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 enum mctrl_gpio_idx { 26 UART_GPIO_CTS, 27 UART_GPIO_DSR, 28 UART_GPIO_DCD, 29 UART_GPIO_RNG, 30 UART_GPIO_RI = UART_GPIO_RNG, 31 UART_GPIO_RTS, 32 UART_GPIO_DTR, 33 UART_GPIO_OUT1, 34 UART_GPIO_OUT2, 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 lines GPIOs. 64 * devm_* functions are used, so there's no need to call mctrl_gpio_free(). 65 * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on 66 * allocation error. 67 */ 68 struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx); 69 70 /* 71 * Free the mctrl_gpios structure. 72 * Normally, this function will not be called, as the GPIOs will 73 * be disposed of by the resource management code. 74 */ 75 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios); 76 77 #else /* GPIOLIB */ 78 79 static inline 80 void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl) 81 { 82 } 83 84 static inline 85 unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl) 86 { 87 return *mctrl; 88 } 89 90 static inline 91 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios, 92 enum mctrl_gpio_idx gidx) 93 { 94 return ERR_PTR(-ENOSYS); 95 } 96 97 static inline 98 struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx) 99 { 100 return ERR_PTR(-ENOSYS); 101 } 102 103 static inline 104 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios) 105 { 106 } 107 108 #endif /* GPIOLIB */ 109 110 #endif 111