summaryrefslogtreecommitdiff
path: root/drivers/gpio/gpio-xra1403.c
blob: e2cac12092afa9d06eec52f2e7bf92a8dcac2d34 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
// SPDX-License-Identifier: GPL-2.0-only
/*
 * GPIO driver for EXAR XRA1403 16-bit GPIO expander
 *
 * Copyright (c) 2017, General Electric Company
 */

#include <linux/bitops.h>
#include <linux/gpio/driver.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/seq_file.h>
#include <linux/spi/spi.h>
#include <linux/regmap.h>

/* XRA1403 registers */
#define XRA_GSR   0x00 /* GPIO State */
#define XRA_OCR   0x02 /* Output Control */
#define XRA_PIR   0x04 /* Input Polarity Inversion */
#define XRA_GCR   0x06 /* GPIO Configuration */
#define XRA_PUR   0x08 /* Input Internal Pull-up Resistor Enable/Disable */
#define XRA_IER   0x0A /* Input Interrupt Enable */
#define XRA_TSCR  0x0C /* Output Three-State Control */
#define XRA_ISR   0x0E /* Input Interrupt Status */
#define XRA_REIR  0x10 /* Input Rising Edge Interrupt Enable */
#define XRA_FEIR  0x12 /* Input Falling Edge Interrupt Enable */
#define XRA_IFR   0x14 /* Input Filter Enable/Disable */
#define XRA_LAST  0x15 /* Bounds */

struct xra1403 {
	struct gpio_chip  chip;
	struct regmap     *regmap;
};

static const struct regmap_config xra1403_regmap_cfg = {
		.reg_bits = 7,
		.pad_bits = 1,
		.val_bits = 8,

		.max_register = XRA_LAST,
};

static unsigned int to_reg(unsigned int reg, unsigned int offset)
{
	return reg + (offset > 7);
}

static int xra1403_direction_input(struct gpio_chip *chip, unsigned int offset)
{
	struct xra1403 *xra = gpiochip_get_data(chip);

	return regmap_update_bits(xra->regmap, to_reg(XRA_GCR, offset),
			BIT(offset % 8), BIT(offset % 8));
}

static int xra1403_direction_output(struct gpio_chip *chip, unsigned int offset,
				    int value)
{
	int ret;
	struct xra1403 *xra = gpiochip_get_data(chip);

	ret = regmap_update_bits(xra->regmap, to_reg(XRA_GCR, offset),
			BIT(offset % 8), 0);
	if (ret)
		return ret;

	ret = regmap_update_bits(xra->regmap, to_reg(XRA_OCR, offset),
			BIT(offset % 8), value ? BIT(offset % 8) : 0);

	return ret;
}

static int xra1403_get_direction(struct gpio_chip *chip, unsigned int offset)
{
	int ret;
	unsigned int val;
	struct xra1403 *xra = gpiochip_get_data(chip);

	ret = regmap_read(xra->regmap, to_reg(XRA_GCR, offset), &val);
	if (ret)
		return ret;

	if (val & BIT(offset % 8))
		return GPIO_LINE_DIRECTION_IN;

	return GPIO_LINE_DIRECTION_OUT;
}

static int xra1403_get(struct gpio_chip *chip, unsigned int offset)
{
	int ret;
	unsigned int val;
	struct xra1403 *xra = gpiochip_get_data(chip);

	ret = regmap_read(xra->regmap, to_reg(XRA_GSR, offset), &val);
	if (ret)
		return ret;

	return !!(val & BIT(offset % 8));
}

static void xra1403_set(struct gpio_chip *chip, unsigned int offset, int value)
{
	int ret;
	struct xra1403 *xra = gpiochip_get_data(chip);

	ret = regmap_update_bits(xra->regmap, to_reg(XRA_OCR, offset),
			BIT(offset % 8), value ? BIT(offset % 8) : 0);
	if (ret)
		dev_err(chip->parent, "Failed to set pin: %d, ret: %d\n",
				offset, ret);
}

#ifdef CONFIG_DEBUG_FS
static void xra1403_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
	int reg;
	struct xra1403 *xra = gpiochip_get_data(chip);
	int value[XRA_LAST];
	int i;
	const char *label;
	unsigned int gcr;
	unsigned int gsr;

	seq_puts(s, "xra reg:");
	for (reg = 0; reg <= XRA_LAST; reg++)
		seq_printf(s, " %2.2x", reg);
	seq_puts(s, "\n  value:");
	for (reg = 0; reg < XRA_LAST; reg++) {
		regmap_read(xra->regmap, reg, &value[reg]);
		seq_printf(s, " %2.2x", value[reg]);
	}
	seq_puts(s, "\n");

	gcr = value[XRA_GCR + 1] << 8 | value[XRA_GCR];
	gsr = value[XRA_GSR + 1] << 8 | value[XRA_GSR];
	for_each_requested_gpio(chip, i, label) {
		seq_printf(s, " gpio-%-3d (%-12s) %s %s\n",
			   chip->base + i, label,
			   (gcr & BIT(i)) ? "in" : "out",
			   (gsr & BIT(i)) ? "hi" : "lo");
	}
}
#else
#define xra1403_dbg_show NULL
#endif

static int xra1403_probe(struct spi_device *spi)
{
	struct xra1403 *xra;
	struct gpio_desc *reset_gpio;
	int ret;

	xra = devm_kzalloc(&spi->dev, sizeof(*xra), GFP_KERNEL);
	if (!xra)
		return -ENOMEM;

	/* bring the chip out of reset if reset pin is provided*/
	reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_LOW);
	if (IS_ERR(reset_gpio))
		dev_warn(&spi->dev, "Could not get reset-gpios\n");

	xra->chip.direction_input = xra1403_direction_input;
	xra->chip.direction_output = xra1403_direction_output;
	xra->chip.get_direction = xra1403_get_direction;
	xra->chip.get = xra1403_get;
	xra->chip.set = xra1403_set;

	xra->chip.dbg_show = xra1403_dbg_show;

	xra->chip.ngpio = 16;
	xra->chip.label = "xra1403";

	xra->chip.base = -1;
	xra->chip.can_sleep = true;
	xra->chip.parent = &spi->dev;
	xra->chip.owner = THIS_MODULE;

	xra->regmap = devm_regmap_init_spi(spi, &xra1403_regmap_cfg);
	if (IS_ERR(xra->regmap)) {
		ret = PTR_ERR(xra->regmap);
		dev_err(&spi->dev, "Failed to allocate regmap: %d\n", ret);
		return ret;
	}

	ret = devm_gpiochip_add_data(&spi->dev, &xra->chip, xra);
	if (ret < 0) {
		dev_err(&spi->dev, "Unable to register gpiochip\n");
		return ret;
	}

	spi_set_drvdata(spi, xra);

	return 0;
}

static const struct spi_device_id xra1403_ids[] = {
	{ "xra1403" },
	{},
};
MODULE_DEVICE_TABLE(spi, xra1403_ids);

static const struct of_device_id xra1403_spi_of_match[] = {
	{ .compatible = "exar,xra1403" },
	{},
};
MODULE_DEVICE_TABLE(of, xra1403_spi_of_match);

static struct spi_driver xra1403_driver = {
	.probe    = xra1403_probe,
	.id_table = xra1403_ids,
	.driver   = {
		.name           = "xra1403",
		.of_match_table = of_match_ptr(xra1403_spi_of_match),
	},
};

module_spi_driver(xra1403_driver);

MODULE_AUTHOR("Nandor Han <nandor.han@ge.com>");
MODULE_AUTHOR("Semi Malinen <semi.malinen@ge.com>");
MODULE_DESCRIPTION("GPIO expander driver for EXAR XRA1403");
MODULE_LICENSE("GPL v2");