2 * Based on meson_uart.c, by AMLOGIC, INC.
4 * Copyright (C) 2014 Carlo Caione <carlo@caione.org>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published
8 * by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
17 #include <linux/clk.h>
18 #include <linux/console.h>
19 #include <linux/delay.h>
20 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/kernel.h>
25 #include <linux/platform_device.h>
26 #include <linux/serial.h>
27 #include <linux/serial_core.h>
28 #include <linux/tty.h>
29 #include <linux/tty_flip.h>
31 /* Register offsets */
32 #define AML_UART_WFIFO 0x00
33 #define AML_UART_RFIFO 0x04
34 #define AML_UART_CONTROL 0x08
35 #define AML_UART_STATUS 0x0c
36 #define AML_UART_MISC 0x10
37 #define AML_UART_REG5 0x14
39 /* AML_UART_CONTROL bits */
40 #define AML_UART_TX_EN BIT(12)
41 #define AML_UART_RX_EN BIT(13)
42 #define AML_UART_TX_RST BIT(22)
43 #define AML_UART_RX_RST BIT(23)
44 #define AML_UART_CLR_ERR BIT(24)
45 #define AML_UART_RX_INT_EN BIT(27)
46 #define AML_UART_TX_INT_EN BIT(28)
47 #define AML_UART_DATA_LEN_MASK (0x03 << 20)
48 #define AML_UART_DATA_LEN_8BIT (0x00 << 20)
49 #define AML_UART_DATA_LEN_7BIT (0x01 << 20)
50 #define AML_UART_DATA_LEN_6BIT (0x02 << 20)
51 #define AML_UART_DATA_LEN_5BIT (0x03 << 20)
53 /* AML_UART_STATUS bits */
54 #define AML_UART_PARITY_ERR BIT(16)
55 #define AML_UART_FRAME_ERR BIT(17)
56 #define AML_UART_TX_FIFO_WERR BIT(18)
57 #define AML_UART_RX_EMPTY BIT(20)
58 #define AML_UART_TX_FULL BIT(21)
59 #define AML_UART_TX_EMPTY BIT(22)
60 #define AML_UART_XMIT_BUSY BIT(25)
61 #define AML_UART_ERR (AML_UART_PARITY_ERR | \
62 AML_UART_FRAME_ERR | \
63 AML_UART_TX_FIFO_WERR)
65 /* AML_UART_CONTROL bits */
66 #define AML_UART_TWO_WIRE_EN BIT(15)
67 #define AML_UART_PARITY_TYPE BIT(18)
68 #define AML_UART_PARITY_EN BIT(19)
69 #define AML_UART_CLEAR_ERR BIT(24)
70 #define AML_UART_STOP_BIN_LEN_MASK (0x03 << 16)
71 #define AML_UART_STOP_BIN_1SB (0x00 << 16)
72 #define AML_UART_STOP_BIN_2SB (0x01 << 16)
74 /* AML_UART_MISC bits */
75 #define AML_UART_XMIT_IRQ(c) (((c) & 0xff) << 8)
76 #define AML_UART_RECV_IRQ(c) ((c) & 0xff)
78 /* AML_UART_REG5 bits */
79 #define AML_UART_BAUD_MASK 0x7fffff
80 #define AML_UART_BAUD_USE BIT(23)
81 #define AML_UART_BAUD_XTAL BIT(24)
83 #define AML_UART_PORT_NUM 6
84 #define AML_UART_DEV_NAME "ttyAML"
87 static struct uart_driver meson_uart_driver
;
89 static struct uart_port
*meson_ports
[AML_UART_PORT_NUM
];
91 static void meson_uart_set_mctrl(struct uart_port
*port
, unsigned int mctrl
)
95 static unsigned int meson_uart_get_mctrl(struct uart_port
*port
)
100 static unsigned int meson_uart_tx_empty(struct uart_port
*port
)
104 val
= readl(port
->membase
+ AML_UART_STATUS
);
105 val
&= (AML_UART_TX_EMPTY
| AML_UART_XMIT_BUSY
);
106 return (val
== AML_UART_TX_EMPTY
) ? TIOCSER_TEMT
: 0;
109 static void meson_uart_stop_tx(struct uart_port
*port
)
113 val
= readl(port
->membase
+ AML_UART_CONTROL
);
114 val
&= ~AML_UART_TX_INT_EN
;
115 writel(val
, port
->membase
+ AML_UART_CONTROL
);
118 static void meson_uart_stop_rx(struct uart_port
*port
)
122 val
= readl(port
->membase
+ AML_UART_CONTROL
);
123 val
&= ~AML_UART_RX_EN
;
124 writel(val
, port
->membase
+ AML_UART_CONTROL
);
127 static void meson_uart_shutdown(struct uart_port
*port
)
132 free_irq(port
->irq
, port
);
134 spin_lock_irqsave(&port
->lock
, flags
);
136 val
= readl(port
->membase
+ AML_UART_CONTROL
);
137 val
&= ~AML_UART_RX_EN
;
138 val
&= ~(AML_UART_RX_INT_EN
| AML_UART_TX_INT_EN
);
139 writel(val
, port
->membase
+ AML_UART_CONTROL
);
141 spin_unlock_irqrestore(&port
->lock
, flags
);
144 static void meson_uart_start_tx(struct uart_port
*port
)
146 struct circ_buf
*xmit
= &port
->state
->xmit
;
150 if (uart_tx_stopped(port
)) {
151 meson_uart_stop_tx(port
);
155 while (!(readl(port
->membase
+ AML_UART_STATUS
) & AML_UART_TX_FULL
)) {
157 writel(port
->x_char
, port
->membase
+ AML_UART_WFIFO
);
163 if (uart_circ_empty(xmit
))
166 ch
= xmit
->buf
[xmit
->tail
];
167 writel(ch
, port
->membase
+ AML_UART_WFIFO
);
168 xmit
->tail
= (xmit
->tail
+1) & (SERIAL_XMIT_SIZE
- 1);
172 if (!uart_circ_empty(xmit
)) {
173 val
= readl(port
->membase
+ AML_UART_CONTROL
);
174 val
|= AML_UART_TX_INT_EN
;
175 writel(val
, port
->membase
+ AML_UART_CONTROL
);
178 if (uart_circ_chars_pending(xmit
) < WAKEUP_CHARS
)
179 uart_write_wakeup(port
);
182 static void meson_receive_chars(struct uart_port
*port
)
184 struct tty_port
*tport
= &port
->state
->port
;
186 u32 status
, ch
, mode
;
191 status
= readl(port
->membase
+ AML_UART_STATUS
);
193 if (status
& AML_UART_ERR
) {
194 if (status
& AML_UART_TX_FIFO_WERR
)
195 port
->icount
.overrun
++;
196 else if (status
& AML_UART_FRAME_ERR
)
197 port
->icount
.frame
++;
198 else if (status
& AML_UART_PARITY_ERR
)
199 port
->icount
.frame
++;
201 mode
= readl(port
->membase
+ AML_UART_CONTROL
);
202 mode
|= AML_UART_CLEAR_ERR
;
203 writel(mode
, port
->membase
+ AML_UART_CONTROL
);
205 /* It doesn't clear to 0 automatically */
206 mode
&= ~AML_UART_CLEAR_ERR
;
207 writel(mode
, port
->membase
+ AML_UART_CONTROL
);
209 status
&= port
->read_status_mask
;
210 if (status
& AML_UART_FRAME_ERR
)
212 else if (status
& AML_UART_PARITY_ERR
)
216 ch
= readl(port
->membase
+ AML_UART_RFIFO
);
219 if ((status
& port
->ignore_status_mask
) == 0)
220 tty_insert_flip_char(tport
, ch
, flag
);
222 if (status
& AML_UART_TX_FIFO_WERR
)
223 tty_insert_flip_char(tport
, 0, TTY_OVERRUN
);
225 } while (!(readl(port
->membase
+ AML_UART_STATUS
) & AML_UART_RX_EMPTY
));
227 spin_unlock(&port
->lock
);
228 tty_flip_buffer_push(tport
);
229 spin_lock(&port
->lock
);
232 static irqreturn_t
meson_uart_interrupt(int irq
, void *dev_id
)
234 struct uart_port
*port
= (struct uart_port
*)dev_id
;
236 spin_lock(&port
->lock
);
238 if (!(readl(port
->membase
+ AML_UART_STATUS
) & AML_UART_RX_EMPTY
))
239 meson_receive_chars(port
);
241 if (!(readl(port
->membase
+ AML_UART_STATUS
) & AML_UART_TX_FULL
)) {
242 if (readl(port
->membase
+ AML_UART_CONTROL
) & AML_UART_TX_INT_EN
)
243 meson_uart_start_tx(port
);
246 spin_unlock(&port
->lock
);
251 static const char *meson_uart_type(struct uart_port
*port
)
253 return (port
->type
== PORT_MESON
) ? "meson_uart" : NULL
;
256 static void meson_uart_reset(struct uart_port
*port
)
260 val
= readl(port
->membase
+ AML_UART_CONTROL
);
261 val
|= (AML_UART_RX_RST
| AML_UART_TX_RST
| AML_UART_CLR_ERR
);
262 writel(val
, port
->membase
+ AML_UART_CONTROL
);
264 val
&= ~(AML_UART_RX_RST
| AML_UART_TX_RST
| AML_UART_CLR_ERR
);
265 writel(val
, port
->membase
+ AML_UART_CONTROL
);
268 static int meson_uart_startup(struct uart_port
*port
)
273 val
= readl(port
->membase
+ AML_UART_CONTROL
);
274 val
|= AML_UART_CLR_ERR
;
275 writel(val
, port
->membase
+ AML_UART_CONTROL
);
276 val
&= ~AML_UART_CLR_ERR
;
277 writel(val
, port
->membase
+ AML_UART_CONTROL
);
279 val
|= (AML_UART_RX_EN
| AML_UART_TX_EN
);
280 writel(val
, port
->membase
+ AML_UART_CONTROL
);
282 val
|= (AML_UART_RX_INT_EN
| AML_UART_TX_INT_EN
);
283 writel(val
, port
->membase
+ AML_UART_CONTROL
);
285 val
= (AML_UART_RECV_IRQ(1) | AML_UART_XMIT_IRQ(port
->fifosize
/ 2));
286 writel(val
, port
->membase
+ AML_UART_MISC
);
288 ret
= request_irq(port
->irq
, meson_uart_interrupt
, 0,
289 meson_uart_type(port
), port
);
294 static void meson_uart_change_speed(struct uart_port
*port
, unsigned long baud
)
298 while (!meson_uart_tx_empty(port
))
301 val
= readl(port
->membase
+ AML_UART_REG5
);
302 val
&= ~AML_UART_BAUD_MASK
;
303 if (port
->uartclk
== 24000000) {
304 val
= ((port
->uartclk
/ 3) / baud
) - 1;
305 val
|= AML_UART_BAUD_XTAL
;
307 val
= ((port
->uartclk
* 10 / (baud
* 4) + 5) / 10) - 1;
309 val
|= AML_UART_BAUD_USE
;
310 writel(val
, port
->membase
+ AML_UART_REG5
);
313 static void meson_uart_set_termios(struct uart_port
*port
,
314 struct ktermios
*termios
,
315 struct ktermios
*old
)
317 unsigned int cflags
, iflags
, baud
;
321 spin_lock_irqsave(&port
->lock
, flags
);
323 cflags
= termios
->c_cflag
;
324 iflags
= termios
->c_iflag
;
326 val
= readl(port
->membase
+ AML_UART_CONTROL
);
328 val
&= ~AML_UART_DATA_LEN_MASK
;
329 switch (cflags
& CSIZE
) {
331 val
|= AML_UART_DATA_LEN_8BIT
;
334 val
|= AML_UART_DATA_LEN_7BIT
;
337 val
|= AML_UART_DATA_LEN_6BIT
;
340 val
|= AML_UART_DATA_LEN_5BIT
;
345 val
|= AML_UART_PARITY_EN
;
347 val
&= ~AML_UART_PARITY_EN
;
350 val
|= AML_UART_PARITY_TYPE
;
352 val
&= ~AML_UART_PARITY_TYPE
;
354 val
&= ~AML_UART_STOP_BIN_LEN_MASK
;
356 val
|= AML_UART_STOP_BIN_2SB
;
358 val
&= ~AML_UART_STOP_BIN_1SB
;
360 if (cflags
& CRTSCTS
)
361 val
&= ~AML_UART_TWO_WIRE_EN
;
363 val
|= AML_UART_TWO_WIRE_EN
;
365 writel(val
, port
->membase
+ AML_UART_CONTROL
);
367 baud
= uart_get_baud_rate(port
, termios
, old
, 9600, 115200);
368 meson_uart_change_speed(port
, baud
);
370 port
->read_status_mask
= AML_UART_TX_FIFO_WERR
;
372 port
->read_status_mask
|= AML_UART_PARITY_ERR
|
375 port
->ignore_status_mask
= 0;
377 port
->ignore_status_mask
|= AML_UART_PARITY_ERR
|
380 uart_update_timeout(port
, termios
->c_cflag
, baud
);
381 spin_unlock_irqrestore(&port
->lock
, flags
);
384 static int meson_uart_verify_port(struct uart_port
*port
,
385 struct serial_struct
*ser
)
389 if (port
->type
!= PORT_MESON
)
391 if (port
->irq
!= ser
->irq
)
393 if (ser
->baud_base
< 9600)
398 static int meson_uart_res_size(struct uart_port
*port
)
400 struct platform_device
*pdev
= to_platform_device(port
->dev
);
401 struct resource
*res
;
403 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
405 dev_err(port
->dev
, "cannot obtain I/O memory region");
409 return resource_size(res
);
412 static void meson_uart_release_port(struct uart_port
*port
)
414 int size
= meson_uart_res_size(port
);
416 if (port
->flags
& UPF_IOREMAP
) {
417 devm_release_mem_region(port
->dev
, port
->mapbase
, size
);
418 devm_iounmap(port
->dev
, port
->membase
);
419 port
->membase
= NULL
;
423 static int meson_uart_request_port(struct uart_port
*port
)
425 int size
= meson_uart_res_size(port
);
430 if (!devm_request_mem_region(port
->dev
, port
->mapbase
, size
,
431 dev_name(port
->dev
))) {
432 dev_err(port
->dev
, "Memory region busy\n");
436 if (port
->flags
& UPF_IOREMAP
) {
437 port
->membase
= devm_ioremap_nocache(port
->dev
,
440 if (port
->membase
== NULL
)
447 static void meson_uart_config_port(struct uart_port
*port
, int flags
)
449 if (flags
& UART_CONFIG_TYPE
) {
450 port
->type
= PORT_MESON
;
451 meson_uart_request_port(port
);
455 static struct uart_ops meson_uart_ops
= {
456 .set_mctrl
= meson_uart_set_mctrl
,
457 .get_mctrl
= meson_uart_get_mctrl
,
458 .tx_empty
= meson_uart_tx_empty
,
459 .start_tx
= meson_uart_start_tx
,
460 .stop_tx
= meson_uart_stop_tx
,
461 .stop_rx
= meson_uart_stop_rx
,
462 .startup
= meson_uart_startup
,
463 .shutdown
= meson_uart_shutdown
,
464 .set_termios
= meson_uart_set_termios
,
465 .type
= meson_uart_type
,
466 .config_port
= meson_uart_config_port
,
467 .request_port
= meson_uart_request_port
,
468 .release_port
= meson_uart_release_port
,
469 .verify_port
= meson_uart_verify_port
,
472 #ifdef CONFIG_SERIAL_MESON_CONSOLE
474 static void meson_console_putchar(struct uart_port
*port
, int ch
)
479 while (readl(port
->membase
+ AML_UART_STATUS
) & AML_UART_TX_FULL
)
481 writel(ch
, port
->membase
+ AML_UART_WFIFO
);
484 static void meson_serial_port_write(struct uart_port
*port
, const char *s
,
491 local_irq_save(flags
);
494 } else if (oops_in_progress
) {
495 locked
= spin_trylock(&port
->lock
);
497 spin_lock(&port
->lock
);
501 val
= readl(port
->membase
+ AML_UART_CONTROL
);
502 val
|= AML_UART_TX_EN
;
503 tmp
= val
& ~(AML_UART_TX_INT_EN
| AML_UART_RX_INT_EN
);
504 writel(tmp
, port
->membase
+ AML_UART_CONTROL
);
506 uart_console_write(port
, s
, count
, meson_console_putchar
);
507 writel(val
, port
->membase
+ AML_UART_CONTROL
);
510 spin_unlock(&port
->lock
);
511 local_irq_restore(flags
);
514 static void meson_serial_console_write(struct console
*co
, const char *s
,
517 struct uart_port
*port
;
519 port
= meson_ports
[co
->index
];
523 meson_serial_port_write(port
, s
, count
);
526 static int meson_serial_console_setup(struct console
*co
, char *options
)
528 struct uart_port
*port
;
534 if (co
->index
< 0 || co
->index
>= AML_UART_PORT_NUM
)
537 port
= meson_ports
[co
->index
];
538 if (!port
|| !port
->membase
)
542 uart_parse_options(options
, &baud
, &parity
, &bits
, &flow
);
544 return uart_set_options(port
, co
, baud
, parity
, bits
, flow
);
547 static struct console meson_serial_console
= {
548 .name
= AML_UART_DEV_NAME
,
549 .write
= meson_serial_console_write
,
550 .device
= uart_console_device
,
551 .setup
= meson_serial_console_setup
,
552 .flags
= CON_PRINTBUFFER
,
554 .data
= &meson_uart_driver
,
557 static int __init
meson_serial_console_init(void)
559 register_console(&meson_serial_console
);
562 console_initcall(meson_serial_console_init
);
564 static void meson_serial_early_console_write(struct console
*co
,
568 struct earlycon_device
*dev
= co
->data
;
570 meson_serial_port_write(&dev
->port
, s
, count
);
574 meson_serial_early_console_setup(struct earlycon_device
*device
, const char *opt
)
576 if (!device
->port
.membase
)
579 device
->con
->write
= meson_serial_early_console_write
;
582 OF_EARLYCON_DECLARE(meson
, "amlogic,meson-uart",
583 meson_serial_early_console_setup
);
585 #define MESON_SERIAL_CONSOLE (&meson_serial_console)
587 #define MESON_SERIAL_CONSOLE NULL
590 static struct uart_driver meson_uart_driver
= {
591 .owner
= THIS_MODULE
,
592 .driver_name
= "meson_uart",
593 .dev_name
= AML_UART_DEV_NAME
,
594 .nr
= AML_UART_PORT_NUM
,
595 .cons
= MESON_SERIAL_CONSOLE
,
598 static int meson_uart_probe(struct platform_device
*pdev
)
600 struct resource
*res_mem
, *res_irq
;
601 struct uart_port
*port
;
605 if (pdev
->dev
.of_node
)
606 pdev
->id
= of_alias_get_id(pdev
->dev
.of_node
, "serial");
608 if (pdev
->id
< 0 || pdev
->id
>= AML_UART_PORT_NUM
)
611 res_mem
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
615 res_irq
= platform_get_resource(pdev
, IORESOURCE_IRQ
, 0);
619 if (meson_ports
[pdev
->id
]) {
620 dev_err(&pdev
->dev
, "port %d already allocated\n", pdev
->id
);
624 port
= devm_kzalloc(&pdev
->dev
, sizeof(struct uart_port
), GFP_KERNEL
);
628 clk
= clk_get(&pdev
->dev
, NULL
);
632 port
->uartclk
= clk_get_rate(clk
);
633 port
->iotype
= UPIO_MEM
;
634 port
->mapbase
= res_mem
->start
;
635 port
->irq
= res_irq
->start
;
636 port
->flags
= UPF_BOOT_AUTOCONF
| UPF_IOREMAP
| UPF_LOW_LATENCY
;
637 port
->dev
= &pdev
->dev
;
638 port
->line
= pdev
->id
;
639 port
->type
= PORT_MESON
;
641 port
->ops
= &meson_uart_ops
;
644 meson_ports
[pdev
->id
] = port
;
645 platform_set_drvdata(pdev
, port
);
647 /* reset port before registering (and possibly registering console) */
648 if (meson_uart_request_port(port
) >= 0) {
649 meson_uart_reset(port
);
650 meson_uart_release_port(port
);
653 ret
= uart_add_one_port(&meson_uart_driver
, port
);
655 meson_ports
[pdev
->id
] = NULL
;
660 static int meson_uart_remove(struct platform_device
*pdev
)
662 struct uart_port
*port
;
664 port
= platform_get_drvdata(pdev
);
665 uart_remove_one_port(&meson_uart_driver
, port
);
666 meson_ports
[pdev
->id
] = NULL
;
672 static const struct of_device_id meson_uart_dt_match
[] = {
673 { .compatible
= "amlogic,meson-uart" },
676 MODULE_DEVICE_TABLE(of
, meson_uart_dt_match
);
678 static struct platform_driver meson_uart_platform_driver
= {
679 .probe
= meson_uart_probe
,
680 .remove
= meson_uart_remove
,
682 .name
= "meson_uart",
683 .of_match_table
= meson_uart_dt_match
,
687 static int __init
meson_uart_init(void)
691 ret
= uart_register_driver(&meson_uart_driver
);
695 ret
= platform_driver_register(&meson_uart_platform_driver
);
697 uart_unregister_driver(&meson_uart_driver
);
702 static void __exit
meson_uart_exit(void)
704 platform_driver_unregister(&meson_uart_platform_driver
);
705 uart_unregister_driver(&meson_uart_driver
);
708 module_init(meson_uart_init
);
709 module_exit(meson_uart_exit
);
711 MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
712 MODULE_DESCRIPTION("Amlogic Meson serial port driver");
713 MODULE_LICENSE("GPL v2");