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>
44 #include <asm/ioctls.h>
46 #include <asm/mach/serial_at91.h>
47 #include <mach/board.h>
54 #define PDC_BUFFER_SIZE 512
55 /* Revisit: We should calculate this based on the actual port settings */
56 #define PDC_RX_TIMEOUT (3 * 10) /* 3 bytes */
58 #if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
62 #include <linux/serial_core.h>
64 static void atmel_start_rx(struct uart_port *port);
65 static void atmel_stop_rx(struct uart_port *port);
67 #ifdef CONFIG_SERIAL_ATMEL_TTYAT
69 /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we
70 * should coexist with the 8250 driver, such as if we have an external 16C550
72 #define SERIAL_ATMEL_MAJOR 204
73 #define MINOR_START 154
74 #define ATMEL_DEVICENAME "ttyAT"
78 /* Use device name ttyS, major 4, minor 64-68. This is the usual serial port
79 * name, but it is legally reserved for the 8250 driver. */
80 #define SERIAL_ATMEL_MAJOR TTY_MAJOR
81 #define MINOR_START 64
82 #define ATMEL_DEVICENAME "ttyS"
86 #define ATMEL_ISR_PASS_LIMIT 256
88 /* UART registers. CR is write-only, hence no GET macro */
89 #define UART_PUT_CR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_CR)
90 #define UART_GET_MR(port) __raw_readl((port)->membase + ATMEL_US_MR)
91 #define UART_PUT_MR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_MR)
92 #define UART_PUT_IER(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IER)
93 #define UART_PUT_IDR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IDR)
94 #define UART_GET_IMR(port) __raw_readl((port)->membase + ATMEL_US_IMR)
95 #define UART_GET_CSR(port) __raw_readl((port)->membase + ATMEL_US_CSR)
96 #define UART_GET_CHAR(port) __raw_readl((port)->membase + ATMEL_US_RHR)
97 #define UART_PUT_CHAR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_THR)
98 #define UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR)
99 #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_BRGR)
100 #define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_RTOR)
101 #define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase + ATMEL_US_TTGR)
104 #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR)
105 #define UART_GET_PTSR(port) __raw_readl((port)->membase + ATMEL_PDC_PTSR)
107 #define UART_PUT_RPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RPR)
108 #define UART_GET_RPR(port) __raw_readl((port)->membase + ATMEL_PDC_RPR)
109 #define UART_PUT_RCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RCR)
110 #define UART_PUT_RNPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNPR)
111 #define UART_PUT_RNCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNCR)
113 #define UART_PUT_TPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TPR)
114 #define UART_PUT_TCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TCR)
115 #define UART_GET_TCR(port) __raw_readl((port)->membase + ATMEL_PDC_TCR)
117 static int (*atmel_open_hook)(struct uart_port *);
118 static void (*atmel_close_hook)(struct uart_port *);
120 struct atmel_dma_buffer {
123 unsigned int dma_size;
127 struct atmel_uart_char {
132 #define ATMEL_SERIAL_RINGSIZE 1024
135 * We wrap our port structure around the generic uart_port.
137 struct atmel_uart_port {
138 struct uart_port uart; /* uart */
139 struct clk *clk; /* uart clock */
140 int may_wakeup; /* cached value of device_may_wakeup for times we need to disable it */
141 u32 backup_imr; /* IMR saved during suspend */
142 int break_active; /* break being received */
144 short use_dma_rx; /* enable PDC receiver */
145 short pdc_rx_idx; /* current PDC RX buffer */
146 struct atmel_dma_buffer pdc_rx[2]; /* PDC receier */
148 short use_dma_tx; /* enable PDC transmitter */
149 struct atmel_dma_buffer pdc_tx; /* PDC transmitter */
151 struct tasklet_struct tasklet;
152 unsigned int irq_status;
153 unsigned int irq_status_prev;
155 struct circ_buf rx_ring;
157 struct serial_rs485 rs485; /* rs485 settings */
158 unsigned int tx_done_mask;
161 static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
162 static unsigned long atmel_ports_in_use;
165 static struct console atmel_console;
168 #if defined(CONFIG_OF)
169 static const struct of_device_id atmel_serial_dt_ids[] = {
170 { .compatible = "atmel,at91rm9200-usart" },
171 { .compatible = "atmel,at91sam9260-usart" },
175 MODULE_DEVICE_TABLE(of, atmel_serial_dt_ids);
178 static inline struct atmel_uart_port *
179 to_atmel_uart_port(struct uart_port *uart)
181 return container_of(uart, struct atmel_uart_port, uart);
184 #ifdef CONFIG_SERIAL_ATMEL_PDC
185 static bool atmel_use_dma_rx(struct uart_port *port)
187 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
189 return atmel_port->use_dma_rx;
192 static bool atmel_use_dma_tx(struct uart_port *port)
194 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
196 return atmel_port->use_dma_tx;
199 static bool atmel_use_dma_rx(struct uart_port *port)
204 static bool atmel_use_dma_tx(struct uart_port *port)
210 /* Enable or disable the rs485 support */
211 void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
213 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
217 spin_lock_irqsave(&port->lock, flags);
219 /* Disable interrupts */
220 UART_PUT_IDR(port, atmel_port->tx_done_mask);
222 mode = UART_GET_MR(port);
224 /* Resetting serial mode to RS232 (0x0) */
225 mode &= ~ATMEL_US_USMODE;
227 atmel_port->rs485 = *rs485conf;
229 if (rs485conf->flags & SER_RS485_ENABLED) {
230 dev_dbg(port->dev, "Setting UART to RS485\n");
231 atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
232 if ((rs485conf->delay_rts_after_send) > 0)
233 UART_PUT_TTGR(port, rs485conf->delay_rts_after_send);
234 mode |= ATMEL_US_USMODE_RS485;
236 dev_dbg(port->dev, "Setting UART to RS232\n");
237 if (atmel_use_dma_tx(port))
238 atmel_port->tx_done_mask = ATMEL_US_ENDTX |
241 atmel_port->tx_done_mask = ATMEL_US_TXRDY;
243 UART_PUT_MR(port, mode);
245 /* Enable interrupts */
246 UART_PUT_IER(port, atmel_port->tx_done_mask);
248 spin_unlock_irqrestore(&port->lock, flags);
253 * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
255 static u_int atmel_tx_empty(struct uart_port *port)
257 return (UART_GET_CSR(port) & ATMEL_US_TXEMPTY) ? TIOCSER_TEMT : 0;
261 * Set state of the modem control output lines
263 static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
265 unsigned int control = 0;
267 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
269 #ifdef CONFIG_ARCH_AT91RM9200
270 if (cpu_is_at91rm9200()) {
272 * AT91RM9200 Errata #39: RTS0 is not internally connected
273 * to PA21. We need to drive the pin manually.
275 if (port->mapbase == AT91RM9200_BASE_US0) {
276 if (mctrl & TIOCM_RTS)
277 at91_set_gpio_value(AT91_PIN_PA21, 0);
279 at91_set_gpio_value(AT91_PIN_PA21, 1);
284 if (mctrl & TIOCM_RTS)
285 control |= ATMEL_US_RTSEN;
287 control |= ATMEL_US_RTSDIS;
289 if (mctrl & TIOCM_DTR)
290 control |= ATMEL_US_DTREN;
292 control |= ATMEL_US_DTRDIS;
294 UART_PUT_CR(port, control);
296 /* Local loopback mode? */
297 mode = UART_GET_MR(port) & ~ATMEL_US_CHMODE;
298 if (mctrl & TIOCM_LOOP)
299 mode |= ATMEL_US_CHMODE_LOC_LOOP;
301 mode |= ATMEL_US_CHMODE_NORMAL;
303 /* Resetting serial mode to RS232 (0x0) */
304 mode &= ~ATMEL_US_USMODE;
306 if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
307 dev_dbg(port->dev, "Setting UART to RS485\n");
308 if ((atmel_port->rs485.delay_rts_after_send) > 0)
310 atmel_port->rs485.delay_rts_after_send);
311 mode |= ATMEL_US_USMODE_RS485;
313 dev_dbg(port->dev, "Setting UART to RS232\n");
315 UART_PUT_MR(port, mode);
319 * Get state of the modem control input lines
321 static u_int atmel_get_mctrl(struct uart_port *port)
323 unsigned int status, ret = 0;
325 status = UART_GET_CSR(port);
328 * The control signals are active low.
330 if (!(status & ATMEL_US_DCD))
332 if (!(status & ATMEL_US_CTS))
334 if (!(status & ATMEL_US_DSR))
336 if (!(status & ATMEL_US_RI))
345 static void atmel_stop_tx(struct uart_port *port)
347 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
349 if (atmel_use_dma_tx(port)) {
350 /* disable PDC transmit */
351 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
353 /* Disable interrupts */
354 UART_PUT_IDR(port, atmel_port->tx_done_mask);
356 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
357 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
358 atmel_start_rx(port);
362 * Start transmitting.
364 static void atmel_start_tx(struct uart_port *port)
366 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
368 if (atmel_use_dma_tx(port)) {
369 if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN)
370 /* The transmitter is already running. Yes, we
374 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
375 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
378 /* re-enable PDC transmit */
379 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
381 /* Enable interrupts */
382 UART_PUT_IER(port, atmel_port->tx_done_mask);
386 * start receiving - port is in process of being opened.
388 static void atmel_start_rx(struct uart_port *port)
390 UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */
392 if (atmel_use_dma_rx(port)) {
393 /* enable PDC controller */
394 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
395 port->read_status_mask);
396 UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
398 UART_PUT_IER(port, ATMEL_US_RXRDY);
403 * Stop receiving - port is in process of being closed.
405 static void atmel_stop_rx(struct uart_port *port)
407 if (atmel_use_dma_rx(port)) {
408 /* disable PDC receive */
409 UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS);
410 UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
411 port->read_status_mask);
413 UART_PUT_IDR(port, ATMEL_US_RXRDY);
418 * Enable modem status interrupts
420 static void atmel_enable_ms(struct uart_port *port)
422 UART_PUT_IER(port, ATMEL_US_RIIC | ATMEL_US_DSRIC
423 | ATMEL_US_DCDIC | ATMEL_US_CTSIC);
427 * Control the transmission of a break signal
429 static void atmel_break_ctl(struct uart_port *port, int break_state)
431 if (break_state != 0)
432 UART_PUT_CR(port, ATMEL_US_STTBRK); /* start break */
434 UART_PUT_CR(port, ATMEL_US_STPBRK); /* stop break */
438 * Stores the incoming character in the ring buffer
441 atmel_buffer_rx_char(struct uart_port *port, unsigned int status,
444 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
445 struct circ_buf *ring = &atmel_port->rx_ring;
446 struct atmel_uart_char *c;
448 if (!CIRC_SPACE(ring->head, ring->tail, ATMEL_SERIAL_RINGSIZE))
449 /* Buffer overflow, ignore char */
452 c = &((struct atmel_uart_char *)ring->buf)[ring->head];
456 /* Make sure the character is stored before we update head. */
459 ring->head = (ring->head + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
463 * Deal with parity, framing and overrun errors.
465 static void atmel_pdc_rxerr(struct uart_port *port, unsigned int status)
468 UART_PUT_CR(port, ATMEL_US_RSTSTA);
470 if (status & ATMEL_US_RXBRK) {
471 /* ignore side-effect */
472 status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
475 if (status & ATMEL_US_PARE)
476 port->icount.parity++;
477 if (status & ATMEL_US_FRAME)
478 port->icount.frame++;
479 if (status & ATMEL_US_OVRE)
480 port->icount.overrun++;
484 * Characters received (called from interrupt handler)
486 static void atmel_rx_chars(struct uart_port *port)
488 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
489 unsigned int status, ch;
491 status = UART_GET_CSR(port);
492 while (status & ATMEL_US_RXRDY) {
493 ch = UART_GET_CHAR(port);
496 * note that the error handling code is
497 * out of the main execution path
499 if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
500 | ATMEL_US_OVRE | ATMEL_US_RXBRK)
501 || atmel_port->break_active)) {
504 UART_PUT_CR(port, ATMEL_US_RSTSTA);
506 if (status & ATMEL_US_RXBRK
507 && !atmel_port->break_active) {
508 atmel_port->break_active = 1;
509 UART_PUT_IER(port, ATMEL_US_RXBRK);
512 * This is either the end-of-break
513 * condition or we've received at
514 * least one character without RXBRK
515 * being set. In both cases, the next
516 * RXBRK will indicate start-of-break.
518 UART_PUT_IDR(port, ATMEL_US_RXBRK);
519 status &= ~ATMEL_US_RXBRK;
520 atmel_port->break_active = 0;
524 atmel_buffer_rx_char(port, status, ch);
525 status = UART_GET_CSR(port);
528 tasklet_schedule(&atmel_port->tasklet);
532 * Transmit characters (called from tasklet with TXRDY interrupt
535 static void atmel_tx_chars(struct uart_port *port)
537 struct circ_buf *xmit = &port->state->xmit;
538 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
540 if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) {
541 UART_PUT_CHAR(port, port->x_char);
545 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
548 while (UART_GET_CSR(port) & atmel_port->tx_done_mask) {
549 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
550 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
552 if (uart_circ_empty(xmit))
556 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
557 uart_write_wakeup(port);
559 if (!uart_circ_empty(xmit))
560 /* Enable interrupts */
561 UART_PUT_IER(port, atmel_port->tx_done_mask);
565 * receive interrupt handler.
568 atmel_handle_receive(struct uart_port *port, unsigned int pending)
570 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
572 if (atmel_use_dma_rx(port)) {
574 * PDC receive. Just schedule the tasklet and let it
575 * figure out the details.
577 * TODO: We're not handling error flags correctly at
580 if (pending & (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)) {
581 UART_PUT_IDR(port, (ATMEL_US_ENDRX
582 | ATMEL_US_TIMEOUT));
583 tasklet_schedule(&atmel_port->tasklet);
586 if (pending & (ATMEL_US_RXBRK | ATMEL_US_OVRE |
587 ATMEL_US_FRAME | ATMEL_US_PARE))
588 atmel_pdc_rxerr(port, pending);
591 /* Interrupt receive */
592 if (pending & ATMEL_US_RXRDY)
593 atmel_rx_chars(port);
594 else if (pending & ATMEL_US_RXBRK) {
596 * End of break detected. If it came along with a
597 * character, atmel_rx_chars will handle it.
599 UART_PUT_CR(port, ATMEL_US_RSTSTA);
600 UART_PUT_IDR(port, ATMEL_US_RXBRK);
601 atmel_port->break_active = 0;
606 * transmit interrupt handler. (Transmit is IRQF_NODELAY safe)
609 atmel_handle_transmit(struct uart_port *port, unsigned int pending)
611 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
613 if (pending & atmel_port->tx_done_mask) {
614 /* Either PDC or interrupt transmission */
615 UART_PUT_IDR(port, atmel_port->tx_done_mask);
616 tasklet_schedule(&atmel_port->tasklet);
621 * status flags interrupt handler.
624 atmel_handle_status(struct uart_port *port, unsigned int pending,
627 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
629 if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC
631 atmel_port->irq_status = status;
632 tasklet_schedule(&atmel_port->tasklet);
639 static irqreturn_t atmel_interrupt(int irq, void *dev_id)
641 struct uart_port *port = dev_id;
642 unsigned int status, pending, pass_counter = 0;
645 status = UART_GET_CSR(port);
646 pending = status & UART_GET_IMR(port);
650 atmel_handle_receive(port, pending);
651 atmel_handle_status(port, pending, status);
652 atmel_handle_transmit(port, pending);
653 } while (pass_counter++ < ATMEL_ISR_PASS_LIMIT);
655 return pass_counter ? IRQ_HANDLED : IRQ_NONE;
659 * Called from tasklet with ENDTX and TXBUFE interrupts disabled.
661 static void atmel_tx_dma(struct uart_port *port)
663 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
664 struct circ_buf *xmit = &port->state->xmit;
665 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
668 /* nothing left to transmit? */
669 if (UART_GET_TCR(port))
672 xmit->tail += pdc->ofs;
673 xmit->tail &= UART_XMIT_SIZE - 1;
675 port->icount.tx += pdc->ofs;
678 /* more to transmit - setup next transfer */
680 /* disable PDC transmit */
681 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
683 if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
684 dma_sync_single_for_device(port->dev,
689 count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
692 UART_PUT_TPR(port, pdc->dma_addr + xmit->tail);
693 UART_PUT_TCR(port, count);
694 /* re-enable PDC transmit */
695 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
696 /* Enable interrupts */
697 UART_PUT_IER(port, atmel_port->tx_done_mask);
699 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
700 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX)) {
701 /* DMA done, stop TX, start RX for RS485 */
702 atmel_start_rx(port);
706 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
707 uart_write_wakeup(port);
710 static void atmel_rx_from_ring(struct uart_port *port)
712 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
713 struct circ_buf *ring = &atmel_port->rx_ring;
717 while (ring->head != ring->tail) {
718 struct atmel_uart_char c;
720 /* Make sure c is loaded after head. */
723 c = ((struct atmel_uart_char *)ring->buf)[ring->tail];
725 ring->tail = (ring->tail + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
732 * note that the error handling code is
733 * out of the main execution path
735 if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
736 | ATMEL_US_OVRE | ATMEL_US_RXBRK))) {
737 if (status & ATMEL_US_RXBRK) {
738 /* ignore side-effect */
739 status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
742 if (uart_handle_break(port))
745 if (status & ATMEL_US_PARE)
746 port->icount.parity++;
747 if (status & ATMEL_US_FRAME)
748 port->icount.frame++;
749 if (status & ATMEL_US_OVRE)
750 port->icount.overrun++;
752 status &= port->read_status_mask;
754 if (status & ATMEL_US_RXBRK)
756 else if (status & ATMEL_US_PARE)
758 else if (status & ATMEL_US_FRAME)
763 if (uart_handle_sysrq_char(port, c.ch))
766 uart_insert_char(port, status, ATMEL_US_OVRE, c.ch, flg);
770 * Drop the lock here since it might end up calling
771 * uart_start(), which takes the lock.
773 spin_unlock(&port->lock);
774 tty_flip_buffer_push(port->state->port.tty);
775 spin_lock(&port->lock);
778 static void atmel_rx_from_dma(struct uart_port *port)
780 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
781 struct tty_struct *tty = port->state->port.tty;
782 struct atmel_dma_buffer *pdc;
783 int rx_idx = atmel_port->pdc_rx_idx;
789 /* Reset the UART timeout early so that we don't miss one */
790 UART_PUT_CR(port, ATMEL_US_STTTO);
792 pdc = &atmel_port->pdc_rx[rx_idx];
793 head = UART_GET_RPR(port) - pdc->dma_addr;
796 /* If the PDC has switched buffers, RPR won't contain
797 * any address within the current buffer. Since head
798 * is unsigned, we just need a one-way comparison to
801 * In this case, we just need to consume the entire
802 * buffer and resubmit it for DMA. This will clear the
803 * ENDRX bit as well, so that we can safely re-enable
804 * all interrupts below.
806 head = min(head, pdc->dma_size);
808 if (likely(head != tail)) {
809 dma_sync_single_for_cpu(port->dev, pdc->dma_addr,
810 pdc->dma_size, DMA_FROM_DEVICE);
813 * head will only wrap around when we recycle
814 * the DMA buffer, and when that happens, we
815 * explicitly set tail to 0. So head will
816 * always be greater than tail.
820 tty_insert_flip_string(tty, pdc->buf + pdc->ofs, count);
822 dma_sync_single_for_device(port->dev, pdc->dma_addr,
823 pdc->dma_size, DMA_FROM_DEVICE);
825 port->icount.rx += count;
830 * If the current buffer is full, we need to check if
831 * the next one contains any additional data.
833 if (head >= pdc->dma_size) {
835 UART_PUT_RNPR(port, pdc->dma_addr);
836 UART_PUT_RNCR(port, pdc->dma_size);
839 atmel_port->pdc_rx_idx = rx_idx;
841 } while (head >= pdc->dma_size);
844 * Drop the lock here since it might end up calling
845 * uart_start(), which takes the lock.
847 spin_unlock(&port->lock);
848 tty_flip_buffer_push(tty);
849 spin_lock(&port->lock);
851 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
855 * tasklet handling tty stuff outside the interrupt handler.
857 static void atmel_tasklet_func(unsigned long data)
859 struct uart_port *port = (struct uart_port *)data;
860 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
862 unsigned int status_change;
864 /* The interrupt handler does not take the lock */
865 spin_lock(&port->lock);
867 if (atmel_use_dma_tx(port))
870 atmel_tx_chars(port);
872 status = atmel_port->irq_status;
873 status_change = status ^ atmel_port->irq_status_prev;
875 if (status_change & (ATMEL_US_RI | ATMEL_US_DSR
876 | ATMEL_US_DCD | ATMEL_US_CTS)) {
877 /* TODO: All reads to CSR will clear these interrupts! */
878 if (status_change & ATMEL_US_RI)
880 if (status_change & ATMEL_US_DSR)
882 if (status_change & ATMEL_US_DCD)
883 uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
884 if (status_change & ATMEL_US_CTS)
885 uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
887 wake_up_interruptible(&port->state->port.delta_msr_wait);
889 atmel_port->irq_status_prev = status;
892 if (atmel_use_dma_rx(port))
893 atmel_rx_from_dma(port);
895 atmel_rx_from_ring(port);
897 spin_unlock(&port->lock);
901 * Perform initialization and enable port for reception
903 static int atmel_startup(struct uart_port *port)
905 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
906 struct tty_struct *tty = port->state->port.tty;
910 * Ensure that no interrupts are enabled otherwise when
911 * request_irq() is called we could get stuck trying to
912 * handle an unexpected interrupt
914 UART_PUT_IDR(port, -1);
919 retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED,
920 tty ? tty->name : "atmel_serial", port);
922 printk("atmel_serial: atmel_startup - Can't get irq\n");
927 * Initialize DMA (if necessary)
929 if (atmel_use_dma_rx(port)) {
932 for (i = 0; i < 2; i++) {
933 struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
935 pdc->buf = kmalloc(PDC_BUFFER_SIZE, GFP_KERNEL);
936 if (pdc->buf == NULL) {
938 dma_unmap_single(port->dev,
939 atmel_port->pdc_rx[0].dma_addr,
942 kfree(atmel_port->pdc_rx[0].buf);
944 free_irq(port->irq, port);
947 pdc->dma_addr = dma_map_single(port->dev,
951 pdc->dma_size = PDC_BUFFER_SIZE;
955 atmel_port->pdc_rx_idx = 0;
957 UART_PUT_RPR(port, atmel_port->pdc_rx[0].dma_addr);
958 UART_PUT_RCR(port, PDC_BUFFER_SIZE);
960 UART_PUT_RNPR(port, atmel_port->pdc_rx[1].dma_addr);
961 UART_PUT_RNCR(port, PDC_BUFFER_SIZE);
963 if (atmel_use_dma_tx(port)) {
964 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
965 struct circ_buf *xmit = &port->state->xmit;
967 pdc->buf = xmit->buf;
968 pdc->dma_addr = dma_map_single(port->dev,
972 pdc->dma_size = UART_XMIT_SIZE;
977 * If there is a specific "open" function (to register
978 * control line interrupts)
980 if (atmel_open_hook) {
981 retval = atmel_open_hook(port);
983 free_irq(port->irq, port);
988 /* Save current CSR for comparison in atmel_tasklet_func() */
989 atmel_port->irq_status_prev = UART_GET_CSR(port);
990 atmel_port->irq_status = atmel_port->irq_status_prev;
993 * Finally, enable the serial port
995 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
996 /* enable xmit & rcvr */
997 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
999 if (atmel_use_dma_rx(port)) {
1000 /* set UART timeout */
1001 UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
1002 UART_PUT_CR(port, ATMEL_US_STTTO);
1004 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
1005 /* enable PDC controller */
1006 UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
1008 /* enable receive only */
1009 UART_PUT_IER(port, ATMEL_US_RXRDY);
1018 static void atmel_shutdown(struct uart_port *port)
1020 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1022 * Ensure everything is stopped.
1024 atmel_stop_rx(port);
1025 atmel_stop_tx(port);
1028 * Shut-down the DMA.
1030 if (atmel_use_dma_rx(port)) {
1033 for (i = 0; i < 2; i++) {
1034 struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
1036 dma_unmap_single(port->dev,
1043 if (atmel_use_dma_tx(port)) {
1044 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
1046 dma_unmap_single(port->dev,
1053 * Disable all interrupts, port and break condition.
1055 UART_PUT_CR(port, ATMEL_US_RSTSTA);
1056 UART_PUT_IDR(port, -1);
1059 * Free the interrupt
1061 free_irq(port->irq, port);
1064 * If there is a specific "close" function (to unregister
1065 * control line interrupts)
1067 if (atmel_close_hook)
1068 atmel_close_hook(port);
1072 * Flush any TX data submitted for DMA. Called when the TX circular
1075 static void atmel_flush_buffer(struct uart_port *port)
1077 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1079 if (atmel_use_dma_tx(port)) {
1080 UART_PUT_TCR(port, 0);
1081 atmel_port->pdc_tx.ofs = 0;
1086 * Power / Clock management.
1088 static void atmel_serial_pm(struct uart_port *port, unsigned int state,
1089 unsigned int oldstate)
1091 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1096 * Enable the peripheral clock for this serial port.
1097 * This is called on uart_open() or a resume event.
1099 clk_enable(atmel_port->clk);
1101 /* re-enable interrupts if we disabled some on suspend */
1102 UART_PUT_IER(port, atmel_port->backup_imr);
1105 /* Back up the interrupt mask and disable all interrupts */
1106 atmel_port->backup_imr = UART_GET_IMR(port);
1107 UART_PUT_IDR(port, -1);
1110 * Disable the peripheral clock for this serial port.
1111 * This is called on uart_close() or a suspend event.
1113 clk_disable(atmel_port->clk);
1116 printk(KERN_ERR "atmel_serial: unknown pm %d\n", state);
1121 * Change the port parameters
1123 static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
1124 struct ktermios *old)
1126 unsigned long flags;
1127 unsigned int mode, imr, quot, baud;
1128 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1130 /* Get current mode register */
1131 mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL
1132 | ATMEL_US_NBSTOP | ATMEL_US_PAR
1135 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
1136 quot = uart_get_divisor(port, baud);
1138 if (quot > 65535) { /* BRGR is 16-bit, so switch to slower clock */
1140 mode |= ATMEL_US_USCLKS_MCK_DIV8;
1144 switch (termios->c_cflag & CSIZE) {
1146 mode |= ATMEL_US_CHRL_5;
1149 mode |= ATMEL_US_CHRL_6;
1152 mode |= ATMEL_US_CHRL_7;
1155 mode |= ATMEL_US_CHRL_8;
1160 if (termios->c_cflag & CSTOPB)
1161 mode |= ATMEL_US_NBSTOP_2;
1164 if (termios->c_cflag & PARENB) {
1165 /* Mark or Space parity */
1166 if (termios->c_cflag & CMSPAR) {
1167 if (termios->c_cflag & PARODD)
1168 mode |= ATMEL_US_PAR_MARK;
1170 mode |= ATMEL_US_PAR_SPACE;
1171 } else if (termios->c_cflag & PARODD)
1172 mode |= ATMEL_US_PAR_ODD;
1174 mode |= ATMEL_US_PAR_EVEN;
1176 mode |= ATMEL_US_PAR_NONE;
1178 /* hardware handshake (RTS/CTS) */
1179 if (termios->c_cflag & CRTSCTS)
1180 mode |= ATMEL_US_USMODE_HWHS;
1182 mode |= ATMEL_US_USMODE_NORMAL;
1184 spin_lock_irqsave(&port->lock, flags);
1186 port->read_status_mask = ATMEL_US_OVRE;
1187 if (termios->c_iflag & INPCK)
1188 port->read_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
1189 if (termios->c_iflag & (BRKINT | PARMRK))
1190 port->read_status_mask |= ATMEL_US_RXBRK;
1192 if (atmel_use_dma_rx(port))
1193 /* need to enable error interrupts */
1194 UART_PUT_IER(port, port->read_status_mask);
1197 * Characters to ignore
1199 port->ignore_status_mask = 0;
1200 if (termios->c_iflag & IGNPAR)
1201 port->ignore_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
1202 if (termios->c_iflag & IGNBRK) {
1203 port->ignore_status_mask |= ATMEL_US_RXBRK;
1205 * If we're ignoring parity and break indicators,
1206 * ignore overruns too (for real raw support).
1208 if (termios->c_iflag & IGNPAR)
1209 port->ignore_status_mask |= ATMEL_US_OVRE;
1211 /* TODO: Ignore all characters if CREAD is set.*/
1213 /* update the per-port timeout */
1214 uart_update_timeout(port, termios->c_cflag, baud);
1217 * save/disable interrupts. The tty layer will ensure that the
1218 * transmitter is empty if requested by the caller, so there's
1219 * no need to wait for it here.
1221 imr = UART_GET_IMR(port);
1222 UART_PUT_IDR(port, -1);
1224 /* disable receiver and transmitter */
1225 UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
1227 /* Resetting serial mode to RS232 (0x0) */
1228 mode &= ~ATMEL_US_USMODE;
1230 if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
1231 dev_dbg(port->dev, "Setting UART to RS485\n");
1232 if ((atmel_port->rs485.delay_rts_after_send) > 0)
1234 atmel_port->rs485.delay_rts_after_send);
1235 mode |= ATMEL_US_USMODE_RS485;
1237 dev_dbg(port->dev, "Setting UART to RS232\n");
1240 /* set the parity, stop bits and data size */
1241 UART_PUT_MR(port, mode);
1243 /* set the baud rate */
1244 UART_PUT_BRGR(port, quot);
1245 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1246 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1248 /* restore interrupts */
1249 UART_PUT_IER(port, imr);
1251 /* CTS flow-control and modem-status interrupts */
1252 if (UART_ENABLE_MS(port, termios->c_cflag))
1253 port->ops->enable_ms(port);
1255 spin_unlock_irqrestore(&port->lock, flags);
1258 static void atmel_set_ldisc(struct uart_port *port, int new)
1260 int line = port->line;
1262 if (line >= port->state->port.tty->driver->num)
1265 if (port->state->port.tty->ldisc->ops->num == N_PPS) {
1266 port->flags |= UPF_HARDPPS_CD;
1267 atmel_enable_ms(port);
1269 port->flags &= ~UPF_HARDPPS_CD;
1274 * Return string describing the specified port
1276 static const char *atmel_type(struct uart_port *port)
1278 return (port->type == PORT_ATMEL) ? "ATMEL_SERIAL" : NULL;
1282 * Release the memory region(s) being used by 'port'.
1284 static void atmel_release_port(struct uart_port *port)
1286 struct platform_device *pdev = to_platform_device(port->dev);
1287 int size = pdev->resource[0].end - pdev->resource[0].start + 1;
1289 release_mem_region(port->mapbase, size);
1291 if (port->flags & UPF_IOREMAP) {
1292 iounmap(port->membase);
1293 port->membase = NULL;
1298 * Request the memory region(s) being used by 'port'.
1300 static int atmel_request_port(struct uart_port *port)
1302 struct platform_device *pdev = to_platform_device(port->dev);
1303 int size = pdev->resource[0].end - pdev->resource[0].start + 1;
1305 if (!request_mem_region(port->mapbase, size, "atmel_serial"))
1308 if (port->flags & UPF_IOREMAP) {
1309 port->membase = ioremap(port->mapbase, size);
1310 if (port->membase == NULL) {
1311 release_mem_region(port->mapbase, size);
1320 * Configure/autoconfigure the port.
1322 static void atmel_config_port(struct uart_port *port, int flags)
1324 if (flags & UART_CONFIG_TYPE) {
1325 port->type = PORT_ATMEL;
1326 atmel_request_port(port);
1331 * Verify the new serial_struct (for TIOCSSERIAL).
1333 static int atmel_verify_port(struct uart_port *port, struct serial_struct *ser)
1336 if (ser->type != PORT_UNKNOWN && ser->type != PORT_ATMEL)
1338 if (port->irq != ser->irq)
1340 if (ser->io_type != SERIAL_IO_MEM)
1342 if (port->uartclk / 16 != ser->baud_base)
1344 if ((void *)port->mapbase != ser->iomem_base)
1346 if (port->iobase != ser->port)
1353 #ifdef CONFIG_CONSOLE_POLL
1354 static int atmel_poll_get_char(struct uart_port *port)
1356 while (!(UART_GET_CSR(port) & ATMEL_US_RXRDY))
1359 return UART_GET_CHAR(port);
1362 static void atmel_poll_put_char(struct uart_port *port, unsigned char ch)
1364 while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
1367 UART_PUT_CHAR(port, ch);
1372 atmel_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg)
1374 struct serial_rs485 rs485conf;
1378 if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg,
1382 atmel_config_rs485(port, &rs485conf);
1386 if (copy_to_user((struct serial_rs485 *) arg,
1387 &(to_atmel_uart_port(port)->rs485),
1393 return -ENOIOCTLCMD;
1400 static struct uart_ops atmel_pops = {
1401 .tx_empty = atmel_tx_empty,
1402 .set_mctrl = atmel_set_mctrl,
1403 .get_mctrl = atmel_get_mctrl,
1404 .stop_tx = atmel_stop_tx,
1405 .start_tx = atmel_start_tx,
1406 .stop_rx = atmel_stop_rx,
1407 .enable_ms = atmel_enable_ms,
1408 .break_ctl = atmel_break_ctl,
1409 .startup = atmel_startup,
1410 .shutdown = atmel_shutdown,
1411 .flush_buffer = atmel_flush_buffer,
1412 .set_termios = atmel_set_termios,
1413 .set_ldisc = atmel_set_ldisc,
1415 .release_port = atmel_release_port,
1416 .request_port = atmel_request_port,
1417 .config_port = atmel_config_port,
1418 .verify_port = atmel_verify_port,
1419 .pm = atmel_serial_pm,
1420 .ioctl = atmel_ioctl,
1421 #ifdef CONFIG_CONSOLE_POLL
1422 .poll_get_char = atmel_poll_get_char,
1423 .poll_put_char = atmel_poll_put_char,
1427 static void __devinit atmel_of_init_port(struct atmel_uart_port *atmel_port,
1428 struct device_node *np)
1432 /* DMA/PDC usage specification */
1433 if (of_get_property(np, "atmel,use-dma-rx", NULL))
1434 atmel_port->use_dma_rx = 1;
1436 atmel_port->use_dma_rx = 0;
1437 if (of_get_property(np, "atmel,use-dma-tx", NULL))
1438 atmel_port->use_dma_tx = 1;
1440 atmel_port->use_dma_tx = 0;
1442 /* rs485 properties */
1443 if (of_property_read_u32_array(np, "rs485-rts-delay",
1444 rs485_delay, 2) == 0) {
1445 struct serial_rs485 *rs485conf = &atmel_port->rs485;
1447 rs485conf->delay_rts_before_send = rs485_delay[0];
1448 rs485conf->delay_rts_after_send = rs485_delay[1];
1449 rs485conf->flags = 0;
1451 if (of_get_property(np, "rs485-rx-during-tx", NULL))
1452 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1454 if (of_get_property(np, "linux,rs485-enabled-at-boot-time", NULL))
1455 rs485conf->flags |= SER_RS485_ENABLED;
1460 * Configure the port from the platform device resource info.
1462 static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
1463 struct platform_device *pdev)
1465 struct uart_port *port = &atmel_port->uart;
1466 struct atmel_uart_data *pdata = pdev->dev.platform_data;
1468 if (pdev->dev.of_node) {
1469 atmel_of_init_port(atmel_port, pdev->dev.of_node);
1471 atmel_port->use_dma_rx = pdata->use_dma_rx;
1472 atmel_port->use_dma_tx = pdata->use_dma_tx;
1473 atmel_port->rs485 = pdata->rs485;
1476 port->iotype = UPIO_MEM;
1477 port->flags = UPF_BOOT_AUTOCONF;
1478 port->ops = &atmel_pops;
1480 port->dev = &pdev->dev;
1481 port->mapbase = pdev->resource[0].start;
1482 port->irq = pdev->resource[1].start;
1484 tasklet_init(&atmel_port->tasklet, atmel_tasklet_func,
1485 (unsigned long)port);
1487 memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
1489 if (pdata && pdata->regs) {
1490 /* Already mapped by setup code */
1491 port->membase = pdata->regs;
1493 port->flags |= UPF_IOREMAP;
1494 port->membase = NULL;
1497 /* for console, the clock could already be configured */
1498 if (!atmel_port->clk) {
1499 atmel_port->clk = clk_get(&pdev->dev, "usart");
1500 clk_enable(atmel_port->clk);
1501 port->uartclk = clk_get_rate(atmel_port->clk);
1502 clk_disable(atmel_port->clk);
1503 /* only enable clock when USART is in use */
1506 /* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
1507 if (atmel_port->rs485.flags & SER_RS485_ENABLED)
1508 atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
1509 else if (atmel_use_dma_tx(port)) {
1510 port->fifosize = PDC_BUFFER_SIZE;
1511 atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE;
1513 atmel_port->tx_done_mask = ATMEL_US_TXRDY;
1518 * Register board-specific modem-control line handlers.
1520 void __init atmel_register_uart_fns(struct atmel_port_fns *fns)
1523 atmel_pops.enable_ms = fns->enable_ms;
1525 atmel_pops.get_mctrl = fns->get_mctrl;
1527 atmel_pops.set_mctrl = fns->set_mctrl;
1528 atmel_open_hook = fns->open;
1529 atmel_close_hook = fns->close;
1530 atmel_pops.pm = fns->pm;
1531 atmel_pops.set_wake = fns->set_wake;
1534 #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
1535 static void atmel_console_putchar(struct uart_port *port, int ch)
1537 while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
1539 UART_PUT_CHAR(port, ch);
1543 * Interrupts are disabled on entering
1545 static void atmel_console_write(struct console *co, const char *s, u_int count)
1547 struct uart_port *port = &atmel_ports[co->index].uart;
1548 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1549 unsigned int status, imr;
1550 unsigned int pdc_tx;
1553 * First, save IMR and then disable interrupts
1555 imr = UART_GET_IMR(port);
1556 UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask);
1558 /* Store PDC transmit status and disable it */
1559 pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN;
1560 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
1562 uart_console_write(port, s, count, atmel_console_putchar);
1565 * Finally, wait for transmitter to become empty
1569 status = UART_GET_CSR(port);
1570 } while (!(status & ATMEL_US_TXRDY));
1572 /* Restore PDC transmit status */
1574 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
1576 /* set interrupts back the way they were */
1577 UART_PUT_IER(port, imr);
1581 * If the port was already initialised (eg, by a boot loader),
1582 * try to determine the current setup.
1584 static void __init atmel_console_get_options(struct uart_port *port, int *baud,
1585 int *parity, int *bits)
1587 unsigned int mr, quot;
1590 * If the baud rate generator isn't running, the port wasn't
1591 * initialized by the boot loader.
1593 quot = UART_GET_BRGR(port) & ATMEL_US_CD;
1597 mr = UART_GET_MR(port) & ATMEL_US_CHRL;
1598 if (mr == ATMEL_US_CHRL_8)
1603 mr = UART_GET_MR(port) & ATMEL_US_PAR;
1604 if (mr == ATMEL_US_PAR_EVEN)
1606 else if (mr == ATMEL_US_PAR_ODD)
1610 * The serial core only rounds down when matching this to a
1611 * supported baud rate. Make sure we don't end up slightly
1612 * lower than one of those, as it would make us fall through
1613 * to a much lower baud rate than we really want.
1615 *baud = port->uartclk / (16 * (quot - 1));
1618 static int __init atmel_console_setup(struct console *co, char *options)
1620 struct uart_port *port = &atmel_ports[co->index].uart;
1626 if (port->membase == NULL) {
1627 /* Port not initialized yet - delay setup */
1631 clk_enable(atmel_ports[co->index].clk);
1633 UART_PUT_IDR(port, -1);
1634 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1635 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1638 uart_parse_options(options, &baud, &parity, &bits, &flow);
1640 atmel_console_get_options(port, &baud, &parity, &bits);
1642 return uart_set_options(port, co, baud, parity, bits, flow);
1645 static struct uart_driver atmel_uart;
1647 static struct console atmel_console = {
1648 .name = ATMEL_DEVICENAME,
1649 .write = atmel_console_write,
1650 .device = uart_console_device,
1651 .setup = atmel_console_setup,
1652 .flags = CON_PRINTBUFFER,
1654 .data = &atmel_uart,
1657 #define ATMEL_CONSOLE_DEVICE (&atmel_console)
1660 * Early console initialization (before VM subsystem initialized).
1662 static int __init atmel_console_init(void)
1664 if (atmel_default_console_device) {
1665 struct atmel_uart_data *pdata =
1666 atmel_default_console_device->dev.platform_data;
1667 int id = pdata->num;
1668 struct atmel_uart_port *port = &atmel_ports[id];
1670 port->backup_imr = 0;
1671 port->uart.line = id;
1673 add_preferred_console(ATMEL_DEVICENAME, id, NULL);
1674 atmel_init_port(port, atmel_default_console_device);
1675 register_console(&atmel_console);
1681 console_initcall(atmel_console_init);
1684 * Late console initialization.
1686 static int __init atmel_late_console_init(void)
1688 if (atmel_default_console_device
1689 && !(atmel_console.flags & CON_ENABLED))
1690 register_console(&atmel_console);
1695 core_initcall(atmel_late_console_init);
1697 static inline bool atmel_is_console_port(struct uart_port *port)
1699 return port->cons && port->cons->index == port->line;
1703 #define ATMEL_CONSOLE_DEVICE NULL
1705 static inline bool atmel_is_console_port(struct uart_port *port)
1711 static struct uart_driver atmel_uart = {
1712 .owner = THIS_MODULE,
1713 .driver_name = "atmel_serial",
1714 .dev_name = ATMEL_DEVICENAME,
1715 .major = SERIAL_ATMEL_MAJOR,
1716 .minor = MINOR_START,
1717 .nr = ATMEL_MAX_UART,
1718 .cons = ATMEL_CONSOLE_DEVICE,
1722 static bool atmel_serial_clk_will_stop(void)
1724 #ifdef CONFIG_ARCH_AT91
1725 return at91_suspend_entering_slow_clock();
1731 static int atmel_serial_suspend(struct platform_device *pdev,
1734 struct uart_port *port = platform_get_drvdata(pdev);
1735 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1737 if (atmel_is_console_port(port) && console_suspend_enabled) {
1738 /* Drain the TX shifter */
1739 while (!(UART_GET_CSR(port) & ATMEL_US_TXEMPTY))
1743 /* we can not wake up if we're running on slow clock */
1744 atmel_port->may_wakeup = device_may_wakeup(&pdev->dev);
1745 if (atmel_serial_clk_will_stop())
1746 device_set_wakeup_enable(&pdev->dev, 0);
1748 uart_suspend_port(&atmel_uart, port);
1753 static int atmel_serial_resume(struct platform_device *pdev)
1755 struct uart_port *port = platform_get_drvdata(pdev);
1756 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1758 uart_resume_port(&atmel_uart, port);
1759 device_set_wakeup_enable(&pdev->dev, atmel_port->may_wakeup);
1764 #define atmel_serial_suspend NULL
1765 #define atmel_serial_resume NULL
1768 static int __devinit atmel_serial_probe(struct platform_device *pdev)
1770 struct atmel_uart_port *port;
1771 struct device_node *np = pdev->dev.of_node;
1772 struct atmel_uart_data *pdata = pdev->dev.platform_data;
1776 BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
1779 ret = of_alias_get_id(np, "serial");
1785 /* port id not found in platform data nor device-tree aliases:
1786 * auto-enumerate it */
1787 ret = find_first_zero_bit(&atmel_ports_in_use,
1788 sizeof(atmel_ports_in_use));
1790 if (ret > ATMEL_MAX_UART) {
1795 if (test_and_set_bit(ret, &atmel_ports_in_use)) {
1796 /* port already in use */
1801 port = &atmel_ports[ret];
1802 port->backup_imr = 0;
1803 port->uart.line = ret;
1805 atmel_init_port(port, pdev);
1807 if (!atmel_use_dma_rx(&port->uart)) {
1809 data = kmalloc(sizeof(struct atmel_uart_char)
1810 * ATMEL_SERIAL_RINGSIZE, GFP_KERNEL);
1812 goto err_alloc_ring;
1813 port->rx_ring.buf = data;
1816 ret = uart_add_one_port(&atmel_uart, &port->uart);
1820 #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
1821 if (atmel_is_console_port(&port->uart)
1822 && ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) {
1824 * The serial core enabled the clock for us, so undo
1825 * the clk_enable() in atmel_console_setup()
1827 clk_disable(port->clk);
1831 device_init_wakeup(&pdev->dev, 1);
1832 platform_set_drvdata(pdev, port);
1834 if (port->rs485.flags & SER_RS485_ENABLED) {
1835 UART_PUT_MR(&port->uart, ATMEL_US_USMODE_NORMAL);
1836 UART_PUT_CR(&port->uart, ATMEL_US_RTSEN);
1842 kfree(port->rx_ring.buf);
1843 port->rx_ring.buf = NULL;
1845 if (!atmel_is_console_port(&port->uart)) {
1853 static int __devexit atmel_serial_remove(struct platform_device *pdev)
1855 struct uart_port *port = platform_get_drvdata(pdev);
1856 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1859 device_init_wakeup(&pdev->dev, 0);
1860 platform_set_drvdata(pdev, NULL);
1862 ret = uart_remove_one_port(&atmel_uart, port);
1864 tasklet_kill(&atmel_port->tasklet);
1865 kfree(atmel_port->rx_ring.buf);
1867 /* "port" is allocated statically, so we shouldn't free it */
1869 clear_bit(port->line, &atmel_ports_in_use);
1871 clk_put(atmel_port->clk);
1876 static struct platform_driver atmel_serial_driver = {
1877 .probe = atmel_serial_probe,
1878 .remove = __devexit_p(atmel_serial_remove),
1879 .suspend = atmel_serial_suspend,
1880 .resume = atmel_serial_resume,
1882 .name = "atmel_usart",
1883 .owner = THIS_MODULE,
1884 .of_match_table = of_match_ptr(atmel_serial_dt_ids),
1888 static int __init atmel_serial_init(void)
1892 ret = uart_register_driver(&atmel_uart);
1896 ret = platform_driver_register(&atmel_serial_driver);
1898 uart_unregister_driver(&atmel_uart);
1903 static void __exit atmel_serial_exit(void)
1905 platform_driver_unregister(&atmel_serial_driver);
1906 uart_unregister_driver(&atmel_uart);
1909 module_init(atmel_serial_init);
1910 module_exit(atmel_serial_exit);
1912 MODULE_AUTHOR("Rick Bronson");
1913 MODULE_DESCRIPTION("Atmel AT91 / AT32 serial port driver");
1914 MODULE_LICENSE("GPL");
1915 MODULE_ALIAS("platform:atmel_usart");