help
Say yes here to include ring buffer support in the AD799X
ADC driver.
+
+config AD7476
+ tristate "Analog Devices AD7475/6/7/8 AD7466/7/8 and AD7495 ADC driver"
+ depends on SPI
+ help
+ Say yes here to build support for Analog Devices AD7475/6/7/8,
+ AD7466/7/8 and AD7495 ADC driver.
+ If unsure, say N (but it's safe to say "Y").
+
+ To compile this driver as a module, choose M here: the
+ module will be called ad7476.
ad799x-y := ad799x_core.o
ad799x-$(CONFIG_AD799X_RING_BUFFER) += ad799x_ring.o
obj-$(CONFIG_AD799X) += ad799x.o
+
+ad7476-y := ad7476_core.o
+ad7476-$(CONFIG_IIO_RING_BUFFER) += ad7476_ring.o
+obj-$(CONFIG_AD7476) += ad7476.o
--- /dev/null
+/*
+ * AD7476/5/7/8 (A) SPI ADC driver
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+#ifndef IIO_ADC_AD7476_H_
+#define IIO_ADC_AD7476_H_
+
+#define RES_MASK(bits) ((1 << (bits)) - 1)
+
+/*
+ * TODO: struct ad7476_platform_data needs to go into include/linux/iio
+ */
+
+struct ad7476_platform_data {
+ u16 vref_mv;
+};
+
+struct ad7476_chip_info {
+ u8 bits;
+ u8 storagebits;
+ u8 res_shift;
+ char sign;
+ u16 int_vref_mv;
+};
+
+struct ad7476_state {
+ struct iio_dev *indio_dev;
+ struct spi_device *spi;
+ const struct ad7476_chip_info *chip_info;
+ struct regulator *reg;
+ struct work_struct poll_work;
+ atomic_t protect_ring;
+ u16 int_vref_mv;
+ struct spi_transfer xfer;
+ struct spi_message msg;
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ */
+ unsigned char data[2] ____cacheline_aligned;
+};
+
+enum ad7476_supported_device_ids {
+ ID_AD7466,
+ ID_AD7467,
+ ID_AD7468,
+ ID_AD7475,
+ ID_AD7476,
+ ID_AD7477,
+ ID_AD7478,
+ ID_AD7495
+};
+
+#ifdef CONFIG_IIO_RING_BUFFER
+int ad7476_scan_from_ring(struct ad7476_state *st);
+int ad7476_register_ring_funcs_and_init(struct iio_dev *indio_dev);
+void ad7476_ring_cleanup(struct iio_dev *indio_dev);
+#else /* CONFIG_IIO_RING_BUFFER */
+static inline ssize_t ad7476_scan_from_ring(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return 0;
+}
+
+static inline int
+ad7476_register_ring_funcs_and_init(struct iio_dev *indio_dev)
+{
+ return 0;
+}
+
+static inline void ad7476_ring_cleanup(struct iio_dev *indio_dev)
+{
+}
+#endif /* CONFIG_IIO_RING_BUFFER */
+#endif /* IIO_ADC_AD7476_H_ */
--- /dev/null
+/*
+ * AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/list.h>
+#include <linux/spi/spi.h>
+#include <linux/regulator/consumer.h>
+#include <linux/err.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+#include "../ring_generic.h"
+#include "adc.h"
+
+#include "ad7476.h"
+
+static int ad7476_scan_direct(struct ad7476_state *st)
+{
+ struct spi_device *spi = st->spi;
+ int ret;
+
+ ret = spi_sync(spi, &st->msg);
+ if (ret)
+ return ret;
+
+ return (st->data[0] << 8) | st->data[1];
+}
+
+static ssize_t ad7476_scan(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7476_state *st = dev_info->dev_data;
+ int ret;
+
+ mutex_lock(&dev_info->mlock);
+ if (iio_ring_enabled(dev_info))
+ ret = ad7476_scan_from_ring(st);
+ else
+ ret = ad7476_scan_direct(st);
+ mutex_unlock(&dev_info->mlock);
+
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", (ret >> st->chip_info->res_shift) &
+ RES_MASK(st->chip_info->bits));
+}
+static IIO_DEV_ATTR_IN_RAW(0, ad7476_scan, 0);
+
+static ssize_t ad7476_show_scale(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ /* Driver currently only support internal vref */
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7476_state *st = iio_dev_get_devdata(dev_info);
+ /* Corresponds to Vref / 2^(bits) */
+
+ if ((1 << (st->chip_info->bits + 1)) > st->int_vref_mv)
+ return sprintf(buf, "%d/2^%d\n",
+ st->int_vref_mv, st->chip_info->bits);
+ else
+ return sprintf(buf, "%d\n",
+ st->int_vref_mv >> st->chip_info->bits);
+}
+static IIO_DEVICE_ATTR(in_scale, S_IRUGO, ad7476_show_scale, NULL, 0);
+
+static ssize_t ad7476_show_name(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7476_state *st = iio_dev_get_devdata(dev_info);
+
+ return sprintf(buf, "%s\n", spi_get_device_id(st->spi)->name);
+}
+static IIO_DEVICE_ATTR(name, S_IRUGO, ad7476_show_name, NULL, 0);
+
+static struct attribute *ad7476_attributes[] = {
+ &iio_dev_attr_in0_raw.dev_attr.attr,
+ &iio_dev_attr_in_scale.dev_attr.attr,
+ &iio_dev_attr_name.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ad7476_attribute_group = {
+ .attrs = ad7476_attributes,
+};
+
+static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
+ [ID_AD7466] = {
+ .bits = 12,
+ .storagebits = 16,
+ .res_shift = 0,
+ .sign = IIO_SCAN_EL_TYPE_UNSIGNED,
+ },
+ [ID_AD7467] = {
+ .bits = 10,
+ .storagebits = 16,
+ .res_shift = 2,
+ .sign = IIO_SCAN_EL_TYPE_UNSIGNED,
+ },
+ [ID_AD7468] = {
+ .bits = 8,
+ .storagebits = 16,
+ .res_shift = 4,
+ .sign = IIO_SCAN_EL_TYPE_UNSIGNED,
+ },
+ [ID_AD7475] = {
+ .bits = 12,
+ .storagebits = 16,
+ .res_shift = 0,
+ .sign = IIO_SCAN_EL_TYPE_UNSIGNED,
+ },
+ [ID_AD7476] = {
+ .bits = 12,
+ .storagebits = 16,
+ .res_shift = 0,
+ .sign = IIO_SCAN_EL_TYPE_UNSIGNED,
+ },
+ [ID_AD7477] = {
+ .bits = 10,
+ .storagebits = 16,
+ .res_shift = 2,
+ .sign = IIO_SCAN_EL_TYPE_UNSIGNED,
+ },
+ [ID_AD7478] = {
+ .bits = 8,
+ .storagebits = 16,
+ .res_shift = 4,
+ .sign = IIO_SCAN_EL_TYPE_UNSIGNED,
+ },
+ [ID_AD7495] = {
+ .bits = 12,
+ .storagebits = 16,
+ .res_shift = 0,
+ .int_vref_mv = 2500,
+ .sign = IIO_SCAN_EL_TYPE_UNSIGNED,
+ },
+};
+
+static int __devinit ad7476_probe(struct spi_device *spi)
+{
+ struct ad7476_platform_data *pdata = spi->dev.platform_data;
+ struct ad7476_state *st;
+ int ret, voltage_uv = 0;
+
+ st = kzalloc(sizeof(*st), GFP_KERNEL);
+ if (st == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+
+ st->reg = regulator_get(&spi->dev, "vcc");
+ if (!IS_ERR(st->reg)) {
+ ret = regulator_enable(st->reg);
+ if (ret)
+ goto error_put_reg;
+
+ voltage_uv = regulator_get_voltage(st->reg);
+ }
+
+ st->chip_info =
+ &ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+
+ if (st->chip_info->int_vref_mv)
+ st->int_vref_mv = st->chip_info->int_vref_mv;
+ else if (pdata && pdata->vref_mv)
+ st->int_vref_mv = pdata->vref_mv;
+ else if (voltage_uv)
+ st->int_vref_mv = voltage_uv / 1000;
+ else
+ dev_warn(&spi->dev, "reference voltage unspecified\n");
+
+ spi_set_drvdata(spi, st);
+
+ atomic_set(&st->protect_ring, 0);
+ st->spi = spi;
+
+ st->indio_dev = iio_allocate_device();
+ if (st->indio_dev == NULL) {
+ ret = -ENOMEM;
+ goto error_disable_reg;
+ }
+
+ /* Estabilish that the iio_dev is a child of the i2c device */
+ st->indio_dev->dev.parent = &spi->dev;
+ st->indio_dev->attrs = &ad7476_attribute_group;
+ st->indio_dev->dev_data = (void *)(st);
+ st->indio_dev->driver_module = THIS_MODULE;
+ st->indio_dev->modes = INDIO_DIRECT_MODE;
+
+ /* Setup default message */
+
+ st->xfer.rx_buf = &st->data;
+ st->xfer.len = st->chip_info->storagebits / 8;
+
+ spi_message_init(&st->msg);
+ spi_message_add_tail(&st->xfer, &st->msg);
+
+ ret = ad7476_register_ring_funcs_and_init(st->indio_dev);
+ if (ret)
+ goto error_free_device;
+
+ ret = iio_device_register(st->indio_dev);
+ if (ret)
+ goto error_free_device;
+
+ ret = iio_ring_buffer_register(st->indio_dev->ring, 0);
+ if (ret)
+ goto error_cleanup_ring;
+ return 0;
+
+error_cleanup_ring:
+ ad7476_ring_cleanup(st->indio_dev);
+ iio_device_unregister(st->indio_dev);
+error_free_device:
+ iio_free_device(st->indio_dev);
+error_disable_reg:
+ if (!IS_ERR(st->reg))
+ regulator_disable(st->reg);
+error_put_reg:
+ if (!IS_ERR(st->reg))
+ regulator_put(st->reg);
+ kfree(st);
+error_ret:
+ return ret;
+}
+
+static int ad7476_remove(struct spi_device *spi)
+{
+ struct ad7476_state *st = spi_get_drvdata(spi);
+ struct iio_dev *indio_dev = st->indio_dev;
+ iio_ring_buffer_unregister(indio_dev->ring);
+ ad7476_ring_cleanup(indio_dev);
+ iio_device_unregister(indio_dev);
+ if (!IS_ERR(st->reg)) {
+ regulator_disable(st->reg);
+ regulator_put(st->reg);
+ }
+ kfree(st);
+ return 0;
+}
+
+static const struct spi_device_id ad7476_id[] = {
+ {"ad7466", ID_AD7466},
+ {"ad7467", ID_AD7467},
+ {"ad7468", ID_AD7468},
+ {"ad7475", ID_AD7475},
+ {"ad7476", ID_AD7476},
+ {"ad7476a", ID_AD7476},
+ {"ad7477", ID_AD7477},
+ {"ad7477a", ID_AD7477},
+ {"ad7478", ID_AD7478},
+ {"ad7478a", ID_AD7478},
+ {"ad7495", ID_AD7495},
+ {}
+};
+
+static struct spi_driver ad7476_driver = {
+ .driver = {
+ .name = "ad7476",
+ .bus = &spi_bus_type,
+ .owner = THIS_MODULE,
+ },
+ .probe = ad7476_probe,
+ .remove = __devexit_p(ad7476_remove),
+ .id_table = ad7476_id,
+};
+
+static int __init ad7476_init(void)
+{
+ return spi_register_driver(&ad7476_driver);
+}
+module_init(ad7476_init);
+
+static void __exit ad7476_exit(void)
+{
+ spi_unregister_driver(&ad7476_driver);
+}
+module_exit(ad7476_exit);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD7475/6/7/8(A) AD7466/7/8 ADC");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("spi:ad7476");
--- /dev/null
+/*
+ * Copyright 2010 Analog Devices Inc.
+ * Copyright (C) 2008 Jonathan Cameron
+ *
+ * Licensed under the GPL-2 or later.
+ *
+ * ad7476_ring.c
+ */
+
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <linux/workqueue.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/list.h>
+#include <linux/spi/spi.h>
+
+#include "../iio.h"
+#include "../ring_generic.h"
+#include "../ring_sw.h"
+#include "../trigger.h"
+#include "../sysfs.h"
+
+#include "ad7476.h"
+
+static IIO_SCAN_EL_C(in0, 0, 0, NULL);
+
+static ssize_t ad7476_show_type(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_ring_buffer *ring = dev_get_drvdata(dev);
+ struct iio_dev *indio_dev = ring->indio_dev;
+ struct ad7476_state *st = indio_dev->dev_data;
+
+ return sprintf(buf, "%c%d/%d>>%d\n", st->chip_info->sign,
+ st->chip_info->bits, st->chip_info->storagebits,
+ st->chip_info->res_shift);
+}
+static IIO_DEVICE_ATTR(in_type, S_IRUGO, ad7476_show_type, NULL, 0);
+
+static struct attribute *ad7476_scan_el_attrs[] = {
+ &iio_scan_el_in0.dev_attr.attr,
+ &iio_const_attr_in0_index.dev_attr.attr,
+ &iio_dev_attr_in_type.dev_attr.attr,
+ NULL,
+};
+
+static struct attribute_group ad7476_scan_el_group = {
+ .name = "scan_elements",
+ .attrs = ad7476_scan_el_attrs,
+};
+
+int ad7476_scan_from_ring(struct ad7476_state *st)
+{
+ struct iio_ring_buffer *ring = st->indio_dev->ring;
+ int ret;
+ u8 *ring_data;
+
+ ring_data = kmalloc(ring->access.get_bytes_per_datum(ring), GFP_KERNEL);
+ if (ring_data == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+ ret = ring->access.read_last(ring, ring_data);
+ if (ret)
+ goto error_free_ring_data;
+
+ ret = (ring_data[0] << 8) | ring_data[1];
+
+error_free_ring_data:
+ kfree(ring_data);
+error_ret:
+ return ret;
+}
+
+/**
+ * ad7476_ring_preenable() setup the parameters of the ring before enabling
+ *
+ * The complex nature of the setting of the nuber of bytes per datum is due
+ * to this driver currently ensuring that the timestamp is stored at an 8
+ * byte boundary.
+ **/
+static int ad7476_ring_preenable(struct iio_dev *indio_dev)
+{
+ struct ad7476_state *st = indio_dev->dev_data;
+ size_t d_size;
+
+ if (indio_dev->ring->access.set_bytes_per_datum) {
+ d_size = st->chip_info->storagebits / 8 + sizeof(s64);
+ if (d_size % 8)
+ d_size += 8 - (d_size % 8);
+ indio_dev->ring->access.set_bytes_per_datum(indio_dev->ring,
+ d_size);
+ }
+
+ return 0;
+}
+
+/**
+ * ad7476_poll_func_th() th of trigger launched polling to ring buffer
+ *
+ * As sampling only occurs on i2c comms occuring, leave timestamping until
+ * then. Some triggers will generate their own time stamp. Currently
+ * there is no way of notifying them when no one cares.
+ **/
+static void ad7476_poll_func_th(struct iio_dev *indio_dev, s64 time)
+{
+ struct ad7476_state *st = indio_dev->dev_data;
+
+ schedule_work(&st->poll_work);
+ return;
+}
+/**
+ * ad7476_poll_bh_to_ring() bh of trigger launched polling to ring buffer
+ * @work_s: the work struct through which this was scheduled
+ *
+ * Currently there is no option in this driver to disable the saving of
+ * timestamps within the ring.
+ * I think the one copy of this at a time was to avoid problems if the
+ * trigger was set far too high and the reads then locked up the computer.
+ **/
+static void ad7476_poll_bh_to_ring(struct work_struct *work_s)
+{
+ struct ad7476_state *st = container_of(work_s, struct ad7476_state,
+ poll_work);
+ struct iio_dev *indio_dev = st->indio_dev;
+ struct iio_sw_ring_buffer *sw_ring = iio_to_sw_ring(indio_dev->ring);
+ s64 time_ns;
+ __u8 *rxbuf;
+ int b_sent;
+ size_t d_size;
+
+ /* Ensure the timestamp is 8 byte aligned */
+ d_size = st->chip_info->storagebits / 8 + sizeof(s64);
+ if (d_size % sizeof(s64))
+ d_size += sizeof(s64) - (d_size % sizeof(s64));
+
+ /* Ensure only one copy of this function running at a time */
+ if (atomic_inc_return(&st->protect_ring) > 1)
+ return;
+
+ rxbuf = kzalloc(d_size, GFP_KERNEL);
+ if (rxbuf == NULL)
+ return;
+
+ b_sent = spi_read(st->spi, rxbuf, st->chip_info->storagebits / 8);
+ if (b_sent < 0)
+ goto done;
+
+ time_ns = iio_get_time_ns();
+
+ memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));
+
+ indio_dev->ring->access.store_to(&sw_ring->buf, rxbuf, time_ns);
+done:
+ kfree(rxbuf);
+ atomic_dec(&st->protect_ring);
+}
+
+int ad7476_register_ring_funcs_and_init(struct iio_dev *indio_dev)
+{
+ struct ad7476_state *st = indio_dev->dev_data;
+ int ret = 0;
+
+ indio_dev->ring = iio_sw_rb_allocate(indio_dev);
+ if (!indio_dev->ring) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+ /* Effectively select the ring buffer implementation */
+ iio_ring_sw_register_funcs(&indio_dev->ring->access);
+ ret = iio_alloc_pollfunc(indio_dev, NULL, &ad7476_poll_func_th);
+ if (ret)
+ goto error_deallocate_sw_rb;
+
+ /* Ring buffer functions - here trigger setup related */
+
+ indio_dev->ring->preenable = &ad7476_ring_preenable;
+ indio_dev->ring->postenable = &iio_triggered_ring_postenable;
+ indio_dev->ring->predisable = &iio_triggered_ring_predisable;
+ indio_dev->ring->scan_el_attrs = &ad7476_scan_el_group;
+
+ INIT_WORK(&st->poll_work, &ad7476_poll_bh_to_ring);
+
+ /* Flag that polled ring buffering is possible */
+ indio_dev->modes |= INDIO_RING_TRIGGERED;
+ return 0;
+error_deallocate_sw_rb:
+ iio_sw_rb_free(indio_dev->ring);
+error_ret:
+ return ret;
+}
+
+void ad7476_ring_cleanup(struct iio_dev *indio_dev)
+{
+ /* ensure that the trigger has been detached */
+ if (indio_dev->trig) {
+ iio_put_trigger(indio_dev->trig);
+ iio_trigger_dettach_poll_func(indio_dev->trig,
+ indio_dev->pollfunc);
+ }
+ kfree(indio_dev->pollfunc);
+ iio_sw_rb_free(indio_dev->ring);
+}
projects / platform / upstream / kernel-adaptation-pc.git / commitdiff