drivers/tty/serial/serial_mctrl_gpio.h

   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_OUT1,
  36         UART_GPIO_OUT2,
  37         UART_GPIO_MAX,
  38 };
  39
  40 /*
  41  * Opaque descriptor for modem lines controlled by GPIOs
  42  */
  43 struct mctrl_gpios;
  44
  45 #ifdef CONFIG_GPIOLIB
  46
  47 /*
  48  * Set state of the modem control output lines via GPIOs.
  49  */
  50 void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl);
  51
  52 /*
  53  * Get state of the modem control output lines from GPIOs.
  54  * The mctrl flags are updated and returned.
  55  */
  56 unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl);
  57
  58 /*
  59  * Returns the associated struct gpio_desc to the modem line gidx
  60  */
  61 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
  62                                       enum mctrl_gpio_idx gidx);
  63
  64 /*
  65  * Request and set direction of modem control lines GPIOs and sets up irq
  66  * handling.
  67  * devm_* functions are used, so there's no need to call mctrl_gpio_free().
  68  * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
  69  * allocation error.
  70  */
  71 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx);
  72
  73 /*
  74  * Request and set direction of modem control lines GPIOs.
  75  * devm_* functions are used, so there's no need to call mctrl_gpio_free().
  76  * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
  77  * allocation error.
  78  */
  79 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev,
  80                                            unsigned int idx);
  81
  82 /*
  83  * Free the mctrl_gpios structure.
  84  * Normally, this function will not be called, as the GPIOs will
  85  * be disposed of by the resource management code.
  86  */
  87 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
  88
  89 /*
  90  * Enable gpio interrupts to report status line changes.
  91  */
  92 void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios);
  93
  94 /*
  95  * Disable gpio interrupts to report status line changes.
  96  */
  97 void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios);
  98
  99 #else /* GPIOLIB */
 100
 101 static inline
 102 void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
 103 {
 104 }
 105
 106 static inline
 107 unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
 108 {
 109         return *mctrl;
 110 }
 111
 112 static inline
 113 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
 114                                       enum mctrl_gpio_idx gidx)
 115 {
 116         return ERR_PTR(-ENOSYS);
 117 }
 118
 119 static inline
 120 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
 121 {
 122         return ERR_PTR(-ENOSYS);
 123 }
 124
 125 static inline
 126 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
 127 {
 128         return ERR_PTR(-ENOSYS);
 129 }
 130
 131 static inline
 132 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
 133 {
 134 }
 135
 136 static inline void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
 137 {
 138 }
 139
 140 static inline void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
 141 {
 142 }
 143
 144 #endif /* GPIOLIB */
 145
 146 #endif