1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * Helpers for controlling modem lines via GPIO 4 * 5 * Copyright (C) 2014 Paratronic S.A. 6 */ 7 8 #ifndef __SERIAL_MCTRL_GPIO__ 9 #define __SERIAL_MCTRL_GPIO__ 10 11 #include <linux/err.h> 12 #include <linux/device.h> 13 #include <linux/gpio/consumer.h> 14 15 struct uart_port; 16 17 enum mctrl_gpio_idx { 18 UART_GPIO_CTS, 19 UART_GPIO_DSR, 20 UART_GPIO_DCD, 21 UART_GPIO_RNG, 22 UART_GPIO_RI = UART_GPIO_RNG, 23 UART_GPIO_RTS, 24 UART_GPIO_DTR, 25 UART_GPIO_MAX, 26 }; 27 28 /* 29 * Opaque descriptor for modem lines controlled by GPIOs 30 */ 31 struct mctrl_gpios; 32 33 #ifdef CONFIG_GPIOLIB 34 35 /* 36 * Set state of the modem control output lines via GPIOs. 37 */ 38 void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl); 39 40 /* 41 * Get state of the modem control input lines from GPIOs. 42 * The mctrl flags are updated and returned. 43 */ 44 unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl); 45 46 /* 47 * Get state of the modem control output lines from GPIOs. 48 * The mctrl flags are updated and returned. 49 */ 50 unsigned int 51 mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl); 52 53 /* 54 * Returns the associated struct gpio_desc to the modem line gidx 55 */ 56 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios, 57 enum mctrl_gpio_idx gidx); 58 59 /* 60 * Request and set direction of modem control line GPIOs and set up irq 61 * handling. 62 * devm_* functions are used, so there's no need to call mctrl_gpio_free(). 63 * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on 64 * allocation error. 65 */ 66 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx); 67 68 /* 69 * Request and set direction of modem control line GPIOs. 70 * devm_* functions are used, so there's no need to call mctrl_gpio_free(). 71 * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on 72 * allocation error. 73 */ 74 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, 75 unsigned int idx); 76 77 /* 78 * Free the mctrl_gpios structure. 79 * Normally, this function will not be called, as the GPIOs will 80 * be disposed of by the resource management code. 81 */ 82 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios); 83 84 /* 85 * Enable gpio interrupts to report status line changes. 86 */ 87 void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios); 88 89 /* 90 * Disable gpio interrupts to report status line changes. 91 */ 92 void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios); 93 94 #else /* GPIOLIB */ 95 96 static inline 97 void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl) 98 { 99 } 100 101 static inline 102 unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl) 103 { 104 return *mctrl; 105 } 106 107 static inline unsigned int 108 mctrl_gpio_get_outputs(struct mctrl_gpios *gpios, unsigned int *mctrl) 109 { 110 return *mctrl; 111 } 112 113 static inline 114 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios, 115 enum mctrl_gpio_idx gidx) 116 { 117 return NULL; 118 } 119 120 static inline 121 struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx) 122 { 123 return NULL; 124 } 125 126 static inline 127 struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx) 128 { 129 return NULL; 130 } 131 132 static inline 133 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios) 134 { 135 } 136 137 static inline void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios) 138 { 139 } 140 141 static inline void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios) 142 { 143 } 144 145 #endif /* GPIOLIB */ 146 147 #endif 148