of_serial.c 8.73 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11
/*
 *  Serial Port driver for Open Firmware platform devices
 *
 *    Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 */
12
#include <linux/console.h>
13
#include <linux/module.h>
14
#include <linux/slab.h>
15
#include <linux/delay.h>
16
#include <linux/serial_core.h>
17
#include <linux/serial_reg.h>
Grant Likely's avatar
Grant Likely committed
18
#include <linux/of_address.h>
19
#include <linux/of_irq.h>
20
#include <linux/of_platform.h>
21
#include <linux/nwpserial.h>
22
#include <linux/clk.h>
23

24 25
#include "8250/8250.h"

26
struct of_serial_info {
27
	struct clk *clk;
28 29 30 31
	int type;
	int line;
};

32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
#ifdef CONFIG_ARCH_TEGRA
void tegra_serial_handle_break(struct uart_port *p)
{
	unsigned int status, tmout = 10000;

	do {
		status = p->serial_in(p, UART_LSR);
		if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
			status = p->serial_in(p, UART_RX);
		else
			break;
		if (--tmout == 0)
			break;
		udelay(1);
	} while (1);
}
48 49 50 51
#else
static inline void tegra_serial_handle_break(struct uart_port *port)
{
}
52 53
#endif

54 55 56
/*
 * Fill a struct uart_port for a given device node
 */
57
static int of_platform_serial_setup(struct platform_device *ofdev,
58 59
			int type, struct uart_port *port,
			struct of_serial_info *info)
60 61
{
	struct resource resource;
62
	struct device_node *np = ofdev->dev.of_node;
63 64
	u32 clk, spd, prop;
	int ret;
65 66

	memset(port, 0, sizeof *port);
67
	if (of_property_read_u32(np, "clock-frequency", &clk)) {
68 69 70

		/* Get clk rate through clk driver if present */
		info->clk = clk_get(&ofdev->dev, NULL);
71
		if (IS_ERR(info->clk)) {
72 73
			dev_warn(&ofdev->dev,
				"clk or clock-frequency not defined\n");
74
			return PTR_ERR(info->clk);
75 76 77 78
		}

		clk_prepare_enable(info->clk);
		clk = clk_get_rate(info->clk);
79
	}
80 81 82
	/* If current-speed was set, then try not to change it. */
	if (of_property_read_u32(np, "current-speed", &spd) == 0)
		port->custom_divisor = clk / (16 * spd);
83 84 85 86

	ret = of_address_to_resource(np, 0, &resource);
	if (ret) {
		dev_warn(&ofdev->dev, "invalid address\n");
87
		goto out;
88 89 90 91
	}

	spin_lock_init(&port->lock);
	port->mapbase = resource.start;
92
	port->mapsize = resource_size(&resource);
93 94

	/* Check for shifted address mapping */
95 96
	if (of_property_read_u32(np, "reg-offset", &prop) == 0)
		port->mapbase += prop;
97 98

	/* Check for registers offset within the devices address range */
99 100
	if (of_property_read_u32(np, "reg-shift", &prop) == 0)
		port->regshift = prop;
101

102 103 104 105
	/* Check for fifo size */
	if (of_property_read_u32(np, "fifo-size", &prop) == 0)
		port->fifosize = prop;

106 107 108 109 110
	/* Check for a fixed line number */
	ret = of_alias_get_id(np, "serial");
	if (ret >= 0)
		port->line = ret;

111 112
	port->irq = irq_of_parse_and_map(np, 0);
	port->iotype = UPIO_MEM;
113 114
	if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
		switch (prop) {
115 116 117 118 119 120 121
		case 1:
			port->iotype = UPIO_MEM;
			break;
		case 4:
			port->iotype = UPIO_MEM32;
			break;
		default:
122 123
			dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
				 prop);
124 125
			ret = -EINVAL;
			goto out;
126 127 128
		}
	}

129
	port->type = type;
130
	port->uartclk = clk;
131
	port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
132
		| UPF_FIXED_PORT | UPF_FIXED_TYPE;
133 134 135 136

	if (of_find_property(np, "no-loopback-test", NULL))
		port->flags |= UPF_SKIP_TEST;

137 138
	port->dev = &ofdev->dev;

139 140
	switch (type) {
	case PORT_TEGRA:
141
		port->handle_break = tegra_serial_handle_break;
142 143 144 145 146 147
		break;

	case PORT_RT2880:
		port->iotype = UPIO_AU;
		break;
	}
148

149
	return 0;
150 151 152 153
out:
	if (info->clk)
		clk_disable_unprepare(info->clk);
	return ret;
154 155 156 157 158
}

/*
 * Try to register a serial port
 */
159
static const struct of_device_id of_platform_serial_table[];
160
static int of_platform_serial_probe(struct platform_device *ofdev)
161
{
162
	const struct of_device_id *match;
163
	struct of_serial_info *info;
164 165 166 167
	struct uart_port port;
	int port_type;
	int ret;

168 169
	match = of_match_device(of_platform_serial_table, &ofdev->dev);
	if (!match)
170 171
		return -EINVAL;

172
	if (of_find_property(ofdev->dev.of_node, "used-by-rtas", NULL))
173 174
		return -EBUSY;

175
	info = kzalloc(sizeof(*info), GFP_KERNEL);
176 177 178
	if (info == NULL)
		return -ENOMEM;

179
	port_type = (unsigned long)match->data;
180
	ret = of_platform_serial_setup(ofdev, port_type, &port, info);
181 182 183 184
	if (ret)
		goto out;

	switch (port_type) {
185
#ifdef CONFIG_SERIAL_8250
186
	case PORT_8250 ... PORT_MAX_8250:
187 188 189
	{
		struct uart_8250_port port8250;
		memset(&port8250, 0, sizeof(port8250));
190
		port.type = port_type;
191
		port8250.port = port;
192 193 194 195 196 197 198 199

		if (port.fifosize)
			port8250.capabilities = UART_CAP_FIFO;

		if (of_property_read_bool(ofdev->dev.of_node,
					  "auto-flow-control"))
			port8250.capabilities |= UART_CAP_AFE;

200
		ret = serial8250_register_8250_port(&port8250);
201
		break;
202
	}
203 204 205 206 207 208
#endif
#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
	case PORT_NWPSERIAL:
		ret = nwpserial_register_port(&port);
		break;
#endif
209 210
	default:
		/* need to add code for these */
211 212
	case PORT_UNKNOWN:
		dev_info(&ofdev->dev, "Unknown serial port found, ignored\n");
213 214 215 216 217 218
		ret = -ENODEV;
		break;
	}
	if (ret < 0)
		goto out;

219 220
	info->type = port_type;
	info->line = ret;
221
	platform_set_drvdata(ofdev, info);
222 223
	return 0;
out:
224
	kfree(info);
225 226 227 228 229 230 231
	irq_dispose_mapping(port.irq);
	return ret;
}

/*
 * Release a line
 */
232
static int of_platform_serial_remove(struct platform_device *ofdev)
233
{
234
	struct of_serial_info *info = platform_get_drvdata(ofdev);
235
	switch (info->type) {
236
#ifdef CONFIG_SERIAL_8250
237 238 239
	case PORT_8250 ... PORT_MAX_8250:
		serial8250_unregister_port(info->line);
		break;
240 241 242 243 244 245
#endif
#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
	case PORT_NWPSERIAL:
		nwpserial_unregister_port(info->line);
		break;
#endif
246 247 248 249
	default:
		/* need to add code for these */
		break;
	}
250 251 252

	if (info->clk)
		clk_disable_unprepare(info->clk);
253
	kfree(info);
254 255 256
	return 0;
}

257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320
#ifdef CONFIG_PM_SLEEP
#ifdef CONFIG_SERIAL_8250
static void of_serial_suspend_8250(struct of_serial_info *info)
{
	struct uart_8250_port *port8250 = serial8250_get_port(info->line);
	struct uart_port *port = &port8250->port;

	serial8250_suspend_port(info->line);
	if (info->clk && (!uart_console(port) || console_suspend_enabled))
		clk_disable_unprepare(info->clk);
}

static void of_serial_resume_8250(struct of_serial_info *info)
{
	struct uart_8250_port *port8250 = serial8250_get_port(info->line);
	struct uart_port *port = &port8250->port;

	if (info->clk && (!uart_console(port) || console_suspend_enabled))
		clk_prepare_enable(info->clk);

	serial8250_resume_port(info->line);
}
#else
static inline void of_serial_suspend_8250(struct of_serial_info *info)
{
}

static inline void of_serial_resume_8250(struct of_serial_info *info)
{
}
#endif

static int of_serial_suspend(struct device *dev)
{
	struct of_serial_info *info = dev_get_drvdata(dev);

	switch (info->type) {
	case PORT_8250 ... PORT_MAX_8250:
		of_serial_suspend_8250(info);
		break;
	default:
		break;
	}

	return 0;
}

static int of_serial_resume(struct device *dev)
{
	struct of_serial_info *info = dev_get_drvdata(dev);

	switch (info->type) {
	case PORT_8250 ... PORT_MAX_8250:
		of_serial_resume_8250(info);
		break;
	default:
		break;
	}

	return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(of_serial_pm_ops, of_serial_suspend, of_serial_resume);

321 322 323
/*
 * A few common types, add more as needed.
 */
324
static const struct of_device_id of_platform_serial_table[] = {
325 326 327 328 329 330
	{ .compatible = "ns8250",   .data = (void *)PORT_8250, },
	{ .compatible = "ns16450",  .data = (void *)PORT_16450, },
	{ .compatible = "ns16550a", .data = (void *)PORT_16550A, },
	{ .compatible = "ns16550",  .data = (void *)PORT_16550, },
	{ .compatible = "ns16750",  .data = (void *)PORT_16750, },
	{ .compatible = "ns16850",  .data = (void *)PORT_16850, },
331
	{ .compatible = "nvidia,tegra20-uart", .data = (void *)PORT_TEGRA, },
332
	{ .compatible = "nxp,lpc3220-uart", .data = (void *)PORT_LPC3220, },
333
	{ .compatible = "ralink,rt2880-uart", .data = (void *)PORT_RT2880, },
334 335 336 337 338 339
	{ .compatible = "altr,16550-FIFO32",
		.data = (void *)PORT_ALTR_16550_F32, },
	{ .compatible = "altr,16550-FIFO64",
		.data = (void *)PORT_ALTR_16550_F64, },
	{ .compatible = "altr,16550-FIFO128",
		.data = (void *)PORT_ALTR_16550_F128, },
340 341 342 343
	{ .compatible = "mrvl,mmp-uart",
		.data = (void *)PORT_XSCALE, },
	{ .compatible = "mrvl,pxa-uart",
		.data = (void *)PORT_XSCALE, },
344
#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
345 346
	{ .compatible = "ibm,qpace-nwp-serial",
		.data = (void *)PORT_NWPSERIAL, },
347
#endif
348
	{ .type = "serial",         .data = (void *)PORT_UNKNOWN, },
349 350 351
	{ /* end of list */ },
};

352
static struct platform_driver of_platform_serial_driver = {
353 354 355 356
	.driver = {
		.name = "of_serial",
		.of_match_table = of_platform_serial_table,
	},
357 358 359 360
	.probe = of_platform_serial_probe,
	.remove = of_platform_serial_remove,
};

361
module_platform_driver(of_platform_serial_driver);
362 363 364 365

MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");