Peter, On Wed, Dec 7, 2016 at 1:04 PM, Peter Meerwald-Stadler <pmeerw@xxxxxxxxxx> wrote: > >> Add implementation for Maxim Integrated 5481, 5482, 5483, >> and 5484 digital potentiometer devices. > > nitpicking below Thanks for the review. At this time we aren't in a position to spend time on updates but just wanted to share what we pulled together for others to start from. I'll mark this as rejected. Thanks! > >> Datasheet: >> http://datasheets.maximintegrated.com/en/ds/MAX5481-MAX5484.pdf >> >> Signed-off-by: Maury Anderson <maury.anderson@xxxxxxxxxxxxxxxxxxx> >> Signed-off-by: Matthew Weber <matthew.weber@xxxxxxxxxxxxxxxxxxx> >> --- >> >> This patch is a proposed implementation which compiles and >> is based on the 5487 part. The integration of the component >> was cancelled but we wanted to still share this work hoping >> that others might pick it up. >> >> --- >> .../bindings/iio/potentiometer/max5481.txt | 23 +++ >> drivers/iio/potentiometer/Kconfig | 12 ++ >> drivers/iio/potentiometer/Makefile | 1 + >> drivers/iio/potentiometer/max5481.c | 212 +++++++++++++++++++++ >> 4 files changed, 248 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/iio/potentiometer/max5481.txt >> create mode 100644 drivers/iio/potentiometer/max5481.c >> >> diff --git a/Documentation/devicetree/bindings/iio/potentiometer/max5481.txt b/Documentation/devicetree/bindings/iio/potentiometer/max5481.txt >> new file mode 100644 >> index 0000000..3bc59b4 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/iio/potentiometer/max5481.txt >> @@ -0,0 +1,23 @@ >> +* Maxim Linear-Taper Digital Potentiometer MAX5481-MAX5484 >> + >> +The node for this driver must be a child node of a SPI controller, hence >> +all mandatory properties described in >> + >> + Documentation/devicetree/bindings/spi/spi-bus.txt >> + >> +must be specified. >> + >> +Required properties: >> + - compatible: Must be one of the following, depending on the >> + model: >> + "maxim,max5481" >> + "maxim,max5482" >> + "maxim,max5483" >> + "maxim,max5484" >> + >> +Example: >> +max548x: max548x@0 { >> + compatible = "maxim,max5482"; >> + spi-max-frequency = <7000000``>; > > there are two backticks ``? > >> + reg = <0>; /* chip-select */ >> +}; >> diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig >> index 2e9da1c..872b25b 100644 >> --- a/drivers/iio/potentiometer/Kconfig >> +++ b/drivers/iio/potentiometer/Kconfig >> @@ -15,6 +15,18 @@ config DS1803 >> To compile this driver as a module, choose M here: the >> module will be called ds1803. >> >> +config MAX5481 >> + tristate "Maxim MAX5481-MAX5484 Digital Potentiometer driver" >> + depends on SPI >> + help >> + Say yes here to build support for the Maxim >> + MAX5481, MAX5482, MAX5483, MAX5484 digital potentiometer >> + chips. >> + >> + To compile this driver as a module, choose M here: the >> + module will be called max5481. >> + >> +c > > there is an extra 'c' > >> config MAX5487 >> tristate "Maxim MAX5487/MAX5488/MAX5489 Digital Potentiometer driver" >> depends on SPI >> diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile >> index 8adb58f..2260d40 100644 >> --- a/drivers/iio/potentiometer/Makefile >> +++ b/drivers/iio/potentiometer/Makefile >> @@ -4,6 +4,7 @@ >> >> # When adding new entries keep the list in alphabetical order >> obj-$(CONFIG_DS1803) += ds1803.o >> +obj-$(CONFIG_MAX5481) += max5481.o >> obj-$(CONFIG_MAX5487) += max5487.o >> obj-$(CONFIG_MCP4131) += mcp4131.o >> obj-$(CONFIG_MCP4531) += mcp4531.o >> diff --git a/drivers/iio/potentiometer/max5481.c b/drivers/iio/potentiometer/max5481.c >> new file mode 100644 >> index 0000000..f3feefc >> --- /dev/null >> +++ b/drivers/iio/potentiometer/max5481.c >> @@ -0,0 +1,212 @@ >> +/* >> + * Maxim Integrated MAX5481-MAX5484 digital potentiometer driver >> + * Copyright 2016 Rockwell Collins >> + * >> + * Datasheet: >> + * http://datasheets.maximintegrated.com/en/ds/MAX5481-MAX5484.pdf >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the gnu general public license version 2 as >> + * published by the free software foundation. >> + * >> + */ >> + >> +#include <linux/module.h> >> +#include <linux/spi/spi.h> >> +#include <linux/of.h> >> +#include <linux/acpi.h> >> + >> +#include <linux/iio/sysfs.h> >> +#include <linux/iio/iio.h> >> + >> +/* write wiper reg */ >> +#define MAX5481_WRITE_WIPER (0 << 4) >> +/* copy wiper reg to NV reg */ >> +#define MAX5481_COPY_AB_TO_NV (2 << 4) >> +/* copy NV reg to wiper reg */ >> +#define MAX5481_COPY_NV_TO_AB (3 << 4) >> + >> +#define MAX5481_MAX_POS 1023 >> + >> +enum max5481_variant { >> + max5481, >> + max5482, >> + max5483, >> + max5484 > > add , on the last line, chances are the list will be extended... > >> +}; >> + >> +struct max5481_cfg { >> + int kohms; >> + int maxpos; >> +}; >> + >> +static const struct max5481_cfg max5481_cfg[] = { >> + [max5481] = { .kohms = 10, .maxpos = MAX5481_MAX_POS }, >> + [max5482] = { .kohms = 50, .maxpos = MAX5481_MAX_POS }, >> + [max5483] = { .kohms = 10, .maxpos = MAX5481_MAX_POS }, >> + [max5484] = { .kohms = 50, .maxpos = MAX5481_MAX_POS }, >> +}; > > what is the difference between parts? > >> + >> +struct max5481_data { >> + struct spi_device *spi; >> + const struct max5481_cfg *cfg; >> +}; >> + >> +#define max5481_CHANNEL(ch) { \ > > MAX5481_CHANNEL > is the ch parameter needed? > >> + .type = IIO_RESISTANCE, \ >> + .indexed = 1, \ >> + .output = 1, \ >> + .channel = (ch), \ >> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ >> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ >> +} >> + >> +static const struct iio_chan_spec max5481_channels[] = { >> + max5481_CHANNEL(0), >> +}; >> + >> +static int max5481_write_cmd(struct spi_device *spi, int cmd, int val) >> +{ >> + /* SPI Format from MAX5481-MAX5484 (19-3708; Rev 5; 4/10) pg 15 */ >> + u8 msg[3] = { >> + (u8)cmd, > > cast (u8) needed? > >> + (u8)((u16)val >> 2), >> + (u8)(val & 0x3) << 6 >> + }; >> + >> + return spi_write(spi, msg, (cmd == MAX5481_WRITE_WIPER) ? sizeof(msg) : sizeof(u8)); >> +} >> + >> +static int max5481_read_raw(struct iio_dev *indio_dev, >> + struct iio_chan_spec const *chan, >> + int *val, int *val2, long mask) >> +{ >> + struct max5481_data *data = iio_priv(indio_dev); >> + >> + if (mask != IIO_CHAN_INFO_SCALE) >> + return -EINVAL; >> + >> + *val = 1000 * data->cfg->kohms; >> + *val2 = data->cfg->maxpos; >> + >> + return IIO_VAL_FRACTIONAL; >> +} >> + >> +static int max5481_write_raw(struct iio_dev *indio_dev, >> + struct iio_chan_spec const *chan, >> + int val, int val2, long mask) >> +{ >> + struct max5481_data *data = iio_priv(indio_dev); >> + >> + if (mask != IIO_CHAN_INFO_RAW) >> + return -EINVAL; >> + >> + if (val < 0 || val > data->cfg->maxpos) >> + return -EINVAL; >> + >> + return max5481_write_cmd(data->spi, MAX5481_WRITE_WIPER, val); >> +} >> + >> +static const struct iio_info max5481_info = { >> + .read_raw = max5481_read_raw, >> + .write_raw = max5481_write_raw, >> + .driver_module = THIS_MODULE, >> +}; >> + >> +static int max5481_probe(struct spi_device *spi) >> +{ >> + struct iio_dev *indio_dev; >> + struct max5481_data *data; >> + const struct spi_device_id *id = spi_get_device_id(spi); >> + int ret; >> + >> + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data)); >> + if (!indio_dev) >> + return -ENOMEM; >> + >> + dev_set_drvdata(&spi->dev, indio_dev); >> + data = iio_priv(indio_dev); >> + >> + data->spi = spi; >> + data->cfg = &max5481_cfg[id->driver_data]; >> + >> + indio_dev->name = id->name; >> + indio_dev->dev.parent = &spi->dev; >> + indio_dev->modes = INDIO_DIRECT_MODE; >> + >> + /* variant specific configuration */ >> + indio_dev->info = &max5481_info; >> + indio_dev->channels = max5481_channels; >> + indio_dev->num_channels = ARRAY_SIZE(max5481_channels); >> + >> + /* restore wiper from NV */ >> + ret = max5481_write_cmd(data->spi, MAX5481_COPY_NV_TO_AB, 0); >> + if (ret < 0) >> + return ret; >> + >> + return iio_device_register(indio_dev); >> +} >> + >> +static int max5481_remove(struct spi_device *spi) >> +{ >> + struct iio_dev *indio_dev = dev_get_drvdata(&spi->dev); >> + int ret; >> + >> + /* save wiper reg to NV reg */ >> + ret = max5481_write_cmd(spi, MAX5481_COPY_AB_TO_NV, 0); >> + >> + iio_device_unregister(indio_dev); > > unregister first, then save > >> + >> + return ret; >> +} >> + >> +static const struct spi_device_id max5481_id_table[] = { >> + { "MAX5481", max5481 }, >> + { "MAX5482", max5482 }, >> + { "MAX5483", max5483 }, >> + { "MAX5484", max5484 }, >> + { } >> +}; >> +MODULE_DEVICE_TABLE(spi, max5481_id_table); >> + >> +#if defined(CONFIG_OF) >> +static const struct of_device_id max5481_match[] = { >> + { .compatible = "maxim,max5481", .data = &max5481_cfg[max5481] }, >> + { .compatible = "maxim,max5482", .data = &max5481_cfg[max5482] }, >> + { .compatible = "maxim,max5483", .data = &max5481_cfg[max5483] }, >> + { .compatible = "maxim,max5484", .data = &max5481_cfg[max5484] }, >> + { } >> +}; >> +MODULE_DEVICE_TABLE(of, max5481_match); >> +#endif >> + >> +#if defined(CONFIG_ACPI) >> +static const struct acpi_device_id max5481_acpi_match[] = { >> + { "MAX5481", max5481 }, >> + { "MAX5482", max5482 }, >> + { "MAX5483", max5483 }, >> + { "MAX5484", max5484 }, >> + { } >> +}; >> +MODULE_DEVICE_TABLE(acpi, max5481_acpi_match); >> +#endif >> + >> +static struct spi_driver max5481_driver = >> +{ >> + .driver = >> + { >> + .name = "max5481", >> + .owner = THIS_MODULE, >> + .of_match_table = of_match_ptr(max5481_match), >> + .acpi_match_table = ACPI_PTR(max5481_acpi_match), >> + }, >> + .probe = max5481_probe, >> + .remove = max5481_remove, >> + .id_table = max5481_id_table, >> +}; >> + >> +module_spi_driver(max5481_driver); >> + >> +MODULE_AUTHOR("Maury Anderson <maury.anderson@xxxxxxxxxxxxxxxxxxx>"); >> +MODULE_DESCRIPTION("max5481 SPI driver"); >> +MODULE_LICENSE("GPL v2"); >> > > -- > > Peter Meerwald-Stadler > +43-664-2444418 (mobile) -- Matthew L Weber / Pr Software Engineer Airborne Information Systems / Security Systems and Software / Secure Platforms MS 131-100, C Ave NE, Cedar Rapids, IA, 52498, USA www.rockwellcollins.com Note: Any Export License Required Information and License Restricted Third Party Intellectual Property (TPIP) content must be encrypted and sent to matthew.weber@xxxxxxxxxxxxxxxxxxxxxxxx. -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
