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linux/drivers/iio/adc/ad7606_spi.c
Jonathan Cameron 59cea5bc7c iio:adc:ad76060: Move exports into IIO_AD7606 namespace. 
In order to avoid unnecessary pollution of the global symbol namespace
move the core/library functions into a specific namespace and import
that into the various bus specific device drivers that use them.

For more information see https://lwn.net/Articles/760045/

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220130205701.334592-4-jic23@kernel.org
2022-02-18 11:42:26 +00:00

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// SPDX-License-Identifier: GPL-2.0
/*
* AD7606 SPI ADC driver
*
* Copyright 2011 Analog Devices Inc.
*/
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/types.h>
#include <linux/err.h>
#include <linux/iio/iio.h>
#include "ad7606.h"
#define MAX_SPI_FREQ_HZ 23500000 /* VDRIVE above 4.75 V */
#define AD7616_CONFIGURATION_REGISTER 0x02
#define AD7616_OS_MASK GENMASK(4, 2)
#define AD7616_BURST_MODE BIT(6)
#define AD7616_SEQEN_MODE BIT(5)
#define AD7616_RANGE_CH_A_ADDR_OFF 0x04
#define AD7616_RANGE_CH_B_ADDR_OFF 0x06
/*
* Range of channels from a group are stored in 2 registers.
* 0, 1, 2, 3 in a register followed by 4, 5, 6, 7 in second register.
* For channels from second group(8-15) the order is the same, only with
* an offset of 2 for register address.
*/
#define AD7616_RANGE_CH_ADDR(ch) ((ch) >> 2)
/* The range of the channel is stored in 2 bits */
#define AD7616_RANGE_CH_MSK(ch) (0b11 << (((ch) & 0b11) * 2))
#define AD7616_RANGE_CH_MODE(ch, mode) ((mode) << ((((ch) & 0b11)) * 2))
#define AD7606_CONFIGURATION_REGISTER 0x02
#define AD7606_SINGLE_DOUT 0x00
/*
* Range for AD7606B channels are stored in registers starting with address 0x3.
* Each register stores range for 2 channels(4 bits per channel).
*/
#define AD7606_RANGE_CH_MSK(ch) (GENMASK(3, 0) << (4 * ((ch) & 0x1)))
#define AD7606_RANGE_CH_MODE(ch, mode) \
((GENMASK(3, 0) & mode) << (4 * ((ch) & 0x1)))
#define AD7606_RANGE_CH_ADDR(ch) (0x03 + ((ch) >> 1))
#define AD7606_OS_MODE 0x08
static const struct iio_chan_spec ad7616_sw_channels[] = {
IIO_CHAN_SOFT_TIMESTAMP(16),
AD7616_CHANNEL(0),
AD7616_CHANNEL(1),
AD7616_CHANNEL(2),
AD7616_CHANNEL(3),
AD7616_CHANNEL(4),
AD7616_CHANNEL(5),
AD7616_CHANNEL(6),
AD7616_CHANNEL(7),
AD7616_CHANNEL(8),
AD7616_CHANNEL(9),
AD7616_CHANNEL(10),
AD7616_CHANNEL(11),
AD7616_CHANNEL(12),
AD7616_CHANNEL(13),
AD7616_CHANNEL(14),
AD7616_CHANNEL(15),
};
static const struct iio_chan_spec ad7606b_sw_channels[] = {
IIO_CHAN_SOFT_TIMESTAMP(8),
AD7616_CHANNEL(0),
AD7616_CHANNEL(1),
AD7616_CHANNEL(2),
AD7616_CHANNEL(3),
AD7616_CHANNEL(4),
AD7616_CHANNEL(5),
AD7616_CHANNEL(6),
AD7616_CHANNEL(7),
};
static const unsigned int ad7606B_oversampling_avail[9] = {
1, 2, 4, 8, 16, 32, 64, 128, 256
};
static u16 ad7616_spi_rd_wr_cmd(int addr, char isWriteOp)
{
/*
* The address of register consist of one w/r bit
* 6 bits of address followed by one reserved bit.
*/
return ((addr & 0x7F) << 1) | ((isWriteOp & 0x1) << 7);
}
static u16 ad7606B_spi_rd_wr_cmd(int addr, char is_write_op)
{
/*
* The address of register consists of one bit which
* specifies a read command placed in bit 6, followed by
* 6 bits of address.
*/
return (addr & 0x3F) | (((~is_write_op) & 0x1) << 6);
}
static int ad7606_spi_read_block(struct device *dev,
int count, void *buf)
{
struct spi_device *spi = to_spi_device(dev);
int i, ret;
unsigned short *data = buf;
__be16 *bdata = buf;
ret = spi_read(spi, buf, count * 2);
if (ret < 0) {
dev_err(&spi->dev, "SPI read error\n");
return ret;
}
for (i = 0; i < count; i++)
data[i] = be16_to_cpu(bdata[i]);
return 0;
}
static int ad7606_spi_reg_read(struct ad7606_state *st, unsigned int addr)
{
struct spi_device *spi = to_spi_device(st->dev);
struct spi_transfer t[] = {
{
.tx_buf = &st->d16[0],
.len = 2,
.cs_change = 0,
}, {
.rx_buf = &st->d16[1],
.len = 2,
},
};
int ret;
st->d16[0] = cpu_to_be16(st->bops->rd_wr_cmd(addr, 0) << 8);
ret = spi_sync_transfer(spi, t, ARRAY_SIZE(t));
if (ret < 0)
return ret;
return be16_to_cpu(st->d16[1]);
}
static int ad7606_spi_reg_write(struct ad7606_state *st,
unsigned int addr,
unsigned int val)
{
struct spi_device *spi = to_spi_device(st->dev);
st->d16[0] = cpu_to_be16((st->bops->rd_wr_cmd(addr, 1) << 8) |
(val & 0x1FF));
return spi_write(spi, &st->d16[0], sizeof(st->d16[0]));
}
static int ad7606_spi_write_mask(struct ad7606_state *st,
unsigned int addr,
unsigned long mask,
unsigned int val)
{
int readval;
readval = st->bops->reg_read(st, addr);
if (readval < 0)
return readval;
readval &= ~mask;
readval |= val;
return st->bops->reg_write(st, addr, readval);
}
static int ad7616_write_scale_sw(struct iio_dev *indio_dev, int ch, int val)
{
struct ad7606_state *st = iio_priv(indio_dev);
unsigned int ch_addr, mode, ch_index;
/*
* Ad7616 has 16 channels divided in group A and group B.
* The range of channels from A are stored in registers with address 4
* while channels from B are stored in register with address 6.
* The last bit from channels determines if it is from group A or B
* because the order of channels in iio is 0A, 0B, 1A, 1B...
*/
ch_index = ch >> 1;
ch_addr = AD7616_RANGE_CH_ADDR(ch_index);
if ((ch & 0x1) == 0) /* channel A */
ch_addr += AD7616_RANGE_CH_A_ADDR_OFF;
else /* channel B */
ch_addr += AD7616_RANGE_CH_B_ADDR_OFF;
/* 0b01 for 2.5v, 0b10 for 5v and 0b11 for 10v */
mode = AD7616_RANGE_CH_MODE(ch_index, ((val + 1) & 0b11));
return st->bops->write_mask(st, ch_addr, AD7616_RANGE_CH_MSK(ch_index),
mode);
}
static int ad7616_write_os_sw(struct iio_dev *indio_dev, int val)
{
struct ad7606_state *st = iio_priv(indio_dev);
return st->bops->write_mask(st, AD7616_CONFIGURATION_REGISTER,
AD7616_OS_MASK, val << 2);
}
static int ad7606_write_scale_sw(struct iio_dev *indio_dev, int ch, int val)
{
struct ad7606_state *st = iio_priv(indio_dev);
return ad7606_spi_write_mask(st,
AD7606_RANGE_CH_ADDR(ch),
AD7606_RANGE_CH_MSK(ch),
AD7606_RANGE_CH_MODE(ch, val));
}
static int ad7606_write_os_sw(struct iio_dev *indio_dev, int val)
{
struct ad7606_state *st = iio_priv(indio_dev);
return ad7606_spi_reg_write(st, AD7606_OS_MODE, val);
}
static int ad7616_sw_mode_config(struct iio_dev *indio_dev)
{
struct ad7606_state *st = iio_priv(indio_dev);
/*
* Scale can be configured individually for each channel
* in software mode.
*/
indio_dev->channels = ad7616_sw_channels;
st->write_scale = ad7616_write_scale_sw;
st->write_os = &ad7616_write_os_sw;
/* Activate Burst mode and SEQEN MODE */
return st->bops->write_mask(st,
AD7616_CONFIGURATION_REGISTER,
AD7616_BURST_MODE | AD7616_SEQEN_MODE,
AD7616_BURST_MODE | AD7616_SEQEN_MODE);
}
static int ad7606B_sw_mode_config(struct iio_dev *indio_dev)
{
struct ad7606_state *st = iio_priv(indio_dev);
unsigned long os[3] = {1};
/*
* Software mode is enabled when all three oversampling
* pins are set to high. If oversampling gpios are defined
* in the device tree, then they need to be set to high,
* otherwise, they must be hardwired to VDD
*/
if (st->gpio_os) {
gpiod_set_array_value(ARRAY_SIZE(os),
st->gpio_os->desc, st->gpio_os->info, os);
}
/* OS of 128 and 256 are available only in software mode */
st->oversampling_avail = ad7606B_oversampling_avail;
st->num_os_ratios = ARRAY_SIZE(ad7606B_oversampling_avail);
st->write_scale = ad7606_write_scale_sw;
st->write_os = &ad7606_write_os_sw;
/* Configure device spi to output on a single channel */
st->bops->reg_write(st,
AD7606_CONFIGURATION_REGISTER,
AD7606_SINGLE_DOUT);
/*
* Scale can be configured individually for each channel
* in software mode.
*/
indio_dev->channels = ad7606b_sw_channels;
return 0;
}
static const struct ad7606_bus_ops ad7606_spi_bops = {
.read_block = ad7606_spi_read_block,
};
static const struct ad7606_bus_ops ad7616_spi_bops = {
.read_block = ad7606_spi_read_block,
.reg_read = ad7606_spi_reg_read,
.reg_write = ad7606_spi_reg_write,
.write_mask = ad7606_spi_write_mask,
.rd_wr_cmd = ad7616_spi_rd_wr_cmd,
.sw_mode_config = ad7616_sw_mode_config,
};
static const struct ad7606_bus_ops ad7606B_spi_bops = {
.read_block = ad7606_spi_read_block,
.reg_read = ad7606_spi_reg_read,
.reg_write = ad7606_spi_reg_write,
.write_mask = ad7606_spi_write_mask,
.rd_wr_cmd = ad7606B_spi_rd_wr_cmd,
.sw_mode_config = ad7606B_sw_mode_config,
};
static int ad7606_spi_probe(struct spi_device *spi)
{
const struct spi_device_id *id = spi_get_device_id(spi);
const struct ad7606_bus_ops *bops;
switch (id->driver_data) {
case ID_AD7616:
bops = &ad7616_spi_bops;
break;
case ID_AD7606B:
bops = &ad7606B_spi_bops;
break;
default:
bops = &ad7606_spi_bops;
break;
}
return ad7606_probe(&spi->dev, spi->irq, NULL,
id->name, id->driver_data,
bops);
}
static const struct spi_device_id ad7606_id_table[] = {
{ "ad7605-4", ID_AD7605_4 },
{ "ad7606-4", ID_AD7606_4 },
{ "ad7606-6", ID_AD7606_6 },
{ "ad7606-8", ID_AD7606_8 },
{ "ad7606b", ID_AD7606B },
{ "ad7616", ID_AD7616 },
{}
};
MODULE_DEVICE_TABLE(spi, ad7606_id_table);
static const struct of_device_id ad7606_of_match[] = {
{ .compatible = "adi,ad7605-4" },
{ .compatible = "adi,ad7606-4" },
{ .compatible = "adi,ad7606-6" },
{ .compatible = "adi,ad7606-8" },
{ .compatible = "adi,ad7606b" },
{ .compatible = "adi,ad7616" },
{ },
};
MODULE_DEVICE_TABLE(of, ad7606_of_match);
static struct spi_driver ad7606_driver = {
.driver = {
.name = "ad7606",
.of_match_table = ad7606_of_match,
.pm = AD7606_PM_OPS,
},
.probe = ad7606_spi_probe,
.id_table = ad7606_id_table,
};
module_spi_driver(ad7606_driver);
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS(IIO_AD7606);
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