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>
45 #include <asm/ioctls.h>
47 #include <asm/mach/serial_at91.h>
48 #include <mach/board.h>
55 #define PDC_BUFFER_SIZE 512
56 /* Revisit: We should calculate this based on the actual port settings */
57 #define PDC_RX_TIMEOUT (3 * 10) /* 3 bytes */
59 #if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
63 #include <linux/serial_core.h>
65 static void atmel_start_rx(struct uart_port *port);
66 static void atmel_stop_rx(struct uart_port *port);
68 #ifdef CONFIG_SERIAL_ATMEL_TTYAT
70 /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we
71 * should coexist with the 8250 driver, such as if we have an external 16C550
73 #define SERIAL_ATMEL_MAJOR 204
74 #define MINOR_START 154
75 #define ATMEL_DEVICENAME "ttyAT"
79 /* Use device name ttyS, major 4, minor 64-68. This is the usual serial port
80 * name, but it is legally reserved for the 8250 driver. */
81 #define SERIAL_ATMEL_MAJOR TTY_MAJOR
82 #define MINOR_START 64
83 #define ATMEL_DEVICENAME "ttyS"
87 #define ATMEL_ISR_PASS_LIMIT 256
89 /* UART registers. CR is write-only, hence no GET macro */
90 #define UART_PUT_CR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_CR)
91 #define UART_GET_MR(port) __raw_readl((port)->membase + ATMEL_US_MR)
92 #define UART_PUT_MR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_MR)
93 #define UART_PUT_IER(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IER)
94 #define UART_PUT_IDR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IDR)
95 #define UART_GET_IMR(port) __raw_readl((port)->membase + ATMEL_US_IMR)
96 #define UART_GET_CSR(port) __raw_readl((port)->membase + ATMEL_US_CSR)
97 #define UART_GET_CHAR(port) __raw_readl((port)->membase + ATMEL_US_RHR)
98 #define UART_PUT_CHAR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_THR)
99 #define UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR)
100 #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_BRGR)
101 #define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_RTOR)
102 #define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase + ATMEL_US_TTGR)
105 #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR)
106 #define UART_GET_PTSR(port) __raw_readl((port)->membase + ATMEL_PDC_PTSR)
108 #define UART_PUT_RPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RPR)
109 #define UART_GET_RPR(port) __raw_readl((port)->membase + ATMEL_PDC_RPR)
110 #define UART_PUT_RCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RCR)
111 #define UART_PUT_RNPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNPR)
112 #define UART_PUT_RNCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNCR)
114 #define UART_PUT_TPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TPR)
115 #define UART_PUT_TCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TCR)
116 #define UART_GET_TCR(port) __raw_readl((port)->membase + ATMEL_PDC_TCR)
118 static int (*atmel_open_hook)(struct uart_port *);
119 static void (*atmel_close_hook)(struct uart_port *);
121 struct atmel_dma_buffer {
124 unsigned int dma_size;
128 struct atmel_uart_char {
133 #define ATMEL_SERIAL_RINGSIZE 1024
136 * We wrap our port structure around the generic uart_port.
138 struct atmel_uart_port {
139 struct uart_port uart; /* uart */
140 struct clk *clk; /* uart clock */
141 int may_wakeup; /* cached value of device_may_wakeup for times we need to disable it */
142 u32 backup_imr; /* IMR saved during suspend */
143 int break_active; /* break being received */
145 short use_dma_rx; /* enable PDC receiver */
146 short pdc_rx_idx; /* current PDC RX buffer */
147 struct atmel_dma_buffer pdc_rx[2]; /* PDC receier */
149 short use_dma_tx; /* enable PDC transmitter */
150 struct atmel_dma_buffer pdc_tx; /* PDC transmitter */
152 struct tasklet_struct tasklet;
153 unsigned int irq_status;
154 unsigned int irq_status_prev;
156 struct circ_buf rx_ring;
158 struct serial_rs485 rs485; /* rs485 settings */
159 unsigned int tx_done_mask;
162 static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
163 static unsigned long atmel_ports_in_use;
166 static struct console atmel_console;
169 #if defined(CONFIG_OF)
170 static const struct of_device_id atmel_serial_dt_ids[] = {
171 { .compatible = "atmel,at91rm9200-usart" },
172 { .compatible = "atmel,at91sam9260-usart" },
176 MODULE_DEVICE_TABLE(of, atmel_serial_dt_ids);
179 static inline struct atmel_uart_port *
180 to_atmel_uart_port(struct uart_port *uart)
182 return container_of(uart, struct atmel_uart_port, uart);
185 #ifdef CONFIG_SERIAL_ATMEL_PDC
186 static bool atmel_use_dma_rx(struct uart_port *port)
188 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
190 return atmel_port->use_dma_rx;
193 static bool atmel_use_dma_tx(struct uart_port *port)
195 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
197 return atmel_port->use_dma_tx;
200 static bool atmel_use_dma_rx(struct uart_port *port)
205 static bool atmel_use_dma_tx(struct uart_port *port)
211 /* Enable or disable the rs485 support */
212 void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
214 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
218 spin_lock_irqsave(&port->lock, flags);
220 /* Disable interrupts */
221 UART_PUT_IDR(port, atmel_port->tx_done_mask);
223 mode = UART_GET_MR(port);
225 /* Resetting serial mode to RS232 (0x0) */
226 mode &= ~ATMEL_US_USMODE;
228 atmel_port->rs485 = *rs485conf;
230 if (rs485conf->flags & SER_RS485_ENABLED) {
231 dev_dbg(port->dev, "Setting UART to RS485\n");
232 atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
233 if ((rs485conf->delay_rts_after_send) > 0)
234 UART_PUT_TTGR(port, rs485conf->delay_rts_after_send);
235 mode |= ATMEL_US_USMODE_RS485;
237 dev_dbg(port->dev, "Setting UART to RS232\n");
238 if (atmel_use_dma_tx(port))
239 atmel_port->tx_done_mask = ATMEL_US_ENDTX |
242 atmel_port->tx_done_mask = ATMEL_US_TXRDY;
244 UART_PUT_MR(port, mode);
246 /* Enable interrupts */
247 UART_PUT_IER(port, atmel_port->tx_done_mask);
249 spin_unlock_irqrestore(&port->lock, flags);
254 * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
256 static u_int atmel_tx_empty(struct uart_port *port)
258 return (UART_GET_CSR(port) & ATMEL_US_TXEMPTY) ? TIOCSER_TEMT : 0;
262 * Set state of the modem control output lines
264 static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
266 unsigned int control = 0;
268 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
270 #ifdef CONFIG_ARCH_AT91RM9200
271 if (cpu_is_at91rm9200()) {
273 * AT91RM9200 Errata #39: RTS0 is not internally connected
274 * to PA21. We need to drive the pin manually.
276 if (port->mapbase == AT91RM9200_BASE_US0) {
277 if (mctrl & TIOCM_RTS)
278 at91_set_gpio_value(AT91_PIN_PA21, 0);
280 at91_set_gpio_value(AT91_PIN_PA21, 1);
285 if (mctrl & TIOCM_RTS)
286 control |= ATMEL_US_RTSEN;
288 control |= ATMEL_US_RTSDIS;
290 if (mctrl & TIOCM_DTR)
291 control |= ATMEL_US_DTREN;
293 control |= ATMEL_US_DTRDIS;
295 UART_PUT_CR(port, control);
297 /* Local loopback mode? */
298 mode = UART_GET_MR(port) & ~ATMEL_US_CHMODE;
299 if (mctrl & TIOCM_LOOP)
300 mode |= ATMEL_US_CHMODE_LOC_LOOP;
302 mode |= ATMEL_US_CHMODE_NORMAL;
304 /* Resetting serial mode to RS232 (0x0) */
305 mode &= ~ATMEL_US_USMODE;
307 if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
308 dev_dbg(port->dev, "Setting UART to RS485\n");
309 if ((atmel_port->rs485.delay_rts_after_send) > 0)
311 atmel_port->rs485.delay_rts_after_send);
312 mode |= ATMEL_US_USMODE_RS485;
314 dev_dbg(port->dev, "Setting UART to RS232\n");
316 UART_PUT_MR(port, mode);
320 * Get state of the modem control input lines
322 static u_int atmel_get_mctrl(struct uart_port *port)
324 unsigned int status, ret = 0;
326 status = UART_GET_CSR(port);
329 * The control signals are active low.
331 if (!(status & ATMEL_US_DCD))
333 if (!(status & ATMEL_US_CTS))
335 if (!(status & ATMEL_US_DSR))
337 if (!(status & ATMEL_US_RI))
346 static void atmel_stop_tx(struct uart_port *port)
348 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
350 if (atmel_use_dma_tx(port)) {
351 /* disable PDC transmit */
352 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
354 /* Disable interrupts */
355 UART_PUT_IDR(port, atmel_port->tx_done_mask);
357 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
358 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
359 atmel_start_rx(port);
363 * Start transmitting.
365 static void atmel_start_tx(struct uart_port *port)
367 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
369 if (atmel_use_dma_tx(port)) {
370 if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN)
371 /* The transmitter is already running. Yes, we
375 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
376 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
379 /* re-enable PDC transmit */
380 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
382 /* Enable interrupts */
383 UART_PUT_IER(port, atmel_port->tx_done_mask);
387 * start receiving - port is in process of being opened.
389 static void atmel_start_rx(struct uart_port *port)
391 UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */
393 UART_PUT_CR(port, ATMEL_US_RXEN);
395 if (atmel_use_dma_rx(port)) {
396 /* enable PDC controller */
397 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
398 port->read_status_mask);
399 UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
401 UART_PUT_IER(port, ATMEL_US_RXRDY);
406 * Stop receiving - port is in process of being closed.
408 static void atmel_stop_rx(struct uart_port *port)
410 UART_PUT_CR(port, ATMEL_US_RXDIS);
412 if (atmel_use_dma_rx(port)) {
413 /* disable PDC receive */
414 UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS);
415 UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
416 port->read_status_mask);
418 UART_PUT_IDR(port, ATMEL_US_RXRDY);
423 * Enable modem status interrupts
425 static void atmel_enable_ms(struct uart_port *port)
427 UART_PUT_IER(port, ATMEL_US_RIIC | ATMEL_US_DSRIC
428 | ATMEL_US_DCDIC | ATMEL_US_CTSIC);
432 * Control the transmission of a break signal
434 static void atmel_break_ctl(struct uart_port *port, int break_state)
436 if (break_state != 0)
437 UART_PUT_CR(port, ATMEL_US_STTBRK); /* start break */
439 UART_PUT_CR(port, ATMEL_US_STPBRK); /* stop break */
443 * Stores the incoming character in the ring buffer
446 atmel_buffer_rx_char(struct uart_port *port, unsigned int status,
449 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
450 struct circ_buf *ring = &atmel_port->rx_ring;
451 struct atmel_uart_char *c;
453 if (!CIRC_SPACE(ring->head, ring->tail, ATMEL_SERIAL_RINGSIZE))
454 /* Buffer overflow, ignore char */
457 c = &((struct atmel_uart_char *)ring->buf)[ring->head];
461 /* Make sure the character is stored before we update head. */
464 ring->head = (ring->head + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
468 * Deal with parity, framing and overrun errors.
470 static void atmel_pdc_rxerr(struct uart_port *port, unsigned int status)
473 UART_PUT_CR(port, ATMEL_US_RSTSTA);
475 if (status & ATMEL_US_RXBRK) {
476 /* ignore side-effect */
477 status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
480 if (status & ATMEL_US_PARE)
481 port->icount.parity++;
482 if (status & ATMEL_US_FRAME)
483 port->icount.frame++;
484 if (status & ATMEL_US_OVRE)
485 port->icount.overrun++;
489 * Characters received (called from interrupt handler)
491 static void atmel_rx_chars(struct uart_port *port)
493 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
494 unsigned int status, ch;
496 status = UART_GET_CSR(port);
497 while (status & ATMEL_US_RXRDY) {
498 ch = UART_GET_CHAR(port);
501 * note that the error handling code is
502 * out of the main execution path
504 if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
505 | ATMEL_US_OVRE | ATMEL_US_RXBRK)
506 || atmel_port->break_active)) {
509 UART_PUT_CR(port, ATMEL_US_RSTSTA);
511 if (status & ATMEL_US_RXBRK
512 && !atmel_port->break_active) {
513 atmel_port->break_active = 1;
514 UART_PUT_IER(port, ATMEL_US_RXBRK);
517 * This is either the end-of-break
518 * condition or we've received at
519 * least one character without RXBRK
520 * being set. In both cases, the next
521 * RXBRK will indicate start-of-break.
523 UART_PUT_IDR(port, ATMEL_US_RXBRK);
524 status &= ~ATMEL_US_RXBRK;
525 atmel_port->break_active = 0;
529 atmel_buffer_rx_char(port, status, ch);
530 status = UART_GET_CSR(port);
533 tasklet_schedule(&atmel_port->tasklet);
537 * Transmit characters (called from tasklet with TXRDY interrupt
540 static void atmel_tx_chars(struct uart_port *port)
542 struct circ_buf *xmit = &port->state->xmit;
543 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
545 if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) {
546 UART_PUT_CHAR(port, port->x_char);
550 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
553 while (UART_GET_CSR(port) & atmel_port->tx_done_mask) {
554 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
555 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
557 if (uart_circ_empty(xmit))
561 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
562 uart_write_wakeup(port);
564 if (!uart_circ_empty(xmit))
565 /* Enable interrupts */
566 UART_PUT_IER(port, atmel_port->tx_done_mask);
570 * receive interrupt handler.
573 atmel_handle_receive(struct uart_port *port, unsigned int pending)
575 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
577 if (atmel_use_dma_rx(port)) {
579 * PDC receive. Just schedule the tasklet and let it
580 * figure out the details.
582 * TODO: We're not handling error flags correctly at
585 if (pending & (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)) {
586 UART_PUT_IDR(port, (ATMEL_US_ENDRX
587 | ATMEL_US_TIMEOUT));
588 tasklet_schedule(&atmel_port->tasklet);
591 if (pending & (ATMEL_US_RXBRK | ATMEL_US_OVRE |
592 ATMEL_US_FRAME | ATMEL_US_PARE))
593 atmel_pdc_rxerr(port, pending);
596 /* Interrupt receive */
597 if (pending & ATMEL_US_RXRDY)
598 atmel_rx_chars(port);
599 else if (pending & ATMEL_US_RXBRK) {
601 * End of break detected. If it came along with a
602 * character, atmel_rx_chars will handle it.
604 UART_PUT_CR(port, ATMEL_US_RSTSTA);
605 UART_PUT_IDR(port, ATMEL_US_RXBRK);
606 atmel_port->break_active = 0;
611 * transmit interrupt handler. (Transmit is IRQF_NODELAY safe)
614 atmel_handle_transmit(struct uart_port *port, unsigned int pending)
616 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
618 if (pending & atmel_port->tx_done_mask) {
619 /* Either PDC or interrupt transmission */
620 UART_PUT_IDR(port, atmel_port->tx_done_mask);
621 tasklet_schedule(&atmel_port->tasklet);
626 * status flags interrupt handler.
629 atmel_handle_status(struct uart_port *port, unsigned int pending,
632 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
634 if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC
636 atmel_port->irq_status = status;
637 tasklet_schedule(&atmel_port->tasklet);
644 static irqreturn_t atmel_interrupt(int irq, void *dev_id)
646 struct uart_port *port = dev_id;
647 unsigned int status, pending, pass_counter = 0;
650 status = UART_GET_CSR(port);
651 pending = status & UART_GET_IMR(port);
655 atmel_handle_receive(port, pending);
656 atmel_handle_status(port, pending, status);
657 atmel_handle_transmit(port, pending);
658 } while (pass_counter++ < ATMEL_ISR_PASS_LIMIT);
660 return pass_counter ? IRQ_HANDLED : IRQ_NONE;
664 * Called from tasklet with ENDTX and TXBUFE interrupts disabled.
666 static void atmel_tx_dma(struct uart_port *port)
668 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
669 struct circ_buf *xmit = &port->state->xmit;
670 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
673 /* nothing left to transmit? */
674 if (UART_GET_TCR(port))
677 xmit->tail += pdc->ofs;
678 xmit->tail &= UART_XMIT_SIZE - 1;
680 port->icount.tx += pdc->ofs;
683 /* more to transmit - setup next transfer */
685 /* disable PDC transmit */
686 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
688 if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
689 dma_sync_single_for_device(port->dev,
694 count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
697 UART_PUT_TPR(port, pdc->dma_addr + xmit->tail);
698 UART_PUT_TCR(port, count);
699 /* re-enable PDC transmit */
700 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
701 /* Enable interrupts */
702 UART_PUT_IER(port, atmel_port->tx_done_mask);
704 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
705 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX)) {
706 /* DMA done, stop TX, start RX for RS485 */
707 atmel_start_rx(port);
711 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
712 uart_write_wakeup(port);
715 static void atmel_rx_from_ring(struct uart_port *port)
717 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
718 struct circ_buf *ring = &atmel_port->rx_ring;
722 while (ring->head != ring->tail) {
723 struct atmel_uart_char c;
725 /* Make sure c is loaded after head. */
728 c = ((struct atmel_uart_char *)ring->buf)[ring->tail];
730 ring->tail = (ring->tail + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
737 * note that the error handling code is
738 * out of the main execution path
740 if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
741 | ATMEL_US_OVRE | ATMEL_US_RXBRK))) {
742 if (status & ATMEL_US_RXBRK) {
743 /* ignore side-effect */
744 status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
747 if (uart_handle_break(port))
750 if (status & ATMEL_US_PARE)
751 port->icount.parity++;
752 if (status & ATMEL_US_FRAME)
753 port->icount.frame++;
754 if (status & ATMEL_US_OVRE)
755 port->icount.overrun++;
757 status &= port->read_status_mask;
759 if (status & ATMEL_US_RXBRK)
761 else if (status & ATMEL_US_PARE)
763 else if (status & ATMEL_US_FRAME)
768 if (uart_handle_sysrq_char(port, c.ch))
771 uart_insert_char(port, status, ATMEL_US_OVRE, c.ch, flg);
775 * Drop the lock here since it might end up calling
776 * uart_start(), which takes the lock.
778 spin_unlock(&port->lock);
779 tty_flip_buffer_push(port->state->port.tty);
780 spin_lock(&port->lock);
783 static void atmel_rx_from_dma(struct uart_port *port)
785 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
786 struct tty_struct *tty = port->state->port.tty;
787 struct atmel_dma_buffer *pdc;
788 int rx_idx = atmel_port->pdc_rx_idx;
794 /* Reset the UART timeout early so that we don't miss one */
795 UART_PUT_CR(port, ATMEL_US_STTTO);
797 pdc = &atmel_port->pdc_rx[rx_idx];
798 head = UART_GET_RPR(port) - pdc->dma_addr;
801 /* If the PDC has switched buffers, RPR won't contain
802 * any address within the current buffer. Since head
803 * is unsigned, we just need a one-way comparison to
806 * In this case, we just need to consume the entire
807 * buffer and resubmit it for DMA. This will clear the
808 * ENDRX bit as well, so that we can safely re-enable
809 * all interrupts below.
811 head = min(head, pdc->dma_size);
813 if (likely(head != tail)) {
814 dma_sync_single_for_cpu(port->dev, pdc->dma_addr,
815 pdc->dma_size, DMA_FROM_DEVICE);
818 * head will only wrap around when we recycle
819 * the DMA buffer, and when that happens, we
820 * explicitly set tail to 0. So head will
821 * always be greater than tail.
825 tty_insert_flip_string(tty, pdc->buf + pdc->ofs, count);
827 dma_sync_single_for_device(port->dev, pdc->dma_addr,
828 pdc->dma_size, DMA_FROM_DEVICE);
830 port->icount.rx += count;
835 * If the current buffer is full, we need to check if
836 * the next one contains any additional data.
838 if (head >= pdc->dma_size) {
840 UART_PUT_RNPR(port, pdc->dma_addr);
841 UART_PUT_RNCR(port, pdc->dma_size);
844 atmel_port->pdc_rx_idx = rx_idx;
846 } while (head >= pdc->dma_size);
849 * Drop the lock here since it might end up calling
850 * uart_start(), which takes the lock.
852 spin_unlock(&port->lock);
853 tty_flip_buffer_push(tty);
854 spin_lock(&port->lock);
856 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
860 * tasklet handling tty stuff outside the interrupt handler.
862 static void atmel_tasklet_func(unsigned long data)
864 struct uart_port *port = (struct uart_port *)data;
865 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
867 unsigned int status_change;
869 /* The interrupt handler does not take the lock */
870 spin_lock(&port->lock);
872 if (atmel_use_dma_tx(port))
875 atmel_tx_chars(port);
877 status = atmel_port->irq_status;
878 status_change = status ^ atmel_port->irq_status_prev;
880 if (status_change & (ATMEL_US_RI | ATMEL_US_DSR
881 | ATMEL_US_DCD | ATMEL_US_CTS)) {
882 /* TODO: All reads to CSR will clear these interrupts! */
883 if (status_change & ATMEL_US_RI)
885 if (status_change & ATMEL_US_DSR)
887 if (status_change & ATMEL_US_DCD)
888 uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
889 if (status_change & ATMEL_US_CTS)
890 uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
892 wake_up_interruptible(&port->state->port.delta_msr_wait);
894 atmel_port->irq_status_prev = status;
897 if (atmel_use_dma_rx(port))
898 atmel_rx_from_dma(port);
900 atmel_rx_from_ring(port);
902 spin_unlock(&port->lock);
906 * Perform initialization and enable port for reception
908 static int atmel_startup(struct uart_port *port)
910 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
911 struct tty_struct *tty = port->state->port.tty;
915 * Ensure that no interrupts are enabled otherwise when
916 * request_irq() is called we could get stuck trying to
917 * handle an unexpected interrupt
919 UART_PUT_IDR(port, -1);
924 retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED,
925 tty ? tty->name : "atmel_serial", port);
927 printk("atmel_serial: atmel_startup - Can't get irq\n");
932 * Initialize DMA (if necessary)
934 if (atmel_use_dma_rx(port)) {
937 for (i = 0; i < 2; i++) {
938 struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
940 pdc->buf = kmalloc(PDC_BUFFER_SIZE, GFP_KERNEL);
941 if (pdc->buf == NULL) {
943 dma_unmap_single(port->dev,
944 atmel_port->pdc_rx[0].dma_addr,
947 kfree(atmel_port->pdc_rx[0].buf);
949 free_irq(port->irq, port);
952 pdc->dma_addr = dma_map_single(port->dev,
956 pdc->dma_size = PDC_BUFFER_SIZE;
960 atmel_port->pdc_rx_idx = 0;
962 UART_PUT_RPR(port, atmel_port->pdc_rx[0].dma_addr);
963 UART_PUT_RCR(port, PDC_BUFFER_SIZE);
965 UART_PUT_RNPR(port, atmel_port->pdc_rx[1].dma_addr);
966 UART_PUT_RNCR(port, PDC_BUFFER_SIZE);
968 if (atmel_use_dma_tx(port)) {
969 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
970 struct circ_buf *xmit = &port->state->xmit;
972 pdc->buf = xmit->buf;
973 pdc->dma_addr = dma_map_single(port->dev,
977 pdc->dma_size = UART_XMIT_SIZE;
982 * If there is a specific "open" function (to register
983 * control line interrupts)
985 if (atmel_open_hook) {
986 retval = atmel_open_hook(port);
988 free_irq(port->irq, port);
993 /* Save current CSR for comparison in atmel_tasklet_func() */
994 atmel_port->irq_status_prev = UART_GET_CSR(port);
995 atmel_port->irq_status = atmel_port->irq_status_prev;
998 * Finally, enable the serial port
1000 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1001 /* enable xmit & rcvr */
1002 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1004 if (atmel_use_dma_rx(port)) {
1005 /* set UART timeout */
1006 UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
1007 UART_PUT_CR(port, ATMEL_US_STTTO);
1009 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
1010 /* enable PDC controller */
1011 UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
1013 /* enable receive only */
1014 UART_PUT_IER(port, ATMEL_US_RXRDY);
1023 static void atmel_shutdown(struct uart_port *port)
1025 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1027 * Ensure everything is stopped.
1029 atmel_stop_rx(port);
1030 atmel_stop_tx(port);
1033 * Shut-down the DMA.
1035 if (atmel_use_dma_rx(port)) {
1038 for (i = 0; i < 2; i++) {
1039 struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
1041 dma_unmap_single(port->dev,
1048 if (atmel_use_dma_tx(port)) {
1049 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
1051 dma_unmap_single(port->dev,
1058 * Disable all interrupts, port and break condition.
1060 UART_PUT_CR(port, ATMEL_US_RSTSTA);
1061 UART_PUT_IDR(port, -1);
1064 * Free the interrupt
1066 free_irq(port->irq, port);
1069 * If there is a specific "close" function (to unregister
1070 * control line interrupts)
1072 if (atmel_close_hook)
1073 atmel_close_hook(port);
1077 * Flush any TX data submitted for DMA. Called when the TX circular
1080 static void atmel_flush_buffer(struct uart_port *port)
1082 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1084 if (atmel_use_dma_tx(port)) {
1085 UART_PUT_TCR(port, 0);
1086 atmel_port->pdc_tx.ofs = 0;
1091 * Power / Clock management.
1093 static void atmel_serial_pm(struct uart_port *port, unsigned int state,
1094 unsigned int oldstate)
1096 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1101 * Enable the peripheral clock for this serial port.
1102 * This is called on uart_open() or a resume event.
1104 clk_enable(atmel_port->clk);
1106 /* re-enable interrupts if we disabled some on suspend */
1107 UART_PUT_IER(port, atmel_port->backup_imr);
1110 /* Back up the interrupt mask and disable all interrupts */
1111 atmel_port->backup_imr = UART_GET_IMR(port);
1112 UART_PUT_IDR(port, -1);
1115 * Disable the peripheral clock for this serial port.
1116 * This is called on uart_close() or a suspend event.
1118 clk_disable(atmel_port->clk);
1121 printk(KERN_ERR "atmel_serial: unknown pm %d\n", state);
1126 * Change the port parameters
1128 static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
1129 struct ktermios *old)
1131 unsigned long flags;
1132 unsigned int mode, imr, quot, baud;
1133 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1135 /* Get current mode register */
1136 mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL
1137 | ATMEL_US_NBSTOP | ATMEL_US_PAR
1140 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
1141 quot = uart_get_divisor(port, baud);
1143 if (quot > 65535) { /* BRGR is 16-bit, so switch to slower clock */
1145 mode |= ATMEL_US_USCLKS_MCK_DIV8;
1149 switch (termios->c_cflag & CSIZE) {
1151 mode |= ATMEL_US_CHRL_5;
1154 mode |= ATMEL_US_CHRL_6;
1157 mode |= ATMEL_US_CHRL_7;
1160 mode |= ATMEL_US_CHRL_8;
1165 if (termios->c_cflag & CSTOPB)
1166 mode |= ATMEL_US_NBSTOP_2;
1169 if (termios->c_cflag & PARENB) {
1170 /* Mark or Space parity */
1171 if (termios->c_cflag & CMSPAR) {
1172 if (termios->c_cflag & PARODD)
1173 mode |= ATMEL_US_PAR_MARK;
1175 mode |= ATMEL_US_PAR_SPACE;
1176 } else if (termios->c_cflag & PARODD)
1177 mode |= ATMEL_US_PAR_ODD;
1179 mode |= ATMEL_US_PAR_EVEN;
1181 mode |= ATMEL_US_PAR_NONE;
1183 /* hardware handshake (RTS/CTS) */
1184 if (termios->c_cflag & CRTSCTS)
1185 mode |= ATMEL_US_USMODE_HWHS;
1187 mode |= ATMEL_US_USMODE_NORMAL;
1189 spin_lock_irqsave(&port->lock, flags);
1191 port->read_status_mask = ATMEL_US_OVRE;
1192 if (termios->c_iflag & INPCK)
1193 port->read_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
1194 if (termios->c_iflag & (BRKINT | PARMRK))
1195 port->read_status_mask |= ATMEL_US_RXBRK;
1197 if (atmel_use_dma_rx(port))
1198 /* need to enable error interrupts */
1199 UART_PUT_IER(port, port->read_status_mask);
1202 * Characters to ignore
1204 port->ignore_status_mask = 0;
1205 if (termios->c_iflag & IGNPAR)
1206 port->ignore_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
1207 if (termios->c_iflag & IGNBRK) {
1208 port->ignore_status_mask |= ATMEL_US_RXBRK;
1210 * If we're ignoring parity and break indicators,
1211 * ignore overruns too (for real raw support).
1213 if (termios->c_iflag & IGNPAR)
1214 port->ignore_status_mask |= ATMEL_US_OVRE;
1216 /* TODO: Ignore all characters if CREAD is set.*/
1218 /* update the per-port timeout */
1219 uart_update_timeout(port, termios->c_cflag, baud);
1222 * save/disable interrupts. The tty layer will ensure that the
1223 * transmitter is empty if requested by the caller, so there's
1224 * no need to wait for it here.
1226 imr = UART_GET_IMR(port);
1227 UART_PUT_IDR(port, -1);
1229 /* disable receiver and transmitter */
1230 UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
1232 /* Resetting serial mode to RS232 (0x0) */
1233 mode &= ~ATMEL_US_USMODE;
1235 if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
1236 dev_dbg(port->dev, "Setting UART to RS485\n");
1237 if ((atmel_port->rs485.delay_rts_after_send) > 0)
1239 atmel_port->rs485.delay_rts_after_send);
1240 mode |= ATMEL_US_USMODE_RS485;
1242 dev_dbg(port->dev, "Setting UART to RS232\n");
1245 /* set the parity, stop bits and data size */
1246 UART_PUT_MR(port, mode);
1248 /* set the baud rate */
1249 UART_PUT_BRGR(port, quot);
1250 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1251 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1253 /* restore interrupts */
1254 UART_PUT_IER(port, imr);
1256 /* CTS flow-control and modem-status interrupts */
1257 if (UART_ENABLE_MS(port, termios->c_cflag))
1258 port->ops->enable_ms(port);
1260 spin_unlock_irqrestore(&port->lock, flags);
1263 static void atmel_set_ldisc(struct uart_port *port, int new)
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 struct platform_device *atmel_default_console_device; /* the serial console device */
1536 #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
1537 static void atmel_console_putchar(struct uart_port *port, int ch)
1539 while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
1541 UART_PUT_CHAR(port, ch);
1545 * Interrupts are disabled on entering
1547 static void atmel_console_write(struct console *co, const char *s, u_int count)
1549 struct uart_port *port = &atmel_ports[co->index].uart;
1550 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1551 unsigned int status, imr;
1552 unsigned int pdc_tx;
1555 * First, save IMR and then disable interrupts
1557 imr = UART_GET_IMR(port);
1558 UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask);
1560 /* Store PDC transmit status and disable it */
1561 pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN;
1562 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
1564 uart_console_write(port, s, count, atmel_console_putchar);
1567 * Finally, wait for transmitter to become empty
1571 status = UART_GET_CSR(port);
1572 } while (!(status & ATMEL_US_TXRDY));
1574 /* Restore PDC transmit status */
1576 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
1578 /* set interrupts back the way they were */
1579 UART_PUT_IER(port, imr);
1583 * If the port was already initialised (eg, by a boot loader),
1584 * try to determine the current setup.
1586 static void __init atmel_console_get_options(struct uart_port *port, int *baud,
1587 int *parity, int *bits)
1589 unsigned int mr, quot;
1592 * If the baud rate generator isn't running, the port wasn't
1593 * initialized by the boot loader.
1595 quot = UART_GET_BRGR(port) & ATMEL_US_CD;
1599 mr = UART_GET_MR(port) & ATMEL_US_CHRL;
1600 if (mr == ATMEL_US_CHRL_8)
1605 mr = UART_GET_MR(port) & ATMEL_US_PAR;
1606 if (mr == ATMEL_US_PAR_EVEN)
1608 else if (mr == ATMEL_US_PAR_ODD)
1612 * The serial core only rounds down when matching this to a
1613 * supported baud rate. Make sure we don't end up slightly
1614 * lower than one of those, as it would make us fall through
1615 * to a much lower baud rate than we really want.
1617 *baud = port->uartclk / (16 * (quot - 1));
1620 static int __init atmel_console_setup(struct console *co, char *options)
1622 struct uart_port *port = &atmel_ports[co->index].uart;
1628 if (port->membase == NULL) {
1629 /* Port not initialized yet - delay setup */
1633 clk_enable(atmel_ports[co->index].clk);
1635 UART_PUT_IDR(port, -1);
1636 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1637 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1640 uart_parse_options(options, &baud, &parity, &bits, &flow);
1642 atmel_console_get_options(port, &baud, &parity, &bits);
1644 return uart_set_options(port, co, baud, parity, bits, flow);
1647 static struct uart_driver atmel_uart;
1649 static struct console atmel_console = {
1650 .name = ATMEL_DEVICENAME,
1651 .write = atmel_console_write,
1652 .device = uart_console_device,
1653 .setup = atmel_console_setup,
1654 .flags = CON_PRINTBUFFER,
1656 .data = &atmel_uart,
1659 #define ATMEL_CONSOLE_DEVICE (&atmel_console)
1662 * Early console initialization (before VM subsystem initialized).
1664 static int __init atmel_console_init(void)
1666 if (atmel_default_console_device) {
1667 struct atmel_uart_data *pdata =
1668 atmel_default_console_device->dev.platform_data;
1669 int id = pdata->num;
1670 struct atmel_uart_port *port = &atmel_ports[id];
1672 port->backup_imr = 0;
1673 port->uart.line = id;
1675 add_preferred_console(ATMEL_DEVICENAME, id, NULL);
1676 atmel_init_port(port, atmel_default_console_device);
1677 register_console(&atmel_console);
1683 console_initcall(atmel_console_init);
1686 * Late console initialization.
1688 static int __init atmel_late_console_init(void)
1690 if (atmel_default_console_device
1691 && !(atmel_console.flags & CON_ENABLED))
1692 register_console(&atmel_console);
1697 core_initcall(atmel_late_console_init);
1699 static inline bool atmel_is_console_port(struct uart_port *port)
1701 return port->cons && port->cons->index == port->line;
1705 #define ATMEL_CONSOLE_DEVICE NULL
1707 static inline bool atmel_is_console_port(struct uart_port *port)
1713 static struct uart_driver atmel_uart = {
1714 .owner = THIS_MODULE,
1715 .driver_name = "atmel_serial",
1716 .dev_name = ATMEL_DEVICENAME,
1717 .major = SERIAL_ATMEL_MAJOR,
1718 .minor = MINOR_START,
1719 .nr = ATMEL_MAX_UART,
1720 .cons = ATMEL_CONSOLE_DEVICE,
1724 static bool atmel_serial_clk_will_stop(void)
1726 #ifdef CONFIG_ARCH_AT91
1727 return at91_suspend_entering_slow_clock();
1733 static int atmel_serial_suspend(struct platform_device *pdev,
1736 struct uart_port *port = platform_get_drvdata(pdev);
1737 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1739 if (atmel_is_console_port(port) && console_suspend_enabled) {
1740 /* Drain the TX shifter */
1741 while (!(UART_GET_CSR(port) & ATMEL_US_TXEMPTY))
1745 /* we can not wake up if we're running on slow clock */
1746 atmel_port->may_wakeup = device_may_wakeup(&pdev->dev);
1747 if (atmel_serial_clk_will_stop())
1748 device_set_wakeup_enable(&pdev->dev, 0);
1750 uart_suspend_port(&atmel_uart, port);
1755 static int atmel_serial_resume(struct platform_device *pdev)
1757 struct uart_port *port = platform_get_drvdata(pdev);
1758 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1760 uart_resume_port(&atmel_uart, port);
1761 device_set_wakeup_enable(&pdev->dev, atmel_port->may_wakeup);
1766 #define atmel_serial_suspend NULL
1767 #define atmel_serial_resume NULL
1770 static int __devinit atmel_serial_probe(struct platform_device *pdev)
1772 struct atmel_uart_port *port;
1773 struct device_node *np = pdev->dev.of_node;
1774 struct atmel_uart_data *pdata = pdev->dev.platform_data;
1777 struct pinctrl *pinctrl;
1779 BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
1782 ret = of_alias_get_id(np, "serial");
1788 /* port id not found in platform data nor device-tree aliases:
1789 * auto-enumerate it */
1790 ret = find_first_zero_bit(&atmel_ports_in_use,
1791 sizeof(atmel_ports_in_use));
1793 if (ret > ATMEL_MAX_UART) {
1798 if (test_and_set_bit(ret, &atmel_ports_in_use)) {
1799 /* port already in use */
1804 port = &atmel_ports[ret];
1805 port->backup_imr = 0;
1806 port->uart.line = ret;
1808 atmel_init_port(port, pdev);
1810 pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
1811 if (IS_ERR(pinctrl)) {
1812 ret = PTR_ERR(pinctrl);
1816 if (!atmel_use_dma_rx(&port->uart)) {
1818 data = kmalloc(sizeof(struct atmel_uart_char)
1819 * ATMEL_SERIAL_RINGSIZE, GFP_KERNEL);
1821 goto err_alloc_ring;
1822 port->rx_ring.buf = data;
1825 ret = uart_add_one_port(&atmel_uart, &port->uart);
1829 #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
1830 if (atmel_is_console_port(&port->uart)
1831 && ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) {
1833 * The serial core enabled the clock for us, so undo
1834 * the clk_enable() in atmel_console_setup()
1836 clk_disable(port->clk);
1840 device_init_wakeup(&pdev->dev, 1);
1841 platform_set_drvdata(pdev, port);
1843 if (port->rs485.flags & SER_RS485_ENABLED) {
1844 UART_PUT_MR(&port->uart, ATMEL_US_USMODE_NORMAL);
1845 UART_PUT_CR(&port->uart, ATMEL_US_RTSEN);
1851 kfree(port->rx_ring.buf);
1852 port->rx_ring.buf = NULL;
1854 if (!atmel_is_console_port(&port->uart)) {
1862 static int __devexit atmel_serial_remove(struct platform_device *pdev)
1864 struct uart_port *port = platform_get_drvdata(pdev);
1865 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1868 device_init_wakeup(&pdev->dev, 0);
1869 platform_set_drvdata(pdev, NULL);
1871 ret = uart_remove_one_port(&atmel_uart, port);
1873 tasklet_kill(&atmel_port->tasklet);
1874 kfree(atmel_port->rx_ring.buf);
1876 /* "port" is allocated statically, so we shouldn't free it */
1878 clear_bit(port->line, &atmel_ports_in_use);
1880 clk_put(atmel_port->clk);
1885 static struct platform_driver atmel_serial_driver = {
1886 .probe = atmel_serial_probe,
1887 .remove = __devexit_p(atmel_serial_remove),
1888 .suspend = atmel_serial_suspend,
1889 .resume = atmel_serial_resume,
1891 .name = "atmel_usart",
1892 .owner = THIS_MODULE,
1893 .of_match_table = of_match_ptr(atmel_serial_dt_ids),
1897 static int __init atmel_serial_init(void)
1901 ret = uart_register_driver(&atmel_uart);
1905 ret = platform_driver_register(&atmel_serial_driver);
1907 uart_unregister_driver(&atmel_uart);
1912 static void __exit atmel_serial_exit(void)
1914 platform_driver_unregister(&atmel_serial_driver);
1915 uart_unregister_driver(&atmel_uart);
1918 module_init(atmel_serial_init);
1919 module_exit(atmel_serial_exit);
1921 MODULE_AUTHOR("Rick Bronson");
1922 MODULE_DESCRIPTION("Atmel AT91 / AT32 serial port driver");
1923 MODULE_LICENSE("GPL");
1924 MODULE_ALIAS("platform:atmel_usart");