goldfish.c 8.66 KB
Newer Older
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
/*
 * 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>
Alan's avatar
Alan committed
24
#include <linux/goldfish.h>
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
25 26 27 28 29 30 31 32

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,
33
	GOLDFISH_TTY_DATA_PTR_HIGH  = 0x18,
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61

	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);
62
	gf_write_ptr(buf, base + GOLDFISH_TTY_DATA_PTR,
Alan's avatar
Alan committed
63
				base + GOLDFISH_TTY_DATA_PTR_HIGH);
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
64 65 66 67 68 69 70 71 72 73 74 75 76 77 78
	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);
79
	if (count == 0)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
80 81
		return IRQ_NONE;

82 83
	count = tty_prepare_flip_string(&qtty->port, &buf, count);
	spin_lock_irqsave(&qtty->lock, irq_flags);
84
	gf_write_ptr(buf, base + GOLDFISH_TTY_DATA_PTR,
Alan's avatar
Alan committed
85
				base + GOLDFISH_TTY_DATA_PTR_HIGH);
86 87 88 89
	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);
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
90 91 92 93 94
	return IRQ_HANDLED;
}

static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty)
{
95 96
	struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
									port);
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
97 98 99 100 101 102
	writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_CMD);
	return 0;
}

static void goldfish_tty_shutdown(struct tty_port *port)
{
103 104
	struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
									port);
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
105 106 107
	writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_CMD);
}

108
static int goldfish_tty_open(struct tty_struct *tty, struct file *filp)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
109 110 111 112 113
{
	struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
	return tty_port_open(&qtty->port, tty, filp);
}

114
static void goldfish_tty_close(struct tty_struct *tty, struct file *filp)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
115 116 117 118 119 120 121 122 123
{
	tty_port_close(tty->port, tty, filp);
}

static void goldfish_tty_hangup(struct tty_struct *tty)
{
	tty_port_hangup(tty->port);
}

124 125
static int goldfish_tty_write(struct tty_struct *tty, const unsigned char *buf,
								int count)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142
{
	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);
}

143 144
static void goldfish_tty_console_write(struct console *co, const char *b,
								unsigned count)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
145 146 147 148
{
	goldfish_tty_do_write(co->index, b, count);
}

149 150
static struct tty_driver *goldfish_tty_console_device(struct console *c,
								int *index)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
151 152 153 154 155 156 157
{
	*index = c->index;
	return goldfish_tty_driver;
}

static int goldfish_tty_console_setup(struct console *co, char *options)
{
158
	if ((unsigned)co->index >= goldfish_tty_line_count)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
159
		return -ENODEV;
160
	if (!goldfish_ttys[co->index].base)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
161 162 163 164 165 166 167 168 169
		return -ENODEV;
	return 0;
}

static struct tty_port_operations goldfish_port_ops = {
	.activate = goldfish_tty_activate,
	.shutdown = goldfish_tty_shutdown
};

170
static const struct tty_operations goldfish_tty_ops = {
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
171 172 173 174 175 176 177 178 179 180 181 182 183
	.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;

184 185 186
	goldfish_ttys = kzalloc(sizeof(*goldfish_ttys) *
				goldfish_tty_line_count, GFP_KERNEL);
	if (goldfish_ttys == NULL) {
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
187 188 189 190
		ret = -ENOMEM;
		goto err_alloc_goldfish_ttys_failed;
	}
	tty = alloc_tty_driver(goldfish_tty_line_count);
191
	if (tty == NULL) {
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
192 193 194 195 196 197 198 199
		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;
200 201
	tty->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
						TTY_DRIVER_DYNAMIC_DEV;
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
202 203
	tty_set_operations(tty, &goldfish_tty_ops);
	ret = tty_register_driver(tty);
204
	if (ret)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237
		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);
238
	if (r == NULL)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
239 240 241 242 243 244 245
		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);
246
	if (r == NULL)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
247 248 249 250
		goto err_unmap;

	irq = r->start;

251
	if (pdev->id >= goldfish_tty_line_count)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
252 253 254
		goto err_unmap;

	mutex_lock(&goldfish_tty_lock);
255
	if (goldfish_tty_current_line_count == 0) {
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
256
		ret = goldfish_tty_create_driver();
257
		if (ret)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
258 259 260 261 262 263 264 265 266 267 268 269 270
			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);

271 272 273
	ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED,
						"goldfish_tty", pdev);
	if (ret)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
274 275 276 277 278
		goto err_request_irq_failed;


	ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver,
							pdev->id, &pdev->dev);
279
	if (IS_ERR(ttydev)) {
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295
		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:
296
	free_irq(irq, pdev);
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
297 298
err_request_irq_failed:
	goldfish_tty_current_line_count--;
299
	if (goldfish_tty_current_line_count == 0)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317
		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);
318
	qtty->base = NULL;
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
319 320
	free_irq(qtty->irq, pdev);
	goldfish_tty_current_line_count--;
321
	if (goldfish_tty_current_line_count == 0)
Arve Hjønnevåg's avatar
Arve Hjønnevåg committed
322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337
		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");