#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>
#include <linux/mod_devicetable.h>
#include <linux/goldfish.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include <linux/serial_core.h>
#define GOLDFISH_TTY_REG_BYTES_READY 0x04
#define GOLDFISH_TTY_REG_CMD 0x08
#define GOLDFISH_TTY_REG_DATA_PTR 0x10
#define GOLDFISH_TTY_REG_DATA_LEN 0x14
#define GOLDFISH_TTY_REG_DATA_PTR_HIGH 0x18
#define GOLDFISH_TTY_REG_VERSION 0x20
#define GOLDFISH_TTY_CMD_INT_DISABLE 0
#define GOLDFISH_TTY_CMD_INT_ENABLE 1
#define GOLDFISH_TTY_CMD_WRITE_BUFFER 2
#define 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;
u32 version;
struct device *dev;
};
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 do_rw_io(struct goldfish_tty *qtty, unsigned long address,
size_t count, bool is_write)
{
unsigned long irq_flags;
void __iomem *base = qtty->base;
spin_lock_irqsave(&qtty->lock, irq_flags);
gf_write_ptr((void *)address, base + GOLDFISH_TTY_REG_DATA_PTR,
base + GOLDFISH_TTY_REG_DATA_PTR_HIGH);
gf_iowrite32(count, base + GOLDFISH_TTY_REG_DATA_LEN);
if (is_write)
gf_iowrite32(GOLDFISH_TTY_CMD_WRITE_BUFFER,
base + GOLDFISH_TTY_REG_CMD);
else
gf_iowrite32(GOLDFISH_TTY_CMD_READ_BUFFER,
base + GOLDFISH_TTY_REG_CMD);
spin_unlock_irqrestore(&qtty->lock, irq_flags);
}
static void goldfish_tty_rw(struct goldfish_tty *qtty, unsigned long addr,
size_t count, bool is_write)
{
dma_addr_t dma_handle;
enum dma_data_direction dma_dir;
dma_dir = (is_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
if (qtty->version > 0) {
unsigned long addr_end = addr + count;
while (addr < addr_end) {
unsigned long pg_end = (addr & PAGE_MASK) + PAGE_SIZE;
unsigned long next =
pg_end < addr_end ? pg_end : addr_end;
unsigned long avail = next - addr;
dma_handle = dma_map_single(qtty->dev, (void *)addr,
avail, dma_dir);
if (dma_mapping_error(qtty->dev, dma_handle)) {
dev_err(qtty->dev, "tty: DMA mapping error.\n");
return;
}
do_rw_io(qtty, dma_handle, avail, is_write);
dma_unmap_single(qtty->dev, dma_handle, avail, dma_dir);
addr += avail;
}
} else {
do_rw_io(qtty, addr, count, is_write);
}
}
static void goldfish_tty_do_write(int line, const u8 *buf, size_t count)
{
struct goldfish_tty *qtty = &goldfish_ttys[line];
goldfish_tty_rw(qtty, (unsigned long)buf, count, true);
}
static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id)
{
struct goldfish_tty *qtty = dev_id;
void __iomem *base = qtty->base;
u8 *buf;
u32 count;
count = gf_ioread32(base + GOLDFISH_TTY_REG_BYTES_READY);
if (count == 0)
return IRQ_NONE;
count = tty_prepare_flip_string(&qtty->port, &buf, count);
goldfish_tty_rw(qtty, (unsigned long)buf, count, false);
tty_flip_buffer_push(&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);
gf_iowrite32(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
return 0;
}
static void goldfish_tty_shutdown(struct tty_port *port)
{
struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
port);
gf_iowrite32(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_REG_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 ssize_t goldfish_tty_write(struct tty_struct *tty, const u8 *buf,
size_t count)
{
goldfish_tty_do_write(tty->index, buf, count);
return count;
}
static unsigned int goldfish_tty_write_room(struct tty_struct *tty)
{
return 0x10000;
}
static unsigned int goldfish_tty_chars_in_buffer(struct tty_struct *tty)
{
struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
void __iomem *base = qtty->base;
return gf_ioread32(base + GOLDFISH_TTY_REG_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)
return -ENODEV;
return 0;
}
static const struct tty_port_operations goldfish_port_ops = {
.activate = goldfish_tty_activate,
.shutdown = goldfish_tty_shutdown
};
static const 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_objs(*goldfish_ttys, goldfish_tty_line_count);
if (goldfish_ttys == NULL) {
ret = -ENOMEM;
goto err_alloc_goldfish_ttys_failed;
}
tty = tty_alloc_driver(goldfish_tty_line_count,
TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
TTY_DRIVER_DYNAMIC_DEV);
if (IS_ERR(tty)) {
ret = PTR_ERR(tty);
goto err_tty_alloc_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_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:
tty_driver_kref_put(tty);
err_tty_alloc_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);
tty_driver_kref_put(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 = -ENODEV;
struct resource *r;
struct device *ttydev;
void __iomem *base;
int irq;
unsigned int line;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r) {
pr_err("goldfish_tty: No MEM resource available!\n");
return -ENOMEM;
}
base = ioremap(r->start, 0x1000);
if (!base) {
pr_err("goldfish_tty: Unable to ioremap base!\n");
return -ENOMEM;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
ret = irq;
goto err_unmap;
}
mutex_lock(&goldfish_tty_lock);
if (pdev->id == PLATFORM_DEVID_NONE)
line = goldfish_tty_current_line_count;
else
line = pdev->id;
if (line >= goldfish_tty_line_count) {
pr_err("goldfish_tty: Reached maximum tty number of %d.\n",
goldfish_tty_current_line_count);
ret = -ENOMEM;
goto err_unlock;
}
if (goldfish_tty_current_line_count == 0) {
ret = goldfish_tty_create_driver();
if (ret)
goto err_unlock;
}
goldfish_tty_current_line_count++;
qtty = &goldfish_ttys[line];
spin_lock_init(&qtty->lock);
tty_port_init(&qtty->port);
qtty->port.ops = &goldfish_port_ops;
qtty->base = base;
qtty->irq = irq;
qtty->dev = &pdev->dev;
qtty->version = gf_ioread32(base + GOLDFISH_TTY_REG_VERSION);
if (qtty->version > 0) {
if (!pdev->dev.dma_mask)
pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
if (ret) {
dev_err(&pdev->dev, "No suitable DMA available.\n");
goto err_dec_line_count;
}
}
gf_iowrite32(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_REG_CMD);
ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED,
"goldfish_tty", qtty);
if (ret) {
pr_err("goldfish_tty: No IRQ available!\n");
goto err_dec_line_count;
}
ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver,
line, &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 = line;
register_console(&qtty->console);
platform_set_drvdata(pdev, qtty);
mutex_unlock(&goldfish_tty_lock);
return 0;
err_tty_register_device_failed:
free_irq(irq, qtty);
err_dec_line_count:
tty_port_destroy(&qtty->port);
goldfish_tty_current_line_count--;
if (goldfish_tty_current_line_count == 0)
goldfish_tty_delete_driver();
err_unlock:
mutex_unlock(&goldfish_tty_lock);
err_unmap:
iounmap(base);
return ret;
}
static void goldfish_tty_remove(struct platform_device *pdev)
{
struct goldfish_tty *qtty = platform_get_drvdata(pdev);
mutex_lock(&goldfish_tty_lock);
unregister_console(&qtty->console);
tty_unregister_device(goldfish_tty_driver, qtty->console.index);
iounmap(qtty->base);
qtty->base = NULL;
free_irq(qtty->irq, qtty);
tty_port_destroy(&qtty->port);
goldfish_tty_current_line_count--;
if (goldfish_tty_current_line_count == 0)
goldfish_tty_delete_driver();
mutex_unlock(&goldfish_tty_lock);
}
#ifdef CONFIG_GOLDFISH_TTY_EARLY_CONSOLE
static void gf_early_console_putchar(struct uart_port *port, unsigned char ch)
{
gf_iowrite32(ch, port->membase);
}
static void gf_early_write(struct console *con, const char *s, unsigned int n)
{
struct earlycon_device *dev = con->data;
uart_console_write(&dev->port, s, n, gf_early_console_putchar);
}
static int __init gf_earlycon_setup(struct earlycon_device *device,
const char *opt)
{
if (!device->port.membase)
return -ENODEV;
device->con->write = gf_early_write;
return 0;
}
OF_EARLYCON_DECLARE(early_gf_tty, "google,goldfish-tty", gf_earlycon_setup);
#endif
static const struct of_device_id goldfish_tty_of_match[] = {
{ .compatible = "google,goldfish-tty", },
{},
};
MODULE_DEVICE_TABLE(of, goldfish_tty_of_match);
static struct platform_driver goldfish_tty_platform_driver = {
.probe = goldfish_tty_probe,
.remove = goldfish_tty_remove,
.driver = {
.name = "goldfish_tty",
.of_match_table = goldfish_tty_of_match,
}
};
module_platform_driver(goldfish_tty_platform_driver);
MODULE_DESCRIPTION("Goldfish TTY Driver");
MODULE_LICENSE("GPL v2");
