| Message ID | 20191111214025.18310-1-u.kleine-koenig@pengutronix.de |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | [1/3] iio: adc: ltc2496: provide device tree binding document | expand |
| Context | Check | Description |
|---|---|---|
| robh/checkpatch | success |
On Mon, 2019-11-11 at 22:40 +0100, Uwe Kleine-König wrote: > The ADC only requires the standard stuff for spi devices and a reference > voltage. > Hey, Thanks for the patch. DT bindings must be in YAML format. But in this case, you can probably extend the existing "Documentation/devicetree/bindings/iio/adc/ltc2497.txt". You don't need to create new file altogether. > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > .../devicetree/bindings/iio/adc/ltc2496.txt | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/adc/ltc2496.txt > > diff --git a/Documentation/devicetree/bindings/iio/adc/ltc2496.txt > b/Documentation/devicetree/bindings/iio/adc/ltc2496.txt > new file mode 100644 > index 000000000000..d44ab45b26ea > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/adc/ltc2496.txt > @@ -0,0 +1,15 @@ > +* Linear Technology / Analog Devices LTC2496 ADC > + > +Required properties: > + - compatible: Must be "lltc,ltc2496" > + - vref-supply: The regulator supply for ADC reference voltage > + - further properties required for spi device nodes according to > + Documentation/devicetree/bindings/spi/spi-controller.yaml > + > +Example: > + ltc2497: adc@76 { > + compatible = "lltc,ltc2496"; > + reg = <0>; > + vref-supply = <<c249x_reg>; > + spi-max-frequency = <2000000>; > + };
Hello Alexandru, On Tue, Nov 12, 2019 at 06:57:49AM +0000, Ardelean, Alexandru wrote: > On Mon, 2019-11-11 at 22:40 +0100, Uwe Kleine-König wrote: > > The ADC only requires the standard stuff for spi devices and a reference > > voltage. > > DT bindings must be in YAML format. Yeah, I noticed this trend. But given that I only saw .txt files for iio, I thought I'd stick to that. > But in this case, you can probably extend the existing > "Documentation/devicetree/bindings/iio/adc/ltc2497.txt". I considered that shortly, but as the ltc2497 is an i2c device and the ltc2496 uses spi I chose to create another simple document instead of complicating the existing one by describing two nearly orthogonal sets of properties. Best regards Uwe
On Mon, 2019-11-11 at 22:40 +0100, Uwe Kleine-König wrote: > This allows to share the data for the ltc2496 driver added in > the next commit that is an SPI variant of the ltc2497. > Hey, For this split, maybe take a look at adxl372-i2c.c & adxl372-spi.c. I think that one is similar to how this split could be. > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > drivers/iio/adc/Makefile | 2 +- > drivers/iio/adc/ltc2497.c | 81 +++++---------------------------------- > drivers/iio/adc/ltc249x.c | 72 ++++++++++++++++++++++++++++++++++ > drivers/iio/adc/ltc249x.h | 10 +++++ > 4 files changed, 93 insertions(+), 72 deletions(-) > create mode 100644 drivers/iio/adc/ltc249x.c > create mode 100644 drivers/iio/adc/ltc249x.h > > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index ef9cc485fb67..660242c2cca7 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -47,7 +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-$(CONFIG_LTC2497) += ltc2497.o > +obj-$(CONFIG_LTC2497) += ltc2497.o ltc249x.o Typically, we name the common/core files "ltc2497-core.o". Or you can leave this unchanged and just add a new "ltc2497-i2c.o" In this case, you also need some new Kconfig symbols. [patch2-note1] And this would be obj-$(CONFIG_LTC2497) += ltc2497.o +obj-$(CONFIG_LTC2497_I2C) += ltc2497-i2c.o Because, the new driver would be: obj-$(CONFIG_LTC2497) += ltc2497.o +obj-$(CONFIG_LTC2497_I2C) += ltc2497- i2c.o +obj-$(CONFIG_LTC2497_SPI) += ltc2497-spi.o So, LTC2496 would go into "ltc2497-spi." > obj-$(CONFIG_MAX1027) += max1027.o > obj-$(CONFIG_MAX11100) += max11100.o > obj-$(CONFIG_MAX1118) += max1118.o > diff --git a/drivers/iio/adc/ltc2497.c b/drivers/iio/adc/ltc2497.c > index 470406032720..e86fe42f1598 100644 > --- a/drivers/iio/adc/ltc2497.c > +++ b/drivers/iio/adc/ltc2497.c > @@ -16,12 +16,7 @@ > #include <linux/of.h> > #include <linux/regulator/consumer.h> > > -#define LTC2497_ENABLE 0xA0 > -#define LTC2497_SGL BIT(4) > -#define LTC2497_DIFF 0 > -#define LTC2497_SIGN BIT(3) > -#define LTC2497_CONFIG_DEFAULT LTC2497_ENABLE > -#define LTC2497_CONVERSION_TIME_MS 150ULL > +#include "ltc249x.h" > > struct ltc2497_st { > struct i2c_client *client; > @@ -41,18 +36,18 @@ static int ltc2497_wait_conv(struct ltc2497_st *st) > > time_elapsed = ktime_ms_delta(ktime_get(), st->time_prev); > > - if (time_elapsed < LTC2497_CONVERSION_TIME_MS) { > + if (time_elapsed < LTC249X_CONVERSION_TIME_MS) { You can leave all LTC2497_xxx macros/definitions unchanged. If LTC2496 has something new, you can add a new LTC2496_specific_xxx definition and use it. > /* delay if conversion time not passed > * since last read or write > */ > if (msleep_interruptible( > - LTC2497_CONVERSION_TIME_MS - time_elapsed)) > + LTC249X_CONVERSION_TIME_MS - time_elapsed)) > return -ERESTARTSYS; > > return 0; > } > > - if (time_elapsed - LTC2497_CONVERSION_TIME_MS <= 0) { > + if (time_elapsed - LTC249X_CONVERSION_TIME_MS <= 0) { > /* We're in automatic mode - > * so the last reading is stil not outdated > */ > @@ -73,11 +68,11 @@ static int ltc2497_read(struct ltc2497_st *st, u8 > address, int *val) > > if (ret || st->addr_prev != address) { > ret = i2c_smbus_write_byte(st->client, > - LTC2497_ENABLE | address); > + LTC249X_ENABLE | address); > if (ret < 0) > return ret; > st->addr_prev = address; > - if (msleep_interruptible(LTC2497_CONVERSION_TIME_MS)) > + if (msleep_interruptible(LTC249X_CONVERSION_TIME_MS)) > return -ERESTARTSYS; > } > ret = i2c_master_recv(client, (char *)&st->buf, 3); > @@ -127,62 +122,6 @@ static int ltc2497_read_raw(struct iio_dev > *indio_dev, > } > } > > -#define LTC2497_CHAN(_chan, _addr, _ds_name) { \ > - .type = IIO_VOLTAGE, \ > - .indexed = 1, \ > - .channel = (_chan), \ > - .address = (_addr | (_chan / 2) | ((_chan & 1) ? LTC2497_SIGN : > 0)), \ > - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ > - .datasheet_name = (_ds_name), \ > -} > - > -#define LTC2497_CHAN_DIFF(_chan, _addr) { \ > - .type = IIO_VOLTAGE, \ > - .indexed = 1, \ > - .channel = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 1 : 0), \ > - .channel2 = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 0 : 1),\ > - .address = (_addr | _chan), \ > - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ > - .differential = 1, \ > -} > - > -static const struct iio_chan_spec ltc2497_channel[] = { > - LTC2497_CHAN(0, LTC2497_SGL, "CH0"), > - LTC2497_CHAN(1, LTC2497_SGL, "CH1"), > - LTC2497_CHAN(2, LTC2497_SGL, "CH2"), > - LTC2497_CHAN(3, LTC2497_SGL, "CH3"), > - LTC2497_CHAN(4, LTC2497_SGL, "CH4"), > - LTC2497_CHAN(5, LTC2497_SGL, "CH5"), > - LTC2497_CHAN(6, LTC2497_SGL, "CH6"), > - LTC2497_CHAN(7, LTC2497_SGL, "CH7"), > - LTC2497_CHAN(8, LTC2497_SGL, "CH8"), > - LTC2497_CHAN(9, LTC2497_SGL, "CH9"), > - LTC2497_CHAN(10, LTC2497_SGL, "CH10"), > - LTC2497_CHAN(11, LTC2497_SGL, "CH11"), > - LTC2497_CHAN(12, LTC2497_SGL, "CH12"), > - LTC2497_CHAN(13, LTC2497_SGL, "CH13"), > - LTC2497_CHAN(14, LTC2497_SGL, "CH14"), > - LTC2497_CHAN(15, LTC2497_SGL, "CH15"), > - LTC2497_CHAN_DIFF(0, LTC2497_DIFF), > - LTC2497_CHAN_DIFF(1, LTC2497_DIFF), > - LTC2497_CHAN_DIFF(2, LTC2497_DIFF), > - LTC2497_CHAN_DIFF(3, LTC2497_DIFF), > - LTC2497_CHAN_DIFF(4, LTC2497_DIFF), > - LTC2497_CHAN_DIFF(5, LTC2497_DIFF), > - LTC2497_CHAN_DIFF(6, LTC2497_DIFF), > - LTC2497_CHAN_DIFF(7, LTC2497_DIFF), > - LTC2497_CHAN_DIFF(0, LTC2497_DIFF | LTC2497_SIGN), > - LTC2497_CHAN_DIFF(1, LTC2497_DIFF | LTC2497_SIGN), > - LTC2497_CHAN_DIFF(2, LTC2497_DIFF | LTC2497_SIGN), > - LTC2497_CHAN_DIFF(3, LTC2497_DIFF | LTC2497_SIGN), > - LTC2497_CHAN_DIFF(4, LTC2497_DIFF | LTC2497_SIGN), > - LTC2497_CHAN_DIFF(5, LTC2497_DIFF | LTC2497_SIGN), > - LTC2497_CHAN_DIFF(6, LTC2497_DIFF | LTC2497_SIGN), > - LTC2497_CHAN_DIFF(7, LTC2497_DIFF | LTC2497_SIGN), > -}; > - > static const struct iio_info ltc2497_info = { > .read_raw = ltc2497_read_raw, > }; > @@ -211,8 +150,8 @@ static int ltc2497_probe(struct i2c_client *client, > indio_dev->name = id->name; > indio_dev->info = <c2497_info; > indio_dev->modes = INDIO_DIRECT_MODE; > - indio_dev->channels = ltc2497_channel; > - indio_dev->num_channels = ARRAY_SIZE(ltc2497_channel); > + indio_dev->channels = ltc249x_channel; > + indio_dev->num_channels = ltc249x_num_channels; > > st->ref = devm_regulator_get(&client->dev, "vref"); > if (IS_ERR(st->ref)) > @@ -231,11 +170,11 @@ static int ltc2497_probe(struct i2c_client *client, > } > } > > - ret = i2c_smbus_write_byte(st->client, LTC2497_CONFIG_DEFAULT); > + ret = i2c_smbus_write_byte(st->client, LTC249X_CONFIG_DEFAULT); > if (ret < 0) > goto err_array_unregister; > > - st->addr_prev = LTC2497_CONFIG_DEFAULT; > + st->addr_prev = LTC249X_CONFIG_DEFAULT; > st->time_prev = ktime_get(); > > ret = iio_device_register(indio_dev); > diff --git a/drivers/iio/adc/ltc249x.c b/drivers/iio/adc/ltc249x.c > new file mode 100644 > index 000000000000..571fce7cc808 > --- /dev/null > +++ b/drivers/iio/adc/ltc249x.c > @@ -0,0 +1,72 @@ > +// SPDX-License-Identifier: GPL-2.0-only > + > +#include <linux/iio/iio.h> > +#include <linux/iio/driver.h> > +#include <linux/module.h> > + > +#define LTC249X_SGL BIT(4) > +#define LTC249X_DIFF 0 > +#define LTC249X_SIGN BIT(3) > + > +#define LTC249X_CHAN(_chan, _addr, _ds_name) { \ > + .type = IIO_VOLTAGE, \ > + .indexed = 1, \ > + .channel = (_chan), \ > + .address = (_addr | (_chan / 2) | ((_chan & 1) ? LTC249X_SIGN : > 0)), \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ > + .datasheet_name = (_ds_name), \ > +} > + > +#define LTC249X_CHAN_DIFF(_chan, _addr) { \ > + .type = IIO_VOLTAGE, \ > + .indexed = 1, \ > + .channel = (_chan) * 2 + ((_addr) & LTC249X_SIGN ? 1 : 0), \ > + .channel2 = (_chan) * 2 + ((_addr) & LTC249X_SIGN ? 0 : 1),\ > + .address = (_addr | _chan), \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ > + .differential = 1, \ > +} > + > +const struct iio_chan_spec ltc249x_channel[] = { > + LTC249X_CHAN(0, LTC249X_SGL, "CH0"), > + LTC249X_CHAN(1, LTC249X_SGL, "CH1"), > + LTC249X_CHAN(2, LTC249X_SGL, "CH2"), > + LTC249X_CHAN(3, LTC249X_SGL, "CH3"), > + LTC249X_CHAN(4, LTC249X_SGL, "CH4"), > + LTC249X_CHAN(5, LTC249X_SGL, "CH5"), > + LTC249X_CHAN(6, LTC249X_SGL, "CH6"), > + LTC249X_CHAN(7, LTC249X_SGL, "CH7"), > + LTC249X_CHAN(8, LTC249X_SGL, "CH8"), > + LTC249X_CHAN(9, LTC249X_SGL, "CH9"), > + LTC249X_CHAN(10, LTC249X_SGL, "CH10"), > + LTC249X_CHAN(11, LTC249X_SGL, "CH11"), > + LTC249X_CHAN(12, LTC249X_SGL, "CH12"), > + LTC249X_CHAN(13, LTC249X_SGL, "CH13"), > + LTC249X_CHAN(14, LTC249X_SGL, "CH14"), > + LTC249X_CHAN(15, LTC249X_SGL, "CH15"), > + LTC249X_CHAN_DIFF(0, LTC249X_DIFF), > + LTC249X_CHAN_DIFF(1, LTC249X_DIFF), > + LTC249X_CHAN_DIFF(2, LTC249X_DIFF), > + LTC249X_CHAN_DIFF(3, LTC249X_DIFF), > + LTC249X_CHAN_DIFF(4, LTC249X_DIFF), > + LTC249X_CHAN_DIFF(5, LTC249X_DIFF), > + LTC249X_CHAN_DIFF(6, LTC249X_DIFF), > + LTC249X_CHAN_DIFF(7, LTC249X_DIFF), > + LTC249X_CHAN_DIFF(0, LTC249X_DIFF | LTC249X_SIGN), > + LTC249X_CHAN_DIFF(1, LTC249X_DIFF | LTC249X_SIGN), > + LTC249X_CHAN_DIFF(2, LTC249X_DIFF | LTC249X_SIGN), > + LTC249X_CHAN_DIFF(3, LTC249X_DIFF | LTC249X_SIGN), > + LTC249X_CHAN_DIFF(4, LTC249X_DIFF | LTC249X_SIGN), > + LTC249X_CHAN_DIFF(5, LTC249X_DIFF | LTC249X_SIGN), > + LTC249X_CHAN_DIFF(6, LTC249X_DIFF | LTC249X_SIGN), > + LTC249X_CHAN_DIFF(7, LTC249X_DIFF | LTC249X_SIGN), > +}; > +EXPORT_SYMBOL_NS_GPL(ltc249x_channel, LTC249X); Maybe leave these channel definitions in "ltc2497.o" file [which can be the common one]. Instead of exporting these, maybe create a "int ltc2497_core_probe(struct device *dev)" function. and add it in the "ltc2497.h" file. You can call it with "ltc2497_core_probe(&spi->dev)" and "ltc2497_core_probe(&client->dev)" The beauty of this approach is that you also allocate the IIO device in the common code. > + > +const int ltc249x_num_channels = ARRAY_SIZE(ltc249x_channel); > +EXPORT_SYMBOL_NS_GPL(ltc249x_num_channels, LTC249X); > + > +MODULE_DESCRIPTION("common code for LTC2496/LTC2497 drivers"); > +MODULE_LICENSE("GPL v2"); > diff --git a/drivers/iio/adc/ltc249x.h b/drivers/iio/adc/ltc249x.h > new file mode 100644 > index 000000000000..dac8b5ed0ecf > --- /dev/null > +++ b/drivers/iio/adc/ltc249x.h > @@ -0,0 +1,10 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > + > +#define LTC249X_ENABLE 0xA0 > +#define LTC249X_CONFIG_DEFAULT LTC249X_ENABLE > +#define LTC249X_CONVERSION_TIME_MS 150ULL > + > +extern const struct iio_chan_spec ltc249x_channel[]; > +extern const int ltc249x_num_channels; > + > +MODULE_IMPORT_NS(LTC249X);
On Mon, 2019-11-11 at 22:40 +0100, Uwe Kleine-König wrote: > This chip is similar to the LTC2497 ADC, it just uses SPI instead of I2C > and so has a slightly different protocol. The channel definitions are > shared between the two drivers. Much of this code is duplicated from the i2c/base ltc2497.o driver. I would leave most of this code in the base/common driver and export the i2c/spi read hooks. You can check [as an example] the ad7606 driver. That one passes some bus_ops struct from the SPI & Parallel drivers to the common probe. I agree that regmap isn't usable here, but a bus_ops struct [that is defined in ltc2497.h] should be doable. Thanks Alex > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > drivers/iio/adc/Kconfig | 10 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/ltc2496.c | 208 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 219 insertions(+) > create mode 100644 drivers/iio/adc/ltc2496.c > > 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 Regarding [patch2-note1], this Kconfig symbols would be LTC2497_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 Regarding [patch2-note1], this Kconfig symbols would become LTC2497_I2C. And a new config LTC2497 could be added, but without any title, so that it cannot be selected in menuconfig. > tristate "Linear Technology LTC2497 ADC driver" > depends on I2C > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index 660242c2cca7..afe2b6db4a5e 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-$(CONFIG_LTC2496) += ltc2496.o ltc249x.o > obj-$(CONFIG_LTC2497) += ltc2497.o ltc249x.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..0b0a7aa8987f > --- /dev/null > +++ b/drivers/iio/adc/ltc2496.c > @@ -0,0 +1,208 @@ > +// 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/delay.h> > +#include <linux/spi/spi.h> > +#include <linux/iio/iio.h> > +#include <linux/iio/driver.h> > +#include <linux/iio/sysfs.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/regulator/consumer.h> > + > +#include "ltc249x.h" > + > +struct ltc2496_st { > + struct spi_device *spi; > + struct regulator *ref; > + ktime_t time_prev; > + u8 addr_prev; > +}; > + > +static int ltc2496_wait_conv(struct ltc2496_st *st) > +{ > + s64 time_elapsed; > + > + time_elapsed = ktime_ms_delta(ktime_get(), st->time_prev); > + > + if (time_elapsed < LTC249X_CONVERSION_TIME_MS) { > + /* delay if conversion time not passed > + * since last read or write > + */ > + if (msleep_interruptible( > + LTC249X_CONVERSION_TIME_MS - time_elapsed)) > + return -ERESTARTSYS; > + > + return 0; > + } > + > + if (time_elapsed - LTC249X_CONVERSION_TIME_MS <= 0) { > + /* We're in automatic mode - > + * so the last reading is still not outdated > + */ > + return 0; > + } > + > + return 1; > +} > + > +static int ltc2496_read(struct ltc2496_st *st, u8 address, int *val) > +{ > + struct spi_device *spi = st->spi; > + int ret; > + unsigned char txbuf[3] = { LTC249X_ENABLE | address, }; > + unsigned char rxbuf[3]; > + struct spi_transfer t = { > + .tx_buf = txbuf, > + .rx_buf = rxbuf, > + .len = sizeof(txbuf), > + }; > + > + ret = ltc2496_wait_conv(st); > + if (ret < 0) > + return ret; > + > + if (ret || st->addr_prev != address) { > + ret = spi_sync_transfer(spi, &t, 1); > + if (ret < 0) > + return ret; > + st->addr_prev = address; > + if (msleep_interruptible(LTC249X_CONVERSION_TIME_MS)) > + return -ERESTARTSYS; > + } > + > + ret = spi_sync_transfer(spi, &t, 1); > + if (ret < 0) { > + dev_err(&spi->dev, "spi_sync_transfer failed\n"); > + return ret; > + } > + st->time_prev = ktime_get(); > + > + /* convert and shift the result, > + * and finally convert from offset binary to signed integer > + */ > + *val = ((rxbuf[0] & 0x3f) << 12 | rxbuf[1] << 4 | rxbuf[2] >> 4) > + - (1 << 17); > + > + return ret; > +} > + int *val, int *val2, long mask) > +{ > + struct ltc2496_st *st = iio_priv(indio_dev); > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + mutex_lock(&indio_dev->mlock); > + ret = ltc2496_read(st, chan->address, val); > + mutex_unlock(&indio_dev->mlock); > + if (ret < 0) > + return ret; > + > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_SCALE: > + ret = regulator_get_voltage(st->ref); > + if (ret < 0) > + return ret; > + > + *val = ret / 1000; > + *val2 = 17; > + > + return IIO_VAL_FRACTIONAL_LOG2; > + > + default: > + return -EINVAL; > + } > +} > + > +static const struct iio_info ltc2496_info = { > + .read_raw = ltc2496_read_raw, > +}; > + > +static int ltc2496_probe(struct spi_device *spi) > +{ > + struct iio_dev *indio_dev; > + struct ltc2496_st *st; > + int ret; > + > + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); > + if (!indio_dev) > + return -ENOMEM; > + > + st = iio_priv(indio_dev); > + spi_set_drvdata(spi, indio_dev); > + st->spi = spi; > + > + indio_dev->dev.parent = &spi->dev; > + indio_dev->name = "ltc2496"; > + indio_dev->info = <c2496_info; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = ltc249x_channel; > + indio_dev->num_channels = ltc249x_num_channels; > + > + st->ref = devm_regulator_get(&spi->dev, "vref"); > + if (IS_ERR(st->ref)) > + return PTR_ERR(st->ref); > + > + ret = regulator_enable(st->ref); > + if (ret < 0) > + return ret; > + > + st->addr_prev = 0; > + st->time_prev = ktime_get(); > + > + ret = iio_device_register(indio_dev); > + if (ret < 0) > + goto err_regulator_disable; > + > + return 0; > + > +err_regulator_disable: > + regulator_disable(st->ref); > + > + return ret; > +} > + > +static int ltc2496_remove(struct spi_device *spi) > +{ > + struct iio_dev *indio_dev = spi_get_drvdata(spi); > + struct ltc2496_st *st = iio_priv(indio_dev); > + > + iio_device_unregister(indio_dev); > + regulator_disable(st->ref); > + > + 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@pengutronix.de>"); > +MODULE_DESCRIPTION("Linear Technology LTC2496 ADC driver"); > +MODULE_LICENSE("GPL v2");
On Tue, 2019-11-12 at 08:04 +0100, Uwe Kleine-König wrote: > [External] > > Hello Alexandru, > > On Tue, Nov 12, 2019 at 06:57:49AM +0000, Ardelean, Alexandru wrote: > > On Mon, 2019-11-11 at 22:40 +0100, Uwe Kleine-König wrote: > > > The ADC only requires the standard stuff for spi devices and a > > > reference > > > voltage. > > > > DT bindings must be in YAML format. > > Yeah, I noticed this trend. But given that I only saw .txt files for > iio, I thought I'd stick to that. > > > But in this case, you can probably extend the existing > > "Documentation/devicetree/bindings/iio/adc/ltc2497.txt". > > I considered that shortly, but as the ltc2497 is an i2c device and the > ltc2496 uses spi I chose to create another simple document instead of > complicating the existing one by describing two nearly orthogonal sets > of properties. There are dt-bindings that cover both SPI & I2C. I think ADXL372 does that too. > > Best regards > Uwe >
On Tue, 12 Nov 2019 11:56:52 +0000 "Ardelean, Alexandru" <alexandru.Ardelean@analog.com> wrote: > On Tue, 2019-11-12 at 08:04 +0100, Uwe Kleine-König wrote: > > [External] > > > > Hello Alexandru, > > > > On Tue, Nov 12, 2019 at 06:57:49AM +0000, Ardelean, Alexandru wrote: > > > On Mon, 2019-11-11 at 22:40 +0100, Uwe Kleine-König wrote: > > > > The ADC only requires the standard stuff for spi devices and a > > > > reference > > > > voltage. > > > > > > DT bindings must be in YAML format. > > > > Yeah, I noticed this trend. But given that I only saw .txt files for > > iio, I thought I'd stick to that. > > > > > But in this case, you can probably extend the existing > > > "Documentation/devicetree/bindings/iio/adc/ltc2497.txt". > > > > I considered that shortly, but as the ltc2497 is an i2c device and the > > ltc2496 uses spi I chose to create another simple document instead of > > complicating the existing one by describing two nearly orthogonal sets > > of properties. > > There are dt-bindings that cover both SPI & I2C. > I think ADXL372 does that too. True, but in that case no real choice as the same part does both bus types. Here it's probably cleaner to just have a second document. Thanks, Jonathan > > > > > > Best regards > > Uwe > >
diff --git a/Documentation/devicetree/bindings/iio/adc/ltc2496.txt b/Documentation/devicetree/bindings/iio/adc/ltc2496.txt new file mode 100644 index 000000000000..d44ab45b26ea --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/ltc2496.txt @@ -0,0 +1,15 @@ +* Linear Technology / Analog Devices LTC2496 ADC + +Required properties: + - compatible: Must be "lltc,ltc2496" + - vref-supply: The regulator supply for ADC reference voltage + - further properties required for spi device nodes according to + Documentation/devicetree/bindings/spi/spi-controller.yaml + +Example: + ltc2497: adc@76 { + compatible = "lltc,ltc2496"; + reg = <0>; + vref-supply = <<c249x_reg>; + spi-max-frequency = <2000000>; + };
The ADC only requires the standard stuff for spi devices and a reference voltage. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> --- .../devicetree/bindings/iio/adc/ltc2496.txt | 15 +++++++++++++++ 1 file changed, 15 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/adc/ltc2496.txt