--- /dev/null
+/*
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
+ * Author: Brian Swetland <swetland@google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/module.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/wait.h>
+
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+
+#include <mach/msm_smd.h>
+
+#define MAX_SMD_TTYS 32
+
+struct smd_tty_info {
+ struct tty_port port;
+ smd_channel_t *ch;
+};
+
+struct smd_tty_channel_desc {
+ int id;
+ const char *name;
+};
+
+static struct smd_tty_info smd_tty[MAX_SMD_TTYS];
+
+static const struct smd_tty_channel_desc smd_default_tty_channels[] = {
+ { .id = 0, .name = "SMD_DS" },
+ { .id = 27, .name = "SMD_GPSNMEA" },
+};
+
+static const struct smd_tty_channel_desc *smd_tty_channels =
+ smd_default_tty_channels;
+static int smd_tty_channels_len = ARRAY_SIZE(smd_default_tty_channels);
+
+static void smd_tty_notify(void *priv, unsigned event)
+{
+ unsigned char *ptr;
+ int avail;
+ struct smd_tty_info *info = priv;
+ struct tty_struct *tty;
+
+ if (event != SMD_EVENT_DATA)
+ return;
+
+ tty = tty_port_tty_get(&info->port);
+ if (!tty)
+ return;
+
+ for (;;) {
+ if (test_bit(TTY_THROTTLED, &tty->flags))
+ break;
+ avail = smd_read_avail(info->ch);
+ if (avail == 0)
+ break;
+
+ avail = tty_prepare_flip_string(&info->port, &ptr, avail);
+
+ if (smd_read(info->ch, ptr, avail) != avail) {
+ /* shouldn't be possible since we're in interrupt
+ ** context here and nobody else could 'steal' our
+ ** characters.
+ */
+ pr_err("OOPS - smd_tty_buffer mismatch?!");
+ }
+
+ tty_flip_buffer_push(&info->port);
+ }
+
+ /* XXX only when writable and necessary */
+ tty_wakeup(tty);
+ tty_kref_put(tty);
+}
+
+static int smd_tty_port_activate(struct tty_port *tport, struct tty_struct *tty)
+{
+ struct smd_tty_info *info = container_of(tport, struct smd_tty_info,
+ port);
+ int i, res = 0;
+ const char *name = NULL;
+
+ for (i = 0; i < smd_tty_channels_len; i++) {
+ if (smd_tty_channels[i].id == tty->index) {
+ name = smd_tty_channels[i].name;
+ break;
+ }
+ }
+ if (!name)
+ return -ENODEV;
+
+ if (info->ch)
+ smd_kick(info->ch);
+ else
+ res = smd_open(name, &info->ch, info, smd_tty_notify);
+
+ if (!res)
+ tty->driver_data = info;
+
+ return res;
+}
+
+static void smd_tty_port_shutdown(struct tty_port *tport)
+{
+ struct smd_tty_info *info = container_of(tport, struct smd_tty_info,
+ port);
+
+ if (info->ch) {
+ smd_close(info->ch);
+ info->ch = 0;
+ }
+}
+
+static int smd_tty_open(struct tty_struct *tty, struct file *f)
+{
+ struct smd_tty_info *info = smd_tty + tty->index;
+
+ return tty_port_open(&info->port, tty, f);
+}
+
+static void smd_tty_close(struct tty_struct *tty, struct file *f)
+{
+ struct smd_tty_info *info = tty->driver_data;
+
+ tty_port_close(&info->port, tty, f);
+}
+
+static int smd_tty_write(struct tty_struct *tty,
+ const unsigned char *buf, int len)
+{
+ struct smd_tty_info *info = tty->driver_data;
+ int avail;
+
+ /* if we're writing to a packet channel we will
+ ** never be able to write more data than there
+ ** is currently space for
+ */
+ avail = smd_write_avail(info->ch);
+ if (len > avail)
+ len = avail;
+
+ return smd_write(info->ch, buf, len);
+}
+
+static int smd_tty_write_room(struct tty_struct *tty)
+{
+ struct smd_tty_info *info = tty->driver_data;
+ return smd_write_avail(info->ch);
+}
+
+static int smd_tty_chars_in_buffer(struct tty_struct *tty)
+{
+ struct smd_tty_info *info = tty->driver_data;
+ return smd_read_avail(info->ch);
+}
+
+static void smd_tty_unthrottle(struct tty_struct *tty)
+{
+ struct smd_tty_info *info = tty->driver_data;
+ smd_kick(info->ch);
+}
+
+static const struct tty_port_operations smd_tty_port_ops = {
+ .shutdown = smd_tty_port_shutdown,
+ .activate = smd_tty_port_activate,
+};
+
+static const struct tty_operations smd_tty_ops = {
+ .open = smd_tty_open,
+ .close = smd_tty_close,
+ .write = smd_tty_write,
+ .write_room = smd_tty_write_room,
+ .chars_in_buffer = smd_tty_chars_in_buffer,
+ .unthrottle = smd_tty_unthrottle,
+};
+
+static struct tty_driver *smd_tty_driver;
+
+static int __init smd_tty_init(void)
+{
+ int ret, i;
+
+ smd_tty_driver = alloc_tty_driver(MAX_SMD_TTYS);
+ if (smd_tty_driver == 0)
+ return -ENOMEM;
+
+ smd_tty_driver->driver_name = "smd_tty_driver";
+ smd_tty_driver->name = "smd";
+ smd_tty_driver->major = 0;
+ smd_tty_driver->minor_start = 0;
+ smd_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
+ smd_tty_driver->subtype = SERIAL_TYPE_NORMAL;
+ smd_tty_driver->init_termios = tty_std_termios;
+ smd_tty_driver->init_termios.c_iflag = 0;
+ smd_tty_driver->init_termios.c_oflag = 0;
+ smd_tty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+ smd_tty_driver->init_termios.c_lflag = 0;
+ smd_tty_driver->flags = TTY_DRIVER_RESET_TERMIOS |
+ TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
+ tty_set_operations(smd_tty_driver, &smd_tty_ops);
+
+ ret = tty_register_driver(smd_tty_driver);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < smd_tty_channels_len; i++) {
+ struct tty_port *port = &smd_tty[smd_tty_channels[i].id].port;
+ tty_port_init(port);
+ port->ops = &smd_tty_port_ops;
+ tty_port_register_device(port, smd_tty_driver,
+ smd_tty_channels[i].id, NULL);
+ }
+
+ return 0;
+}
+
+module_init(smd_tty_init);
Code Review / kvmfornfv.git / blobdiff