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213 lines
4.5 KiB
213 lines
4.5 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* max517.c - Support for Maxim MAX517, MAX518 and MAX519 |
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* |
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* Copyright (C) 2010, 2011 Roland Stigge <[email protected]> |
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*/ |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/jiffies.h> |
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#include <linux/i2c.h> |
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#include <linux/err.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/sysfs.h> |
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#include <linux/iio/dac/max517.h> |
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#define MAX517_DRV_NAME "max517" |
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/* Commands */ |
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#define COMMAND_CHANNEL0 0x00 |
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#define COMMAND_CHANNEL1 0x01 /* for MAX518 and MAX519 */ |
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#define COMMAND_PD 0x08 /* Power Down */ |
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enum max517_device_ids { |
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ID_MAX517, |
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ID_MAX518, |
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ID_MAX519, |
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ID_MAX520, |
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ID_MAX521, |
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}; |
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struct max517_data { |
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struct i2c_client *client; |
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unsigned short vref_mv[8]; |
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}; |
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/* |
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* channel: bit 0: channel 1 |
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* bit 1: channel 2 |
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* (this way, it's possible to set both channels at once) |
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*/ |
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static int max517_set_value(struct iio_dev *indio_dev, |
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long val, int channel) |
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{ |
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struct max517_data *data = iio_priv(indio_dev); |
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struct i2c_client *client = data->client; |
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u8 outbuf[2]; |
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int res; |
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if (val < 0 || val > 255) |
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return -EINVAL; |
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outbuf[0] = channel; |
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outbuf[1] = val; |
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res = i2c_master_send(client, outbuf, 2); |
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if (res < 0) |
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return res; |
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else if (res != 2) |
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return -EIO; |
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else |
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return 0; |
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} |
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static int max517_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, |
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int *val, |
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int *val2, |
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long m) |
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{ |
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struct max517_data *data = iio_priv(indio_dev); |
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switch (m) { |
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case IIO_CHAN_INFO_SCALE: |
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/* Corresponds to Vref / 2^(bits) */ |
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*val = data->vref_mv[chan->channel]; |
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*val2 = 8; |
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return IIO_VAL_FRACTIONAL_LOG2; |
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default: |
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break; |
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} |
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return -EINVAL; |
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} |
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static int max517_write_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, int val, int val2, long mask) |
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{ |
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int ret; |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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ret = max517_set_value(indio_dev, val, chan->channel); |
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break; |
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default: |
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ret = -EINVAL; |
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break; |
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} |
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return ret; |
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} |
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static int __maybe_unused max517_suspend(struct device *dev) |
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{ |
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u8 outbuf = COMMAND_PD; |
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return i2c_master_send(to_i2c_client(dev), &outbuf, 1); |
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} |
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static int __maybe_unused max517_resume(struct device *dev) |
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{ |
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u8 outbuf = 0; |
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return i2c_master_send(to_i2c_client(dev), &outbuf, 1); |
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} |
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static SIMPLE_DEV_PM_OPS(max517_pm_ops, max517_suspend, max517_resume); |
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static const struct iio_info max517_info = { |
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.read_raw = max517_read_raw, |
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.write_raw = max517_write_raw, |
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}; |
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#define MAX517_CHANNEL(chan) { \ |
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.type = IIO_VOLTAGE, \ |
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.indexed = 1, \ |
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.output = 1, \ |
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.channel = (chan), \ |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ |
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BIT(IIO_CHAN_INFO_SCALE), \ |
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} |
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static const struct iio_chan_spec max517_channels[] = { |
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MAX517_CHANNEL(0), |
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MAX517_CHANNEL(1), |
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MAX517_CHANNEL(2), |
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MAX517_CHANNEL(3), |
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MAX517_CHANNEL(4), |
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MAX517_CHANNEL(5), |
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MAX517_CHANNEL(6), |
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MAX517_CHANNEL(7), |
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}; |
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static int max517_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct max517_data *data; |
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struct iio_dev *indio_dev; |
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struct max517_platform_data *platform_data = client->dev.platform_data; |
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int chan; |
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
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if (!indio_dev) |
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return -ENOMEM; |
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data = iio_priv(indio_dev); |
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data->client = client; |
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switch (id->driver_data) { |
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case ID_MAX521: |
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indio_dev->num_channels = 8; |
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break; |
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case ID_MAX520: |
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indio_dev->num_channels = 4; |
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break; |
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case ID_MAX519: |
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case ID_MAX518: |
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indio_dev->num_channels = 2; |
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break; |
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default: /* single channel for MAX517 */ |
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indio_dev->num_channels = 1; |
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break; |
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} |
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indio_dev->channels = max517_channels; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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indio_dev->info = &max517_info; |
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/* |
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* Reference voltage on MAX518 and default is 5V, else take vref_mv |
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* from platform_data |
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*/ |
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for (chan = 0; chan < indio_dev->num_channels; chan++) { |
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if (id->driver_data == ID_MAX518 || !platform_data) |
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data->vref_mv[chan] = 5000; /* mV */ |
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else |
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data->vref_mv[chan] = platform_data->vref_mv[chan]; |
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} |
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return devm_iio_device_register(&client->dev, indio_dev); |
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} |
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static const struct i2c_device_id max517_id[] = { |
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{ "max517", ID_MAX517 }, |
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{ "max518", ID_MAX518 }, |
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{ "max519", ID_MAX519 }, |
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{ "max520", ID_MAX520 }, |
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{ "max521", ID_MAX521 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, max517_id); |
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static struct i2c_driver max517_driver = { |
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.driver = { |
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.name = MAX517_DRV_NAME, |
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.pm = &max517_pm_ops, |
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}, |
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.probe = max517_probe, |
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.id_table = max517_id, |
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}; |
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module_i2c_driver(max517_driver); |
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MODULE_AUTHOR("Roland Stigge <[email protected]>"); |
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MODULE_DESCRIPTION("MAX517/518/519/520/521 8-bit DAC"); |
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MODULE_LICENSE("GPL");
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