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v5.14.15
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * LiteUART serial controller (LiteX) Driver
  4 *
  5 * Copyright (C) 2019-2020 Antmicro <www.antmicro.com>
  6 */
  7
  8#include <linux/console.h>
  9#include <linux/litex.h>
 10#include <linux/module.h>
 11#include <linux/of.h>
 12#include <linux/of_address.h>
 13#include <linux/of_platform.h>
 14#include <linux/serial.h>
 15#include <linux/serial_core.h>
 16#include <linux/slab.h>
 17#include <linux/timer.h>
 18#include <linux/tty_flip.h>
 19#include <linux/xarray.h>
 20
 21/*
 22 * CSRs definitions (base address offsets + width)
 23 *
 24 * The definitions below are true for LiteX SoC configured for 8-bit CSR Bus,
 25 * 32-bit aligned.
 26 *
 27 * Supporting other configurations might require new definitions or a more
 28 * generic way of indexing the LiteX CSRs.
 29 *
 30 * For more details on how CSRs are defined and handled in LiteX, see comments
 31 * in the LiteX SoC Driver: drivers/soc/litex/litex_soc_ctrl.c
 32 */
 33#define OFF_RXTX	0x00
 34#define OFF_TXFULL	0x04
 35#define OFF_RXEMPTY	0x08
 36#define OFF_EV_STATUS	0x0c
 37#define OFF_EV_PENDING	0x10
 38#define OFF_EV_ENABLE	0x14
 39
 40/* events */
 41#define EV_TX		0x1
 42#define EV_RX		0x2
 43
 44struct liteuart_port {
 45	struct uart_port port;
 46	struct timer_list timer;
 47	u32 id;
 48};
 49
 50#define to_liteuart_port(port)	container_of(port, struct liteuart_port, port)
 51
 52static DEFINE_XARRAY_FLAGS(liteuart_array, XA_FLAGS_ALLOC);
 53
 54#ifdef CONFIG_SERIAL_LITEUART_CONSOLE
 55static struct console liteuart_console;
 56#endif
 57
 58static struct uart_driver liteuart_driver = {
 59	.owner = THIS_MODULE,
 60	.driver_name = "liteuart",
 61	.dev_name = "ttyLXU",
 62	.major = 0,
 63	.minor = 0,
 64	.nr = CONFIG_SERIAL_LITEUART_MAX_PORTS,
 65#ifdef CONFIG_SERIAL_LITEUART_CONSOLE
 66	.cons = &liteuart_console,
 67#endif
 68};
 69
 70static void liteuart_timer(struct timer_list *t)
 71{
 72	struct liteuart_port *uart = from_timer(uart, t, timer);
 73	struct uart_port *port = &uart->port;
 74	unsigned char __iomem *membase = port->membase;
 75	unsigned int flg = TTY_NORMAL;
 76	int ch;
 77	unsigned long status;
 78
 79	while ((status = !litex_read8(membase + OFF_RXEMPTY)) == 1) {
 80		ch = litex_read8(membase + OFF_RXTX);
 81		port->icount.rx++;
 82
 83		/* necessary for RXEMPTY to refresh its value */
 84		litex_write8(membase + OFF_EV_PENDING, EV_TX | EV_RX);
 85
 86		/* no overflow bits in status */
 87		if (!(uart_handle_sysrq_char(port, ch)))
 88			uart_insert_char(port, status, 0, ch, flg);
 89
 90		tty_flip_buffer_push(&port->state->port);
 91	}
 92
 93	mod_timer(&uart->timer, jiffies + uart_poll_timeout(port));
 94}
 95
 96static void liteuart_putchar(struct uart_port *port, int ch)
 97{
 98	while (litex_read8(port->membase + OFF_TXFULL))
 99		cpu_relax();
100
101	litex_write8(port->membase + OFF_RXTX, ch);
102}
103
104static unsigned int liteuart_tx_empty(struct uart_port *port)
105{
106	/* not really tx empty, just checking if tx is not full */
107	if (!litex_read8(port->membase + OFF_TXFULL))
108		return TIOCSER_TEMT;
109
110	return 0;
111}
112
113static void liteuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
114{
115	/* modem control register is not present in LiteUART */
116}
117
118static unsigned int liteuart_get_mctrl(struct uart_port *port)
119{
120	return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
121}
122
123static void liteuart_stop_tx(struct uart_port *port)
124{
125}
126
127static void liteuart_start_tx(struct uart_port *port)
128{
129	struct circ_buf *xmit = &port->state->xmit;
130	unsigned char ch;
131
132	if (unlikely(port->x_char)) {
133		litex_write8(port->membase + OFF_RXTX, port->x_char);
134		port->icount.tx++;
135		port->x_char = 0;
136	} else if (!uart_circ_empty(xmit)) {
137		while (xmit->head != xmit->tail) {
138			ch = xmit->buf[xmit->tail];
139			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
140			port->icount.tx++;
141			liteuart_putchar(port, ch);
142		}
143	}
144
145	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
146		uart_write_wakeup(port);
147}
148
149static void liteuart_stop_rx(struct uart_port *port)
150{
151	struct liteuart_port *uart = to_liteuart_port(port);
152
153	/* just delete timer */
154	del_timer(&uart->timer);
155}
156
157static void liteuart_break_ctl(struct uart_port *port, int break_state)
158{
159	/* LiteUART doesn't support sending break signal */
160}
161
162static int liteuart_startup(struct uart_port *port)
163{
164	struct liteuart_port *uart = to_liteuart_port(port);
165
166	/* disable events */
167	litex_write8(port->membase + OFF_EV_ENABLE, 0);
168
169	/* prepare timer for polling */
170	timer_setup(&uart->timer, liteuart_timer, 0);
171	mod_timer(&uart->timer, jiffies + uart_poll_timeout(port));
172
173	return 0;
174}
175
176static void liteuart_shutdown(struct uart_port *port)
177{
178}
179
180static void liteuart_set_termios(struct uart_port *port, struct ktermios *new,
181				 struct ktermios *old)
182{
183	unsigned int baud;
184	unsigned long flags;
185
186	spin_lock_irqsave(&port->lock, flags);
187
188	/* update baudrate */
189	baud = uart_get_baud_rate(port, new, old, 0, 460800);
190	uart_update_timeout(port, new->c_cflag, baud);
191
192	spin_unlock_irqrestore(&port->lock, flags);
193}
194
195static const char *liteuart_type(struct uart_port *port)
196{
197	return "liteuart";
198}
199
200static void liteuart_release_port(struct uart_port *port)
201{
202}
203
204static int liteuart_request_port(struct uart_port *port)
205{
206	return 0;
207}
208
209static void liteuart_config_port(struct uart_port *port, int flags)
210{
211	/*
212	 * Driver core for serial ports forces a non-zero value for port type.
213	 * Write an arbitrary value here to accommodate the serial core driver,
214	 * as ID part of UAPI is redundant.
215	 */
216	port->type = 1;
217}
218
219static int liteuart_verify_port(struct uart_port *port,
220				struct serial_struct *ser)
221{
222	if (port->type != PORT_UNKNOWN && ser->type != 1)
223		return -EINVAL;
224
225	return 0;
226}
227
228static const struct uart_ops liteuart_ops = {
229	.tx_empty	= liteuart_tx_empty,
230	.set_mctrl	= liteuart_set_mctrl,
231	.get_mctrl	= liteuart_get_mctrl,
232	.stop_tx	= liteuart_stop_tx,
233	.start_tx	= liteuart_start_tx,
234	.stop_rx	= liteuart_stop_rx,
235	.break_ctl	= liteuart_break_ctl,
236	.startup	= liteuart_startup,
237	.shutdown	= liteuart_shutdown,
238	.set_termios	= liteuart_set_termios,
239	.type		= liteuart_type,
240	.release_port	= liteuart_release_port,
241	.request_port	= liteuart_request_port,
242	.config_port	= liteuart_config_port,
243	.verify_port	= liteuart_verify_port,
244};
245
246static int liteuart_probe(struct platform_device *pdev)
247{
248	struct liteuart_port *uart;
249	struct uart_port *port;
250	struct xa_limit limit;
251	int dev_id, ret;
252
253	/* look for aliases; auto-enumerate for free index if not found */
254	dev_id = of_alias_get_id(pdev->dev.of_node, "serial");
255	if (dev_id < 0)
256		limit = XA_LIMIT(0, CONFIG_SERIAL_LITEUART_MAX_PORTS);
257	else
258		limit = XA_LIMIT(dev_id, dev_id);
259
260	uart = devm_kzalloc(&pdev->dev, sizeof(struct liteuart_port), GFP_KERNEL);
261	if (!uart)
262		return -ENOMEM;
263
264	ret = xa_alloc(&liteuart_array, &dev_id, uart, limit, GFP_KERNEL);
265	if (ret)
266		return ret;
267
268	uart->id = dev_id;
269	port = &uart->port;
270
271	/* get membase */
272	port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
273	if (IS_ERR(port->membase))
274		return PTR_ERR(port->membase);
 
 
275
276	/* values not from device tree */
277	port->dev = &pdev->dev;
278	port->iotype = UPIO_MEM;
279	port->flags = UPF_BOOT_AUTOCONF;
280	port->ops = &liteuart_ops;
281	port->regshift = 2;
282	port->fifosize = 16;
283	port->iobase = 1;
284	port->type = PORT_UNKNOWN;
285	port->line = dev_id;
286	spin_lock_init(&port->lock);
287
288	return uart_add_one_port(&liteuart_driver, &uart->port);
 
 
 
 
 
 
 
 
 
 
 
289}
290
291static int liteuart_remove(struct platform_device *pdev)
292{
293	struct uart_port *port = platform_get_drvdata(pdev);
294	struct liteuart_port *uart = to_liteuart_port(port);
295
 
296	xa_erase(&liteuart_array, uart->id);
297
298	return 0;
299}
300
301static const struct of_device_id liteuart_of_match[] = {
302	{ .compatible = "litex,liteuart" },
303	{}
304};
305MODULE_DEVICE_TABLE(of, liteuart_of_match);
306
307static struct platform_driver liteuart_platform_driver = {
308	.probe = liteuart_probe,
309	.remove = liteuart_remove,
310	.driver = {
311		.name = "liteuart",
312		.of_match_table = liteuart_of_match,
313	},
314};
315
316#ifdef CONFIG_SERIAL_LITEUART_CONSOLE
317
318static void liteuart_console_write(struct console *co, const char *s,
319	unsigned int count)
320{
321	struct liteuart_port *uart;
322	struct uart_port *port;
323	unsigned long flags;
324
325	uart = (struct liteuart_port *)xa_load(&liteuart_array, co->index);
326	port = &uart->port;
327
328	spin_lock_irqsave(&port->lock, flags);
329	uart_console_write(port, s, count, liteuart_putchar);
330	spin_unlock_irqrestore(&port->lock, flags);
331}
332
333static int liteuart_console_setup(struct console *co, char *options)
334{
335	struct liteuart_port *uart;
336	struct uart_port *port;
337	int baud = 115200;
338	int bits = 8;
339	int parity = 'n';
340	int flow = 'n';
341
342	uart = (struct liteuart_port *)xa_load(&liteuart_array, co->index);
343	if (!uart)
344		return -ENODEV;
345
346	port = &uart->port;
347	if (!port->membase)
348		return -ENODEV;
349
350	if (options)
351		uart_parse_options(options, &baud, &parity, &bits, &flow);
352
353	return uart_set_options(port, co, baud, parity, bits, flow);
354}
355
356static struct console liteuart_console = {
357	.name = "liteuart",
358	.write = liteuart_console_write,
359	.device = uart_console_device,
360	.setup = liteuart_console_setup,
361	.flags = CON_PRINTBUFFER,
362	.index = -1,
363	.data = &liteuart_driver,
364};
365
366static int __init liteuart_console_init(void)
367{
368	register_console(&liteuart_console);
369
370	return 0;
371}
372console_initcall(liteuart_console_init);
373
374static void early_liteuart_write(struct console *console, const char *s,
375				    unsigned int count)
376{
377	struct earlycon_device *device = console->data;
378	struct uart_port *port = &device->port;
379
380	uart_console_write(port, s, count, liteuart_putchar);
381}
382
383static int __init early_liteuart_setup(struct earlycon_device *device,
384				       const char *options)
385{
386	if (!device->port.membase)
387		return -ENODEV;
388
389	device->con->write = early_liteuart_write;
390	return 0;
391}
392
393OF_EARLYCON_DECLARE(liteuart, "litex,liteuart", early_liteuart_setup);
394#endif /* CONFIG_SERIAL_LITEUART_CONSOLE */
395
396static int __init liteuart_init(void)
397{
398	int res;
399
400	res = uart_register_driver(&liteuart_driver);
401	if (res)
402		return res;
403
404	res = platform_driver_register(&liteuart_platform_driver);
405	if (res) {
406		uart_unregister_driver(&liteuart_driver);
407		return res;
408	}
409
410	return 0;
411}
412
413static void __exit liteuart_exit(void)
414{
415	platform_driver_unregister(&liteuart_platform_driver);
416	uart_unregister_driver(&liteuart_driver);
417}
418
419module_init(liteuart_init);
420module_exit(liteuart_exit);
421
422MODULE_AUTHOR("Antmicro <www.antmicro.com>");
423MODULE_DESCRIPTION("LiteUART serial driver");
424MODULE_LICENSE("GPL v2");
425MODULE_ALIAS("platform: liteuart");
v6.2
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * LiteUART serial controller (LiteX) Driver
  4 *
  5 * Copyright (C) 2019-2020 Antmicro <www.antmicro.com>
  6 */
  7
  8#include <linux/console.h>
  9#include <linux/litex.h>
 10#include <linux/module.h>
 11#include <linux/of.h>
 12#include <linux/of_address.h>
 13#include <linux/of_platform.h>
 14#include <linux/serial.h>
 15#include <linux/serial_core.h>
 16#include <linux/slab.h>
 17#include <linux/timer.h>
 18#include <linux/tty_flip.h>
 19#include <linux/xarray.h>
 20
 21/*
 22 * CSRs definitions (base address offsets + width)
 23 *
 24 * The definitions below are true for LiteX SoC configured for 8-bit CSR Bus,
 25 * 32-bit aligned.
 26 *
 27 * Supporting other configurations might require new definitions or a more
 28 * generic way of indexing the LiteX CSRs.
 29 *
 30 * For more details on how CSRs are defined and handled in LiteX, see comments
 31 * in the LiteX SoC Driver: drivers/soc/litex/litex_soc_ctrl.c
 32 */
 33#define OFF_RXTX	0x00
 34#define OFF_TXFULL	0x04
 35#define OFF_RXEMPTY	0x08
 36#define OFF_EV_STATUS	0x0c
 37#define OFF_EV_PENDING	0x10
 38#define OFF_EV_ENABLE	0x14
 39
 40/* events */
 41#define EV_TX		0x1
 42#define EV_RX		0x2
 43
 44struct liteuart_port {
 45	struct uart_port port;
 46	struct timer_list timer;
 47	u32 id;
 48};
 49
 50#define to_liteuart_port(port)	container_of(port, struct liteuart_port, port)
 51
 52static DEFINE_XARRAY_FLAGS(liteuart_array, XA_FLAGS_ALLOC);
 53
 54#ifdef CONFIG_SERIAL_LITEUART_CONSOLE
 55static struct console liteuart_console;
 56#endif
 57
 58static struct uart_driver liteuart_driver = {
 59	.owner = THIS_MODULE,
 60	.driver_name = "liteuart",
 61	.dev_name = "ttyLXU",
 62	.major = 0,
 63	.minor = 0,
 64	.nr = CONFIG_SERIAL_LITEUART_MAX_PORTS,
 65#ifdef CONFIG_SERIAL_LITEUART_CONSOLE
 66	.cons = &liteuart_console,
 67#endif
 68};
 69
 70static void liteuart_timer(struct timer_list *t)
 71{
 72	struct liteuart_port *uart = from_timer(uart, t, timer);
 73	struct uart_port *port = &uart->port;
 74	unsigned char __iomem *membase = port->membase;
 75	unsigned int flg = TTY_NORMAL;
 76	int ch;
 77	unsigned long status;
 78
 79	while ((status = !litex_read8(membase + OFF_RXEMPTY)) == 1) {
 80		ch = litex_read8(membase + OFF_RXTX);
 81		port->icount.rx++;
 82
 83		/* necessary for RXEMPTY to refresh its value */
 84		litex_write8(membase + OFF_EV_PENDING, EV_TX | EV_RX);
 85
 86		/* no overflow bits in status */
 87		if (!(uart_handle_sysrq_char(port, ch)))
 88			uart_insert_char(port, status, 0, ch, flg);
 89
 90		tty_flip_buffer_push(&port->state->port);
 91	}
 92
 93	mod_timer(&uart->timer, jiffies + uart_poll_timeout(port));
 94}
 95
 96static void liteuart_putchar(struct uart_port *port, unsigned char ch)
 97{
 98	while (litex_read8(port->membase + OFF_TXFULL))
 99		cpu_relax();
100
101	litex_write8(port->membase + OFF_RXTX, ch);
102}
103
104static unsigned int liteuart_tx_empty(struct uart_port *port)
105{
106	/* not really tx empty, just checking if tx is not full */
107	if (!litex_read8(port->membase + OFF_TXFULL))
108		return TIOCSER_TEMT;
109
110	return 0;
111}
112
113static void liteuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
114{
115	/* modem control register is not present in LiteUART */
116}
117
118static unsigned int liteuart_get_mctrl(struct uart_port *port)
119{
120	return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
121}
122
123static void liteuart_stop_tx(struct uart_port *port)
124{
125}
126
127static void liteuart_start_tx(struct uart_port *port)
128{
129	struct circ_buf *xmit = &port->state->xmit;
130	unsigned char ch;
131
132	if (unlikely(port->x_char)) {
133		litex_write8(port->membase + OFF_RXTX, port->x_char);
134		port->icount.tx++;
135		port->x_char = 0;
136	} else if (!uart_circ_empty(xmit)) {
137		while (xmit->head != xmit->tail) {
138			ch = xmit->buf[xmit->tail];
139			uart_xmit_advance(port, 1);
 
140			liteuart_putchar(port, ch);
141		}
142	}
143
144	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
145		uart_write_wakeup(port);
146}
147
148static void liteuart_stop_rx(struct uart_port *port)
149{
150	struct liteuart_port *uart = to_liteuart_port(port);
151
152	/* just delete timer */
153	del_timer(&uart->timer);
154}
155
156static void liteuart_break_ctl(struct uart_port *port, int break_state)
157{
158	/* LiteUART doesn't support sending break signal */
159}
160
161static int liteuart_startup(struct uart_port *port)
162{
163	struct liteuart_port *uart = to_liteuart_port(port);
164
165	/* disable events */
166	litex_write8(port->membase + OFF_EV_ENABLE, 0);
167
168	/* prepare timer for polling */
169	timer_setup(&uart->timer, liteuart_timer, 0);
170	mod_timer(&uart->timer, jiffies + uart_poll_timeout(port));
171
172	return 0;
173}
174
175static void liteuart_shutdown(struct uart_port *port)
176{
177}
178
179static void liteuart_set_termios(struct uart_port *port, struct ktermios *new,
180				 const struct ktermios *old)
181{
182	unsigned int baud;
183	unsigned long flags;
184
185	spin_lock_irqsave(&port->lock, flags);
186
187	/* update baudrate */
188	baud = uart_get_baud_rate(port, new, old, 0, 460800);
189	uart_update_timeout(port, new->c_cflag, baud);
190
191	spin_unlock_irqrestore(&port->lock, flags);
192}
193
194static const char *liteuart_type(struct uart_port *port)
195{
196	return "liteuart";
197}
198
199static void liteuart_release_port(struct uart_port *port)
200{
201}
202
203static int liteuart_request_port(struct uart_port *port)
204{
205	return 0;
206}
207
208static void liteuart_config_port(struct uart_port *port, int flags)
209{
210	/*
211	 * Driver core for serial ports forces a non-zero value for port type.
212	 * Write an arbitrary value here to accommodate the serial core driver,
213	 * as ID part of UAPI is redundant.
214	 */
215	port->type = 1;
216}
217
218static int liteuart_verify_port(struct uart_port *port,
219				struct serial_struct *ser)
220{
221	if (port->type != PORT_UNKNOWN && ser->type != 1)
222		return -EINVAL;
223
224	return 0;
225}
226
227static const struct uart_ops liteuart_ops = {
228	.tx_empty	= liteuart_tx_empty,
229	.set_mctrl	= liteuart_set_mctrl,
230	.get_mctrl	= liteuart_get_mctrl,
231	.stop_tx	= liteuart_stop_tx,
232	.start_tx	= liteuart_start_tx,
233	.stop_rx	= liteuart_stop_rx,
234	.break_ctl	= liteuart_break_ctl,
235	.startup	= liteuart_startup,
236	.shutdown	= liteuart_shutdown,
237	.set_termios	= liteuart_set_termios,
238	.type		= liteuart_type,
239	.release_port	= liteuart_release_port,
240	.request_port	= liteuart_request_port,
241	.config_port	= liteuart_config_port,
242	.verify_port	= liteuart_verify_port,
243};
244
245static int liteuart_probe(struct platform_device *pdev)
246{
247	struct liteuart_port *uart;
248	struct uart_port *port;
249	struct xa_limit limit;
250	int dev_id, ret;
251
252	/* look for aliases; auto-enumerate for free index if not found */
253	dev_id = of_alias_get_id(pdev->dev.of_node, "serial");
254	if (dev_id < 0)
255		limit = XA_LIMIT(0, CONFIG_SERIAL_LITEUART_MAX_PORTS);
256	else
257		limit = XA_LIMIT(dev_id, dev_id);
258
259	uart = devm_kzalloc(&pdev->dev, sizeof(struct liteuart_port), GFP_KERNEL);
260	if (!uart)
261		return -ENOMEM;
262
263	ret = xa_alloc(&liteuart_array, &dev_id, uart, limit, GFP_KERNEL);
264	if (ret)
265		return ret;
266
267	uart->id = dev_id;
268	port = &uart->port;
269
270	/* get membase */
271	port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
272	if (IS_ERR(port->membase)) {
273		ret = PTR_ERR(port->membase);
274		goto err_erase_id;
275	}
276
277	/* values not from device tree */
278	port->dev = &pdev->dev;
279	port->iotype = UPIO_MEM;
280	port->flags = UPF_BOOT_AUTOCONF;
281	port->ops = &liteuart_ops;
282	port->regshift = 2;
283	port->fifosize = 16;
284	port->iobase = 1;
285	port->type = PORT_UNKNOWN;
286	port->line = dev_id;
287	spin_lock_init(&port->lock);
288
289	platform_set_drvdata(pdev, port);
290
291	ret = uart_add_one_port(&liteuart_driver, &uart->port);
292	if (ret)
293		goto err_erase_id;
294
295	return 0;
296
297err_erase_id:
298	xa_erase(&liteuart_array, uart->id);
299
300	return ret;
301}
302
303static int liteuart_remove(struct platform_device *pdev)
304{
305	struct uart_port *port = platform_get_drvdata(pdev);
306	struct liteuart_port *uart = to_liteuart_port(port);
307
308	uart_remove_one_port(&liteuart_driver, port);
309	xa_erase(&liteuart_array, uart->id);
310
311	return 0;
312}
313
314static const struct of_device_id liteuart_of_match[] = {
315	{ .compatible = "litex,liteuart" },
316	{}
317};
318MODULE_DEVICE_TABLE(of, liteuart_of_match);
319
320static struct platform_driver liteuart_platform_driver = {
321	.probe = liteuart_probe,
322	.remove = liteuart_remove,
323	.driver = {
324		.name = "liteuart",
325		.of_match_table = liteuart_of_match,
326	},
327};
328
329#ifdef CONFIG_SERIAL_LITEUART_CONSOLE
330
331static void liteuart_console_write(struct console *co, const char *s,
332	unsigned int count)
333{
334	struct liteuart_port *uart;
335	struct uart_port *port;
336	unsigned long flags;
337
338	uart = (struct liteuart_port *)xa_load(&liteuart_array, co->index);
339	port = &uart->port;
340
341	spin_lock_irqsave(&port->lock, flags);
342	uart_console_write(port, s, count, liteuart_putchar);
343	spin_unlock_irqrestore(&port->lock, flags);
344}
345
346static int liteuart_console_setup(struct console *co, char *options)
347{
348	struct liteuart_port *uart;
349	struct uart_port *port;
350	int baud = 115200;
351	int bits = 8;
352	int parity = 'n';
353	int flow = 'n';
354
355	uart = (struct liteuart_port *)xa_load(&liteuart_array, co->index);
356	if (!uart)
357		return -ENODEV;
358
359	port = &uart->port;
360	if (!port->membase)
361		return -ENODEV;
362
363	if (options)
364		uart_parse_options(options, &baud, &parity, &bits, &flow);
365
366	return uart_set_options(port, co, baud, parity, bits, flow);
367}
368
369static struct console liteuart_console = {
370	.name = "liteuart",
371	.write = liteuart_console_write,
372	.device = uart_console_device,
373	.setup = liteuart_console_setup,
374	.flags = CON_PRINTBUFFER,
375	.index = -1,
376	.data = &liteuart_driver,
377};
378
379static int __init liteuart_console_init(void)
380{
381	register_console(&liteuart_console);
382
383	return 0;
384}
385console_initcall(liteuart_console_init);
386
387static void early_liteuart_write(struct console *console, const char *s,
388				    unsigned int count)
389{
390	struct earlycon_device *device = console->data;
391	struct uart_port *port = &device->port;
392
393	uart_console_write(port, s, count, liteuart_putchar);
394}
395
396static int __init early_liteuart_setup(struct earlycon_device *device,
397				       const char *options)
398{
399	if (!device->port.membase)
400		return -ENODEV;
401
402	device->con->write = early_liteuart_write;
403	return 0;
404}
405
406OF_EARLYCON_DECLARE(liteuart, "litex,liteuart", early_liteuart_setup);
407#endif /* CONFIG_SERIAL_LITEUART_CONSOLE */
408
409static int __init liteuart_init(void)
410{
411	int res;
412
413	res = uart_register_driver(&liteuart_driver);
414	if (res)
415		return res;
416
417	res = platform_driver_register(&liteuart_platform_driver);
418	if (res) {
419		uart_unregister_driver(&liteuart_driver);
420		return res;
421	}
422
423	return 0;
424}
425
426static void __exit liteuart_exit(void)
427{
428	platform_driver_unregister(&liteuart_platform_driver);
429	uart_unregister_driver(&liteuart_driver);
430}
431
432module_init(liteuart_init);
433module_exit(liteuart_exit);
434
435MODULE_AUTHOR("Antmicro <www.antmicro.com>");
436MODULE_DESCRIPTION("LiteUART serial driver");
437MODULE_LICENSE("GPL v2");
438MODULE_ALIAS("platform:liteuart");