On Mon, 9 Dec 2019 21:32:48 +0100 Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> wrote: > This chip is similar to the LTC2497 ADC, it just uses SPI instead of I2C > and so has a slightly different protocol. Only the actual hardware > access is different. The spi protocol is different enough to not be able > to map the differences via a regmap. > > Also generalize the entry in MAINTAINER to cover the newly introduced > file. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> Hmm. I'm a little surprised this doesn't run into the issues we used to have with single files being linked twice and the interactions between built in drivers and modules. However I've just tried every combination on x86_64 and it seems to be fine. Perhaps something got made more flexible in the build system recently that I missed, or there is a subtle detail that is different about this particular case. With that in mind, applied to the togreg branch of iio.git and pushed out as testing to let the autobuilders play with it. Thanks, Jonathan > --- > MAINTAINERS | 2 +- > drivers/iio/adc/Kconfig | 10 ++++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/ltc2496.c | 108 ++++++++++++++++++++++++++++++++++++++ > 4 files changed, 120 insertions(+), 1 deletion(-) > create mode 100644 drivers/iio/adc/ltc2496.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index eb19fad370d7..8b1211038617 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -1029,7 +1029,7 @@ S: Supported > F: Documentation/ABI/testing/sysfs-bus-iio-frequency-ad9523 > F: Documentation/ABI/testing/sysfs-bus-iio-frequency-adf4350 > F: drivers/iio/*/ad* > -F: drivers/iio/adc/ltc2497* > +F: drivers/iio/adc/ltc249* > X: drivers/iio/*/adjd* > F: drivers/staging/iio/*/ad* > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index f0af3a42f53c..deb86f6039b3 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -492,6 +492,16 @@ config LTC2485 > To compile this driver as a module, choose M here: the module will be > called ltc2485. > > +config LTC2496 > + tristate "Linear Technology LTC2496 ADC driver" > + depends on SPI > + help > + Say yes here to build support for Linear Technology LTC2496 > + 16-Bit 8-/16-Channel Delta Sigma ADC. > + > + To compile this driver as a module, choose M here: the module will be > + called ltc2496. > + > config LTC2497 > tristate "Linear Technology LTC2497 ADC driver" > depends on I2C > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index ee0c8dcfb501..c3dc2a12766a 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -47,6 +47,7 @@ obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o > obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o > obj-$(CONFIG_LTC2471) += ltc2471.o > obj-$(CONFIG_LTC2485) += ltc2485.o > +obj-$(CONFIG_LTC2496) += ltc2496.o ltc2497-core.o > obj-$(CONFIG_LTC2497) += ltc2497.o ltc2497-core.o > obj-$(CONFIG_MAX1027) += max1027.o > obj-$(CONFIG_MAX11100) += max11100.o > diff --git a/drivers/iio/adc/ltc2496.c b/drivers/iio/adc/ltc2496.c > new file mode 100644 > index 000000000000..88a30156a849 > --- /dev/null > +++ b/drivers/iio/adc/ltc2496.c > @@ -0,0 +1,108 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * ltc2496.c - Driver for Analog Devices/Linear Technology LTC2496 ADC > + * > + * Based on ltc2497.c which has > + * Copyright (C) 2017 Analog Devices Inc. > + * > + * Licensed under the GPL-2. > + * > + * Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/2496fc.pdf > + */ > + > +#include <linux/spi/spi.h> > +#include <linux/iio/iio.h> > +#include <linux/iio/driver.h> > +#include <linux/module.h> > +#include <linux/of.h> > + > +#include "ltc2497.h" > + > +struct ltc2496_driverdata { > + /* this must be the first member */ > + struct ltc2497core_driverdata common_ddata; > + struct spi_device *spi; > + > + /* > + * DMA (thus cache coherency maintenance) requires the > + * transfer buffers to live in their own cache lines. > + */ > + unsigned char rxbuf[3] ____cacheline_aligned; > + unsigned char txbuf[3]; > +}; > + > +static int ltc2496_result_and_measure(struct ltc2497core_driverdata *ddata, > + u8 address, int *val) > +{ > + struct ltc2496_driverdata *st = > + container_of(ddata, struct ltc2496_driverdata, common_ddata); > + struct spi_transfer t = { > + .tx_buf = st->txbuf, > + .rx_buf = st->rxbuf, > + .len = sizeof(st->txbuf), > + }; > + int ret; > + > + st->txbuf[0] = LTC2497_ENABLE | address; > + > + ret = spi_sync_transfer(st->spi, &t, 1); > + if (ret < 0) { > + dev_err(&st->spi->dev, "spi_sync_transfer failed: %pe\n", > + ERR_PTR(ret)); > + return ret; > + } > + > + if (val) > + *val = ((st->rxbuf[0] & 0x3f) << 12 | > + st->rxbuf[1] << 4 | st->rxbuf[2] >> 4) - > + (1 << 17); > + > + return 0; > +} > + > +static int ltc2496_probe(struct spi_device *spi) > +{ > + struct iio_dev *indio_dev; > + struct ltc2496_driverdata *st; > + struct device *dev = &spi->dev; > + > + indio_dev = devm_iio_device_alloc(dev, sizeof(*st)); > + if (!indio_dev) > + return -ENOMEM; > + > + st = iio_priv(indio_dev); > + spi_set_drvdata(spi, indio_dev); > + st->spi = spi; > + st->common_ddata.result_and_measure = ltc2496_result_and_measure; > + > + return ltc2497core_probe(dev, indio_dev); > +} > + > +static int ltc2496_remove(struct spi_device *spi) > +{ > + struct iio_dev *indio_dev = spi_get_drvdata(spi); > + > + ltc2497core_remove(indio_dev); > + > + return 0; > +} > + > +static const struct of_device_id ltc2496_of_match[] = { > + { .compatible = "lltc,ltc2496", }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, ltc2496_of_match); > + > +static struct spi_driver ltc2496_driver = { > + .driver = { > + .name = "ltc2496", > + .of_match_table = of_match_ptr(ltc2496_of_match), > + }, > + .probe = ltc2496_probe, > + .remove = ltc2496_remove, > +}; > +module_spi_driver(ltc2496_driver); > + > +MODULE_AUTHOR("Uwe Kleine-König <u.kleine-könig@xxxxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("Linear Technology LTC2496 ADC driver"); > +MODULE_LICENSE("GPL v2");
