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 147