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 /*
95  * Enable gpio wakeup interrupts to enable wake up source.
96  */
97 void mctrl_gpio_enable_irq_wake(struct mctrl_gpios *gpios);
98 
99 /*
100  * Disable gpio wakeup interrupts to enable wake up source.
101  */
102 void mctrl_gpio_disable_irq_wake(struct mctrl_gpios *gpios);
103 
104 #else /* GPIOLIB */
105 
106 static inline
107 void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
108 {
109 }
110 
111 static inline
112 unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
113 {
114 	return *mctrl;
115 }
116 
117 static inline unsigned int
118 mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl)
119 {
120 	return *mctrl;
121 }
122 
123 static inline
124 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
125 				      enum mctrl_gpio_idx gidx)
126 {
127 	return NULL;
128 }
129 
130 static inline
131 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
132 {
133 	return NULL;
134 }
135 
136 static inline
137 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
138 {
139 	return NULL;
140 }
141 
142 static inline
143 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
144 {
145 }
146 
147 static inline void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
148 {
149 }
150 
151 static inline void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
152 {
153 }
154 
155 static inline void mctrl_gpio_enable_irq_wake(struct mctrl_gpios *gpios)
156 {
157 }
158 
159 static inline void mctrl_gpio_disable_irq_wake(struct mctrl_gpios *gpios)
160 {
161 }
162 
163 #endif /* GPIOLIB */
164 
165 #endif
166