--- /dev/null
+/*
+ * 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/init.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;
+ struct tty_struct *tty;
+
+ count = readl(base + GOLDFISH_TTY_BYTES_READY);
+ if(count == 0)
+ return IRQ_NONE;
+
+ tty = tty_port_tty_get(&qtty->port);
+ if (tty) {
+ count = tty_prepare_flip_string(tty, &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(tty);
+ tty_kref_put(tty);
+ }
+ 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");
projects / karo-tx-linux.git / commitdiff