Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / tty / serial / serial_mctrl_gpio.c

diff --git a/kernel/drivers/tty/serial/serial_mctrl_gpio.c b/kernel/drivers/tty/serial/serial_mctrl_gpio.c
new file mode 100644 (file)
index 0000000..0ec756c
--- /dev/null
+++ b/kernel/drivers/tty/serial/serial_mctrl_gpio.c
@@ -0,0 +1,125 @@
+/*
+ * Helpers for controlling modem lines via GPIO
+ *
+ * Copyright (C) 2014 Paratronic S.A.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/termios.h>
+
+#include "serial_mctrl_gpio.h"
+
+struct mctrl_gpios {
+       struct gpio_desc *gpio[UART_GPIO_MAX];
+};
+
+static const struct {
+       const char *name;
+       unsigned int mctrl;
+       bool dir_out;
+} mctrl_gpios_desc[UART_GPIO_MAX] = {
+       { "cts", TIOCM_CTS, false, },
+       { "dsr", TIOCM_DSR, false, },
+       { "dcd", TIOCM_CD, false, },
+       { "rng", TIOCM_RNG, false, },
+       { "rts", TIOCM_RTS, true, },
+       { "dtr", TIOCM_DTR, true, },
+       { "out1", TIOCM_OUT1, true, },
+       { "out2", TIOCM_OUT2, true, },
+};
+
+void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
+{
+       enum mctrl_gpio_idx i;
+       struct gpio_desc *desc_array[UART_GPIO_MAX];
+       int value_array[UART_GPIO_MAX];
+       unsigned int count = 0;
+
+       for (i = 0; i < UART_GPIO_MAX; i++)
+               if (!IS_ERR_OR_NULL(gpios->gpio[i]) &&
+                   mctrl_gpios_desc[i].dir_out) {
+                       desc_array[count] = gpios->gpio[i];
+                       value_array[count] = !!(mctrl & mctrl_gpios_desc[i].mctrl);
+                       count++;
+               }
+       gpiod_set_array(count, desc_array, value_array);
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_set);
+
+struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
+                                     enum mctrl_gpio_idx gidx)
+{
+       return gpios->gpio[gidx];
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod);
+
+unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
+{
+       enum mctrl_gpio_idx i;
+
+       for (i = 0; i < UART_GPIO_MAX; i++) {
+               if (gpios->gpio[i] && !mctrl_gpios_desc[i].dir_out) {
+                       if (gpiod_get_value(gpios->gpio[i]))
+                               *mctrl |= mctrl_gpios_desc[i].mctrl;
+                       else
+                               *mctrl &= ~mctrl_gpios_desc[i].mctrl;
+               }
+       }
+
+       return *mctrl;
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_get);
+
+struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx)
+{
+       struct mctrl_gpios *gpios;
+       enum mctrl_gpio_idx i;
+
+       gpios = devm_kzalloc(dev, sizeof(*gpios), GFP_KERNEL);
+       if (!gpios)
+               return ERR_PTR(-ENOMEM);
+
+       for (i = 0; i < UART_GPIO_MAX; i++) {
+               enum gpiod_flags flags;
+
+               if (mctrl_gpios_desc[i].dir_out)
+                       flags = GPIOD_OUT_LOW;
+               else
+                       flags = GPIOD_IN;
+
+               gpios->gpio[i] =
+                       devm_gpiod_get_index_optional(dev,
+                                                     mctrl_gpios_desc[i].name,
+                                                     idx, flags);
+
+               if (IS_ERR(gpios->gpio[i]))
+                       return ERR_CAST(gpios->gpio[i]);
+       }
+
+       return gpios;
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_init);
+
+void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
+{
+       enum mctrl_gpio_idx i;
+
+       for (i = 0; i < UART_GPIO_MAX; i++)
+               if (!IS_ERR_OR_NULL(gpios->gpio[i]))
+                       devm_gpiod_put(dev, gpios->gpio[i]);
+       devm_kfree(dev, gpios);
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_free);