Hi, On 03/01/11 23:28, Greg KH wrote: >> I've written a driver for the Maxim MAX517/MAX518/MAX519 1/2-channel >> DAC. See also the branch "max51x" of repository linux-2.6 at >> git.antcom.de (alternatively the patch at >> http://www.rolandstigge.de/dp/download/patches/max51x.patch). >> >> It's currently located in drivers/misc/max51x.c, implemented similarly >> to the other drivers like e.g. ti_dac7512.c. The hwmon maintainer >> pointed me to drivers/staging/iio/. >> >> Is it advisible now to port the driver to drivers/staging/iio or keep it >> in drivers/misc? Where should I forward the code/patch for Linux >> integration? > > It's best to convert to the iio subsystem, as that is the way to go in > the future. > > As for where to send patches for it, send them here, and cc: the iio > developers and me and we will be glad to comment on them and apply them > to the kernel tree for submission to Linus's tree. OK, done. Attaching the patch. (Also available at the above mentioned git repository for merging.) Thanks in advance, Roland BTW: Maybe we should also call it "Analog to digital converters" instead of "Analog to digital convertors", see drivers/staging/iio/adc/Kconfig
Added max51x iio driver Signed-off-by: Roland Stigge <stigge@xxxxxxxxx> diff --git a/drivers/staging/iio/Documentation/dac/max51x b/drivers/staging/iio/Documentation/dac/max51x new file mode 100644 index 0000000..cf61a25 --- /dev/null +++ b/drivers/staging/iio/Documentation/dac/max51x @@ -0,0 +1,38 @@ +Kernel driver max51x +==================== + +Supported chips: + * Maxim MAX517, MAX518, MAX519 + Prefix: 'max51x' + Datasheet: Publicly available at the Maxim website + http://www.maxim-ic.com/ + +Author: + Roland Stigge <stigge@xxxxxxxxx> + +Description +----------- + +The Maxim MAX51x is an 8-bit DAC on the I2C bus. The following table shows the +different feature sets of the variants MAX517, MAX518 and MAX519: + +Feature MAX517 MAX518 MAX519 +-------------------------------------------------------------------------- +One output channel X +Two output channels X X +Simultaneous output updates X X +Supply voltage as reference X +Separate reference input X +Reference input for each DAC X + +Via the iio sysfs interface, there are three attributes available: value_1, +value_2 and value_both. With value_1 and value_2, the current output values of +the DACs can be read back from the driver and written to the device. value_both +can be used to set both output channel values simultaneously. + +With MAX517, only value_1 is available. + +When the operating system goes to a power down state, the Power Down function +of the chip is activated, reducing the supply current to 4uA. + +On power-up, the device is in 0V-output state. diff --git a/drivers/staging/iio/Kconfig b/drivers/staging/iio/Kconfig index ed48815..6fc35ad 100644 --- a/drivers/staging/iio/Kconfig +++ b/drivers/staging/iio/Kconfig @@ -42,6 +42,7 @@ config IIO_TRIGGER source "drivers/staging/iio/accel/Kconfig" source "drivers/staging/iio/adc/Kconfig" +source "drivers/staging/iio/dac/Kconfig" source "drivers/staging/iio/gyro/Kconfig" source "drivers/staging/iio/imu/Kconfig" source "drivers/staging/iio/light/Kconfig" diff --git a/drivers/staging/iio/Makefile b/drivers/staging/iio/Makefile index e909674..8766e07 100644 --- a/drivers/staging/iio/Makefile +++ b/drivers/staging/iio/Makefile @@ -11,6 +11,7 @@ obj-$(CONFIG_IIO_SW_RING) += ring_sw.o obj-y += accel/ obj-y += adc/ +obj-y += dac/ obj-y += gyro/ obj-y += imu/ obj-y += light/ diff --git a/drivers/staging/iio/dac/Kconfig b/drivers/staging/iio/dac/Kconfig new file mode 100644 index 0000000..f2c9c84 --- /dev/null +++ b/drivers/staging/iio/dac/Kconfig @@ -0,0 +1,14 @@ +# +# DAC drivers +# +comment "Digital to analog converters" + +config MAX51X + tristate "Maxim MAX51X DAC driver" + depends on I2C && EXPERIMENTAL + help + If you say yes here you get support for the Maxim chips MAX517, + MAX518 and MAX519 (I2C 8-Bit DACs with rail-to-rail outputs). + + This driver can also be built as a module. If so, the module + will be called max51x. diff --git a/drivers/staging/iio/dac/Makefile b/drivers/staging/iio/dac/Makefile new file mode 100644 index 0000000..3caa871 --- /dev/null +++ b/drivers/staging/iio/dac/Makefile @@ -0,0 +1,5 @@ +# +# Makefile for industrial I/O DAC drivers +# + +obj-$(CONFIG_MAX51X) += max51x.o diff --git a/drivers/staging/iio/dac/max51x.c b/drivers/staging/iio/dac/max51x.c new file mode 100644 index 0000000..6d05428 --- /dev/null +++ b/drivers/staging/iio/dac/max51x.c @@ -0,0 +1,258 @@ +/* + * max51x.c - Support for Maxim MAX517, MAX518 and MAX519 + * + * Copyright (C) 2010 Roland Stigge <stigge@xxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/jiffies.h> +#include <linux/i2c.h> +#include <linux/err.h> + +#include "../iio.h" + +#define MAX51X_DRV_NAME "max51x" + +/* Commands */ +#define COMMAND_CHANNEL0 0x00 +#define COMMAND_CHANNEL1 0x01 /* for MAX518 and MAX519 */ +#define COMMAND_PD 0x08 /* Power Down */ + +struct max51x_data { + u8 values[2]; + struct iio_dev *indio_dev; +}; + +/* + * channel: bit 0: channel 1 + * bit 1: channel 2 + * (this way, it's possible to set both channels at once) + */ +static ssize_t max51x_set_value(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count, int channel) +{ + struct i2c_client *client = to_i2c_client(dev); + struct max51x_data *data = i2c_get_clientdata(client); + u8 outbuf[4]; /* 1x or 2x command + value */ + int outbuf_size = 0; + int res; + long val; + + res = strict_strtol(buf, 10, &val); + + if (res) + return res; + + if (val < 0 || val > 255) + return -EINVAL; + + if (channel & 1) { + data->values[0] = val; + outbuf[outbuf_size++] = COMMAND_CHANNEL0; + outbuf[outbuf_size++] = val; + } + if (channel & 2) { + data->values[1] = val; + outbuf[outbuf_size++] = COMMAND_CHANNEL1; + outbuf[outbuf_size++] = val; + } + + /* + * at this point, there are always 1 or 2 two-byte commands in + * outbuf + */ + i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_WRITE, outbuf[0], outbuf_size - 1, + (union i2c_smbus_data *) &outbuf[1]); + return count; +} + +static ssize_t max51x_set_value_1(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + return max51x_set_value(dev, attr, buf, count, 1); +} + +static ssize_t max51x_set_value_2(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + return max51x_set_value(dev, attr, buf, count, 2); +} + +static ssize_t max51x_set_value_both(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + return max51x_set_value(dev, attr, buf, count, 3); +} + +static ssize_t max51x_get_value(struct device *dev, struct device_attribute *da, + char *buf, int channel) +{ + struct i2c_client *client = to_i2c_client(dev); + struct max51x_data *data = i2c_get_clientdata(client); + u8 val; + + if (channel == 1) { + val = data->values[0]; + } else { /* channel == 2 */ + val = data->values[1]; + } + + return sprintf(buf, "%d\n", val); +} + +static ssize_t max51x_get_value_1(struct device *dev, + struct device_attribute *da, char *buf) +{ + return max51x_get_value(dev, da, buf, 1); +} + +static ssize_t max51x_get_value_2(struct device *dev, + struct device_attribute *da, char *buf) +{ + return max51x_get_value(dev, da, buf, 2); +} + +static IIO_DEVICE_ATTR(value_1, S_IWUSR | S_IRUGO, + max51x_get_value_1, max51x_set_value_1, 0); +static IIO_DEVICE_ATTR(value_2, S_IWUSR | S_IRUGO, + max51x_get_value_2, max51x_set_value_2, 1); +static IIO_DEVICE_ATTR(value_both, S_IWUSR, NULL, max51x_set_value_both, -1); + +static struct attribute *max51x_attributes[] = { + &iio_dev_attr_value_1.dev_attr.attr, + &iio_dev_attr_value_2.dev_attr.attr, + &iio_dev_attr_value_both.dev_attr.attr, + NULL +}; + +static struct attribute *max517_attributes[] = { + &iio_dev_attr_value_1.dev_attr.attr, + NULL +}; + +static struct attribute_group max51x_attribute_group = { + .attrs = max51x_attributes, +}; + +static int max51x_suspend(struct i2c_client *client, pm_message_t mesg) +{ + return i2c_smbus_write_byte(client, COMMAND_PD); +} + +static int max51x_resume(struct i2c_client *client) +{ + return i2c_smbus_write_byte(client, 0); +} + +static int max51x_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct max51x_data *data; + int err; + + data = kzalloc(sizeof(struct max51x_data), GFP_KERNEL); + if (!data) { + err = -ENOMEM; + goto exit; + } + + i2c_set_clientdata(client, data); + + /* reduced attribute set for max517 */ + if (!strcmp(id->name, "max517")) + max51x_attribute_group.attrs = max517_attributes; + + data->indio_dev = iio_allocate_device(); + if (data->indio_dev == NULL) { + err = -ENOMEM; + goto exit_free_data; + } + + /* establish that the iio_dev is a child of the i2c device */ + data->indio_dev->dev.parent = &client->dev; + data->indio_dev->attrs = &max51x_attribute_group; + data->indio_dev->dev_data = (void *)(data); + data->indio_dev->driver_module = THIS_MODULE; + data->indio_dev->modes = INDIO_DIRECT_MODE; + + err = iio_device_register(data->indio_dev); + if (err) + goto exit_free_device; + + dev_info(&client->dev, "DAC registered\n"); + + return 0; + +exit_free_device: + iio_free_device(data->indio_dev); +exit_free_data: + kfree(data); +exit: + return err; +} + +static int max51x_remove(struct i2c_client *client) +{ + struct max51x_data *data = i2c_get_clientdata(client); + + kfree(data); + + return 0; +} + +static const struct i2c_device_id max51x_id[] = { + { "max517", 0 }, + { "max518", 0 }, + { "max519", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, max51x_id); + +static struct i2c_driver max51x_driver = { + .driver = { + .name = MAX51X_DRV_NAME, + }, + .probe = max51x_probe, + .remove = max51x_remove, + .suspend = max51x_suspend, + .resume = max51x_resume, + .id_table = max51x_id, +}; + +static int __init max51x_init(void) +{ + return i2c_add_driver(&max51x_driver); +} + +static void __exit max51x_exit(void) +{ + i2c_del_driver(&max51x_driver); +} + +MODULE_AUTHOR("Roland Stigge <stigge@xxxxxxxxx>"); +MODULE_DESCRIPTION("MAX51X 8-bit DAC"); +MODULE_LICENSE("GPL"); + +module_init(max51x_init); +module_exit(max51x_exit);
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