2 * Helpers for controlling modem lines via GPIO
4 * Copyright (C) 2014 Paratronic S.A.
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.
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.
18 #include <linux/err.h>
19 #include <linux/device.h>
20 #include <linux/gpio/consumer.h>
21 #include <linux/termios.h>
23 #include "serial_mctrl_gpio.h"
26 struct gpio_desc *gpio[UART_GPIO_MAX];
33 } mctrl_gpios_desc[UART_GPIO_MAX] = {
34 { "cts", TIOCM_CTS, false, },
35 { "dsr", TIOCM_DSR, false, },
36 { "dcd", TIOCM_CD, false, },
37 { "rng", TIOCM_RNG, false, },
38 { "rts", TIOCM_RTS, true, },
39 { "dtr", TIOCM_DTR, true, },
40 { "out1", TIOCM_OUT1, true, },
41 { "out2", TIOCM_OUT2, true, },
44 void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
46 enum mctrl_gpio_idx i;
47 struct gpio_desc *desc_array[UART_GPIO_MAX];
48 int value_array[UART_GPIO_MAX];
49 unsigned int count = 0;
51 for (i = 0; i < UART_GPIO_MAX; i++)
52 if (!IS_ERR_OR_NULL(gpios->gpio[i]) &&
53 mctrl_gpios_desc[i].dir_out) {
54 desc_array[count] = gpios->gpio[i];
55 value_array[count] = !!(mctrl & mctrl_gpios_desc[i].mctrl);
58 gpiod_set_array_value(count, desc_array, value_array);
60 EXPORT_SYMBOL_GPL(mctrl_gpio_set);
62 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
63 enum mctrl_gpio_idx gidx)
65 return gpios->gpio[gidx];
67 EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod);
69 unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
71 enum mctrl_gpio_idx i;
73 for (i = 0; i < UART_GPIO_MAX; i++) {
74 if (gpios->gpio[i] && !mctrl_gpios_desc[i].dir_out) {
75 if (gpiod_get_value(gpios->gpio[i]))
76 *mctrl |= mctrl_gpios_desc[i].mctrl;
78 *mctrl &= ~mctrl_gpios_desc[i].mctrl;
84 EXPORT_SYMBOL_GPL(mctrl_gpio_get);
86 struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx)
88 struct mctrl_gpios *gpios;
89 enum mctrl_gpio_idx i;
91 gpios = devm_kzalloc(dev, sizeof(*gpios), GFP_KERNEL);
93 return ERR_PTR(-ENOMEM);
95 for (i = 0; i < UART_GPIO_MAX; i++) {
96 enum gpiod_flags flags;
98 if (mctrl_gpios_desc[i].dir_out)
99 flags = GPIOD_OUT_LOW;
104 devm_gpiod_get_index_optional(dev,
105 mctrl_gpios_desc[i].name,
108 if (IS_ERR(gpios->gpio[i]))
109 return ERR_CAST(gpios->gpio[i]);
114 EXPORT_SYMBOL_GPL(mctrl_gpio_init);
116 void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
118 enum mctrl_gpio_idx i;
120 for (i = 0; i < UART_GPIO_MAX; i++)
121 if (!IS_ERR_OR_NULL(gpios->gpio[i]))
122 devm_gpiod_put(dev, gpios->gpio[i]);
123 devm_kfree(dev, gpios);
125 EXPORT_SYMBOL_GPL(mctrl_gpio_free);