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SubjectRe: [PATCH v3] IIO ADC support for AD7923
On 02/13/2013 09:20 AM, Jonathan Cameron wrote:
> On 13/02/13 09:19, Lars-Peter Clausen wrote:
>> On 02/13/2013 07:47 AM, Christophe Leroy wrote:
>>> This patch adds support for Analog Devices AD7923 ADC in the IIO Subsystem.
>>>
>>> Signed-off-by: Patrick Vasseur <patrick.vasseur@c-s.fr>
>>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>>
>> Looks good, thanks.
>>
>> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
> Just missed the merge window I'm afraid. I'll queue this up for
> going into staging-next after Linus closes the main merge window.

Applied to the togreg branch of iio.git
>>
>>>
>>> diff -urN linux-next-e347c98/drivers/iio/adc/Kconfig linux-next-e347c98.new/drivers/iio/adc/Kconfig
>>> --- linux-next-e347c98/drivers/iio/adc/Kconfig 2013-02-08 05:22:35.000000000 +0100
>>> +++ linux-next-e347c98.new/drivers/iio/adc/Kconfig 2013-02-12 13:02:52.000000000 +0100
>>> @@ -30,6 +30,18 @@
>>> To compile this driver as a module, choose M here: the
>>> module will be called ad7298.
>>>
>>> +config AD7923
>>> + tristate "Analog Devices AD7923 ADC driver"
>>> + depends on SPI
>>> + select IIO_BUFFER
>>> + select IIO_TRIGGERED_BUFFER
>>> + help
>>> + Say yes here to build support for Analog Devices AD7923
>>> + 4 Channel ADC with temperature sensor.
>>> +
>>> + To compile this driver as a module, choose M here: the
>>> + module will be called ad7923.
>>> +
>>> config AD7791
>>> tristate "Analog Devices AD7791 ADC driver"
>>> depends on SPI
>>> diff -urN linux-next-e347c98/drivers/iio/adc/Makefile linux-next-e347c98.new/drivers/iio/adc/Makefile
>>> --- linux-next-e347c98/drivers/iio/adc/Makefile 2013-02-08 05:22:35.000000000 +0100
>>> +++ linux-next-e347c98.new/drivers/iio/adc/Makefile 2013-02-12 13:03:02.000000000 +0100
>>> @@ -5,6 +5,7 @@
>>> obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
>>> obj-$(CONFIG_AD7266) += ad7266.o
>>> obj-$(CONFIG_AD7298) += ad7298.o
>>> +obj-$(CONFIG_AD7923) += ad7923.o
>>> obj-$(CONFIG_AD7476) += ad7476.o
>>> obj-$(CONFIG_AD7791) += ad7791.o
>>> obj-$(CONFIG_AD7793) += ad7793.o
>>> diff -urN linux-next-e347c98/drivers/iio/adc/ad7923.c linux-next-e347c98.new/drivers/iio/adc/ad7923.c
>>> --- linux-next-e347c98/drivers/iio/adc/ad7923.c 1970-01-01 01:00:00.000000000 +0100
>>> +++ linux-next-e347c98.new/drivers/iio/adc/ad7923.c 2013-02-13 02:03:38.000000000 +0100
>>> @@ -0,0 +1,298 @@
>>> +/*
>>> + * AD7923 SPI ADC driver
>>> + *
>>> + * Copyright 2011 Analog Devices Inc (from AD7923 Driver)
>>> + * Copyright 2012 CS Systemes d'Information
>>> + *
>>> + * Licensed under the GPL-2.
>>> + */
>>> +
>>> +#include <linux/device.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/sysfs.h>
>>> +#include <linux/spi/spi.h>
>>> +#include <linux/err.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/module.h>
>>> +#include <linux/interrupt.h>
>>> +
>>> +#include <linux/iio/iio.h>
>>> +#include <linux/iio/sysfs.h>
>>> +#include <linux/iio/buffer.h>
>>> +#include <linux/iio/trigger_consumer.h>
>>> +#include <linux/iio/triggered_buffer.h>
>>> +
>>> +#define AD7923_WRITE_CR (1 << 11) /* write control register */
>>> +#define AD7923_RANGE (1 << 1) /* range to REFin */
>>> +#define AD7923_CODING (1 << 0) /* coding is straight binary */
>>> +#define AD7923_PM_MODE_AS (1) /* auto shutdown */
>>> +#define AD7923_PM_MODE_FS (2) /* full shutdown */
>>> +#define AD7923_PM_MODE_OPS (3) /* normal operation */
>>> +#define AD7923_CHANNEL_0 (0) /* analog input 0 */
>>> +#define AD7923_CHANNEL_1 (1) /* analog input 1 */
>>> +#define AD7923_CHANNEL_2 (2) /* analog input 2 */
>>> +#define AD7923_CHANNEL_3 (3) /* analog input 3 */
>>> +#define AD7923_SEQUENCE_OFF (0) /* no sequence fonction */
>>> +#define AD7923_SEQUENCE_PROTECT (2) /* no interrupt write cycle */
>>> +#define AD7923_SEQUENCE_ON (3) /* continuous sequence */
>>> +
>>> +#define AD7923_MAX_CHAN 4
>>> +
>>> +#define AD7923_PM_MODE_WRITE(mode) (mode << 4) /* write mode */
>>> +#define AD7923_CHANNEL_WRITE(channel) (channel << 6) /* write channel */
>>> +#define AD7923_SEQUENCE_WRITE(sequence) (((sequence & 1) << 3) \
>>> + + ((sequence & 2) << 9))
>>> + /* write sequence fonction */
>>> +/* left shift for CR : bit 11 transmit in first */
>>> +#define AD7923_SHIFT_REGISTER 4
>>> +
>>> +/* val = value, dec = left shift, bits = number of bits of the mask */
>>> +#define EXTRACT(val, dec, bits) ((val >> dec) & ((1 << bits) - 1))
>>> +
>>> +struct ad7923_state {
>>> + struct spi_device *spi;
>>> + struct spi_transfer ring_xfer[5];
>>> + struct spi_transfer scan_single_xfer[2];
>>> + struct spi_message ring_msg;
>>> + struct spi_message scan_single_msg;
>>> + /*
>>> + * DMA (thus cache coherency maintenance) requires the
>>> + * transfer buffers to live in their own cache lines.
>>> + */
>>> + __be16 rx_buf[4] ____cacheline_aligned;
>>> + __be16 tx_buf[4];
>>> +};
>>> +
>>> +#define AD7923_V_CHAN(index) \
>>> + { \
>>> + .type = IIO_VOLTAGE, \
>>> + .indexed = 1, \
>>> + .channel = index, \
>>> + .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
>>> + IIO_CHAN_INFO_SCALE_SHARED_BIT, \
>>> + .address = index, \
>>> + .scan_index = index, \
>>> + .scan_type = { \
>>> + .sign = 'u', \
>>> + .realbits = 12, \
>>> + .storagebits = 16, \
>>> + .endianness = IIO_BE, \
>>> + }, \
>>> + }
>>> +
>>> +static const struct iio_chan_spec ad7923_channels[] = {
>>> + AD7923_V_CHAN(0),
>>> + AD7923_V_CHAN(1),
>>> + AD7923_V_CHAN(2),
>>> + AD7923_V_CHAN(3),
>>> + IIO_CHAN_SOFT_TIMESTAMP(4),
>>> +};
>>> +
>>> +/**
>>> + * ad7923_update_scan_mode() setup the spi transfer buffer for the new scan mask
>>> + **/
>>> +static int ad7923_update_scan_mode(struct iio_dev *indio_dev,
>>> + const unsigned long *active_scan_mask)
>>> +{
>>> + struct ad7923_state *st = iio_priv(indio_dev);
>>> + int i, cmd, len;
>>> +
>>> + len = 0;
>>> + for_each_set_bit(i, active_scan_mask, AD7923_MAX_CHAN) {
>>> + cmd = AD7923_WRITE_CR | AD7923_CODING | AD7923_RANGE |
>>> + AD7923_PM_MODE_WRITE(AD7923_PM_MODE_OPS) |
>>> + AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) |
>>> + AD7923_CHANNEL_WRITE(i);
>>> + cmd <<= AD7923_SHIFT_REGISTER;
>>> + st->tx_buf[len++] = cpu_to_be16(cmd);
>>> + }
>>> + /* build spi ring message */
>>> + st->ring_xfer[0].tx_buf = &st->tx_buf[0];
>>> + st->ring_xfer[0].len = len;
>>> + st->ring_xfer[0].cs_change = 1;
>>> +
>>> + spi_message_init(&st->ring_msg);
>>> + spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
>>> +
>>> + for (i = 0; i < len; i++) {
>>> + st->ring_xfer[i + 1].rx_buf = &st->rx_buf[i];
>>> + st->ring_xfer[i + 1].len = 2;
>>> + st->ring_xfer[i + 1].cs_change = 1;
>>> + spi_message_add_tail(&st->ring_xfer[i + 1], &st->ring_msg);
>>> + }
>>> + /* make sure last transfer cs_change is not set */
>>> + st->ring_xfer[i + 1].cs_change = 0;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>>> + * ad7923_trigger_handler() bh of trigger launched polling to ring buffer
>>> + *
>>> + * Currently there is no option in this driver to disable the saving of
>>> + * timestamps within the ring.
>>> + **/
>>> +static irqreturn_t ad7923_trigger_handler(int irq, void *p)
>>> +{
>>> + struct iio_poll_func *pf = p;
>>> + struct iio_dev *indio_dev = pf->indio_dev;
>>> + struct ad7923_state *st = iio_priv(indio_dev);
>>> + s64 time_ns = 0;
>>> + int b_sent;
>>> +
>>> + 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 + indio_dev->scan_bytes - sizeof(s64),
>>> + &time_ns, sizeof(time_ns));
>>> + }
>>> +
>>> + iio_push_to_buffers(indio_dev, (u8 *)st->rx_buf);
>>> +
>>> +done:
>>> + iio_trigger_notify_done(indio_dev->trig);
>>> +
>>> + return IRQ_HANDLED;
>>> +}
>>> +
>>> +static int ad7923_scan_direct(struct ad7923_state *st, unsigned ch)
>>> +{
>>> + int ret, cmd;
>>> +
>>> + cmd = AD7923_WRITE_CR | AD7923_PM_MODE_WRITE(AD7923_PM_MODE_OPS) |
>>> + AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) | AD7923_CODING |
>>> + AD7923_CHANNEL_WRITE(ch) | AD7923_RANGE;
>>> + cmd <<= AD7923_SHIFT_REGISTER;
>>> + st->tx_buf[0] = cpu_to_be16(cmd);
>>> +
>>> + ret = spi_sync(st->spi, &st->scan_single_msg);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + return be16_to_cpu(st->rx_buf[0]);
>>> +}
>>> +
>>> +static int ad7923_read_raw(struct iio_dev *indio_dev,
>>> + struct iio_chan_spec const *chan,
>>> + int *val,
>>> + int *val2,
>>> + long m)
>>> +{
>>> + int ret;
>>> + struct ad7923_state *st = iio_priv(indio_dev);
>>> +
>>> + switch (m) {
>>> + case IIO_CHAN_INFO_RAW:
>>> + mutex_lock(&indio_dev->mlock);
>>> + if (iio_buffer_enabled(indio_dev))
>>> + ret = -EBUSY;
>>> + else
>>> + ret = ad7923_scan_direct(st, chan->address);
>>> + mutex_unlock(&indio_dev->mlock);
>>> +
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + if (chan->address == EXTRACT(ret, 12, 4))
>>> + *val = EXTRACT(ret, 0, 12);
>>> +
>>> + return IIO_VAL_INT;
>>> + }
>>> + return -EINVAL;
>>> +}
>>> +
>>> +static const struct iio_info ad7923_info = {
>>> + .read_raw = &ad7923_read_raw,
>>> + .update_scan_mode = ad7923_update_scan_mode,
>>> + .driver_module = THIS_MODULE,
>>> +};
>>> +
>>> +static int ad7923_probe(struct spi_device *spi)
>>> +{
>>> + struct ad7923_state *st;
>>> + struct iio_dev *indio_dev = iio_device_alloc(sizeof(*st));
>>> + int ret;
>>> +
>>> + if (indio_dev == NULL)
>>> + return -ENOMEM;
>>> +
>>> + st = iio_priv(indio_dev);
>>> +
>>> + 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 = ad7923_channels;
>>> + indio_dev->num_channels = ARRAY_SIZE(ad7923_channels);
>>> + indio_dev->info = &ad7923_info;
>>> +
>>> + /* Setup default message */
>>> +
>>> + st->scan_single_xfer[0].tx_buf = &st->tx_buf[0];
>>> + st->scan_single_xfer[0].len = 2;
>>> + st->scan_single_xfer[0].cs_change = 1;
>>> + st->scan_single_xfer[1].rx_buf = &st->rx_buf[0];
>>> + st->scan_single_xfer[1].len = 2;
>>> +
>>> + spi_message_init(&st->scan_single_msg);
>>> + spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg);
>>> + spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg);
>>> +
>>> + ret = iio_triggered_buffer_setup(indio_dev, NULL,
>>> + &ad7923_trigger_handler, NULL);
>>> + if (ret)
>>> + goto error_free;
>>> +
>>> + ret = iio_device_register(indio_dev);
>>> + if (ret)
>>> + goto error_cleanup_ring;
>>> +
>>> + return 0;
>>> +
>>> +error_cleanup_ring:
>>> + iio_triggered_buffer_cleanup(indio_dev);
>>> +error_free:
>>> + iio_device_free(indio_dev);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int ad7923_remove(struct spi_device *spi)
>>> +{
>>> + struct iio_dev *indio_dev = spi_get_drvdata(spi);
>>> +
>>> + iio_device_unregister(indio_dev);
>>> + iio_triggered_buffer_cleanup(indio_dev);
>>> + iio_device_free(indio_dev);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static const struct spi_device_id ad7923_id[] = {
>>> + {"ad7923", 0},
>>> + {}
>>> +};
>>> +MODULE_DEVICE_TABLE(spi, ad7923_id);
>>> +
>>> +static struct spi_driver ad7923_driver = {
>>> + .driver = {
>>> + .name = "ad7923",
>>> + .owner = THIS_MODULE,
>>> + },
>>> + .probe = ad7923_probe,
>>> + .remove = ad7923_remove,
>>> + .id_table = ad7923_id,
>>> +};
>>> +module_spi_driver(ad7923_driver);
>>> +
>>> +MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
>>> +MODULE_AUTHOR("Patrick Vasseur <patrick.vasseur@c-s.fr>");
>>> +MODULE_DESCRIPTION("Analog Devices AD7923 ADC");
>>> +MODULE_LICENSE("GPL v2");
>>> --
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>>
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