linux/drivers/gpio/gpio-idio-16.c
William Breathitt Gray b9b1fc1ae1 gpio: idio-16: Introduce the ACCES IDIO-16 GPIO library module
Exposes consumer library functions to facilitate communication with
devices within the ACCES IDIO-16 family such as the 104-IDIO-16 and
the PCI-IDIO-16.

A CONFIG_GPIO_IDIO_16 Kconfig option is introduced by this patch.
Modules wanting access to these idio-16 library functions should select
this Kconfig option and import the GPIO_IDIO_16 symbol namespace.

Cc: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2022-10-25 09:56:46 +02:00

147 lines
4.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* GPIO library for the ACCES IDIO-16 family
* Copyright (C) 2022 William Breathitt Gray
*/
#include <linux/bitmap.h>
#include <linux/export.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include "gpio-idio-16.h"
#define DEFAULT_SYMBOL_NAMESPACE GPIO_IDIO_16
/**
* idio_16_get - get signal value at signal offset
* @reg: ACCES IDIO-16 device registers
* @state: ACCES IDIO-16 device state
* @offset: offset of signal to get
*
* Returns the signal value (0=low, 1=high) for the signal at @offset.
*/
int idio_16_get(struct idio_16 __iomem *const reg,
struct idio_16_state *const state, const unsigned long offset)
{
const unsigned long mask = BIT(offset);
if (offset < IDIO_16_NOUT)
return test_bit(offset, state->out_state);
if (offset < 24)
return !!(ioread8(&reg->in0_7) & (mask >> IDIO_16_NOUT));
if (offset < 32)
return !!(ioread8(&reg->in8_15) & (mask >> 24));
return -EINVAL;
}
EXPORT_SYMBOL_GPL(idio_16_get);
/**
* idio_16_get_multiple - get multiple signal values at multiple signal offsets
* @reg: ACCES IDIO-16 device registers
* @state: ACCES IDIO-16 device state
* @mask: mask of signals to get
* @bits: bitmap to store signal values
*
* Stores in @bits the values (0=low, 1=high) for the signals defined by @mask.
*/
void idio_16_get_multiple(struct idio_16 __iomem *const reg,
struct idio_16_state *const state,
const unsigned long *const mask,
unsigned long *const bits)
{
unsigned long flags;
const unsigned long out_mask = GENMASK(IDIO_16_NOUT - 1, 0);
spin_lock_irqsave(&state->lock, flags);
bitmap_replace(bits, bits, state->out_state, &out_mask, IDIO_16_NOUT);
if (*mask & GENMASK(23, 16))
bitmap_set_value8(bits, ioread8(&reg->in0_7), 16);
if (*mask & GENMASK(31, 24))
bitmap_set_value8(bits, ioread8(&reg->in8_15), 24);
spin_unlock_irqrestore(&state->lock, flags);
}
EXPORT_SYMBOL_GPL(idio_16_get_multiple);
/**
* idio_16_set - set signal value at signal offset
* @reg: ACCES IDIO-16 device registers
* @state: ACCES IDIO-16 device state
* @offset: offset of signal to set
* @value: value of signal to set
*
* Assigns output @value for the signal at @offset.
*/
void idio_16_set(struct idio_16 __iomem *const reg,
struct idio_16_state *const state, const unsigned long offset,
const unsigned long value)
{
unsigned long flags;
if (offset >= IDIO_16_NOUT)
return;
spin_lock_irqsave(&state->lock, flags);
__assign_bit(offset, state->out_state, value);
if (offset < 8)
iowrite8(bitmap_get_value8(state->out_state, 0), &reg->out0_7);
else
iowrite8(bitmap_get_value8(state->out_state, 8), &reg->out8_15);
spin_unlock_irqrestore(&state->lock, flags);
}
EXPORT_SYMBOL_GPL(idio_16_set);
/**
* idio_16_set_multiple - set signal values at multiple signal offsets
* @reg: ACCES IDIO-16 device registers
* @state: ACCES IDIO-16 device state
* @mask: mask of signals to set
* @bits: bitmap of signal output values
*
* Assigns output values defined by @bits for the signals defined by @mask.
*/
void idio_16_set_multiple(struct idio_16 __iomem *const reg,
struct idio_16_state *const state,
const unsigned long *const mask,
const unsigned long *const bits)
{
unsigned long flags;
spin_lock_irqsave(&state->lock, flags);
bitmap_replace(state->out_state, state->out_state, bits, mask,
IDIO_16_NOUT);
if (*mask & GENMASK(7, 0))
iowrite8(bitmap_get_value8(state->out_state, 0), &reg->out0_7);
if (*mask & GENMASK(15, 8))
iowrite8(bitmap_get_value8(state->out_state, 8), &reg->out8_15);
spin_unlock_irqrestore(&state->lock, flags);
}
EXPORT_SYMBOL_GPL(idio_16_set_multiple);
/**
* idio_16_state_init - initialize idio_16_state structure
* @state: ACCES IDIO-16 device state
*
* Initializes the ACCES IDIO-16 device @state for use in idio-16 library
* functions.
*/
void idio_16_state_init(struct idio_16_state *const state)
{
spin_lock_init(&state->lock);
}
EXPORT_SYMBOL_GPL(idio_16_state_init);
MODULE_AUTHOR("William Breathitt Gray");
MODULE_DESCRIPTION("ACCES IDIO-16 GPIO Library");
MODULE_LICENSE("GPL");