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 input 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 * Get state of the modem control output lines from GPIOs. 58 * The mctrl flags are updated and returned. 59 */ 60 unsigned int 61 mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl); 62 63 /* 64 * Returns the associated struct gpio_desc to the modem line gidx 65 */ 66 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios, 67 enum mctrl_gpio_idx gidx); 68 69 /* 70 * Request and set direction of modem control line GPIOs and set up irq 71 * handling. 72 * devm_* functions are used, so there's no need to call mctrl_gpio_free(). 73 * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on 74 * allocation error. 75 */ 76 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx); 77 78 /* 79 * Request and set direction of modem control line GPIOs. 80 * devm_* functions are used, so there's no need to call mctrl_gpio_free(). 81 * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on 82 * allocation error. 83 */ 84 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, 85 unsigned int idx); 86 87 /* 88 * Free the mctrl_gpios structure. 89 * Normally, this function will not be called, as the GPIOs will 90 * be disposed of by the resource management code. 91 */ 92 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios); 93 94 /* 95 * Enable gpio interrupts to report status line changes. 96 */ 97 void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios); 98 99 /* 100 * Disable gpio interrupts to report status line changes. 101 */ 102 void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios); 103 104 #else /* GPIOLIB */ 105 106 static inline 107 void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl) 108 { 109 } 110 111 static inline 112 unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl) 113 { 114 return *mctrl; 115 } 116 117 static inline unsigned int 118 mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl) 119 { 120 return *mctrl; 121 } 122 123 static inline 124 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios, 125 enum mctrl_gpio_idx gidx) 126 { 127 return ERR_PTR(-ENOSYS); 128 } 129 130 static inline 131 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx) 132 { 133 return ERR_PTR(-ENOSYS); 134 } 135 136 static inline 137 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx) 138 { 139 return ERR_PTR(-ENOSYS); 140 } 141 142 static inline 143 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios) 144 { 145 } 146 147 static inline void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios) 148 { 149 } 150 151 static inline void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios) 152 { 153 } 154 155 #endif /* GPIOLIB */ 156 157 #endif 158