diff options
author | Richard Genoud <richard.genoud@gmail.com> | 2014-05-13 20:20:43 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-05-28 12:49:14 -0700 |
commit | 84130aace83989c1dba073ed98dad721d2060258 (patch) | |
tree | e313e54a9276328a551825f58fc867aa02f8acf1 /drivers/tty/serial/serial_mctrl_gpio.h | |
parent | fa3909320c00286c6b9d6ade16bc6d44f940379c (diff) | |
download | linux-84130aace83989c1dba073ed98dad721d2060258.tar.bz2 |
tty/serial: Add GPIOLIB helpers for controlling modem lines
This patch add some helpers to control modem lines (CTS/RTS/DSR...) via
GPIO.
This will be useful for many boards which have a serial controller that
only handle CTS/RTS pins (or even just RX/TX).
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/serial_mctrl_gpio.h')
-rw-r--r-- | drivers/tty/serial/serial_mctrl_gpio.h | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/drivers/tty/serial/serial_mctrl_gpio.h b/drivers/tty/serial/serial_mctrl_gpio.h new file mode 100644 index 000000000000..400ba0494a17 --- /dev/null +++ b/drivers/tty/serial/serial_mctrl_gpio.h @@ -0,0 +1,110 @@ +/* + * Helpers for controlling modem lines via GPIO + * + * Copyright (C) 2014 Paratronic S.A. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#ifndef __SERIAL_MCTRL_GPIO__ +#define __SERIAL_MCTRL_GPIO__ + +#include <linux/err.h> +#include <linux/device.h> +#include <linux/gpio/consumer.h> + +enum mctrl_gpio_idx { + UART_GPIO_CTS, + UART_GPIO_DSR, + UART_GPIO_DCD, + UART_GPIO_RNG, + UART_GPIO_RI = UART_GPIO_RNG, + UART_GPIO_RTS, + UART_GPIO_DTR, + UART_GPIO_OUT1, + UART_GPIO_OUT2, + UART_GPIO_MAX, +}; + +/* + * Opaque descriptor for modem lines controlled by GPIOs + */ +struct mctrl_gpios; + +#ifdef CONFIG_GPIOLIB + +/* + * Set state of the modem control output lines via GPIOs. + */ +void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl); + +/* + * Get state of the modem control output lines from GPIOs. + * The mctrl flags are updated and returned. + */ +unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl); + +/* + * Returns the associated struct gpio_desc to the modem line gidx + */ +struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios, + enum mctrl_gpio_idx gidx); + +/* + * Request and set direction of modem control lines GPIOs. + * devm_* functions are used, so there's no need to call mctrl_gpio_free(). + * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on + * allocation error. + */ +struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx); + +/* + * Free the mctrl_gpios structure. + * Normally, this function will not be called, as the GPIOs will + * be disposed of by the resource management code. + */ +void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios); + +#else /* GPIOLIB */ + +static inline +void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl) +{ +} + +static inline +unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl) +{ + return *mctrl; +} + +static inline +struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios, + enum mctrl_gpio_idx gidx) +{ + return ERR_PTR(-ENOSYS); +} + +static inline +struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx) +{ + return ERR_PTR(-ENOSYS); +} + +static inline +void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios) +{ +} + +#endif /* GPIOLIB */ + +#endif |