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/platform_data/atmel.h>
45 #include <asm/ioctls.h>
52 #define PDC_BUFFER_SIZE 512
53 /* Revisit: We should calculate this based on the actual port settings */
54 #define PDC_RX_TIMEOUT (3 * 10) /* 3 bytes */
56 #if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
60 #include <linux/serial_core.h>
62 static void atmel_start_rx(struct uart_port *port);
63 static void atmel_stop_rx(struct uart_port *port);
65 #ifdef CONFIG_SERIAL_ATMEL_TTYAT
67 /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we
68 * should coexist with the 8250 driver, such as if we have an external 16C550
70 #define SERIAL_ATMEL_MAJOR 204
71 #define MINOR_START 154
72 #define ATMEL_DEVICENAME "ttyAT"
76 /* Use device name ttyS, major 4, minor 64-68. This is the usual serial port
77 * name, but it is legally reserved for the 8250 driver. */
78 #define SERIAL_ATMEL_MAJOR TTY_MAJOR
79 #define MINOR_START 64
80 #define ATMEL_DEVICENAME "ttyS"
84 #define ATMEL_ISR_PASS_LIMIT 256
86 /* UART registers. CR is write-only, hence no GET macro */
87 #define UART_PUT_CR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_CR)
88 #define UART_GET_MR(port) __raw_readl((port)->membase + ATMEL_US_MR)
89 #define UART_PUT_MR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_MR)
90 #define UART_PUT_IER(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IER)
91 #define UART_PUT_IDR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IDR)
92 #define UART_GET_IMR(port) __raw_readl((port)->membase + ATMEL_US_IMR)
93 #define UART_GET_CSR(port) __raw_readl((port)->membase + ATMEL_US_CSR)
94 #define UART_GET_CHAR(port) __raw_readl((port)->membase + ATMEL_US_RHR)
95 #define UART_PUT_CHAR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_THR)
96 #define UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR)
97 #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_BRGR)
98 #define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_RTOR)
99 #define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase + ATMEL_US_TTGR)
102 #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR)
103 #define UART_GET_PTSR(port) __raw_readl((port)->membase + ATMEL_PDC_PTSR)
105 #define UART_PUT_RPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RPR)
106 #define UART_GET_RPR(port) __raw_readl((port)->membase + ATMEL_PDC_RPR)
107 #define UART_PUT_RCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RCR)
108 #define UART_PUT_RNPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNPR)
109 #define UART_PUT_RNCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNCR)
111 #define UART_PUT_TPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TPR)
112 #define UART_PUT_TCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TCR)
113 #define UART_GET_TCR(port) __raw_readl((port)->membase + ATMEL_PDC_TCR)
115 static int (*atmel_open_hook)(struct uart_port *);
116 static void (*atmel_close_hook)(struct uart_port *);
118 struct atmel_dma_buffer {
121 unsigned int dma_size;
125 struct atmel_uart_char {
130 #define ATMEL_SERIAL_RINGSIZE 1024
133 * We wrap our port structure around the generic uart_port.
135 struct atmel_uart_port {
136 struct uart_port uart; /* uart */
137 struct clk *clk; /* uart clock */
138 int may_wakeup; /* cached value of device_may_wakeup for times we need to disable it */
139 u32 backup_imr; /* IMR saved during suspend */
140 int break_active; /* break being received */
142 short use_dma_rx; /* enable PDC receiver */
143 short pdc_rx_idx; /* current PDC RX buffer */
144 struct atmel_dma_buffer pdc_rx[2]; /* PDC receier */
146 short use_dma_tx; /* enable PDC transmitter */
147 struct atmel_dma_buffer pdc_tx; /* PDC transmitter */
149 struct tasklet_struct tasklet;
150 unsigned int irq_status;
151 unsigned int irq_status_prev;
153 struct circ_buf rx_ring;
155 struct serial_rs485 rs485; /* rs485 settings */
156 unsigned int tx_done_mask;
159 static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
160 static DECLARE_BITMAP(atmel_ports_in_use, ATMEL_MAX_UART);
163 static struct console atmel_console;
166 #if defined(CONFIG_OF)
167 static const struct of_device_id atmel_serial_dt_ids[] = {
168 { .compatible = "atmel,at91rm9200-usart" },
169 { .compatible = "atmel,at91sam9260-usart" },
173 MODULE_DEVICE_TABLE(of, atmel_serial_dt_ids);
176 static inline struct atmel_uart_port *
177 to_atmel_uart_port(struct uart_port *uart)
179 return container_of(uart, struct atmel_uart_port, uart);
182 #ifdef CONFIG_SERIAL_ATMEL_PDC
183 static bool atmel_use_dma_rx(struct uart_port *port)
185 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
187 return atmel_port->use_dma_rx;
190 static bool atmel_use_dma_tx(struct uart_port *port)
192 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
194 return atmel_port->use_dma_tx;
197 static bool atmel_use_dma_rx(struct uart_port *port)
202 static bool atmel_use_dma_tx(struct uart_port *port)
208 /* Enable or disable the rs485 support */
209 void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
211 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
215 spin_lock_irqsave(&port->lock, flags);
217 /* Disable interrupts */
218 UART_PUT_IDR(port, atmel_port->tx_done_mask);
220 mode = UART_GET_MR(port);
222 /* Resetting serial mode to RS232 (0x0) */
223 mode &= ~ATMEL_US_USMODE;
225 atmel_port->rs485 = *rs485conf;
227 if (rs485conf->flags & SER_RS485_ENABLED) {
228 dev_dbg(port->dev, "Setting UART to RS485\n");
229 atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
230 if ((rs485conf->delay_rts_after_send) > 0)
231 UART_PUT_TTGR(port, rs485conf->delay_rts_after_send);
232 mode |= ATMEL_US_USMODE_RS485;
234 dev_dbg(port->dev, "Setting UART to RS232\n");
235 if (atmel_use_dma_tx(port))
236 atmel_port->tx_done_mask = ATMEL_US_ENDTX |
239 atmel_port->tx_done_mask = ATMEL_US_TXRDY;
241 UART_PUT_MR(port, mode);
243 /* Enable interrupts */
244 UART_PUT_IER(port, atmel_port->tx_done_mask);
246 spin_unlock_irqrestore(&port->lock, flags);
251 * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
253 static u_int atmel_tx_empty(struct uart_port *port)
255 return (UART_GET_CSR(port) & ATMEL_US_TXEMPTY) ? TIOCSER_TEMT : 0;
259 * Set state of the modem control output lines
261 static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
263 unsigned int control = 0;
265 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
267 #ifdef CONFIG_ARCH_AT91RM9200
268 if (cpu_is_at91rm9200()) {
270 * AT91RM9200 Errata #39: RTS0 is not internally connected
271 * to PA21. We need to drive the pin manually.
273 if (port->mapbase == AT91RM9200_BASE_US0) {
274 if (mctrl & TIOCM_RTS)
275 at91_set_gpio_value(AT91_PIN_PA21, 0);
277 at91_set_gpio_value(AT91_PIN_PA21, 1);
282 if (mctrl & TIOCM_RTS)
283 control |= ATMEL_US_RTSEN;
285 control |= ATMEL_US_RTSDIS;
287 if (mctrl & TIOCM_DTR)
288 control |= ATMEL_US_DTREN;
290 control |= ATMEL_US_DTRDIS;
292 UART_PUT_CR(port, control);
294 /* Local loopback mode? */
295 mode = UART_GET_MR(port) & ~ATMEL_US_CHMODE;
296 if (mctrl & TIOCM_LOOP)
297 mode |= ATMEL_US_CHMODE_LOC_LOOP;
299 mode |= ATMEL_US_CHMODE_NORMAL;
301 /* Resetting serial mode to RS232 (0x0) */
302 mode &= ~ATMEL_US_USMODE;
304 if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
305 dev_dbg(port->dev, "Setting UART to RS485\n");
306 if ((atmel_port->rs485.delay_rts_after_send) > 0)
308 atmel_port->rs485.delay_rts_after_send);
309 mode |= ATMEL_US_USMODE_RS485;
311 dev_dbg(port->dev, "Setting UART to RS232\n");
313 UART_PUT_MR(port, mode);
317 * Get state of the modem control input lines
319 static u_int atmel_get_mctrl(struct uart_port *port)
321 unsigned int status, ret = 0;
323 status = UART_GET_CSR(port);
326 * The control signals are active low.
328 if (!(status & ATMEL_US_DCD))
330 if (!(status & ATMEL_US_CTS))
332 if (!(status & ATMEL_US_DSR))
334 if (!(status & ATMEL_US_RI))
343 static void atmel_stop_tx(struct uart_port *port)
345 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
347 if (atmel_use_dma_tx(port)) {
348 /* disable PDC transmit */
349 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
351 /* Disable interrupts */
352 UART_PUT_IDR(port, atmel_port->tx_done_mask);
354 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
355 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
356 atmel_start_rx(port);
360 * Start transmitting.
362 static void atmel_start_tx(struct uart_port *port)
364 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
366 if (atmel_use_dma_tx(port)) {
367 if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN)
368 /* The transmitter is already running. Yes, we
372 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
373 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX))
376 /* re-enable PDC transmit */
377 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
379 /* Enable interrupts */
380 UART_PUT_IER(port, atmel_port->tx_done_mask);
384 * start receiving - port is in process of being opened.
386 static void atmel_start_rx(struct uart_port *port)
388 UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */
390 UART_PUT_CR(port, ATMEL_US_RXEN);
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 UART_PUT_CR(port, ATMEL_US_RXDIS);
409 if (atmel_use_dma_rx(port)) {
410 /* disable PDC receive */
411 UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS);
412 UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
413 port->read_status_mask);
415 UART_PUT_IDR(port, ATMEL_US_RXRDY);
420 * Enable modem status interrupts
422 static void atmel_enable_ms(struct uart_port *port)
424 UART_PUT_IER(port, ATMEL_US_RIIC | ATMEL_US_DSRIC
425 | ATMEL_US_DCDIC | ATMEL_US_CTSIC);
429 * Control the transmission of a break signal
431 static void atmel_break_ctl(struct uart_port *port, int break_state)
433 if (break_state != 0)
434 UART_PUT_CR(port, ATMEL_US_STTBRK); /* start break */
436 UART_PUT_CR(port, ATMEL_US_STPBRK); /* stop break */
440 * Stores the incoming character in the ring buffer
443 atmel_buffer_rx_char(struct uart_port *port, unsigned int status,
446 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
447 struct circ_buf *ring = &atmel_port->rx_ring;
448 struct atmel_uart_char *c;
450 if (!CIRC_SPACE(ring->head, ring->tail, ATMEL_SERIAL_RINGSIZE))
451 /* Buffer overflow, ignore char */
454 c = &((struct atmel_uart_char *)ring->buf)[ring->head];
458 /* Make sure the character is stored before we update head. */
461 ring->head = (ring->head + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
465 * Deal with parity, framing and overrun errors.
467 static void atmel_pdc_rxerr(struct uart_port *port, unsigned int status)
470 UART_PUT_CR(port, ATMEL_US_RSTSTA);
472 if (status & ATMEL_US_RXBRK) {
473 /* ignore side-effect */
474 status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
477 if (status & ATMEL_US_PARE)
478 port->icount.parity++;
479 if (status & ATMEL_US_FRAME)
480 port->icount.frame++;
481 if (status & ATMEL_US_OVRE)
482 port->icount.overrun++;
486 * Characters received (called from interrupt handler)
488 static void atmel_rx_chars(struct uart_port *port)
490 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
491 unsigned int status, ch;
493 status = UART_GET_CSR(port);
494 while (status & ATMEL_US_RXRDY) {
495 ch = UART_GET_CHAR(port);
498 * note that the error handling code is
499 * out of the main execution path
501 if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
502 | ATMEL_US_OVRE | ATMEL_US_RXBRK)
503 || atmel_port->break_active)) {
506 UART_PUT_CR(port, ATMEL_US_RSTSTA);
508 if (status & ATMEL_US_RXBRK
509 && !atmel_port->break_active) {
510 atmel_port->break_active = 1;
511 UART_PUT_IER(port, ATMEL_US_RXBRK);
514 * This is either the end-of-break
515 * condition or we've received at
516 * least one character without RXBRK
517 * being set. In both cases, the next
518 * RXBRK will indicate start-of-break.
520 UART_PUT_IDR(port, ATMEL_US_RXBRK);
521 status &= ~ATMEL_US_RXBRK;
522 atmel_port->break_active = 0;
526 atmel_buffer_rx_char(port, status, ch);
527 status = UART_GET_CSR(port);
530 tasklet_schedule(&atmel_port->tasklet);
534 * Transmit characters (called from tasklet with TXRDY interrupt
537 static void atmel_tx_chars(struct uart_port *port)
539 struct circ_buf *xmit = &port->state->xmit;
540 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
542 if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) {
543 UART_PUT_CHAR(port, port->x_char);
547 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
550 while (UART_GET_CSR(port) & atmel_port->tx_done_mask) {
551 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
552 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
554 if (uart_circ_empty(xmit))
558 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
559 uart_write_wakeup(port);
561 if (!uart_circ_empty(xmit))
562 /* Enable interrupts */
563 UART_PUT_IER(port, atmel_port->tx_done_mask);
567 * receive interrupt handler.
570 atmel_handle_receive(struct uart_port *port, unsigned int pending)
572 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
574 if (atmel_use_dma_rx(port)) {
576 * PDC receive. Just schedule the tasklet and let it
577 * figure out the details.
579 * TODO: We're not handling error flags correctly at
582 if (pending & (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)) {
583 UART_PUT_IDR(port, (ATMEL_US_ENDRX
584 | ATMEL_US_TIMEOUT));
585 tasklet_schedule(&atmel_port->tasklet);
588 if (pending & (ATMEL_US_RXBRK | ATMEL_US_OVRE |
589 ATMEL_US_FRAME | ATMEL_US_PARE))
590 atmel_pdc_rxerr(port, pending);
593 /* Interrupt receive */
594 if (pending & ATMEL_US_RXRDY)
595 atmel_rx_chars(port);
596 else if (pending & ATMEL_US_RXBRK) {
598 * End of break detected. If it came along with a
599 * character, atmel_rx_chars will handle it.
601 UART_PUT_CR(port, ATMEL_US_RSTSTA);
602 UART_PUT_IDR(port, ATMEL_US_RXBRK);
603 atmel_port->break_active = 0;
608 * transmit interrupt handler. (Transmit is IRQF_NODELAY safe)
611 atmel_handle_transmit(struct uart_port *port, unsigned int pending)
613 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
615 if (pending & atmel_port->tx_done_mask) {
616 /* Either PDC or interrupt transmission */
617 UART_PUT_IDR(port, atmel_port->tx_done_mask);
618 tasklet_schedule(&atmel_port->tasklet);
623 * status flags interrupt handler.
626 atmel_handle_status(struct uart_port *port, unsigned int pending,
629 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
631 if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC
633 atmel_port->irq_status = status;
634 tasklet_schedule(&atmel_port->tasklet);
641 static irqreturn_t atmel_interrupt(int irq, void *dev_id)
643 struct uart_port *port = dev_id;
644 unsigned int status, pending, pass_counter = 0;
647 status = UART_GET_CSR(port);
648 pending = status & UART_GET_IMR(port);
652 atmel_handle_receive(port, pending);
653 atmel_handle_status(port, pending, status);
654 atmel_handle_transmit(port, pending);
655 } while (pass_counter++ < ATMEL_ISR_PASS_LIMIT);
657 return pass_counter ? IRQ_HANDLED : IRQ_NONE;
661 * Called from tasklet with ENDTX and TXBUFE interrupts disabled.
663 static void atmel_tx_dma(struct uart_port *port)
665 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
666 struct circ_buf *xmit = &port->state->xmit;
667 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
670 /* nothing left to transmit? */
671 if (UART_GET_TCR(port))
674 xmit->tail += pdc->ofs;
675 xmit->tail &= UART_XMIT_SIZE - 1;
677 port->icount.tx += pdc->ofs;
680 /* more to transmit - setup next transfer */
682 /* disable PDC transmit */
683 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
685 if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
686 dma_sync_single_for_device(port->dev,
691 count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
694 UART_PUT_TPR(port, pdc->dma_addr + xmit->tail);
695 UART_PUT_TCR(port, count);
696 /* re-enable PDC transmit */
697 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
698 /* Enable interrupts */
699 UART_PUT_IER(port, atmel_port->tx_done_mask);
701 if ((atmel_port->rs485.flags & SER_RS485_ENABLED) &&
702 !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX)) {
703 /* DMA done, stop TX, start RX for RS485 */
704 atmel_start_rx(port);
708 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
709 uart_write_wakeup(port);
712 static void atmel_rx_from_ring(struct uart_port *port)
714 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
715 struct circ_buf *ring = &atmel_port->rx_ring;
719 while (ring->head != ring->tail) {
720 struct atmel_uart_char c;
722 /* Make sure c is loaded after head. */
725 c = ((struct atmel_uart_char *)ring->buf)[ring->tail];
727 ring->tail = (ring->tail + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
734 * note that the error handling code is
735 * out of the main execution path
737 if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
738 | ATMEL_US_OVRE | ATMEL_US_RXBRK))) {
739 if (status & ATMEL_US_RXBRK) {
740 /* ignore side-effect */
741 status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
744 if (uart_handle_break(port))
747 if (status & ATMEL_US_PARE)
748 port->icount.parity++;
749 if (status & ATMEL_US_FRAME)
750 port->icount.frame++;
751 if (status & ATMEL_US_OVRE)
752 port->icount.overrun++;
754 status &= port->read_status_mask;
756 if (status & ATMEL_US_RXBRK)
758 else if (status & ATMEL_US_PARE)
760 else if (status & ATMEL_US_FRAME)
765 if (uart_handle_sysrq_char(port, c.ch))
768 uart_insert_char(port, status, ATMEL_US_OVRE, c.ch, flg);
772 * Drop the lock here since it might end up calling
773 * uart_start(), which takes the lock.
775 spin_unlock(&port->lock);
776 tty_flip_buffer_push(&port->state->port);
777 spin_lock(&port->lock);
780 static void atmel_rx_from_dma(struct uart_port *port)
782 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
783 struct tty_port *tport = &port->state->port;
784 struct atmel_dma_buffer *pdc;
785 int rx_idx = atmel_port->pdc_rx_idx;
791 /* Reset the UART timeout early so that we don't miss one */
792 UART_PUT_CR(port, ATMEL_US_STTTO);
794 pdc = &atmel_port->pdc_rx[rx_idx];
795 head = UART_GET_RPR(port) - pdc->dma_addr;
798 /* If the PDC has switched buffers, RPR won't contain
799 * any address within the current buffer. Since head
800 * is unsigned, we just need a one-way comparison to
803 * In this case, we just need to consume the entire
804 * buffer and resubmit it for DMA. This will clear the
805 * ENDRX bit as well, so that we can safely re-enable
806 * all interrupts below.
808 head = min(head, pdc->dma_size);
810 if (likely(head != tail)) {
811 dma_sync_single_for_cpu(port->dev, pdc->dma_addr,
812 pdc->dma_size, DMA_FROM_DEVICE);
815 * head will only wrap around when we recycle
816 * the DMA buffer, and when that happens, we
817 * explicitly set tail to 0. So head will
818 * always be greater than tail.
822 tty_insert_flip_string(tport, pdc->buf + pdc->ofs,
825 dma_sync_single_for_device(port->dev, pdc->dma_addr,
826 pdc->dma_size, DMA_FROM_DEVICE);
828 port->icount.rx += count;
833 * If the current buffer is full, we need to check if
834 * the next one contains any additional data.
836 if (head >= pdc->dma_size) {
838 UART_PUT_RNPR(port, pdc->dma_addr);
839 UART_PUT_RNCR(port, pdc->dma_size);
842 atmel_port->pdc_rx_idx = rx_idx;
844 } while (head >= pdc->dma_size);
847 * Drop the lock here since it might end up calling
848 * uart_start(), which takes the lock.
850 spin_unlock(&port->lock);
851 tty_flip_buffer_push(tport);
852 spin_lock(&port->lock);
854 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
858 * tasklet handling tty stuff outside the interrupt handler.
860 static void atmel_tasklet_func(unsigned long data)
862 struct uart_port *port = (struct uart_port *)data;
863 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
865 unsigned int status_change;
867 /* The interrupt handler does not take the lock */
868 spin_lock(&port->lock);
870 if (atmel_use_dma_tx(port))
873 atmel_tx_chars(port);
875 status = atmel_port->irq_status;
876 status_change = status ^ atmel_port->irq_status_prev;
878 if (status_change & (ATMEL_US_RI | ATMEL_US_DSR
879 | ATMEL_US_DCD | ATMEL_US_CTS)) {
880 /* TODO: All reads to CSR will clear these interrupts! */
881 if (status_change & ATMEL_US_RI)
883 if (status_change & ATMEL_US_DSR)
885 if (status_change & ATMEL_US_DCD)
886 uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
887 if (status_change & ATMEL_US_CTS)
888 uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
890 wake_up_interruptible(&port->state->port.delta_msr_wait);
892 atmel_port->irq_status_prev = status;
895 if (atmel_use_dma_rx(port))
896 atmel_rx_from_dma(port);
898 atmel_rx_from_ring(port);
900 spin_unlock(&port->lock);
904 * Perform initialization and enable port for reception
906 static int atmel_startup(struct uart_port *port)
908 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
909 struct tty_struct *tty = port->state->port.tty;
913 * Ensure that no interrupts are enabled otherwise when
914 * request_irq() is called we could get stuck trying to
915 * handle an unexpected interrupt
917 UART_PUT_IDR(port, -1);
922 retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED,
923 tty ? tty->name : "atmel_serial", port);
925 printk("atmel_serial: atmel_startup - Can't get irq\n");
930 * Initialize DMA (if necessary)
932 if (atmel_use_dma_rx(port)) {
935 for (i = 0; i < 2; i++) {
936 struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
938 pdc->buf = kmalloc(PDC_BUFFER_SIZE, GFP_KERNEL);
939 if (pdc->buf == NULL) {
941 dma_unmap_single(port->dev,
942 atmel_port->pdc_rx[0].dma_addr,
945 kfree(atmel_port->pdc_rx[0].buf);
947 free_irq(port->irq, port);
950 pdc->dma_addr = dma_map_single(port->dev,
954 pdc->dma_size = PDC_BUFFER_SIZE;
958 atmel_port->pdc_rx_idx = 0;
960 UART_PUT_RPR(port, atmel_port->pdc_rx[0].dma_addr);
961 UART_PUT_RCR(port, PDC_BUFFER_SIZE);
963 UART_PUT_RNPR(port, atmel_port->pdc_rx[1].dma_addr);
964 UART_PUT_RNCR(port, PDC_BUFFER_SIZE);
966 if (atmel_use_dma_tx(port)) {
967 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
968 struct circ_buf *xmit = &port->state->xmit;
970 pdc->buf = xmit->buf;
971 pdc->dma_addr = dma_map_single(port->dev,
975 pdc->dma_size = UART_XMIT_SIZE;
980 * If there is a specific "open" function (to register
981 * control line interrupts)
983 if (atmel_open_hook) {
984 retval = atmel_open_hook(port);
986 free_irq(port->irq, port);
991 /* Save current CSR for comparison in atmel_tasklet_func() */
992 atmel_port->irq_status_prev = UART_GET_CSR(port);
993 atmel_port->irq_status = atmel_port->irq_status_prev;
996 * Finally, enable the serial port
998 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
999 /* enable xmit & rcvr */
1000 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1002 if (atmel_use_dma_rx(port)) {
1003 /* set UART timeout */
1004 UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
1005 UART_PUT_CR(port, ATMEL_US_STTTO);
1007 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
1008 /* enable PDC controller */
1009 UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
1011 /* enable receive only */
1012 UART_PUT_IER(port, ATMEL_US_RXRDY);
1021 static void atmel_shutdown(struct uart_port *port)
1023 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1025 * Ensure everything is stopped.
1027 atmel_stop_rx(port);
1028 atmel_stop_tx(port);
1031 * Shut-down the DMA.
1033 if (atmel_use_dma_rx(port)) {
1036 for (i = 0; i < 2; i++) {
1037 struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
1039 dma_unmap_single(port->dev,
1046 if (atmel_use_dma_tx(port)) {
1047 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
1049 dma_unmap_single(port->dev,
1056 * Disable all interrupts, port and break condition.
1058 UART_PUT_CR(port, ATMEL_US_RSTSTA);
1059 UART_PUT_IDR(port, -1);
1062 * Free the interrupt
1064 free_irq(port->irq, port);
1067 * If there is a specific "close" function (to unregister
1068 * control line interrupts)
1070 if (atmel_close_hook)
1071 atmel_close_hook(port);
1075 * Flush any TX data submitted for DMA. Called when the TX circular
1078 static void atmel_flush_buffer(struct uart_port *port)
1080 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1082 if (atmel_use_dma_tx(port)) {
1083 UART_PUT_TCR(port, 0);
1084 atmel_port->pdc_tx.ofs = 0;
1089 * Power / Clock management.
1091 static void atmel_serial_pm(struct uart_port *port, unsigned int state,
1092 unsigned int oldstate)
1094 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1099 * Enable the peripheral clock for this serial port.
1100 * This is called on uart_open() or a resume event.
1102 clk_prepare_enable(atmel_port->clk);
1104 /* re-enable interrupts if we disabled some on suspend */
1105 UART_PUT_IER(port, atmel_port->backup_imr);
1108 /* Back up the interrupt mask and disable all interrupts */
1109 atmel_port->backup_imr = UART_GET_IMR(port);
1110 UART_PUT_IDR(port, -1);
1113 * Disable the peripheral clock for this serial port.
1114 * This is called on uart_close() or a suspend event.
1116 clk_disable_unprepare(atmel_port->clk);
1119 printk(KERN_ERR "atmel_serial: unknown pm %d\n", state);
1124 * Change the port parameters
1126 static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
1127 struct ktermios *old)
1129 unsigned long flags;
1130 unsigned int mode, imr, quot, baud;
1131 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1133 /* Get current mode register */
1134 mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL
1135 | ATMEL_US_NBSTOP | ATMEL_US_PAR
1138 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
1139 quot = uart_get_divisor(port, baud);
1141 if (quot > 65535) { /* BRGR is 16-bit, so switch to slower clock */
1143 mode |= ATMEL_US_USCLKS_MCK_DIV8;
1147 switch (termios->c_cflag & CSIZE) {
1149 mode |= ATMEL_US_CHRL_5;
1152 mode |= ATMEL_US_CHRL_6;
1155 mode |= ATMEL_US_CHRL_7;
1158 mode |= ATMEL_US_CHRL_8;
1163 if (termios->c_cflag & CSTOPB)
1164 mode |= ATMEL_US_NBSTOP_2;
1167 if (termios->c_cflag & PARENB) {
1168 /* Mark or Space parity */
1169 if (termios->c_cflag & CMSPAR) {
1170 if (termios->c_cflag & PARODD)
1171 mode |= ATMEL_US_PAR_MARK;
1173 mode |= ATMEL_US_PAR_SPACE;
1174 } else if (termios->c_cflag & PARODD)
1175 mode |= ATMEL_US_PAR_ODD;
1177 mode |= ATMEL_US_PAR_EVEN;
1179 mode |= ATMEL_US_PAR_NONE;
1181 /* hardware handshake (RTS/CTS) */
1182 if (termios->c_cflag & CRTSCTS)
1183 mode |= ATMEL_US_USMODE_HWHS;
1185 mode |= ATMEL_US_USMODE_NORMAL;
1187 spin_lock_irqsave(&port->lock, flags);
1189 port->read_status_mask = ATMEL_US_OVRE;
1190 if (termios->c_iflag & INPCK)
1191 port->read_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
1192 if (termios->c_iflag & (BRKINT | PARMRK))
1193 port->read_status_mask |= ATMEL_US_RXBRK;
1195 if (atmel_use_dma_rx(port))
1196 /* need to enable error interrupts */
1197 UART_PUT_IER(port, port->read_status_mask);
1200 * Characters to ignore
1202 port->ignore_status_mask = 0;
1203 if (termios->c_iflag & IGNPAR)
1204 port->ignore_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
1205 if (termios->c_iflag & IGNBRK) {
1206 port->ignore_status_mask |= ATMEL_US_RXBRK;
1208 * If we're ignoring parity and break indicators,
1209 * ignore overruns too (for real raw support).
1211 if (termios->c_iflag & IGNPAR)
1212 port->ignore_status_mask |= ATMEL_US_OVRE;
1214 /* TODO: Ignore all characters if CREAD is set.*/
1216 /* update the per-port timeout */
1217 uart_update_timeout(port, termios->c_cflag, baud);
1220 * save/disable interrupts. The tty layer will ensure that the
1221 * transmitter is empty if requested by the caller, so there's
1222 * no need to wait for it here.
1224 imr = UART_GET_IMR(port);
1225 UART_PUT_IDR(port, -1);
1227 /* disable receiver and transmitter */
1228 UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
1230 /* Resetting serial mode to RS232 (0x0) */
1231 mode &= ~ATMEL_US_USMODE;
1233 if (atmel_port->rs485.flags & SER_RS485_ENABLED) {
1234 dev_dbg(port->dev, "Setting UART to RS485\n");
1235 if ((atmel_port->rs485.delay_rts_after_send) > 0)
1237 atmel_port->rs485.delay_rts_after_send);
1238 mode |= ATMEL_US_USMODE_RS485;
1240 dev_dbg(port->dev, "Setting UART to RS232\n");
1243 /* set the parity, stop bits and data size */
1244 UART_PUT_MR(port, mode);
1246 /* set the baud rate */
1247 UART_PUT_BRGR(port, quot);
1248 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1249 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1251 /* restore interrupts */
1252 UART_PUT_IER(port, imr);
1254 /* CTS flow-control and modem-status interrupts */
1255 if (UART_ENABLE_MS(port, termios->c_cflag))
1256 port->ops->enable_ms(port);
1258 spin_unlock_irqrestore(&port->lock, flags);
1261 static void atmel_set_ldisc(struct uart_port *port, int new)
1264 port->flags |= UPF_HARDPPS_CD;
1265 atmel_enable_ms(port);
1267 port->flags &= ~UPF_HARDPPS_CD;
1272 * Return string describing the specified port
1274 static const char *atmel_type(struct uart_port *port)
1276 return (port->type == PORT_ATMEL) ? "ATMEL_SERIAL" : NULL;
1280 * Release the memory region(s) being used by 'port'.
1282 static void atmel_release_port(struct uart_port *port)
1284 struct platform_device *pdev = to_platform_device(port->dev);
1285 int size = pdev->resource[0].end - pdev->resource[0].start + 1;
1287 release_mem_region(port->mapbase, size);
1289 if (port->flags & UPF_IOREMAP) {
1290 iounmap(port->membase);
1291 port->membase = NULL;
1296 * Request the memory region(s) being used by 'port'.
1298 static int atmel_request_port(struct uart_port *port)
1300 struct platform_device *pdev = to_platform_device(port->dev);
1301 int size = pdev->resource[0].end - pdev->resource[0].start + 1;
1303 if (!request_mem_region(port->mapbase, size, "atmel_serial"))
1306 if (port->flags & UPF_IOREMAP) {
1307 port->membase = ioremap(port->mapbase, size);
1308 if (port->membase == NULL) {
1309 release_mem_region(port->mapbase, size);
1318 * Configure/autoconfigure the port.
1320 static void atmel_config_port(struct uart_port *port, int flags)
1322 if (flags & UART_CONFIG_TYPE) {
1323 port->type = PORT_ATMEL;
1324 atmel_request_port(port);
1329 * Verify the new serial_struct (for TIOCSSERIAL).
1331 static int atmel_verify_port(struct uart_port *port, struct serial_struct *ser)
1334 if (ser->type != PORT_UNKNOWN && ser->type != PORT_ATMEL)
1336 if (port->irq != ser->irq)
1338 if (ser->io_type != SERIAL_IO_MEM)
1340 if (port->uartclk / 16 != ser->baud_base)
1342 if ((void *)port->mapbase != ser->iomem_base)
1344 if (port->iobase != ser->port)
1351 #ifdef CONFIG_CONSOLE_POLL
1352 static int atmel_poll_get_char(struct uart_port *port)
1354 while (!(UART_GET_CSR(port) & ATMEL_US_RXRDY))
1357 return UART_GET_CHAR(port);
1360 static void atmel_poll_put_char(struct uart_port *port, unsigned char ch)
1362 while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
1365 UART_PUT_CHAR(port, ch);
1370 atmel_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg)
1372 struct serial_rs485 rs485conf;
1376 if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg,
1380 atmel_config_rs485(port, &rs485conf);
1384 if (copy_to_user((struct serial_rs485 *) arg,
1385 &(to_atmel_uart_port(port)->rs485),
1391 return -ENOIOCTLCMD;
1398 static struct uart_ops atmel_pops = {
1399 .tx_empty = atmel_tx_empty,
1400 .set_mctrl = atmel_set_mctrl,
1401 .get_mctrl = atmel_get_mctrl,
1402 .stop_tx = atmel_stop_tx,
1403 .start_tx = atmel_start_tx,
1404 .stop_rx = atmel_stop_rx,
1405 .enable_ms = atmel_enable_ms,
1406 .break_ctl = atmel_break_ctl,
1407 .startup = atmel_startup,
1408 .shutdown = atmel_shutdown,
1409 .flush_buffer = atmel_flush_buffer,
1410 .set_termios = atmel_set_termios,
1411 .set_ldisc = atmel_set_ldisc,
1413 .release_port = atmel_release_port,
1414 .request_port = atmel_request_port,
1415 .config_port = atmel_config_port,
1416 .verify_port = atmel_verify_port,
1417 .pm = atmel_serial_pm,
1418 .ioctl = atmel_ioctl,
1419 #ifdef CONFIG_CONSOLE_POLL
1420 .poll_get_char = atmel_poll_get_char,
1421 .poll_put_char = atmel_poll_put_char,
1425 static void atmel_of_init_port(struct atmel_uart_port *atmel_port,
1426 struct device_node *np)
1430 /* DMA/PDC usage specification */
1431 if (of_get_property(np, "atmel,use-dma-rx", NULL))
1432 atmel_port->use_dma_rx = 1;
1434 atmel_port->use_dma_rx = 0;
1435 if (of_get_property(np, "atmel,use-dma-tx", NULL))
1436 atmel_port->use_dma_tx = 1;
1438 atmel_port->use_dma_tx = 0;
1440 /* rs485 properties */
1441 if (of_property_read_u32_array(np, "rs485-rts-delay",
1442 rs485_delay, 2) == 0) {
1443 struct serial_rs485 *rs485conf = &atmel_port->rs485;
1445 rs485conf->delay_rts_before_send = rs485_delay[0];
1446 rs485conf->delay_rts_after_send = rs485_delay[1];
1447 rs485conf->flags = 0;
1449 if (of_get_property(np, "rs485-rx-during-tx", NULL))
1450 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1452 if (of_get_property(np, "linux,rs485-enabled-at-boot-time", NULL))
1453 rs485conf->flags |= SER_RS485_ENABLED;
1458 * Configure the port from the platform device resource info.
1460 static int atmel_init_port(struct atmel_uart_port *atmel_port,
1461 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 if (IS_ERR(atmel_port->clk)) {
1500 ret = PTR_ERR(atmel_port->clk);
1501 atmel_port->clk = NULL;
1504 ret = clk_prepare_enable(atmel_port->clk);
1506 clk_put(atmel_port->clk);
1507 atmel_port->clk = NULL;
1510 port->uartclk = clk_get_rate(atmel_port->clk);
1511 clk_disable_unprepare(atmel_port->clk);
1512 /* only enable clock when USART is in use */
1515 /* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
1516 if (atmel_port->rs485.flags & SER_RS485_ENABLED)
1517 atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
1518 else if (atmel_use_dma_tx(port)) {
1519 port->fifosize = PDC_BUFFER_SIZE;
1520 atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE;
1522 atmel_port->tx_done_mask = ATMEL_US_TXRDY;
1528 struct platform_device *atmel_default_console_device; /* the serial console device */
1530 #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
1531 static void atmel_console_putchar(struct uart_port *port, int ch)
1533 while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
1535 UART_PUT_CHAR(port, ch);
1539 * Interrupts are disabled on entering
1541 static void atmel_console_write(struct console *co, const char *s, u_int count)
1543 struct uart_port *port = &atmel_ports[co->index].uart;
1544 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1545 unsigned int status, imr;
1546 unsigned int pdc_tx;
1549 * First, save IMR and then disable interrupts
1551 imr = UART_GET_IMR(port);
1552 UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask);
1554 /* Store PDC transmit status and disable it */
1555 pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN;
1556 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
1558 uart_console_write(port, s, count, atmel_console_putchar);
1561 * Finally, wait for transmitter to become empty
1565 status = UART_GET_CSR(port);
1566 } while (!(status & ATMEL_US_TXRDY));
1568 /* Restore PDC transmit status */
1570 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
1572 /* set interrupts back the way they were */
1573 UART_PUT_IER(port, imr);
1577 * If the port was already initialised (eg, by a boot loader),
1578 * try to determine the current setup.
1580 static void __init atmel_console_get_options(struct uart_port *port, int *baud,
1581 int *parity, int *bits)
1583 unsigned int mr, quot;
1586 * If the baud rate generator isn't running, the port wasn't
1587 * initialized by the boot loader.
1589 quot = UART_GET_BRGR(port) & ATMEL_US_CD;
1593 mr = UART_GET_MR(port) & ATMEL_US_CHRL;
1594 if (mr == ATMEL_US_CHRL_8)
1599 mr = UART_GET_MR(port) & ATMEL_US_PAR;
1600 if (mr == ATMEL_US_PAR_EVEN)
1602 else if (mr == ATMEL_US_PAR_ODD)
1606 * The serial core only rounds down when matching this to a
1607 * supported baud rate. Make sure we don't end up slightly
1608 * lower than one of those, as it would make us fall through
1609 * to a much lower baud rate than we really want.
1611 *baud = port->uartclk / (16 * (quot - 1));
1614 static int __init atmel_console_setup(struct console *co, char *options)
1617 struct uart_port *port = &atmel_ports[co->index].uart;
1623 if (port->membase == NULL) {
1624 /* Port not initialized yet - delay setup */
1628 ret = clk_prepare_enable(atmel_ports[co->index].clk);
1632 UART_PUT_IDR(port, -1);
1633 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1634 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1637 uart_parse_options(options, &baud, &parity, &bits, &flow);
1639 atmel_console_get_options(port, &baud, &parity, &bits);
1641 return uart_set_options(port, co, baud, parity, bits, flow);
1644 static struct uart_driver atmel_uart;
1646 static struct console atmel_console = {
1647 .name = ATMEL_DEVICENAME,
1648 .write = atmel_console_write,
1649 .device = uart_console_device,
1650 .setup = atmel_console_setup,
1651 .flags = CON_PRINTBUFFER,
1653 .data = &atmel_uart,
1656 #define ATMEL_CONSOLE_DEVICE (&atmel_console)
1659 * Early console initialization (before VM subsystem initialized).
1661 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 ret = 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 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;
1778 BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
1781 ret = of_alias_get_id(np, "serial");
1787 /* port id not found in platform data nor device-tree aliases:
1788 * auto-enumerate it */
1789 ret = find_first_zero_bit(atmel_ports_in_use, ATMEL_MAX_UART);
1791 if (ret >= ATMEL_MAX_UART) {
1796 if (test_and_set_bit(ret, atmel_ports_in_use)) {
1797 /* port already in use */
1802 port = &atmel_ports[ret];
1803 port->backup_imr = 0;
1804 port->uart.line = ret;
1806 ret = atmel_init_port(port, pdev);
1810 if (!atmel_use_dma_rx(&port->uart)) {
1812 data = kmalloc(sizeof(struct atmel_uart_char)
1813 * ATMEL_SERIAL_RINGSIZE, GFP_KERNEL);
1815 goto err_alloc_ring;
1816 port->rx_ring.buf = data;
1819 ret = uart_add_one_port(&atmel_uart, &port->uart);
1823 #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
1824 if (atmel_is_console_port(&port->uart)
1825 && ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) {
1827 * The serial core enabled the clock for us, so undo
1828 * the clk_prepare_enable() in atmel_console_setup()
1830 clk_disable_unprepare(port->clk);
1834 device_init_wakeup(&pdev->dev, 1);
1835 platform_set_drvdata(pdev, port);
1837 if (port->rs485.flags & SER_RS485_ENABLED) {
1838 UART_PUT_MR(&port->uart, ATMEL_US_USMODE_NORMAL);
1839 UART_PUT_CR(&port->uart, ATMEL_US_RTSEN);
1845 kfree(port->rx_ring.buf);
1846 port->rx_ring.buf = NULL;
1848 if (!atmel_is_console_port(&port->uart)) {
1856 static int atmel_serial_remove(struct platform_device *pdev)
1858 struct uart_port *port = platform_get_drvdata(pdev);
1859 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1862 device_init_wakeup(&pdev->dev, 0);
1863 platform_set_drvdata(pdev, NULL);
1865 ret = uart_remove_one_port(&atmel_uart, port);
1867 tasklet_kill(&atmel_port->tasklet);
1868 kfree(atmel_port->rx_ring.buf);
1870 /* "port" is allocated statically, so we shouldn't free it */
1872 clear_bit(port->line, atmel_ports_in_use);
1874 clk_put(atmel_port->clk);
1879 static struct platform_driver atmel_serial_driver = {
1880 .probe = atmel_serial_probe,
1881 .remove = atmel_serial_remove,
1882 .suspend = atmel_serial_suspend,
1883 .resume = atmel_serial_resume,
1885 .name = "atmel_usart",
1886 .owner = THIS_MODULE,
1887 .of_match_table = of_match_ptr(atmel_serial_dt_ids),
1891 static int __init atmel_serial_init(void)
1895 ret = uart_register_driver(&atmel_uart);
1899 ret = platform_driver_register(&atmel_serial_driver);
1901 uart_unregister_driver(&atmel_uart);
1906 static void __exit atmel_serial_exit(void)
1908 platform_driver_unregister(&atmel_serial_driver);
1909 uart_unregister_driver(&atmel_uart);
1912 module_init(atmel_serial_init);
1913 module_exit(atmel_serial_exit);
1915 MODULE_AUTHOR("Rick Bronson");
1916 MODULE_DESCRIPTION("Atmel AT91 / AT32 serial port driver");
1917 MODULE_LICENSE("GPL");
1918 MODULE_ALIAS("platform:atmel_usart");