1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * Helpers for controlling modem lines via GPIO
4 *
5 * Copyright (C) 2014 Paratronic S.A.
6 */
7
8 #ifndef __SERIAL_MCTRL_GPIO__
9 #define __SERIAL_MCTRL_GPIO__
10
11 #include <linux/err.h>
12 #include <linux/device.h>
13 #include <linux/gpio/consumer.h>
14
15 struct uart_port;
16
17 enum mctrl_gpio_idx {
18 UART_GPIO_CTS,
19 UART_GPIO_DSR,
20 UART_GPIO_DCD,
21 UART_GPIO_RNG,
22 UART_GPIO_RI = UART_GPIO_RNG,
23 UART_GPIO_RTS,
24 UART_GPIO_DTR,
25 UART_GPIO_MAX,
26 };
27
28 /*
29 * Opaque descriptor for modem lines controlled by GPIOs
30 */
31 struct mctrl_gpios;
32
33 #ifdef CONFIG_GPIOLIB
34
35 /*
36 * Set state of the modem control output lines via GPIOs.
37 */
38 void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl);
39
40 /*
41 * Get state of the modem control input lines from GPIOs.
42 * The mctrl flags are updated and returned.
43 */
44 unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl);
45
46 /*
47 * Get state of the modem control output lines from GPIOs.
48 * The mctrl flags are updated and returned.
49 */
50 unsigned int
51 mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl);
52
53 /*
54 * Returns the associated struct gpio_desc to the modem line gidx
55 */
56 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
57 enum mctrl_gpio_idx gidx);
58
59 /*
60 * Request and set direction of modem control line GPIOs and set up irq
61 * handling.
62 * devm_* functions are used, so there's no need to call mctrl_gpio_free().
63 * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
64 * allocation error.
65 */
66 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx);
67
68 /*
69 * Request and set direction of modem control line GPIOs.
70 * devm_* functions are used, so there's no need to call mctrl_gpio_free().
71 * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
72 * allocation error.
73 */
74 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev,
75 unsigned int idx);
76
77 /*
78 * Free the mctrl_gpios structure.
79 * Normally, this function will not be called, as the GPIOs will
80 * be disposed of by the resource management code.
81 */
82 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
83
84 /*
85 * Enable gpio interrupts to report status line changes.
86 */
87 void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios);
88
89 /*
90 * Disable gpio interrupts to report status line changes.
91 */
92 void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios);
93
94 #else /* GPIOLIB */
95
96 static inline
mctrl_gpio_set(struct mctrl_gpios * gpios,unsigned int mctrl)97 void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
98 {
99 }
100
101 static inline
mctrl_gpio_get(struct mctrl_gpios * gpios,unsigned int * mctrl)102 unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
103 {
104 return *mctrl;
105 }
106
107 static inline unsigned int
mctrl_gpio_get_outputs(struct mctrl_gpios * gpios,unsigned int * mctrl)108 mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl)
109 {
110 return *mctrl;
111 }
112
113 static inline
mctrl_gpio_to_gpiod(struct mctrl_gpios * gpios,enum mctrl_gpio_idx gidx)114 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
115 enum mctrl_gpio_idx gidx)
116 {
117 return NULL;
118 }
119
120 static inline
mctrl_gpio_init(struct uart_port * port,unsigned int idx)121 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
122 {
123 return NULL;
124 }
125
126 static inline
mctrl_gpio_init_noauto(struct device * dev,unsigned int idx)127 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
128 {
129 return NULL;
130 }
131
132 static inline
mctrl_gpio_free(struct device * dev,struct mctrl_gpios * gpios)133 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
134 {
135 }
136
mctrl_gpio_enable_ms(struct mctrl_gpios * gpios)137 static inline void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
138 {
139 }
140
mctrl_gpio_disable_ms(struct mctrl_gpios * gpios)141 static inline void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
142 {
143 }
144
145 #endif /* GPIOLIB */
146
147 #endif
148
