Loading...
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(®->in0_7) & (mask >> IDIO_16_NOUT));
35
36 if (offset < 32)
37 return !!(ioread8(®->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(®->in0_7), 16);
65 if (*mask & GENMASK(31, 24))
66 bitmap_set_value8(bits, ioread8(®->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), ®->out0_7);
95 else
96 iowrite8(bitmap_get_value8(state->out_state, 8), ®->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), ®->out0_7);
124 if (*mask & GENMASK(15, 8))
125 iowrite8(bitmap_get_value8(state->out_state, 8), ®->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");
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/bits.h>
7#include <linux/device.h>
8#include <linux/err.h>
9#include <linux/export.h>
10#include <linux/gpio/regmap.h>
11#include <linux/module.h>
12#include <linux/regmap.h>
13#include <linux/types.h>
14
15#include "gpio-idio-16.h"
16
17#define DEFAULT_SYMBOL_NAMESPACE GPIO_IDIO_16
18
19#define IDIO_16_DAT_BASE 0x0
20#define IDIO_16_OUT_BASE IDIO_16_DAT_BASE
21#define IDIO_16_IN_BASE (IDIO_16_DAT_BASE + 1)
22#define IDIO_16_CLEAR_INTERRUPT 0x1
23#define IDIO_16_ENABLE_IRQ 0x2
24#define IDIO_16_DEACTIVATE_INPUT_FILTERS 0x3
25#define IDIO_16_DISABLE_IRQ IDIO_16_ENABLE_IRQ
26#define IDIO_16_INTERRUPT_STATUS 0x6
27
28#define IDIO_16_NGPIO 32
29#define IDIO_16_NGPIO_PER_REG 8
30#define IDIO_16_REG_STRIDE 4
31
32struct idio_16_data {
33 struct regmap *map;
34 unsigned int irq_mask;
35};
36
37static int idio_16_handle_mask_sync(const int index, const unsigned int mask_buf_def,
38 const unsigned int mask_buf, void *const irq_drv_data)
39{
40 struct idio_16_data *const data = irq_drv_data;
41 const unsigned int prev_mask = data->irq_mask;
42 int err;
43 unsigned int val;
44
45 /* exit early if no change since the previous mask */
46 if (mask_buf == prev_mask)
47 return 0;
48
49 /* remember the current mask for the next mask sync */
50 data->irq_mask = mask_buf;
51
52 /* if all previously masked, enable interrupts when unmasking */
53 if (prev_mask == mask_buf_def) {
54 err = regmap_write(data->map, IDIO_16_CLEAR_INTERRUPT, 0x00);
55 if (err)
56 return err;
57 return regmap_read(data->map, IDIO_16_ENABLE_IRQ, &val);
58 }
59
60 /* if all are currently masked, disable interrupts */
61 if (mask_buf == mask_buf_def)
62 return regmap_write(data->map, IDIO_16_DISABLE_IRQ, 0x00);
63
64 return 0;
65}
66
67static int idio_16_reg_mask_xlate(struct gpio_regmap *const gpio, const unsigned int base,
68 const unsigned int offset, unsigned int *const reg,
69 unsigned int *const mask)
70{
71 unsigned int stride;
72
73 /* Input lines start at GPIO 16 */
74 if (offset < 16) {
75 stride = offset / IDIO_16_NGPIO_PER_REG;
76 *reg = IDIO_16_OUT_BASE + stride * IDIO_16_REG_STRIDE;
77 } else {
78 stride = (offset - 16) / IDIO_16_NGPIO_PER_REG;
79 *reg = IDIO_16_IN_BASE + stride * IDIO_16_REG_STRIDE;
80 }
81
82 *mask = BIT(offset % IDIO_16_NGPIO_PER_REG);
83
84 return 0;
85}
86
87static const char *idio_16_names[IDIO_16_NGPIO] = {
88 "OUT0", "OUT1", "OUT2", "OUT3", "OUT4", "OUT5", "OUT6", "OUT7",
89 "OUT8", "OUT9", "OUT10", "OUT11", "OUT12", "OUT13", "OUT14", "OUT15",
90 "IIN0", "IIN1", "IIN2", "IIN3", "IIN4", "IIN5", "IIN6", "IIN7",
91 "IIN8", "IIN9", "IIN10", "IIN11", "IIN12", "IIN13", "IIN14", "IIN15",
92};
93
94/**
95 * devm_idio_16_regmap_register - Register an IDIO-16 GPIO device
96 * @dev: device that is registering this IDIO-16 GPIO device
97 * @config: configuration for idio_16_regmap_config
98 *
99 * Registers an IDIO-16 GPIO device. Returns 0 on success and negative error number on failure.
100 */
101int devm_idio_16_regmap_register(struct device *const dev,
102 const struct idio_16_regmap_config *const config)
103{
104 struct gpio_regmap_config gpio_config = {};
105 int err;
106 struct idio_16_data *data;
107 struct regmap_irq_chip *chip;
108 struct regmap_irq_chip_data *chip_data;
109
110 if (!config->parent)
111 return -EINVAL;
112
113 if (!config->map)
114 return -EINVAL;
115
116 if (!config->regmap_irqs)
117 return -EINVAL;
118
119 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
120 if (!data)
121 return -ENOMEM;
122 data->map = config->map;
123
124 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
125 if (!chip)
126 return -ENOMEM;
127
128 chip->name = dev_name(dev);
129 chip->status_base = IDIO_16_INTERRUPT_STATUS;
130 chip->mask_base = IDIO_16_ENABLE_IRQ;
131 chip->ack_base = IDIO_16_CLEAR_INTERRUPT;
132 chip->no_status = config->no_status;
133 chip->num_regs = 1;
134 chip->irqs = config->regmap_irqs;
135 chip->num_irqs = config->num_regmap_irqs;
136 chip->handle_mask_sync = idio_16_handle_mask_sync;
137 chip->irq_drv_data = data;
138
139 /* Disable IRQ to prevent spurious interrupts before we're ready */
140 err = regmap_write(data->map, IDIO_16_DISABLE_IRQ, 0x00);
141 if (err)
142 return err;
143
144 err = devm_regmap_add_irq_chip(dev, data->map, config->irq, 0, 0, chip, &chip_data);
145 if (err)
146 return dev_err_probe(dev, err, "IRQ registration failed\n");
147
148 if (config->filters) {
149 /* Deactivate input filters */
150 err = regmap_write(data->map, IDIO_16_DEACTIVATE_INPUT_FILTERS, 0x00);
151 if (err)
152 return err;
153 }
154
155 gpio_config.parent = config->parent;
156 gpio_config.regmap = data->map;
157 gpio_config.ngpio = IDIO_16_NGPIO;
158 gpio_config.names = idio_16_names;
159 gpio_config.reg_dat_base = GPIO_REGMAP_ADDR(IDIO_16_DAT_BASE);
160 gpio_config.reg_set_base = GPIO_REGMAP_ADDR(IDIO_16_DAT_BASE);
161 gpio_config.ngpio_per_reg = IDIO_16_NGPIO_PER_REG;
162 gpio_config.reg_stride = IDIO_16_REG_STRIDE;
163 gpio_config.irq_domain = regmap_irq_get_domain(chip_data);
164 gpio_config.reg_mask_xlate = idio_16_reg_mask_xlate;
165
166 return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &gpio_config));
167}
168EXPORT_SYMBOL_GPL(devm_idio_16_regmap_register);
169
170MODULE_AUTHOR("William Breathitt Gray");
171MODULE_DESCRIPTION("ACCES IDIO-16 GPIO Library");
172MODULE_LICENSE("GPL");