1/*
2 * Helpers for controlling modem lines via GPIO
3 *
4 * Copyright (C) 2014 Paratronic S.A.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 */
17
18#ifndef __SERIAL_MCTRL_GPIO__
19#define __SERIAL_MCTRL_GPIO__
20
21#include <linux/err.h>
22#include <linux/device.h>
23#include <linux/gpio/consumer.h>
24
25enum mctrl_gpio_idx {
26	UART_GPIO_CTS,
27	UART_GPIO_DSR,
28	UART_GPIO_DCD,
29	UART_GPIO_RNG,
30	UART_GPIO_RI = UART_GPIO_RNG,
31	UART_GPIO_RTS,
32	UART_GPIO_DTR,
33	UART_GPIO_OUT1,
34	UART_GPIO_OUT2,
35	UART_GPIO_MAX,
36};
37
38/*
39 * Opaque descriptor for modem lines controlled by GPIOs
40 */
41struct mctrl_gpios;
42
43#ifdef CONFIG_GPIOLIB
44
45/*
46 * Set state of the modem control output lines via GPIOs.
47 */
48void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl);
49
50/*
51 * Get state of the modem control output lines from GPIOs.
52 * The mctrl flags are updated and returned.
53 */
54unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl);
55
56/*
57 * Returns the associated struct gpio_desc to the modem line gidx
58 */
59struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
60				      enum mctrl_gpio_idx gidx);
61
62/*
63 * Request and set direction of modem control lines GPIOs.
64 * devm_* functions are used, so there's no need to call mctrl_gpio_free().
65 * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
66 * allocation error.
67 */
68struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx);
69
70/*
71 * Free the mctrl_gpios structure.
72 * Normally, this function will not be called, as the GPIOs will
73 * be disposed of by the resource management code.
74 */
75void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
76
77#else /* GPIOLIB */
78
79static inline
80void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
81{
82}
83
84static inline
85unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
86{
87	return *mctrl;
88}
89
90static inline
91struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
92				      enum mctrl_gpio_idx gidx)
93{
94	return ERR_PTR(-ENOSYS);
95}
96
97static inline
98struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx)
99{
100	return ERR_PTR(-ENOSYS);
101}
102
103static inline
104void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
105{
106}
107
108#endif /* GPIOLIB */
109
110#endif
111