On 5/9/2012 11:36 AM, michael.hennerich@xxxxxxxxxx wrote:
From: Michael Hennerich<michael.hennerich@xxxxxxxxxx>
Changes since V1:
Apply review feedback:
Introduce and use IIO_CHAN_INFO_HARDWAREGAIN
Introduce and use Use IIO_VAL_INT_PLUS_MICRO_DB
Modify out of staging include paths.
Convert to new iio core API naming.
For reasons I don't understand thunderbird on windows (yes I'm doing
this whilst waiting for something to run at the day job), is wrecking
spacing in subtle ways despite being in plain text mode... Grr.
Anyhow, my only real comment is that I think we may want a little more
value sanity checking in the write_raw function. Not critical as
hopefully no one will write anything stupid to that, but nice to lock
down anyway if you have the time.
Signed-off-by: Michael Hennerich<michael.hennerich@xxxxxxxxxx>
Acked-by: Jonathan Cameron <jic23@xxxxxxxxxx>
---
drivers/staging/iio/Kconfig | 1 +
drivers/staging/iio/Makefile | 1 +
drivers/staging/iio/amplifiers/Kconfig | 17 +++
drivers/staging/iio/amplifiers/Makefile | 5 +
drivers/staging/iio/amplifiers/ad8366.c | 219 +++++++++++++++++++++++++++++++
5 files changed, 243 insertions(+), 0 deletions(-)
create mode 100644 drivers/staging/iio/amplifiers/Kconfig
create mode 100644 drivers/staging/iio/amplifiers/Makefile
create mode 100644 drivers/staging/iio/amplifiers/ad8366.c
diff --git a/drivers/staging/iio/Kconfig b/drivers/staging/iio/Kconfig
index 3c8e5ec..10c899b 100644
--- a/drivers/staging/iio/Kconfig
+++ b/drivers/staging/iio/Kconfig
@@ -28,6 +28,7 @@ endif # IIO_BUFFER
source "drivers/staging/iio/accel/Kconfig"
source "drivers/staging/iio/adc/Kconfig"
source "drivers/staging/iio/addac/Kconfig"
+source "drivers/staging/iio/amplifiers/Kconfig"
source "drivers/staging/iio/cdc/Kconfig"
source "drivers/staging/iio/dac/Kconfig"
source "drivers/staging/iio/frequency/Kconfig"
diff --git a/drivers/staging/iio/Makefile b/drivers/staging/iio/Makefile
index 6a46d5a..8e18228 100644
--- a/drivers/staging/iio/Makefile
+++ b/drivers/staging/iio/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_IIO_ST_HWMON) += iio_hwmon.o
obj-y += accel/
obj-y += adc/
obj-y += addac/
+obj-y += amplifiers/
obj-y += cdc/
obj-y += dac/
obj-y += frequency/
diff --git a/drivers/staging/iio/amplifiers/Kconfig b/drivers/staging/iio/amplifiers/Kconfig
new file mode 100644
index 0000000..05d707e
--- /dev/null
+++ b/drivers/staging/iio/amplifiers/Kconfig
@@ -0,0 +1,17 @@
+#
+# Gain Amplifiers, etc.
+#
+menu "Amplifiers"
+
+config AD8366
+ tristate "Analog Devices AD8366 VGA"
+ depends on SPI
+ select BITREVERSE
+ help
+ Say yes here to build support for Analog Devices AD8366
+ SPI Dual-Digital Variable Gain Amplifier (VGA).
+
+ To compile this driver as a module, choose M here: the
+ module will be called ad8366.
+
+endmenu
diff --git a/drivers/staging/iio/amplifiers/Makefile b/drivers/staging/iio/amplifiers/Makefile
new file mode 100644
index 0000000..a6ca366
--- /dev/null
+++ b/drivers/staging/iio/amplifiers/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile iio/amplifiers
+#
+
+obj-$(CONFIG_AD8366) += ad8366.o
diff --git a/drivers/staging/iio/amplifiers/ad8366.c b/drivers/staging/iio/amplifiers/ad8366.c
new file mode 100644
index 0000000..9067750
--- /dev/null
+++ b/drivers/staging/iio/amplifiers/ad8366.c
@@ -0,0 +1,219 @@
+/*
+ * AD8366 SPI Dual-Digital Variable Gain Amplifier (VGA)
+ *
+ * Copyright 2012 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/bitrev.h>
+
+#include<linux/iio/iio.h>
+#include<linux/iio/sysfs.h>
+
+struct ad8366_state {
+ struct spi_device *spi;
+ struct regulator *reg;
+ unsigned char ch[2];
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ */
+ unsigned char data[2] ____cacheline_aligned;
+};
+
+static int ad8366_write(struct iio_dev *indio_dev,
+ unsigned char ch_a, char unsigned ch_b)
+{
+ struct ad8366_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ch_a = bitrev8(ch_a& 0x3F);
+ ch_b = bitrev8(ch_b& 0x3F);
+
+ st->data[0] = ch_b>> 4;
+ st->data[1] = (ch_b<< 4) | (ch_a>> 2);
+
+ ret = spi_write(st->spi, st->data, ARRAY_SIZE(st->data));
+ if (ret< 0)
+ dev_err(&indio_dev->dev, "write failed (%d)", ret);
+
+ return ret;
+}
+
+static int ad8366_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long m)
+{
+ struct ad8366_state *st = iio_priv(indio_dev);
+ int ret;
+ unsigned code;
+
+ mutex_lock(&indio_dev->mlock);
+ switch (m) {
+ case IIO_CHAN_INFO_HARDWAREGAIN:
+ code = st->ch[chan->channel];
+
+ /* Values in dB */
+ code = code * 253 + 4500;
+ *val = code / 1000;
+ *val2 = (code % 1000) * 1000;
+
+ ret = IIO_VAL_INT_PLUS_MICRO_DB;
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret;
+};
+
+static int ad8366_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val,
+ int val2,
+ long mask)
+{
+ struct ad8366_state *st = iio_priv(indio_dev);
+ unsigned code;
+ int ret;
+
+ /* Values in dB */
This could do some rather unpredictable things if for whatever
reason val2 is negative. Might be worth doing a little more sanity checking?
+ code = (((u8)val * 1000) + ((u32)val2 / 1000));
+
+ if (code> 20500 || code< 4500)
+ return -EINVAL;
+
+ code = (code - 4500) / 253;
+
+ mutex_lock(&indio_dev->mlock);
+ switch (mask) {
+ case IIO_CHAN_INFO_HARDWAREGAIN:
+ st->ch[chan->channel] = code;
+ ret = ad8366_write(indio_dev, st->ch[0], st->ch[1]);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ mutex_unlock(&indio_dev->mlock);
+
+ return ret;
+}
+
+static const struct iio_info ad8366_info = {
+ .read_raw =&ad8366_read_raw,
+ .write_raw =&ad8366_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+#define AD8366_CHAN(_channel) { \
+ .type = IIO_VOLTAGE, \
+ .output = 1, \
+ .indexed = 1, \
+ .channel = _channel, \
+ .info_mask = IIO_CHAN_INFO_HARDWAREGAIN_SEPARATE_BIT,\
+}
+
+static const struct iio_chan_spec ad8366_channels[] = {
+ AD8366_CHAN(0),
+ AD8366_CHAN(1),
+};
+
+static int __devinit ad8366_probe(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev;
+ struct ad8366_state *st;
+ int ret;
+
+ indio_dev = iio_device_alloc(sizeof(*st));
+ if (indio_dev == NULL)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+
+ st->reg = regulator_get(&spi->dev, "vcc");
+ if (!IS_ERR(st->reg)) {
+ ret = regulator_enable(st->reg);
+ if (ret)
+ goto error_put_reg;
+ }
+
+ spi_set_drvdata(spi, indio_dev);
+ st->spi = spi;
+
+ indio_dev->dev.parent =&spi->dev;
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->info =&ad8366_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = ad8366_channels;
+ indio_dev->num_channels = ARRAY_SIZE(ad8366_channels);
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error_disable_reg;
+
+ ad8366_write(indio_dev, 0 , 0);
+
+ return 0;
+
+error_disable_reg:
+ if (!IS_ERR(st->reg))
+ regulator_disable(st->reg);
+error_put_reg:
+ if (!IS_ERR(st->reg))
+ regulator_put(st->reg);
+
+ iio_device_free(indio_dev);
+
+ return ret;
+}
+
+static int __devexit ad8366_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct ad8366_state *st = iio_priv(indio_dev);
+ struct regulator *reg = st->reg;
+
+ iio_device_unregister(indio_dev);
+
+ if (!IS_ERR(reg)) {
+ regulator_disable(reg);
+ regulator_put(reg);
+ }
+
+ iio_device_free(indio_dev);
+
+ return 0;
+}
+
+static const struct spi_device_id ad8366_id[] = {
+ {"ad8366", 0},
+ {}
+};
+
+static struct spi_driver ad8366_driver = {
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .owner = THIS_MODULE,
+ },
+ .probe = ad8366_probe,
+ .remove = __devexit_p(ad8366_remove),
+ .id_table = ad8366_id,
+};
+
+module_spi_driver(ad8366_driver);
+
+MODULE_AUTHOR("Michael Hennerich<hennerich@xxxxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Analog Devices AD8366 VGA");
+MODULE_LICENSE("GPL v2");
--
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