* [PATCH v7 0/2] Maxim MAX1241 driver @ 2020-04-03 12:13 Alexandru Lazar 2020-04-03 12:13 ` [PATCH v7 1/2] dt-bindings: iio: adc: Add MAX1241 bindings Alexandru Lazar 2020-04-03 12:13 ` [PATCH v7 2/2] iio: adc: Add MAX1241 driver Alexandru Lazar 0 siblings, 2 replies; 9+ messages in thread From: Alexandru Lazar @ 2020-04-03 12:13 UTC (permalink / raw) To: linux-iio Cc: devicetree, jic23, knaack.h, lars, pmeerw, robh+dt, mark.rutland, Alexandru Lazar Hi everyone, Here's version 7 of a patch series which adds support for the Maxim MAX1241, a 12-bit, single-channel, SPI-connected ADC. Changelog so far: v7: * Add datasheet tag to commit message v6: * Add separate cleanup actions for vdd and vref regulators respectively * Change shdn pin name to shutdown. shdn is what the datasheet calls it but "shutdown" seems to be semi-standard, at least in the bindings (Rob orriginally suggested that I change the name in the docs. Figured it made zero sense to have it bear another name in the code) * Dropped maxItems property in vref binding, made binding dual-licensed * Changed name of spi node in binding example v5: * Add vdd supply binding * Reorder include headers -- one of them had escaped the long mechanized hand of the Alphabetron * Drop scan_index and scan_type from channel spec, as the driver doesn't support buffered modes * Drop a useless initialization of a local variable in probe function * Revise dt-bindings patch subject line, revise maintainer and copyright to match the Signed-off: string, drop reference to driver from bindings description * Various readability/cosmetic fixes v4: * Dropped explicit documentation of SPI reg property * Reordered patch series so that dt bindings come first v3: * Fixed silly copy-paste error in Kconfig description v2: * Removed useeless header includes * Dropped needlessly verbose stuff in _read and _probe functions * Dropped useless GPL notice * Lowered log level of shdn pin status in probe function, now it's dev_dbg * Added proper error checking for the GPIO shutdown pin * remove now always returns zero (man, I've been wrong about this for *years* now...) * Added regulator disable action, cleanup is now handled via devm * Drop delay_usecs, use delay.value, delay.unit * Drop config_of, of_match_ptr call * Dropped IIO_BUFFER, IIO_TRIGGERED_BUFFER dependencies, set SPI_MASTER as dependency, fix indenting. * DT binding: use correct id, add reg description (looks pretty standard), dropped spi-max-frequency, fixed dt_binding_check complaints (oops!) Alexandru Lazar (2): dt-bindings: iio: adc: Add MAX1241 bindings iio: adc: Add MAX1241 driver .../bindings/iio/adc/maxim,max1241.yaml | 64 +++++ drivers/iio/adc/Kconfig | 10 + drivers/iio/adc/Makefile | 1 + drivers/iio/adc/max1241.c | 227 ++++++++++++++++++ 4 files changed, 302 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml create mode 100644 drivers/iio/adc/max1241.c -- 2.20.1 ^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v7 1/2] dt-bindings: iio: adc: Add MAX1241 bindings 2020-04-03 12:13 [PATCH v7 0/2] Maxim MAX1241 driver Alexandru Lazar @ 2020-04-03 12:13 ` Alexandru Lazar 2020-04-04 16:56 ` Jonathan Cameron 2020-04-14 17:45 ` Rob Herring 2020-04-03 12:13 ` [PATCH v7 2/2] iio: adc: Add MAX1241 driver Alexandru Lazar 1 sibling, 2 replies; 9+ messages in thread From: Alexandru Lazar @ 2020-04-03 12:13 UTC (permalink / raw) To: linux-iio Cc: devicetree, jic23, knaack.h, lars, pmeerw, robh+dt, mark.rutland, Alexandru Lazar Add device-tree bindings documentation for the MAX1241 device driver. Signed-off-by: Alexandru Lazar <alazar@startmail.com> --- .../bindings/iio/adc/maxim,max1241.yaml | 64 +++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml diff --git a/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml b/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml new file mode 100644 index 000000000000..7da9e4153ac1 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml @@ -0,0 +1,64 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +# Copyright 2020 Alexandru Lazar +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/iio/adc/maxim,max1241.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Maxim MAX1241 12-bit, single-channel analog to digital converter + +maintainers: + - Alexandru Lazar <alazar@startmail.com> + +description: | + Bindings for the max1241 12-bit, single-channel ADC device. Datasheet + can be found at: + https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf + +properties: + compatible: + enum: + - maxim,max1241 + + reg: + maxItems: 1 + + vdd-supply: + description: + Device tree identifier of the regulator that powers the ADC. + + vref-supply: + description: + Device tree identifier of the regulator that provides the external + reference voltage. + maxItems: 1 + + shutdown-gpios: + description: + GPIO spec for the GPIO pin connected to the ADC's /SHDN pin. If + specified, the /SHDN pin will be asserted between conversions, + thus enabling power-down mode. + maxItems: 1 + +required: + - compatible + - reg + - vdd-supply + - vref-supply + +examples: + - | + #include <dt-bindings/gpio/gpio.h> + spi { + #address-cells = <1>; + #size-cells = <0>; + + adc@0 { + compatible = "maxim,max1241"; + reg = <0>; + vdd-supply = <&adc_vdd>; + vref-supply = <&adc_vref>; + spi-max-frequency = <1000000>; + shutdown-gpios = <&gpio 26 1>; + }; + }; -- 2.20.1 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v7 1/2] dt-bindings: iio: adc: Add MAX1241 bindings 2020-04-03 12:13 ` [PATCH v7 1/2] dt-bindings: iio: adc: Add MAX1241 bindings Alexandru Lazar @ 2020-04-04 16:56 ` Jonathan Cameron 2020-04-14 17:45 ` Rob Herring 1 sibling, 0 replies; 9+ messages in thread From: Jonathan Cameron @ 2020-04-04 16:56 UTC (permalink / raw) To: Alexandru Lazar Cc: linux-iio, devicetree, knaack.h, lars, pmeerw, robh+dt, mark.rutland On Fri, 3 Apr 2020 15:13:22 +0300 Alexandru Lazar <alazar@startmail.com> wrote: > Add device-tree bindings documentation for the MAX1241 device driver. > > Signed-off-by: Alexandru Lazar <alazar@startmail.com> One trivial thing inline. I'll fix that up and apply, but not in a form that can't be rebased - so I can add DT review if Rob wants to take another look. Thanks, Jonathan > --- > .../bindings/iio/adc/maxim,max1241.yaml | 64 +++++++++++++++++++ > 1 file changed, 64 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml > > diff --git a/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml b/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml > new file mode 100644 > index 000000000000..7da9e4153ac1 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml > @@ -0,0 +1,64 @@ > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) > +# Copyright 2020 Alexandru Lazar > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/iio/adc/maxim,max1241.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Maxim MAX1241 12-bit, single-channel analog to digital converter > + > +maintainers: > + - Alexandru Lazar <alazar@startmail.com> > + > +description: | > + Bindings for the max1241 12-bit, single-channel ADC device. Datasheet > + can be found at: > + https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf > + > +properties: > + compatible: > + enum: > + - maxim,max1241 > + > + reg: > + maxItems: 1 > + > + vdd-supply: > + description: > + Device tree identifier of the regulator that powers the ADC. > + > + vref-supply: > + description: > + Device tree identifier of the regulator that provides the external > + reference voltage. I believe this is always one anyway so not needed. > + maxItems: 1 > + > + shutdown-gpios: > + description: > + GPIO spec for the GPIO pin connected to the ADC's /SHDN pin. If > + specified, the /SHDN pin will be asserted between conversions, > + thus enabling power-down mode. > + maxItems: 1 > + > +required: > + - compatible > + - reg > + - vdd-supply > + - vref-supply > + > +examples: > + - | > + #include <dt-bindings/gpio/gpio.h> > + spi { > + #address-cells = <1>; > + #size-cells = <0>; > + > + adc@0 { > + compatible = "maxim,max1241"; > + reg = <0>; > + vdd-supply = <&adc_vdd>; > + vref-supply = <&adc_vref>; > + spi-max-frequency = <1000000>; > + shutdown-gpios = <&gpio 26 1>; > + }; > + }; ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v7 1/2] dt-bindings: iio: adc: Add MAX1241 bindings 2020-04-03 12:13 ` [PATCH v7 1/2] dt-bindings: iio: adc: Add MAX1241 bindings Alexandru Lazar 2020-04-04 16:56 ` Jonathan Cameron @ 2020-04-14 17:45 ` Rob Herring 2020-04-14 18:10 ` Jonathan Cameron 1 sibling, 1 reply; 9+ messages in thread From: Rob Herring @ 2020-04-14 17:45 UTC (permalink / raw) To: Alexandru Lazar Cc: linux-iio, devicetree, jic23, knaack.h, lars, pmeerw, robh+dt, mark.rutland, Alexandru Lazar On Fri, 3 Apr 2020 15:13:22 +0300, Alexandru Lazar wrote: > Add device-tree bindings documentation for the MAX1241 device driver. > > Signed-off-by: Alexandru Lazar <alazar@startmail.com> > --- > .../bindings/iio/adc/maxim,max1241.yaml | 64 +++++++++++++++++++ > 1 file changed, 64 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml > Reviewed-by: Rob Herring <robh@kernel.org> ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v7 1/2] dt-bindings: iio: adc: Add MAX1241 bindings 2020-04-14 17:45 ` Rob Herring @ 2020-04-14 18:10 ` Jonathan Cameron 0 siblings, 0 replies; 9+ messages in thread From: Jonathan Cameron @ 2020-04-14 18:10 UTC (permalink / raw) To: Rob Herring Cc: Alexandru Lazar, linux-iio, devicetree, knaack.h, lars, pmeerw, robh+dt, mark.rutland On Tue, 14 Apr 2020 12:45:03 -0500 Rob Herring <robh@kernel.org> wrote: > On Fri, 3 Apr 2020 15:13:22 +0300, Alexandru Lazar wrote: > > Add device-tree bindings documentation for the MAX1241 device driver. > > > > Signed-off-by: Alexandru Lazar <alazar@startmail.com> > > --- > > .../bindings/iio/adc/maxim,max1241.yaml | 64 +++++++++++++++++++ > > 1 file changed, 64 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml > > > > Reviewed-by: Rob Herring <robh@kernel.org> Added. Thanks Rob! Jonathan ^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v7 2/2] iio: adc: Add MAX1241 driver 2020-04-03 12:13 [PATCH v7 0/2] Maxim MAX1241 driver Alexandru Lazar 2020-04-03 12:13 ` [PATCH v7 1/2] dt-bindings: iio: adc: Add MAX1241 bindings Alexandru Lazar @ 2020-04-03 12:13 ` Alexandru Lazar 2020-04-03 14:20 ` Andy Shevchenko 1 sibling, 1 reply; 9+ messages in thread From: Alexandru Lazar @ 2020-04-03 12:13 UTC (permalink / raw) To: linux-iio Cc: devicetree, jic23, knaack.h, lars, pmeerw, robh+dt, mark.rutland, Alexandru Lazar, Alexandru Ardelean Add driver for the Maxim MAX1241 12-bit, single-channel ADC. Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Signed-off-by: Alexandru Lazar <alazar@startmail.com> --- drivers/iio/adc/Kconfig | 10 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/max1241.c | 227 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 238 insertions(+) create mode 100644 drivers/iio/adc/max1241.c diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 5d8540b7b427..55f6462cd93f 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -566,6 +566,16 @@ 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_MASTER + help + Say yes here to build support for Maxim max1241 12-bit, single-channel + ADC. + + To compile this driver as a module, choose M here: the module will be + called max1241. + 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..541939c7abca --- /dev/null +++ b/drivers/iio/adc/max1241.c @@ -0,0 +1,227 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * MAX1241 low-power, 12-bit serial ADC + * + * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf + */ + +#include <linux/delay.h> +#include <linux/gpio/consumer.h> +#include <linux/iio/iio.h> +#include <linux/module.h> +#include <linux/regulator/consumer.h> +#include <linux/spi/spi.h> + +#define MAX1241_VAL_MASK GENMASK(11, 0) +#define MAX1241_SHUTDOWN_DELAY_USEC 4 + +enum max1241_id { + max1241, +}; + +struct max1241 { + struct spi_device *spi; + struct mutex lock; + struct regulator *vdd; + struct regulator *vref; + struct gpio_desc *shutdown; + + __be16 data ____cacheline_aligned; +}; + +static const struct iio_chan_spec max1241_channels[] = { + { + .type = IIO_VOLTAGE, + .indexed = 1, + .channel = 0, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + }, +}; + +static int max1241_read(struct max1241 *adc) +{ + struct spi_transfer xfers[] = { + /* + * Begin conversion by bringing /CS low for at least + * tconv us. + */ + { + .len = 0, + .delay.value = 8, + .delay.unit = SPI_DELAY_UNIT_USECS, + }, + /* + * Then read two bytes of data in our RX buffer. + */ + { + .rx_buf = &adc->data, + .len = 2, + }, + }; + + return spi_sync_transfer(adc->spi, xfers, ARRAY_SIZE(xfers)); +} + +static int max1241_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + int ret, vref_uV; + struct max1241 *adc = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + mutex_lock(&adc->lock); + + if (adc->shutdown) { + gpiod_set_value(adc->shutdown, 0); + udelay(MAX1241_SHUTDOWN_DELAY_USEC); + ret = max1241_read(adc); + gpiod_set_value(adc->shutdown, 1); + } else + ret = max1241_read(adc); + + if (ret) { + mutex_unlock(&adc->lock); + return ret; + } + + *val = (be16_to_cpu(adc->data) >> 3) & MAX1241_VAL_MASK; + + mutex_unlock(&adc->lock); + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + vref_uV = regulator_get_voltage(adc->vref); + + if (vref_uV < 0) + return vref_uV; + + *val = vref_uV / 1000; + *val2 = 12; + + return IIO_VAL_FRACTIONAL_LOG2; + default: + return -EINVAL; + } +} + +static const struct iio_info max1241_info = { + .read_raw = max1241_read_raw, +}; + +static void max1241_disable_vdd_action(void *data) +{ + struct max1241 *adc = data; + struct device *dev = &adc->spi->dev; + int err; + + err = regulator_disable(adc->vdd); + if (err) + dev_err(dev, "could not disable vdd regulator.\n"); +} + +static void max1241_disable_vref_action(void *data) +{ + struct max1241 *adc = data; + struct device *dev = &adc->spi->dev; + int err; + + err = regulator_disable(adc->vref); + if (err) + dev_err(dev, "could not disable vref regulator.\n"); +} + +static int max1241_probe(struct spi_device *spi) +{ + struct device *dev = &spi->dev; + struct iio_dev *indio_dev; + struct max1241 *adc; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*adc)); + if (!indio_dev) + return -ENOMEM; + + adc = iio_priv(indio_dev); + adc->spi = spi; + mutex_init(&adc->lock); + + spi_set_drvdata(spi, indio_dev); + + adc->vdd = devm_regulator_get(dev, "vdd"); + if (IS_ERR(adc->vdd)) { + dev_err(dev, "failed to get vdd regulator\n"); + return PTR_ERR(adc->vdd); + } + + ret = regulator_enable(adc->vdd); + if (ret) + return ret; + + ret = devm_add_action_or_reset(dev, max1241_disable_vdd_action, adc); + if (ret) { + dev_err(dev, "could not set up vdd regulator cleanup action\n"); + return ret; + } + + adc->vref = devm_regulator_get(dev, "vref"); + if (IS_ERR(adc->vref)) { + dev_err(dev, "failed to get vref regulator\n"); + return PTR_ERR(adc->vref); + } + + ret = regulator_enable(adc->vref); + if (ret) + return ret; + + ret = devm_add_action_or_reset(dev, max1241_disable_vref_action, adc); + if (ret) { + dev_err(dev, "could not set up vref regulator cleanup action\n"); + return ret; + } + + adc->shutdown = devm_gpiod_get_optional(dev, "shutdown", + GPIOD_OUT_HIGH); + if (IS_ERR(adc->shutdown)) + return PTR_ERR(adc->shutdown); + + if (adc->shutdown) + dev_dbg(dev, "shutdown pin passed, low-power mode enabled"); + else + dev_dbg(dev, "no shutdown pin passed, low-power mode disabled"); + + indio_dev->name = spi_get_device_id(spi)->name; + indio_dev->dev.parent = dev; + indio_dev->info = &max1241_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = max1241_channels; + indio_dev->num_channels = ARRAY_SIZE(max1241_channels); + + return devm_iio_device_register(dev, indio_dev); +} + +static const struct spi_device_id max1241_id[] = { + { "max1241", max1241 }, + {} +}; + +static const struct of_device_id max1241_dt_ids[] = { + { .compatible = "maxim,max1241" }, + {} +}; +MODULE_DEVICE_TABLE(of, max1241_dt_ids); + +static struct spi_driver max1241_spi_driver = { + .driver = { + .name = "max1241", + .of_match_table = max1241_dt_ids, + }, + .probe = max1241_probe, + .id_table = max1241_id, +}; +module_spi_driver(max1241_spi_driver); + +MODULE_AUTHOR("Alexandru Lazar <alazar@startmail.com>"); +MODULE_DESCRIPTION("MAX1241 ADC driver"); +MODULE_LICENSE("GPL v2"); -- 2.20.1 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v7 2/2] iio: adc: Add MAX1241 driver 2020-04-03 12:13 ` [PATCH v7 2/2] iio: adc: Add MAX1241 driver Alexandru Lazar @ 2020-04-03 14:20 ` Andy Shevchenko 2020-04-03 16:21 ` Alexandru Lazar 0 siblings, 1 reply; 9+ messages in thread From: Andy Shevchenko @ 2020-04-03 14:20 UTC (permalink / raw) To: Alexandru Lazar Cc: linux-iio, devicetree, Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen, Peter Meerwald, Rob Herring, Mark Rutland, Alexandru Ardelean On Fri, Apr 3, 2020 at 3:09 PM Alexandru Lazar <alazar@startmail.com> wrote: > > Add driver for the Maxim MAX1241 12-bit, single-channel ADC. > FWIW, Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf > No blank line, but this can be fixed by maintainer, I think. > Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com> > Signed-off-by: Alexandru Lazar <alazar@startmail.com> > --- > drivers/iio/adc/Kconfig | 10 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/max1241.c | 227 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 238 insertions(+) > create mode 100644 drivers/iio/adc/max1241.c > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 5d8540b7b427..55f6462cd93f 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -566,6 +566,16 @@ 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_MASTER > + help > + Say yes here to build support for Maxim max1241 12-bit, single-channel > + ADC. > + > + To compile this driver as a module, choose M here: the module will be > + called max1241. > + > 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..541939c7abca > --- /dev/null > +++ b/drivers/iio/adc/max1241.c > @@ -0,0 +1,227 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * MAX1241 low-power, 12-bit serial ADC > + * > + * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf > + */ > + > +#include <linux/delay.h> > +#include <linux/gpio/consumer.h> > +#include <linux/iio/iio.h> > +#include <linux/module.h> > +#include <linux/regulator/consumer.h> > +#include <linux/spi/spi.h> > + > +#define MAX1241_VAL_MASK GENMASK(11, 0) > +#define MAX1241_SHUTDOWN_DELAY_USEC 4 > + > +enum max1241_id { > + max1241, > +}; > + > +struct max1241 { > + struct spi_device *spi; > + struct mutex lock; > + struct regulator *vdd; > + struct regulator *vref; > + struct gpio_desc *shutdown; > + > + __be16 data ____cacheline_aligned; > +}; > + > +static const struct iio_chan_spec max1241_channels[] = { > + { > + .type = IIO_VOLTAGE, > + .indexed = 1, > + .channel = 0, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE), > + }, > +}; > + > +static int max1241_read(struct max1241 *adc) > +{ > + struct spi_transfer xfers[] = { > + /* > + * Begin conversion by bringing /CS low for at least > + * tconv us. > + */ > + { > + .len = 0, > + .delay.value = 8, > + .delay.unit = SPI_DELAY_UNIT_USECS, > + }, > + /* > + * Then read two bytes of data in our RX buffer. > + */ > + { > + .rx_buf = &adc->data, > + .len = 2, > + }, > + }; > + > + return spi_sync_transfer(adc->spi, xfers, ARRAY_SIZE(xfers)); > +} > + > +static int max1241_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + int ret, vref_uV; > + struct max1241 *adc = iio_priv(indio_dev); > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + mutex_lock(&adc->lock); > + > + if (adc->shutdown) { > + gpiod_set_value(adc->shutdown, 0); > + udelay(MAX1241_SHUTDOWN_DELAY_USEC); > + ret = max1241_read(adc); > + gpiod_set_value(adc->shutdown, 1); > + } else > + ret = max1241_read(adc); > + > + if (ret) { > + mutex_unlock(&adc->lock); > + return ret; > + } > + > + *val = (be16_to_cpu(adc->data) >> 3) & MAX1241_VAL_MASK; > + > + mutex_unlock(&adc->lock); > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + vref_uV = regulator_get_voltage(adc->vref); > + > + if (vref_uV < 0) > + return vref_uV; > + > + *val = vref_uV / 1000; > + *val2 = 12; > + > + return IIO_VAL_FRACTIONAL_LOG2; > + default: > + return -EINVAL; > + } > +} > + > +static const struct iio_info max1241_info = { > + .read_raw = max1241_read_raw, > +}; > + > +static void max1241_disable_vdd_action(void *data) > +{ > + struct max1241 *adc = data; > + struct device *dev = &adc->spi->dev; > + int err; > + > + err = regulator_disable(adc->vdd); > + if (err) > + dev_err(dev, "could not disable vdd regulator.\n"); > +} > + > +static void max1241_disable_vref_action(void *data) > +{ > + struct max1241 *adc = data; > + struct device *dev = &adc->spi->dev; > + int err; > + > + err = regulator_disable(adc->vref); > + if (err) > + dev_err(dev, "could not disable vref regulator.\n"); > +} > + > +static int max1241_probe(struct spi_device *spi) > +{ > + struct device *dev = &spi->dev; > + struct iio_dev *indio_dev; > + struct max1241 *adc; > + int ret; > + > + indio_dev = devm_iio_device_alloc(dev, sizeof(*adc)); > + if (!indio_dev) > + return -ENOMEM; > + > + adc = iio_priv(indio_dev); > + adc->spi = spi; > + mutex_init(&adc->lock); > + > + spi_set_drvdata(spi, indio_dev); > + > + adc->vdd = devm_regulator_get(dev, "vdd"); > + if (IS_ERR(adc->vdd)) { > + dev_err(dev, "failed to get vdd regulator\n"); > + return PTR_ERR(adc->vdd); > + } > + > + ret = regulator_enable(adc->vdd); > + if (ret) > + return ret; > + > + ret = devm_add_action_or_reset(dev, max1241_disable_vdd_action, adc); > + if (ret) { > + dev_err(dev, "could not set up vdd regulator cleanup action\n"); > + return ret; > + } > + > + adc->vref = devm_regulator_get(dev, "vref"); > + if (IS_ERR(adc->vref)) { > + dev_err(dev, "failed to get vref regulator\n"); > + return PTR_ERR(adc->vref); > + } > + > + ret = regulator_enable(adc->vref); > + if (ret) > + return ret; > + > + ret = devm_add_action_or_reset(dev, max1241_disable_vref_action, adc); > + if (ret) { > + dev_err(dev, "could not set up vref regulator cleanup action\n"); > + return ret; > + } > + > + adc->shutdown = devm_gpiod_get_optional(dev, "shutdown", > + GPIOD_OUT_HIGH); > + if (IS_ERR(adc->shutdown)) > + return PTR_ERR(adc->shutdown); > + > + if (adc->shutdown) > + dev_dbg(dev, "shutdown pin passed, low-power mode enabled"); > + else > + dev_dbg(dev, "no shutdown pin passed, low-power mode disabled"); > + > + indio_dev->name = spi_get_device_id(spi)->name; > + indio_dev->dev.parent = dev; > + indio_dev->info = &max1241_info; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = max1241_channels; > + indio_dev->num_channels = ARRAY_SIZE(max1241_channels); > + > + return devm_iio_device_register(dev, indio_dev); > +} > + > +static const struct spi_device_id max1241_id[] = { > + { "max1241", max1241 }, > + {} > +}; > + > +static const struct of_device_id max1241_dt_ids[] = { > + { .compatible = "maxim,max1241" }, > + {} > +}; > +MODULE_DEVICE_TABLE(of, max1241_dt_ids); > + > +static struct spi_driver max1241_spi_driver = { > + .driver = { > + .name = "max1241", > + .of_match_table = max1241_dt_ids, > + }, > + .probe = max1241_probe, > + .id_table = max1241_id, > +}; > +module_spi_driver(max1241_spi_driver); > + > +MODULE_AUTHOR("Alexandru Lazar <alazar@startmail.com>"); > +MODULE_DESCRIPTION("MAX1241 ADC driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.20.1 > -- With Best Regards, Andy Shevchenko ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v7 2/2] iio: adc: Add MAX1241 driver 2020-04-03 14:20 ` Andy Shevchenko @ 2020-04-03 16:21 ` Alexandru Lazar 2020-04-04 17:02 ` Jonathan Cameron 0 siblings, 1 reply; 9+ messages in thread From: Alexandru Lazar @ 2020-04-03 16:21 UTC (permalink / raw) To: Andy Shevchenko Cc: linux-iio, devicetree, Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen, Peter Meerwald, Rob Herring, Mark Rutland, Alexandru Ardelean > FWIW, > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Thanks! > > Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf > > > No blank line, but this can be fixed by maintainer, I think. Oops! Not sure how I (and checkpatch.pl?) missed that! It's tiny enough to fix inline I guess, but it's not a problem to make a v8 with it if needed. Thanks, Alex ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v7 2/2] iio: adc: Add MAX1241 driver 2020-04-03 16:21 ` Alexandru Lazar @ 2020-04-04 17:02 ` Jonathan Cameron 0 siblings, 0 replies; 9+ messages in thread From: Jonathan Cameron @ 2020-04-04 17:02 UTC (permalink / raw) To: Alexandru Lazar Cc: Andy Shevchenko, linux-iio, devicetree, Hartmut Knaack, Lars-Peter Clausen, Peter Meerwald, Rob Herring, Mark Rutland, Alexandru Ardelean On Fri, 3 Apr 2020 19:21:54 +0300 Alexandru Lazar <alazar@startmail.com> wrote: > > FWIW, > > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > > Thanks! > > > > Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf > > > > > No blank line, but this can be fixed by maintainer, I think. > > Oops! Not sure how I (and checkpatch.pl?) missed that! It's tiny enough > to fix inline I guess, but it's not a problem to make a v8 with it if > needed. > I tidied that up and applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > Thanks, > Alex ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2020-04-14 18:12 UTC | newest] Thread overview: 9+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2020-04-03 12:13 [PATCH v7 0/2] Maxim MAX1241 driver Alexandru Lazar 2020-04-03 12:13 ` [PATCH v7 1/2] dt-bindings: iio: adc: Add MAX1241 bindings Alexandru Lazar 2020-04-04 16:56 ` Jonathan Cameron 2020-04-14 17:45 ` Rob Herring 2020-04-14 18:10 ` Jonathan Cameron 2020-04-03 12:13 ` [PATCH v7 2/2] iio: adc: Add MAX1241 driver Alexandru Lazar 2020-04-03 14:20 ` Andy Shevchenko 2020-04-03 16:21 ` Alexandru Lazar 2020-04-04 17:02 ` Jonathan Cameron
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