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
25 struct uart_port;
26
27 enum mctrl_gpio_idx {
28 UART_GPIO_CTS,
29 UART_GPIO_DSR,
30 UART_GPIO_DCD,
31 UART_GPIO_RNG,
32 UART_GPIO_RI = UART_GPIO_RNG,
33 UART_GPIO_RTS,
34 UART_GPIO_DTR,
35 UART_GPIO_MAX,
36 };
37
38 /*
39 * Opaque descriptor for modem lines controlled by GPIOs
40 */
41 struct mctrl_gpios;
42
43 #ifdef CONFIG_GPIOLIB
44
45 /*
46 * Set state of the modem control output lines via GPIOs.
47 */
48 void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl);
49
50 /*
51 * Get state of the modem control input lines from GPIOs.
52 * The mctrl flags are updated and returned.
53 */
54 unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl);
55
56 /*
57 * Get state of the modem control output lines from GPIOs.
58 * The mctrl flags are updated and returned.
59 */
60 unsigned int
61 mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl);
62
63 /*
64 * Returns the associated struct gpio_desc to the modem line gidx
65 */
66 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
67 enum mctrl_gpio_idx gidx);
68
69 /*
70 * Request and set direction of modem control line GPIOs and set up irq
71 * handling.
72 * devm_* functions are used, so there's no need to call mctrl_gpio_free().
73 * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
74 * allocation error.
75 */
76 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx);
77
78 /*
79 * Request and set direction of modem control line GPIOs.
80 * devm_* functions are used, so there's no need to call mctrl_gpio_free().
81 * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
82 * allocation error.
83 */
84 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev,
85 unsigned int idx);
86
87 /*
88 * Free the mctrl_gpios structure.
89 * Normally, this function will not be called, as the GPIOs will
90 * be disposed of by the resource management code.
91 */
92 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
93
94 /*
95 * Enable gpio interrupts to report status line changes.
96 */
97 void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios);
98
99 /*
100 * Disable gpio interrupts to report status line changes.
101 */
102 void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios);
103
104 #else /* GPIOLIB */
105
106 static inline
mctrl_gpio_set(struct mctrl_gpios * gpios,unsigned int mctrl)107 void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
108 {
109 }
110
111 static inline
mctrl_gpio_get(struct mctrl_gpios * gpios,unsigned int * mctrl)112 unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
113 {
114 return *mctrl;
115 }
116
117 static inline unsigned int
mctrl_gpio_get_outputs(struct mctrl_gpios * gpios,unsigned int * mctrl)118 mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl)
119 {
120 return *mctrl;
121 }
122
123 static inline
mctrl_gpio_to_gpiod(struct mctrl_gpios * gpios,enum mctrl_gpio_idx gidx)124 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
125 enum mctrl_gpio_idx gidx)
126 {
127 return ERR_PTR(-ENOSYS);
128 }
129
130 static inline
mctrl_gpio_init(struct uart_port * port,unsigned int idx)131 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
132 {
133 return ERR_PTR(-ENOSYS);
134 }
135
136 static inline
mctrl_gpio_init_noauto(struct device * dev,unsigned int idx)137 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
138 {
139 return ERR_PTR(-ENOSYS);
140 }
141
142 static inline
mctrl_gpio_free(struct device * dev,struct mctrl_gpios * gpios)143 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
144 {
145 }
146
mctrl_gpio_enable_ms(struct mctrl_gpios * gpios)147 static inline void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
148 {
149 }
150
mctrl_gpio_disable_ms(struct mctrl_gpios * gpios)151 static inline void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
152 {
153 }
154
155 #endif /* GPIOLIB */
156
157 #endif
158