/*
* Copyright (C) 2007 Google, Inc.
* Copyright (C) 2012 Intel, Inc.
*
* 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/console.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/module.h>
enum {
GOLDFISH_TTY_PUT_CHAR = 0x00,
GOLDFISH_TTY_BYTES_READY = 0x04,
GOLDFISH_TTY_CMD = 0x08,
GOLDFISH_TTY_DATA_PTR = 0x10,
GOLDFISH_TTY_DATA_LEN = 0x14,
GOLDFISH_TTY_CMD_INT_DISABLE = 0,
GOLDFISH_TTY_CMD_INT_ENABLE = 1,
GOLDFISH_TTY_CMD_WRITE_BUFFER = 2,
GOLDFISH_TTY_CMD_READ_BUFFER = 3,
};
struct goldfish_tty {
struct tty_port port;
spinlock_t lock;
void __iomem *base;
u32 irq;
int opencount;
struct console console;
};
static DEFINE_MUTEX(goldfish_tty_lock);
static struct tty_driver *goldfish_tty_driver;
static u32 goldfish_tty_line_count = 8;
static u32 goldfish_tty_current_line_count;
static struct goldfish_tty *goldfish_ttys;
static void goldfish_tty_do_write(int line, const char *buf, unsigned count)
{
unsigned long irq_flags;
struct goldfish_tty *qtty = &goldfish_ttys[line];
void __iomem *base = qtty->base;
spin_lock_irqsave(&qtty->lock, irq_flags);
writel((u32)buf, base + GOLDFISH_TTY_DATA_PTR);
writel(count, base + GOLDFISH_TTY_DATA_LEN);
writel(GOLDFISH_TTY_CMD_WRITE_BUFFER, base + GOLDFISH_TTY_CMD);
spin_unlock_irqrestore(&qtty->lock, irq_flags);
}
static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id)
{
struct platform_device *pdev = dev_id;
struct goldfish_tty *qtty = &goldfish_ttys[pdev->id];
void __iomem *base = qtty->base;
unsigned long irq_flags;
unsigned char *buf;
u32 count;
count = readl(base + GOLDFISH_TTY_BYTES_READY);
if(count == 0)
return IRQ_NONE;
count = tty_prepare_flip_string(&qtty->port, &buf, count);
spin_lock_irqsave(&qtty->lock, irq_flags);
writel((u32)buf, base + GOLDFISH_TTY_DATA_PTR);
writel(count, base + GOLDFISH_TTY_DATA_LEN);
writel(GOLDFISH_TTY_CMD_READ_BUFFER, base + GOLDFISH_TTY_CMD);
spin_unlock_irqrestore(&qtty->lock, irq_flags);
tty_schedule_flip(&qtty->port);
return IRQ_HANDLED;
}
static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty)
{
struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, port);
writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_CMD);
return 0;
}
static void goldfish_tty_shutdown(struct tty_port *port)
{
struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, port);
writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_CMD);
}
static int goldfish_tty_open(struct tty_struct * tty, struct file * filp)
{
struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
return tty_port_open(&qtty->port, tty, filp);
}
static void goldfish_tty_close(struct tty_struct * tty, struct file * filp)
{
tty_port_close(tty->port, tty, filp);
}
static void goldfish_tty_hangup(struct tty_struct *tty)
{
tty_port_hangup(tty->port);
}
static int goldfish_tty_write(struct tty_struct * tty, const unsigned char *buf, int count)
{
goldfish_tty_do_write(tty->index, buf, count);
return count;
}
static int goldfish_tty_write_room(struct tty_struct *tty)
{
return 0x10000;
}
static int goldfish_tty_chars_in_buffer(struct tty_struct *tty)
{
struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
void __iomem *base = qtty->base;
return readl(base + GOLDFISH_TTY_BYTES_READY);
}
static void goldfish_tty_console_write(struct console *co, const char *b, unsigned count)
{
goldfish_tty_do_write(co->index, b, count);
}
static struct tty_driver *goldfish_tty_console_device(struct console *c, int *index)
{
*index = c->index;
return goldfish_tty_driver;
}
static int goldfish_tty_console_setup(struct console *co, char *options)
{
if((unsigned)co->index > goldfish_tty_line_count)
return -ENODEV;
if(goldfish_ttys[co->index].base == 0)
return -ENODEV;
return 0;
}
static struct tty_port_operations goldfish_port_ops = {
.activate = goldfish_tty_activate,
.shutdown = goldfish_tty_shutdown
};
static struct tty_operations goldfish_tty_ops = {
.open = goldfish_tty_open,
.close = goldfish_tty_close,
.hangup = goldfish_tty_hangup,
.write = goldfish_tty_write,
.write_room = goldfish_tty_write_room,
.chars_in_buffer = goldfish_tty_chars_in_buffer,
};
static int goldfish_tty_create_driver(void)
{
int ret;
struct tty_driver *tty;
goldfish_ttys = kzalloc(sizeof(*goldfish_ttys) * goldfish_tty_line_count, GFP_KERNEL);
if(goldfish_ttys == NULL) {
ret = -ENOMEM;
goto err_alloc_goldfish_ttys_failed;
}
tty = alloc_tty_driver(goldfish_tty_line_count);
if(tty == NULL) {
ret = -ENOMEM;
goto err_alloc_tty_driver_failed;
}
tty->driver_name = "goldfish";
tty->name = "ttyGF";
tty->type = TTY_DRIVER_TYPE_SERIAL;
tty->subtype = SERIAL_TYPE_NORMAL;
tty->init_termios = tty_std_termios;
tty->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
tty_set_operations(tty, &goldfish_tty_ops);
ret = tty_register_driver(tty);
if(ret)
goto err_tty_register_driver_failed;
goldfish_tty_driver = tty;
return 0;
err_tty_register_driver_failed:
put_tty_driver(tty);
err_alloc_tty_driver_failed:
kfree(goldfish_ttys);
goldfish_ttys = NULL;
err_alloc_goldfish_ttys_failed:
return ret;
}
static void goldfish_tty_delete_driver(void)
{
tty_unregister_driver(goldfish_tty_driver);
put_tty_driver(goldfish_tty_driver);
goldfish_tty_driver = NULL;
kfree(goldfish_ttys);
goldfish_ttys = NULL;
}
static int goldfish_tty_probe(struct platform_device *pdev)
{
struct goldfish_tty *qtty;
int ret = -EINVAL;
int i;
struct resource *r;
struct device *ttydev;
void __iomem *base;
u32 irq;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if(r == NULL)
return -EINVAL;
base = ioremap(r->start, 0x1000);
if (base == NULL)
pr_err("goldfish_tty: unable to remap base\n");
r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if(r == NULL)
goto err_unmap;
irq = r->start;
if(pdev->id >= goldfish_tty_line_count)
goto err_unmap;
mutex_lock(&goldfish_tty_lock);
if(goldfish_tty_current_line_count == 0) {
ret = goldfish_tty_create_driver();
if(ret)
goto err_create_driver_failed;
}
goldfish_tty_current_line_count++;
qtty = &goldfish_ttys[pdev->id];
spin_lock_init(&qtty->lock);
tty_port_init(&qtty->port);
qtty->port.ops = &goldfish_port_ops;
qtty->base = base;
qtty->irq = irq;
writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_CMD);
ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED, "goldfish_tty", pdev);
if(ret)
goto err_request_irq_failed;
ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver,
pdev->id, &pdev->dev);
if(IS_ERR(ttydev)) {
ret = PTR_ERR(ttydev);
goto err_tty_register_device_failed;
}
strcpy(qtty->console.name, "ttyGF");
qtty->console.write = goldfish_tty_console_write;
qtty->console.device = goldfish_tty_console_device;
qtty->console.setup = goldfish_tty_console_setup;
qtty->console.flags = CON_PRINTBUFFER;
qtty->console.index = pdev->id;
register_console(&qtty->console);
mutex_unlock(&goldfish_tty_lock);
return 0;
tty_unregister_device(goldfish_tty_driver, i);
err_tty_register_device_failed:
free_irq(irq, pdev);
err_request_irq_failed:
goldfish_tty_current_line_count--;
if(goldfish_tty_current_line_count == 0)
goldfish_tty_delete_driver();
err_create_driver_failed:
mutex_unlock(&goldfish_tty_lock);
err_unmap:
iounmap(base);
return ret;
}
static int goldfish_tty_remove(struct platform_device *pdev)
{
struct goldfish_tty *qtty;
mutex_lock(&goldfish_tty_lock);
qtty = &goldfish_ttys[pdev->id];
unregister_console(&qtty->console);
tty_unregister_device(goldfish_tty_driver, pdev->id);
iounmap(qtty->base);
qtty->base = 0;
free_irq(qtty->irq, pdev);
goldfish_tty_current_line_count--;
if(goldfish_tty_current_line_count == 0)
goldfish_tty_delete_driver();
mutex_unlock(&goldfish_tty_lock);
return 0;
}
static struct platform_driver goldfish_tty_platform_driver = {
.probe = goldfish_tty_probe,
.remove = goldfish_tty_remove,
.driver = {
.name = "goldfish_tty"
}
};
module_platform_driver(goldfish_tty_platform_driver);
MODULE_LICENSE("GPL v2");
