On Wed, 2020-03-18 at 10:31 +0100, Lars-Peter Clausen wrote: > On 3/18/20 7:50 AM, Ardelean, Alexandru wrote: > > On Tue, 2020-03-17 at 22:17 +0200, Alexandru Lazar wrote: > > > [External] > > > > > > Add driver for the Maxim MAX1241 12-bit, single-channel ADC. The driver > > > includes support for this device's low-power operation mode. > > > > hey, > > > > overall looks good; > > > > i'd run ./scripts/checpatch.pl on the patches a bit; > > you can run it on the patch file, or on the git commit with > > ./scripts/checpatch.pl -g <git-commits> > > > > i usually do ./scripts/checpatch.pl -g HEAD~2.. [or something like that] > > before > > generating patches; > > i sometimes forget to do that; > > > > some more comments inline > > > > > > > Signed-off-by: Alexandru Lazar <alazar@xxxxxxxxxxxxx> > > > --- > > > drivers/iio/adc/Kconfig | 12 +++ > > > drivers/iio/adc/Makefile | 1 + > > > drivers/iio/adc/max1241.c | 215 ++++++++++++++++++++++++++++++++++++++ > > > 3 files changed, 228 insertions(+) > > > create mode 100644 drivers/iio/adc/max1241.c > > > > > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > > > index 5d8540b7b427..3a55beec69c9 100644 > > > --- a/drivers/iio/adc/Kconfig > > > +++ b/drivers/iio/adc/Kconfig > > > @@ -566,6 +566,18 @@ config MAX1118 > > > To compile this driver as a module, choose M here: the module > > > will be > > > called max1118. > > > > > > +config MAX1241 > > > + tristate "Maxim max1241 ADC driver" > > > + depends on SPI > > > + select IIO_BUFFER > > > + select IIO_TRIGGERED_BUFFER > > > + help > > > + Say yes here to build support for Maxim max1241 12-bit, single-channel > > > + ADC. > > > > nitpick: this looks inconsistently indented > > > > > + > > > + To compile this driver as a module, choose M here: the module will be > > > + called max1118. > > > + > > > config MAX1363 > > > tristate "Maxim max1363 ADC driver" > > > depends on I2C > > > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > > > index a1f1fbec0f87..37d6f17559dc 100644 > > > --- a/drivers/iio/adc/Makefile > > > +++ b/drivers/iio/adc/Makefile > > > @@ -54,6 +54,7 @@ obj-$(CONFIG_LTC2497) += ltc2497.o > > > obj-$(CONFIG_MAX1027) += max1027.o > > > obj-$(CONFIG_MAX11100) += max11100.o > > > obj-$(CONFIG_MAX1118) += max1118.o > > > +obj-$(CONFIG_MAX1241) += max1241.o > > > obj-$(CONFIG_MAX1363) += max1363.o > > > obj-$(CONFIG_MAX9611) += max9611.o > > > obj-$(CONFIG_MCP320X) += mcp320x.o > > > diff --git a/drivers/iio/adc/max1241.c b/drivers/iio/adc/max1241.c > > > new file mode 100644 > > > index 000000000000..2bd31f22fb2c > > > --- /dev/null > > > +++ b/drivers/iio/adc/max1241.c > > > @@ -0,0 +1,215 @@ > > > +// SPDX-License-Identifier: GPL-2.0-only > > > +/* > > > + * MAX1241 low-power, 12-bit serial ADC > > > + * > > > + * Copyright (c) 2020 Ioan-Alexandru Lazar <alazar@xxxxxxxxxxxxx> > > > + * > > > + * This file is subject to the terms and conditions of version 2 of > > > + * the GNU General Public License. See the file COPYING in the main > > > + * directory of this archive for more details. > > > > This license text is no longer needed. > > The SPDX-License-Identifier header should handle that. > > > > > + * > > > + * Datasheet: > > > https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf > > > + */ > > > + > > > +#include <linux/regulator/consumer.h> > > > +#include <linux/delay.h> > > > +#include <linux/gpio/consumer.h> > > > +#include <linux/gpio/driver.h> > > > +#include <linux/gpio.h> > > > +#include <linux/iio/iio.h> > > > +#include <linux/module.h> > > > +#include <linux/spi/spi.h> > > > + > > > +#define MAX1241_VAL_MASK 0xFFF > > > +#define MAX1241_SHDN_DELAY_USEC 4 > > > + > > > +enum max1241_id { > > > + max1241, > > > +}; > > > + > > > +struct max1241 { > > > + struct spi_device *spi; > > > + struct mutex lock; > > > + struct regulator *reg; > > > + struct gpio_desc *shdn; > > > + > > > + __be16 data ____cacheline_aligned; > > > > Jonathan may know better than me here, but you could technically avoid > > needing > > to explicitly use the __be16 datatype; and just use u16; > > > > i think the SPI framework should have some handling for that; > > maybe using the 'bits_per_word' field; > > you'd probably still need to do the shifting though; > > i remember some discussion about this on ad7949.c > > though there may be other drivers doing this as well > > I'd keep it as it is. Which bits_per_word values are supported depends > on the SPI master driver. All of them support 8-bit, but many don't > support 16-bit. Fair enough. I'm a bit vague on the details here. > > - Lars
