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/of_gpio.h>
39 #include <linux/dma-mapping.h>
40 #include <linux/dmaengine.h>
41 #include <linux/atmel_pdc.h>
42 #include <linux/atmel_serial.h>
43 #include <linux/uaccess.h>
44 #include <linux/platform_data/atmel.h>
45 #include <linux/timer.h>
46 #include <linux/gpio.h>
47 #include <linux/gpio/consumer.h>
48 #include <linux/err.h>
49 #include <linux/irq.h>
52 #include <asm/ioctls.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 #include "serial_mctrl_gpio.h"
66 static void atmel_start_rx(struct uart_port *port);
67 static void atmel_stop_rx(struct uart_port *port);
69 #ifdef CONFIG_SERIAL_ATMEL_TTYAT
71 /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we
72 * should coexist with the 8250 driver, such as if we have an external 16C550
74 #define SERIAL_ATMEL_MAJOR 204
75 #define MINOR_START 154
76 #define ATMEL_DEVICENAME "ttyAT"
80 /* Use device name ttyS, major 4, minor 64-68. This is the usual serial port
81 * name, but it is legally reserved for the 8250 driver. */
82 #define SERIAL_ATMEL_MAJOR TTY_MAJOR
83 #define MINOR_START 64
84 #define ATMEL_DEVICENAME "ttyS"
88 #define ATMEL_ISR_PASS_LIMIT 256
90 /* UART registers. CR is write-only, hence no GET macro */
91 #define UART_PUT_CR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_CR)
92 #define UART_GET_MR(port) __raw_readl((port)->membase + ATMEL_US_MR)
93 #define UART_PUT_MR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_MR)
94 #define UART_PUT_IER(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IER)
95 #define UART_PUT_IDR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_IDR)
96 #define UART_GET_IMR(port) __raw_readl((port)->membase + ATMEL_US_IMR)
97 #define UART_GET_CSR(port) __raw_readl((port)->membase + ATMEL_US_CSR)
98 #define UART_GET_CHAR(port) __raw_readl((port)->membase + ATMEL_US_RHR)
99 #define UART_PUT_CHAR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_THR)
100 #define UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR)
101 #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_BRGR)
102 #define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_RTOR)
103 #define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase + ATMEL_US_TTGR)
104 #define UART_GET_IP_NAME(port) __raw_readl((port)->membase + ATMEL_US_NAME)
105 #define UART_GET_IP_VERSION(port) __raw_readl((port)->membase + ATMEL_US_VERSION)
108 #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR)
109 #define UART_GET_PTSR(port) __raw_readl((port)->membase + ATMEL_PDC_PTSR)
111 #define UART_PUT_RPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RPR)
112 #define UART_GET_RPR(port) __raw_readl((port)->membase + ATMEL_PDC_RPR)
113 #define UART_PUT_RCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RCR)
114 #define UART_PUT_RNPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNPR)
115 #define UART_PUT_RNCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RNCR)
117 #define UART_PUT_TPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TPR)
118 #define UART_PUT_TCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_TCR)
119 #define UART_GET_TCR(port) __raw_readl((port)->membase + ATMEL_PDC_TCR)
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 bool use_dma_rx; /* enable DMA receiver */
146 bool use_pdc_rx; /* enable PDC receiver */
147 short pdc_rx_idx; /* current PDC RX buffer */
148 struct atmel_dma_buffer pdc_rx[2]; /* PDC receier */
150 bool use_dma_tx; /* enable DMA transmitter */
151 bool use_pdc_tx; /* enable PDC transmitter */
152 struct atmel_dma_buffer pdc_tx; /* PDC transmitter */
154 spinlock_t lock_tx; /* port lock */
155 spinlock_t lock_rx; /* port lock */
156 struct dma_chan *chan_tx;
157 struct dma_chan *chan_rx;
158 struct dma_async_tx_descriptor *desc_tx;
159 struct dma_async_tx_descriptor *desc_rx;
160 dma_cookie_t cookie_tx;
161 dma_cookie_t cookie_rx;
162 struct scatterlist sg_tx;
163 struct scatterlist sg_rx;
164 struct tasklet_struct tasklet;
165 unsigned int irq_status;
166 unsigned int irq_status_prev;
168 struct circ_buf rx_ring;
170 struct mctrl_gpios *gpios;
171 int gpio_irq[UART_GPIO_MAX];
172 unsigned int tx_done_mask;
174 bool is_usart; /* usart or uart */
175 struct timer_list uart_timer; /* uart timer */
176 int (*prepare_rx)(struct uart_port *port);
177 int (*prepare_tx)(struct uart_port *port);
178 void (*schedule_rx)(struct uart_port *port);
179 void (*schedule_tx)(struct uart_port *port);
180 void (*release_rx)(struct uart_port *port);
181 void (*release_tx)(struct uart_port *port);
184 static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
185 static DECLARE_BITMAP(atmel_ports_in_use, ATMEL_MAX_UART);
188 static struct console atmel_console;
191 #if defined(CONFIG_OF)
192 static const struct of_device_id atmel_serial_dt_ids[] = {
193 { .compatible = "atmel,at91rm9200-usart" },
194 { .compatible = "atmel,at91sam9260-usart" },
198 MODULE_DEVICE_TABLE(of, atmel_serial_dt_ids);
201 static inline struct atmel_uart_port *
202 to_atmel_uart_port(struct uart_port *uart)
204 return container_of(uart, struct atmel_uart_port, uart);
207 #ifdef CONFIG_SERIAL_ATMEL_PDC
208 static bool atmel_use_pdc_rx(struct uart_port *port)
210 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
212 return atmel_port->use_pdc_rx;
215 static bool atmel_use_pdc_tx(struct uart_port *port)
217 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
219 return atmel_port->use_pdc_tx;
222 static bool atmel_use_pdc_rx(struct uart_port *port)
227 static bool atmel_use_pdc_tx(struct uart_port *port)
233 static bool atmel_use_dma_tx(struct uart_port *port)
235 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
237 return atmel_port->use_dma_tx;
240 static bool atmel_use_dma_rx(struct uart_port *port)
242 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
244 return atmel_port->use_dma_rx;
247 static unsigned int atmel_get_lines_status(struct uart_port *port)
249 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
250 unsigned int status, ret = 0;
252 status = UART_GET_CSR(port);
254 mctrl_gpio_get(atmel_port->gpios, &ret);
256 if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios,
259 status &= ~ATMEL_US_CTS;
261 status |= ATMEL_US_CTS;
264 if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios,
267 status &= ~ATMEL_US_DSR;
269 status |= ATMEL_US_DSR;
272 if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios,
275 status &= ~ATMEL_US_RI;
277 status |= ATMEL_US_RI;
280 if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(atmel_port->gpios,
283 status &= ~ATMEL_US_DCD;
285 status |= ATMEL_US_DCD;
291 /* Enable or disable the rs485 support */
292 static int atmel_config_rs485(struct uart_port *port,
293 struct serial_rs485 *rs485conf)
295 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
298 /* Disable interrupts */
299 UART_PUT_IDR(port, atmel_port->tx_done_mask);
301 mode = UART_GET_MR(port);
303 /* Resetting serial mode to RS232 (0x0) */
304 mode &= ~ATMEL_US_USMODE;
306 port->rs485 = *rs485conf;
308 if (rs485conf->flags & SER_RS485_ENABLED) {
309 dev_dbg(port->dev, "Setting UART to RS485\n");
310 atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
311 if ((rs485conf->delay_rts_after_send) > 0)
312 UART_PUT_TTGR(port, rs485conf->delay_rts_after_send);
313 mode |= ATMEL_US_USMODE_RS485;
315 dev_dbg(port->dev, "Setting UART to RS232\n");
316 if (atmel_use_pdc_tx(port))
317 atmel_port->tx_done_mask = ATMEL_US_ENDTX |
320 atmel_port->tx_done_mask = ATMEL_US_TXRDY;
322 UART_PUT_MR(port, mode);
324 /* Enable interrupts */
325 UART_PUT_IER(port, atmel_port->tx_done_mask);
331 * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
333 static u_int atmel_tx_empty(struct uart_port *port)
335 return (UART_GET_CSR(port) & ATMEL_US_TXEMPTY) ? TIOCSER_TEMT : 0;
339 * Set state of the modem control output lines
341 static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
343 unsigned int control = 0;
344 unsigned int mode = UART_GET_MR(port);
345 unsigned int rts_paused, rts_ready;
346 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
348 /* override mode to RS485 if needed, otherwise keep the current mode */
349 if (port->rs485.flags & SER_RS485_ENABLED) {
350 if ((port->rs485.delay_rts_after_send) > 0)
351 UART_PUT_TTGR(port, port->rs485.delay_rts_after_send);
352 mode &= ~ATMEL_US_USMODE;
353 mode |= ATMEL_US_USMODE_RS485;
356 /* set the RTS line state according to the mode */
357 if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) {
358 /* force RTS line to high level */
359 rts_paused = ATMEL_US_RTSEN;
361 /* give the control of the RTS line back to the hardware */
362 rts_ready = ATMEL_US_RTSDIS;
364 /* force RTS line to high level */
365 rts_paused = ATMEL_US_RTSDIS;
367 /* force RTS line to low level */
368 rts_ready = ATMEL_US_RTSEN;
371 if (mctrl & TIOCM_RTS)
372 control |= rts_ready;
374 control |= rts_paused;
376 if (mctrl & TIOCM_DTR)
377 control |= ATMEL_US_DTREN;
379 control |= ATMEL_US_DTRDIS;
381 UART_PUT_CR(port, control);
383 mctrl_gpio_set(atmel_port->gpios, mctrl);
385 /* Local loopback mode? */
386 mode &= ~ATMEL_US_CHMODE;
387 if (mctrl & TIOCM_LOOP)
388 mode |= ATMEL_US_CHMODE_LOC_LOOP;
390 mode |= ATMEL_US_CHMODE_NORMAL;
392 UART_PUT_MR(port, mode);
396 * Get state of the modem control input lines
398 static u_int atmel_get_mctrl(struct uart_port *port)
400 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
401 unsigned int ret = 0, status;
403 status = UART_GET_CSR(port);
406 * The control signals are active low.
408 if (!(status & ATMEL_US_DCD))
410 if (!(status & ATMEL_US_CTS))
412 if (!(status & ATMEL_US_DSR))
414 if (!(status & ATMEL_US_RI))
417 return mctrl_gpio_get(atmel_port->gpios, &ret);
423 static void atmel_stop_tx(struct uart_port *port)
425 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
427 if (atmel_use_pdc_tx(port)) {
428 /* disable PDC transmit */
429 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
431 /* Disable interrupts */
432 UART_PUT_IDR(port, atmel_port->tx_done_mask);
434 if ((port->rs485.flags & SER_RS485_ENABLED) &&
435 !(port->rs485.flags & SER_RS485_RX_DURING_TX))
436 atmel_start_rx(port);
440 * Start transmitting.
442 static void atmel_start_tx(struct uart_port *port)
444 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
446 if (atmel_use_pdc_tx(port)) {
447 if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN)
448 /* The transmitter is already running. Yes, we
452 if ((port->rs485.flags & SER_RS485_ENABLED) &&
453 !(port->rs485.flags & SER_RS485_RX_DURING_TX))
456 /* re-enable PDC transmit */
457 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
459 /* Enable interrupts */
460 UART_PUT_IER(port, atmel_port->tx_done_mask);
464 * start receiving - port is in process of being opened.
466 static void atmel_start_rx(struct uart_port *port)
468 UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */
470 UART_PUT_CR(port, ATMEL_US_RXEN);
472 if (atmel_use_pdc_rx(port)) {
473 /* enable PDC controller */
474 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
475 port->read_status_mask);
476 UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
478 UART_PUT_IER(port, ATMEL_US_RXRDY);
483 * Stop receiving - port is in process of being closed.
485 static void atmel_stop_rx(struct uart_port *port)
487 UART_PUT_CR(port, ATMEL_US_RXDIS);
489 if (atmel_use_pdc_rx(port)) {
490 /* disable PDC receive */
491 UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS);
492 UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT |
493 port->read_status_mask);
495 UART_PUT_IDR(port, ATMEL_US_RXRDY);
500 * Enable modem status interrupts
502 static void atmel_enable_ms(struct uart_port *port)
504 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
508 * Interrupt should not be enabled twice
510 if (atmel_port->ms_irq_enabled)
513 atmel_port->ms_irq_enabled = true;
515 if (atmel_port->gpio_irq[UART_GPIO_CTS] >= 0)
516 enable_irq(atmel_port->gpio_irq[UART_GPIO_CTS]);
518 ier |= ATMEL_US_CTSIC;
520 if (atmel_port->gpio_irq[UART_GPIO_DSR] >= 0)
521 enable_irq(atmel_port->gpio_irq[UART_GPIO_DSR]);
523 ier |= ATMEL_US_DSRIC;
525 if (atmel_port->gpio_irq[UART_GPIO_RI] >= 0)
526 enable_irq(atmel_port->gpio_irq[UART_GPIO_RI]);
528 ier |= ATMEL_US_RIIC;
530 if (atmel_port->gpio_irq[UART_GPIO_DCD] >= 0)
531 enable_irq(atmel_port->gpio_irq[UART_GPIO_DCD]);
533 ier |= ATMEL_US_DCDIC;
535 UART_PUT_IER(port, ier);
539 * Disable modem status interrupts
541 static void atmel_disable_ms(struct uart_port *port)
543 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
547 * Interrupt should not be disabled twice
549 if (!atmel_port->ms_irq_enabled)
552 atmel_port->ms_irq_enabled = false;
554 if (atmel_port->gpio_irq[UART_GPIO_CTS] >= 0)
555 disable_irq(atmel_port->gpio_irq[UART_GPIO_CTS]);
557 idr |= ATMEL_US_CTSIC;
559 if (atmel_port->gpio_irq[UART_GPIO_DSR] >= 0)
560 disable_irq(atmel_port->gpio_irq[UART_GPIO_DSR]);
562 idr |= ATMEL_US_DSRIC;
564 if (atmel_port->gpio_irq[UART_GPIO_RI] >= 0)
565 disable_irq(atmel_port->gpio_irq[UART_GPIO_RI]);
567 idr |= ATMEL_US_RIIC;
569 if (atmel_port->gpio_irq[UART_GPIO_DCD] >= 0)
570 disable_irq(atmel_port->gpio_irq[UART_GPIO_DCD]);
572 idr |= ATMEL_US_DCDIC;
574 UART_PUT_IDR(port, idr);
578 * Control the transmission of a break signal
580 static void atmel_break_ctl(struct uart_port *port, int break_state)
582 if (break_state != 0)
583 UART_PUT_CR(port, ATMEL_US_STTBRK); /* start break */
585 UART_PUT_CR(port, ATMEL_US_STPBRK); /* stop break */
589 * Stores the incoming character in the ring buffer
592 atmel_buffer_rx_char(struct uart_port *port, unsigned int status,
595 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
596 struct circ_buf *ring = &atmel_port->rx_ring;
597 struct atmel_uart_char *c;
599 if (!CIRC_SPACE(ring->head, ring->tail, ATMEL_SERIAL_RINGSIZE))
600 /* Buffer overflow, ignore char */
603 c = &((struct atmel_uart_char *)ring->buf)[ring->head];
607 /* Make sure the character is stored before we update head. */
610 ring->head = (ring->head + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
614 * Deal with parity, framing and overrun errors.
616 static void atmel_pdc_rxerr(struct uart_port *port, unsigned int status)
619 UART_PUT_CR(port, ATMEL_US_RSTSTA);
621 if (status & ATMEL_US_RXBRK) {
622 /* ignore side-effect */
623 status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
626 if (status & ATMEL_US_PARE)
627 port->icount.parity++;
628 if (status & ATMEL_US_FRAME)
629 port->icount.frame++;
630 if (status & ATMEL_US_OVRE)
631 port->icount.overrun++;
635 * Characters received (called from interrupt handler)
637 static void atmel_rx_chars(struct uart_port *port)
639 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
640 unsigned int status, ch;
642 status = UART_GET_CSR(port);
643 while (status & ATMEL_US_RXRDY) {
644 ch = UART_GET_CHAR(port);
647 * note that the error handling code is
648 * out of the main execution path
650 if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
651 | ATMEL_US_OVRE | ATMEL_US_RXBRK)
652 || atmel_port->break_active)) {
655 UART_PUT_CR(port, ATMEL_US_RSTSTA);
657 if (status & ATMEL_US_RXBRK
658 && !atmel_port->break_active) {
659 atmel_port->break_active = 1;
660 UART_PUT_IER(port, ATMEL_US_RXBRK);
663 * This is either the end-of-break
664 * condition or we've received at
665 * least one character without RXBRK
666 * being set. In both cases, the next
667 * RXBRK will indicate start-of-break.
669 UART_PUT_IDR(port, ATMEL_US_RXBRK);
670 status &= ~ATMEL_US_RXBRK;
671 atmel_port->break_active = 0;
675 atmel_buffer_rx_char(port, status, ch);
676 status = UART_GET_CSR(port);
679 tasklet_schedule(&atmel_port->tasklet);
683 * Transmit characters (called from tasklet with TXRDY interrupt
686 static void atmel_tx_chars(struct uart_port *port)
688 struct circ_buf *xmit = &port->state->xmit;
689 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
691 if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) {
692 UART_PUT_CHAR(port, port->x_char);
696 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
699 while (UART_GET_CSR(port) & atmel_port->tx_done_mask) {
700 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
701 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
703 if (uart_circ_empty(xmit))
707 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
708 uart_write_wakeup(port);
710 if (!uart_circ_empty(xmit))
711 /* Enable interrupts */
712 UART_PUT_IER(port, atmel_port->tx_done_mask);
715 static void atmel_complete_tx_dma(void *arg)
717 struct atmel_uart_port *atmel_port = arg;
718 struct uart_port *port = &atmel_port->uart;
719 struct circ_buf *xmit = &port->state->xmit;
720 struct dma_chan *chan = atmel_port->chan_tx;
723 spin_lock_irqsave(&port->lock, flags);
726 dmaengine_terminate_all(chan);
727 xmit->tail += sg_dma_len(&atmel_port->sg_tx);
728 xmit->tail &= UART_XMIT_SIZE - 1;
730 port->icount.tx += sg_dma_len(&atmel_port->sg_tx);
732 spin_lock_irq(&atmel_port->lock_tx);
733 async_tx_ack(atmel_port->desc_tx);
734 atmel_port->cookie_tx = -EINVAL;
735 atmel_port->desc_tx = NULL;
736 spin_unlock_irq(&atmel_port->lock_tx);
738 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
739 uart_write_wakeup(port);
742 * xmit is a circular buffer so, if we have just send data from
743 * xmit->tail to the end of xmit->buf, now we have to transmit the
744 * remaining data from the beginning of xmit->buf to xmit->head.
746 if (!uart_circ_empty(xmit))
747 tasklet_schedule(&atmel_port->tasklet);
749 spin_unlock_irqrestore(&port->lock, flags);
752 static void atmel_release_tx_dma(struct uart_port *port)
754 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
755 struct dma_chan *chan = atmel_port->chan_tx;
758 dmaengine_terminate_all(chan);
759 dma_release_channel(chan);
760 dma_unmap_sg(port->dev, &atmel_port->sg_tx, 1,
764 atmel_port->desc_tx = NULL;
765 atmel_port->chan_tx = NULL;
766 atmel_port->cookie_tx = -EINVAL;
770 * Called from tasklet with TXRDY interrupt is disabled.
772 static void atmel_tx_dma(struct uart_port *port)
774 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
775 struct circ_buf *xmit = &port->state->xmit;
776 struct dma_chan *chan = atmel_port->chan_tx;
777 struct dma_async_tx_descriptor *desc;
778 struct scatterlist *sg = &atmel_port->sg_tx;
780 /* Make sure we have an idle channel */
781 if (atmel_port->desc_tx != NULL)
784 if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
787 * Port xmit buffer is already mapped,
788 * and it is one page... Just adjust
789 * offsets and lengths. Since it is a circular buffer,
790 * we have to transmit till the end, and then the rest.
791 * Take the port lock to get a
792 * consistent xmit buffer state.
794 sg->offset = xmit->tail & (UART_XMIT_SIZE - 1);
795 sg_dma_address(sg) = (sg_dma_address(sg) &
796 ~(UART_XMIT_SIZE - 1))
798 sg_dma_len(sg) = CIRC_CNT_TO_END(xmit->head,
801 BUG_ON(!sg_dma_len(sg));
803 desc = dmaengine_prep_slave_sg(chan,
810 dev_err(port->dev, "Failed to send via dma!\n");
814 dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);
816 atmel_port->desc_tx = desc;
817 desc->callback = atmel_complete_tx_dma;
818 desc->callback_param = atmel_port;
819 atmel_port->cookie_tx = dmaengine_submit(desc);
822 if (port->rs485.flags & SER_RS485_ENABLED) {
823 /* DMA done, stop TX, start RX for RS485 */
824 atmel_start_rx(port);
828 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
829 uart_write_wakeup(port);
832 static int atmel_prepare_tx_dma(struct uart_port *port)
834 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
836 struct dma_slave_config config;
840 dma_cap_set(DMA_SLAVE, mask);
842 atmel_port->chan_tx = dma_request_slave_channel(port->dev, "tx");
843 if (atmel_port->chan_tx == NULL)
845 dev_info(port->dev, "using %s for tx DMA transfers\n",
846 dma_chan_name(atmel_port->chan_tx));
848 spin_lock_init(&atmel_port->lock_tx);
849 sg_init_table(&atmel_port->sg_tx, 1);
850 /* UART circular tx buffer is an aligned page. */
851 BUG_ON(!PAGE_ALIGNED(port->state->xmit.buf));
852 sg_set_page(&atmel_port->sg_tx,
853 virt_to_page(port->state->xmit.buf),
855 (int)port->state->xmit.buf & ~PAGE_MASK);
856 nent = dma_map_sg(port->dev,
862 dev_dbg(port->dev, "need to release resource of dma\n");
865 dev_dbg(port->dev, "%s: mapped %d@%p to %x\n", __func__,
866 sg_dma_len(&atmel_port->sg_tx),
867 port->state->xmit.buf,
868 sg_dma_address(&atmel_port->sg_tx));
871 /* Configure the slave DMA */
872 memset(&config, 0, sizeof(config));
873 config.direction = DMA_MEM_TO_DEV;
874 config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
875 config.dst_addr = port->mapbase + ATMEL_US_THR;
877 ret = dmaengine_slave_config(atmel_port->chan_tx,
880 dev_err(port->dev, "DMA tx slave configuration failed\n");
887 dev_err(port->dev, "TX channel not available, switch to pio\n");
888 atmel_port->use_dma_tx = 0;
889 if (atmel_port->chan_tx)
890 atmel_release_tx_dma(port);
894 static void atmel_complete_rx_dma(void *arg)
896 struct uart_port *port = arg;
897 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
899 tasklet_schedule(&atmel_port->tasklet);
902 static void atmel_release_rx_dma(struct uart_port *port)
904 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
905 struct dma_chan *chan = atmel_port->chan_rx;
908 dmaengine_terminate_all(chan);
909 dma_release_channel(chan);
910 dma_unmap_sg(port->dev, &atmel_port->sg_rx, 1,
914 atmel_port->desc_rx = NULL;
915 atmel_port->chan_rx = NULL;
916 atmel_port->cookie_rx = -EINVAL;
919 static void atmel_rx_from_dma(struct uart_port *port)
921 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
922 struct tty_port *tport = &port->state->port;
923 struct circ_buf *ring = &atmel_port->rx_ring;
924 struct dma_chan *chan = atmel_port->chan_rx;
925 struct dma_tx_state state;
926 enum dma_status dmastat;
930 /* Reset the UART timeout early so that we don't miss one */
931 UART_PUT_CR(port, ATMEL_US_STTTO);
932 dmastat = dmaengine_tx_status(chan,
933 atmel_port->cookie_rx,
935 /* Restart a new tasklet if DMA status is error */
936 if (dmastat == DMA_ERROR) {
937 dev_dbg(port->dev, "Get residue error, restart tasklet\n");
938 UART_PUT_IER(port, ATMEL_US_TIMEOUT);
939 tasklet_schedule(&atmel_port->tasklet);
943 /* CPU claims ownership of RX DMA buffer */
944 dma_sync_sg_for_cpu(port->dev,
950 * ring->head points to the end of data already written by the DMA.
951 * ring->tail points to the beginning of data to be read by the
953 * The current transfer size should not be larger than the dma buffer
956 ring->head = sg_dma_len(&atmel_port->sg_rx) - state.residue;
957 BUG_ON(ring->head > sg_dma_len(&atmel_port->sg_rx));
959 * At this point ring->head may point to the first byte right after the
960 * last byte of the dma buffer:
961 * 0 <= ring->head <= sg_dma_len(&atmel_port->sg_rx)
963 * However ring->tail must always points inside the dma buffer:
964 * 0 <= ring->tail <= sg_dma_len(&atmel_port->sg_rx) - 1
966 * Since we use a ring buffer, we have to handle the case
967 * where head is lower than tail. In such a case, we first read from
968 * tail to the end of the buffer then reset tail.
970 if (ring->head < ring->tail) {
971 count = sg_dma_len(&atmel_port->sg_rx) - ring->tail;
973 tty_insert_flip_string(tport, ring->buf + ring->tail, count);
975 port->icount.rx += count;
978 /* Finally we read data from tail to head */
979 if (ring->tail < ring->head) {
980 count = ring->head - ring->tail;
982 tty_insert_flip_string(tport, ring->buf + ring->tail, count);
983 /* Wrap ring->head if needed */
984 if (ring->head >= sg_dma_len(&atmel_port->sg_rx))
986 ring->tail = ring->head;
987 port->icount.rx += count;
990 /* USART retreives ownership of RX DMA buffer */
991 dma_sync_sg_for_device(port->dev,
997 * Drop the lock here since it might end up calling
998 * uart_start(), which takes the lock.
1000 spin_unlock(&port->lock);
1001 tty_flip_buffer_push(tport);
1002 spin_lock(&port->lock);
1004 UART_PUT_IER(port, ATMEL_US_TIMEOUT);
1007 static int atmel_prepare_rx_dma(struct uart_port *port)
1009 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1010 struct dma_async_tx_descriptor *desc;
1011 dma_cap_mask_t mask;
1012 struct dma_slave_config config;
1013 struct circ_buf *ring;
1016 ring = &atmel_port->rx_ring;
1019 dma_cap_set(DMA_CYCLIC, mask);
1021 atmel_port->chan_rx = dma_request_slave_channel(port->dev, "rx");
1022 if (atmel_port->chan_rx == NULL)
1024 dev_info(port->dev, "using %s for rx DMA transfers\n",
1025 dma_chan_name(atmel_port->chan_rx));
1027 spin_lock_init(&atmel_port->lock_rx);
1028 sg_init_table(&atmel_port->sg_rx, 1);
1029 /* UART circular rx buffer is an aligned page. */
1030 BUG_ON(!PAGE_ALIGNED(ring->buf));
1031 sg_set_page(&atmel_port->sg_rx,
1032 virt_to_page(ring->buf),
1033 sizeof(struct atmel_uart_char) * ATMEL_SERIAL_RINGSIZE,
1034 (int)ring->buf & ~PAGE_MASK);
1035 nent = dma_map_sg(port->dev,
1041 dev_dbg(port->dev, "need to release resource of dma\n");
1044 dev_dbg(port->dev, "%s: mapped %d@%p to %x\n", __func__,
1045 sg_dma_len(&atmel_port->sg_rx),
1047 sg_dma_address(&atmel_port->sg_rx));
1050 /* Configure the slave DMA */
1051 memset(&config, 0, sizeof(config));
1052 config.direction = DMA_DEV_TO_MEM;
1053 config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1054 config.src_addr = port->mapbase + ATMEL_US_RHR;
1056 ret = dmaengine_slave_config(atmel_port->chan_rx,
1059 dev_err(port->dev, "DMA rx slave configuration failed\n");
1063 * Prepare a cyclic dma transfer, assign 2 descriptors,
1064 * each one is half ring buffer size
1066 desc = dmaengine_prep_dma_cyclic(atmel_port->chan_rx,
1067 sg_dma_address(&atmel_port->sg_rx),
1068 sg_dma_len(&atmel_port->sg_rx),
1069 sg_dma_len(&atmel_port->sg_rx)/2,
1071 DMA_PREP_INTERRUPT);
1072 desc->callback = atmel_complete_rx_dma;
1073 desc->callback_param = port;
1074 atmel_port->desc_rx = desc;
1075 atmel_port->cookie_rx = dmaengine_submit(desc);
1080 dev_err(port->dev, "RX channel not available, switch to pio\n");
1081 atmel_port->use_dma_rx = 0;
1082 if (atmel_port->chan_rx)
1083 atmel_release_rx_dma(port);
1087 static void atmel_uart_timer_callback(unsigned long data)
1089 struct uart_port *port = (void *)data;
1090 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1092 tasklet_schedule(&atmel_port->tasklet);
1093 mod_timer(&atmel_port->uart_timer, jiffies + uart_poll_timeout(port));
1097 * receive interrupt handler.
1100 atmel_handle_receive(struct uart_port *port, unsigned int pending)
1102 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1104 if (atmel_use_pdc_rx(port)) {
1106 * PDC receive. Just schedule the tasklet and let it
1107 * figure out the details.
1109 * TODO: We're not handling error flags correctly at
1112 if (pending & (ATMEL_US_ENDRX | ATMEL_US_TIMEOUT)) {
1113 UART_PUT_IDR(port, (ATMEL_US_ENDRX
1114 | ATMEL_US_TIMEOUT));
1115 tasklet_schedule(&atmel_port->tasklet);
1118 if (pending & (ATMEL_US_RXBRK | ATMEL_US_OVRE |
1119 ATMEL_US_FRAME | ATMEL_US_PARE))
1120 atmel_pdc_rxerr(port, pending);
1123 if (atmel_use_dma_rx(port)) {
1124 if (pending & ATMEL_US_TIMEOUT) {
1125 UART_PUT_IDR(port, ATMEL_US_TIMEOUT);
1126 tasklet_schedule(&atmel_port->tasklet);
1130 /* Interrupt receive */
1131 if (pending & ATMEL_US_RXRDY)
1132 atmel_rx_chars(port);
1133 else if (pending & ATMEL_US_RXBRK) {
1135 * End of break detected. If it came along with a
1136 * character, atmel_rx_chars will handle it.
1138 UART_PUT_CR(port, ATMEL_US_RSTSTA);
1139 UART_PUT_IDR(port, ATMEL_US_RXBRK);
1140 atmel_port->break_active = 0;
1145 * transmit interrupt handler. (Transmit is IRQF_NODELAY safe)
1148 atmel_handle_transmit(struct uart_port *port, unsigned int pending)
1150 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1152 if (pending & atmel_port->tx_done_mask) {
1153 /* Either PDC or interrupt transmission */
1154 UART_PUT_IDR(port, atmel_port->tx_done_mask);
1155 tasklet_schedule(&atmel_port->tasklet);
1160 * status flags interrupt handler.
1163 atmel_handle_status(struct uart_port *port, unsigned int pending,
1164 unsigned int status)
1166 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1168 if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC
1169 | ATMEL_US_CTSIC)) {
1170 atmel_port->irq_status = status;
1171 tasklet_schedule(&atmel_port->tasklet);
1178 static irqreturn_t atmel_interrupt(int irq, void *dev_id)
1180 struct uart_port *port = dev_id;
1181 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1182 unsigned int status, pending, pass_counter = 0;
1183 bool gpio_handled = false;
1186 status = atmel_get_lines_status(port);
1187 pending = status & UART_GET_IMR(port);
1188 if (!gpio_handled) {
1190 * Dealing with GPIO interrupt
1192 if (irq == atmel_port->gpio_irq[UART_GPIO_CTS])
1193 pending |= ATMEL_US_CTSIC;
1195 if (irq == atmel_port->gpio_irq[UART_GPIO_DSR])
1196 pending |= ATMEL_US_DSRIC;
1198 if (irq == atmel_port->gpio_irq[UART_GPIO_RI])
1199 pending |= ATMEL_US_RIIC;
1201 if (irq == atmel_port->gpio_irq[UART_GPIO_DCD])
1202 pending |= ATMEL_US_DCDIC;
1204 gpio_handled = true;
1209 atmel_handle_receive(port, pending);
1210 atmel_handle_status(port, pending, status);
1211 atmel_handle_transmit(port, pending);
1212 } while (pass_counter++ < ATMEL_ISR_PASS_LIMIT);
1214 return pass_counter ? IRQ_HANDLED : IRQ_NONE;
1217 static void atmel_release_tx_pdc(struct uart_port *port)
1219 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1220 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
1222 dma_unmap_single(port->dev,
1229 * Called from tasklet with ENDTX and TXBUFE interrupts disabled.
1231 static void atmel_tx_pdc(struct uart_port *port)
1233 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1234 struct circ_buf *xmit = &port->state->xmit;
1235 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
1238 /* nothing left to transmit? */
1239 if (UART_GET_TCR(port))
1242 xmit->tail += pdc->ofs;
1243 xmit->tail &= UART_XMIT_SIZE - 1;
1245 port->icount.tx += pdc->ofs;
1248 /* more to transmit - setup next transfer */
1250 /* disable PDC transmit */
1251 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
1253 if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
1254 dma_sync_single_for_device(port->dev,
1259 count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
1262 UART_PUT_TPR(port, pdc->dma_addr + xmit->tail);
1263 UART_PUT_TCR(port, count);
1264 /* re-enable PDC transmit */
1265 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
1266 /* Enable interrupts */
1267 UART_PUT_IER(port, atmel_port->tx_done_mask);
1269 if ((port->rs485.flags & SER_RS485_ENABLED) &&
1270 !(port->rs485.flags & SER_RS485_RX_DURING_TX)) {
1271 /* DMA done, stop TX, start RX for RS485 */
1272 atmel_start_rx(port);
1276 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1277 uart_write_wakeup(port);
1280 static int atmel_prepare_tx_pdc(struct uart_port *port)
1282 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1283 struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
1284 struct circ_buf *xmit = &port->state->xmit;
1286 pdc->buf = xmit->buf;
1287 pdc->dma_addr = dma_map_single(port->dev,
1291 pdc->dma_size = UART_XMIT_SIZE;
1297 static void atmel_rx_from_ring(struct uart_port *port)
1299 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1300 struct circ_buf *ring = &atmel_port->rx_ring;
1302 unsigned int status;
1304 while (ring->head != ring->tail) {
1305 struct atmel_uart_char c;
1307 /* Make sure c is loaded after head. */
1310 c = ((struct atmel_uart_char *)ring->buf)[ring->tail];
1312 ring->tail = (ring->tail + 1) & (ATMEL_SERIAL_RINGSIZE - 1);
1319 * note that the error handling code is
1320 * out of the main execution path
1322 if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
1323 | ATMEL_US_OVRE | ATMEL_US_RXBRK))) {
1324 if (status & ATMEL_US_RXBRK) {
1325 /* ignore side-effect */
1326 status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);
1329 if (uart_handle_break(port))
1332 if (status & ATMEL_US_PARE)
1333 port->icount.parity++;
1334 if (status & ATMEL_US_FRAME)
1335 port->icount.frame++;
1336 if (status & ATMEL_US_OVRE)
1337 port->icount.overrun++;
1339 status &= port->read_status_mask;
1341 if (status & ATMEL_US_RXBRK)
1343 else if (status & ATMEL_US_PARE)
1345 else if (status & ATMEL_US_FRAME)
1350 if (uart_handle_sysrq_char(port, c.ch))
1353 uart_insert_char(port, status, ATMEL_US_OVRE, c.ch, flg);
1357 * Drop the lock here since it might end up calling
1358 * uart_start(), which takes the lock.
1360 spin_unlock(&port->lock);
1361 tty_flip_buffer_push(&port->state->port);
1362 spin_lock(&port->lock);
1365 static void atmel_release_rx_pdc(struct uart_port *port)
1367 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1370 for (i = 0; i < 2; i++) {
1371 struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
1373 dma_unmap_single(port->dev,
1381 static void atmel_rx_from_pdc(struct uart_port *port)
1383 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1384 struct tty_port *tport = &port->state->port;
1385 struct atmel_dma_buffer *pdc;
1386 int rx_idx = atmel_port->pdc_rx_idx;
1392 /* Reset the UART timeout early so that we don't miss one */
1393 UART_PUT_CR(port, ATMEL_US_STTTO);
1395 pdc = &atmel_port->pdc_rx[rx_idx];
1396 head = UART_GET_RPR(port) - pdc->dma_addr;
1399 /* If the PDC has switched buffers, RPR won't contain
1400 * any address within the current buffer. Since head
1401 * is unsigned, we just need a one-way comparison to
1404 * In this case, we just need to consume the entire
1405 * buffer and resubmit it for DMA. This will clear the
1406 * ENDRX bit as well, so that we can safely re-enable
1407 * all interrupts below.
1409 head = min(head, pdc->dma_size);
1411 if (likely(head != tail)) {
1412 dma_sync_single_for_cpu(port->dev, pdc->dma_addr,
1413 pdc->dma_size, DMA_FROM_DEVICE);
1416 * head will only wrap around when we recycle
1417 * the DMA buffer, and when that happens, we
1418 * explicitly set tail to 0. So head will
1419 * always be greater than tail.
1421 count = head - tail;
1423 tty_insert_flip_string(tport, pdc->buf + pdc->ofs,
1426 dma_sync_single_for_device(port->dev, pdc->dma_addr,
1427 pdc->dma_size, DMA_FROM_DEVICE);
1429 port->icount.rx += count;
1434 * If the current buffer is full, we need to check if
1435 * the next one contains any additional data.
1437 if (head >= pdc->dma_size) {
1439 UART_PUT_RNPR(port, pdc->dma_addr);
1440 UART_PUT_RNCR(port, pdc->dma_size);
1443 atmel_port->pdc_rx_idx = rx_idx;
1445 } while (head >= pdc->dma_size);
1448 * Drop the lock here since it might end up calling
1449 * uart_start(), which takes the lock.
1451 spin_unlock(&port->lock);
1452 tty_flip_buffer_push(tport);
1453 spin_lock(&port->lock);
1455 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
1458 static int atmel_prepare_rx_pdc(struct uart_port *port)
1460 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1463 for (i = 0; i < 2; i++) {
1464 struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];
1466 pdc->buf = kmalloc(PDC_BUFFER_SIZE, GFP_KERNEL);
1467 if (pdc->buf == NULL) {
1469 dma_unmap_single(port->dev,
1470 atmel_port->pdc_rx[0].dma_addr,
1473 kfree(atmel_port->pdc_rx[0].buf);
1475 atmel_port->use_pdc_rx = 0;
1478 pdc->dma_addr = dma_map_single(port->dev,
1482 pdc->dma_size = PDC_BUFFER_SIZE;
1486 atmel_port->pdc_rx_idx = 0;
1488 UART_PUT_RPR(port, atmel_port->pdc_rx[0].dma_addr);
1489 UART_PUT_RCR(port, PDC_BUFFER_SIZE);
1491 UART_PUT_RNPR(port, atmel_port->pdc_rx[1].dma_addr);
1492 UART_PUT_RNCR(port, PDC_BUFFER_SIZE);
1498 * tasklet handling tty stuff outside the interrupt handler.
1500 static void atmel_tasklet_func(unsigned long data)
1502 struct uart_port *port = (struct uart_port *)data;
1503 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1504 unsigned int status;
1505 unsigned int status_change;
1507 /* The interrupt handler does not take the lock */
1508 spin_lock(&port->lock);
1510 atmel_port->schedule_tx(port);
1512 status = atmel_port->irq_status;
1513 status_change = status ^ atmel_port->irq_status_prev;
1515 if (status_change & (ATMEL_US_RI | ATMEL_US_DSR
1516 | ATMEL_US_DCD | ATMEL_US_CTS)) {
1517 /* TODO: All reads to CSR will clear these interrupts! */
1518 if (status_change & ATMEL_US_RI)
1520 if (status_change & ATMEL_US_DSR)
1522 if (status_change & ATMEL_US_DCD)
1523 uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
1524 if (status_change & ATMEL_US_CTS)
1525 uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
1527 wake_up_interruptible(&port->state->port.delta_msr_wait);
1529 atmel_port->irq_status_prev = status;
1532 atmel_port->schedule_rx(port);
1534 spin_unlock(&port->lock);
1537 static void atmel_init_property(struct atmel_uart_port *atmel_port,
1538 struct platform_device *pdev)
1540 struct device_node *np = pdev->dev.of_node;
1541 struct atmel_uart_data *pdata = dev_get_platdata(&pdev->dev);
1544 /* DMA/PDC usage specification */
1545 if (of_get_property(np, "atmel,use-dma-rx", NULL)) {
1546 if (of_get_property(np, "dmas", NULL)) {
1547 atmel_port->use_dma_rx = true;
1548 atmel_port->use_pdc_rx = false;
1550 atmel_port->use_dma_rx = false;
1551 atmel_port->use_pdc_rx = true;
1554 atmel_port->use_dma_rx = false;
1555 atmel_port->use_pdc_rx = false;
1558 if (of_get_property(np, "atmel,use-dma-tx", NULL)) {
1559 if (of_get_property(np, "dmas", NULL)) {
1560 atmel_port->use_dma_tx = true;
1561 atmel_port->use_pdc_tx = false;
1563 atmel_port->use_dma_tx = false;
1564 atmel_port->use_pdc_tx = true;
1567 atmel_port->use_dma_tx = false;
1568 atmel_port->use_pdc_tx = false;
1572 atmel_port->use_pdc_rx = pdata->use_dma_rx;
1573 atmel_port->use_pdc_tx = pdata->use_dma_tx;
1574 atmel_port->use_dma_rx = false;
1575 atmel_port->use_dma_tx = false;
1580 static void atmel_init_rs485(struct uart_port *port,
1581 struct platform_device *pdev)
1583 struct device_node *np = pdev->dev.of_node;
1584 struct atmel_uart_data *pdata = dev_get_platdata(&pdev->dev);
1588 /* rs485 properties */
1589 if (of_property_read_u32_array(np, "rs485-rts-delay",
1590 rs485_delay, 2) == 0) {
1591 struct serial_rs485 *rs485conf = &port->rs485;
1593 rs485conf->delay_rts_before_send = rs485_delay[0];
1594 rs485conf->delay_rts_after_send = rs485_delay[1];
1595 rs485conf->flags = 0;
1597 if (of_get_property(np, "rs485-rx-during-tx", NULL))
1598 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1600 if (of_get_property(np, "linux,rs485-enabled-at-boot-time",
1602 rs485conf->flags |= SER_RS485_ENABLED;
1605 port->rs485 = pdata->rs485;
1610 static void atmel_set_ops(struct uart_port *port)
1612 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1614 if (atmel_use_dma_rx(port)) {
1615 atmel_port->prepare_rx = &atmel_prepare_rx_dma;
1616 atmel_port->schedule_rx = &atmel_rx_from_dma;
1617 atmel_port->release_rx = &atmel_release_rx_dma;
1618 } else if (atmel_use_pdc_rx(port)) {
1619 atmel_port->prepare_rx = &atmel_prepare_rx_pdc;
1620 atmel_port->schedule_rx = &atmel_rx_from_pdc;
1621 atmel_port->release_rx = &atmel_release_rx_pdc;
1623 atmel_port->prepare_rx = NULL;
1624 atmel_port->schedule_rx = &atmel_rx_from_ring;
1625 atmel_port->release_rx = NULL;
1628 if (atmel_use_dma_tx(port)) {
1629 atmel_port->prepare_tx = &atmel_prepare_tx_dma;
1630 atmel_port->schedule_tx = &atmel_tx_dma;
1631 atmel_port->release_tx = &atmel_release_tx_dma;
1632 } else if (atmel_use_pdc_tx(port)) {
1633 atmel_port->prepare_tx = &atmel_prepare_tx_pdc;
1634 atmel_port->schedule_tx = &atmel_tx_pdc;
1635 atmel_port->release_tx = &atmel_release_tx_pdc;
1637 atmel_port->prepare_tx = NULL;
1638 atmel_port->schedule_tx = &atmel_tx_chars;
1639 atmel_port->release_tx = NULL;
1644 * Get ip name usart or uart
1646 static void atmel_get_ip_name(struct uart_port *port)
1648 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1649 int name = UART_GET_IP_NAME(port);
1652 /* usart and uart ascii */
1656 atmel_port->is_usart = false;
1658 if (name == usart) {
1659 dev_dbg(port->dev, "This is usart\n");
1660 atmel_port->is_usart = true;
1661 } else if (name == uart) {
1662 dev_dbg(port->dev, "This is uart\n");
1663 atmel_port->is_usart = false;
1665 /* fallback for older SoCs: use version field */
1666 version = UART_GET_IP_VERSION(port);
1670 dev_dbg(port->dev, "This version is usart\n");
1671 atmel_port->is_usart = true;
1675 dev_dbg(port->dev, "This version is uart\n");
1676 atmel_port->is_usart = false;
1679 dev_err(port->dev, "Not supported ip name nor version, set to uart\n");
1684 static void atmel_free_gpio_irq(struct uart_port *port)
1686 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1687 enum mctrl_gpio_idx i;
1689 for (i = 0; i < UART_GPIO_MAX; i++)
1690 if (atmel_port->gpio_irq[i] >= 0)
1691 free_irq(atmel_port->gpio_irq[i], port);
1694 static int atmel_request_gpio_irq(struct uart_port *port)
1696 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1697 int *irq = atmel_port->gpio_irq;
1698 enum mctrl_gpio_idx i;
1701 for (i = 0; (i < UART_GPIO_MAX) && !err; i++) {
1705 irq_set_status_flags(irq[i], IRQ_NOAUTOEN);
1706 err = request_irq(irq[i], atmel_interrupt, IRQ_TYPE_EDGE_BOTH,
1707 "atmel_serial", port);
1709 dev_err(port->dev, "atmel_startup - Can't get %d irq\n",
1714 * If something went wrong, rollback.
1716 while (err && (--i >= 0))
1718 free_irq(irq[i], port);
1724 * Perform initialization and enable port for reception
1726 static int atmel_startup(struct uart_port *port)
1728 struct platform_device *pdev = to_platform_device(port->dev);
1729 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1730 struct tty_struct *tty = port->state->port.tty;
1734 * Ensure that no interrupts are enabled otherwise when
1735 * request_irq() is called we could get stuck trying to
1736 * handle an unexpected interrupt
1738 UART_PUT_IDR(port, -1);
1739 atmel_port->ms_irq_enabled = false;
1744 retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED,
1745 tty ? tty->name : "atmel_serial", port);
1747 dev_err(port->dev, "atmel_startup - Can't get irq\n");
1752 * Get the GPIO lines IRQ
1754 retval = atmel_request_gpio_irq(port);
1758 tasklet_enable(&atmel_port->tasklet);
1761 * Initialize DMA (if necessary)
1763 atmel_init_property(atmel_port, pdev);
1764 atmel_set_ops(port);
1766 if (atmel_port->prepare_rx) {
1767 retval = atmel_port->prepare_rx(port);
1769 atmel_set_ops(port);
1772 if (atmel_port->prepare_tx) {
1773 retval = atmel_port->prepare_tx(port);
1775 atmel_set_ops(port);
1778 /* Save current CSR for comparison in atmel_tasklet_func() */
1779 atmel_port->irq_status_prev = atmel_get_lines_status(port);
1780 atmel_port->irq_status = atmel_port->irq_status_prev;
1783 * Finally, enable the serial port
1785 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
1786 /* enable xmit & rcvr */
1787 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
1789 setup_timer(&atmel_port->uart_timer,
1790 atmel_uart_timer_callback,
1791 (unsigned long)port);
1793 if (atmel_use_pdc_rx(port)) {
1794 /* set UART timeout */
1795 if (!atmel_port->is_usart) {
1796 mod_timer(&atmel_port->uart_timer,
1797 jiffies + uart_poll_timeout(port));
1798 /* set USART timeout */
1800 UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
1801 UART_PUT_CR(port, ATMEL_US_STTTO);
1803 UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
1805 /* enable PDC controller */
1806 UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
1807 } else if (atmel_use_dma_rx(port)) {
1808 /* set UART timeout */
1809 if (!atmel_port->is_usart) {
1810 mod_timer(&atmel_port->uart_timer,
1811 jiffies + uart_poll_timeout(port));
1812 /* set USART timeout */
1814 UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
1815 UART_PUT_CR(port, ATMEL_US_STTTO);
1817 UART_PUT_IER(port, ATMEL_US_TIMEOUT);
1820 /* enable receive only */
1821 UART_PUT_IER(port, ATMEL_US_RXRDY);
1827 free_irq(port->irq, port);
1833 * Flush any TX data submitted for DMA. Called when the TX circular
1836 static void atmel_flush_buffer(struct uart_port *port)
1838 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1840 if (atmel_use_pdc_tx(port)) {
1841 UART_PUT_TCR(port, 0);
1842 atmel_port->pdc_tx.ofs = 0;
1849 static void atmel_shutdown(struct uart_port *port)
1851 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1854 * Prevent any tasklets being scheduled during
1857 del_timer_sync(&atmel_port->uart_timer);
1860 * Clear out any scheduled tasklets before
1861 * we destroy the buffers
1863 tasklet_disable(&atmel_port->tasklet);
1864 tasklet_kill(&atmel_port->tasklet);
1867 * Ensure everything is stopped and
1868 * disable all interrupts, port and break condition.
1870 atmel_stop_rx(port);
1871 atmel_stop_tx(port);
1873 UART_PUT_CR(port, ATMEL_US_RSTSTA);
1874 UART_PUT_IDR(port, -1);
1878 * Shut-down the DMA.
1880 if (atmel_port->release_rx)
1881 atmel_port->release_rx(port);
1882 if (atmel_port->release_tx)
1883 atmel_port->release_tx(port);
1886 * Reset ring buffer pointers
1888 atmel_port->rx_ring.head = 0;
1889 atmel_port->rx_ring.tail = 0;
1892 * Free the interrupts
1894 free_irq(port->irq, port);
1895 atmel_free_gpio_irq(port);
1897 atmel_port->ms_irq_enabled = false;
1899 atmel_flush_buffer(port);
1903 * Power / Clock management.
1905 static void atmel_serial_pm(struct uart_port *port, unsigned int state,
1906 unsigned int oldstate)
1908 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
1913 * Enable the peripheral clock for this serial port.
1914 * This is called on uart_open() or a resume event.
1916 clk_prepare_enable(atmel_port->clk);
1918 /* re-enable interrupts if we disabled some on suspend */
1919 UART_PUT_IER(port, atmel_port->backup_imr);
1922 /* Back up the interrupt mask and disable all interrupts */
1923 atmel_port->backup_imr = UART_GET_IMR(port);
1924 UART_PUT_IDR(port, -1);
1927 * Disable the peripheral clock for this serial port.
1928 * This is called on uart_close() or a suspend event.
1930 clk_disable_unprepare(atmel_port->clk);
1933 dev_err(port->dev, "atmel_serial: unknown pm %d\n", state);
1938 * Change the port parameters
1940 static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
1941 struct ktermios *old)
1943 unsigned long flags;
1944 unsigned int old_mode, mode, imr, quot, baud;
1946 /* save the current mode register */
1947 mode = old_mode = UART_GET_MR(port);
1949 /* reset the mode, clock divisor, parity, stop bits and data size */
1950 mode &= ~(ATMEL_US_USCLKS | ATMEL_US_CHRL | ATMEL_US_NBSTOP |
1951 ATMEL_US_PAR | ATMEL_US_USMODE);
1953 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
1954 quot = uart_get_divisor(port, baud);
1956 if (quot > 65535) { /* BRGR is 16-bit, so switch to slower clock */
1958 mode |= ATMEL_US_USCLKS_MCK_DIV8;
1962 switch (termios->c_cflag & CSIZE) {
1964 mode |= ATMEL_US_CHRL_5;
1967 mode |= ATMEL_US_CHRL_6;
1970 mode |= ATMEL_US_CHRL_7;
1973 mode |= ATMEL_US_CHRL_8;
1978 if (termios->c_cflag & CSTOPB)
1979 mode |= ATMEL_US_NBSTOP_2;
1982 if (termios->c_cflag & PARENB) {
1983 /* Mark or Space parity */
1984 if (termios->c_cflag & CMSPAR) {
1985 if (termios->c_cflag & PARODD)
1986 mode |= ATMEL_US_PAR_MARK;
1988 mode |= ATMEL_US_PAR_SPACE;
1989 } else if (termios->c_cflag & PARODD)
1990 mode |= ATMEL_US_PAR_ODD;
1992 mode |= ATMEL_US_PAR_EVEN;
1994 mode |= ATMEL_US_PAR_NONE;
1996 spin_lock_irqsave(&port->lock, flags);
1998 port->read_status_mask = ATMEL_US_OVRE;
1999 if (termios->c_iflag & INPCK)
2000 port->read_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
2001 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
2002 port->read_status_mask |= ATMEL_US_RXBRK;
2004 if (atmel_use_pdc_rx(port))
2005 /* need to enable error interrupts */
2006 UART_PUT_IER(port, port->read_status_mask);
2009 * Characters to ignore
2011 port->ignore_status_mask = 0;
2012 if (termios->c_iflag & IGNPAR)
2013 port->ignore_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
2014 if (termios->c_iflag & IGNBRK) {
2015 port->ignore_status_mask |= ATMEL_US_RXBRK;
2017 * If we're ignoring parity and break indicators,
2018 * ignore overruns too (for real raw support).
2020 if (termios->c_iflag & IGNPAR)
2021 port->ignore_status_mask |= ATMEL_US_OVRE;
2023 /* TODO: Ignore all characters if CREAD is set.*/
2025 /* update the per-port timeout */
2026 uart_update_timeout(port, termios->c_cflag, baud);
2029 * save/disable interrupts. The tty layer will ensure that the
2030 * transmitter is empty if requested by the caller, so there's
2031 * no need to wait for it here.
2033 imr = UART_GET_IMR(port);
2034 UART_PUT_IDR(port, -1);
2036 /* disable receiver and transmitter */
2037 UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
2040 if (port->rs485.flags & SER_RS485_ENABLED) {
2041 if ((port->rs485.delay_rts_after_send) > 0)
2042 UART_PUT_TTGR(port, port->rs485.delay_rts_after_send);
2043 mode |= ATMEL_US_USMODE_RS485;
2044 } else if (termios->c_cflag & CRTSCTS) {
2045 /* RS232 with hardware handshake (RTS/CTS) */
2046 mode |= ATMEL_US_USMODE_HWHS;
2048 /* RS232 without hadware handshake */
2049 mode |= ATMEL_US_USMODE_NORMAL;
2052 /* set the mode, clock divisor, parity, stop bits and data size */
2053 UART_PUT_MR(port, mode);
2056 * when switching the mode, set the RTS line state according to the
2057 * new mode, otherwise keep the former state
2059 if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) {
2060 unsigned int rts_state;
2062 if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) {
2063 /* let the hardware control the RTS line */
2064 rts_state = ATMEL_US_RTSDIS;
2066 /* force RTS line to low level */
2067 rts_state = ATMEL_US_RTSEN;
2070 UART_PUT_CR(port, rts_state);
2073 /* set the baud rate */
2074 UART_PUT_BRGR(port, quot);
2075 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
2076 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
2078 /* restore interrupts */
2079 UART_PUT_IER(port, imr);
2081 /* CTS flow-control and modem-status interrupts */
2082 if (UART_ENABLE_MS(port, termios->c_cflag))
2083 atmel_enable_ms(port);
2085 atmel_disable_ms(port);
2087 spin_unlock_irqrestore(&port->lock, flags);
2090 static void atmel_set_ldisc(struct uart_port *port, struct ktermios *termios)
2092 if (termios->c_line == N_PPS) {
2093 port->flags |= UPF_HARDPPS_CD;
2094 spin_lock_irq(&port->lock);
2095 atmel_enable_ms(port);
2096 spin_unlock_irq(&port->lock);
2098 port->flags &= ~UPF_HARDPPS_CD;
2099 if (!UART_ENABLE_MS(port, termios->c_cflag)) {
2100 spin_lock_irq(&port->lock);
2101 atmel_disable_ms(port);
2102 spin_unlock_irq(&port->lock);
2108 * Return string describing the specified port
2110 static const char *atmel_type(struct uart_port *port)
2112 return (port->type == PORT_ATMEL) ? "ATMEL_SERIAL" : NULL;
2116 * Release the memory region(s) being used by 'port'.
2118 static void atmel_release_port(struct uart_port *port)
2120 struct platform_device *pdev = to_platform_device(port->dev);
2121 int size = pdev->resource[0].end - pdev->resource[0].start + 1;
2123 release_mem_region(port->mapbase, size);
2125 if (port->flags & UPF_IOREMAP) {
2126 iounmap(port->membase);
2127 port->membase = NULL;
2132 * Request the memory region(s) being used by 'port'.
2134 static int atmel_request_port(struct uart_port *port)
2136 struct platform_device *pdev = to_platform_device(port->dev);
2137 int size = pdev->resource[0].end - pdev->resource[0].start + 1;
2139 if (!request_mem_region(port->mapbase, size, "atmel_serial"))
2142 if (port->flags & UPF_IOREMAP) {
2143 port->membase = ioremap(port->mapbase, size);
2144 if (port->membase == NULL) {
2145 release_mem_region(port->mapbase, size);
2154 * Configure/autoconfigure the port.
2156 static void atmel_config_port(struct uart_port *port, int flags)
2158 if (flags & UART_CONFIG_TYPE) {
2159 port->type = PORT_ATMEL;
2160 atmel_request_port(port);
2165 * Verify the new serial_struct (for TIOCSSERIAL).
2167 static int atmel_verify_port(struct uart_port *port, struct serial_struct *ser)
2170 if (ser->type != PORT_UNKNOWN && ser->type != PORT_ATMEL)
2172 if (port->irq != ser->irq)
2174 if (ser->io_type != SERIAL_IO_MEM)
2176 if (port->uartclk / 16 != ser->baud_base)
2178 if ((void *)port->mapbase != ser->iomem_base)
2180 if (port->iobase != ser->port)
2187 #ifdef CONFIG_CONSOLE_POLL
2188 static int atmel_poll_get_char(struct uart_port *port)
2190 while (!(UART_GET_CSR(port) & ATMEL_US_RXRDY))
2193 return UART_GET_CHAR(port);
2196 static void atmel_poll_put_char(struct uart_port *port, unsigned char ch)
2198 while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
2201 UART_PUT_CHAR(port, ch);
2205 static struct uart_ops atmel_pops = {
2206 .tx_empty = atmel_tx_empty,
2207 .set_mctrl = atmel_set_mctrl,
2208 .get_mctrl = atmel_get_mctrl,
2209 .stop_tx = atmel_stop_tx,
2210 .start_tx = atmel_start_tx,
2211 .stop_rx = atmel_stop_rx,
2212 .enable_ms = atmel_enable_ms,
2213 .break_ctl = atmel_break_ctl,
2214 .startup = atmel_startup,
2215 .shutdown = atmel_shutdown,
2216 .flush_buffer = atmel_flush_buffer,
2217 .set_termios = atmel_set_termios,
2218 .set_ldisc = atmel_set_ldisc,
2220 .release_port = atmel_release_port,
2221 .request_port = atmel_request_port,
2222 .config_port = atmel_config_port,
2223 .verify_port = atmel_verify_port,
2224 .pm = atmel_serial_pm,
2225 #ifdef CONFIG_CONSOLE_POLL
2226 .poll_get_char = atmel_poll_get_char,
2227 .poll_put_char = atmel_poll_put_char,
2232 * Configure the port from the platform device resource info.
2234 static int atmel_init_port(struct atmel_uart_port *atmel_port,
2235 struct platform_device *pdev)
2238 struct uart_port *port = &atmel_port->uart;
2239 struct atmel_uart_data *pdata = dev_get_platdata(&pdev->dev);
2241 atmel_init_property(atmel_port, pdev);
2242 atmel_set_ops(port);
2244 atmel_init_rs485(port, pdev);
2246 port->iotype = UPIO_MEM;
2247 port->flags = UPF_BOOT_AUTOCONF;
2248 port->ops = &atmel_pops;
2250 port->dev = &pdev->dev;
2251 port->mapbase = pdev->resource[0].start;
2252 port->irq = pdev->resource[1].start;
2253 port->rs485_config = atmel_config_rs485;
2255 tasklet_init(&atmel_port->tasklet, atmel_tasklet_func,
2256 (unsigned long)port);
2257 tasklet_disable(&atmel_port->tasklet);
2259 memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
2261 if (pdata && pdata->regs) {
2262 /* Already mapped by setup code */
2263 port->membase = pdata->regs;
2265 port->flags |= UPF_IOREMAP;
2266 port->membase = NULL;
2269 /* for console, the clock could already be configured */
2270 if (!atmel_port->clk) {
2271 atmel_port->clk = clk_get(&pdev->dev, "usart");
2272 if (IS_ERR(atmel_port->clk)) {
2273 ret = PTR_ERR(atmel_port->clk);
2274 atmel_port->clk = NULL;
2277 ret = clk_prepare_enable(atmel_port->clk);
2279 clk_put(atmel_port->clk);
2280 atmel_port->clk = NULL;
2283 port->uartclk = clk_get_rate(atmel_port->clk);
2284 clk_disable_unprepare(atmel_port->clk);
2285 /* only enable clock when USART is in use */
2288 /* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
2289 if (port->rs485.flags & SER_RS485_ENABLED)
2290 atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
2291 else if (atmel_use_pdc_tx(port)) {
2292 port->fifosize = PDC_BUFFER_SIZE;
2293 atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE;
2295 atmel_port->tx_done_mask = ATMEL_US_TXRDY;
2301 struct platform_device *atmel_default_console_device; /* the serial console device */
2303 #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
2304 static void atmel_console_putchar(struct uart_port *port, int ch)
2306 while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
2308 UART_PUT_CHAR(port, ch);
2312 * Interrupts are disabled on entering
2314 static void atmel_console_write(struct console *co, const char *s, u_int count)
2316 struct uart_port *port = &atmel_ports[co->index].uart;
2317 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
2318 unsigned int status, imr;
2319 unsigned int pdc_tx;
2322 * First, save IMR and then disable interrupts
2324 imr = UART_GET_IMR(port);
2325 UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask);
2327 /* Store PDC transmit status and disable it */
2328 pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN;
2329 UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
2331 uart_console_write(port, s, count, atmel_console_putchar);
2334 * Finally, wait for transmitter to become empty
2338 status = UART_GET_CSR(port);
2339 } while (!(status & ATMEL_US_TXRDY));
2341 /* Restore PDC transmit status */
2343 UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
2345 /* set interrupts back the way they were */
2346 UART_PUT_IER(port, imr);
2350 * If the port was already initialised (eg, by a boot loader),
2351 * try to determine the current setup.
2353 static void __init atmel_console_get_options(struct uart_port *port, int *baud,
2354 int *parity, int *bits)
2356 unsigned int mr, quot;
2359 * If the baud rate generator isn't running, the port wasn't
2360 * initialized by the boot loader.
2362 quot = UART_GET_BRGR(port) & ATMEL_US_CD;
2366 mr = UART_GET_MR(port) & ATMEL_US_CHRL;
2367 if (mr == ATMEL_US_CHRL_8)
2372 mr = UART_GET_MR(port) & ATMEL_US_PAR;
2373 if (mr == ATMEL_US_PAR_EVEN)
2375 else if (mr == ATMEL_US_PAR_ODD)
2379 * The serial core only rounds down when matching this to a
2380 * supported baud rate. Make sure we don't end up slightly
2381 * lower than one of those, as it would make us fall through
2382 * to a much lower baud rate than we really want.
2384 *baud = port->uartclk / (16 * (quot - 1));
2387 static int __init atmel_console_setup(struct console *co, char *options)
2390 struct uart_port *port = &atmel_ports[co->index].uart;
2396 if (port->membase == NULL) {
2397 /* Port not initialized yet - delay setup */
2401 ret = clk_prepare_enable(atmel_ports[co->index].clk);
2405 UART_PUT_IDR(port, -1);
2406 UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
2407 UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
2410 uart_parse_options(options, &baud, &parity, &bits, &flow);
2412 atmel_console_get_options(port, &baud, &parity, &bits);
2414 return uart_set_options(port, co, baud, parity, bits, flow);
2417 static struct uart_driver atmel_uart;
2419 static struct console atmel_console = {
2420 .name = ATMEL_DEVICENAME,
2421 .write = atmel_console_write,
2422 .device = uart_console_device,
2423 .setup = atmel_console_setup,
2424 .flags = CON_PRINTBUFFER,
2426 .data = &atmel_uart,
2429 #define ATMEL_CONSOLE_DEVICE (&atmel_console)
2432 * Early console initialization (before VM subsystem initialized).
2434 static int __init atmel_console_init(void)
2437 if (atmel_default_console_device) {
2438 struct atmel_uart_data *pdata =
2439 dev_get_platdata(&atmel_default_console_device->dev);
2440 int id = pdata->num;
2441 struct atmel_uart_port *port = &atmel_ports[id];
2443 port->backup_imr = 0;
2444 port->uart.line = id;
2446 add_preferred_console(ATMEL_DEVICENAME, id, NULL);
2447 ret = atmel_init_port(port, atmel_default_console_device);
2450 register_console(&atmel_console);
2456 console_initcall(atmel_console_init);
2459 * Late console initialization.
2461 static int __init atmel_late_console_init(void)
2463 if (atmel_default_console_device
2464 && !(atmel_console.flags & CON_ENABLED))
2465 register_console(&atmel_console);
2470 core_initcall(atmel_late_console_init);
2472 static inline bool atmel_is_console_port(struct uart_port *port)
2474 return port->cons && port->cons->index == port->line;
2478 #define ATMEL_CONSOLE_DEVICE NULL
2480 static inline bool atmel_is_console_port(struct uart_port *port)
2486 static struct uart_driver atmel_uart = {
2487 .owner = THIS_MODULE,
2488 .driver_name = "atmel_serial",
2489 .dev_name = ATMEL_DEVICENAME,
2490 .major = SERIAL_ATMEL_MAJOR,
2491 .minor = MINOR_START,
2492 .nr = ATMEL_MAX_UART,
2493 .cons = ATMEL_CONSOLE_DEVICE,
2497 static bool atmel_serial_clk_will_stop(void)
2499 #ifdef CONFIG_ARCH_AT91
2500 return at91_suspend_entering_slow_clock();
2506 static int atmel_serial_suspend(struct platform_device *pdev,
2509 struct uart_port *port = platform_get_drvdata(pdev);
2510 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
2512 if (atmel_is_console_port(port) && console_suspend_enabled) {
2513 /* Drain the TX shifter */
2514 while (!(UART_GET_CSR(port) & ATMEL_US_TXEMPTY))
2518 /* we can not wake up if we're running on slow clock */
2519 atmel_port->may_wakeup = device_may_wakeup(&pdev->dev);
2520 if (atmel_serial_clk_will_stop())
2521 device_set_wakeup_enable(&pdev->dev, 0);
2523 uart_suspend_port(&atmel_uart, port);
2528 static int atmel_serial_resume(struct platform_device *pdev)
2530 struct uart_port *port = platform_get_drvdata(pdev);
2531 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
2533 uart_resume_port(&atmel_uart, port);
2534 device_set_wakeup_enable(&pdev->dev, atmel_port->may_wakeup);
2539 #define atmel_serial_suspend NULL
2540 #define atmel_serial_resume NULL
2543 static int atmel_init_gpios(struct atmel_uart_port *p, struct device *dev)
2545 enum mctrl_gpio_idx i;
2546 struct gpio_desc *gpiod;
2548 p->gpios = mctrl_gpio_init(dev, 0);
2549 if (IS_ERR(p->gpios))
2550 return PTR_ERR(p->gpios);
2552 for (i = 0; i < UART_GPIO_MAX; i++) {
2553 gpiod = mctrl_gpio_to_gpiod(p->gpios, i);
2554 if (gpiod && (gpiod_get_direction(gpiod) == GPIOF_DIR_IN))
2555 p->gpio_irq[i] = gpiod_to_irq(gpiod);
2557 p->gpio_irq[i] = -EINVAL;
2563 static int atmel_serial_probe(struct platform_device *pdev)
2565 struct atmel_uart_port *port;
2566 struct device_node *np = pdev->dev.of_node;
2567 struct atmel_uart_data *pdata = dev_get_platdata(&pdev->dev);
2572 BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
2575 ret = of_alias_get_id(np, "serial");
2581 /* port id not found in platform data nor device-tree aliases:
2582 * auto-enumerate it */
2583 ret = find_first_zero_bit(atmel_ports_in_use, ATMEL_MAX_UART);
2585 if (ret >= ATMEL_MAX_UART) {
2590 if (test_and_set_bit(ret, atmel_ports_in_use)) {
2591 /* port already in use */
2596 port = &atmel_ports[ret];
2597 port->backup_imr = 0;
2598 port->uart.line = ret;
2600 ret = atmel_init_gpios(port, &pdev->dev);
2602 dev_err(&pdev->dev, "Failed to initialize GPIOs.");
2606 ret = atmel_init_port(port, pdev);
2610 if (!atmel_use_pdc_rx(&port->uart)) {
2612 data = kmalloc(sizeof(struct atmel_uart_char)
2613 * ATMEL_SERIAL_RINGSIZE, GFP_KERNEL);
2615 goto err_alloc_ring;
2616 port->rx_ring.buf = data;
2619 rs485_enabled = port->uart.rs485.flags & SER_RS485_ENABLED;
2621 ret = uart_add_one_port(&atmel_uart, &port->uart);
2625 #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
2626 if (atmel_is_console_port(&port->uart)
2627 && ATMEL_CONSOLE_DEVICE->flags & CON_ENABLED) {
2629 * The serial core enabled the clock for us, so undo
2630 * the clk_prepare_enable() in atmel_console_setup()
2632 clk_disable_unprepare(port->clk);
2636 device_init_wakeup(&pdev->dev, 1);
2637 platform_set_drvdata(pdev, port);
2640 * The peripheral clock has been disabled by atmel_init_port():
2641 * enable it before accessing I/O registers
2643 clk_prepare_enable(port->clk);
2645 if (rs485_enabled) {
2646 UART_PUT_MR(&port->uart, ATMEL_US_USMODE_NORMAL);
2647 UART_PUT_CR(&port->uart, ATMEL_US_RTSEN);
2651 * Get port name of usart or uart
2653 atmel_get_ip_name(&port->uart);
2656 * The peripheral clock can now safely be disabled till the port
2659 clk_disable_unprepare(port->clk);
2664 kfree(port->rx_ring.buf);
2665 port->rx_ring.buf = NULL;
2667 if (!atmel_is_console_port(&port->uart)) {
2672 clear_bit(port->uart.line, atmel_ports_in_use);
2677 static int atmel_serial_remove(struct platform_device *pdev)
2679 struct uart_port *port = platform_get_drvdata(pdev);
2680 struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
2683 tasklet_kill(&atmel_port->tasklet);
2685 device_init_wakeup(&pdev->dev, 0);
2687 ret = uart_remove_one_port(&atmel_uart, port);
2689 kfree(atmel_port->rx_ring.buf);
2691 /* "port" is allocated statically, so we shouldn't free it */
2693 clear_bit(port->line, atmel_ports_in_use);
2695 clk_put(atmel_port->clk);
2700 static struct platform_driver atmel_serial_driver = {
2701 .probe = atmel_serial_probe,
2702 .remove = atmel_serial_remove,
2703 .suspend = atmel_serial_suspend,
2704 .resume = atmel_serial_resume,
2706 .name = "atmel_usart",
2707 .of_match_table = of_match_ptr(atmel_serial_dt_ids),
2711 static int __init atmel_serial_init(void)
2715 ret = uart_register_driver(&atmel_uart);
2719 ret = platform_driver_register(&atmel_serial_driver);
2721 uart_unregister_driver(&atmel_uart);
2726 static void __exit atmel_serial_exit(void)
2728 platform_driver_unregister(&atmel_serial_driver);
2729 uart_unregister_driver(&atmel_uart);
2732 module_init(atmel_serial_init);
2733 module_exit(atmel_serial_exit);
2735 MODULE_AUTHOR("Rick Bronson");
2736 MODULE_DESCRIPTION("Atmel AT91 / AT32 serial port driver");
2737 MODULE_LICENSE("GPL");
2738 MODULE_ALIAS("platform:atmel_usart");