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396 lines
9.1 KiB
396 lines
9.1 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* iio/dac/max5821.c |
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* Copyright (C) 2014 Philippe Reynes |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/i2c.h> |
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#include <linux/iio/iio.h> |
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#include <linux/regulator/consumer.h> |
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#define MAX5821_MAX_DAC_CHANNELS 2 |
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/* command bytes */ |
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#define MAX5821_LOAD_DAC_A_IN_REG_B 0x00 |
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#define MAX5821_LOAD_DAC_B_IN_REG_A 0x10 |
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#define MAX5821_EXTENDED_COMMAND_MODE 0xf0 |
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#define MAX5821_READ_DAC_A_COMMAND 0xf1 |
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#define MAX5821_READ_DAC_B_COMMAND 0xf2 |
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#define MAX5821_EXTENDED_POWER_UP 0x00 |
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#define MAX5821_EXTENDED_POWER_DOWN_MODE0 0x01 |
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#define MAX5821_EXTENDED_POWER_DOWN_MODE1 0x02 |
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#define MAX5821_EXTENDED_POWER_DOWN_MODE2 0x03 |
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#define MAX5821_EXTENDED_DAC_A 0x04 |
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#define MAX5821_EXTENDED_DAC_B 0x08 |
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enum max5821_device_ids { |
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ID_MAX5821, |
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}; |
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struct max5821_data { |
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struct i2c_client *client; |
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struct regulator *vref_reg; |
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unsigned short vref_mv; |
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bool powerdown[MAX5821_MAX_DAC_CHANNELS]; |
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u8 powerdown_mode[MAX5821_MAX_DAC_CHANNELS]; |
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struct mutex lock; |
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}; |
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static const char * const max5821_powerdown_modes[] = { |
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"three_state", |
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"1kohm_to_gnd", |
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"100kohm_to_gnd", |
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}; |
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enum { |
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MAX5821_THREE_STATE, |
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MAX5821_1KOHM_TO_GND, |
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MAX5821_100KOHM_TO_GND |
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}; |
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static int max5821_get_powerdown_mode(struct iio_dev *indio_dev, |
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const struct iio_chan_spec *chan) |
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{ |
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struct max5821_data *st = iio_priv(indio_dev); |
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return st->powerdown_mode[chan->channel]; |
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} |
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static int max5821_set_powerdown_mode(struct iio_dev *indio_dev, |
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const struct iio_chan_spec *chan, |
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unsigned int mode) |
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{ |
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struct max5821_data *st = iio_priv(indio_dev); |
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st->powerdown_mode[chan->channel] = mode; |
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return 0; |
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} |
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static const struct iio_enum max5821_powerdown_mode_enum = { |
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.items = max5821_powerdown_modes, |
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.num_items = ARRAY_SIZE(max5821_powerdown_modes), |
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.get = max5821_get_powerdown_mode, |
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.set = max5821_set_powerdown_mode, |
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}; |
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static ssize_t max5821_read_dac_powerdown(struct iio_dev *indio_dev, |
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uintptr_t private, |
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const struct iio_chan_spec *chan, |
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char *buf) |
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{ |
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struct max5821_data *st = iio_priv(indio_dev); |
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return sysfs_emit(buf, "%d\n", st->powerdown[chan->channel]); |
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} |
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static int max5821_sync_powerdown_mode(struct max5821_data *data, |
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const struct iio_chan_spec *chan) |
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{ |
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u8 outbuf[2]; |
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outbuf[0] = MAX5821_EXTENDED_COMMAND_MODE; |
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if (chan->channel == 0) |
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outbuf[1] = MAX5821_EXTENDED_DAC_A; |
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else |
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outbuf[1] = MAX5821_EXTENDED_DAC_B; |
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if (data->powerdown[chan->channel]) |
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outbuf[1] |= data->powerdown_mode[chan->channel] + 1; |
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else |
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outbuf[1] |= MAX5821_EXTENDED_POWER_UP; |
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return i2c_master_send(data->client, outbuf, 2); |
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} |
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static ssize_t max5821_write_dac_powerdown(struct iio_dev *indio_dev, |
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uintptr_t private, |
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const struct iio_chan_spec *chan, |
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const char *buf, size_t len) |
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{ |
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struct max5821_data *data = iio_priv(indio_dev); |
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bool powerdown; |
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int ret; |
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ret = strtobool(buf, &powerdown); |
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if (ret) |
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return ret; |
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data->powerdown[chan->channel] = powerdown; |
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ret = max5821_sync_powerdown_mode(data, chan); |
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if (ret < 0) |
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return ret; |
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return len; |
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} |
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static const struct iio_chan_spec_ext_info max5821_ext_info[] = { |
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{ |
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.name = "powerdown", |
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.read = max5821_read_dac_powerdown, |
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.write = max5821_write_dac_powerdown, |
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.shared = IIO_SEPARATE, |
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}, |
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IIO_ENUM("powerdown_mode", IIO_SEPARATE, &max5821_powerdown_mode_enum), |
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IIO_ENUM_AVAILABLE("powerdown_mode", &max5821_powerdown_mode_enum), |
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{ }, |
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}; |
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#define MAX5821_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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.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE), \ |
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.ext_info = max5821_ext_info, \ |
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} |
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static const struct iio_chan_spec max5821_channels[] = { |
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MAX5821_CHANNEL(0), |
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MAX5821_CHANNEL(1) |
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}; |
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static const u8 max5821_read_dac_command[] = { |
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MAX5821_READ_DAC_A_COMMAND, |
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MAX5821_READ_DAC_B_COMMAND |
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}; |
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static const u8 max5821_load_dac_command[] = { |
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MAX5821_LOAD_DAC_A_IN_REG_B, |
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MAX5821_LOAD_DAC_B_IN_REG_A |
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}; |
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static int max5821_get_value(struct iio_dev *indio_dev, |
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int *val, int channel) |
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{ |
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struct max5821_data *data = iio_priv(indio_dev); |
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struct i2c_client *client = data->client; |
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u8 outbuf[1]; |
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u8 inbuf[2]; |
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int ret; |
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if ((channel != 0) && (channel != 1)) |
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return -EINVAL; |
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outbuf[0] = max5821_read_dac_command[channel]; |
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mutex_lock(&data->lock); |
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ret = i2c_master_send(client, outbuf, 1); |
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if (ret < 0) { |
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mutex_unlock(&data->lock); |
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return ret; |
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} else if (ret != 1) { |
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mutex_unlock(&data->lock); |
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return -EIO; |
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} |
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ret = i2c_master_recv(client, inbuf, 2); |
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if (ret < 0) { |
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mutex_unlock(&data->lock); |
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return ret; |
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} else if (ret != 2) { |
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mutex_unlock(&data->lock); |
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return -EIO; |
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} |
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mutex_unlock(&data->lock); |
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*val = ((inbuf[0] & 0x0f) << 6) | (inbuf[1] >> 2); |
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return IIO_VAL_INT; |
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} |
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static int max5821_set_value(struct iio_dev *indio_dev, |
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int val, int channel) |
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{ |
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struct max5821_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 ret; |
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if ((val < 0) || (val > 1023)) |
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return -EINVAL; |
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if ((channel != 0) && (channel != 1)) |
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return -EINVAL; |
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outbuf[0] = max5821_load_dac_command[channel]; |
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outbuf[0] |= val >> 6; |
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outbuf[1] = (val & 0x3f) << 2; |
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ret = i2c_master_send(client, outbuf, 2); |
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if (ret < 0) |
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return ret; |
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else if (ret != 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 max5821_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, |
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int *val, int *val2, long mask) |
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{ |
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struct max5821_data *data = iio_priv(indio_dev); |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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return max5821_get_value(indio_dev, val, chan->channel); |
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case IIO_CHAN_INFO_SCALE: |
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*val = data->vref_mv; |
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*val2 = 10; |
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return IIO_VAL_FRACTIONAL_LOG2; |
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default: |
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return -EINVAL; |
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} |
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} |
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static int max5821_write_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, |
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int val, int val2, long mask) |
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{ |
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if (val2 != 0) |
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return -EINVAL; |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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return max5821_set_value(indio_dev, val, chan->channel); |
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default: |
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return -EINVAL; |
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} |
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} |
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static int __maybe_unused max5821_suspend(struct device *dev) |
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{ |
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u8 outbuf[2] = { MAX5821_EXTENDED_COMMAND_MODE, |
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MAX5821_EXTENDED_DAC_A | |
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MAX5821_EXTENDED_DAC_B | |
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MAX5821_EXTENDED_POWER_DOWN_MODE2 }; |
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return i2c_master_send(to_i2c_client(dev), outbuf, 2); |
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} |
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static int __maybe_unused max5821_resume(struct device *dev) |
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{ |
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u8 outbuf[2] = { MAX5821_EXTENDED_COMMAND_MODE, |
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MAX5821_EXTENDED_DAC_A | |
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MAX5821_EXTENDED_DAC_B | |
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MAX5821_EXTENDED_POWER_UP }; |
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return i2c_master_send(to_i2c_client(dev), outbuf, 2); |
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} |
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static SIMPLE_DEV_PM_OPS(max5821_pm_ops, max5821_suspend, max5821_resume); |
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static const struct iio_info max5821_info = { |
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.read_raw = max5821_read_raw, |
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.write_raw = max5821_write_raw, |
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}; |
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static int max5821_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct max5821_data *data; |
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struct iio_dev *indio_dev; |
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u32 tmp; |
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int ret; |
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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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i2c_set_clientdata(client, indio_dev); |
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data->client = client; |
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mutex_init(&data->lock); |
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/* max5821 start in powerdown mode 100Kohm to ground */ |
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for (tmp = 0; tmp < MAX5821_MAX_DAC_CHANNELS; tmp++) { |
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data->powerdown[tmp] = true; |
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data->powerdown_mode[tmp] = MAX5821_100KOHM_TO_GND; |
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} |
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data->vref_reg = devm_regulator_get(&client->dev, "vref"); |
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if (IS_ERR(data->vref_reg)) { |
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ret = PTR_ERR(data->vref_reg); |
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dev_err(&client->dev, |
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"Failed to get vref regulator: %d\n", ret); |
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goto error_free_reg; |
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} |
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ret = regulator_enable(data->vref_reg); |
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if (ret) { |
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dev_err(&client->dev, |
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"Failed to enable vref regulator: %d\n", ret); |
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goto error_free_reg; |
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} |
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ret = regulator_get_voltage(data->vref_reg); |
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if (ret < 0) { |
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dev_err(&client->dev, |
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"Failed to get voltage on regulator: %d\n", ret); |
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goto error_disable_reg; |
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} |
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data->vref_mv = ret / 1000; |
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indio_dev->name = id->name; |
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indio_dev->num_channels = ARRAY_SIZE(max5821_channels); |
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indio_dev->channels = max5821_channels; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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indio_dev->info = &max5821_info; |
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return iio_device_register(indio_dev); |
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error_disable_reg: |
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regulator_disable(data->vref_reg); |
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error_free_reg: |
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return ret; |
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} |
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static int max5821_remove(struct i2c_client *client) |
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{ |
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struct iio_dev *indio_dev = i2c_get_clientdata(client); |
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struct max5821_data *data = iio_priv(indio_dev); |
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iio_device_unregister(indio_dev); |
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regulator_disable(data->vref_reg); |
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return 0; |
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} |
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static const struct i2c_device_id max5821_id[] = { |
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{ "max5821", ID_MAX5821 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, max5821_id); |
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static const struct of_device_id max5821_of_match[] = { |
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{ .compatible = "maxim,max5821" }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(of, max5821_of_match); |
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static struct i2c_driver max5821_driver = { |
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.driver = { |
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.name = "max5821", |
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.of_match_table = max5821_of_match, |
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.pm = &max5821_pm_ops, |
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}, |
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.probe = max5821_probe, |
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.remove = max5821_remove, |
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.id_table = max5821_id, |
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}; |
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module_i2c_driver(max5821_driver); |
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MODULE_AUTHOR("Philippe Reynes <[email protected]>"); |
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MODULE_DESCRIPTION("MAX5821 DAC"); |
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MODULE_LICENSE("GPL v2");
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