LXR linux/drivers/tty/serial/serial_mctrl

   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
  15struct uart_port;
  16
  17enum 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 */
  31struct mctrl_gpios;
  32
  33#ifdef CONFIG_GPIOLIB
  34
  35/*
  36 * Set state of the modem control output lines via GPIOs.
  37 */
  38void 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 */
  44unsigned 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 */
  50unsigned int
  51mctrl_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 */
  56struct 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 */
  66struct 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 */
  74struct 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 */
  82void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
  83
  84/*
  85 * Enable gpio interrupts to report status line changes.
  86 */
  87void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios);
  88
  89/*
  90 * Disable gpio interrupts to report status line changes.
  91 */
  92void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios);
  93
  94#else /* GPIOLIB */
  95
  96static inline
  97void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
  98{
  99}
 100
 101static inline
 102unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
 103{
 104        return *mctrl;
 105}
 106
 107static inline unsigned int
 108mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl)
 109{
 110        return *mctrl;
 111}
 112
 113static inline
 114struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
 115                                      enum mctrl_gpio_idx gidx)
 116{
 117        return NULL;
 118}
 119
 120static inline
 121struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
 122{
 123        return NULL;
 124}
 125
 126static inline
 127struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
 128{
 129        return NULL;
 130}
 131
 132static inline
 133void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
 134{
 135}
 136
 137static inline void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
 138{
 139}
 140
 141static inline void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
 142{
 143}
 144
 145#endif /* GPIOLIB */
 146
 147#endif
 148