diff options
Diffstat (limited to 'kernel/drivers/tty/goldfish.c')
| -rw-r--r-- | kernel/drivers/tty/goldfish.c | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/kernel/drivers/tty/goldfish.c b/kernel/drivers/tty/goldfish.c new file mode 100644 index 000000000..0655fecf8 --- /dev/null +++ b/kernel/drivers/tty/goldfish.c @@ -0,0 +1,337 @@ +/* + * 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> +#include <linux/goldfish.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_DATA_PTR_HIGH = 0x18, + + 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); + gf_write64((u64)buf, base + GOLDFISH_TTY_DATA_PTR, + base + GOLDFISH_TTY_DATA_PTR_HIGH); + 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); + gf_write64((u64)buf, base + GOLDFISH_TTY_DATA_PTR, + base + GOLDFISH_TTY_DATA_PTR_HIGH); + 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) + return -ENODEV; + return 0; +} + +static 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(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; + 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; + +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 = NULL; + 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"); |