }, .kohms = 10, > + .channels = ds3502_channels, > + .num_channels = ARRAY_SIZE(ds3502_channels) }, > }; > > static int ds1803_read_raw(struct iio_dev *indio_dev, > @@ -77,13 +90,26 @@ static int ds1803_read_raw(struct iio_dev *indio_dev, > > switch (mask) { > case IIO_CHAN_INFO_RAW: > - ret = i2c_master_recv(data->client, result, > - indio_dev->num_channels); > - if (ret < 0) > - return ret; > - > - *val = result[pot]; > - return IIO_VAL_INT; > + switch (data->chip_type) { > + case DS1803_010: > + case DS1803_050: > + case DS1803_100: This block can become ret = data->read(indio_dev, chan, val); or something along those lines and you can remove the switch statement as it's a simple lookup. > + ret = i2c_master_recv(data->client, result, > + indio_dev->num_channels); > + if (ret < 0) > + return ret; > + *val = result[pot]; > + return IIO_VAL_INT; > + case DS3502: > + ret = i2c_smbus_read_byte_data(data->client, > + chan->address); > + if (ret < 0) > + return ret; > + *val = ret; > + return IIO_VAL_INT; > + default: > + return -EINVAL; > + } > > case IIO_CHAN_INFO_SCALE: > *val = 1000 * data->cfg->kohms; > @@ -156,6 +182,7 @@ static int ds1803_probe(struct i2c_client *client, const struct i2c_device_id *i > if (!data->cfg) > data->cfg = &ds1803_cfg[id->driver_data]; > > + data->chip_type = id->driver_data; > indio_dev->info = &ds1803_info; > indio_dev->channels = data->cfg->channels; > indio_dev->num_channels = data->cfg->num_channels; > @@ -168,6 +195,7 @@ static const struct of_device_id ds1803_dt_ids[] = { > { .compatible = "maxim,ds1803-010", .data = &ds1803_cfg[DS1803_010] }, > { .compatible = "maxim,ds1803-050", .data = &ds1803_cfg[DS1803_050] }, > { .compatible = "maxim,ds1803-100", .data = &ds1803_cfg[DS1803_100] }, > + { .compatible = "maxim,ds3502", .data = &ds1803_cfg[DS3502] }, > {} > }; > MODULE_DEVICE_TABLE(of, ds1803_dt_ids); > @@ -176,6 +204,7 @@ static const struct i2c_device_id ds1803_id[] = { > { "ds1803-010", DS1803_010 }, > { "ds1803-050", DS1803_050 }, > { "ds1803-100", DS1803_100 }, > + { "ds3502", DS3502 }, > {} > }; > MODULE_DEVICE_TABLE(i2c, ds1803_id); > @@ -192,5 +221,6 @@ static struct i2c_driver ds1803_driver = { > module_i2c_driver(ds1803_driver); > > MODULE_AUTHOR("Slawomir Stepien <sst@xxxxxxxxx>"); > +MODULE_AUTHOR("Jagath Jog J <jagathjog1996@xxxxxxxxx>"); > MODULE_DESCRIPTION("DS1803 digital potentiometer"); > MODULE_LICENSE("GPL v2");
