2 * Driver for Atmel AT91 / AT32 Serial ports
3 * Copyright (C) 2003 Rick Bronson
5 * Based on drivers/char/serial_sa1100.c, by Deep Blue Solutions Ltd.
6 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
8 * DMA support added by Chip Coldwell.
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 #include <linux/module.h>
26 #include <linux/tty.h>
27 #include <linux/ioport.h>
28 #include <linux/slab.h>
29 #include <linux/init.h>
30 #include <linux/serial.h>
31 #include <linux/clk.h>
32 #include <linux/console.h>
33 #include <linux/sysrq.h>
34 #include <linux/tty_flip.h>
35 #include <linux/platform_device.h>
37 #include <linux/of_device.h>
38 #include <linux/dma-mapping.h>
39 #include <linux/atmel_pdc.h>
40 #include <linux/atmel_serial.h>
41 #include <linux/uaccess.h>
42 #include <linux/pinctrl/consumer.h>
43 #include <linux/platform_data/atmel.h>
46 #include <asm/ioctls.h>
53 #define PDC_BUFFER_SIZE 512
54 /* Revisit: We should calculate this based on the actual port settings */
55 #define PDC_RX_TIMEOUT (3 * 10) /* 3 bytes */
57 #if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
61 #include <linux/serial_core.h>
63 static void atmel_start_rx(struct uart_port *port);
64 static void atmel_stop_rx(struct uart_port *port);
66 #ifdef CONFIG_SERIAL_ATMEL_TTYAT
68 /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we
69 * should coexist with the 8250 driver, such as if we have an external 16C550
71 #define SERIAL_ATMEL_MAJOR 204
72 #define MINOR_START 154
73 #define ATMEL_DEVICENAME "ttyAT"
77 /* Use device name ttyS, major 4, minor 64-68. This is the usual serial port
78 * name, but it is legally reserved for the 8250 driver. */
79 #define SERIAL_ATMEL_MAJOR TTY_MAJOR
80 #define MINOR_START 64
81 #define ATMEL_DEVICENAME "ttyS"
85 #define ATMEL_ISR_PASS_LIMIT 256
87 /* UART registers. CR is write-only, hence no GET macro */
88 #define UART_PUT_CR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_CR)
89 #define UART_GET_MR(port) __raw_readl((port)->membase + ATMEL_US_MR)
90 #define UART_PUT_MR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_MR)
91 #define UART_PUT_IER(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IER)
92 #define UART_PUT_IDR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IDR)
93 #define UART_GET_IMR(port) __raw_readl((port)->membase + ATMEL_US_IMR)
94 #define UART_GET_CSR(port) __raw_readl((port)->membase + ATMEL_US_CSR)
95 #define UART_GET_CHAR(port) __raw_readl((port)->membase + ATMEL_US_RHR)
96 #define UART_PUT_CHAR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_THR)
97 #define UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR)
98 #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_BRGR)
99 #define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_RTOR)
100 #define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase + ATMEL_US_TTGR)
103 #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR)
104 #define UART_GET_PTSR(port) __raw_readl((port)->membase + ATMEL_PDC_PTSR)
106 #define UART_PUT_RPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RPR)
107 #define UART_GET_RPR(port) __raw_readl((port)->membase + ATMEL_PDC_RPR)
108 #define UART_PUT_RCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RCR)
109 #define UART_PUT_RNPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNPR)
110 #define UART_PUT_RNCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNCR)
112 #define UART_PUT_TPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TPR)
113 #define UART_PUT_TCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TCR)
114 #define UART_GET_TCR(port) __raw_readl((port)->membase + ATMEL_PDC_TCR)
116 static int (*atmel_open_hook)(struct uart_port *);
117 static void (*atmel_close_hook)(struct uart_port *);
119 struct atmel_dma_buffer {
122 unsigned int dma_size;
126 struct atmel_uart_char {
131 #define ATMEL_SERIAL_RINGSIZE 1024
134 * We wrap our port structure around the generic uart_port.
136 struct atmel_uart_port {
137 struct uart_port uart; /* uart */
138 struct clk *clk; /* uart clock */
139 int may_wakeup; /* cached value of device_may_wakeup for times we need to disable it */
140 u32 backup_imr; /* IMR saved during suspend */
141 int break_active; /* break being received */
143 short use_dma_rx; /* enable PDC receiver */
144 short pdc_rx_idx; /* current PDC RX buffer */
145 struct atmel_dma_buffer pdc_rx[2]; /* PDC receier */
147 short use_dma_tx; /* enable PDC transmitter */
148 struct atmel_dma_buffer pdc_tx; /* PDC transmitter */
150 struct tasklet_struct tasklet;
151 unsigned int irq_status;
152 unsigned int irq_status_prev;
154 struct circ_buf rx_ring;
156 struct serial_rs485 rs485; /* rs485 settings */
157 unsigned int tx_done_mask;
160 static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
161 static unsigned long atmel_ports_in_use;
164 static struct console atmel_console;
167 #if defined(CONFIG_OF)
168 static const struct of_device_id atmel_serial_dt_ids[] = {
169 { .compatible = "atmel,at91rm9200-usart" },
170 { .compatible = "atmel,at91sam9260-usart" },
174 MODULE_DEVICE_TABLE(of, atmel_serial_dt_ids);
177 static inline struct atmel_uart_port *
178 to_atmel_uart_port(struct uart_port *uart)
180 return container_of(uart, struct atmel_uart_port, uart);
183 #ifdef CONFIG_SERIAL_ATMEL_PDC
184 static bool atmel_use_dma_rx(struct uart_port *port)
186 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
188 return atmel_port->use_dma_rx;
191 static bool atmel_use_dma_tx(struct uart_port *port)
193 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
195 return atmel_port->use_dma_tx;
198 static bool atmel_use_dma_rx(struct uart_port *port)
203 static bool atmel_use_dma_tx(struct uart_port *port)
209 /* Enable or disable the rs485 support */
210 void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
212 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
216 spin_lock_irqsave(&port->lock, flags);
218 /* Disable interrupts */
219 UART_PUT_IDR(port, atmel_port->tx_done_mask);
221 mode = UART_GET_MR(port);
223 /* Resetting serial mode to RS232 (0x0) */
224 mode &= ~ATMEL_US_USMODE;
226 atmel_port->rs485 = *rs485conf;
228 if (rs485conf->flags & SER_RS485_ENABLED) {
229 dev_dbg(port->dev, "Setting UART to RS485\n");
230 atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
231 if ((rs485conf->delay_rts_after_send) > 0)
232 UART_PUT_TTGR(port, rs485conf->delay_rts_after_send);
233 mode |= ATMEL_US_USMODE_RS485;
235 dev_dbg(port->dev, "Setting UART to RS232\n");
236 if (atmel_use_dma_tx(port))
237 atmel_port->tx_done_mask = ATMEL_US_ENDTX |
240 atmel_port->tx_done_mask = ATMEL_US_TXRDY;
242 UART_PUT_MR(port, mode);
244 /* Enable interrupts */
245 UART_PUT_IER(port, atmel_port->tx_done_mask);
247 spin_unlock_irqrestore(&port->lock, flags);
252 * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
254 static u_int atmel_tx_empty(struct uart_port *port)
256 return (UART_GET_CSR(port) & ATMEL_US_TXEMPTY) ? TIOCSER_TEMT : 0;
260 * Set state of the modem control output lines
262 static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
264 unsigned int control = 0;
266 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
268 #ifdef CONFIG_ARCH_AT91RM9200
269 if (cpu_is_at91rm9200()) {
271 * AT91RM9200 Errata #39: RTS0 is not internally connected
272 * to PA21. We need to drive the pin manually.
274 if (port->mapbase == AT91RM9200_BASE_US0) {
275 if (mctrl & TIOCM_RTS)
276 at91_set_gpio_value(AT91_PIN_PA21, 0);
278 at91_set_gpio_value(AT91_PIN_PA21, 1);
283 if (mctrl & TIOCM_RTS)
284 control |= ATMEL_US_RTSEN;
286 control |= ATMEL_US_RTSDIS;
288 if (mctrl & TIOCM_DTR)
289 control |= ATMEL_US_DTREN;
291 control |= ATMEL_US_DTRDIS;
293 UART_PUT_CR(port, control);
295 /* Local loopback mode? */
296 mode = UART_GET_MR(port) & ~ATMEL_US_CHMODE;
297 if (mctrl & TIOCM_LOOP)
298 mode |= ATMEL_US_CHMODE_LOC_LOOP;
300 mode |= ATMEL_US_CHMODE_NORMAL;
302 /* Resetting serial mode to RS232 (0x0) */
303 mode &= ~ATMEL_US_USMODE;
305 if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
306 dev_dbg(port->dev, "Setting UART to RS485\n");
307 if ((atmel_port->rs485.delay_rts_after_send) > 0)
309 atmel_port->rs485.delay_rts_after_send);
310 mode |= ATMEL_US_USMODE_RS485;
312 dev_dbg(port->dev, "Setting UART to RS232\n");
314 UART_PUT_MR(port, mode);
318 * Get state of the modem control input lines
320 static u_int atmel_get_mctrl(struct uart_port *port)
322 unsigned int status, ret = 0;
324 status = UART_GET_CSR(port);
327 * The control signals are active low.
329 if (!(status & ATMEL_US_DCD))
331 if (!(status & ATMEL_US_CTS))
333 if (!(status & ATMEL_US_DSR))
335 if (!(status & ATMEL_US_RI))
344 static void atmel_stop_tx(struct uart_port *port)
346 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
348 if (atmel_use_dma_tx(port)) {
349 /* disable PDC transmit */
350 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
352 /* Disable interrupts */
353 UART_PUT_IDR(port, atmel_port->tx_done_mask);
355 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
356 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
357 atmel_start_rx(port);
361 * Start transmitting.
363 static void atmel_start_tx(struct uart_port *port)
365 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
367 if (atmel_use_dma_tx(port)) {
368 if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN)
369 /* The transmitter is already running. Yes, we
373 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
374 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
377 /* re-enable PDC transmit */
378 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
380 /* Enable interrupts */
381 UART_PUT_IER(port, atmel_port->tx_done_mask);
385 * start receiving - port is in process of being opened.
387 static void atmel_start_rx(struct uart_port *port)
389 UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */
391 UART_PUT_CR(port, ATMEL_US_RXEN);
393 if (atmel_use_dma_rx(port)) {
394 /* enable PDC controller */
395 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
396 port->read_status_mask);
397 UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
399 UART_PUT_IER(port, ATMEL_US_RXRDY);
404 * Stop receiving - port is in process of being closed.
406 static void atmel_stop_rx(struct uart_port *port)
408 UART_PUT_CR(port, ATMEL_US_RXDIS);
410 if (atmel_use_dma_rx(port)) {
411 /* disable PDC receive */
412 UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS);
413 UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
414 port->read_status_mask);
416 UART_PUT_IDR(port, ATMEL_US_RXRDY);
421 * Enable modem status interrupts
423 static void atmel_enable_ms(struct uart_port *port)
425 UART_PUT_IER(port, ATMEL_US_RIIC | ATMEL_US_DSRIC
426 | ATMEL_US_DCDIC | ATMEL_US_CTSIC);
430 * Control the transmission of a break signal
432 static void atmel_break_ctl(struct uart_port *port, int break_state)
434 if (break_state != 0)
435 UART_PUT_CR(port, ATMEL_US_STTBRK); /* start break */
437 UART_PUT_CR(port, ATMEL_US_STPBRK); /* stop break */
441 * Stores the incoming character in the ring buffer
444 atmel_buffer_rx_char(struct uart_port *port, unsigned int status,
447 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
448 struct circ_buf *ring = &atmel_port->rx_ring;
449 struct atmel_uart_char *c;
451 if (!CIRC_SPACE(ring->head, ring->tail, ATMEL_SERIAL_RINGSIZE))
452 /* Buffer overflow, ignore char */
455 c = &((struct atmel_uart_char *)ring->buf)[ring->head];
459 /* Make sure the character is stored before we update head. */
462 ring->head = (ring->head + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
466 * Deal with parity, framing and overrun errors.
468 static void atmel_pdc_rxerr(struct uart_port *port, unsigned int status)
471 UART_PUT_CR(port, ATMEL_US_RSTSTA);
473 if (status & ATMEL_US_RXBRK) {
474 /* ignore side-effect */
475 status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
478 if (status & ATMEL_US_PARE)
479 port->icount.parity++;
480 if (status & ATMEL_US_FRAME)
481 port->icount.frame++;
482 if (status & ATMEL_US_OVRE)
483 port->icount.overrun++;
487 * Characters received (called from interrupt handler)
489 static void atmel_rx_chars(struct uart_port *port)
491 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
492 unsigned int status, ch;
494 status = UART_GET_CSR(port);
495 while (status & ATMEL_US_RXRDY) {
496 ch = UART_GET_CHAR(port);
499 * note that the error handling code is
500 * out of the main execution path
502 if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
503 | ATMEL_US_OVRE | ATMEL_US_RXBRK)
504 || atmel_port->break_active)) {
507 UART_PUT_CR(port, ATMEL_US_RSTSTA);
509 if (status & ATMEL_US_RXBRK
510 && !atmel_port->break_active) {
511 atmel_port->break_active = 1;
512 UART_PUT_IER(port, ATMEL_US_RXBRK);
515 * This is either the end-of-break
516 * condition or we've received at
517 * least one character without RXBRK
518 * being set. In both cases, the next
519 * RXBRK will indicate start-of-break.
521 UART_PUT_IDR(port, ATMEL_US_RXBRK);
522 status &= ~ATMEL_US_RXBRK;
523 atmel_port->break_active = 0;
527 atmel_buffer_rx_char(port, status, ch);
528 status = UART_GET_CSR(port);
531 tasklet_schedule(&atmel_port->tasklet);
535 * Transmit characters (called from tasklet with TXRDY interrupt
538 static void atmel_tx_chars(struct uart_port *port)
540 struct circ_buf *xmit = &port->state->xmit;
541 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
543 if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) {
544 UART_PUT_CHAR(port, port->x_char);
548 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
551 while (UART_GET_CSR(port) & atmel_port->tx_done_mask) {
552 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
553 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
555 if (uart_circ_empty(xmit))
559 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
560 uart_write_wakeup(port);
562 if (!uart_circ_empty(xmit))
563 /* Enable interrupts */
564 UART_PUT_IER(port, atmel_port->tx_done_mask);
568 * receive interrupt handler.
571 atmel_handle_receive(struct uart_port *port, unsigned int pending)
573 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
575 if (atmel_use_dma_rx(port)) {
577 * PDC receive. Just schedule the tasklet and let it
578 * figure out the details.
580 * TODO: We're not handling error flags correctly at
583 if (pending & (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)) {
584 UART_PUT_IDR(port, (ATMEL_US_ENDRX
585 | ATMEL_US_TIMEOUT));
586 tasklet_schedule(&atmel_port->tasklet);
589 if (pending & (ATMEL_US_RXBRK | ATMEL_US_OVRE |
590 ATMEL_US_FRAME | ATMEL_US_PARE))
591 atmel_pdc_rxerr(port, pending);
594 /* Interrupt receive */
595 if (pending & ATMEL_US_RXRDY)
596 atmel_rx_chars(port);
597 else if (pending & ATMEL_US_RXBRK) {
599 * End of break detected. If it came along with a
600 * character, atmel_rx_chars will handle it.
602 UART_PUT_CR(port, ATMEL_US_RSTSTA);
603 UART_PUT_IDR(port, ATMEL_US_RXBRK);
604 atmel_port->break_active = 0;
609 * transmit interrupt handler. (Transmit is IRQF_NODELAY safe)
612 atmel_handle_transmit(struct uart_port *port, unsigned int pending)
614 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
616 if (pending & atmel_port->tx_done_mask) {
617 /* Either PDC or interrupt transmission */
618 UART_PUT_IDR(port, atmel_port->tx_done_mask);
619 tasklet_schedule(&atmel_port->tasklet);
624 * status flags interrupt handler.
627 atmel_handle_status(struct uart_port *port, unsigned int pending,
630 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
632 if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC
634 atmel_port->irq_status = status;
635 tasklet_schedule(&atmel_port->tasklet);
642 static irqreturn_t atmel_interrupt(int irq, void *dev_id)
644 struct uart_port *port = dev_id;
645 unsigned int status, pending, pass_counter = 0;
648 status = UART_GET_CSR(port);
649 pending = status & UART_GET_IMR(port);
653 atmel_handle_receive(port, pending);
654 atmel_handle_status(port, pending, status);
655 atmel_handle_transmit(port, pending);
656 } while (pass_counter++ < ATMEL_ISR_PASS_LIMIT);
658 return pass_counter ? IRQ_HANDLED : IRQ_NONE;
662 * Called from tasklet with ENDTX and TXBUFE interrupts disabled.
664 static void atmel_tx_dma(struct uart_port *port)
666 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
667 struct circ_buf *xmit = &port->state->xmit;
668 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
671 /* nothing left to transmit? */
672 if (UART_GET_TCR(port))
675 xmit->tail += pdc->ofs;
676 xmit->tail &= UART_XMIT_SIZE - 1;
678 port->icount.tx += pdc->ofs;
681 /* more to transmit - setup next transfer */
683 /* disable PDC transmit */
684 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
686 if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
687 dma_sync_single_for_device(port->dev,
692 count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
695 UART_PUT_TPR(port, pdc->dma_addr + xmit->tail);
696 UART_PUT_TCR(port, count);
697 /* re-enable PDC transmit */
698 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
699 /* Enable interrupts */
700 UART_PUT_IER(port, atmel_port->tx_done_mask);
702 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
703 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX)) {
704 /* DMA done, stop TX, start RX for RS485 */
705 atmel_start_rx(port);
709 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
710 uart_write_wakeup(port);
713 static void atmel_rx_from_ring(struct uart_port *port)
715 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
716 struct circ_buf *ring = &atmel_port->rx_ring;
720 while (ring->head != ring->tail) {
721 struct atmel_uart_char c;
723 /* Make sure c is loaded after head. */
726 c = ((struct atmel_uart_char *)ring->buf)[ring->tail];
728 ring->tail = (ring->tail + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
735 * note that the error handling code is
736 * out of the main execution path
738 if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
739 | ATMEL_US_OVRE | ATMEL_US_RXBRK))) {
740 if (status & ATMEL_US_RXBRK) {
741 /* ignore side-effect */
742 status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
745 if (uart_handle_break(port))
748 if (status & ATMEL_US_PARE)
749 port->icount.parity++;
750 if (status & ATMEL_US_FRAME)
751 port->icount.frame++;
752 if (status & ATMEL_US_OVRE)
753 port->icount.overrun++;
755 status &= port->read_status_mask;
757 if (status & ATMEL_US_RXBRK)
759 else if (status & ATMEL_US_PARE)
761 else if (status & ATMEL_US_FRAME)
766 if (uart_handle_sysrq_char(port, c.ch))
769 uart_insert_char(port, status, ATMEL_US_OVRE, c.ch, flg);
773 * Drop the lock here since it might end up calling
774 * uart_start(), which takes the lock.
776 spin_unlock(&port->lock);
777 tty_flip_buffer_push(&port->state->port);
778 spin_lock(&port->lock);
781 static void atmel_rx_from_dma(struct uart_port *port)
783 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
784 struct tty_port *tport = &port->state->port;
785 struct atmel_dma_buffer *pdc;
786 int rx_idx = atmel_port->pdc_rx_idx;
792 /* Reset the UART timeout early so that we don't miss one */
793 UART_PUT_CR(port, ATMEL_US_STTTO);
795 pdc = &atmel_port->pdc_rx[rx_idx];
796 head = UART_GET_RPR(port) - pdc->dma_addr;
799 /* If the PDC has switched buffers, RPR won't contain
800 * any address within the current buffer. Since head
801 * is unsigned, we just need a one-way comparison to
804 * In this case, we just need to consume the entire
805 * buffer and resubmit it for DMA. This will clear the
806 * ENDRX bit as well, so that we can safely re-enable
807 * all interrupts below.
809 head = min(head, pdc->dma_size);
811 if (likely(head != tail)) {
812 dma_sync_single_for_cpu(port->dev, pdc->dma_addr,
813 pdc->dma_size, DMA_FROM_DEVICE);
816 * head will only wrap around when we recycle
817 * the DMA buffer, and when that happens, we
818 * explicitly set tail to 0. So head will
819 * always be greater than tail.
823 tty_insert_flip_string(tport, pdc->buf + pdc->ofs,
826 dma_sync_single_for_device(port->dev, pdc->dma_addr,
827 pdc->dma_size, DMA_FROM_DEVICE);
829 port->icount.rx += count;
834 * If the current buffer is full, we need to check if
835 * the next one contains any additional data.
837 if (head >= pdc->dma_size) {
839 UART_PUT_RNPR(port, pdc->dma_addr);
840 UART_PUT_RNCR(port, pdc->dma_size);
843 atmel_port->pdc_rx_idx = rx_idx;
845 } while (head >= pdc->dma_size);
848 * Drop the lock here since it might end up calling
849 * uart_start(), which takes the lock.
851 spin_unlock(&port->lock);
852 tty_flip_buffer_push(tport);
853 spin_lock(&port->lock);
855 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
859 * tasklet handling tty stuff outside the interrupt handler.
861 static void atmel_tasklet_func(unsigned long data)
863 struct uart_port *port = (struct uart_port *)data;
864 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
866 unsigned int status_change;
868 /* The interrupt handler does not take the lock */
869 spin_lock(&port->lock);
871 if (atmel_use_dma_tx(port))
874 atmel_tx_chars(port);
876 status = atmel_port->irq_status;
877 status_change = status ^ atmel_port->irq_status_prev;
879 if (status_change & (ATMEL_US_RI | ATMEL_US_DSR
880 | ATMEL_US_DCD | ATMEL_US_CTS)) {
881 /* TODO: All reads to CSR will clear these interrupts! */
882 if (status_change & ATMEL_US_RI)
884 if (status_change & ATMEL_US_DSR)
886 if (status_change & ATMEL_US_DCD)
887 uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
888 if (status_change & ATMEL_US_CTS)
889 uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
891 wake_up_interruptible(&port->state->port.delta_msr_wait);
893 atmel_port->irq_status_prev = status;
896 if (atmel_use_dma_rx(port))
897 atmel_rx_from_dma(port);
899 atmel_rx_from_ring(port);
901 spin_unlock(&port->lock);
905 * Perform initialization and enable port for reception
907 static int atmel_startup(struct uart_port *port)
909 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
910 struct tty_struct *tty = port->state->port.tty;
914 * Ensure that no interrupts are enabled otherwise when
915 * request_irq() is called we could get stuck trying to
916 * handle an unexpected interrupt
918 UART_PUT_IDR(port, -1);
923 retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED,
924 tty ? tty->name : "atmel_serial", port);
926 printk("atmel_serial: atmel_startup - Can't get irq\n");
931 * Initialize DMA (if necessary)
933 if (atmel_use_dma_rx(port)) {
936 for (i = 0; i < 2; i++) {
937 struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
939 pdc->buf = kmalloc(PDC_BUFFER_SIZE, GFP_KERNEL);
940 if (pdc->buf == NULL) {
942 dma_unmap_single(port->dev,
943 atmel_port->pdc_rx[0].dma_addr,
946 kfree(atmel_port->pdc_rx[0].buf);
948 free_irq(port->irq, port);
951 pdc->dma_addr = dma_map_single(port->dev,
955 pdc->dma_size = PDC_BUFFER_SIZE;
959 atmel_port->pdc_rx_idx = 0;
961 UART_PUT_RPR(port, atmel_port->pdc_rx[0].dma_addr);
962 UART_PUT_RCR(port, PDC_BUFFER_SIZE);
964 UART_PUT_RNPR(port, atmel_port->pdc_rx[1].dma_addr);
965 UART_PUT_RNCR(port, PDC_BUFFER_SIZE);
967 if (atmel_use_dma_tx(port)) {
968 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
969 struct circ_buf *xmit = &port->state->xmit;
971 pdc->buf = xmit->buf;
972 pdc->dma_addr = dma_map_single(port->dev,
976 pdc->dma_size = UART_XMIT_SIZE;
981 * If there is a specific "open" function (to register
982 * control line interrupts)
984 if (atmel_open_hook) {
985 retval = atmel_open_hook(port);
987 free_irq(port->irq, port);
992 /* Save current CSR for comparison in atmel_tasklet_func() */
993 atmel_port->irq_status_prev = UART_GET_CSR(port);
994 atmel_port->irq_status = atmel_port->irq_status_prev;
997 * Finally, enable the serial port
999 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1000 /* enable xmit & rcvr */
1001 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1003 if (atmel_use_dma_rx(port)) {
1004 /* set UART timeout */
1005 UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
1006 UART_PUT_CR(port, ATMEL_US_STTTO);
1008 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
1009 /* enable PDC controller */
1010 UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
1012 /* enable receive only */
1013 UART_PUT_IER(port, ATMEL_US_RXRDY);
1022 static void atmel_shutdown(struct uart_port *port)
1024 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1026 * Ensure everything is stopped.
1028 atmel_stop_rx(port);
1029 atmel_stop_tx(port);
1032 * Shut-down the DMA.
1034 if (atmel_use_dma_rx(port)) {
1037 for (i = 0; i < 2; i++) {
1038 struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
1040 dma_unmap_single(port->dev,
1047 if (atmel_use_dma_tx(port)) {
1048 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
1050 dma_unmap_single(port->dev,
1057 * Disable all interrupts, port and break condition.
1059 UART_PUT_CR(port, ATMEL_US_RSTSTA);
1060 UART_PUT_IDR(port, -1);
1063 * Free the interrupt
1065 free_irq(port->irq, port);
1068 * If there is a specific "close" function (to unregister
1069 * control line interrupts)
1071 if (atmel_close_hook)
1072 atmel_close_hook(port);
1076 * Flush any TX data submitted for DMA. Called when the TX circular
1079 static void atmel_flush_buffer(struct uart_port *port)
1081 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1083 if (atmel_use_dma_tx(port)) {
1084 UART_PUT_TCR(port, 0);
1085 atmel_port->pdc_tx.ofs = 0;
1090 * Power / Clock management.
1092 static void atmel_serial_pm(struct uart_port *port, unsigned int state,
1093 unsigned int oldstate)
1095 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1100 * Enable the peripheral clock for this serial port.
1101 * This is called on uart_open() or a resume event.
1103 clk_enable(atmel_port->clk);
1105 /* re-enable interrupts if we disabled some on suspend */
1106 UART_PUT_IER(port, atmel_port->backup_imr);
1109 /* Back up the interrupt mask and disable all interrupts */
1110 atmel_port->backup_imr = UART_GET_IMR(port);
1111 UART_PUT_IDR(port, -1);
1114 * Disable the peripheral clock for this serial port.
1115 * This is called on uart_close() or a suspend event.
1117 clk_disable(atmel_port->clk);
1120 printk(KERN_ERR "atmel_serial: unknown pm %d\n", state);
1125 * Change the port parameters
1127 static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
1128 struct ktermios *old)
1130 unsigned long flags;
1131 unsigned int mode, imr, quot, baud;
1132 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1134 /* Get current mode register */
1135 mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL
1136 | ATMEL_US_NBSTOP | ATMEL_US_PAR
1139 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
1140 quot = uart_get_divisor(port, baud);
1142 if (quot > 65535) { /* BRGR is 16-bit, so switch to slower clock */
1144 mode |= ATMEL_US_USCLKS_MCK_DIV8;
1148 switch (termios->c_cflag & CSIZE) {
1150 mode |= ATMEL_US_CHRL_5;
1153 mode |= ATMEL_US_CHRL_6;
1156 mode |= ATMEL_US_CHRL_7;
1159 mode |= ATMEL_US_CHRL_8;
1164 if (termios->c_cflag & CSTOPB)
1165 mode |= ATMEL_US_NBSTOP_2;
1168 if (termios->c_cflag & PARENB) {
1169 /* Mark or Space parity */
1170 if (termios->c_cflag & CMSPAR) {
1171 if (termios->c_cflag & PARODD)
1172 mode |= ATMEL_US_PAR_MARK;
1174 mode |= ATMEL_US_PAR_SPACE;
1175 } else if (termios->c_cflag & PARODD)
1176 mode |= ATMEL_US_PAR_ODD;
1178 mode |= ATMEL_US_PAR_EVEN;
1180 mode |= ATMEL_US_PAR_NONE;
1182 /* hardware handshake (RTS/CTS) */
1183 if (termios->c_cflag & CRTSCTS)
1184 mode |= ATMEL_US_USMODE_HWHS;
1186 mode |= ATMEL_US_USMODE_NORMAL;
1188 spin_lock_irqsave(&port->lock, flags);
1190 port->read_status_mask = ATMEL_US_OVRE;
1191 if (termios->c_iflag & INPCK)
1192 port->read_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
1193 if (termios->c_iflag & (BRKINT | PARMRK))
1194 port->read_status_mask |= ATMEL_US_RXBRK;
1196 if (atmel_use_dma_rx(port))
1197 /* need to enable error interrupts */
1198 UART_PUT_IER(port, port->read_status_mask);
1201 * Characters to ignore
1203 port->ignore_status_mask = 0;
1204 if (termios->c_iflag & IGNPAR)
1205 port->ignore_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
1206 if (termios->c_iflag & IGNBRK) {
1207 port->ignore_status_mask |= ATMEL_US_RXBRK;
1209 * If we're ignoring parity and break indicators,
1210 * ignore overruns too (for real raw support).
1212 if (termios->c_iflag & IGNPAR)
1213 port->ignore_status_mask |= ATMEL_US_OVRE;
1215 /* TODO: Ignore all characters if CREAD is set.*/
1217 /* update the per-port timeout */
1218 uart_update_timeout(port, termios->c_cflag, baud);
1221 * save/disable interrupts. The tty layer will ensure that the
1222 * transmitter is empty if requested by the caller, so there's
1223 * no need to wait for it here.
1225 imr = UART_GET_IMR(port);
1226 UART_PUT_IDR(port, -1);
1228 /* disable receiver and transmitter */
1229 UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
1231 /* Resetting serial mode to RS232 (0x0) */
1232 mode &= ~ATMEL_US_USMODE;
1234 if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
1235 dev_dbg(port->dev, "Setting UART to RS485\n");
1236 if ((atmel_port->rs485.delay_rts_after_send) > 0)
1238 atmel_port->rs485.delay_rts_after_send);
1239 mode |= ATMEL_US_USMODE_RS485;
1241 dev_dbg(port->dev, "Setting UART to RS232\n");
1244 /* set the parity, stop bits and data size */
1245 UART_PUT_MR(port, mode);
1247 /* set the baud rate */
1248 UART_PUT_BRGR(port, quot);
1249 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1250 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1252 /* restore interrupts */
1253 UART_PUT_IER(port, imr);
1255 /* CTS flow-control and modem-status interrupts */
1256 if (UART_ENABLE_MS(port, termios->c_cflag))
1257 port->ops->enable_ms(port);
1259 spin_unlock_irqrestore(&port->lock, flags);
1262 static void atmel_set_ldisc(struct uart_port *port, int new)
1265 port->flags |= UPF_HARDPPS_CD;
1266 atmel_enable_ms(port);
1268 port->flags &= ~UPF_HARDPPS_CD;
1273 * Return string describing the specified port
1275 static const char *atmel_type(struct uart_port *port)
1277 return (port->type == PORT_ATMEL) ? "ATMEL_SERIAL" : NULL;
1281 * Release the memory region(s) being used by 'port'.
1283 static void atmel_release_port(struct uart_port *port)
1285 struct platform_device *pdev = to_platform_device(port->dev);
1286 int size = pdev->resource[0].end - pdev->resource[0].start + 1;
1288 release_mem_region(port->mapbase, size);
1290 if (port->flags & UPF_IOREMAP) {
1291 iounmap(port->membase);
1292 port->membase = NULL;
1297 * Request the memory region(s) being used by 'port'.
1299 static int atmel_request_port(struct uart_port *port)
1301 struct platform_device *pdev = to_platform_device(port->dev);
1302 int size = pdev->resource[0].end - pdev->resource[0].start + 1;
1304 if (!request_mem_region(port->mapbase, size, "atmel_serial"))
1307 if (port->flags & UPF_IOREMAP) {
1308 port->membase = ioremap(port->mapbase, size);
1309 if (port->membase == NULL) {
1310 release_mem_region(port->mapbase, size);
1319 * Configure/autoconfigure the port.
1321 static void atmel_config_port(struct uart_port *port, int flags)
1323 if (flags & UART_CONFIG_TYPE) {
1324 port->type = PORT_ATMEL;
1325 atmel_request_port(port);
1330 * Verify the new serial_struct (for TIOCSSERIAL).
1332 static int atmel_verify_port(struct uart_port *port, struct serial_struct *ser)
1335 if (ser->type != PORT_UNKNOWN && ser->type != PORT_ATMEL)
1337 if (port->irq != ser->irq)
1339 if (ser->io_type != SERIAL_IO_MEM)
1341 if (port->uartclk / 16 != ser->baud_base)
1343 if ((void *)port->mapbase != ser->iomem_base)
1345 if (port->iobase != ser->port)
1352 #ifdef CONFIG_CONSOLE_POLL
1353 static int atmel_poll_get_char(struct uart_port *port)
1355 while (!(UART_GET_CSR(port) & ATMEL_US_RXRDY))
1358 return UART_GET_CHAR(port);
1361 static void atmel_poll_put_char(struct uart_port *port, unsigned char ch)
1363 while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
1366 UART_PUT_CHAR(port, ch);
1371 atmel_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg)
1373 struct serial_rs485 rs485conf;
1377 if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg,
1381 atmel_config_rs485(port, &rs485conf);
1385 if (copy_to_user((struct serial_rs485 *) arg,
1386 &(to_atmel_uart_port(port)->rs485),
1392 return -ENOIOCTLCMD;
1399 static struct uart_ops atmel_pops = {
1400 .tx_empty = atmel_tx_empty,
1401 .set_mctrl = atmel_set_mctrl,
1402 .get_mctrl = atmel_get_mctrl,
1403 .stop_tx = atmel_stop_tx,
1404 .start_tx = atmel_start_tx,
1405 .stop_rx = atmel_stop_rx,
1406 .enable_ms = atmel_enable_ms,
1407 .break_ctl = atmel_break_ctl,
1408 .startup = atmel_startup,
1409 .shutdown = atmel_shutdown,
1410 .flush_buffer = atmel_flush_buffer,
1411 .set_termios = atmel_set_termios,
1412 .set_ldisc = atmel_set_ldisc,
1414 .release_port = atmel_release_port,
1415 .request_port = atmel_request_port,
1416 .config_port = atmel_config_port,
1417 .verify_port = atmel_verify_port,
1418 .pm = atmel_serial_pm,
1419 .ioctl = atmel_ioctl,
1420 #ifdef CONFIG_CONSOLE_POLL
1421 .poll_get_char = atmel_poll_get_char,
1422 .poll_put_char = atmel_poll_put_char,
1426 static void atmel_of_init_port(struct atmel_uart_port *atmel_port,
1427 struct device_node *np)
1431 /* DMA/PDC usage specification */
1432 if (of_get_property(np, "atmel,use-dma-rx", NULL))
1433 atmel_port->use_dma_rx = 1;
1435 atmel_port->use_dma_rx = 0;
1436 if (of_get_property(np, "atmel,use-dma-tx", NULL))
1437 atmel_port->use_dma_tx = 1;
1439 atmel_port->use_dma_tx = 0;
1441 /* rs485 properties */
1442 if (of_property_read_u32_array(np, "rs485-rts-delay",
1443 rs485_delay, 2) == 0) {
1444 struct serial_rs485 *rs485conf = &atmel_port->rs485;
1446 rs485conf->delay_rts_before_send = rs485_delay[0];
1447 rs485conf->delay_rts_after_send = rs485_delay[1];
1448 rs485conf->flags = 0;
1450 if (of_get_property(np, "rs485-rx-during-tx", NULL))
1451 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1453 if (of_get_property(np, "linux,rs485-enabled-at-boot-time", NULL))
1454 rs485conf->flags |= SER_RS485_ENABLED;
1459 * Configure the port from the platform device resource info.
1461 static void atmel_init_port(struct atmel_uart_port *atmel_port,
1462 struct platform_device *pdev)
1464 struct uart_port *port = &atmel_port->uart;
1465 struct atmel_uart_data *pdata = pdev->dev.platform_data;
1467 if (pdev->dev.of_node) {
1468 atmel_of_init_port(atmel_port, pdev->dev.of_node);
1470 atmel_port->use_dma_rx = pdata->use_dma_rx;
1471 atmel_port->use_dma_tx = pdata->use_dma_tx;
1472 atmel_port->rs485 = pdata->rs485;
1475 port->iotype = UPIO_MEM;
1476 port->flags = UPF_BOOT_AUTOCONF;
1477 port->ops = &atmel_pops;
1479 port->dev = &pdev->dev;
1480 port->mapbase = pdev->resource[0].start;
1481 port->irq = pdev->resource[1].start;
1483 tasklet_init(&atmel_port->tasklet, atmel_tasklet_func,
1484 (unsigned long)port);
1486 memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
1488 if (pdata && pdata->regs) {
1489 /* Already mapped by setup code */
1490 port->membase = pdata->regs;
1492 port->flags |= UPF_IOREMAP;
1493 port->membase = NULL;
1496 /* for console, the clock could already be configured */
1497 if (!atmel_port->clk) {
1498 atmel_port->clk = clk_get(&pdev->dev, "usart");
1499 clk_enable(atmel_port->clk);
1500 port->uartclk = clk_get_rate(atmel_port->clk);
1501 clk_disable(atmel_port->clk);
1502 /* only enable clock when USART is in use */
1505 /* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
1506 if (atmel_port->rs485.flags & SER_RS485_ENABLED)
1507 atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
1508 else if (atmel_use_dma_tx(port)) {
1509 port->fifosize = PDC_BUFFER_SIZE;
1510 atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE;
1512 atmel_port->tx_done_mask = ATMEL_US_TXRDY;
1516 struct platform_device *atmel_default_console_device; /* the serial console device */
1518 #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
1519 static void atmel_console_putchar(struct uart_port *port, int ch)
1521 while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
1523 UART_PUT_CHAR(port, ch);
1527 * Interrupts are disabled on entering
1529 static void atmel_console_write(struct console *co, const char *s, u_int count)
1531 struct uart_port *port = &atmel_ports[co->index].uart;
1532 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1533 unsigned int status, imr;
1534 unsigned int pdc_tx;
1537 * First, save IMR and then disable interrupts
1539 imr = UART_GET_IMR(port);
1540 UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask);
1542 /* Store PDC transmit status and disable it */
1543 pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN;
1544 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
1546 uart_console_write(port, s, count, atmel_console_putchar);
1549 * Finally, wait for transmitter to become empty
1553 status = UART_GET_CSR(port);
1554 } while (!(status & ATMEL_US_TXRDY));
1556 /* Restore PDC transmit status */
1558 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
1560 /* set interrupts back the way they were */
1561 UART_PUT_IER(port, imr);
1565 * If the port was already initialised (eg, by a boot loader),
1566 * try to determine the current setup.
1568 static void __init atmel_console_get_options(struct uart_port *port, int *baud,
1569 int *parity, int *bits)
1571 unsigned int mr, quot;
1574 * If the baud rate generator isn't running, the port wasn't
1575 * initialized by the boot loader.
1577 quot = UART_GET_BRGR(port) & ATMEL_US_CD;
1581 mr = UART_GET_MR(port) & ATMEL_US_CHRL;
1582 if (mr == ATMEL_US_CHRL_8)
1587 mr = UART_GET_MR(port) & ATMEL_US_PAR;
1588 if (mr == ATMEL_US_PAR_EVEN)
1590 else if (mr == ATMEL_US_PAR_ODD)
1594 * The serial core only rounds down when matching this to a
1595 * supported baud rate. Make sure we don't end up slightly
1596 * lower than one of those, as it would make us fall through
1597 * to a much lower baud rate than we really want.
1599 *baud = port->uartclk / (16 * (quot - 1));
1602 static int __init atmel_console_setup(struct console *co, char *options)
1604 struct uart_port *port = &atmel_ports[co->index].uart;
1610 if (port->membase == NULL) {
1611 /* Port not initialized yet - delay setup */
1615 clk_enable(atmel_ports[co->index].clk);
1617 UART_PUT_IDR(port, -1);
1618 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1619 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1622 uart_parse_options(options, &baud, &parity, &bits, &flow);
1624 atmel_console_get_options(port, &baud, &parity, &bits);
1626 return uart_set_options(port, co, baud, parity, bits, flow);
1629 static struct uart_driver atmel_uart;
1631 static struct console atmel_console = {
1632 .name = ATMEL_DEVICENAME,
1633 .write = atmel_console_write,
1634 .device = uart_console_device,
1635 .setup = atmel_console_setup,
1636 .flags = CON_PRINTBUFFER,
1638 .data = &atmel_uart,
1641 #define ATMEL_CONSOLE_DEVICE (&atmel_console)
1644 * Early console initialization (before VM subsystem initialized).
1646 static int __init atmel_console_init(void)
1648 if (atmel_default_console_device) {
1649 struct atmel_uart_data *pdata =
1650 atmel_default_console_device->dev.platform_data;
1651 int id = pdata->num;
1652 struct atmel_uart_port *port = &atmel_ports[id];
1654 port->backup_imr = 0;
1655 port->uart.line = id;
1657 add_preferred_console(ATMEL_DEVICENAME, id, NULL);
1658 atmel_init_port(port, atmel_default_console_device);
1659 register_console(&atmel_console);
1665 console_initcall(atmel_console_init);
1668 * Late console initialization.
1670 static int __init atmel_late_console_init(void)
1672 if (atmel_default_console_device
1673 && !(atmel_console.flags & CON_ENABLED))
1674 register_console(&atmel_console);
1679 core_initcall(atmel_late_console_init);
1681 static inline bool atmel_is_console_port(struct uart_port *port)
1683 return port->cons && port->cons->index == port->line;
1687 #define ATMEL_CONSOLE_DEVICE NULL
1689 static inline bool atmel_is_console_port(struct uart_port *port)
1695 static struct uart_driver atmel_uart = {
1696 .owner = THIS_MODULE,
1697 .driver_name = "atmel_serial",
1698 .dev_name = ATMEL_DEVICENAME,
1699 .major = SERIAL_ATMEL_MAJOR,
1700 .minor = MINOR_START,
1701 .nr = ATMEL_MAX_UART,
1702 .cons = ATMEL_CONSOLE_DEVICE,
1706 static bool atmel_serial_clk_will_stop(void)
1708 #ifdef CONFIG_ARCH_AT91
1709 return at91_suspend_entering_slow_clock();
1715 static int atmel_serial_suspend(struct platform_device *pdev,
1718 struct uart_port *port = platform_get_drvdata(pdev);
1719 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1721 if (atmel_is_console_port(port) && console_suspend_enabled) {
1722 /* Drain the TX shifter */
1723 while (!(UART_GET_CSR(port) & ATMEL_US_TXEMPTY))
1727 /* we can not wake up if we're running on slow clock */
1728 atmel_port->may_wakeup = device_may_wakeup(&pdev->dev);
1729 if (atmel_serial_clk_will_stop())
1730 device_set_wakeup_enable(&pdev->dev, 0);
1732 uart_suspend_port(&atmel_uart, port);
1737 static int atmel_serial_resume(struct platform_device *pdev)
1739 struct uart_port *port = platform_get_drvdata(pdev);
1740 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1742 uart_resume_port(&atmel_uart, port);
1743 device_set_wakeup_enable(&pdev->dev, atmel_port->may_wakeup);
1748 #define atmel_serial_suspend NULL
1749 #define atmel_serial_resume NULL
1752 static int atmel_serial_probe(struct platform_device *pdev)
1754 struct atmel_uart_port *port;
1755 struct device_node *np = pdev->dev.of_node;
1756 struct atmel_uart_data *pdata = pdev->dev.platform_data;
1759 struct pinctrl *pinctrl;
1761 BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
1764 ret = of_alias_get_id(np, "serial");
1770 /* port id not found in platform data nor device-tree aliases:
1771 * auto-enumerate it */
1772 ret = find_first_zero_bit(&atmel_ports_in_use,
1773 sizeof(atmel_ports_in_use));
1775 if (ret > ATMEL_MAX_UART) {
1780 if (test_and_set_bit(ret, &atmel_ports_in_use)) {
1781 /* port already in use */
1786 port = &atmel_ports[ret];
1787 port->backup_imr = 0;
1788 port->uart.line = ret;
1790 atmel_init_port(port, pdev);
1792 pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
1793 if (IS_ERR(pinctrl)) {
1794 ret = PTR_ERR(pinctrl);
1798 if (!atmel_use_dma_rx(&port->uart)) {
1800 data = kmalloc(sizeof(struct atmel_uart_char)
1801 * ATMEL_SERIAL_RINGSIZE, GFP_KERNEL);
1803 goto err_alloc_ring;
1804 port->rx_ring.buf = data;
1807 ret = uart_add_one_port(&atmel_uart, &port->uart);
1811 #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
1812 if (atmel_is_console_port(&port->uart)
1813 && ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) {
1815 * The serial core enabled the clock for us, so undo
1816 * the clk_enable() in atmel_console_setup()
1818 clk_disable(port->clk);
1822 device_init_wakeup(&pdev->dev, 1);
1823 platform_set_drvdata(pdev, port);
1825 if (port->rs485.flags & SER_RS485_ENABLED) {
1826 UART_PUT_MR(&port->uart, ATMEL_US_USMODE_NORMAL);
1827 UART_PUT_CR(&port->uart, ATMEL_US_RTSEN);
1833 kfree(port->rx_ring.buf);
1834 port->rx_ring.buf = NULL;
1836 if (!atmel_is_console_port(&port->uart)) {
1844 static int atmel_serial_remove(struct platform_device *pdev)
1846 struct uart_port *port = platform_get_drvdata(pdev);
1847 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1850 device_init_wakeup(&pdev->dev, 0);
1851 platform_set_drvdata(pdev, NULL);
1853 ret = uart_remove_one_port(&atmel_uart, port);
1855 tasklet_kill(&atmel_port->tasklet);
1856 kfree(atmel_port->rx_ring.buf);
1858 /* "port" is allocated statically, so we shouldn't free it */
1860 clear_bit(port->line, &atmel_ports_in_use);
1862 clk_put(atmel_port->clk);
1867 static struct platform_driver atmel_serial_driver = {
1868 .probe = atmel_serial_probe,
1869 .remove = atmel_serial_remove,
1870 .suspend = atmel_serial_suspend,
1871 .resume = atmel_serial_resume,
1873 .name = "atmel_usart",
1874 .owner = THIS_MODULE,
1875 .of_match_table = of_match_ptr(atmel_serial_dt_ids),
1879 static int __init atmel_serial_init(void)
1883 ret = uart_register_driver(&atmel_uart);
1887 ret = platform_driver_register(&atmel_serial_driver);
1889 uart_unregister_driver(&atmel_uart);
1894 static void __exit atmel_serial_exit(void)
1896 platform_driver_unregister(&atmel_serial_driver);
1897 uart_unregister_driver(&atmel_uart);
1900 module_init(atmel_serial_init);
1901 module_exit(atmel_serial_exit);
1903 MODULE_AUTHOR("Rick Bronson");
1904 MODULE_DESCRIPTION("Atmel AT91 / AT32 serial port driver");
1905 MODULE_LICENSE("GPL");
1906 MODULE_ALIAS("platform:atmel_usart");