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 145