staging: gdm7240: adding LTE USB driver

GCT Semiconductor GDM7240 is 4G LTE chip.
This driver supports GCT reference platform as a USB device.

Signed-off-by: Won Kang <wonkang@gctsemi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 367 insertions, 0 deletions

diff --git a/drivers/staging/gdm724x/gdm_tty.c b/drivers/staging/gdm724x/gdm_tty.c
new file mode 100644
index 000000000000..4d4040e3b101
--- /dev/null
+++ b/drivers/staging/gdm724x/gdm_tty.c
@@ -0,0 +1,367 @@
+/*
+ * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
+ *
+ * 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/version.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/usb/cdc.h>
+#include <linux/serial.h>
+#include "gdm_tty.h"
+
+#define GDM_TTY_MAJOR 0
+#define GDM_TTY_MINOR 32
+
+#define ACM_CTRL_DTR 0x01
+#define ACM_CTRL_RTS 0x02
+#define ACM_CTRL_DSR 0x02
+#define ACM_CTRL_RI  0x08
+#define ACM_CTRL_DCD 0x01
+
+#define WRITE_SIZE 2048
+
+#define MUX_TX_MAX_SIZE 2048
+
+#define gdm_tty_send(n, d, l, i, c, b) (\
+	n->tty_dev->send_func(n->tty_dev->priv_dev, d, l, i, c, b))
+#define gdm_tty_recv(n, c) (\
+	n->tty_dev->recv_func(n->tty_dev->priv_dev, c))
+#define gdm_tty_send_control(n, r, v, d, l) (\
+	n->tty_dev->send_control(n->tty_dev->priv_dev, r, v, d, l))
+
+#define acm_set_comm_feature(n, v)	\
+	gdm_tty_send_control(n, 0x02, v, NULL, 0)
+
+#define GDM_TTY_READY(tty_str) (tty_str && tty_str->tty_dev && tty_str->port.count)
+
+struct tty_driver *g_tty_drv[TTY_MAX_COUNT] = {NULL, };
+struct tty_str *g_tty_str[TTY_MAX_COUNT][GDM_TTY_MINOR] = {{NULL, }, };
+
+static char *DRIVER_STRING[TTY_MAX_COUNT] = {"GCTATC", "GCTDM"};
+static char *DEVICE_STRING[TTY_MAX_COUNT] = {"GCT-ATC", "GCT-DM"};
+
+static DEFINE_MUTEX(open_mutex);
+
+static struct tty_port_operations gdm_tty_port_ops = {
+};
+
+static int gdm_tty_open(struct tty_struct *tty, struct file *filp)
+{
+	struct tty_str *tty_str = NULL;
+	int i;
+	int ret = 0;
+
+	mutex_lock(&open_mutex);
+
+	for (i = 0; i < TTY_MAX_COUNT; i++) {
+		if (!strcmp(tty->driver->driver_name, DRIVER_STRING[i])) {
+			tty_str = g_tty_str[i][tty->index];
+			break;
+		}
+	}
+
+	if (!tty_str) {
+		printk(KERN_INFO "glte: no tty device\n");
+		mutex_unlock(&open_mutex);
+		return -ENODEV;
+	}
+
+	set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
+
+	tty->driver_data = tty_str;
+	tty_port_tty_set(&tty_str->port, tty);
+	tty_str->port.count++;
+	set_bit(ASYNCB_INITIALIZED, &tty_str->port.flags);
+	ret = tty_port_block_til_ready(&tty_str->port, tty, filp);
+
+	mutex_unlock(&open_mutex);
+
+	return ret;
+}
+
+static void gdm_tty_close(struct tty_struct *tty, struct file *filp)
+{
+	struct tty_str *tty_str = tty->driver_data;
+	int i;
+
+	if (!tty_str) {
+		printk(KERN_INFO "glte: tty device already close\n");
+		return;
+	}
+
+	if (tty_str->port.count != 0) {
+		tty_port_close_start(&tty_str->port, tty, filp);
+		tty_port_close_end(&tty_str->port, tty);
+
+		if (tty_str->port.count == 0)
+			tty_port_tty_set(&tty_str->port, NULL);
+			tty_str->port.tty = NULL;
+	}
+
+	if (!tty_str->tty_dev) {
+		for (i = 0; i < TTY_MAX_COUNT; i++) {
+			if (!strcmp(tty->driver->driver_name, DRIVER_STRING[i]))
+				break;
+		}
+
+		if (i < TTY_MAX_COUNT) {
+			tty_unregister_device(g_tty_drv[i], tty->index);
+			tty_port_tty_set(&tty_str->port, NULL);
+			kfree(tty_str);
+			g_tty_str[i][tty->index] = NULL;
+		}
+	}
+}
+
+static int gdm_tty_recv_complete(void *data, int len, int index, int minor, int complete)
+{
+	struct tty_str *tty_str = g_tty_str[index][minor];
+	struct tty_struct *tty;
+
+	if (!GDM_TTY_READY(tty_str)) {
+		if (complete == RECV_PACKET_PROCESS_COMPLETE)
+			gdm_tty_recv(tty_str, gdm_tty_recv_complete);
+		return TO_HOST_PORT_CLOSE;
+	}
+
+	if (!data || !len)
+		goto complete_routine;
+
+	tty = tty_port_tty_get(&tty_str->port);
+
+	if (tty_buffer_request_room(tty, len) == len) {
+		tty_insert_flip_string(tty, data, len);
+		tty_flip_buffer_push(tty);
+	} else {
+		tty_kref_put(tty);
+		return TO_HOST_BUFFER_REQUEST_FAIL;
+	}
+
+	tty_kref_put(tty);
+complete_routine:
+	if (complete == RECV_PACKET_PROCESS_COMPLETE)
+		gdm_tty_recv(tty_str, gdm_tty_recv_complete);
+
+	return TO_HOST_SUCCESS;
+}
+
+static void gdm_tty_send_complete(void *arg)
+{
+	struct tty_str *tty_str = (struct tty_str *)arg;
+	struct tty_struct *tty;
+
+	if (!GDM_TTY_READY(tty_str))
+		return;
+
+	tty = tty_port_tty_get(&tty_str->port);
+	tty_wakeup(tty);
+	tty_kref_put(tty);
+}
+
+static int gdm_tty_write(struct tty_struct *tty, const unsigned char *buf, int len)
+{
+	struct tty_str *tty_str = tty->driver_data;
+	int remain = len;
+	int sent_len = 0;
+	int sending_len = 0;
+
+	if (!GDM_TTY_READY(tty_str))
+		return -ENODEV;
+
+	if (!len)
+		return 0;
+
+	while (1) {
+		sending_len = remain > MUX_TX_MAX_SIZE ? MUX_TX_MAX_SIZE : remain;
+		gdm_tty_send(tty_str,
+			     (void *)(buf+sent_len),
+			     sending_len,
+			     tty_str->tty_drv_index,
+			     gdm_tty_send_complete,
+			     tty_str
+			    );
+		sent_len += sending_len;
+		remain -= sending_len;
+		if (remain <= 0)
+			break;
+	}
+
+	return len;
+}
+
+static int gdm_tty_write_room(struct tty_struct *tty)
+{
+	struct tty_str *tty_str = tty->driver_data;
+
+	if (!GDM_TTY_READY(tty_str))
+		return -ENODEV;
+
+	return WRITE_SIZE;
+}
+
+static int gdm_tty_tiocmget(struct tty_struct *tty)
+{
+	struct tty_str *tty_str = tty->driver_data;
+
+	if (!GDM_TTY_READY(tty_str))
+		return -ENODEV;
+
+	return (0 & ACM_CTRL_DTR ? TIOCM_DTR : 0) |
+	       (0 & ACM_CTRL_RTS ? TIOCM_RTS : 0) |
+	       (0 & ACM_CTRL_DSR ? TIOCM_DSR : 0) |
+	       (0 & ACM_CTRL_RI  ? TIOCM_RI  : 0) |
+	       (0 & ACM_CTRL_DCD ? TIOCM_CD  : 0) |
+	       TIOCM_CTS;
+}
+
+static int gdm_tty_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
+{
+	struct tty_str *tty_str = tty->driver_data;
+
+	if (!GDM_TTY_READY(tty_str))
+		return -ENODEV;
+
+	return 1;
+}
+
+int register_lte_tty_device(struct tty_dev *tty_dev, struct device *dev)
+{
+	struct tty_str *tty_str;
+	int i, j;
+
+	for (i = 0; i < TTY_MAX_COUNT; i++) {
+		for (j = 0; j < GDM_TTY_MINOR; j++) {
+			if (!g_tty_str[i][j])
+				break;
+		}
+
+		if (j == GDM_TTY_MINOR) {
+			tty_dev->minor[i] = j;
+			return -1;
+		}
+
+		tty_str = kmalloc(sizeof(struct tty_str), GFP_KERNEL);
+		if (!tty_str)
+			return -ENOMEM;
+
+		g_tty_str[i][j] = tty_str;
+
+		tty_str->tty_dev = tty_dev;
+		tty_str->tty_drv_index = i;
+		tty_dev->minor[i] = j;
+		tty_port_init(&tty_str->port);
+		tty_str->port.ops = &gdm_tty_port_ops;
+
+		if (strcmp(DEVICE_STRING[i], "GCT-ATC") != 0)
+			dev = NULL;
+		tty_register_device(g_tty_drv[i], j, dev);
+	}
+
+	acm_set_comm_feature(tty_str, 1);
+
+	for (i = 0; i < MAX_ISSUE_NUM; i++)
+		gdm_tty_recv(tty_str, gdm_tty_recv_complete);
+
+	return 0;
+}
+
+void unregister_lte_tty_device(struct tty_dev *tty_dev)
+{
+	struct tty_str *tty_str;
+	int i;
+
+	for (i = 0; i < TTY_MAX_COUNT; i++) {
+		if (tty_dev->minor[i] >= GDM_TTY_MINOR)
+			continue;
+
+		tty_str = g_tty_str[i][tty_dev->minor[i]];
+		if (!tty_str)
+			continue;
+
+		tty_str->tty_dev = NULL;
+
+		if (!tty_str->port.count) {
+			tty_unregister_device(g_tty_drv[i], tty_dev->minor[i]);
+			tty_port_tty_set(&tty_str->port, NULL);
+			kfree(tty_str);
+			g_tty_str[i][tty_dev->minor[i]] = NULL;
+		}
+	}
+}
+
+static void gdm_tty_set_termios(struct tty_struct *tty, struct ktermios *termios_old)
+{
+	return;
+}
+
+static const struct tty_operations gdm_tty_ops = {
+	.open = gdm_tty_open,
+	.close = gdm_tty_close,
+	.write = gdm_tty_write,
+	.write_room = gdm_tty_write_room,
+	.tiocmget = gdm_tty_tiocmget,
+	.tiocmset = gdm_tty_tiocmset,
+	.set_termios = gdm_tty_set_termios,
+};
+
+int register_lte_tty_driver(void)
+{
+	struct tty_driver *tty_driver = NULL;
+	int i;
+	int ret;
+
+	for (i = 0; i < TTY_MAX_COUNT; i++) {
+		tty_driver = alloc_tty_driver(GDM_TTY_MINOR);
+		if (!tty_driver) {
+			printk(KERN_ERR "glte: alloc_tty_driver fail\n");
+			return -ENOMEM;
+		}
+
+		tty_driver->owner = THIS_MODULE;
+		tty_driver->driver_name = DRIVER_STRING[i];
+		tty_driver->name = DEVICE_STRING[i];
+		tty_driver->major = GDM_TTY_MAJOR;
+		tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
+		tty_driver->subtype = SERIAL_TYPE_NORMAL;
+		tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
+		tty_driver->init_termios = tty_std_termios;
+		tty_driver->init_termios.c_cflag = B9600 | CS8 | HUPCL | CLOCAL;
+		tty_driver->init_termios.c_lflag = ISIG | ICANON | IEXTEN;
+		tty_set_operations(tty_driver, &gdm_tty_ops);
+
+		ret = tty_register_driver(tty_driver);
+
+		g_tty_drv[i] = tty_driver;
+	}
+
+	return ret;
+}
+
+void unregister_lte_tty_driver(void)
+{
+	struct tty_driver *tty_driver;
+	int i;
+
+	for (i = 0; i < TTY_MAX_COUNT; i++) {
+		tty_driver = g_tty_drv[i];
+		if (tty_driver) {
+			tty_unregister_driver(tty_driver);
+			put_tty_driver(tty_driver);
+		}
+	}
+}