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authorLinus Torvalds <torvalds@linux-foundation.org>2012-07-26 18:14:49 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-26 18:14:49 (GMT)
commitb13bc8dda81c54a66a1c84e66f60b8feba659f28 (patch)
tree100a26eada424fa5d9b0e5eaaf4e23b8fa036fc8 /drivers/iio/dac/mcp4725.c
parent9fc377799bc9bfd8d5cb35d0d1ea2e2458cbdbb3 (diff)
parent419e9266884fa853179ab726c27a63a9d3ae46e3 (diff)
downloadlinux-fsl-qoriq-b13bc8dda81c54a66a1c84e66f60b8feba659f28.tar.xz
Merge tag 'staging-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging tree patches from Greg Kroah-Hartman: "Here's the big staging tree merge for the 3.6-rc1 merge window. There are some patches in here outside of drivers/staging/, notibly the iio code (which is still stradeling the staging / not staging boundry), the pstore code, and the tracing code. All of these have gotten acks from the various subsystem maintainers to be included in this tree. The pstore and tracing patches are related, and are coming here as they replace one of the android staging drivers. Otherwise, the normal staging mess. Lots of cleanups and a few new drivers (some iio drivers, and the large csr wireless driver abomination.) Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" Fixed up trivial conflicts in drivers/staging/comedi/drivers/s626.h and drivers/staging/gdm72xx/netlink_k.c * tag 'staging-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1108 commits) staging: csr: delete a bunch of unused library functions staging: csr: remove csr_utf16.c staging: csr: remove csr_pmem.h staging: csr: remove CsrPmemAlloc staging: csr: remove CsrPmemFree() staging: csr: remove CsrMemAllocDma() staging: csr: remove CsrMemCalloc() staging: csr: remove CsrMemAlloc() staging: csr: remove CsrMemFree() and CsrMemFreeDma() staging: csr: remove csr_util.h staging: csr: remove CsrOffSetOf() stating: csr: remove unneeded #includes in csr_util.c staging: csr: make CsrUInt16ToHex static staging: csr: remove CsrMemCpy() staging: csr: remove CsrStrLen() staging: csr: remove CsrVsnprintf() staging: csr: remove CsrStrDup staging: csr: remove CsrStrChr() staging: csr: remove CsrStrNCmp staging: csr: remove CsrStrCmp ...
Diffstat (limited to 'drivers/iio/dac/mcp4725.c')
-rw-r--r--drivers/iio/dac/mcp4725.c227
1 files changed, 227 insertions, 0 deletions
diff --git a/drivers/iio/dac/mcp4725.c b/drivers/iio/dac/mcp4725.c
new file mode 100644
index 0000000..e0e168b
--- /dev/null
+++ b/drivers/iio/dac/mcp4725.c
@@ -0,0 +1,227 @@
+/*
+ * mcp4725.c - Support for Microchip MCP4725
+ *
+ * Copyright (C) 2012 Peter Meerwald <pmeerw@pmeerw.net>
+ *
+ * Based on max517 by Roland Stigge <stigge@antcom.de>
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * driver for the Microchip I2C 12-bit digital-to-analog converter (DAC)
+ * (7-bit I2C slave address 0x60, the three LSBs can be configured in
+ * hardware)
+ *
+ * writing the DAC value to EEPROM is not supported
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#include <linux/iio/dac/mcp4725.h>
+
+#define MCP4725_DRV_NAME "mcp4725"
+
+struct mcp4725_data {
+ struct i2c_client *client;
+ u16 vref_mv;
+ u16 dac_value;
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int mcp4725_suspend(struct device *dev)
+{
+ u8 outbuf[2];
+
+ outbuf[0] = 0x3 << 4; /* power-down bits, 500 kOhm resistor */
+ outbuf[1] = 0;
+
+ return i2c_master_send(to_i2c_client(dev), outbuf, 2);
+}
+
+static int mcp4725_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct mcp4725_data *data = iio_priv(indio_dev);
+ u8 outbuf[2];
+
+ /* restore previous DAC value */
+ outbuf[0] = (data->dac_value >> 8) & 0xf;
+ outbuf[1] = data->dac_value & 0xff;
+
+ return i2c_master_send(to_i2c_client(dev), outbuf, 2);
+}
+
+static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume);
+#define MCP4725_PM_OPS (&mcp4725_pm_ops)
+#else
+#define MCP4725_PM_OPS NULL
+#endif
+
+static const struct iio_chan_spec mcp4725_channel = {
+ .type = IIO_VOLTAGE,
+ .indexed = 1,
+ .output = 1,
+ .channel = 0,
+ .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
+ IIO_CHAN_INFO_SCALE_SHARED_BIT,
+ .scan_type = IIO_ST('u', 12, 16, 0),
+};
+
+static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
+{
+ struct mcp4725_data *data = iio_priv(indio_dev);
+ u8 outbuf[2];
+ int ret;
+
+ if (val >= (1 << 12) || val < 0)
+ return -EINVAL;
+
+ outbuf[0] = (val >> 8) & 0xf;
+ outbuf[1] = val & 0xff;
+
+ ret = i2c_master_send(data->client, outbuf, 2);
+ if (ret < 0)
+ return ret;
+ else if (ret != 2)
+ return -EIO;
+ else
+ return 0;
+}
+
+static int mcp4725_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct mcp4725_data *data = iio_priv(indio_dev);
+ unsigned long scale_uv;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ *val = data->dac_value;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ scale_uv = (data->vref_mv * 1000) >> 12;
+ *val = scale_uv / 1000000;
+ *val2 = scale_uv % 1000000;
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+ return -EINVAL;
+}
+
+static int mcp4725_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct mcp4725_data *data = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = mcp4725_set_value(indio_dev, val);
+ data->dac_value = val;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret;
+}
+
+static const struct iio_info mcp4725_info = {
+ .read_raw = mcp4725_read_raw,
+ .write_raw = mcp4725_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static int __devinit mcp4725_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct mcp4725_data *data;
+ struct iio_dev *indio_dev;
+ struct mcp4725_platform_data *platform_data = client->dev.platform_data;
+ u8 inbuf[3];
+ int err;
+
+ if (!platform_data || !platform_data->vref_mv) {
+ dev_err(&client->dev, "invalid platform data");
+ err = -EINVAL;
+ goto exit;
+ }
+
+ indio_dev = iio_device_alloc(sizeof(*data));
+ if (indio_dev == NULL) {
+ err = -ENOMEM;
+ goto exit;
+ }
+ data = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
+ data->client = client;
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = &mcp4725_info;
+ indio_dev->channels = &mcp4725_channel;
+ indio_dev->num_channels = 1;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ data->vref_mv = platform_data->vref_mv;
+
+ /* read current DAC value */
+ err = i2c_master_recv(client, inbuf, 3);
+ if (err < 0) {
+ dev_err(&client->dev, "failed to read DAC value");
+ goto exit_free_device;
+ }
+ data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
+
+ err = iio_device_register(indio_dev);
+ if (err)
+ goto exit_free_device;
+
+ dev_info(&client->dev, "MCP4725 DAC registered\n");
+
+ return 0;
+
+exit_free_device:
+ iio_device_free(indio_dev);
+exit:
+ return err;
+}
+
+static int __devexit mcp4725_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+ iio_device_unregister(indio_dev);
+ iio_device_free(indio_dev);
+
+ return 0;
+}
+
+static const struct i2c_device_id mcp4725_id[] = {
+ { "mcp4725", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, mcp4725_id);
+
+static struct i2c_driver mcp4725_driver = {
+ .driver = {
+ .name = MCP4725_DRV_NAME,
+ .pm = MCP4725_PM_OPS,
+ },
+ .probe = mcp4725_probe,
+ .remove = __devexit_p(mcp4725_remove),
+ .id_table = mcp4725_id,
+};
+module_i2c_driver(mcp4725_driver);
+
+MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
+MODULE_DESCRIPTION("MCP4725 12-bit DAC");
+MODULE_LICENSE("GPL");