msm_smd_tty driver provides tty device interface
to 'DS' and 'GPSNMEA' streaming SMD ports.
Cc: Brian Swetland <[email protected]>
Signed-off-by: Niranjana Vishwanathapura <[email protected]>
---
drivers/tty/serial/Kconfig | 9 ++
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/msm_smd_tty.c | 236 ++++++++++++++++++++++++++++++++++++++
3 files changed, 246 insertions(+), 0 deletions(-)
create mode 100644 drivers/tty/serial/msm_smd_tty.c
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index b1682d7..33cbc89 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1595,4 +1595,13 @@ config SERIAL_PCH_UART
This driver is for PCH(Platform controller Hub) UART of Intel EG20T
which is an IOH(Input/Output Hub) for x86 embedded processor.
Enabling PCH_DMA, this PCH UART works as DMA mode.
+
+config SERIAL_MSM_SMD
+ bool "Enable tty device interface for some SMD ports"
+ default n
+ depends on MSM_SMD
+ help
+ Enables userspace clients to read and write to some streaming SMD
+ ports via tty device interface for MSM chipset.
+
endmenu
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index 8ea92e9..0c6aefb 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -92,3 +92,4 @@ obj-$(CONFIG_SERIAL_MRST_MAX3110) += mrst_max3110.o
obj-$(CONFIG_SERIAL_MFD_HSU) += mfd.o
obj-$(CONFIG_SERIAL_IFX6X60) += ifx6x60.o
obj-$(CONFIG_SERIAL_PCH_UART) += pch_uart.o
+obj-$(CONFIG_SERIAL_MSM_SMD) += msm_smd_tty.o
diff --git a/drivers/tty/serial/msm_smd_tty.c b/drivers/tty/serial/msm_smd_tty.c
new file mode 100644
index 0000000..beeff1e
--- /dev/null
+++ b/drivers/tty/serial/msm_smd_tty.c
@@ -0,0 +1,236 @@
+/* drivers/tty/serial/msm_smd_tty.c
+ *
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
+ * Author: Brian Swetland <[email protected]>
+ *
+ * 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(tty, &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(tty);
+ }
+
+ /* 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)
+{
+ int i, res = 0;
+ int n = tty->index;
+ const char *name = NULL;
+ struct smd_tty_info *info = smd_tty + n;
+
+ for (i = 0; i < smd_tty_channels_len; i++) {
+ if (smd_tty_channels[i].id == n) {
+ 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;
+ struct tty_struct *tty = tty_port_tty_get(tport);
+
+ info = tty->driver_data;
+ if (info->ch) {
+ smd_close(info->ch);
+ info->ch = 0;
+ }
+
+ tty->driver_data = 0;
+ tty_kref_put(tty);
+}
+
+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->owner = THIS_MODULE;
+ 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++) {
+ tty_port_init(&smd_tty[smd_tty_channels[i].id].port);
+ smd_tty[smd_tty_channels[i].id].port.ops = &smd_tty_port_ops;
+ tty_register_device(smd_tty_driver, smd_tty_channels[i].id, 0);
+ }
+
+ return 0;
+}
+
+module_init(smd_tty_init);
--
1.5.6.3
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
On Wed, 9 Feb 2011 11:16:34 -0800
Niranjana Vishwanathapura <[email protected]> wrote:
> msm_smd_tty driver provides tty device interface
> to 'DS' and 'GPSNMEA' streaming SMD ports.
>
> Cc: Brian Swetland <[email protected]>
> Signed-off-by: Niranjana Vishwanathapura <[email protected]>
Acked-by: Alan Cox <[email protected]>
Thanks for reworking it for the current refcount/port stuff
Alan