[linux.git] / drivers / tty / goldfish.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2007 Google, Inc.
 * Copyright (C) 2012 Intel, Inc.
 * Copyright (C) 2017 Imagination Technologies Ltd.
 */

#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>
#include <linux/serial_core.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 = kcalloc(goldfish_tty_line_count,
				sizeof(*goldfish_ttys),
				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;
}

#ifdef CONFIG_GOLDFISH_TTY_EARLY_CONSOLE
static void gf_early_console_putchar(struct uart_port *port, int ch)
{
	__raw_writel(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_LICENSE("GPL v2");
Commit	Line	Data
e3b3d0f5	1	// SPDX-License-Identifier: GPL-2.0
666b7793 AH	2	/*
	3	* Copyright (C) 2007 Google, Inc.
	4	* Copyright (C) 2012 Intel, Inc.
3840ed95	5	* Copyright (C) 2017 Imagination Technologies Ltd.
666b7793 AH	6	*/
	7
	8	#include <linux/console.h>
666b7793 AH	9	#include <linux/interrupt.h>
	10	#include <linux/platform_device.h>
	11	#include <linux/tty.h>
	12	#include <linux/tty_flip.h>
	13	#include <linux/slab.h>
	14	#include <linux/io.h>
	15	#include <linux/module.h>
e0f682e0	16	#include <linux/goldfish.h>
7157d2be MD	17	#include <linux/mm.h>
7157d2be MD	18	#include <linux/dma-mapping.h>
3840ed95	19	#include <linux/serial_core.h>
666b7793	20
2296eee7 AM	21	/* Goldfish tty register's offsets */
	22	#define GOLDFISH_TTY_REG_BYTES_READY 0x04
	23	#define GOLDFISH_TTY_REG_CMD 0x08
	24	#define GOLDFISH_TTY_REG_DATA_PTR 0x10
	25	#define GOLDFISH_TTY_REG_DATA_LEN 0x14
	26	#define GOLDFISH_TTY_REG_DATA_PTR_HIGH 0x18
7157d2be	27	#define GOLDFISH_TTY_REG_VERSION 0x20
2296eee7 AM	28
	29	/* Goldfish tty commands */
	30	#define GOLDFISH_TTY_CMD_INT_DISABLE 0
	31	#define GOLDFISH_TTY_CMD_INT_ENABLE 1
	32	#define GOLDFISH_TTY_CMD_WRITE_BUFFER 2
	33	#define GOLDFISH_TTY_CMD_READ_BUFFER 3
666b7793 AH	34
	35	struct goldfish_tty {
	36	struct tty_port port;
	37	spinlock_t lock;
	38	void __iomem *base;
	39	u32 irq;
	40	int opencount;
	41	struct console console;
7157d2be MD	42	u32 version;
7157d2be MD	43	struct device *dev;
666b7793 AH	44	};
	45
	46	static DEFINE_MUTEX(goldfish_tty_lock);
	47	static struct tty_driver *goldfish_tty_driver;
	48	static u32 goldfish_tty_line_count = 8;
	49	static u32 goldfish_tty_current_line_count;
	50	static struct goldfish_tty *goldfish_ttys;
	51
7157d2be MD	52	static void do_rw_io(struct goldfish_tty *qtty,
	53	unsigned long address,
	54	unsigned int count,
	55	int is_write)
666b7793 AH	56	{
666b7793 AH	57	unsigned long irq_flags;
666b7793	58	void __iomem *base = qtty->base;
7157d2be	59
666b7793	60	spin_lock_irqsave(&qtty->lock, irq_flags);
7157d2be	61	gf_write_ptr((void *)address, base + GOLDFISH_TTY_REG_DATA_PTR,
2296eee7 AM	62	base + GOLDFISH_TTY_REG_DATA_PTR_HIGH);
2296eee7 AM	63	writel(count, base + GOLDFISH_TTY_REG_DATA_LEN);
7157d2be MD	64
	65	if (is_write)
	66	writel(GOLDFISH_TTY_CMD_WRITE_BUFFER,
	67	base + GOLDFISH_TTY_REG_CMD);
	68	else
	69	writel(GOLDFISH_TTY_CMD_READ_BUFFER,
	70	base + GOLDFISH_TTY_REG_CMD);
	71
666b7793 AH	72	spin_unlock_irqrestore(&qtty->lock, irq_flags);
	73	}
	74
7157d2be MD	75	static void goldfish_tty_rw(struct goldfish_tty *qtty,
	76	unsigned long addr,
	77	unsigned int count,
	78	int is_write)
	79	{
	80	dma_addr_t dma_handle;
	81	enum dma_data_direction dma_dir;
	82
	83	dma_dir = (is_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
	84	if (qtty->version > 0) {
	85	/*
	86	* Goldfish TTY for Ranchu platform uses
	87	* physical addresses and DMA for read/write operations
	88	*/
	89	unsigned long addr_end = addr + count;
	90
	91	while (addr < addr_end) {
	92	unsigned long pg_end = (addr & PAGE_MASK) + PAGE_SIZE;
	93	unsigned long next =
	94	pg_end < addr_end ? pg_end : addr_end;
	95	unsigned long avail = next - addr;
	96
	97	/*
	98	* Map the buffer's virtual address to the DMA address
	99	* so the buffer can be accessed by the device.
	100	*/
	101	dma_handle = dma_map_single(qtty->dev, (void *)addr,
	102	avail, dma_dir);
	103
	104	if (dma_mapping_error(qtty->dev, dma_handle)) {
	105	dev_err(qtty->dev, "tty: DMA mapping error.\n");
	106	return;
	107	}
	108	do_rw_io(qtty, dma_handle, avail, is_write);
	109
	110	/*
	111	* Unmap the previously mapped region after
	112	* the completion of the read/write operation.
	113	*/
	114	dma_unmap_single(qtty->dev, dma_handle, avail, dma_dir);
	115
	116	addr += avail;
	117	}
	118	} else {
	119	/*
	120	* Old style Goldfish TTY used on the Goldfish platform
	121	* uses virtual addresses.
	122	*/
	123	do_rw_io(qtty, addr, count, is_write);
	124	}
	125	}
	126
	127	static void goldfish_tty_do_write(int line, const char *buf,
	128	unsigned int count)
	129	{
	130	struct goldfish_tty *qtty = &goldfish_ttys[line];
	131	unsigned long address = (unsigned long)(void *)buf;
	132
	133	goldfish_tty_rw(qtty, address, count, 1);
	134	}
	135
666b7793 AH	136	static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id)
666b7793 AH	137	{
465893e1	138	struct goldfish_tty *qtty = dev_id;
666b7793	139	void __iomem *base = qtty->base;
7157d2be	140	unsigned long address;
666b7793 AH	141	unsigned char *buf;
666b7793 AH	142	u32 count;
666b7793	143
2296eee7	144	count = readl(base + GOLDFISH_TTY_REG_BYTES_READY);
d78055dc	145	if (count == 0)
666b7793 AH	146	return IRQ_NONE;
666b7793 AH	147
ebcf0981	148	count = tty_prepare_flip_string(&qtty->port, &buf, count);
7157d2be MD	149
	150	address = (unsigned long)(void *)buf;
	151	goldfish_tty_rw(qtty, address, count, 0);
	152
ebcf0981	153	tty_schedule_flip(&qtty->port);
666b7793 AH	154	return IRQ_HANDLED;
	155	}
	156
	157	static int goldfish_tty_activate(struct tty_port port, struct tty_struct tty)
	158	{
d78055dc A	159	struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
d78055dc A	160	port);
2296eee7	161	writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
666b7793 AH	162	return 0;
	163	}
	164
	165	static void goldfish_tty_shutdown(struct tty_port *port)
	166	{
d78055dc A	167	struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
d78055dc A	168	port);
2296eee7	169	writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
666b7793 AH	170	}
666b7793 AH	171
d78055dc	172	static int goldfish_tty_open(struct tty_struct tty, struct file filp)
666b7793 AH	173	{
	174	struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
	175	return tty_port_open(&qtty->port, tty, filp);
	176	}
	177
d78055dc	178	static void goldfish_tty_close(struct tty_struct tty, struct file filp)
666b7793 AH	179	{
	180	tty_port_close(tty->port, tty, filp);
	181	}
	182
	183	static void goldfish_tty_hangup(struct tty_struct *tty)
	184	{
	185	tty_port_hangup(tty->port);
	186	}
	187
d78055dc A	188	static int goldfish_tty_write(struct tty_struct tty, const unsigned char buf,
d78055dc A	189	int count)
666b7793 AH	190	{
	191	goldfish_tty_do_write(tty->index, buf, count);
	192	return count;
	193	}
	194
	195	static int goldfish_tty_write_room(struct tty_struct *tty)
	196	{
	197	return 0x10000;
	198	}
	199
	200	static int goldfish_tty_chars_in_buffer(struct tty_struct *tty)
	201	{
	202	struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
	203	void __iomem *base = qtty->base;
2296eee7	204	return readl(base + GOLDFISH_TTY_REG_BYTES_READY);
666b7793 AH	205	}
666b7793 AH	206
d78055dc A	207	static void goldfish_tty_console_write(struct console co, const char b,
d78055dc A	208	unsigned count)
666b7793 AH	209	{
	210	goldfish_tty_do_write(co->index, b, count);
	211	}
	212
d78055dc A	213	static struct tty_driver goldfish_tty_console_device(struct console c,
d78055dc A	214	int *index)
666b7793 AH	215	{
	216	*index = c->index;
	217	return goldfish_tty_driver;
	218	}
	219
	220	static int goldfish_tty_console_setup(struct console co, char options)
	221	{
fda2b418	222	if ((unsigned)co->index >= goldfish_tty_line_count)
666b7793	223	return -ENODEV;
a4dc9236	224	if (!goldfish_ttys[co->index].base)
666b7793 AH	225	return -ENODEV;
	226	return 0;
	227	}
	228
04b757df	229	static const struct tty_port_operations goldfish_port_ops = {
666b7793 AH	230	.activate = goldfish_tty_activate,
	231	.shutdown = goldfish_tty_shutdown
	232	};
	233
d78055dc	234	static const struct tty_operations goldfish_tty_ops = {
666b7793 AH	235	.open = goldfish_tty_open,
	236	.close = goldfish_tty_close,
	237	.hangup = goldfish_tty_hangup,
	238	.write = goldfish_tty_write,
	239	.write_room = goldfish_tty_write_room,
	240	.chars_in_buffer = goldfish_tty_chars_in_buffer,
	241	};
	242
	243	static int goldfish_tty_create_driver(void)
	244	{
	245	int ret;
	246	struct tty_driver *tty;
	247
6396bb22 KC	248	goldfish_ttys = kcalloc(goldfish_tty_line_count,
	249	sizeof(*goldfish_ttys),
	250	GFP_KERNEL);
d78055dc	251	if (goldfish_ttys == NULL) {
666b7793 AH	252	ret = -ENOMEM;
	253	goto err_alloc_goldfish_ttys_failed;
	254	}
	255	tty = alloc_tty_driver(goldfish_tty_line_count);
d78055dc	256	if (tty == NULL) {
666b7793 AH	257	ret = -ENOMEM;
	258	goto err_alloc_tty_driver_failed;
	259	}
	260	tty->driver_name = "goldfish";
	261	tty->name = "ttyGF";
	262	tty->type = TTY_DRIVER_TYPE_SERIAL;
	263	tty->subtype = SERIAL_TYPE_NORMAL;
	264	tty->init_termios = tty_std_termios;
d78055dc A	265	tty->flags = TTY_DRIVER_RESET_TERMIOS \| TTY_DRIVER_REAL_RAW \|
d78055dc A	266	TTY_DRIVER_DYNAMIC_DEV;
666b7793 AH	267	tty_set_operations(tty, &goldfish_tty_ops);
666b7793 AH	268	ret = tty_register_driver(tty);
d78055dc	269	if (ret)
666b7793 AH	270	goto err_tty_register_driver_failed;
	271
	272	goldfish_tty_driver = tty;
	273	return 0;
	274
	275	err_tty_register_driver_failed:
	276	put_tty_driver(tty);
	277	err_alloc_tty_driver_failed:
	278	kfree(goldfish_ttys);
	279	goldfish_ttys = NULL;
	280	err_alloc_goldfish_ttys_failed:
	281	return ret;
	282	}
	283
	284	static void goldfish_tty_delete_driver(void)
	285	{
	286	tty_unregister_driver(goldfish_tty_driver);
	287	put_tty_driver(goldfish_tty_driver);
	288	goldfish_tty_driver = NULL;
	289	kfree(goldfish_ttys);
	290	goldfish_ttys = NULL;
	291	}
	292
	293	static int goldfish_tty_probe(struct platform_device *pdev)
	294	{
	295	struct goldfish_tty *qtty;
7157d2be	296	int ret = -ENODEV;
666b7793 AH	297	struct resource *r;
	298	struct device *ttydev;
	299	void __iomem *base;
	300	u32 irq;
465893e1	301	unsigned int line;
666b7793 AH	302
666b7793 AH	303	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
7157d2be MD	304	if (!r) {
	305	pr_err("goldfish_tty: No MEM resource available!\n");
	306	return -ENOMEM;
	307	}
666b7793 AH	308
666b7793 AH	309	base = ioremap(r->start, 0x1000);
7157d2be MD	310	if (!base) {
	311	pr_err("goldfish_tty: Unable to ioremap base!\n");
	312	return -ENOMEM;
	313	}
666b7793 AH	314
666b7793 AH	315	r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
7157d2be MD	316	if (!r) {
7157d2be MD	317	pr_err("goldfish_tty: No IRQ resource available!\n");
666b7793	318	goto err_unmap;
7157d2be	319	}
666b7793 AH	320
	321	irq = r->start;
	322
666b7793	323	mutex_lock(&goldfish_tty_lock);
465893e1 GH	324
	325	if (pdev->id == PLATFORM_DEVID_NONE)
	326	line = goldfish_tty_current_line_count;
	327	else
	328	line = pdev->id;
	329
7157d2be MD	330	if (line >= goldfish_tty_line_count) {
	331	pr_err("goldfish_tty: Reached maximum tty number of %d.\n",
	332	goldfish_tty_current_line_count);
	333	ret = -ENOMEM;
	334	goto err_unlock;
	335	}
465893e1	336
d78055dc	337	if (goldfish_tty_current_line_count == 0) {
666b7793	338	ret = goldfish_tty_create_driver();
d78055dc	339	if (ret)
7157d2be	340	goto err_unlock;
666b7793 AH	341	}
	342	goldfish_tty_current_line_count++;
	343
465893e1	344	qtty = &goldfish_ttys[line];
666b7793 AH	345	spin_lock_init(&qtty->lock);
	346	tty_port_init(&qtty->port);
	347	qtty->port.ops = &goldfish_port_ops;
	348	qtty->base = base;
	349	qtty->irq = irq;
7157d2be MD	350	qtty->dev = &pdev->dev;
	351
	352	/*
	353	* Goldfish TTY device used by the Goldfish emulator
	354	* should identify itself with 0, forcing the driver
	355	* to use virtual addresses. Goldfish TTY device
	356	* on Ranchu emulator (qemu2) returns 1 here and
	357	* driver will use physical addresses.
	358	*/
	359	qtty->version = readl(base + GOLDFISH_TTY_REG_VERSION);
	360
	361	/*
	362	* Goldfish TTY device on Ranchu emulator (qemu2)
	363	* will use DMA for read/write IO operations.
	364	*/
	365	if (qtty->version > 0) {
	366	/*
	367	* Initialize dma_mask to 32-bits.
	368	*/
	369	if (!pdev->dev.dma_mask)
	370	pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
	371	ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
	372	if (ret) {
	373	dev_err(&pdev->dev, "No suitable DMA available.\n");
	374	goto err_dec_line_count;
	375	}
	376	}
666b7793	377
2296eee7	378	writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_REG_CMD);
666b7793	379
d78055dc	380	ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED,
7157d2be MD	381	"goldfish_tty", qtty);
	382	if (ret) {
	383	pr_err("goldfish_tty: No IRQ available!\n");
	384	goto err_dec_line_count;
	385	}
666b7793 AH	386
666b7793 AH	387	ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver,
7157d2be	388	line, &pdev->dev);
d78055dc	389	if (IS_ERR(ttydev)) {
666b7793 AH	390	ret = PTR_ERR(ttydev);
	391	goto err_tty_register_device_failed;
	392	}
	393
	394	strcpy(qtty->console.name, "ttyGF");
	395	qtty->console.write = goldfish_tty_console_write;
	396	qtty->console.device = goldfish_tty_console_device;
	397	qtty->console.setup = goldfish_tty_console_setup;
	398	qtty->console.flags = CON_PRINTBUFFER;
465893e1	399	qtty->console.index = line;
666b7793	400	register_console(&qtty->console);
465893e1	401	platform_set_drvdata(pdev, qtty);
666b7793 AH	402
	403	mutex_unlock(&goldfish_tty_lock);
	404	return 0;
	405
666b7793	406	err_tty_register_device_failed:
1a5c2d1d	407	free_irq(irq, qtty);
7157d2be	408	err_dec_line_count:
666b7793	409	goldfish_tty_current_line_count--;
d78055dc	410	if (goldfish_tty_current_line_count == 0)
666b7793	411	goldfish_tty_delete_driver();
7157d2be	412	err_unlock:
666b7793 AH	413	mutex_unlock(&goldfish_tty_lock);
	414	err_unmap:
	415	iounmap(base);
	416	return ret;
	417	}
	418
	419	static int goldfish_tty_remove(struct platform_device *pdev)
	420	{
465893e1	421	struct goldfish_tty *qtty = platform_get_drvdata(pdev);
666b7793 AH	422
	423	mutex_lock(&goldfish_tty_lock);
	424
666b7793	425	unregister_console(&qtty->console);
465893e1	426	tty_unregister_device(goldfish_tty_driver, qtty->console.index);
666b7793	427	iounmap(qtty->base);
a4dc9236	428	qtty->base = NULL;
666b7793 AH	429	free_irq(qtty->irq, pdev);
666b7793 AH	430	goldfish_tty_current_line_count--;
d78055dc	431	if (goldfish_tty_current_line_count == 0)
666b7793 AH	432	goldfish_tty_delete_driver();
	433	mutex_unlock(&goldfish_tty_lock);
	434	return 0;
	435	}
	436
6a28fd2b	437	#ifdef CONFIG_GOLDFISH_TTY_EARLY_CONSOLE
3840ed95 MD	438	static void gf_early_console_putchar(struct uart_port *port, int ch)
	439	{
	440	__raw_writel(ch, port->membase);
	441	}
	442
	443	static void gf_early_write(struct console con, const char s, unsigned int n)
	444	{
	445	struct earlycon_device *dev = con->data;
	446
	447	uart_console_write(&dev->port, s, n, gf_early_console_putchar);
	448	}
	449
	450	static int __init gf_earlycon_setup(struct earlycon_device *device,
	451	const char *opt)
	452	{
	453	if (!device->port.membase)
	454	return -ENODEV;
	455
	456	device->con->write = gf_early_write;
	457	return 0;
	458	}
	459
	460	OF_EARLYCON_DECLARE(early_gf_tty, "google,goldfish-tty", gf_earlycon_setup);
6a28fd2b	461	#endif
3840ed95	462
9b883eea MD	463	static const struct of_device_id goldfish_tty_of_match[] = {
	464	{ .compatible = "google,goldfish-tty", },
	465	{},
	466	};
	467
	468	MODULE_DEVICE_TABLE(of, goldfish_tty_of_match);
	469
666b7793 AH	470	static struct platform_driver goldfish_tty_platform_driver = {
	471	.probe = goldfish_tty_probe,
	472	.remove = goldfish_tty_remove,
	473	.driver = {
9b883eea MD	474	.name = "goldfish_tty",
9b883eea MD	475	.of_match_table = goldfish_tty_of_match,
666b7793 AH	476	}
	477	};
	478
	479	module_platform_driver(goldfish_tty_platform_driver);
	480
	481	MODULE_LICENSE("GPL v2");