[mirror_ubuntu-jammy-kernel.git] / drivers / tty / goldfish.c

/*
 * 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>
#include <linux/mm.h>
#include <linux/dma-mapping.h>

/* Goldfish tty register's offsets */
#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

/* Goldfish tty commands */
#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,
		     unsigned int count,
		     int 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);
	writel(count, base + GOLDFISH_TTY_REG_DATA_LEN);

	if (is_write)
		writel(GOLDFISH_TTY_CMD_WRITE_BUFFER,
		       base + GOLDFISH_TTY_REG_CMD);
	else
		writel(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,
			    unsigned int count,
			    int 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) {
		/*
		 * Goldfish TTY for Ranchu platform uses
		 * physical addresses and DMA for read/write operations
		 */
		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;

			/*
			 * Map the buffer's virtual address to the DMA address
			 * so the buffer can be accessed by the device.
			 */
			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);

			/*
			 * Unmap the previously mapped region after
			 * the completion of the read/write operation.
			 */
			dma_unmap_single(qtty->dev, dma_handle, avail, dma_dir);

			addr += avail;
		}
	} else {
		/*
		 * Old style Goldfish TTY used on the Goldfish platform
		 * uses virtual addresses.
		 */
		do_rw_io(qtty, addr, count, is_write);
	}
}

static void goldfish_tty_do_write(int line, const char *buf,
				  unsigned int count)
{
	struct goldfish_tty *qtty = &goldfish_ttys[line];
	unsigned long address = (unsigned long)(void *)buf;

	goldfish_tty_rw(qtty, address, count, 1);
}

static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id)
{
	struct goldfish_tty *qtty = dev_id;
	void __iomem *base = qtty->base;
	unsigned long address;
	unsigned char *buf;
	u32 count;

	count = readl(base + GOLDFISH_TTY_REG_BYTES_READY);
	if (count == 0)
		return IRQ_NONE;

	count = tty_prepare_flip_string(&qtty->port, &buf, count);

	address = (unsigned long)(void *)buf;
	goldfish_tty_rw(qtty, address, count, 0);

	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_REG_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_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 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_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(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 = -ENODEV;
	struct resource *r;
	struct device *ttydev;
	void __iomem *base;
	u32 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;
	}

	r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (!r) {
		pr_err("goldfish_tty: No IRQ resource available!\n");
		goto err_unmap;
	}

	irq = r->start;

	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;

	/*
	 * Goldfish TTY device used by the Goldfish emulator
	 * should identify itself with 0, forcing the driver
	 * to use virtual addresses. Goldfish TTY device
	 * on Ranchu emulator (qemu2) returns 1 here and
	 * driver will use physical addresses.
	 */
	qtty->version = readl(base + GOLDFISH_TTY_REG_VERSION);

	/*
	 * Goldfish TTY device on Ranchu emulator (qemu2)
	 * will use DMA for read/write IO operations.
	 */
	if (qtty->version > 0) {
		/*
		 * Initialize dma_mask to 32-bits.
		 */
		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;
		}
	}

	writel(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:
	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 int 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, 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 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_LICENSE("GPL v2");
Commit	Line	Data
666b7793 AH	1	/*
	2	* Copyright (C) 2007 Google, Inc.
	3	* Copyright (C) 2012 Intel, Inc.
	4	*
	5	* This software is licensed under the terms of the GNU General Public
	6	* License version 2, as published by the Free Software Foundation, and
	7	* may be copied, distributed, and modified under those terms.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	*/
	15
	16	#include <linux/console.h>
666b7793 AH	17	#include <linux/interrupt.h>
	18	#include <linux/platform_device.h>
	19	#include <linux/tty.h>
	20	#include <linux/tty_flip.h>
	21	#include <linux/slab.h>
	22	#include <linux/io.h>
	23	#include <linux/module.h>
e0f682e0	24	#include <linux/goldfish.h>
7157d2be MD	25	#include <linux/mm.h>
7157d2be MD	26	#include <linux/dma-mapping.h>
666b7793	27
2296eee7 AM	28	/* Goldfish tty register's offsets */
	29	#define GOLDFISH_TTY_REG_BYTES_READY 0x04
	30	#define GOLDFISH_TTY_REG_CMD 0x08
	31	#define GOLDFISH_TTY_REG_DATA_PTR 0x10
	32	#define GOLDFISH_TTY_REG_DATA_LEN 0x14
	33	#define GOLDFISH_TTY_REG_DATA_PTR_HIGH 0x18
7157d2be	34	#define GOLDFISH_TTY_REG_VERSION 0x20
2296eee7 AM	35
	36	/* Goldfish tty commands */
	37	#define GOLDFISH_TTY_CMD_INT_DISABLE 0
	38	#define GOLDFISH_TTY_CMD_INT_ENABLE 1
	39	#define GOLDFISH_TTY_CMD_WRITE_BUFFER 2
	40	#define GOLDFISH_TTY_CMD_READ_BUFFER 3
666b7793 AH	41
	42	struct goldfish_tty {
	43	struct tty_port port;
	44	spinlock_t lock;
	45	void __iomem *base;
	46	u32 irq;
	47	int opencount;
	48	struct console console;
7157d2be MD	49	u32 version;
7157d2be MD	50	struct device *dev;
666b7793 AH	51	};
	52
	53	static DEFINE_MUTEX(goldfish_tty_lock);
	54	static struct tty_driver *goldfish_tty_driver;
	55	static u32 goldfish_tty_line_count = 8;
	56	static u32 goldfish_tty_current_line_count;
	57	static struct goldfish_tty *goldfish_ttys;
	58
7157d2be MD	59	static void do_rw_io(struct goldfish_tty *qtty,
	60	unsigned long address,
	61	unsigned int count,
	62	int is_write)
666b7793 AH	63	{
666b7793 AH	64	unsigned long irq_flags;
666b7793	65	void __iomem *base = qtty->base;
7157d2be	66
666b7793	67	spin_lock_irqsave(&qtty->lock, irq_flags);
7157d2be	68	gf_write_ptr((void *)address, base + GOLDFISH_TTY_REG_DATA_PTR,
2296eee7 AM	69	base + GOLDFISH_TTY_REG_DATA_PTR_HIGH);
2296eee7 AM	70	writel(count, base + GOLDFISH_TTY_REG_DATA_LEN);
7157d2be MD	71
	72	if (is_write)
	73	writel(GOLDFISH_TTY_CMD_WRITE_BUFFER,
	74	base + GOLDFISH_TTY_REG_CMD);
	75	else
	76	writel(GOLDFISH_TTY_CMD_READ_BUFFER,
	77	base + GOLDFISH_TTY_REG_CMD);
	78
666b7793 AH	79	spin_unlock_irqrestore(&qtty->lock, irq_flags);
	80	}
	81
7157d2be MD	82	static void goldfish_tty_rw(struct goldfish_tty *qtty,
	83	unsigned long addr,
	84	unsigned int count,
	85	int is_write)
	86	{
	87	dma_addr_t dma_handle;
	88	enum dma_data_direction dma_dir;
	89
	90	dma_dir = (is_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
	91	if (qtty->version > 0) {
	92	/*
	93	* Goldfish TTY for Ranchu platform uses
	94	* physical addresses and DMA for read/write operations
	95	*/
	96	unsigned long addr_end = addr + count;
	97
	98	while (addr < addr_end) {
	99	unsigned long pg_end = (addr & PAGE_MASK) + PAGE_SIZE;
	100	unsigned long next =
	101	pg_end < addr_end ? pg_end : addr_end;
	102	unsigned long avail = next - addr;
	103
	104	/*
	105	* Map the buffer's virtual address to the DMA address
	106	* so the buffer can be accessed by the device.
	107	*/
	108	dma_handle = dma_map_single(qtty->dev, (void *)addr,
	109	avail, dma_dir);
	110
	111	if (dma_mapping_error(qtty->dev, dma_handle)) {
	112	dev_err(qtty->dev, "tty: DMA mapping error.\n");
	113	return;
	114	}
	115	do_rw_io(qtty, dma_handle, avail, is_write);
	116
	117	/*
	118	* Unmap the previously mapped region after
	119	* the completion of the read/write operation.
	120	*/
	121	dma_unmap_single(qtty->dev, dma_handle, avail, dma_dir);
	122
	123	addr += avail;
	124	}
	125	} else {
	126	/*
	127	* Old style Goldfish TTY used on the Goldfish platform
	128	* uses virtual addresses.
	129	*/
	130	do_rw_io(qtty, addr, count, is_write);
	131	}
	132	}
	133
	134	static void goldfish_tty_do_write(int line, const char *buf,
	135	unsigned int count)
	136	{
	137	struct goldfish_tty *qtty = &goldfish_ttys[line];
	138	unsigned long address = (unsigned long)(void *)buf;
	139
	140	goldfish_tty_rw(qtty, address, count, 1);
	141	}
	142
666b7793 AH	143	static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id)
666b7793 AH	144	{
465893e1	145	struct goldfish_tty *qtty = dev_id;
666b7793	146	void __iomem *base = qtty->base;
7157d2be	147	unsigned long address;
666b7793 AH	148	unsigned char *buf;
666b7793 AH	149	u32 count;
666b7793	150
2296eee7	151	count = readl(base + GOLDFISH_TTY_REG_BYTES_READY);
d78055dc	152	if (count == 0)
666b7793 AH	153	return IRQ_NONE;
666b7793 AH	154
ebcf0981	155	count = tty_prepare_flip_string(&qtty->port, &buf, count);
7157d2be MD	156
	157	address = (unsigned long)(void *)buf;
	158	goldfish_tty_rw(qtty, address, count, 0);
	159
ebcf0981	160	tty_schedule_flip(&qtty->port);
666b7793 AH	161	return IRQ_HANDLED;
	162	}
	163
	164	static int goldfish_tty_activate(struct tty_port port, struct tty_struct tty)
	165	{
d78055dc A	166	struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
d78055dc A	167	port);
2296eee7	168	writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
666b7793 AH	169	return 0;
	170	}
	171
	172	static void goldfish_tty_shutdown(struct tty_port *port)
	173	{
d78055dc A	174	struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
d78055dc A	175	port);
2296eee7	176	writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
666b7793 AH	177	}
666b7793 AH	178
d78055dc	179	static int goldfish_tty_open(struct tty_struct tty, struct file filp)
666b7793 AH	180	{
	181	struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
	182	return tty_port_open(&qtty->port, tty, filp);
	183	}
	184
d78055dc	185	static void goldfish_tty_close(struct tty_struct tty, struct file filp)
666b7793 AH	186	{
	187	tty_port_close(tty->port, tty, filp);
	188	}
	189
	190	static void goldfish_tty_hangup(struct tty_struct *tty)
	191	{
	192	tty_port_hangup(tty->port);
	193	}
	194
d78055dc A	195	static int goldfish_tty_write(struct tty_struct tty, const unsigned char buf,
d78055dc A	196	int count)
666b7793 AH	197	{
	198	goldfish_tty_do_write(tty->index, buf, count);
	199	return count;
	200	}
	201
	202	static int goldfish_tty_write_room(struct tty_struct *tty)
	203	{
	204	return 0x10000;
	205	}
	206
	207	static int goldfish_tty_chars_in_buffer(struct tty_struct *tty)
	208	{
	209	struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
	210	void __iomem *base = qtty->base;
2296eee7	211	return readl(base + GOLDFISH_TTY_REG_BYTES_READY);
666b7793 AH	212	}
666b7793 AH	213
d78055dc A	214	static void goldfish_tty_console_write(struct console co, const char b,
d78055dc A	215	unsigned count)
666b7793 AH	216	{
	217	goldfish_tty_do_write(co->index, b, count);
	218	}
	219
d78055dc A	220	static struct tty_driver goldfish_tty_console_device(struct console c,
d78055dc A	221	int *index)
666b7793 AH	222	{
	223	*index = c->index;
	224	return goldfish_tty_driver;
	225	}
	226
	227	static int goldfish_tty_console_setup(struct console co, char options)
	228	{
fda2b418	229	if ((unsigned)co->index >= goldfish_tty_line_count)
666b7793	230	return -ENODEV;
a4dc9236	231	if (!goldfish_ttys[co->index].base)
666b7793 AH	232	return -ENODEV;
	233	return 0;
	234	}
	235
04b757df	236	static const struct tty_port_operations goldfish_port_ops = {
666b7793 AH	237	.activate = goldfish_tty_activate,
	238	.shutdown = goldfish_tty_shutdown
	239	};
	240
d78055dc	241	static const struct tty_operations goldfish_tty_ops = {
666b7793 AH	242	.open = goldfish_tty_open,
	243	.close = goldfish_tty_close,
	244	.hangup = goldfish_tty_hangup,
	245	.write = goldfish_tty_write,
	246	.write_room = goldfish_tty_write_room,
	247	.chars_in_buffer = goldfish_tty_chars_in_buffer,
	248	};
	249
	250	static int goldfish_tty_create_driver(void)
	251	{
	252	int ret;
	253	struct tty_driver *tty;
	254
d78055dc A	255	goldfish_ttys = kzalloc(sizeof(goldfish_ttys)
	256	goldfish_tty_line_count, GFP_KERNEL);
	257	if (goldfish_ttys == NULL) {
666b7793 AH	258	ret = -ENOMEM;
	259	goto err_alloc_goldfish_ttys_failed;
	260	}
	261	tty = alloc_tty_driver(goldfish_tty_line_count);
d78055dc	262	if (tty == NULL) {
666b7793 AH	263	ret = -ENOMEM;
	264	goto err_alloc_tty_driver_failed;
	265	}
	266	tty->driver_name = "goldfish";
	267	tty->name = "ttyGF";
	268	tty->type = TTY_DRIVER_TYPE_SERIAL;
	269	tty->subtype = SERIAL_TYPE_NORMAL;
	270	tty->init_termios = tty_std_termios;
d78055dc A	271	tty->flags = TTY_DRIVER_RESET_TERMIOS \| TTY_DRIVER_REAL_RAW \|
d78055dc A	272	TTY_DRIVER_DYNAMIC_DEV;
666b7793 AH	273	tty_set_operations(tty, &goldfish_tty_ops);
666b7793 AH	274	ret = tty_register_driver(tty);
d78055dc	275	if (ret)
666b7793 AH	276	goto err_tty_register_driver_failed;
	277
	278	goldfish_tty_driver = tty;
	279	return 0;
	280
	281	err_tty_register_driver_failed:
	282	put_tty_driver(tty);
	283	err_alloc_tty_driver_failed:
	284	kfree(goldfish_ttys);
	285	goldfish_ttys = NULL;
	286	err_alloc_goldfish_ttys_failed:
	287	return ret;
	288	}
	289
	290	static void goldfish_tty_delete_driver(void)
	291	{
	292	tty_unregister_driver(goldfish_tty_driver);
	293	put_tty_driver(goldfish_tty_driver);
	294	goldfish_tty_driver = NULL;
	295	kfree(goldfish_ttys);
	296	goldfish_ttys = NULL;
	297	}
	298
	299	static int goldfish_tty_probe(struct platform_device *pdev)
	300	{
	301	struct goldfish_tty *qtty;
7157d2be	302	int ret = -ENODEV;
666b7793 AH	303	struct resource *r;
	304	struct device *ttydev;
	305	void __iomem *base;
	306	u32 irq;
465893e1	307	unsigned int line;
666b7793 AH	308
666b7793 AH	309	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
7157d2be MD	310	if (!r) {
	311	pr_err("goldfish_tty: No MEM resource available!\n");
	312	return -ENOMEM;
	313	}
666b7793 AH	314
666b7793 AH	315	base = ioremap(r->start, 0x1000);
7157d2be MD	316	if (!base) {
	317	pr_err("goldfish_tty: Unable to ioremap base!\n");
	318	return -ENOMEM;
	319	}
666b7793 AH	320
666b7793 AH	321	r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
7157d2be MD	322	if (!r) {
7157d2be MD	323	pr_err("goldfish_tty: No IRQ resource available!\n");
666b7793	324	goto err_unmap;
7157d2be	325	}
666b7793 AH	326
	327	irq = r->start;
	328
666b7793	329	mutex_lock(&goldfish_tty_lock);
465893e1 GH	330
	331	if (pdev->id == PLATFORM_DEVID_NONE)
	332	line = goldfish_tty_current_line_count;
	333	else
	334	line = pdev->id;
	335
7157d2be MD	336	if (line >= goldfish_tty_line_count) {
	337	pr_err("goldfish_tty: Reached maximum tty number of %d.\n",
	338	goldfish_tty_current_line_count);
	339	ret = -ENOMEM;
	340	goto err_unlock;
	341	}
465893e1	342
d78055dc	343	if (goldfish_tty_current_line_count == 0) {
666b7793	344	ret = goldfish_tty_create_driver();
d78055dc	345	if (ret)
7157d2be	346	goto err_unlock;
666b7793 AH	347	}
	348	goldfish_tty_current_line_count++;
	349
465893e1	350	qtty = &goldfish_ttys[line];
666b7793 AH	351	spin_lock_init(&qtty->lock);
	352	tty_port_init(&qtty->port);
	353	qtty->port.ops = &goldfish_port_ops;
	354	qtty->base = base;
	355	qtty->irq = irq;
7157d2be MD	356	qtty->dev = &pdev->dev;
	357
	358	/*
	359	* Goldfish TTY device used by the Goldfish emulator
	360	* should identify itself with 0, forcing the driver
	361	* to use virtual addresses. Goldfish TTY device
	362	* on Ranchu emulator (qemu2) returns 1 here and
	363	* driver will use physical addresses.
	364	*/
	365	qtty->version = readl(base + GOLDFISH_TTY_REG_VERSION);
	366
	367	/*
	368	* Goldfish TTY device on Ranchu emulator (qemu2)
	369	* will use DMA for read/write IO operations.
	370	*/
	371	if (qtty->version > 0) {
	372	/*
	373	* Initialize dma_mask to 32-bits.
	374	*/
	375	if (!pdev->dev.dma_mask)
	376	pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
	377	ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
	378	if (ret) {
	379	dev_err(&pdev->dev, "No suitable DMA available.\n");
	380	goto err_dec_line_count;
	381	}
	382	}
666b7793	383
2296eee7	384	writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_REG_CMD);
666b7793	385
d78055dc	386	ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED,
7157d2be MD	387	"goldfish_tty", qtty);
	388	if (ret) {
	389	pr_err("goldfish_tty: No IRQ available!\n");
	390	goto err_dec_line_count;
	391	}
666b7793 AH	392
666b7793 AH	393	ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver,
7157d2be	394	line, &pdev->dev);
d78055dc	395	if (IS_ERR(ttydev)) {
666b7793 AH	396	ret = PTR_ERR(ttydev);
	397	goto err_tty_register_device_failed;
	398	}
	399
	400	strcpy(qtty->console.name, "ttyGF");
	401	qtty->console.write = goldfish_tty_console_write;
	402	qtty->console.device = goldfish_tty_console_device;
	403	qtty->console.setup = goldfish_tty_console_setup;
	404	qtty->console.flags = CON_PRINTBUFFER;
465893e1	405	qtty->console.index = line;
666b7793	406	register_console(&qtty->console);
465893e1	407	platform_set_drvdata(pdev, qtty);
666b7793 AH	408
	409	mutex_unlock(&goldfish_tty_lock);
	410	return 0;
	411
666b7793	412	err_tty_register_device_failed:
1a5c2d1d	413	free_irq(irq, qtty);
7157d2be	414	err_dec_line_count:
666b7793	415	goldfish_tty_current_line_count--;
d78055dc	416	if (goldfish_tty_current_line_count == 0)
666b7793	417	goldfish_tty_delete_driver();
7157d2be	418	err_unlock:
666b7793 AH	419	mutex_unlock(&goldfish_tty_lock);
	420	err_unmap:
	421	iounmap(base);
	422	return ret;
	423	}
	424
	425	static int goldfish_tty_remove(struct platform_device *pdev)
	426	{
465893e1	427	struct goldfish_tty *qtty = platform_get_drvdata(pdev);
666b7793 AH	428
	429	mutex_lock(&goldfish_tty_lock);
	430
666b7793	431	unregister_console(&qtty->console);
465893e1	432	tty_unregister_device(goldfish_tty_driver, qtty->console.index);
666b7793	433	iounmap(qtty->base);
a4dc9236	434	qtty->base = NULL;
666b7793 AH	435	free_irq(qtty->irq, pdev);
666b7793 AH	436	goldfish_tty_current_line_count--;
d78055dc	437	if (goldfish_tty_current_line_count == 0)
666b7793 AH	438	goldfish_tty_delete_driver();
	439	mutex_unlock(&goldfish_tty_lock);
	440	return 0;
	441	}
	442
9b883eea MD	443	static const struct of_device_id goldfish_tty_of_match[] = {
	444	{ .compatible = "google,goldfish-tty", },
	445	{},
	446	};
	447
	448	MODULE_DEVICE_TABLE(of, goldfish_tty_of_match);
	449
666b7793 AH	450	static struct platform_driver goldfish_tty_platform_driver = {
	451	.probe = goldfish_tty_probe,
	452	.remove = goldfish_tty_remove,
	453	.driver = {
9b883eea MD	454	.name = "goldfish_tty",
9b883eea MD	455	.of_match_table = goldfish_tty_of_match,
666b7793 AH	456	}
	457	};
	458
	459	module_platform_driver(goldfish_tty_platform_driver);
	460
	461	MODULE_LICENSE("GPL v2");