tty: Add msm_smd_tty driver (daaf6ff4) · Commits · 戴 / test

drivers/tty/serial/Kconfig

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Original line number	Diff line number	Diff line
		@@ -1600,4 +1600,13 @@ config SERIAL_PCH_UART
		Output Hub) which is for IVI(In-Vehicle Infotainment) use.
		ML7213 is companion chip for Intel Atom E6xx series.
		ML7213 is completely compatible for Intel EG20T PCH.

		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

drivers/tty/serial/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

drivers/tty/serial/msm_smd_tty.c

0 → 100644

+236 −0

Original line number	Diff line number	Diff line
		/* drivers/tty/serial/msm_smd_tty.c
		*
		* 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(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);

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