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linux-next/drivers/iio/counter/104-quad-8.c
William Breathitt Gray 17f0361936 iio: 104-quad-8: Provide defines for magic numbers
This patch adds several register and bit defines to help improve the
clarity of the code by cleaning up magic numbers throughout the driver.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-06-10 11:52:30 +01:00

632 lines
18 KiB
C

/*
* IIO driver for the ACCES 104-QUAD-8
* Copyright (C) 2016 William Breathitt Gray
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* 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.
*
* This driver supports the ACCES 104-QUAD-8 and ACCES 104-QUAD-4.
*/
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/iio/iio.h>
#include <linux/iio/types.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/isa.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#define QUAD8_EXTENT 32
static unsigned int base[max_num_isa_dev(QUAD8_EXTENT)];
static unsigned int num_quad8;
module_param_array(base, uint, &num_quad8, 0);
MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses");
#define QUAD8_NUM_COUNTERS 8
/**
* struct quad8_iio - IIO device private data structure
* @preset: array of preset values
* @count_mode: array of count mode configurations
* @quadrature_mode: array of quadrature mode configurations
* @quadrature_scale: array of quadrature mode scale configurations
* @ab_enable: array of A and B inputs enable configurations
* @preset_enable: array of set_to_preset_on_index attribute configurations
* @synchronous_mode: array of index function synchronous mode configurations
* @index_polarity: array of index function polarity configurations
* @base: base port address of the IIO device
*/
struct quad8_iio {
unsigned int preset[QUAD8_NUM_COUNTERS];
unsigned int count_mode[QUAD8_NUM_COUNTERS];
unsigned int quadrature_mode[QUAD8_NUM_COUNTERS];
unsigned int quadrature_scale[QUAD8_NUM_COUNTERS];
unsigned int ab_enable[QUAD8_NUM_COUNTERS];
unsigned int preset_enable[QUAD8_NUM_COUNTERS];
unsigned int synchronous_mode[QUAD8_NUM_COUNTERS];
unsigned int index_polarity[QUAD8_NUM_COUNTERS];
unsigned int base;
};
#define QUAD8_REG_CHAN_OP 0x11
#define QUAD8_REG_INDEX_INPUT_LEVELS 0x16
/* Borrow Toggle flip-flop */
#define QUAD8_FLAG_BT BIT(0)
/* Carry Toggle flip-flop */
#define QUAD8_FLAG_CT BIT(1)
/* Error flag */
#define QUAD8_FLAG_E BIT(4)
/* Up/Down flag */
#define QUAD8_FLAG_UD BIT(5)
/* Reset and Load Signal Decoders */
#define QUAD8_CTR_RLD 0x00
/* Counter Mode Register */
#define QUAD8_CTR_CMR 0x20
/* Input / Output Control Register */
#define QUAD8_CTR_IOR 0x40
/* Index Control Register */
#define QUAD8_CTR_IDR 0x60
/* Reset Byte Pointer (three byte data pointer) */
#define QUAD8_RLD_RESET_BP 0x01
/* Reset Counter */
#define QUAD8_RLD_RESET_CNTR 0x02
/* Reset Borrow Toggle, Carry Toggle, Compare Toggle, and Sign flags */
#define QUAD8_RLD_RESET_FLAGS 0x04
/* Reset Error flag */
#define QUAD8_RLD_RESET_E 0x06
/* Preset Register to Counter */
#define QUAD8_RLD_PRESET_CNTR 0x08
/* Transfer Counter to Output Latch */
#define QUAD8_RLD_CNTR_OUT 0x10
#define QUAD8_CHAN_OP_ENABLE_COUNTERS 0x00
#define QUAD8_CHAN_OP_RESET_COUNTERS 0x01
static int quad8_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val, int *val2, long mask)
{
struct quad8_iio *const priv = iio_priv(indio_dev);
const int base_offset = priv->base + 2 * chan->channel;
unsigned int flags;
unsigned int borrow;
unsigned int carry;
int i;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (chan->type == IIO_INDEX) {
*val = !!(inb(priv->base + QUAD8_REG_INDEX_INPUT_LEVELS)
& BIT(chan->channel));
return IIO_VAL_INT;
}
flags = inb(base_offset + 1);
borrow = flags & QUAD8_FLAG_BT;
carry = !!(flags & QUAD8_FLAG_CT);
/* Borrow XOR Carry effectively doubles count range */
*val = (borrow ^ carry) << 24;
/* Reset Byte Pointer; transfer Counter to Output Latch */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_CNTR_OUT,
base_offset + 1);
for (i = 0; i < 3; i++)
*val |= (unsigned int)inb(base_offset) << (8 * i);
return IIO_VAL_INT;
case IIO_CHAN_INFO_ENABLE:
*val = priv->ab_enable[chan->channel];
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 1;
*val2 = priv->quadrature_scale[chan->channel];
return IIO_VAL_FRACTIONAL_LOG2;
}
return -EINVAL;
}
static int quad8_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val, int val2, long mask)
{
struct quad8_iio *const priv = iio_priv(indio_dev);
const int base_offset = priv->base + 2 * chan->channel;
int i;
unsigned int ior_cfg;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (chan->type == IIO_INDEX)
return -EINVAL;
/* Only 24-bit values are supported */
if ((unsigned int)val > 0xFFFFFF)
return -EINVAL;
/* Reset Byte Pointer */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
/* Counter can only be set via Preset Register */
for (i = 0; i < 3; i++)
outb(val >> (8 * i), base_offset);
/* Transfer Preset Register to Counter */
outb(QUAD8_CTR_RLD | QUAD8_RLD_PRESET_CNTR, base_offset + 1);
/* Reset Byte Pointer */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
/* Set Preset Register back to original value */
val = priv->preset[chan->channel];
for (i = 0; i < 3; i++)
outb(val >> (8 * i), base_offset);
/* Reset Borrow, Carry, Compare, and Sign flags */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1);
/* Reset Error flag */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1);
return 0;
case IIO_CHAN_INFO_ENABLE:
/* only boolean values accepted */
if (val < 0 || val > 1)
return -EINVAL;
priv->ab_enable[chan->channel] = val;
ior_cfg = val | priv->preset_enable[chan->channel] << 1;
/* Load I/O control configuration */
outb(QUAD8_CTR_IOR | ior_cfg, base_offset + 1);
return 0;
case IIO_CHAN_INFO_SCALE:
/* Quadrature scaling only available in quadrature mode */
if (!priv->quadrature_mode[chan->channel] && (val2 || val != 1))
return -EINVAL;
/* Only three gain states (1, 0.5, 0.25) */
if (val == 1 && !val2)
priv->quadrature_scale[chan->channel] = 0;
else if (!val)
switch (val2) {
case 500000:
priv->quadrature_scale[chan->channel] = 1;
break;
case 250000:
priv->quadrature_scale[chan->channel] = 2;
break;
default:
return -EINVAL;
}
else
return -EINVAL;
return 0;
}
return -EINVAL;
}
static const struct iio_info quad8_info = {
.read_raw = quad8_read_raw,
.write_raw = quad8_write_raw
};
static ssize_t quad8_read_preset(struct iio_dev *indio_dev, uintptr_t private,
const struct iio_chan_spec *chan, char *buf)
{
const struct quad8_iio *const priv = iio_priv(indio_dev);
return snprintf(buf, PAGE_SIZE, "%u\n", priv->preset[chan->channel]);
}
static ssize_t quad8_write_preset(struct iio_dev *indio_dev, uintptr_t private,
const struct iio_chan_spec *chan, const char *buf, size_t len)
{
struct quad8_iio *const priv = iio_priv(indio_dev);
const int base_offset = priv->base + 2 * chan->channel;
unsigned int preset;
int ret;
int i;
ret = kstrtouint(buf, 0, &preset);
if (ret)
return ret;
/* Only 24-bit values are supported */
if (preset > 0xFFFFFF)
return -EINVAL;
priv->preset[chan->channel] = preset;
/* Reset Byte Pointer */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
/* Set Preset Register */
for (i = 0; i < 3; i++)
outb(preset >> (8 * i), base_offset);
return len;
}
static ssize_t quad8_read_set_to_preset_on_index(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan, char *buf)
{
const struct quad8_iio *const priv = iio_priv(indio_dev);
return snprintf(buf, PAGE_SIZE, "%u\n",
!priv->preset_enable[chan->channel]);
}
static ssize_t quad8_write_set_to_preset_on_index(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
size_t len)
{
struct quad8_iio *const priv = iio_priv(indio_dev);
const int base_offset = priv->base + 2 * chan->channel + 1;
bool preset_enable;
int ret;
unsigned int ior_cfg;
ret = kstrtobool(buf, &preset_enable);
if (ret)
return ret;
/* Preset enable is active low in Input/Output Control register */
preset_enable = !preset_enable;
priv->preset_enable[chan->channel] = preset_enable;
ior_cfg = priv->ab_enable[chan->channel] |
(unsigned int)preset_enable << 1;
/* Load I/O control configuration to Input / Output Control Register */
outb(QUAD8_CTR_IOR | ior_cfg, base_offset);
return len;
}
static const char *const quad8_noise_error_states[] = {
"No excessive noise is present at the count inputs",
"Excessive noise is present at the count inputs"
};
static int quad8_get_noise_error(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct quad8_iio *const priv = iio_priv(indio_dev);
const int base_offset = priv->base + 2 * chan->channel + 1;
return !!(inb(base_offset) & QUAD8_FLAG_E);
}
static const struct iio_enum quad8_noise_error_enum = {
.items = quad8_noise_error_states,
.num_items = ARRAY_SIZE(quad8_noise_error_states),
.get = quad8_get_noise_error
};
static const char *const quad8_count_direction_states[] = {
"down",
"up"
};
static int quad8_get_count_direction(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct quad8_iio *const priv = iio_priv(indio_dev);
const int base_offset = priv->base + 2 * chan->channel + 1;
return !!(inb(base_offset) & QUAD8_FLAG_UD);
}
static const struct iio_enum quad8_count_direction_enum = {
.items = quad8_count_direction_states,
.num_items = ARRAY_SIZE(quad8_count_direction_states),
.get = quad8_get_count_direction
};
static const char *const quad8_count_modes[] = {
"normal",
"range limit",
"non-recycle",
"modulo-n"
};
static int quad8_set_count_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, unsigned int count_mode)
{
struct quad8_iio *const priv = iio_priv(indio_dev);
unsigned int mode_cfg = count_mode << 1;
const int base_offset = priv->base + 2 * chan->channel + 1;
priv->count_mode[chan->channel] = count_mode;
/* Add quadrature mode configuration */
if (priv->quadrature_mode[chan->channel])
mode_cfg |= (priv->quadrature_scale[chan->channel] + 1) << 3;
/* Load mode configuration to Counter Mode Register */
outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
return 0;
}
static int quad8_get_count_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
const struct quad8_iio *const priv = iio_priv(indio_dev);
return priv->count_mode[chan->channel];
}
static const struct iio_enum quad8_count_mode_enum = {
.items = quad8_count_modes,
.num_items = ARRAY_SIZE(quad8_count_modes),
.set = quad8_set_count_mode,
.get = quad8_get_count_mode
};
static const char *const quad8_synchronous_modes[] = {
"non-synchronous",
"synchronous"
};
static int quad8_set_synchronous_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, unsigned int synchronous_mode)
{
struct quad8_iio *const priv = iio_priv(indio_dev);
const unsigned int idr_cfg = synchronous_mode |
priv->index_polarity[chan->channel] << 1;
const int base_offset = priv->base + 2 * chan->channel + 1;
/* Index function must be non-synchronous in non-quadrature mode */
if (synchronous_mode && !priv->quadrature_mode[chan->channel])
return -EINVAL;
priv->synchronous_mode[chan->channel] = synchronous_mode;
/* Load Index Control configuration to Index Control Register */
outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
return 0;
}
static int quad8_get_synchronous_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
const struct quad8_iio *const priv = iio_priv(indio_dev);
return priv->synchronous_mode[chan->channel];
}
static const struct iio_enum quad8_synchronous_mode_enum = {
.items = quad8_synchronous_modes,
.num_items = ARRAY_SIZE(quad8_synchronous_modes),
.set = quad8_set_synchronous_mode,
.get = quad8_get_synchronous_mode
};
static const char *const quad8_quadrature_modes[] = {
"non-quadrature",
"quadrature"
};
static int quad8_set_quadrature_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, unsigned int quadrature_mode)
{
struct quad8_iio *const priv = iio_priv(indio_dev);
unsigned int mode_cfg = priv->count_mode[chan->channel] << 1;
const int base_offset = priv->base + 2 * chan->channel + 1;
if (quadrature_mode)
mode_cfg |= (priv->quadrature_scale[chan->channel] + 1) << 3;
else {
/* Quadrature scaling only available in quadrature mode */
priv->quadrature_scale[chan->channel] = 0;
/* Synchronous function not supported in non-quadrature mode */
if (priv->synchronous_mode[chan->channel])
quad8_set_synchronous_mode(indio_dev, chan, 0);
}
priv->quadrature_mode[chan->channel] = quadrature_mode;
/* Load mode configuration to Counter Mode Register */
outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
return 0;
}
static int quad8_get_quadrature_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
const struct quad8_iio *const priv = iio_priv(indio_dev);
return priv->quadrature_mode[chan->channel];
}
static const struct iio_enum quad8_quadrature_mode_enum = {
.items = quad8_quadrature_modes,
.num_items = ARRAY_SIZE(quad8_quadrature_modes),
.set = quad8_set_quadrature_mode,
.get = quad8_get_quadrature_mode
};
static const char *const quad8_index_polarity_modes[] = {
"negative",
"positive"
};
static int quad8_set_index_polarity(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, unsigned int index_polarity)
{
struct quad8_iio *const priv = iio_priv(indio_dev);
const unsigned int idr_cfg = priv->synchronous_mode[chan->channel] |
index_polarity << 1;
const int base_offset = priv->base + 2 * chan->channel + 1;
priv->index_polarity[chan->channel] = index_polarity;
/* Load Index Control configuration to Index Control Register */
outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
return 0;
}
static int quad8_get_index_polarity(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
const struct quad8_iio *const priv = iio_priv(indio_dev);
return priv->index_polarity[chan->channel];
}
static const struct iio_enum quad8_index_polarity_enum = {
.items = quad8_index_polarity_modes,
.num_items = ARRAY_SIZE(quad8_index_polarity_modes),
.set = quad8_set_index_polarity,
.get = quad8_get_index_polarity
};
static const struct iio_chan_spec_ext_info quad8_count_ext_info[] = {
{
.name = "preset",
.shared = IIO_SEPARATE,
.read = quad8_read_preset,
.write = quad8_write_preset
},
{
.name = "set_to_preset_on_index",
.shared = IIO_SEPARATE,
.read = quad8_read_set_to_preset_on_index,
.write = quad8_write_set_to_preset_on_index
},
IIO_ENUM("noise_error", IIO_SEPARATE, &quad8_noise_error_enum),
IIO_ENUM_AVAILABLE("noise_error", &quad8_noise_error_enum),
IIO_ENUM("count_direction", IIO_SEPARATE, &quad8_count_direction_enum),
IIO_ENUM_AVAILABLE("count_direction", &quad8_count_direction_enum),
IIO_ENUM("count_mode", IIO_SEPARATE, &quad8_count_mode_enum),
IIO_ENUM_AVAILABLE("count_mode", &quad8_count_mode_enum),
IIO_ENUM("quadrature_mode", IIO_SEPARATE, &quad8_quadrature_mode_enum),
IIO_ENUM_AVAILABLE("quadrature_mode", &quad8_quadrature_mode_enum),
{}
};
static const struct iio_chan_spec_ext_info quad8_index_ext_info[] = {
IIO_ENUM("synchronous_mode", IIO_SEPARATE,
&quad8_synchronous_mode_enum),
IIO_ENUM_AVAILABLE("synchronous_mode", &quad8_synchronous_mode_enum),
IIO_ENUM("index_polarity", IIO_SEPARATE, &quad8_index_polarity_enum),
IIO_ENUM_AVAILABLE("index_polarity", &quad8_index_polarity_enum),
{}
};
#define QUAD8_COUNT_CHAN(_chan) { \
.type = IIO_COUNT, \
.channel = (_chan), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_ENABLE) | BIT(IIO_CHAN_INFO_SCALE), \
.ext_info = quad8_count_ext_info, \
.indexed = 1 \
}
#define QUAD8_INDEX_CHAN(_chan) { \
.type = IIO_INDEX, \
.channel = (_chan), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.ext_info = quad8_index_ext_info, \
.indexed = 1 \
}
static const struct iio_chan_spec quad8_channels[] = {
QUAD8_COUNT_CHAN(0), QUAD8_INDEX_CHAN(0),
QUAD8_COUNT_CHAN(1), QUAD8_INDEX_CHAN(1),
QUAD8_COUNT_CHAN(2), QUAD8_INDEX_CHAN(2),
QUAD8_COUNT_CHAN(3), QUAD8_INDEX_CHAN(3),
QUAD8_COUNT_CHAN(4), QUAD8_INDEX_CHAN(4),
QUAD8_COUNT_CHAN(5), QUAD8_INDEX_CHAN(5),
QUAD8_COUNT_CHAN(6), QUAD8_INDEX_CHAN(6),
QUAD8_COUNT_CHAN(7), QUAD8_INDEX_CHAN(7)
};
static int quad8_probe(struct device *dev, unsigned int id)
{
struct iio_dev *indio_dev;
struct quad8_iio *priv;
int i, j;
unsigned int base_offset;
indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
if (!indio_dev)
return -ENOMEM;
if (!devm_request_region(dev, base[id], QUAD8_EXTENT,
dev_name(dev))) {
dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
base[id], base[id] + QUAD8_EXTENT);
return -EBUSY;
}
indio_dev->info = &quad8_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->num_channels = ARRAY_SIZE(quad8_channels);
indio_dev->channels = quad8_channels;
indio_dev->name = dev_name(dev);
indio_dev->dev.parent = dev;
priv = iio_priv(indio_dev);
priv->base = base[id];
/* Reset all counters and disable interrupt function */
outb(QUAD8_CHAN_OP_RESET_COUNTERS, base[id] + QUAD8_REG_CHAN_OP);
/* Set initial configuration for all counters */
for (i = 0; i < QUAD8_NUM_COUNTERS; i++) {
base_offset = base[id] + 2 * i;
/* Reset Byte Pointer */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
/* Reset Preset Register */
for (j = 0; j < 3; j++)
outb(0x00, base_offset);
/* Reset Borrow, Carry, Compare, and Sign flags */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1);
/* Reset Error flag */
outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1);
/* Binary encoding; Normal count; non-quadrature mode */
outb(QUAD8_CTR_CMR, base_offset + 1);
/* Disable A and B inputs; preset on index; FLG1 as Carry */
outb(QUAD8_CTR_IOR, base_offset + 1);
/* Disable index function; negative index polarity */
outb(QUAD8_CTR_IDR, base_offset + 1);
}
/* Enable all counters */
outb(QUAD8_CHAN_OP_ENABLE_COUNTERS, base[id] + QUAD8_REG_CHAN_OP);
return devm_iio_device_register(dev, indio_dev);
}
static struct isa_driver quad8_driver = {
.probe = quad8_probe,
.driver = {
.name = "104-quad-8"
}
};
module_isa_driver(quad8_driver, num_quad8);
MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
MODULE_DESCRIPTION("ACCES 104-QUAD-8 IIO driver");
MODULE_LICENSE("GPL v2");