summaryrefslogtreecommitdiff
path: root/drivers/tty/serial/serial_mctrl_gpio.c
blob: a38596c5194e4b6f6a1feb26183e4b9cd8366f2f (plain) (blame)
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
/*
 * Helpers for controlling modem lines via GPIO
 *
 * Copyright (C) 2014 Paratronic S.A.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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.
 *
 */

#include <linux/err.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/termios.h>

#include "serial_mctrl_gpio.h"

struct mctrl_gpios {
	struct gpio_desc *gpio[UART_GPIO_MAX];
};

static const struct {
	const char *name;
	unsigned int mctrl;
	bool dir_out;
} mctrl_gpios_desc[UART_GPIO_MAX] = {
	{ "cts", TIOCM_CTS, false, },
	{ "dsr", TIOCM_DSR, false, },
	{ "dcd", TIOCM_CD, false, },
	{ "rng", TIOCM_RNG, false, },
	{ "rts", TIOCM_RTS, true, },
	{ "dtr", TIOCM_DTR, true, },
	{ "out1", TIOCM_OUT1, true, },
	{ "out2", TIOCM_OUT2, true, },
};

void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
{
	enum mctrl_gpio_idx i;
	struct gpio_desc *desc_array[UART_GPIO_MAX];
	int value_array[UART_GPIO_MAX];
	unsigned int count = 0;

	if (IS_ERR_OR_NULL(gpios))
		return;

	for (i = 0; i < UART_GPIO_MAX; i++)
		if (!IS_ERR_OR_NULL(gpios->gpio[i]) &&
		    mctrl_gpios_desc[i].dir_out) {
			desc_array[count] = gpios->gpio[i];
			value_array[count] = !!(mctrl & mctrl_gpios_desc[i].mctrl);
			count++;
		}
	gpiod_set_array(count, desc_array, value_array);
}
EXPORT_SYMBOL_GPL(mctrl_gpio_set);

struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
				      enum mctrl_gpio_idx gidx)
{
	if (!IS_ERR_OR_NULL(gpios) && !IS_ERR_OR_NULL(gpios->gpio[gidx]))
		return gpios->gpio[gidx];
	else
		return NULL;
}
EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod);

unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
{
	enum mctrl_gpio_idx i;

	/*
	 * return it unchanged if the structure is not allocated
	 */
	if (IS_ERR_OR_NULL(gpios))
		return *mctrl;

	for (i = 0; i < UART_GPIO_MAX; i++) {
		if (!IS_ERR_OR_NULL(gpios->gpio[i]) &&
		    !mctrl_gpios_desc[i].dir_out) {
			if (gpiod_get_value(gpios->gpio[i]))
				*mctrl |= mctrl_gpios_desc[i].mctrl;
			else
				*mctrl &= ~mctrl_gpios_desc[i].mctrl;
		}
	}

	return *mctrl;
}
EXPORT_SYMBOL_GPL(mctrl_gpio_get);

struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx)
{
	struct mctrl_gpios *gpios;
	enum mctrl_gpio_idx i;
	int err;

	gpios = devm_kzalloc(dev, sizeof(*gpios), GFP_KERNEL);
	if (!gpios)
		return ERR_PTR(-ENOMEM);

	for (i = 0; i < UART_GPIO_MAX; i++) {
		gpios->gpio[i] = devm_gpiod_get_index(dev,
						      mctrl_gpios_desc[i].name,
						      idx);

		/*
		 * The GPIOs are maybe not all filled,
		 * this is not an error.
		 */
		if (IS_ERR_OR_NULL(gpios->gpio[i]))
			continue;

		if (mctrl_gpios_desc[i].dir_out)
			err = gpiod_direction_output(gpios->gpio[i], 0);
		else
			err = gpiod_direction_input(gpios->gpio[i]);
		if (err) {
			dev_dbg(dev, "Unable to set direction for %s GPIO",
				mctrl_gpios_desc[i].name);
			devm_gpiod_put(dev, gpios->gpio[i]);
			gpios->gpio[i] = NULL;
		}
	}

	return gpios;
}
EXPORT_SYMBOL_GPL(mctrl_gpio_init);

void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
{
	enum mctrl_gpio_idx i;

	if (IS_ERR_OR_NULL(gpios))
		return;

	for (i = 0; i < UART_GPIO_MAX; i++)
		if (!IS_ERR_OR_NULL(gpios->gpio[i]))
			devm_gpiod_put(dev, gpios->gpio[i]);
	devm_kfree(dev, gpios);
}
EXPORT_SYMBOL_GPL(mctrl_gpio_free);