On 13/10/15 10:46, Sean Nyekjær wrote: > Hi > > I'm having a problems with the ads8688_write_raw_get_fmt function. > > Firstly the OFFSET and the SCALE its switched around. Ill fix that :-) > Secondly the i'm not allowed to return IIO_VAL_INT, this results in the > iio_write_channel_info() is returning -EINVAL. The iio_write_channel_info() only checks if the write_raw_get_fmt is existing... > Do I need to convert the OFFSET to a IIO_VAL_INT_PLUS_NANO aswell or ? Nope. The core needs extending to actually support IIO_VAL_INT. Though cynically setting it to IIO_VAL_INT_PLUS_MICRO and checking the val2 is 0 would work as well if you want a quick solution. Adding IIO_VAL_INT support should be fairly straightforward, though I'd bypass the string to fixedpoint convertor in this case and do it with an scanf. > > /Sean > > On 2015-10-11 16:53, Jonathan Cameron wrote: >> On 06/10/15 09:12, Sean Nyekjaer wrote: >>> This patch adds support for the Texas Intruments ADS8688 ADC. >>> >>> Signed-off-by: Sean Nyekjaer <sean.nyekjaer@xxxxxxxxx> >>> Reviewed-by: Martin Hundebøll <martin.hundeboll@xxxxxxxxx> >> only one issue that I can see. You do need locking to protect >> your local buffers. A local lock in the same structure would be >> appropriate for this. >> >> Neither sysfs nor IIO provide any serialization guarantees >> so multiple concurrent reads are more than possible and may >> cause you data corruption as it stands. >> >> Other than that, it's looking very nice. >> >> Thanks, >> >> Jonathan >>> --- >>> Changes since v3: >>> - fixed multiline comments >>> - write_raw_get_fmt _SCALE is nano, _OFFSET is int >>> >>> Changes since v2: >>> - Removed unused variables >>> - Removed unnecessary mutex lock >>> - Range array is a enum >>> - Made the read and write functions less complex and easier to read >>> - Added inline comments >>> - Added callback to write_raw_get_fmt >>> >>> Changes since v1: >>> - Now possible to read and write the actual offset and scale values >>> - Removed unused includes >>> - Removed unused buffer references >>> drivers/iio/adc/Kconfig | 10 + >>> drivers/iio/adc/Makefile | 1 + >>> drivers/iio/adc/ti-ads8688.c | 472 +++++++++++++++++++++++++++++++++++++++++++ >>> 3 files changed, 483 insertions(+) >>> create mode 100644 drivers/iio/adc/ti-ads8688.c >>> >>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig >>> index 7868c74..4135d17 100644 >>> --- a/drivers/iio/adc/Kconfig >>> +++ b/drivers/iio/adc/Kconfig >>> @@ -333,6 +333,16 @@ config TI_ADC128S052 >>> This driver can also be built as a module. If so, the module will be >>> called ti-adc128s052. >>> +config TI_ADS8688 >>> + tristate "Texas Instruments ADS8688" >>> + depends on SPI && OF >>> + help >>> + If you say yes here you get support for Texas Instruments ADS8684 and >>> + and ADS8688 ADC chips >>> + >>> + This driver can also be built as a module. If so, the module will be >>> + called ti-ads8688. >>> + >>> config TI_AM335X_ADC >>> tristate "TI's AM335X ADC driver" >>> depends on MFD_TI_AM335X_TSCADC >>> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile >>> index 99b37a9..04ab2c8 100644 >>> --- a/drivers/iio/adc/Makefile >>> +++ b/drivers/iio/adc/Makefile >>> @@ -32,6 +32,7 @@ obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o >>> obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o >>> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o >>> obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o >>> +obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o >>> obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o >>> obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o >>> obj-$(CONFIG_TWL6030_GPADC) += twl6030-gpadc.o >>> diff --git a/drivers/iio/adc/ti-ads8688.c b/drivers/iio/adc/ti-ads8688.c >>> new file mode 100644 >>> index 0000000..537bb0a >>> --- /dev/null >>> +++ b/drivers/iio/adc/ti-ads8688.c >>> @@ -0,0 +1,472 @@ >>> +/* >>> + * Copyright (C) 2015 Prevas A/S >>> + * >>> + * 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/device.h> >>> +#include <linux/kernel.h> >>> +#include <linux/slab.h> >>> +#include <linux/sysfs.h> >>> +#include <linux/spi/spi.h> >>> +#include <linux/regulator/consumer.h> >>> +#include <linux/err.h> >>> +#include <linux/module.h> >>> +#include <linux/of.h> >>> + >>> +#include <linux/iio/iio.h> >>> +#include <linux/iio/sysfs.h> >>> + >>> +#define ADS8688_CMD_REG(x) (x << 8) >>> +#define ADS8688_CMD_REG_NOOP 0x00 >>> +#define ADS8688_CMD_REG_RST 0x85 >>> +#define ADS8688_CMD_REG_MAN_CH(chan) (0xC0 | (4 * chan)) >>> +#define ADS8688_CMD_DONT_CARE_BITS 16 >>> + >>> +#define ADS8688_PROG_REG(x) (x << 9) >>> +#define ADS8688_PROG_REG_RANGE_CH(chan) (0x05 + chan) >>> +#define ADS8688_PROG_WR_BIT BIT(8) >>> +#define ADS8688_PROG_DONT_CARE_BITS 8 >>> + >>> +#define ADS8688_REG_PLUSMINUS25VREF 0 >>> +#define ADS8688_REG_PLUSMINUS125VREF 1 >>> +#define ADS8688_REG_PLUSMINUS0625VREF 2 >>> +#define ADS8688_REG_PLUS25VREF 5 >>> +#define ADS8688_REG_PLUS125VREF 6 >>> + >>> +#define ADS8688_VREF_MV 4096 >>> +#define ADS8688_REALBITS 16 >>> + >>> +/* >>> + * enum ads8688_range - ADS8688 reference voltage range >>> + * @ADS8688_PLUSMINUS25VREF: Device is configured for input range ±2.5 * VREF >>> + * @ADS8688_PLUSMINUS125VREF: Device is configured for input range ±1.25 * VREF >>> + * @ADS8688_PLUSMINUS0625VREF: Device is configured for input range ±0.625 * VREF >>> + * @ADS8688_PLUS25VREF: Device is configured for input range 0 - 2.5 * VREF >>> + * @ADS8688_PLUS125VREF: Device is configured for input range 0 - 1.25 * VREF >>> + */ >>> +enum ads8688_range { >>> + ADS8688_PLUSMINUS25VREF, >>> + ADS8688_PLUSMINUS125VREF, >>> + ADS8688_PLUSMINUS0625VREF, >>> + ADS8688_PLUS25VREF, >>> + ADS8688_PLUS125VREF, >>> +}; >>> + >>> +struct ads8688_chip_info { >>> + const struct iio_chan_spec *channels; >>> + unsigned int num_channels; >>> +}; >>> + >>> +struct ads8688_state { >>> + const struct ads8688_chip_info *chip_info; >>> + struct spi_device *spi; >>> + struct regulator *reg; >>> + unsigned int vref_mv; >>> + enum ads8688_range range[8]; >> Oops, missed this before. You need to have locking around >> your databuffer. There is nothing in sysfs or the IIO >> core to prevent multiple concurrent reads.. >> >> I note you mention removing an unecessary lock. I think that >> was a missunderstanding. Locking is necessary, just not >> using the IIO mutex that exists to protect against state >> change issues (enabling buffers for example). >> >> So there should be a local lock to protect this next element. >> >>> + union { >>> + __be32 d32; >>> + u8 d8[4]; >>> + } data[2] ____cacheline_aligned; >>> +}; >>> + >>> +enum ads8688_id { >>> + ID_ADS8684, >>> + ID_ADS8688, >>> +}; >>> + >>> +struct ads8688_ranges { >>> + enum ads8688_range range; >>> + unsigned int scale; >>> + int offset; >>> + u8 reg; >>> +}; >>> + >>> +static const struct ads8688_ranges ads8688_range_def[5] = { >>> + { >>> + .range = ADS8688_PLUSMINUS25VREF, >>> + .scale = 76295, >>> + .offset = -(1 << (ADS8688_REALBITS - 1)), >>> + .reg = ADS8688_REG_PLUSMINUS25VREF, >>> + }, { >>> + .range = ADS8688_PLUSMINUS125VREF, >>> + .scale = 38148, >>> + .offset = -(1 << (ADS8688_REALBITS - 1)), >>> + .reg = ADS8688_REG_PLUSMINUS125VREF, >>> + }, { >>> + .range = ADS8688_PLUSMINUS0625VREF, >>> + .scale = 19074, >>> + .offset = -(1 << (ADS8688_REALBITS - 1)), >>> + .reg = ADS8688_REG_PLUSMINUS0625VREF, >>> + }, { >>> + .range = ADS8688_PLUS25VREF, >>> + .scale = 38148, >>> + .offset = 0, >>> + .reg = ADS8688_REG_PLUS25VREF, >>> + }, { >>> + .range = ADS8688_PLUS125VREF, >>> + .scale = 19074, >>> + .offset = 0, >>> + .reg = ADS8688_REG_PLUS125VREF, >>> + } >>> +}; >>> + >>> +static ssize_t ads8688_show_scales(struct device *dev, >>> + struct device_attribute *attr, char *buf) >>> +{ >>> + struct ads8688_state *st = iio_priv(dev_to_iio_dev(dev)); >>> + >>> + return sprintf(buf, "0.%09u 0.%09u 0.%09u\n", >>> + ads8688_range_def[0].scale * st->vref_mv, >>> + ads8688_range_def[1].scale * st->vref_mv, >>> + ads8688_range_def[2].scale * st->vref_mv); >>> +} >>> + >>> +static ssize_t ads8688_show_offsets(struct device *dev, >>> + struct device_attribute *attr, char *buf) >>> +{ >>> + return sprintf(buf, "%d %d\n", ads8688_range_def[0].offset, >>> + ads8688_range_def[3].offset); >>> +} >>> + >>> +static IIO_DEVICE_ATTR(in_voltage_scale_available, S_IRUGO, >>> + ads8688_show_scales, NULL, 0); >>> +static IIO_DEVICE_ATTR(in_voltage_offset_available, S_IRUGO, >>> + ads8688_show_offsets, NULL, 0); >>> + >>> +static struct attribute *ads8688_attributes[] = { >>> + &iio_dev_attr_in_voltage_scale_available.dev_attr.attr, >>> + &iio_dev_attr_in_voltage_offset_available.dev_attr.attr, >>> + NULL, >>> +}; >>> + >>> +static const struct attribute_group ads8688_attribute_group = { >>> + .attrs = ads8688_attributes, >>> +}; >>> + >>> +#define ADS8688_CHAN(index) \ >>> +{ \ >>> + .type = IIO_VOLTAGE, \ >>> + .indexed = 1, \ >>> + .channel = index, \ >>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \ >>> + | BIT(IIO_CHAN_INFO_SCALE) \ >>> + | BIT(IIO_CHAN_INFO_OFFSET), \ >>> +} >>> + >>> +static const struct iio_chan_spec ads8684_channels[] = { >>> + ADS8688_CHAN(0), >>> + ADS8688_CHAN(1), >>> + ADS8688_CHAN(2), >>> + ADS8688_CHAN(3), >>> +}; >>> + >>> +static const struct iio_chan_spec ads8688_channels[] = { >>> + ADS8688_CHAN(0), >>> + ADS8688_CHAN(1), >>> + ADS8688_CHAN(2), >>> + ADS8688_CHAN(3), >>> + ADS8688_CHAN(4), >>> + ADS8688_CHAN(5), >>> + ADS8688_CHAN(6), >>> + ADS8688_CHAN(7), >>> +}; >>> + >>> +static int ads8688_prog_write(struct iio_dev *indio_dev, unsigned int addr, >>> + unsigned int val) >>> +{ >>> + struct ads8688_state *st = iio_priv(indio_dev); >>> + u32 tmp; >>> + >>> + tmp = ADS8688_PROG_REG(addr) | ADS8688_PROG_WR_BIT | val; >>> + tmp <<= ADS8688_PROG_DONT_CARE_BITS; >>> + st->data[0].d32 = cpu_to_be32(tmp); >>> + >>> + return spi_write(st->spi, &st->data[0].d8[1], 3); >>> +} >>> + >>> +static int ads8688_reset(struct iio_dev *indio_dev) >>> +{ >>> + struct ads8688_state *st = iio_priv(indio_dev); >>> + u32 tmp; >>> + >>> + tmp = ADS8688_CMD_REG(ADS8688_CMD_REG_RST); >>> + tmp <<= ADS8688_CMD_DONT_CARE_BITS; >>> + st->data[0].d32 = cpu_to_be32(tmp); >>> + >>> + return spi_write(st->spi, &st->data[0].d8[0], 4); >>> +} >>> + >>> +static int ads8688_read(struct iio_dev *indio_dev, unsigned int chan) >>> +{ >>> + struct ads8688_state *st = iio_priv(indio_dev); >>> + int ret; >>> + u32 tmp; >>> + struct spi_transfer t[] = { >>> + { >>> + .tx_buf = &st->data[0].d8[0], >>> + .len = 4, >>> + .cs_change = 1, >>> + }, { >>> + .tx_buf = &st->data[1].d8[0], >>> + .rx_buf = &st->data[1].d8[0], >>> + .len = 4, >>> + }, >>> + }; >>> + >>> + tmp = ADS8688_CMD_REG(ADS8688_CMD_REG_MAN_CH(chan)); >>> + tmp <<= ADS8688_CMD_DONT_CARE_BITS; >>> + st->data[0].d32 = cpu_to_be32(tmp); >>> + >>> + tmp = ADS8688_CMD_REG(ADS8688_CMD_REG_NOOP); >>> + tmp <<= ADS8688_CMD_DONT_CARE_BITS; >>> + st->data[1].d32 = cpu_to_be32(tmp); >>> + >>> + ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t)); >>> + if (ret < 0) >>> + return ret; >>> + >>> + return be32_to_cpu(st->data[1].d32) & 0xffff; >>> +} >>> + >>> +static int ads8688_read_raw(struct iio_dev *indio_dev, >>> + struct iio_chan_spec const *chan, >>> + int *val, int *val2, long m) >>> +{ >>> + int ret, offset; >>> + unsigned long scale_mv; >>> + >>> + struct ads8688_state *st = iio_priv(indio_dev); >>> + >>> + switch (m) { >>> + case IIO_CHAN_INFO_RAW: >>> + ret = ads8688_read(indio_dev, chan->channel); >>> + if (ret < 0) >>> + return ret; >>> + *val = ret; >>> + return IIO_VAL_INT; >>> + case IIO_CHAN_INFO_SCALE: >>> + scale_mv = st->vref_mv; >>> + scale_mv *= ads8688_range_def[st->range[chan->channel]].scale; >>> + *val = 0; >>> + *val2 = scale_mv; >>> + return IIO_VAL_INT_PLUS_NANO; >>> + case IIO_CHAN_INFO_OFFSET: >>> + offset = ads8688_range_def[st->range[chan->channel]].offset; >>> + *val = offset; >>> + return IIO_VAL_INT; >>> + } >>> + >>> + return -EINVAL; >>> +} >>> + >>> +static int ads8688_write_reg_range(struct iio_dev *indio_dev, >>> + struct iio_chan_spec const *chan, >>> + enum ads8688_range range) >>> +{ >>> + unsigned int tmp; >>> + int ret; >>> + >>> + tmp = ADS8688_PROG_REG_RANGE_CH(chan->channel); >>> + ret = ads8688_prog_write(indio_dev, tmp, range); >>> + >>> + return ret; >>> +} >>> + >>> +static int ads8688_write_raw(struct iio_dev *indio_dev, >>> + struct iio_chan_spec const *chan, >>> + int val, int val2, long mask) >>> +{ >>> + struct ads8688_state *st = iio_priv(indio_dev); >>> + unsigned int scale = 0; >>> + int ret = -EINVAL, i, offset = 0; >>> + >>> + switch (mask) { >>> + case IIO_CHAN_INFO_SCALE: >>> + /* If the offset is 0 the ±2.5 * VREF mode is not available */ >>> + offset = ads8688_range_def[st->range[chan->channel]].offset; >>> + if (offset == 0 && val2 == ads8688_range_def[0].scale * st->vref_mv) >>> + return -EINVAL; >>> + >>> + /* Lookup new mode */ >>> + for (i = 0; i < ARRAY_SIZE(ads8688_range_def); i++) >>> + if (val2 == ads8688_range_def[i].scale * st->vref_mv && >>> + offset == ads8688_range_def[i].offset) { >>> + ret = ads8688_write_reg_range(indio_dev, chan, >>> + ads8688_range_def[i].reg); >>> + break; >>> + } >>> + break; >>> + case IIO_CHAN_INFO_OFFSET: >>> + /* >>> + * There are only two available offsets: >>> + * 0 and -(1 << (ADS8688_REALBITS - 1)) >>> + */ >>> + if (!(ads8688_range_def[0].offset == val || >>> + ads8688_range_def[3].offset == val)) >>> + return -EINVAL; >>> + >>> + /* >>> + * If the device are in ±2.5 * VREF mode, it's not allowed to >>> + * switch to a mode where the offset is 0 >>> + */ >>> + if (0 == val && >>> + st->range[chan->channel] == ADS8688_PLUSMINUS25VREF) >>> + return -EINVAL; >>> + >>> + scale = ads8688_range_def[st->range[chan->channel]].scale; >>> + >>> + /* Lookup new mode */ >>> + for (i = 0; i < ARRAY_SIZE(ads8688_range_def); i++) >>> + if (val == ads8688_range_def[i].offset && >>> + scale == ads8688_range_def[i].scale) { >>> + ret = ads8688_write_reg_range(indio_dev, chan, >>> + ads8688_range_def[i].reg); >>> + break; >>> + } >>> + break; >>> + } >>> + >>> + if (!ret) >>> + st->range[chan->channel] = ads8688_range_def[i].range; >>> + >>> + return ret; >>> +} >>> + >>> +static int ads8688_write_raw_get_fmt(struct iio_dev *indio_dev, >>> + struct iio_chan_spec const *chan, >>> + long mask) >>> +{ >>> + switch (mask) { >>> + case IIO_CHAN_INFO_SCALE: >>> + return IIO_VAL_INT; >>> + case IIO_CHAN_INFO_OFFSET: >>> + return IIO_VAL_INT_PLUS_NANO; >>> + } >>> + >>> + return -EINVAL; >>> +} >>> + >>> +static const struct iio_info ads8688_info = { >>> + .read_raw = &ads8688_read_raw, >>> + .write_raw = &ads8688_write_raw, >>> + .write_raw_get_fmt = &ads8688_write_raw_get_fmt, >>> + .attrs = &ads8688_attribute_group, >>> + .driver_module = THIS_MODULE, >>> +}; >>> + >>> +static const struct ads8688_chip_info ads8688_chip_info_tbl[] = { >>> + [ID_ADS8684] = { >>> + .channels = ads8684_channels, >>> + .num_channels = ARRAY_SIZE(ads8684_channels), >>> + }, >>> + [ID_ADS8688] = { >>> + .channels = ads8688_channels, >>> + .num_channels = ARRAY_SIZE(ads8688_channels), >>> + }, >>> +}; >>> + >>> +static int ads8688_probe(struct spi_device *spi) >>> +{ >>> + struct ads8688_state *st; >>> + struct iio_dev *indio_dev; >>> + int ret; >>> + >>> + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); >>> + if (indio_dev == NULL) >>> + return -ENOMEM; >>> + >>> + st = iio_priv(indio_dev); >>> + >>> + if (spi->dev.of_node && of_property_read_bool(spi->dev.of_node, >>> + "vref-supply")) { >>> + st->reg = devm_regulator_get(&spi->dev, "vref"); >>> + if (!IS_ERR(st->reg)) { >>> + ret = regulator_enable(st->reg); >>> + if (ret) >>> + return ret; >>> + >>> + ret = regulator_get_voltage(st->reg); >>> + if (ret < 0) >>> + goto error_out; >>> + >>> + st->vref_mv = ret / 1000; >>> + } >>> + } else { >>> + /* Use internal reference */ >>> + st->vref_mv = ADS8688_VREF_MV; >>> + } >>> + >>> + st->chip_info = &ads8688_chip_info_tbl[spi_get_device_id(spi)->driver_data]; >>> + >>> + spi->mode = SPI_MODE_1; >>> + >>> + spi_set_drvdata(spi, indio_dev); >>> + >>> + st->spi = spi; >>> + >>> + indio_dev->name = spi_get_device_id(spi)->name; >>> + indio_dev->dev.parent = &spi->dev; >>> + indio_dev->modes = INDIO_DIRECT_MODE; >>> + indio_dev->channels = st->chip_info->channels; >>> + indio_dev->num_channels = st->chip_info->num_channels; >>> + indio_dev->info = &ads8688_info; >>> + >>> + ads8688_reset(indio_dev); >>> + >>> + ret = iio_device_register(indio_dev); >>> + if (ret) >>> + goto error_out; >>> + >>> + return 0; >>> + >>> +error_out: >>> + if (!IS_ERR_OR_NULL(st->reg)) >>> + regulator_disable(st->reg); >>> + >>> + return ret; >>> +} >>> + >>> +static int ads8688_remove(struct spi_device *spi) >>> +{ >>> + struct iio_dev *indio_dev = spi_get_drvdata(spi); >>> + struct ads8688_state *st = iio_priv(indio_dev); >>> + >>> + iio_device_unregister(indio_dev); >>> + >>> + if (!IS_ERR_OR_NULL(st->reg)) >>> + regulator_disable(st->reg); >>> + >>> + return 0; >>> +} >>> + >>> +static const struct spi_device_id ads8688_id[] = { >>> + {"ads8684", ID_ADS8684}, >>> + {"ads8688", ID_ADS8688}, >>> + {} >>> +}; >>> +MODULE_DEVICE_TABLE(spi, ads8688_id); >>> + >>> +static const struct of_device_id ads8688_of_match[] = { >>> + { .compatible = "ti,ads8684" }, >>> + { .compatible = "ti,ads8688" }, >>> + { } >>> +}; >>> +MODULE_DEVICE_TABLE(of, ads8688_of_match); >>> + >>> +static struct spi_driver ads8688_driver = { >>> + .driver = { >>> + .name = "ads8688", >>> + .owner = THIS_MODULE, >>> + }, >>> + .probe = ads8688_probe, >>> + .remove = ads8688_remove, >>> + .id_table = ads8688_id, >>> +}; >>> +module_spi_driver(ads8688_driver); >>> + >>> +MODULE_AUTHOR("Sean Nyekjaer <sean.nyekjaer@xxxxxxxxx>"); >>> +MODULE_DESCRIPTION("Texas Instruments ADS8688 driver"); >>> +MODULE_LICENSE("GPL v2"); >>> > -- > 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 -- 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