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_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 output 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  * Returns the associated struct gpio_desc to the modem line gidx
  58  */
  59 struct 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 line GPIOs and set up irq
  64  * handling.
  65  * devm_* functions are used, so there's no need to call mctrl_gpio_free().
  66  * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
  67  * allocation error.
  68  */
  69 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx);
  70
  71 /*
  72  * Request and set direction of modem control line GPIOs.
  73  * devm_* functions are used, so there's no need to call mctrl_gpio_free().
  74  * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
  75  * allocation error.
  76  */
  77 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev,
  78                                            unsigned int idx);
  79
  80 /*
  81  * Free the mctrl_gpios structure.
  82  * Normally, this function will not be called, as the GPIOs will
  83  * be disposed of by the resource management code.
  84  */
  85 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
  86
  87 /*
  88  * Enable gpio interrupts to report status line changes.
  89  */
  90 void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios);
  91
  92 /*
  93  * Disable gpio interrupts to report status line changes.
  94  */
  95 void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios);
  96
  97 #else /* GPIOLIB */
  98
  99 static inline
 100 void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
 101 {
 102 }
 103
 104 static inline
 105 unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
 106 {
 107         return *mctrl;
 108 }
 109
 110 static inline
 111 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
 112                                       enum mctrl_gpio_idx gidx)
 113 {
 114         return ERR_PTR(-ENOSYS);
 115 }
 116
 117 static inline
 118 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
 119 {
 120         return ERR_PTR(-ENOSYS);
 121 }
 122
 123 static inline
 124 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
 125 {
 126         return ERR_PTR(-ENOSYS);
 127 }
 128
 129 static inline
 130 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
 131 {
 132 }
 133
 134 static inline void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
 135 {
 136 }
 137
 138 static inline void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
 139 {
 140 }
 141
 142 #endif /* GPIOLIB */
 143
 144 #endif