This uses the iio sysfs interface, and inculdes gain
Signed-off-by: Paul Thomas <pthomas8589@xxxxxxxxx>
---
drivers/staging/iio/adc/Kconfig | 7 +
drivers/staging/iio/adc/Makefile | 1 +
drivers/staging/iio/adc/ad7194.c | 393 ++++++++++++++++++++++++++++++++++++++
3 files changed, 401 insertions(+), 0 deletions(-)
create mode 100644 drivers/staging/iio/adc/ad7194.c
diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
index 8c751c4..871605b 100644
--- a/drivers/staging/iio/adc/Kconfig
+++ b/drivers/staging/iio/adc/Kconfig
@@ -17,6 +17,13 @@ config AD7152
Say yes here to build support for Analog Devices capacitive sensors.
(ad7152, ad7153) Provides direct access via sysfs.
+config AD7194
+ tristate "Analog Devices AD7194 ADC driver"
+ depends on SPI
+ help
+ Say yes here to build support for Analog Devices ad7194.
+ Provides direct access via sysfs.
+
config AD7291
tristate "Analog Devices AD7291 temperature sensor driver"
depends on I2C
diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile
index 1d9b3f5..4da3c40 100644
--- a/drivers/staging/iio/adc/Makefile
+++ b/drivers/staging/iio/adc/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_AD7298) += ad7298.o
obj-$(CONFIG_AD7150) += ad7150.o
obj-$(CONFIG_AD7152) += ad7152.o
+obj-$(CONFIG_AD7194) += ad7194.o
obj-$(CONFIG_AD7291) += ad7291.o
obj-$(CONFIG_AD7314) += ad7314.o
obj-$(CONFIG_AD7745) += ad7745.o
diff --git a/drivers/staging/iio/adc/ad7194.c b/drivers/staging/iio/adc/ad7194.c
new file mode 100644
index 0000000..30d8378
--- /dev/null
+++ b/drivers/staging/iio/adc/ad7194.c
@@ -0,0 +1,393 @@
+/*
+ * ad7194 - driver for Analog Devices AD7194 A/D converter
+ *
+ * Copyright (c) 2011 Paul Thomas <pthomas8589@xxxxxxxxx>
+ *
+ * This program is distributed in the hope that 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 program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 or
+ * later as publishhed by the Free Software Foundation.
+ *
+ * You need to have something like this in struct spi_board_info
+ * {
+ * .modalias = "ad7194",
+ * .max_speed_hz = 2*1000*1000,
+ * .chip_select = 0,
+ * .bus_num = 1,
+ * },
+ *
+ * There is 1 universial gain that is used for each read.
+ */
+
+/*From Table 15 in the datasheet*/
+/*Register addresses*/
+#define REG_STATUS 0
+#define REG_MODE 1
+#define REG_CONF 2
+#define REG_DATA 3
+#define REG_ID 4
+#define REG_GPOCON 5
+#define REG_OFFSET 6
+#define REG_FS 7
+
+/*From Table 15 in the datasheet*/
+#define COMM_ADDR_bp 3
+#define COMM_READ_bm (1 << 6)
+
+#define CONF_CHOP_bm (1 << 23)
+#define CONF_PSEUDO_bm (1 << 18)
+#define CONF_BUF_bm (1 << 4)
+#define CONF_CHAN_NEG_bp 8
+#define CONF_CHAN_POS_bp 12
+
+
+#define MODE_MD_SINGLE_gc (0x01 << 21)
+#define MODE_MD_ZS_CAL_gc (0x04 << 21)
+#define MODE_MD_FS_CAL_gc (0x05 << 21)
+#define MODE_CLK_INTTRI_gc (0x02 << 18)
+/*Table 8 in the datasheet provides options for the Filter Word*/
+#define MODE_FILTER_WORD 1
+#define SETTLE_MS 2
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/spi/spi.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+
+#define DEVICE_NAME "ad7194"
+#define NUM_CHANNELS 16
+
+const uint8_t gains[8] = {1, 0, 0, 8, 16, 32, 64, 128};
+
+struct ad7194_state {
+ struct spi_device *spi_dev;
+ struct iio_dev *indio_dev;
+ uint8_t gain;
+ struct mutex lock;
+};
+
+static ssize_t show_gain(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7194_state *st = dev_info->dev_data;
+
+ return sprintf(buf, "%d\n", gains[st->gain]);
+}
+
+static ssize_t set_gain(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ uint8_t gain_real, i;
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7194_state *st = dev_info->dev_data;
+
+ gain_real = simple_strtol(buf, NULL, 10);
+ if (gain_real == 0)
+ return -EPERM;
+ for (i = 0; i < 8; i++) {
+ if (gains[i] == gain_real) {
+ st->gain = i;
+ return count;
+ }
+ }
+ return -EPERM;
+}
+
+static inline int ad7194_read_reg8(struct spi_device *spi,
+ int reg, uint8_t *val)
+{
+ int ret;
+ uint8_t tx[1], rx[1];
+
+ tx[0] = (COMM_READ_bm | (reg << COMM_ADDR_bp));
+
+ ret = spi_write_then_read(spi, tx, 1, rx, 1);
+ *val = rx[0];
+ return ret;
+}
+
+static inline int ad7194_read_reg24(struct spi_device *spi,
+ int reg, uint32_t *val)
+{
+ int ret;
+ uint8_t tx[1], rx[3];
+
+ tx[0] = (COMM_READ_bm | (reg << COMM_ADDR_bp));
+
+ ret = spi_write_then_read(spi, tx, 1, rx, 3);
+ *val = (rx[0] << 16) + (rx[1] << 8) + rx[2];
+ return ret;
+}
+
+static inline int ad7194_write_reg24(struct spi_device *spi,
+ int reg, uint32_t *val)
+{
+ uint8_t *tx;
+ tx = kmalloc(4, GFP_KERNEL);
+
+ tx[0] = (reg << COMM_ADDR_bp);
+ tx[1] = (*val >> 16) & 0xff;
+ tx[2] = (*val >> 8) & 0xff;
+ tx[3] = (*val >> 0) & 0xff;
+
+ return spi_write(spi, tx, 4);
+}
+
+static ssize_t show_voltage(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long m)
+{
+ uint32_t conf, mode, myval, sign;
+ uint8_t status;
+ int32_t whole, fract;
+ int ret;
+
+ struct ad7194_state *st = iio_priv(indio_dev);
+ struct spi_device *spi = st->spi_dev;
+
+ if (chan->type == IIO_IN_DIFF)
+ conf = CONF_CHOP_bm | CONF_BUF_bm |
+ ((chan->channel - 1) << CONF_CHAN_POS_bp) |
+ ((chan->channel2 - 1) << CONF_CHAN_NEG_bp) | st->gain;
+ else
+ conf = CONF_CHOP_bm | CONF_BUF_bm | CONF_PSEUDO_bm |
+ ((chan->channel - 1) << CONF_CHAN_POS_bp) | st->gain;
+
+ ret = mutex_lock_interruptible(&st->lock);
+ if (ret != 0)
+ return ret;
+
+ ret = ad7194_write_reg24(spi, REG_CONF, &conf);
+ if (ret != 0)
+ goto out;
+
+ mode = MODE_MD_SINGLE_gc | MODE_CLK_INTTRI_gc | MODE_FILTER_WORD;
+ ret = ad7194_write_reg24(spi, REG_MODE, &mode);
+ if (ret != 0)
+ goto out;
+
+ msleep_interruptible(SETTLE_MS);
+
+ ret = ad7194_read_reg8(spi, REG_STATUS, &status);
+ if (ret != 0)
+ goto out;
+ status = (status >> 6) & 0x01;
+
+ ret = ad7194_read_reg24(spi, REG_DATA, &myval);
+ if (ret != 0)
+ goto out;
+
+ sign = (myval & 0x800000) >> 23;
+ if (sign)
+ fract = (myval & 0x7fffff);
+ else
+ fract = 0x7fffff - (myval & 0x7fffff);
+ fract = ((int64_t)fract*4095000) >> 23;
+ fract = fract / gains[st->gain];
+ whole = fract / 1000000;
+ fract = fract % 1000000;
+
+ if (status == 0) {
+ mutex_unlock(&st->lock);
+ if (sign) {
+ *val = whole;
+ *val2 = fract;
+ } else {
+ *val = whole;
+ *val2 = -fract;
+ }
+ return IIO_VAL_INT_PLUS_MICRO;
+ } else {
+ ret = -EAGAIN;
+ goto out;
+ }
+
+out:
+ mutex_unlock(&st->lock);
+ return ret;
+}
+
+static struct iio_chan_spec ad7194_channels[] = {
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 1, 0, 0,
+ 0, 0, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 2, 0, 0,
+ 1, 1, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 3, 0, 0,
+ 2, 2, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 4, 0, 0,
+ 3, 3, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 5, 0, 0,
+ 4, 4, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 6, 0, 0,
+ 5, 5, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 7, 0, 0,
+ 6, 6, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 8, 0, 0,
+ 7, 7, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 9, 0, 0,
+ 8, 8, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 10, 0, 0,
+ 9, 9, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 11, 0, 0,
+ 10, 10, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 12, 0, 0,
+ 11, 11, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 13, 0, 0,
+ 12, 12, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 14, 0, 0,
+ 13, 13, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 15, 0, 0,
+ 14, 14, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 16, 0, 0,
+ 15, 15, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 1, 2, 0,
+ 16, 16, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 2, 1, 0,
+ 17, 17, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 3, 4, 0,
+ 18, 18, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 4, 3, 0,
+ 19, 19, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 5, 6, 0,
+ 20, 20, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 6, 5, 0,
+ 21, 21, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 7, 8, 0,
+ 22, 22, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 8, 7, 0,
+ 23, 23, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 9, 10, 0,
+ 24, 24, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 10, 9, 0,
+ 25, 25, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 11, 12, 0,
+ 26, 26, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 12, 11, 0,
+ 27, 27, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 13, 14, 0,
+ 28, 28, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 14, 13, 0,
+ 29, 29, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 15, 16, 0,
+ 30, 30, IIO_ST('s', 24, 32, 0), 0),
+ IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 16, 15, 0,
+ 31, 31, IIO_ST('s', 24, 32, 0), 0),
+};
+
+static IIO_DEVICE_ATTR(gain, S_IWUSR | S_IRUGO, show_gain, set_gain, -1);
+
+static struct attribute *ad7194_attributes[] = {
+ &iio_dev_attr_gain.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ad7194_attribute_group = {
+ .attrs = ad7194_attributes,
+};
+
+static const struct iio_info ad7194_info = {
+ .attrs = &ad7194_attribute_group,
+ .read_raw = &show_voltage,
+ .driver_module = THIS_MODULE,
+};
+
+static int __devinit ad7194_probe(struct spi_device *spi)
+{
+ int ret;
+ struct ad7194_state *st;
+ struct iio_dev *indio_dev;
+
+ /* Configure the SPI bus */
+ spi->mode = (SPI_MODE_0);
+ spi->bits_per_word = 8;
+ spi_setup(spi);
+
+ indio_dev = iio_allocate_device(sizeof(struct ad7194_state));
+ if (indio_dev == NULL) {
+ ret = -ENOMEM;
+ goto exit;
+ }
+ st = iio_priv(indio_dev);
+
+ dev_set_drvdata(&spi->dev, st);
+
+ st->spi_dev = spi;
+
+ st->indio_dev = iio_allocate_device(0);
+ if (st->indio_dev == NULL) {
+ ret = -ENOMEM;
+ goto error_free;
+ }
+
+ spi_set_drvdata(spi, indio_dev);
+ st->spi_dev = spi;
+
+ mutex_init(&st->lock);
+ indio_dev->name = "ad7194";
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->info = &ad7194_info;
+ indio_dev->dev_data = (void *)st;
+ indio_dev->channels = ad7194_channels;
+ indio_dev->num_channels = ARRAY_SIZE(ad7194_channels);
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error_free_dev;
+
+ return 0;
+
+error_free_dev:
+ iio_free_device(st->indio_dev);
+error_free:
+ kfree(st);
+exit:
+ return ret;
+}
+
+static int __devexit ad7194_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ iio_device_unregister(indio_dev);
+ return 0;
+}
+
+static struct spi_driver ad7194_driver = {
+ .driver = {
+ .name = DEVICE_NAME,
+ .bus = &spi_bus_type,
+ .owner = THIS_MODULE,
+ },
+
+ .probe = ad7194_probe,
+ .remove = __devexit_p(ad7194_remove),
+};
+
+static int __init ad7194_init(void)
+{
+ return spi_register_driver(&ad7194_driver);
+}
+
+static void __exit ad7194_exit(void)
+{
+ spi_unregister_driver(&ad7194_driver);
+}
+
+module_init(ad7194_init);
+module_exit(ad7194_exit);
+
+MODULE_AUTHOR("Paul Thomas <pthomas8589@xxxxxxxxx>");
+MODULE_DESCRIPTION("Analog Devices AD7194 A/D driver");
+MODULE_LICENSE("GPL");
--
1.6.2.5
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