1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * GPIO library for the ACCES IDIO-16 family
  4 * Copyright (C) 2022 William Breathitt Gray
  5 */
  6#include <linux/bitmap.h>
  7#include <linux/export.h>
  8#include <linux/io.h>
  9#include <linux/module.h>
 10#include <linux/spinlock.h>
 11#include <linux/types.h>
 12
 13#include "gpio-idio-16.h"
 14
 15#define DEFAULT_SYMBOL_NAMESPACE GPIO_IDIO_16
 16
 17/**
 18 * idio_16_get - get signal value at signal offset
 19 * @reg:	ACCES IDIO-16 device registers
 20 * @state:	ACCES IDIO-16 device state
 21 * @offset:	offset of signal to get
 22 *
 23 * Returns the signal value (0=low, 1=high) for the signal at @offset.
 24 */
 25int idio_16_get(struct idio_16 __iomem *const reg,
 26		struct idio_16_state *const state, const unsigned long offset)
 27{
 28	const unsigned long mask = BIT(offset);
 29
 30	if (offset < IDIO_16_NOUT)
 31		return test_bit(offset, state->out_state);
 32
 33	if (offset < 24)
 34		return !!(ioread8(&reg->in0_7) & (mask >> IDIO_16_NOUT));
 35
 36	if (offset < 32)
 37		return !!(ioread8(&reg->in8_15) & (mask >> 24));
 38
 39	return -EINVAL;
 40}
 41EXPORT_SYMBOL_GPL(idio_16_get);
 42
 43/**
 44 * idio_16_get_multiple - get multiple signal values at multiple signal offsets
 45 * @reg:	ACCES IDIO-16 device registers
 46 * @state:	ACCES IDIO-16 device state
 47 * @mask:	mask of signals to get
 48 * @bits:	bitmap to store signal values
 49 *
 50 * Stores in @bits the values (0=low, 1=high) for the signals defined by @mask.
 51 */
 52void idio_16_get_multiple(struct idio_16 __iomem *const reg,
 53			  struct idio_16_state *const state,
 54			  const unsigned long *const mask,
 55			  unsigned long *const bits)
 56{
 57	unsigned long flags;
 58	const unsigned long out_mask = GENMASK(IDIO_16_NOUT - 1, 0);
 59
 60	spin_lock_irqsave(&state->lock, flags);
 61
 62	bitmap_replace(bits, bits, state->out_state, &out_mask, IDIO_16_NOUT);
 63	if (*mask & GENMASK(23, 16))
 64		bitmap_set_value8(bits, ioread8(&reg->in0_7), 16);
 65	if (*mask & GENMASK(31, 24))
 66		bitmap_set_value8(bits, ioread8(&reg->in8_15), 24);
 67
 68	spin_unlock_irqrestore(&state->lock, flags);
 69}
 70EXPORT_SYMBOL_GPL(idio_16_get_multiple);
 71
 72/**
 73 * idio_16_set - set signal value at signal offset
 74 * @reg:	ACCES IDIO-16 device registers
 75 * @state:	ACCES IDIO-16 device state
 76 * @offset:	offset of signal to set
 77 * @value:	value of signal to set
 78 *
 79 * Assigns output @value for the signal at @offset.
 80 */
 81void idio_16_set(struct idio_16 __iomem *const reg,
 82		 struct idio_16_state *const state, const unsigned long offset,
 83		 const unsigned long value)
 84{
 85	unsigned long flags;
 86
 87	if (offset >= IDIO_16_NOUT)
 88		return;
 89
 90	spin_lock_irqsave(&state->lock, flags);
 91
 92	__assign_bit(offset, state->out_state, value);
 93	if (offset < 8)
 94		iowrite8(bitmap_get_value8(state->out_state, 0), &reg->out0_7);
 95	else
 96		iowrite8(bitmap_get_value8(state->out_state, 8), &reg->out8_15);
 97
 98	spin_unlock_irqrestore(&state->lock, flags);
 99}
100EXPORT_SYMBOL_GPL(idio_16_set);
101
102/**
103 * idio_16_set_multiple - set signal values at multiple signal offsets
104 * @reg:	ACCES IDIO-16 device registers
105 * @state:	ACCES IDIO-16 device state
106 * @mask:	mask of signals to set
107 * @bits:	bitmap of signal output values
108 *
109 * Assigns output values defined by @bits for the signals defined by @mask.
110 */
111void idio_16_set_multiple(struct idio_16 __iomem *const reg,
112			  struct idio_16_state *const state,
113			  const unsigned long *const mask,
114			  const unsigned long *const bits)
115{
116	unsigned long flags;
117
118	spin_lock_irqsave(&state->lock, flags);
119
120	bitmap_replace(state->out_state, state->out_state, bits, mask,
121		       IDIO_16_NOUT);
122	if (*mask & GENMASK(7, 0))
123		iowrite8(bitmap_get_value8(state->out_state, 0), &reg->out0_7);
124	if (*mask & GENMASK(15, 8))
125		iowrite8(bitmap_get_value8(state->out_state, 8), &reg->out8_15);
126
127	spin_unlock_irqrestore(&state->lock, flags);
128}
129EXPORT_SYMBOL_GPL(idio_16_set_multiple);
130
131/**
132 * idio_16_state_init - initialize idio_16_state structure
133 * @state:	ACCES IDIO-16 device state
134 *
135 * Initializes the ACCES IDIO-16 device @state for use in idio-16 library
136 * functions.
137 */
138void idio_16_state_init(struct idio_16_state *const state)
139{
140	spin_lock_init(&state->lock);
141}
142EXPORT_SYMBOL_GPL(idio_16_state_init);
143
144MODULE_AUTHOR("William Breathitt Gray");
145MODULE_DESCRIPTION("ACCES IDIO-16 GPIO Library");
146MODULE_LICENSE("GPL");