mirror of
https://github.com/torvalds/linux.git
synced 2024-09-20 23:13:00 +00:00
iio: dac: driver for MCP4821
Adds driver for the MCP48xx series of DACs.
Device uses a simplex SPI channel. To set the value of an output channel,
a 16-bit data of following format must be written:
Bit field | Description
15 [MSB] | Channel selection bit
0 -> Channel A
1 -> Channel B
13 | Output Gain Selection bit
0 -> 2x Gain (Vref = 4.096V)
1 -> 1x Gain (Vref = 2.048V)
12 | Output Shutdown Control bit
0 -> Shutdown the selected channel
1 -> Active mode operation
11-0 [LSB]| DAC Input Data bits
Value's big endian representation is taken as input for the
selected DAC channel. For devices with a resolution of less
than 12-bits, only the x most significant bits are considered
where x is the resolution of the device.
Reference: Page#22 [MCP48x2 Datasheet]
Supported devices:
+---------+--------------+-------------+
| Device | Resolution | Channels |
|---------|--------------|-------------|
| MCP4801 | 8-bit | 1 |
| MCP4802 | 8-bit | 2 |
| MCP4811 | 10-bit | 1 |
| MCP4812 | 10-bit | 2 |
| MCP4821 | 12-bit | 1 |
| MCP4822 | 12-bit | 2 |
+---------+--------------+-------------+
Devices tested:
MCP4821 [12-bit single channel]
MCP4802 [8-bit dual channel]
Tested on Raspberry Pi Zero 2W
Datasheet: https://ww1.microchip.com/downloads/en/DeviceDoc/22244B.pdf #MCP48x1
Datasheet: https://ww1.microchip.com/downloads/en/DeviceDoc/20002249B.pdf #MCP48x2
Signed-off-by: Anshul Dalal <anshulusr@gmail.com>
Link: https://lore.kernel.org/r/20231220151954.154595-2-anshulusr@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Anshul Dalal
Jonathan Cameron
parent
6b626eee66
commit
cdf3ecb0d8
|
|
@ -13174,6 +13174,13 @@ F: Documentation/ABI/testing/sysfs-bus-iio-potentiometer-mcp4531
|
|||
F: drivers/iio/potentiometer/mcp4018.c
|
||||
F: drivers/iio/potentiometer/mcp4531.c
|
||||
|
||||
MCP4821 DAC DRIVER
|
||||
M: Anshul Dalal <anshulusr@gmail.com>
|
||||
L: linux-iio@vger.kernel.org
|
||||
S: Maintained
|
||||
F: Documentation/devicetree/bindings/iio/dac/microchip,mcp4821.yaml
|
||||
F: drivers/iio/dac/mcp4821.c
|
||||
|
||||
MCR20A IEEE-802.15.4 RADIO DRIVER
|
||||
M: Stefan Schmidt <stefan@datenfreihafen.org>
|
||||
L: linux-wpan@vger.kernel.org
|
||||
|
|
|
|||
|
|
@ -400,6 +400,16 @@ config MCP4728
|
|||
To compile this driver as a module, choose M here: the module
|
||||
will be called mcp4728.
|
||||
|
||||
config MCP4821
|
||||
tristate "MCP4801/02/11/12/21/22 DAC driver"
|
||||
depends on SPI
|
||||
help
|
||||
Say yes here to build the driver for the Microchip MCP4801
|
||||
MCP4802, MCP4811, MCP4812, MCP4821 and MCP4822 DAC devices.
|
||||
|
||||
To compile this driver as a module, choose M here: the module
|
||||
will be called mcp4821.
|
||||
|
||||
config MCP4922
|
||||
tristate "MCP4902, MCP4912, MCP4922 DAC driver"
|
||||
depends on SPI
|
||||
|
|
|
|||
|
|
@ -42,6 +42,7 @@ obj-$(CONFIG_MAX5522) += max5522.o
|
|||
obj-$(CONFIG_MAX5821) += max5821.o
|
||||
obj-$(CONFIG_MCP4725) += mcp4725.o
|
||||
obj-$(CONFIG_MCP4728) += mcp4728.o
|
||||
obj-$(CONFIG_MCP4821) += mcp4821.o
|
||||
obj-$(CONFIG_MCP4922) += mcp4922.o
|
||||
obj-$(CONFIG_STM32_DAC_CORE) += stm32-dac-core.o
|
||||
obj-$(CONFIG_STM32_DAC) += stm32-dac.o
|
||||
|
|
|
|||
236
drivers/iio/dac/mcp4821.c
Normal file
236
drivers/iio/dac/mcp4821.c
Normal file
|
|
@ -0,0 +1,236 @@
|
|||
// SPDX-License-Identifier: GPL-2.0-or-later
|
||||
/*
|
||||
* Copyright (C) 2023 Anshul Dalal <anshulusr@gmail.com>
|
||||
*
|
||||
* Driver for Microchip MCP4801, MCP4802, MCP4811, MCP4812, MCP4821 and MCP4822
|
||||
*
|
||||
* Based on the work of:
|
||||
* Michael Welling (MCP4922 Driver)
|
||||
*
|
||||
* Datasheet:
|
||||
* MCP48x1: https://ww1.microchip.com/downloads/en/DeviceDoc/22244B.pdf
|
||||
* MCP48x2: https://ww1.microchip.com/downloads/en/DeviceDoc/20002249B.pdf
|
||||
*
|
||||
* TODO:
|
||||
* - Configurable gain
|
||||
* - Regulator control
|
||||
*/
|
||||
|
||||
#include <linux/module.h>
|
||||
#include <linux/of.h>
|
||||
#include <linux/spi/spi.h>
|
||||
|
||||
#include <linux/iio/iio.h>
|
||||
#include <linux/iio/types.h>
|
||||
|
||||
#include <asm/unaligned.h>
|
||||
|
||||
#define MCP4821_ACTIVE_MODE BIT(12)
|
||||
#define MCP4802_SECOND_CHAN BIT(15)
|
||||
|
||||
/* DAC uses an internal Voltage reference of 4.096V at a gain of 2x */
|
||||
#define MCP4821_2X_GAIN_VREF_MV 4096
|
||||
|
||||
enum mcp4821_supported_drvice_ids {
|
||||
ID_MCP4801,
|
||||
ID_MCP4802,
|
||||
ID_MCP4811,
|
||||
ID_MCP4812,
|
||||
ID_MCP4821,
|
||||
ID_MCP4822,
|
||||
};
|
||||
|
||||
struct mcp4821_state {
|
||||
struct spi_device *spi;
|
||||
u16 dac_value[2];
|
||||
};
|
||||
|
||||
struct mcp4821_chip_info {
|
||||
const char *name;
|
||||
int num_channels;
|
||||
const struct iio_chan_spec channels[2];
|
||||
};
|
||||
|
||||
#define MCP4821_CHAN(channel_id, resolution) \
|
||||
{ \
|
||||
.type = IIO_VOLTAGE, .output = 1, .indexed = 1, \
|
||||
.channel = (channel_id), \
|
||||
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
|
||||
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
|
||||
.scan_type = { \
|
||||
.realbits = (resolution), \
|
||||
.shift = 12 - (resolution), \
|
||||
}, \
|
||||
}
|
||||
|
||||
static const struct mcp4821_chip_info mcp4821_chip_info_table[6] = {
|
||||
[ID_MCP4801] = {
|
||||
.name = "mcp4801",
|
||||
.num_channels = 1,
|
||||
.channels = {
|
||||
MCP4821_CHAN(0, 8),
|
||||
},
|
||||
},
|
||||
[ID_MCP4802] = {
|
||||
.name = "mcp4802",
|
||||
.num_channels = 2,
|
||||
.channels = {
|
||||
MCP4821_CHAN(0, 8),
|
||||
MCP4821_CHAN(1, 8),
|
||||
},
|
||||
},
|
||||
[ID_MCP4811] = {
|
||||
.name = "mcp4811",
|
||||
.num_channels = 1,
|
||||
.channels = {
|
||||
MCP4821_CHAN(0, 10),
|
||||
},
|
||||
},
|
||||
[ID_MCP4812] = {
|
||||
.name = "mcp4812",
|
||||
.num_channels = 2,
|
||||
.channels = {
|
||||
MCP4821_CHAN(0, 10),
|
||||
MCP4821_CHAN(1, 10),
|
||||
},
|
||||
},
|
||||
[ID_MCP4821] = {
|
||||
.name = "mcp4821",
|
||||
.num_channels = 1,
|
||||
.channels = {
|
||||
MCP4821_CHAN(0, 12),
|
||||
},
|
||||
},
|
||||
[ID_MCP4822] = {
|
||||
.name = "mcp4822",
|
||||
.num_channels = 2,
|
||||
.channels = {
|
||||
MCP4821_CHAN(0, 12),
|
||||
MCP4821_CHAN(1, 12),
|
||||
},
|
||||
},
|
||||
};
|
||||
|
||||
static int mcp4821_read_raw(struct iio_dev *indio_dev,
|
||||
struct iio_chan_spec const *chan, int *val,
|
||||
int *val2, long mask)
|
||||
{
|
||||
struct mcp4821_state *state;
|
||||
|
||||
switch (mask) {
|
||||
case IIO_CHAN_INFO_RAW:
|
||||
state = iio_priv(indio_dev);
|
||||
*val = state->dac_value[chan->channel];
|
||||
return IIO_VAL_INT;
|
||||
case IIO_CHAN_INFO_SCALE:
|
||||
*val = MCP4821_2X_GAIN_VREF_MV;
|
||||
*val2 = chan->scan_type.realbits;
|
||||
return IIO_VAL_FRACTIONAL_LOG2;
|
||||
default:
|
||||
return -EINVAL;
|
||||
}
|
||||
}
|
||||
|
||||
static int mcp4821_write_raw(struct iio_dev *indio_dev,
|
||||
struct iio_chan_spec const *chan, int val,
|
||||
int val2, long mask)
|
||||
{
|
||||
struct mcp4821_state *state = iio_priv(indio_dev);
|
||||
u16 write_val;
|
||||
__be16 write_buffer;
|
||||
int ret;
|
||||
|
||||
if (val2 != 0)
|
||||
return -EINVAL;
|
||||
|
||||
if (val < 0 || val >= BIT(chan->scan_type.realbits))
|
||||
return -EINVAL;
|
||||
|
||||
if (mask != IIO_CHAN_INFO_RAW)
|
||||
return -EINVAL;
|
||||
|
||||
write_val = MCP4821_ACTIVE_MODE | val << chan->scan_type.shift;
|
||||
if (chan->channel)
|
||||
write_val |= MCP4802_SECOND_CHAN;
|
||||
|
||||
write_buffer = cpu_to_be16(write_val);
|
||||
ret = spi_write(state->spi, &write_buffer, sizeof(write_buffer));
|
||||
if (ret) {
|
||||
dev_err(&state->spi->dev, "Failed to write to device: %d", ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
state->dac_value[chan->channel] = val;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static const struct iio_info mcp4821_info = {
|
||||
.read_raw = &mcp4821_read_raw,
|
||||
.write_raw = &mcp4821_write_raw,
|
||||
};
|
||||
|
||||
static int mcp4821_probe(struct spi_device *spi)
|
||||
{
|
||||
struct iio_dev *indio_dev;
|
||||
struct mcp4821_state *state;
|
||||
const struct mcp4821_chip_info *info;
|
||||
|
||||
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));
|
||||
if (indio_dev == NULL)
|
||||
return -ENOMEM;
|
||||
|
||||
state = iio_priv(indio_dev);
|
||||
state->spi = spi;
|
||||
|
||||
info = spi_get_device_match_data(spi);
|
||||
indio_dev->name = info->name;
|
||||
indio_dev->info = &mcp4821_info;
|
||||
indio_dev->modes = INDIO_DIRECT_MODE;
|
||||
indio_dev->channels = info->channels;
|
||||
indio_dev->num_channels = info->num_channels;
|
||||
|
||||
return devm_iio_device_register(&spi->dev, indio_dev);
|
||||
}
|
||||
|
||||
#define MCP4821_COMPATIBLE(of_compatible, id) \
|
||||
{ \
|
||||
.compatible = of_compatible, \
|
||||
.data = &mcp4821_chip_info_table[id] \
|
||||
}
|
||||
|
||||
static const struct of_device_id mcp4821_of_table[] = {
|
||||
MCP4821_COMPATIBLE("microchip,mcp4801", ID_MCP4801),
|
||||
MCP4821_COMPATIBLE("microchip,mcp4802", ID_MCP4802),
|
||||
MCP4821_COMPATIBLE("microchip,mcp4811", ID_MCP4811),
|
||||
MCP4821_COMPATIBLE("microchip,mcp4812", ID_MCP4812),
|
||||
MCP4821_COMPATIBLE("microchip,mcp4821", ID_MCP4821),
|
||||
MCP4821_COMPATIBLE("microchip,mcp4822", ID_MCP4822),
|
||||
{ /* Sentinel */ }
|
||||
};
|
||||
MODULE_DEVICE_TABLE(of, mcp4821_of_table);
|
||||
|
||||
static const struct spi_device_id mcp4821_id_table[] = {
|
||||
{ "mcp4801", (kernel_ulong_t)&mcp4821_chip_info_table[ID_MCP4801]},
|
||||
{ "mcp4802", (kernel_ulong_t)&mcp4821_chip_info_table[ID_MCP4802]},
|
||||
{ "mcp4811", (kernel_ulong_t)&mcp4821_chip_info_table[ID_MCP4811]},
|
||||
{ "mcp4812", (kernel_ulong_t)&mcp4821_chip_info_table[ID_MCP4812]},
|
||||
{ "mcp4821", (kernel_ulong_t)&mcp4821_chip_info_table[ID_MCP4821]},
|
||||
{ "mcp4822", (kernel_ulong_t)&mcp4821_chip_info_table[ID_MCP4822]},
|
||||
{ /* Sentinel */ }
|
||||
};
|
||||
MODULE_DEVICE_TABLE(spi, mcp4821_id_table);
|
||||
|
||||
static struct spi_driver mcp4821_driver = {
|
||||
.driver = {
|
||||
.name = "mcp4821",
|
||||
.of_match_table = mcp4821_of_table,
|
||||
},
|
||||
.probe = mcp4821_probe,
|
||||
.id_table = mcp4821_id_table,
|
||||
};
|
||||
module_spi_driver(mcp4821_driver);
|
||||
|
||||
MODULE_AUTHOR("Anshul Dalal <anshulusr@gmail.com>");
|
||||
MODULE_DESCRIPTION("Microchip MCP4821 DAC Driver");
|
||||
MODULE_LICENSE("GPL");
|
||||
Loading…
Reference in New Issue
Block a user