[mirror_ubuntu-artful-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>

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;

	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);
	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(&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 == 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");
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>
	24
	25	enum {
	26	GOLDFISH_TTY_PUT_CHAR = 0x00,
	27	GOLDFISH_TTY_BYTES_READY = 0x04,
	28	GOLDFISH_TTY_CMD = 0x08,
	29
	30	GOLDFISH_TTY_DATA_PTR = 0x10,
	31	GOLDFISH_TTY_DATA_LEN = 0x14,
	32
	33	GOLDFISH_TTY_CMD_INT_DISABLE = 0,
	34	GOLDFISH_TTY_CMD_INT_ENABLE = 1,
	35	GOLDFISH_TTY_CMD_WRITE_BUFFER = 2,
	36	GOLDFISH_TTY_CMD_READ_BUFFER = 3,
	37	};
	38
	39	struct goldfish_tty {
	40	struct tty_port port;
	41	spinlock_t lock;
	42	void __iomem *base;
	43	u32 irq;
	44	int opencount;
	45	struct console console;
	46	};
	47
	48	static DEFINE_MUTEX(goldfish_tty_lock);
	49	static struct tty_driver *goldfish_tty_driver;
	50	static u32 goldfish_tty_line_count = 8;
	51	static u32 goldfish_tty_current_line_count;
	52	static struct goldfish_tty *goldfish_ttys;
	53
	54	static void goldfish_tty_do_write(int line, const char *buf, unsigned count)
	55	{
	56	unsigned long irq_flags;
	57	struct goldfish_tty *qtty = &goldfish_ttys[line];
	58	void __iomem *base = qtty->base;
	59	spin_lock_irqsave(&qtty->lock, irq_flags);
	60	writel((u32)buf, base + GOLDFISH_TTY_DATA_PTR);
	61	writel(count, base + GOLDFISH_TTY_DATA_LEN);
	62	writel(GOLDFISH_TTY_CMD_WRITE_BUFFER, base + GOLDFISH_TTY_CMD);
	63	spin_unlock_irqrestore(&qtty->lock, irq_flags);
	64	}
	65
	66	static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id)
	67	{
	68	struct platform_device *pdev = dev_id;
	69	struct goldfish_tty *qtty = &goldfish_ttys[pdev->id];
	70	void __iomem *base = qtty->base;
	71	unsigned long irq_flags;
	72	unsigned char *buf;
	73	u32 count;
666b7793 AH	74
	75	count = readl(base + GOLDFISH_TTY_BYTES_READY);
	76	if(count == 0)
	77	return IRQ_NONE;
	78
ebcf0981 AC	79	count = tty_prepare_flip_string(&qtty->port, &buf, count);
	80	spin_lock_irqsave(&qtty->lock, irq_flags);
	81	writel((u32)buf, base + GOLDFISH_TTY_DATA_PTR);
	82	writel(count, base + GOLDFISH_TTY_DATA_LEN);
	83	writel(GOLDFISH_TTY_CMD_READ_BUFFER, base + GOLDFISH_TTY_CMD);
	84	spin_unlock_irqrestore(&qtty->lock, irq_flags);
	85	tty_schedule_flip(&qtty->port);
666b7793 AH	86	return IRQ_HANDLED;
	87	}
	88
	89	static int goldfish_tty_activate(struct tty_port port, struct tty_struct tty)
	90	{
	91	struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, port);
	92	writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_CMD);
	93	return 0;
	94	}
	95
	96	static void goldfish_tty_shutdown(struct tty_port *port)
	97	{
	98	struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, port);
	99	writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_CMD);
	100	}
	101
	102	static int goldfish_tty_open(struct tty_struct * tty, struct file * filp)
	103	{
	104	struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
	105	return tty_port_open(&qtty->port, tty, filp);
	106	}
	107
	108	static void goldfish_tty_close(struct tty_struct * tty, struct file * filp)
	109	{
	110	tty_port_close(tty->port, tty, filp);
	111	}
	112
	113	static void goldfish_tty_hangup(struct tty_struct *tty)
	114	{
	115	tty_port_hangup(tty->port);
	116	}
	117
	118	static int goldfish_tty_write(struct tty_struct * tty, const unsigned char *buf, int count)
	119	{
	120	goldfish_tty_do_write(tty->index, buf, count);
	121	return count;
	122	}
	123
	124	static int goldfish_tty_write_room(struct tty_struct *tty)
	125	{
	126	return 0x10000;
	127	}
	128
	129	static int goldfish_tty_chars_in_buffer(struct tty_struct *tty)
	130	{
	131	struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
	132	void __iomem *base = qtty->base;
	133	return readl(base + GOLDFISH_TTY_BYTES_READY);
	134	}
	135
	136	static void goldfish_tty_console_write(struct console co, const char b, unsigned count)
	137	{
	138	goldfish_tty_do_write(co->index, b, count);
	139	}
	140
	141	static struct tty_driver goldfish_tty_console_device(struct console c, int *index)
	142	{
	143	*index = c->index;
	144	return goldfish_tty_driver;
	145	}
	146
	147	static int goldfish_tty_console_setup(struct console co, char options)
	148	{
	149	if((unsigned)co->index > goldfish_tty_line_count)
150	return -ENODEV;
151	if(goldfish_ttys[co->index].base == 0)
152	return -ENODEV;
153	return 0;
154	}
155
156	static struct tty_port_operations goldfish_port_ops = {
157	.activate = goldfish_tty_activate,
158	.shutdown = goldfish_tty_shutdown
159	};
160
161	static struct tty_operations goldfish_tty_ops = {
162	.open = goldfish_tty_open,
163	.close = goldfish_tty_close,
164	.hangup = goldfish_tty_hangup,
165	.write = goldfish_tty_write,
166	.write_room = goldfish_tty_write_room,
167	.chars_in_buffer = goldfish_tty_chars_in_buffer,
168	};
169
170	static int goldfish_tty_create_driver(void)
171	{
172	int ret;
173	struct tty_driver *tty;
174
175	goldfish_ttys = kzalloc(sizeof(goldfish_ttys) goldfish_tty_line_count, GFP_KERNEL);
176	if(goldfish_ttys == NULL) {
177	ret = -ENOMEM;
178	goto err_alloc_goldfish_ttys_failed;
179	}
180	tty = alloc_tty_driver(goldfish_tty_line_count);
181	if(tty == NULL) {
182	ret = -ENOMEM;
183	goto err_alloc_tty_driver_failed;
184	}
185	tty->driver_name = "goldfish";
186	tty->name = "ttyGF";
187	tty->type = TTY_DRIVER_TYPE_SERIAL;
188	tty->subtype = SERIAL_TYPE_NORMAL;
189	tty->init_termios = tty_std_termios;
190	tty->flags = TTY_DRIVER_RESET_TERMIOS \| TTY_DRIVER_REAL_RAW \| TTY_DRIVER_DYNAMIC_DEV;
191	tty_set_operations(tty, &goldfish_tty_ops);
192	ret = tty_register_driver(tty);
193	if(ret)
194	goto err_tty_register_driver_failed;
195
196	goldfish_tty_driver = tty;
197	return 0;
198
199	err_tty_register_driver_failed:
200	put_tty_driver(tty);
201	err_alloc_tty_driver_failed:
202	kfree(goldfish_ttys);
203	goldfish_ttys = NULL;
204	err_alloc_goldfish_ttys_failed:
205	return ret;
206	}
207
208	static void goldfish_tty_delete_driver(void)
209	{
210	tty_unregister_driver(goldfish_tty_driver);
211	put_tty_driver(goldfish_tty_driver);
212	goldfish_tty_driver = NULL;
213	kfree(goldfish_ttys);
214	goldfish_ttys = NULL;
215	}
216
217	static int goldfish_tty_probe(struct platform_device *pdev)
218	{
219	struct goldfish_tty *qtty;
220	int ret = -EINVAL;
221	int i;
222	struct resource *r;
223	struct device *ttydev;
224	void __iomem *base;
225	u32 irq;
226
227	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
228	if(r == NULL)
229	return -EINVAL;
230
231	base = ioremap(r->start, 0x1000);
232	if (base == NULL)
233	pr_err("goldfish_tty: unable to remap base\n");
234
235	r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
236	if(r == NULL)
237	goto err_unmap;
238
239	irq = r->start;
240
241	if(pdev->id >= goldfish_tty_line_count)
242	goto err_unmap;
243
244	mutex_lock(&goldfish_tty_lock);
245	if(goldfish_tty_current_line_count == 0) {
246	ret = goldfish_tty_create_driver();
247	if(ret)
248	goto err_create_driver_failed;
249	}
250	goldfish_tty_current_line_count++;
251
252	qtty = &goldfish_ttys[pdev->id];
253	spin_lock_init(&qtty->lock);
254	tty_port_init(&qtty->port);
255	qtty->port.ops = &goldfish_port_ops;
256	qtty->base = base;
257	qtty->irq = irq;
258
259	writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_CMD);
260
261	ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED, "goldfish_tty", pdev);
262	if(ret)
263	goto err_request_irq_failed;
264
265
266	ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver,
267	pdev->id, &pdev->dev);
268	if(IS_ERR(ttydev)) {
269	ret = PTR_ERR(ttydev);
270	goto err_tty_register_device_failed;
271	}
272
273	strcpy(qtty->console.name, "ttyGF");
274	qtty->console.write = goldfish_tty_console_write;
275	qtty->console.device = goldfish_tty_console_device;
276	qtty->console.setup = goldfish_tty_console_setup;
277	qtty->console.flags = CON_PRINTBUFFER;
278	qtty->console.index = pdev->id;
279	register_console(&qtty->console);
280
281	mutex_unlock(&goldfish_tty_lock);
282	return 0;
283
284	tty_unregister_device(goldfish_tty_driver, i);
285	err_tty_register_device_failed:
286	free_irq(irq, pdev);
287	err_request_irq_failed:
288	goldfish_tty_current_line_count--;
289	if(goldfish_tty_current_line_count == 0)
290	goldfish_tty_delete_driver();
291	err_create_driver_failed:
292	mutex_unlock(&goldfish_tty_lock);
293	err_unmap:
294	iounmap(base);
295	return ret;
296	}
297
298	static int goldfish_tty_remove(struct platform_device *pdev)
299	{
300	struct goldfish_tty *qtty;
301
302	mutex_lock(&goldfish_tty_lock);
303
304	qtty = &goldfish_ttys[pdev->id];
305	unregister_console(&qtty->console);
306	tty_unregister_device(goldfish_tty_driver, pdev->id);
307	iounmap(qtty->base);
308	qtty->base = 0;
309	free_irq(qtty->irq, pdev);
310	goldfish_tty_current_line_count--;
311	if(goldfish_tty_current_line_count == 0)
312	goldfish_tty_delete_driver();
313	mutex_unlock(&goldfish_tty_lock);
314	return 0;
315	}
316
317	static struct platform_driver goldfish_tty_platform_driver = {
318	.probe = goldfish_tty_probe,
319	.remove = goldfish_tty_remove,
320	.driver = {
321	.name = "goldfish_tty"
322	}
323	};
324
325	module_platform_driver(goldfish_tty_platform_driver);
326
327	MODULE_LICENSE("GPL v2");