Re: [PATCH v3 2/3] iio: adc: Add the TI ads124s08 ADC code

From: Dan Murphy
Date: Mon Jan 14 2019 - 16:31:39 EST

Jonathan

On 1/12/19 12:43 PM, Jonathan Cameron wrote:
> On Sat, 12 Jan 2019 18:42:49 +0000
> Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
>
>> On Fri, 11 Jan 2019 13:57:06 -0600
>> Dan Murphy <dmurphy@xxxxxx> wrote:
>>
>>> Introduce the TI ADS124S08 and the ADS124S06 ADC
>>> devices from TI. The ADS124S08 is the 12 channel ADC
>>> and the ADS124S06 is the 6 channel ADC device
>>>
>>> These devices share a common datasheet:
>>> http://www.ti.com/lit/gpn/ads124s08
>>>
>>> Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
>> Hi Dan,
>>
>> The only real change in here (there is another nitpick) that I think
>> needs to be made is that the buffer length in the private stucture is
>> not longer connected to the number of channels. You effectively use it
>> as a bounce buffer now and I think the maximum is 5.
>>
>> As that's it I'll just clean it up whilst applying. If you could
>> confirm I'm not crazy and didn't mess it up that would be great!
> Probably would help if I added.
>
> Applied to the togreg branch of iio.git but for now just pushed out
> as testing for the autobuilders to play with it.


Thank you. I assume if there are no issue then this will be in a PR for 5.1 then?

Dan

>
> Thanks,
>
> Jonathan
>
>>
>> Thanks,
>>
>> Jonathan
>>
>>> ---
>>> v3 - Fixed the IIO channel definition, reduce long line in probe and
>>> fixed the buffer allocation definition - https://lore.kernel.org/patchwork/patch/1023970/
>>>
>>> v2 - Removed the fill_noop call, updated probe to use device managed calls,
>>> removed regulator support, fixed the buffer to allow 64 bit timestamp, changed
>>> all the defines from S0X to S08, added an enum for the IDs and updated copyright
>>> header format. I may have missed a few summary changes here but here is the
>>> review reference - https://lore.kernel.org/patchwork/patch/1021048/
>>>
>>> drivers/iio/adc/Kconfig | 10 +
>>> drivers/iio/adc/Makefile | 1 +
>>> drivers/iio/adc/ti-ads124s08.c | 375 +++++++++++++++++++++++++++++++++
>>> 3 files changed, 386 insertions(+)
>>> create mode 100644 drivers/iio/adc/ti-ads124s08.c
>>>
>>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>>> index 7a3ca4ec0cb7..8cf9e007ea76 100644
>>> --- a/drivers/iio/adc/Kconfig
>>> +++ b/drivers/iio/adc/Kconfig
>>> @@ -908,6 +908,16 @@ config TI_ADS8688
>>> This driver can also be built as a module. If so, the module will be
>>> called ti-ads8688.
>>>
>>> +config TI_ADS124S08
>>> + tristate "Texas Instruments ADS124S08"
>>> + depends on SPI && OF
>>> + help
>>> + If you say yes here you get support for Texas Instruments ADS124S08
>>> + and ADS124S06 ADC chips
>>> +
>>> + This driver can also be built as a module. If so, the module will be
>>> + called ti-ads124s08.
>>> +
>>> config TI_AM335X_ADC
>>> tristate "TI's AM335X ADC driver"
>>> depends on MFD_TI_AM335X_TSCADC && HAS_DMA
>>> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
>>> index 07df37f621bd..49b203bf4e0e 100644
>>> --- a/drivers/iio/adc/Makefile
>>> +++ b/drivers/iio/adc/Makefile
>>> @@ -81,6 +81,7 @@ obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o
>>> obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
>>> obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o
>>> obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
>>> +obj-$(CONFIG_TI_ADS124S08) += ti-ads124s08.o
>>> obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
>>> obj-$(CONFIG_TI_TLC4541) += ti-tlc4541.o
>>> obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o
>>> diff --git a/drivers/iio/adc/ti-ads124s08.c b/drivers/iio/adc/ti-ads124s08.c
>>> new file mode 100644
>>> index 000000000000..3d7f2300e0f6
>>> --- /dev/null
>>> +++ b/drivers/iio/adc/ti-ads124s08.c
>>> @@ -0,0 +1,375 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/* TI ADS124S0X chip family driver
>>> + * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
>>> + */
>>> +
>>> +#include <linux/err.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/device.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of.h>
>>> +#include <linux/of_gpio.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/sysfs.h>
>>> +
>>> +#include <linux/gpio/consumer.h>
>>> +#include <linux/spi/spi.h>
>>> +
>>> +#include <linux/iio/iio.h>
>>> +#include <linux/iio/buffer.h>
>>> +#include <linux/iio/trigger_consumer.h>
>>> +#include <linux/iio/triggered_buffer.h>
>>> +#include <linux/iio/sysfs.h>
>>> +
>>> +/* Commands */
>>> +#define ADS124S08_CMD_NOP 0x00
>>> +#define ADS124S08_CMD_WAKEUP 0x02
>>> +#define ADS124S08_CMD_PWRDWN 0x04
>>> +#define ADS124S08_CMD_RESET 0x06
>>> +#define ADS124S08_CMD_START 0x08
>>> +#define ADS124S08_CMD_STOP 0x0a
>>> +#define ADS124S08_CMD_SYOCAL 0x16
>>> +#define ADS124S08_CMD_SYGCAL 0x17
>>> +#define ADS124S08_CMD_SFOCAL 0x19
>>> +#define ADS124S08_CMD_RDATA 0x12
>>> +#define ADS124S08_CMD_RREG 0x20
>>> +#define ADS124S08_CMD_WREG 0x40
>>> +
>>> +/* Registers */
>>> +#define ADS124S08_ID_REG 0x00
>>> +#define ADS124S08_STATUS 0x01
>>> +#define ADS124S08_INPUT_MUX 0x02
>>> +#define ADS124S08_PGA 0x03
>>> +#define ADS124S08_DATA_RATE 0x04
>>> +#define ADS124S08_REF 0x05
>>> +#define ADS124S08_IDACMAG 0x06
>>> +#define ADS124S08_IDACMUX 0x07
>>> +#define ADS124S08_VBIAS 0x08
>>> +#define ADS124S08_SYS 0x09
>>> +#define ADS124S08_OFCAL0 0x0a
>>> +#define ADS124S08_OFCAL1 0x0b
>>> +#define ADS124S08_OFCAL2 0x0c
>>> +#define ADS124S08_FSCAL0 0x0d
>>> +#define ADS124S08_FSCAL1 0x0e
>>> +#define ADS124S08_FSCAL2 0x0f
>>> +#define ADS124S08_GPIODAT 0x10
>>> +#define ADS124S08_GPIOCON 0x11
>>> +
>>> +/* ADS124S0x common channels */
>>> +#define ADS124S08_AIN0 0x00
>>> +#define ADS124S08_AIN1 0x01
>>> +#define ADS124S08_AIN2 0x02
>>> +#define ADS124S08_AIN3 0x03
>>> +#define ADS124S08_AIN4 0x04
>>> +#define ADS124S08_AIN5 0x05
>>> +#define ADS124S08_AINCOM 0x0c
>>> +/* ADS124S08 only channels */
>>> +#define ADS124S08_AIN6 0x06
>>> +#define ADS124S08_AIN7 0x07
>>> +#define ADS124S08_AIN8 0x08
>>> +#define ADS124S08_AIN9 0x09
>>> +#define ADS124S08_AIN10 0x0a
>>> +#define ADS124S08_AIN11 0x0b
>>> +#define ADS124S08_MAX_CHANNELS 12
>>> +
>>> +#define ADS124S08_POS_MUX_SHIFT 0x04
>>> +#define ADS124S08_INT_REF 0x09
>>> +
>>> +#define ADS124S08_START_REG_MASK 0x1f
>>> +#define ADS124S08_NUM_BYTES_MASK 0x1f
>>> +
>>> +#define ADS124S08_START_CONV 0x01
>>> +#define ADS124S08_STOP_CONV 0x00
>>> +
>>> +enum ads124s_id {
>>> + ADS124S08_ID,
>>> + ADS124S06_ID,
>>> +};
>>> +
>>> +struct ads124s_chip_info {
>>> + const struct iio_chan_spec *channels;
>>> + unsigned int num_channels;
>>> +};
>>> +
>>> +struct ads124s_private {
>>> + const struct ads124s_chip_info *chip_info;
>>> + struct gpio_desc *reset_gpio;
>>> + struct spi_device *spi;
>>> + struct mutex lock;
>>> + u8 data[ADS124S08_MAX_CHANNELS] ____cacheline_aligned;
>>
>> I'm fairly sure this only needs to be 5 not MAX_CHANNELS as you use
>> another buffer to build up the full set of readouts.
>>
>>> +};
>>> +
>>> +#define ADS124S08_CHAN(index) \
>>> +{ \
>>> + .type = IIO_VOLTAGE, \
>>> + .indexed = 1, \
>>> + .channel = index, \
>>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>>> + .scan_index = index, \
>>> + .scan_type = { \
>>> + .sign = 'u', \
>>> + .realbits = 32, \
>>> + .storagebits = 32, \
>>> + }, \
>>> +}
>>> +
>>> +static const struct iio_chan_spec ads124s06_channels[] = {
>>> + ADS124S08_CHAN(0),
>>> + ADS124S08_CHAN(1),
>>> + ADS124S08_CHAN(2),
>>> + ADS124S08_CHAN(3),
>>> + ADS124S08_CHAN(4),
>>> + ADS124S08_CHAN(5),
>>> +};
>>> +
>>> +static const struct iio_chan_spec ads124s08_channels[] = {
>>> + ADS124S08_CHAN(0),
>>> + ADS124S08_CHAN(1),
>>> + ADS124S08_CHAN(2),
>>> + ADS124S08_CHAN(3),
>>> + ADS124S08_CHAN(4),
>>> + ADS124S08_CHAN(5),
>>> + ADS124S08_CHAN(6),
>>> + ADS124S08_CHAN(7),
>>> + ADS124S08_CHAN(8),
>>> + ADS124S08_CHAN(9),
>>> + ADS124S08_CHAN(10),
>>> + ADS124S08_CHAN(11),
>>> +};
>>> +
>>> +static const struct ads124s_chip_info ads124s_chip_info_tbl[] = {
>>> + [ADS124S08_ID] = {
>>> + .channels = ads124s08_channels,
>>> + .num_channels = ARRAY_SIZE(ads124s08_channels),
>>> + },
>>> + [ADS124S06_ID] = {
>>> + .channels = ads124s06_channels,
>>> + .num_channels = ARRAY_SIZE(ads124s06_channels),
>>> + },
>>> +};
>>> +
>>> +static int ads124s_write_cmd(struct iio_dev *indio_dev, u8 command)
>>> +{
>>> + struct ads124s_private *priv = iio_priv(indio_dev);
>>> +
>>> + priv->data[0] = command;
>>> +
>>> + return spi_write(priv->spi, &priv->data[0], 1);
>>> +}
>>> +
>>> +static int ads124s_write_reg(struct iio_dev *indio_dev, u8 reg, u8 data)
>>> +{
>>> + struct ads124s_private *priv = iio_priv(indio_dev);
>>> +
>>> + priv->data[0] = ADS124S08_CMD_WREG | reg;
>>> + priv->data[1] = 0x0;
>>> + priv->data[2] = data;
>>> +
>>> + return spi_write(priv->spi, &priv->data[0], 3);
>>> +}
>>> +
>>> +static int ads124s_reset(struct iio_dev *indio_dev)
>>> +{
>>> + struct ads124s_private *priv = iio_priv(indio_dev);
>>> +
>>> + if (priv->reset_gpio) {
>>> + gpiod_set_value(priv->reset_gpio, 0);
>>> + udelay(200);
>>> + gpiod_set_value(priv->reset_gpio, 1);
>>> + } else {
>>> + return ads124s_write_cmd(indio_dev, ADS124S08_CMD_RESET);
>>> + }
>>> +
>>> + return 0;
>>> +};
>>> +
>>> +static int ads124s_read(struct iio_dev *indio_dev, unsigned int chan)
>>> +{
>>> + struct ads124s_private *priv = iio_priv(indio_dev);
>>> + int ret;
>>> + u32 tmp;
>>> + struct spi_transfer t[] = {
>>> + {
>>> + .tx_buf = &priv->data[0],
>>> + .len = 4,
>>> + .cs_change = 1,
>>> + }, {
>>> + .tx_buf = &priv->data[1],
>>> + .rx_buf = &priv->data[1],
>>> + .len = 4,
>>> + },
>>> + };
>>> +
>>> + priv->data[0] = ADS124S08_CMD_RDATA;
>>> + memset(&priv->data[1], ADS124S08_CMD_NOP, sizeof(priv->data));
>>> +
>>> + ret = spi_sync_transfer(priv->spi, t, ARRAY_SIZE(t));
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + tmp = priv->data[2] << 16 | priv->data[3] << 8 | priv->data[4];
>>> +
>>> + return tmp;
>>> +}
>>> +
>>> +static int ads124s_read_raw(struct iio_dev *indio_dev,
>>> + struct iio_chan_spec const *chan,
>>> + int *val, int *val2, long m)
>>> +{
>>> + struct ads124s_private *priv = iio_priv(indio_dev);
>>> + int ret;
>>> +
>>> + mutex_lock(&priv->lock);
>>> + switch (m) {
>>> + case IIO_CHAN_INFO_RAW:
>>> + ret = ads124s_write_reg(indio_dev, ADS124S08_INPUT_MUX,
>>> + chan->channel);
>>> + if (ret) {
>>> + dev_err(&priv->spi->dev, "Set ADC CH failed\n");
>>> + goto out;
>>> + }
>>> +
>>> + ret = ads124s_write_cmd(indio_dev, ADS124S08_START_CONV);
>>> + if (ret) {
>>> + dev_err(&priv->spi->dev, "Start converions failed\n");
>>> + goto out;
>>> + }
>>> +
>>> + ret = ads124s_read(indio_dev, chan->channel);
>>> + if (ret < 0) {
>>> + dev_err(&priv->spi->dev, "Read ADC failed\n");
>>> + goto out;
>>> + } else
>>> + *val = ret;
>> Nit pick is that this doesn't benefit from being an else as it's just the normal
>> flow. Trivial though so lets just leave it!
>>
>>> +
>>> + ret = ads124s_write_cmd(indio_dev, ADS124S08_STOP_CONV);
>>> + if (ret) {
>>> + dev_err(&priv->spi->dev, "Stop converions failed\n");
>>> + goto out;
>>> + }
>>> +
>>> + ret = IIO_VAL_INT;
>>> + break;
>>> + default:
>>> + ret = -EINVAL;
>>> + break;
>>> + }
>>> +out:
>>> + mutex_unlock(&priv->lock);
>>> + return ret;
>>> +}
>>> +
>>> +static const struct iio_info ads124s_info = {
>>> + .read_raw = &ads124s_read_raw,
>>> +};
>>> +
>>> +static irqreturn_t ads124s_trigger_handler(int irq, void *p)
>>> +{
>>> + struct iio_poll_func *pf = p;
>>> + struct iio_dev *indio_dev = pf->indio_dev;
>>> + struct ads124s_private *priv = iio_priv(indio_dev);
>>> + u32 buffer[ADS124S08_MAX_CHANNELS + sizeof(s64)/sizeof(u16)];
>>> + int scan_index, j = 0;
>>> + int ret;
>>> +
>>> + for_each_set_bit(scan_index, indio_dev->active_scan_mask,
>>> + indio_dev->masklength) {
>>> + ret = ads124s_write_reg(indio_dev, ADS124S08_INPUT_MUX,
>>> + scan_index);
>>> + if (ret)
>>> + dev_err(&priv->spi->dev, "Set ADC CH failed\n");
>>> +
>>> + ret = ads124s_write_cmd(indio_dev, ADS124S08_START_CONV);
>>> + if (ret)
>>> + dev_err(&priv->spi->dev, "Start ADC converions failed\n");
>>> +
>>> + buffer[j] = ads124s_read(indio_dev, scan_index);
>>> + ret = ads124s_write_cmd(indio_dev, ADS124S08_STOP_CONV);
>>> + if (ret)
>>> + dev_err(&priv->spi->dev, "Stop ADC converions failed\n");
>>> +
>>> + j++;
>>> + }
>>> +
>>> + iio_push_to_buffers_with_timestamp(indio_dev, buffer,
>>> + pf->timestamp);
>>> +
>>> + iio_trigger_notify_done(indio_dev->trig);
>>> +
>>> + return IRQ_HANDLED;
>>> +}
>>> +
>>> +static int ads124s_probe(struct spi_device *spi)
>>> +{
>>> + struct ads124s_private *ads124s_priv;
>>> + struct iio_dev *indio_dev;
>>> + const struct spi_device_id *spi_id = spi_get_device_id(spi);
>>> + int ret;
>>> +
>>> + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*ads124s_priv));
>>> + if (indio_dev == NULL)
>>> + return -ENOMEM;
>>> +
>>> + ads124s_priv = iio_priv(indio_dev);
>>> +
>>> + ads124s_priv->reset_gpio = devm_gpiod_get_optional(&spi->dev,
>>> + "reset", GPIOD_OUT_LOW);
>>> + if (IS_ERR(ads124s_priv->reset_gpio))
>>> + dev_info(&spi->dev, "Reset GPIO not defined\n");
>>> +
>>> + ads124s_priv->chip_info = &ads124s_chip_info_tbl[spi_id->driver_data];
>>> +
>>> + spi_set_drvdata(spi, indio_dev);
>>> +
>>> + ads124s_priv->spi = spi;
>>> +
>>> + indio_dev->name = spi_id->name;
>>> + indio_dev->dev.parent = &spi->dev;
>>> + indio_dev->dev.of_node = spi->dev.of_node;
>>> + indio_dev->modes = INDIO_DIRECT_MODE;
>>> + indio_dev->channels = ads124s_priv->chip_info->channels;
>>> + indio_dev->num_channels = ads124s_priv->chip_info->num_channels;
>>> + indio_dev->info = &ads124s_info;
>>> +
>>> + mutex_init(&ads124s_priv->lock);
>>> +
>>> + ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL,
>>> + ads124s_trigger_handler, NULL);
>>> + if (ret) {
>>> + dev_err(&spi->dev, "iio triggered buffer setup failed\n");
>>> + return ret;
>>> + }
>>> +
>>> + ads124s_reset(indio_dev);
>>> +
>>> + return devm_iio_device_register(&spi->dev, indio_dev);
>>> +}
>>> +
>>> +static const struct spi_device_id ads124s_id[] = {
>>> + { "ads124s06", ADS124S06_ID },
>>> + { "ads124s08", ADS124S08_ID },
>>> + { }
>>> +};
>>> +MODULE_DEVICE_TABLE(spi, ads124s_id);
>>> +
>>> +static const struct of_device_id ads124s_of_table[] = {
>>> + { .compatible = "ti,ads124s06" },
>>> + { .compatible = "ti,ads124s08" },
>>> + { },
>>> +};
>>> +MODULE_DEVICE_TABLE(of, ads124s_of_table);
>>> +
>>> +static struct spi_driver ads124s_driver = {
>>> + .driver = {
>>> + .name = "ads124s08",
>>> + .of_match_table = ads124s_of_table,
>>> + },
>>> + .probe = ads124s_probe,
>>> + .id_table = ads124s_id,
>>> +};
>>> +module_spi_driver(ads124s_driver);
>>> +
>>> +MODULE_AUTHOR("Dan Murphy <dmuprhy@xxxxxx>");
>>> +MODULE_DESCRIPTION("TI TI_ADS12S0X ADC");
>>> +MODULE_LICENSE("GPL v2");
>>
>


--
------------------
Dan Murphy