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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-11 13:59:44 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-11 13:59:44 -0800
commit8966961b31c251b854169e9886394c2a20f2cea7 (patch)
tree248a625b23335acbd5ca4b55eb136fe0dc8ba0aa /drivers/iio/adc/ad7887.c
parentMerge tag 'char-misc-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc (diff)
parentMerge tag 'iio-for-3.8f' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next (diff)
downloadlinux-dev-8966961b31c251b854169e9886394c2a20f2cea7.tar.xz
linux-dev-8966961b31c251b854169e9886394c2a20f2cea7.zip
Merge tag 'staging-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging driver tree merge from Greg Kroah-Hartman: "Here's the big staging tree merge for 3.8-rc1 There's a lot of patches in here, the majority being the comedi rework/cleanup that has been ongoing and is causing a huge reduction in overall code size, which is amazing to watch. We also removed some older drivers (telephony and rts_pstor), and added a new one (fwserial which also came in through the tty tree due to tty api changes, take that one if you get merge conflicts.) The iio and ipack drivers are moving out of the staging area into their own part of the kernel as they have been cleaned up sufficiently and are working well. Overall, again a reduction of code: 768 files changed, 31887 insertions(+), 82166 deletions(-) All of this has been in the linux-next tree for a while. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" * tag 'staging-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1298 commits) iio: imu: adis16480: remove duplicated include from adis16480.c iio: gyro: adis16136: remove duplicated include from adis16136.c iio:imu: adis16480: show_firmware() buffer too small iio:gyro: adis16136: divide by zero in write_frequency() iio: adc: Add Texas Instruments ADC081C021/027 support iio:ad7793: Add support for the ad7796 and ad7797 iio:ad7793: Add support for the ad7798 and ad7799 staging:iio: Move ad7793 driver out of staging staging:iio:ad7793: Implement stricter id checking staging:iio:ad7793: Move register definitions from header to source staging:iio:ad7793: Rework regulator handling staging:iio:ad7793: Rework platform data staging:iio:ad7793: Use kstrtol instead of strict_strtol staging:iio:ad7793: Use usleep_range instead of msleep staging:iio:ad7793: Fix temperature scale staging:iio:ad7793: Fix VDD monitor scale staging: gdm72xx: unlock on error in init_usb() staging: panel: pass correct lengths to keypad_send_key() staging: comedi: addi_apci_2032: fix interrupt support staging: comedi: addi_apci_2032: move i_APCI2032_ConfigDigitalOutput() ...
Diffstat (limited to 'drivers/iio/adc/ad7887.c')
-rw-r--r--drivers/iio/adc/ad7887.c378
1 files changed, 378 insertions, 0 deletions
diff --git a/drivers/iio/adc/ad7887.c b/drivers/iio/adc/ad7887.c
new file mode 100644
index 000000000000..81153fafac7a
--- /dev/null
+++ b/drivers/iio/adc/ad7887.c
@@ -0,0 +1,378 @@
+/*
+ * AD7887 SPI ADC driver
+ *
+ * Copyright 2010-2011 Analog Devices Inc.
+ *
+ * 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/regulator/consumer.h>
+#include <linux/err.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>
+
+#include <linux/platform_data/ad7887.h>
+
+#define AD7887_REF_DIS (1 << 5) /* on-chip reference disable */
+#define AD7887_DUAL (1 << 4) /* dual-channel mode */
+#define AD7887_CH_AIN1 (1 << 3) /* convert on channel 1, DUAL=1 */
+#define AD7887_CH_AIN0 (0 << 3) /* convert on channel 0, DUAL=0,1 */
+#define AD7887_PM_MODE1 (0) /* CS based shutdown */
+#define AD7887_PM_MODE2 (1) /* full on */
+#define AD7887_PM_MODE3 (2) /* auto shutdown after conversion */
+#define AD7887_PM_MODE4 (3) /* standby mode */
+
+enum ad7887_channels {
+ AD7887_CH0,
+ AD7887_CH0_CH1,
+ AD7887_CH1,
+};
+
+#define RES_MASK(bits) ((1 << (bits)) - 1)
+
+/**
+ * struct ad7887_chip_info - chip specifc information
+ * @int_vref_mv: the internal reference voltage
+ * @channel: channel specification
+ */
+struct ad7887_chip_info {
+ u16 int_vref_mv;
+ struct iio_chan_spec channel[3];
+};
+
+struct ad7887_state {
+ struct spi_device *spi;
+ const struct ad7887_chip_info *chip_info;
+ struct regulator *reg;
+ struct spi_transfer xfer[4];
+ struct spi_message msg[3];
+ struct spi_message *ring_msg;
+ unsigned char tx_cmd_buf[4];
+
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ * Buffer needs to be large enough to hold two 16 bit samples and a
+ * 64 bit aligned 64 bit timestamp.
+ */
+ unsigned char data[ALIGN(4, sizeof(s64)) + sizeof(s64)]
+ ____cacheline_aligned;
+};
+
+enum ad7887_supported_device_ids {
+ ID_AD7887
+};
+
+static int ad7887_ring_preenable(struct iio_dev *indio_dev)
+{
+ struct ad7887_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = iio_sw_buffer_preenable(indio_dev);
+ if (ret < 0)
+ return ret;
+
+ /* We know this is a single long so can 'cheat' */
+ switch (*indio_dev->active_scan_mask) {
+ case (1 << 0):
+ st->ring_msg = &st->msg[AD7887_CH0];
+ break;
+ case (1 << 1):
+ st->ring_msg = &st->msg[AD7887_CH1];
+ /* Dummy read: push CH1 setting down to hardware */
+ spi_sync(st->spi, st->ring_msg);
+ break;
+ case ((1 << 1) | (1 << 0)):
+ st->ring_msg = &st->msg[AD7887_CH0_CH1];
+ break;
+ }
+
+ return 0;
+}
+
+static int ad7887_ring_postdisable(struct iio_dev *indio_dev)
+{
+ struct ad7887_state *st = iio_priv(indio_dev);
+
+ /* dummy read: restore default CH0 settin */
+ return spi_sync(st->spi, &st->msg[AD7887_CH0]);
+}
+
+/**
+ * ad7887_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 ad7887_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct ad7887_state *st = iio_priv(indio_dev);
+ s64 time_ns;
+ int b_sent;
+
+ b_sent = spi_sync(st->spi, st->ring_msg);
+ if (b_sent)
+ goto done;
+
+ time_ns = iio_get_time_ns();
+
+ if (indio_dev->scan_timestamp)
+ memcpy(st->data + indio_dev->scan_bytes - sizeof(s64),
+ &time_ns, sizeof(time_ns));
+
+ iio_push_to_buffers(indio_dev, st->data);
+done:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static const struct iio_buffer_setup_ops ad7887_ring_setup_ops = {
+ .preenable = &ad7887_ring_preenable,
+ .postenable = &iio_triggered_buffer_postenable,
+ .predisable = &iio_triggered_buffer_predisable,
+ .postdisable = &ad7887_ring_postdisable,
+};
+
+static int ad7887_scan_direct(struct ad7887_state *st, unsigned ch)
+{
+ int ret = spi_sync(st->spi, &st->msg[ch]);
+ if (ret)
+ return ret;
+
+ return (st->data[(ch * 2)] << 8) | st->data[(ch * 2) + 1];
+}
+
+static int ad7887_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long m)
+{
+ int ret;
+ struct ad7887_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 = ad7887_scan_direct(st, chan->address);
+ mutex_unlock(&indio_dev->mlock);
+
+ if (ret < 0)
+ return ret;
+ *val = ret >> chan->scan_type.shift;
+ *val &= RES_MASK(chan->scan_type.realbits);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ if (st->reg) {
+ *val = regulator_get_voltage(st->reg);
+ if (*val < 0)
+ return *val;
+ *val /= 1000;
+ } else {
+ *val = st->chip_info->int_vref_mv;
+ }
+
+ *val2 = chan->scan_type.realbits;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+ }
+ return -EINVAL;
+}
+
+
+static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
+ /*
+ * More devices added in future
+ */
+ [ID_AD7887] = {
+ .channel[0] = {
+ .type = IIO_VOLTAGE,
+ .indexed = 1,
+ .channel = 1,
+ .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
+ IIO_CHAN_INFO_SCALE_SHARED_BIT,
+ .address = 1,
+ .scan_index = 1,
+ .scan_type = IIO_ST('u', 12, 16, 0),
+ },
+ .channel[1] = {
+ .type = IIO_VOLTAGE,
+ .indexed = 1,
+ .channel = 0,
+ .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
+ IIO_CHAN_INFO_SCALE_SHARED_BIT,
+ .address = 0,
+ .scan_index = 0,
+ .scan_type = IIO_ST('u', 12, 16, 0),
+ },
+ .channel[2] = IIO_CHAN_SOFT_TIMESTAMP(2),
+ .int_vref_mv = 2500,
+ },
+};
+
+static const struct iio_info ad7887_info = {
+ .read_raw = &ad7887_read_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static int __devinit ad7887_probe(struct spi_device *spi)
+{
+ struct ad7887_platform_data *pdata = spi->dev.platform_data;
+ struct ad7887_state *st;
+ struct iio_dev *indio_dev = iio_device_alloc(sizeof(*st));
+ uint8_t mode;
+ int ret;
+
+ if (indio_dev == NULL)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+
+ if (!pdata || !pdata->use_onchip_ref) {
+ st->reg = regulator_get(&spi->dev, "vref");
+ if (IS_ERR(st->reg)) {
+ ret = PTR_ERR(st->reg);
+ goto error_free;
+ }
+
+ ret = regulator_enable(st->reg);
+ if (ret)
+ goto error_put_reg;
+ }
+
+ st->chip_info =
+ &ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+
+ spi_set_drvdata(spi, indio_dev);
+ st->spi = spi;
+
+ /* Estabilish that the iio_dev is a child of the spi device */
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->info = &ad7887_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ /* Setup default message */
+
+ mode = AD7887_PM_MODE4;
+ if (!pdata || !pdata->use_onchip_ref)
+ mode |= AD7887_REF_DIS;
+ if (pdata && pdata->en_dual)
+ mode |= AD7887_DUAL;
+
+ st->tx_cmd_buf[0] = AD7887_CH_AIN0 | mode;
+
+ st->xfer[0].rx_buf = &st->data[0];
+ st->xfer[0].tx_buf = &st->tx_cmd_buf[0];
+ st->xfer[0].len = 2;
+
+ spi_message_init(&st->msg[AD7887_CH0]);
+ spi_message_add_tail(&st->xfer[0], &st->msg[AD7887_CH0]);
+
+ if (pdata && pdata->en_dual) {
+ st->tx_cmd_buf[2] = AD7887_CH_AIN1 | mode;
+
+ st->xfer[1].rx_buf = &st->data[0];
+ st->xfer[1].tx_buf = &st->tx_cmd_buf[2];
+ st->xfer[1].len = 2;
+
+ st->xfer[2].rx_buf = &st->data[2];
+ st->xfer[2].tx_buf = &st->tx_cmd_buf[0];
+ st->xfer[2].len = 2;
+
+ spi_message_init(&st->msg[AD7887_CH0_CH1]);
+ spi_message_add_tail(&st->xfer[1], &st->msg[AD7887_CH0_CH1]);
+ spi_message_add_tail(&st->xfer[2], &st->msg[AD7887_CH0_CH1]);
+
+ st->xfer[3].rx_buf = &st->data[2];
+ st->xfer[3].tx_buf = &st->tx_cmd_buf[2];
+ st->xfer[3].len = 2;
+
+ spi_message_init(&st->msg[AD7887_CH1]);
+ spi_message_add_tail(&st->xfer[3], &st->msg[AD7887_CH1]);
+
+ indio_dev->channels = st->chip_info->channel;
+ indio_dev->num_channels = 3;
+ } else {
+ indio_dev->channels = &st->chip_info->channel[1];
+ indio_dev->num_channels = 2;
+ }
+
+ ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
+ &ad7887_trigger_handler, &ad7887_ring_setup_ops);
+ if (ret)
+ goto error_disable_reg;
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error_unregister_ring;
+
+ return 0;
+error_unregister_ring:
+ iio_triggered_buffer_cleanup(indio_dev);
+error_disable_reg:
+ if (st->reg)
+ regulator_disable(st->reg);
+error_put_reg:
+ if (st->reg)
+ regulator_put(st->reg);
+error_free:
+ iio_device_free(indio_dev);
+
+ return ret;
+}
+
+static int __devexit ad7887_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct ad7887_state *st = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
+ if (st->reg) {
+ regulator_disable(st->reg);
+ regulator_put(st->reg);
+ }
+ iio_device_free(indio_dev);
+
+ return 0;
+}
+
+static const struct spi_device_id ad7887_id[] = {
+ {"ad7887", ID_AD7887},
+ {}
+};
+MODULE_DEVICE_TABLE(spi, ad7887_id);
+
+static struct spi_driver ad7887_driver = {
+ .driver = {
+ .name = "ad7887",
+ .owner = THIS_MODULE,
+ },
+ .probe = ad7887_probe,
+ .remove = __devexit_p(ad7887_remove),
+ .id_table = ad7887_id,
+};
+module_spi_driver(ad7887_driver);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD7887 ADC");
+MODULE_LICENSE("GPL v2");