[linux-yocto] [PATCH 25/29] staging:iio: add support for ADC1x8s102.
Paul Gortmaker
paul.gortmaker at windriver.com
Sun Feb 7 14:45:26 PST 2016
[[linux-yocto] [PATCH 25/29] staging:iio: add support for ADC1x8s102.] On 05/02/2016 (Fri 06:53) Saul Wold wrote:
> From: Todor Minchev <todor at minchev.co.uk>
>
> Upstream-status: Pending
>
> Signed-off-by: Saul Wold <sgw at linux.intel.com>
The patch pending for upstream doesn't have any commit log or SOB lines
for the original author? I'm guessing pending preceeds submitted so
this doesn't reflect what the final version will be?
Seems odd to have that obvious an omission so I thought I'd mention it
in case some script went rogue and ate it.
P.
--
> ---
> drivers/staging/iio/adc/Kconfig | 13 ++
> drivers/staging/iio/adc/Makefile | 1 +
> drivers/staging/iio/adc/adc1x8s102.c | 387 +++++++++++++++++++++++++++++++
> include/linux/platform_data/adc1x8s102.h | 30 +++
> 4 files changed, 431 insertions(+)
> create mode 100644 drivers/staging/iio/adc/adc1x8s102.c
> create mode 100644 include/linux/platform_data/adc1x8s102.h
>
> diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
> index d0016ce..7d295a6 100644
> --- a/drivers/staging/iio/adc/Kconfig
> +++ b/drivers/staging/iio/adc/Kconfig
> @@ -115,4 +115,17 @@ config SPEAR_ADC
>
> To compile this driver as a module, choose M here: the
> module will be called spear_adc.
> +
> +config ADC1x8S102
> + tristate "Texas Instruments ADC1x8S102 driver"
> + depends on SPI
> + select IIO_BUFFER
> + select IIO_TRIGGERED_BUFFER
> + help
> + Say yes here to build support for Texas Instruments ADC1x8S102 ADC.
> + Provides direct access via sysfs.
> +
> + To compile this driver as a module, choose M here: the module will
> + be called adc1x8s102
> +
> endmenu
> diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile
> index 1c4277d..3fe3880 100644
> --- a/drivers/staging/iio/adc/Makefile
> +++ b/drivers/staging/iio/adc/Makefile
> @@ -15,3 +15,4 @@ obj-$(CONFIG_AD7280) += ad7280a.o
> obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
> obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o
> obj-$(CONFIG_SPEAR_ADC) += spear_adc.o
> +obj-$(CONFIG_ADC1x8S102) += adc1x8s102.o
> diff --git a/drivers/staging/iio/adc/adc1x8s102.c b/drivers/staging/iio/adc/adc1x8s102.c
> new file mode 100644
> index 0000000..52472e2
> --- /dev/null
> +++ b/drivers/staging/iio/adc/adc1x8s102.c
> @@ -0,0 +1,387 @@
> +/*
> + * ADC1x8S102 SPI ADC driver
> + *
> + * Copyright(c) 2013 Intel Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + *
> + * This IIO device driver is is designed to work with the following
> + * analog to digital converters from Texas Instruments:
> + * ADC108S102
> + * ADC128S102
> + * The communication with ADC chip is via the SPI bus (mode 3).
> + */
> +
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/types.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/spi/spi.h>
> +
> +#include <linux/platform_data/adc1x8s102.h>
> +#include <linux/regulator/consumer.h>
> +
> +/*
> + * Defining the ADC resolution being 12 bits, we can use the same driver for
> + * both ADC108S102 (10 bits resolution) and ADC128S102 (12 bits resolution)
> + * chips. The ADC108S102 effectively returns a 12-bit result with the 2
> + * least-significant bits unset.
> + */
> +#define ADC1x8S102_BITS 12
> +#define ADC1x8S102_MAX_CHANNELS 8
> +
> +/* 16-bit SPI command format:
> + * [15:14] Ignored
> + * [13:11] 3-bit channel address
> + * [10:0] Ignored
> + */
> +#define ADC1x8S102_CMD(ch) (((ch) << (8)) << (3))
> +
> +/*
> + * 16-bit SPI response format:
> + * [15:12] Zeros
> + * [11:0] 12-bit ADC sample (for ADC108S102, [1:0] will always be 0).
> + */
> +#define ADC1x8S102_RES_DATA(res) (res & ((1 << ADC1x8S102_BITS) - 1))
> +
> +struct adc1x8s102_state {
> + struct spi_device *spi;
> + struct regulator *reg;
> + u16 ext_vin;
> + /* SPI transfer used by triggered buffer handler*/
> + struct spi_transfer ring_xfer;
> + /* SPI transfer used by direct scan */
> + struct spi_transfer scan_single_xfer;
> + /* SPI message used by ring_xfer SPI transfer */
> + struct spi_message ring_msg;
> + /* SPI message used by scan_single_xfer SPI transfer */
> + struct spi_message scan_single_msg;
> +
> + /* SPI message buffers:
> + * tx_buf: |C0|C1|C2|C3|C4|C5|C6|C7|XX|
> + * rx_buf: |XX|R0|R1|R2|R3|R4|R5|R6|R7|tt|tt|tt|tt|
> + *
> + * tx_buf: 8 channel read commands, plus 1 dummy command
> + * rx_buf: 1 dummy response, 8 channel responses, plus 64-bit timestamp
> + */
> + __be16 rx_buf[13] ____cacheline_aligned;
> + __be16 tx_buf[9];
> +
> +};
> +
> +#define ADC1X8S102_V_CHAN(index) \
> + { \
> + .type = IIO_VOLTAGE, \
> + .indexed = 1, \
> + .channel = index, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> + BIT(IIO_CHAN_INFO_SCALE), \
> + .address = index, \
> + .scan_index = index, \
> + .scan_type = { \
> + .sign = 'u', \
> + .realbits = ADC1x8S102_BITS, \
> + .storagebits = 16, \
> + .endianness = IIO_BE, \
> + }, \
> + }
> +
> +static const struct iio_chan_spec adc1x8s102_channels[] = {
> + ADC1X8S102_V_CHAN(0),
> + ADC1X8S102_V_CHAN(1),
> + ADC1X8S102_V_CHAN(2),
> + ADC1X8S102_V_CHAN(3),
> + ADC1X8S102_V_CHAN(4),
> + ADC1X8S102_V_CHAN(5),
> + ADC1X8S102_V_CHAN(6),
> + ADC1X8S102_V_CHAN(7),
> + IIO_CHAN_SOFT_TIMESTAMP(8),
> +};
> +
> +
> +static int adc1x8s102_update_scan_mode(struct iio_dev *indio_dev,
> + unsigned long const *active_scan_mask)
> +{
> + struct adc1x8s102_state *st;
> + int i, j;
> +
> + st = iio_priv(indio_dev);
> +
> + /* Fill in the first x shorts of tx_buf with the number of channels
> + * enabled for sampling by the triggered buffer
> + */
> + for (i = 0, j = 0; i < ADC1x8S102_MAX_CHANNELS; i++) {
> + if (test_bit(i, active_scan_mask)) {
> + st->tx_buf[j] = cpu_to_be16(ADC1x8S102_CMD(i));
> + j++;
> + }
> + }
> + /* One dummy command added, to clock in the last response */
> + st->tx_buf[j] = 0x00;
> +
> + /* build SPI ring message */
> + st->ring_xfer.tx_buf = &st->tx_buf[0];
> + st->ring_xfer.rx_buf = &st->rx_buf[0];
> + st->ring_xfer.len = (j + 1) * sizeof(__be16);
> +
> + spi_message_init(&st->ring_msg);
> + spi_message_add_tail(&st->ring_xfer, &st->ring_msg);
> +
> + return 0;
> +}
> +
> +
> +static irqreturn_t adc1x8s102_trigger_handler(int irq, void *p)
> +{
> + struct iio_poll_func *pf = p;
> + struct iio_dev *indio_dev;
> + struct adc1x8s102_state *st;
> + s64 time_ns = 0;
> + int b_sent;
> +
> + indio_dev = pf->indio_dev;
> + st = iio_priv(indio_dev);
> +
> + b_sent = spi_sync(st->spi, &st->ring_msg);
> + if (b_sent)
> + goto done;
> + if (indio_dev->scan_timestamp) {
> + time_ns = iio_get_time_ns();
> + memcpy((u8 *)st->rx_buf + st->ring_xfer.len, &time_ns,
> + sizeof(time_ns));
> + }
> +
> + /* Skip the dummy response in the first slot */
> + iio_push_to_buffers(indio_dev, (u8 *)&st->rx_buf[1]);
> +done:
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + return IRQ_HANDLED;
> +}
> +
> +
> +/*
> + * returns:
> + * positive (>=0) value => SUCCESS
> + * negative value => FAILURE
> + */
> +static int adc1x8s102_scan_direct(struct adc1x8s102_state *st, unsigned ch)
> +{
> + int ret;
> +
> + if (ch >= ADC1x8S102_MAX_CHANNELS) {
> + dev_err(&st->spi->dev, "AD channel number too big: %u\n", ch);
> + return -1;
> + }
> +
> + st->tx_buf[0] = cpu_to_be16(ADC1x8S102_CMD(ch));
> + ret = spi_sync(st->spi, &st->scan_single_msg);
> + if (ret)
> + return ret;
> +
> + /* Skip the dummy response in the first slot */
> + return be16_to_cpu(st->rx_buf[1]);
> +}
> +
> +
> +/*
> + * returns:
> + * positive (>=0) value => SUCCESS
> + * negative value => FAILURE
> + */
> +static int adc1x8s102_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val,
> + int *val2,
> + long m)
> +{
> + int ret;
> + struct adc1x8s102_state *st;
> +
> + st = iio_priv(indio_dev);
> +
> + switch (m) {
> + case IIO_CHAN_INFO_RAW:
> + mutex_lock(&indio_dev->mlock);
> + if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
> + ret = -EBUSY;
> + dev_warn(&st->spi->dev,
> + "indio_dev->currentmode is INDIO_BUFFER_TRIGGERED\n");
> + } else {
> + ret = adc1x8s102_scan_direct(st, chan->address);
> + }
> + mutex_unlock(&indio_dev->mlock);
> +
> + if (ret < 0)
> + return ret;
> + *val = ADC1x8S102_RES_DATA(ret);
> +
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + switch (chan->type) {
> + case IIO_VOLTAGE:
> + if (NULL != st->reg)
> + *val = regulator_get_voltage(st->reg) / 1000;
> + else
> + *val = st->ext_vin;
> +
> + *val2 = chan->scan_type.realbits;
> + return IIO_VAL_FRACTIONAL_LOG2;
> + default:
> + dev_warn(&st->spi->dev,
> + "Invalid channel type %u for channel %d\n",
> + chan->type, chan->channel);
> + return -EINVAL;
> + }
> + default:
> + dev_warn(&st->spi->dev, "Invalid IIO_CHAN_INFO: %lu\n", m);
> + return -EINVAL;
> + }
> +}
> +
> +
> +
> +static const struct iio_info adc1x8s102_info = {
> + .read_raw = &adc1x8s102_read_raw,
> + .update_scan_mode = &adc1x8s102_update_scan_mode,
> + .driver_module = THIS_MODULE,
> +};
> +
> +
> +static int adc1x8s102_probe(struct spi_device *spi)
> +{
> + struct adc1x8s102_platform_data *pdata = spi->dev.platform_data;
> + struct adc1x8s102_state *st;
> + struct iio_dev *indio_dev = iio_device_alloc(sizeof(*st));
> + int ret;
> +
> + if (NULL == indio_dev) {
> + dev_crit(&spi->dev, "Cannot allocate memory for indio_dev\n");
> + return -ENOMEM;
> + }
> +
> + st = iio_priv(indio_dev);
> + if (NULL == pdata) {
> + dev_err(&spi->dev, "Cannot get adc1x8s102 platform data\n");
> + return -EFAULT;
> + }
> + st->ext_vin = pdata->ext_vin;
> +
> + /* Use regulator, if available. */
> + st->reg = regulator_get(&spi->dev, "vref");
> + if (IS_ERR(st->reg)) {
> + ret = PTR_ERR(st->reg);
> + dev_warn(&spi->dev,
> + "Cannot get 'vref' regulator\n");
> + goto error_free;
> + }
> + ret = regulator_enable(st->reg);
> + if (ret < 0) {
> + dev_warn(&spi->dev,
> + "Cannot enable vref regulator\n");
> + goto error_put_reg;
> + }
> +
> + 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 = adc1x8s102_channels;
> + indio_dev->num_channels = ARRAY_SIZE(adc1x8s102_channels);
> + indio_dev->info = &adc1x8s102_info;
> +
> + /* Setup default message */
> + st->scan_single_xfer.tx_buf = st->tx_buf;
> + st->scan_single_xfer.rx_buf = st->rx_buf;
> + st->scan_single_xfer.len = 2 * sizeof(__be16);
> + st->scan_single_xfer.cs_change = 0;
> +
> + spi_message_init(&st->scan_single_msg);
> + spi_message_add_tail(&st->scan_single_xfer, &st->scan_single_msg);
> +
> + ret = iio_triggered_buffer_setup(indio_dev, NULL,
> + &adc1x8s102_trigger_handler, NULL);
> + if (ret)
> + goto error_disable_reg;
> +
> + ret = iio_device_register(indio_dev);
> + if (ret) {
> + dev_err(&spi->dev,
> + "Failed to register IIO device\n");
> + goto error_cleanup_ring;
> + }
> + return 0;
> +
> +error_cleanup_ring:
> + iio_triggered_buffer_cleanup(indio_dev);
> +error_disable_reg:
> + regulator_disable(st->reg);
> +error_put_reg:
> + regulator_put(st->reg);
> +error_free:
> + iio_device_free(indio_dev);
> +
> + return ret;
> +}
> +
> +
> +static int adc1x8s102_remove(struct spi_device *spi)
> +{
> + struct iio_dev *indio_dev;
> + struct adc1x8s102_state *st;
> +
> + indio_dev = spi_get_drvdata(spi);
> + if (NULL == indio_dev) {
> + dev_err(&spi->dev, "Cannot get spi_device drvdata\n");
> + return -EFAULT;
> + }
> +
> + st = iio_priv(indio_dev);
> +
> + iio_device_unregister(indio_dev);
> +
> + iio_triggered_buffer_cleanup(indio_dev);
> +
> + regulator_disable(st->reg);
> + regulator_put(st->reg);
> +
> + iio_device_free(indio_dev);
> +
> + return 0;
> +}
> +
> +
> +static const struct spi_device_id adc1x8s102_id[] = {
> + {"adc1x8s102", 0},
> + {}
> +};
> +MODULE_DEVICE_TABLE(spi, adc1x8s102_id);
> +
> +static struct spi_driver adc1x8s102_driver = {
> + .driver = {
> + .name = "adc1x8s102",
> + .owner = THIS_MODULE,
> + },
> + .probe = adc1x8s102_probe,
> + .remove = adc1x8s102_remove,
> + .id_table = adc1x8s102_id,
> +};
> +module_spi_driver(adc1x8s102_driver);
> +
> +MODULE_AUTHOR("Bogdan Pricop <bogdan.pricop at emutex.com>");
> +MODULE_DESCRIPTION("Texas Instruments ADC1x8S102 driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/platform_data/adc1x8s102.h b/include/linux/platform_data/adc1x8s102.h
> new file mode 100644
> index 0000000..a32a499
> --- /dev/null
> +++ b/include/linux/platform_data/adc1x8s102.h
> @@ -0,0 +1,30 @@
> +/*
> + * ADC1x8S102 SPI ADC driver
> + *
> + * Copyright(c) 2013 Intel Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + */
> +
> +
> +#ifndef __LINUX_PLATFORM_DATA_ADC1x8S102_H__
> +#define __LINUX_PLATFORM_DATA_ADC1x8S102_H__
> +
> +
> +/**
> + * struct adc1x8s102_platform_data - Platform data for the adc1x8s102 ADC driver
> + * @ext_vin: External input voltage range for all voltage input channels
> + * This is the voltage level of pin VA in millivolts
> + **/
> +struct adc1x8s102_platform_data {
> + u16 ext_vin;
> +};
> +
> +#endif /* __LINUX_PLATFORM_DATA_ADC1x8S102_H__ */
> --
> 2.5.0
>
> --
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