1 // SPDX-License-Identifier: GPL-2.0+
3  * Cadence UART driver (found in Xilinx Zynq)
5  * Copyright (c) 2011 - 2014 Xilinx, Inc.
7  * This driver has originally been pushed by Xilinx using a Zynq-branding. This
42 MODULE_PARM_DESC(rx_trigger_level, "Rx trigger level, 1-63 bytes");
47 MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255");
90 #define CDNS_UART_MR_CLKSEL		0x00000001  /* Pre-scalar selection */
96 #define CDNS_UART_MR_STOPMODE_1_BIT	0x00000000  /* 1 stop bit */
114  * Writing a 1 to IER Enables an interrupt, writing a 1 to IDR disables an
151 #define CDNS_UART_RXBS_SUPPORT BIT(1)
190  * struct cdns_uart - device data
225 	.delay_rts_before_send = 1,
226 	.delay_rts_after_send = 1,
233  * cdns_uart_handle_rx - Handle the received bytes along with Rx errors.
241 	struct cdns_uart *cdns_uart = port->private_data;  in cdns_uart_handle_rx()
249 	is_rxbs_support = cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT;  in cdns_uart_handle_rx()
251 	while ((readl(port->membase + CDNS_UART_SR) &  in cdns_uart_handle_rx()
254 			rxbs_status = readl(port->membase + CDNS_UART_RXBS);  in cdns_uart_handle_rx()
255 		data = readl(port->membase + CDNS_UART_FIFO);  in cdns_uart_handle_rx()
256 		port->icount.rx++;  in cdns_uart_handle_rx()
258 		 * There is no hardware break detection in Zynq, so we interpret  in cdns_uart_handle_rx()
259 		 * framing error with all-zeros data as a break sequence.  in cdns_uart_handle_rx()
260 		 * Most of the time, there's another non-zero byte at the  in cdns_uart_handle_rx()
265 				port->read_status_mask |= CDNS_UART_IXR_BRK;  in cdns_uart_handle_rx()
266 				framerrprocessed = 1;  in cdns_uart_handle_rx()
271 			port->icount.brk++;  in cdns_uart_handle_rx()
277 		isrstatus &= port->read_status_mask;  in cdns_uart_handle_rx()
278 		isrstatus &= ~port->ignore_status_mask;  in cdns_uart_handle_rx()
279 		status_mask = port->read_status_mask;  in cdns_uart_handle_rx()
280 		status_mask &= ~port->ignore_status_mask;  in cdns_uart_handle_rx()
283 		    (port->read_status_mask & CDNS_UART_IXR_BRK)) {  in cdns_uart_handle_rx()
284 			port->read_status_mask &= ~CDNS_UART_IXR_BRK;  in cdns_uart_handle_rx()
285 			port->icount.brk++;  in cdns_uart_handle_rx()
296 				port->icount.parity++;  in cdns_uart_handle_rx()
301 				port->icount.frame++;  in cdns_uart_handle_rx()
306 				port->icount.parity++;  in cdns_uart_handle_rx()
311 				port->icount.frame++;  in cdns_uart_handle_rx()
316 			port->icount.overrun++;  in cdns_uart_handle_rx()
317 			tty_insert_flip_char(&port->state->port, 0,  in cdns_uart_handle_rx()
320 		tty_insert_flip_char(&port->state->port, data, status);  in cdns_uart_handle_rx()
324 	tty_flip_buffer_push(&port->state->port);  in cdns_uart_handle_rx()
328  * cdns_rts_gpio_enable - Configure RTS/GPIO to high/low
336 	if (cdns_uart->gpiod_rts) {  in cdns_rts_gpio_enable()
337 		gpiod_set_value(cdns_uart->gpiod_rts, enable);  in cdns_rts_gpio_enable()
339 		val = readl(cdns_uart->port->membase + CDNS_UART_MODEMCR);  in cdns_rts_gpio_enable()
344 		writel(val, cdns_uart->port->membase + CDNS_UART_MODEMCR);  in cdns_rts_gpio_enable()
349  * cdns_rs485_tx_setup - Tx setup specific to rs485
356 	enable = cdns_uart->port->rs485.flags & SER_RS485_RTS_ON_SEND;  in cdns_rs485_tx_setup()
359 	cdns_uart->rs485_tx_started = true;  in cdns_rs485_tx_setup()
363  * cdns_rs485_rx_setup - Rx setup specific to rs485
370 	enable = cdns_uart->port->rs485.flags & SER_RS485_RTS_AFTER_SEND;  in cdns_rs485_rx_setup()
373 	cdns_uart->rs485_tx_started = false;  in cdns_rs485_rx_setup()
377  * cdns_uart_tx_empty -  Check whether TX is empty
386 	status = readl(port->membase + CDNS_UART_SR);  in cdns_uart_tx_empty()
392  * cdns_rs485_rx_callback - Timer rx callback handler for rs485.
409  * cdns_calc_after_tx_delay - calculate delay required for after tx.
417 	return cdns_uart->port->frame_time  in cdns_calc_after_tx_delay()
418 	       + DIV_ROUND_UP(cdns_uart->port->frame_time, 7)  in cdns_calc_after_tx_delay()
419 	       + (u64)cdns_uart->port->rs485.delay_rts_after_send * NSEC_PER_MSEC;  in cdns_calc_after_tx_delay()
423  * cdns_uart_handle_tx - Handle the bytes to be transmitted.
430 	struct cdns_uart *cdns_uart = port->private_data;  in cdns_uart_handle_tx()
431 	struct tty_port *tport = &port->state->port;  in cdns_uart_handle_tx()
435 	if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port)) {  in cdns_uart_handle_tx()
437 		writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IDR);  in cdns_uart_handle_tx()
441 	numbytes = port->fifosize;  in cdns_uart_handle_tx()
443 	       !(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL) &&  in cdns_uart_handle_tx()
445 		writel(ch, port->membase + CDNS_UART_FIFO);  in cdns_uart_handle_tx()
446 		numbytes--;  in cdns_uart_handle_tx()
449 	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)  in cdns_uart_handle_tx()
453 	writel(CDNS_UART_IXR_TXEMPTY, cdns_uart->port->membase + CDNS_UART_IER);  in cdns_uart_handle_tx()
455 	if (cdns_uart->port->rs485.flags & SER_RS485_ENABLED &&  in cdns_uart_handle_tx()
456 	    (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port))) {  in cdns_uart_handle_tx()
457 		cdns_uart->tx_timer.function = &cdns_rs485_rx_callback;  in cdns_uart_handle_tx()
458 		hrtimer_start(&cdns_uart->tx_timer,  in cdns_uart_handle_tx()
464  * cdns_uart_isr - Interrupt handler
480 	isrstatus = readl(port->membase + CDNS_UART_ISR);  in cdns_uart_isr()
481 	writel(isrstatus, port->membase + CDNS_UART_ISR);  in cdns_uart_isr()
488 	isrstatus &= port->read_status_mask;  in cdns_uart_isr()
489 	isrstatus &= ~port->ignore_status_mask;  in cdns_uart_isr()
495 	    !(readl(port->membase + CDNS_UART_CR) & CDNS_UART_CR_RX_DIS))  in cdns_uart_isr()
503  * cdns_uart_calc_baud_divs - Calculate baud rate divisors
513  *	baud_tx/rx rate = clk/CD * (BDIV + 1)
531 	if (baud < clk / ((CDNS_UART_BDIV_MAX + 1) * CDNS_UART_CD_MAX)) {  in cdns_uart_calc_baud_divs()
532 		*div8 = 1;  in cdns_uart_calc_baud_divs()
539 		cd = DIV_ROUND_CLOSEST(clk, baud * (bdiv + 1));  in cdns_uart_calc_baud_divs()
540 		if (cd < 1 || cd > CDNS_UART_CD_MAX)  in cdns_uart_calc_baud_divs()
543 		calc_baud = clk / (cd * (bdiv + 1));  in cdns_uart_calc_baud_divs()
546 			bauderror = baud - calc_baud;  in cdns_uart_calc_baud_divs()
548 			bauderror = calc_baud - baud;  in cdns_uart_calc_baud_divs()
565  * cdns_uart_set_baud_rate - Calculate and set the baud rate
578 	struct cdns_uart *cdns_uart = port->private_data;  in cdns_uart_set_baud_rate()
580 	calc_baud = cdns_uart_calc_baud_divs(port->uartclk, baud, &bdiv, &cd,  in cdns_uart_set_baud_rate()
584 	mreg = readl(port->membase + CDNS_UART_MR);  in cdns_uart_set_baud_rate()
589 	writel(mreg, port->membase + CDNS_UART_MR);  in cdns_uart_set_baud_rate()
590 	writel(cd, port->membase + CDNS_UART_BAUDGEN);  in cdns_uart_set_baud_rate()
591 	writel(bdiv, port->membase + CDNS_UART_BAUDDIV);  in cdns_uart_set_baud_rate()
592 	cdns_uart->baud = baud;  in cdns_uart_set_baud_rate()
599  * cdns_uart_clk_notifier_cb - Clock notifier callback
615 	port = cdns_uart->port;  in cdns_uart_clk_notifier_cb()
616 	if (port->suspended)  in cdns_uart_clk_notifier_cb()
626 		 * Find out if current baud-rate can be achieved with new clock  in cdns_uart_clk_notifier_cb()
629 		if (!cdns_uart_calc_baud_divs(ndata->new_rate, cdns_uart->baud,  in cdns_uart_clk_notifier_cb()
631 			dev_warn(port->dev, "clock rate change rejected\n");  in cdns_uart_clk_notifier_cb()
635 		uart_port_lock_irqsave(cdns_uart->port, &flags);  in cdns_uart_clk_notifier_cb()
638 		ctrl_reg = readl(port->membase + CDNS_UART_CR);  in cdns_uart_clk_notifier_cb()
640 		writel(ctrl_reg, port->membase + CDNS_UART_CR);  in cdns_uart_clk_notifier_cb()
642 		uart_port_unlock_irqrestore(cdns_uart->port, flags);  in cdns_uart_clk_notifier_cb()
652 		uart_port_lock_irqsave(cdns_uart->port, &flags);  in cdns_uart_clk_notifier_cb()
654 		locked = 1;  in cdns_uart_clk_notifier_cb()
655 		port->uartclk = ndata->new_rate;  in cdns_uart_clk_notifier_cb()
657 		cdns_uart->baud = cdns_uart_set_baud_rate(cdns_uart->port,  in cdns_uart_clk_notifier_cb()
658 				cdns_uart->baud);  in cdns_uart_clk_notifier_cb()
662 			uart_port_lock_irqsave(cdns_uart->port, &flags);  in cdns_uart_clk_notifier_cb()
665 		ctrl_reg = readl(port->membase + CDNS_UART_CR);  in cdns_uart_clk_notifier_cb()
667 		writel(ctrl_reg, port->membase + CDNS_UART_CR);  in cdns_uart_clk_notifier_cb()
669 		while (readl(port->membase + CDNS_UART_CR) &  in cdns_uart_clk_notifier_cb()
678 		writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);  in cdns_uart_clk_notifier_cb()
679 		ctrl_reg = readl(port->membase + CDNS_UART_CR);  in cdns_uart_clk_notifier_cb()
682 		writel(ctrl_reg, port->membase + CDNS_UART_CR);  in cdns_uart_clk_notifier_cb()
684 		uart_port_unlock_irqrestore(cdns_uart->port, flags);  in cdns_uart_clk_notifier_cb()
694  * cdns_rs485_tx_callback - Timer tx callback handler for rs485.
701 	uart_port_lock(cdns_uart->port);  in cdns_rs485_tx_callback()
702 	cdns_uart_handle_tx(cdns_uart->port);  in cdns_rs485_tx_callback()
703 	uart_port_unlock(cdns_uart->port);  in cdns_rs485_tx_callback()
709  * cdns_uart_start_tx -  Start transmitting bytes
715 	struct cdns_uart *cdns_uart = port->private_data;  in cdns_uart_start_tx()
724 	status = readl(port->membase + CDNS_UART_CR);  in cdns_uart_start_tx()
727 	writel(status, port->membase + CDNS_UART_CR);  in cdns_uart_start_tx()
729 	if (kfifo_is_empty(&port->state->port.xmit_fifo))  in cdns_uart_start_tx()
733 	writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_ISR);  in cdns_uart_start_tx()
735 	if (cdns_uart->port->rs485.flags & SER_RS485_ENABLED) {  in cdns_uart_start_tx()
736 		if (!cdns_uart->rs485_tx_started) {  in cdns_uart_start_tx()
737 			cdns_uart->tx_timer.function = &cdns_rs485_tx_callback;  in cdns_uart_start_tx()
739 			return hrtimer_start(&cdns_uart->tx_timer,  in cdns_uart_start_tx()
740 					     ms_to_ktime(port->rs485.delay_rts_before_send),  in cdns_uart_start_tx()
748  * cdns_uart_stop_tx - Stop TX
754 	struct cdns_uart *cdns_uart = port->private_data;  in cdns_uart_stop_tx()
756 	if (cdns_uart->port->rs485.flags & SER_RS485_ENABLED)  in cdns_uart_stop_tx()
759 	regval = readl(port->membase + CDNS_UART_CR);  in cdns_uart_stop_tx()
762 	writel(regval, port->membase + CDNS_UART_CR);  in cdns_uart_stop_tx()
766  * cdns_uart_stop_rx - Stop RX
774 	writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IDR);  in cdns_uart_stop_rx()
777 	regval = readl(port->membase + CDNS_UART_CR);  in cdns_uart_stop_rx()
779 	writel(regval, port->membase + CDNS_UART_CR);  in cdns_uart_stop_rx()
783  * cdns_uart_break_ctl - Based on the input ctl we have to start or stop
795 	status = readl(port->membase + CDNS_UART_CR);  in cdns_uart_break_ctl()
797 	if (ctl == -1)  in cdns_uart_break_ctl()
799 				port->membase + CDNS_UART_CR);  in cdns_uart_break_ctl()
803 					port->membase + CDNS_UART_CR);  in cdns_uart_break_ctl()
809  * cdns_uart_set_termios - termios operations, handling data length, parity,
827 	ctrl_reg = readl(port->membase + CDNS_UART_CR);  in cdns_uart_set_termios()
829 	writel(ctrl_reg, port->membase + CDNS_UART_CR);  in cdns_uart_set_termios()
833 	 * min and max baud should be calculated here based on port->uartclk.  in cdns_uart_set_termios()
834 	 * this way we get a valid baud and can safely call set_baud()  in cdns_uart_set_termios()
836 	minbaud = port->uartclk /  in cdns_uart_set_termios()
837 			((CDNS_UART_BDIV_MAX + 1) * CDNS_UART_CD_MAX * 8);  in cdns_uart_set_termios()
838 	maxbaud = port->uartclk / (CDNS_UART_BDIV_MIN + 1);  in cdns_uart_set_termios()
844 	/* Update the per-port timeout. */  in cdns_uart_set_termios()
845 	uart_update_timeout(port, termios->c_cflag, baud);  in cdns_uart_set_termios()
848 	ctrl_reg = readl(port->membase + CDNS_UART_CR);  in cdns_uart_set_termios()
850 	writel(ctrl_reg, port->membase + CDNS_UART_CR);  in cdns_uart_set_termios()
852 	while (readl(port->membase + CDNS_UART_CR) &  in cdns_uart_set_termios()
860 	ctrl_reg = readl(port->membase + CDNS_UART_CR);  in cdns_uart_set_termios()
863 	writel(ctrl_reg, port->membase + CDNS_UART_CR);  in cdns_uart_set_termios()
865 	writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);  in cdns_uart_set_termios()
867 	port->read_status_mask = CDNS_UART_IXR_TXEMPTY | CDNS_UART_IXR_RXTRIG |  in cdns_uart_set_termios()
869 	port->ignore_status_mask = 0;  in cdns_uart_set_termios()
871 	if (termios->c_iflag & INPCK)  in cdns_uart_set_termios()
872 		port->read_status_mask |= CDNS_UART_IXR_PARITY |  in cdns_uart_set_termios()
875 	if (termios->c_iflag & IGNPAR)  in cdns_uart_set_termios()
876 		port->ignore_status_mask |= CDNS_UART_IXR_PARITY |  in cdns_uart_set_termios()
880 	if ((termios->c_cflag & CREAD) == 0)  in cdns_uart_set_termios()
881 		port->ignore_status_mask |= CDNS_UART_IXR_RXTRIG |  in cdns_uart_set_termios()
885 	mode_reg = readl(port->membase + CDNS_UART_MR);  in cdns_uart_set_termios()
888 	switch (termios->c_cflag & CSIZE) {  in cdns_uart_set_termios()
898 		termios->c_cflag &= ~CSIZE;  in cdns_uart_set_termios()
899 		termios->c_cflag |= CS8;  in cdns_uart_set_termios()
904 	if (termios->c_cflag & CSTOPB)  in cdns_uart_set_termios()
907 		cval |= CDNS_UART_MR_STOPMODE_1_BIT; /* 1 STOP bit */  in cdns_uart_set_termios()
909 	if (termios->c_cflag & PARENB) {  in cdns_uart_set_termios()
911 		if (termios->c_cflag & CMSPAR) {  in cdns_uart_set_termios()
912 			if (termios->c_cflag & PARODD)  in cdns_uart_set_termios()
917 			if (termios->c_cflag & PARODD)  in cdns_uart_set_termios()
925 	cval |= mode_reg & 1;  in cdns_uart_set_termios()
926 	writel(cval, port->membase + CDNS_UART_MR);  in cdns_uart_set_termios()
928 	cval = readl(port->membase + CDNS_UART_MODEMCR);  in cdns_uart_set_termios()
929 	if (termios->c_cflag & CRTSCTS)  in cdns_uart_set_termios()
933 	writel(cval, port->membase + CDNS_UART_MODEMCR);  in cdns_uart_set_termios()
939  * cdns_uart_startup - Called when an application opens a cdns_uart port
946 	struct cdns_uart *cdns_uart = port->private_data;  in cdns_uart_startup()
952 	is_brk_support = cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT;  in cdns_uart_startup()
954 	ret = reset_control_deassert(cdns_uart->rstc);  in cdns_uart_startup()
962 			port->membase + CDNS_UART_CR);  in cdns_uart_startup()
968 			port->membase + CDNS_UART_CR);  in cdns_uart_startup()
970 	while (readl(port->membase + CDNS_UART_CR) &  in cdns_uart_startup()
974 	if (cdns_uart->port->rs485.flags & SER_RS485_ENABLED)  in cdns_uart_startup()
981 	status = readl(port->membase + CDNS_UART_CR);  in cdns_uart_startup()
984 	writel(status, port->membase + CDNS_UART_CR);  in cdns_uart_startup()
986 	/* Set the Mode Register with normal mode,8 data bits,1 stop bit,  in cdns_uart_startup()
991 		port->membase + CDNS_UART_MR);  in cdns_uart_startup()
995 	 * can be tuned with a module parameter  in cdns_uart_startup()
997 	writel(rx_trigger_level, port->membase + CDNS_UART_RXWM);  in cdns_uart_startup()
1001 	 * can be tuned with a module parameter  in cdns_uart_startup()
1003 	writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);  in cdns_uart_startup()
1006 	writel(readl(port->membase + CDNS_UART_ISR),  in cdns_uart_startup()
1007 			port->membase + CDNS_UART_ISR);  in cdns_uart_startup()
1011 	ret = request_irq(port->irq, cdns_uart_isr, 0, CDNS_UART_NAME, port);  in cdns_uart_startup()
1013 		dev_err(port->dev, "request_irq '%d' failed with %d\n",  in cdns_uart_startup()
1014 			port->irq, ret);  in cdns_uart_startup()
1021 					port->membase + CDNS_UART_IER);  in cdns_uart_startup()
1023 		writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IER);  in cdns_uart_startup()
1029  * cdns_uart_shutdown - Called when an application closes a cdns_uart port
1036 	struct cdns_uart *cdns_uart = port->private_data;  in cdns_uart_shutdown()
1038 	if (cdns_uart->port->rs485.flags & SER_RS485_ENABLED)  in cdns_uart_shutdown()
1039 		hrtimer_cancel(&cdns_uart->tx_timer);  in cdns_uart_shutdown()
1044 	status = readl(port->membase + CDNS_UART_IMR);  in cdns_uart_shutdown()
1045 	writel(status, port->membase + CDNS_UART_IDR);  in cdns_uart_shutdown()
1046 	writel(0xffffffff, port->membase + CDNS_UART_ISR);  in cdns_uart_shutdown()
1050 			port->membase + CDNS_UART_CR);  in cdns_uart_shutdown()
1054 	free_irq(port->irq, port);  in cdns_uart_shutdown()
1058  * cdns_uart_type - Set UART type to cdns_uart port
1065 	return port->type == PORT_XUARTPS ? CDNS_UART_NAME : NULL;  in cdns_uart_type()
1069  * cdns_uart_verify_port - Verify the port params
1078 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_XUARTPS)  in cdns_uart_verify_port()
1079 		return -EINVAL;  in cdns_uart_verify_port()
1080 	if (port->irq != ser->irq)  in cdns_uart_verify_port()
1081 		return -EINVAL;  in cdns_uart_verify_port()
1082 	if (ser->io_type != UPIO_MEM)  in cdns_uart_verify_port()
1083 		return -EINVAL;  in cdns_uart_verify_port()
1084 	if (port->iobase != ser->port)  in cdns_uart_verify_port()
1085 		return -EINVAL;  in cdns_uart_verify_port()
1086 	if (ser->hub6 != 0)  in cdns_uart_verify_port()
1087 		return -EINVAL;  in cdns_uart_verify_port()
1092  * cdns_uart_request_port - Claim the memory region attached to cdns_uart port,
1101 	if (!request_mem_region(port->mapbase, CDNS_UART_REGISTER_SPACE,  in cdns_uart_request_port()
1103 		return -ENOMEM;  in cdns_uart_request_port()
1106 	port->membase = ioremap(port->mapbase, CDNS_UART_REGISTER_SPACE);  in cdns_uart_request_port()
1107 	if (!port->membase) {  in cdns_uart_request_port()
1108 		dev_err(port->dev, "Unable to map registers\n");  in cdns_uart_request_port()
1109 		release_mem_region(port->mapbase, CDNS_UART_REGISTER_SPACE);  in cdns_uart_request_port()
1110 		return -ENOMEM;  in cdns_uart_request_port()
1116  * cdns_uart_release_port - Release UART port
1124 	release_mem_region(port->mapbase, CDNS_UART_REGISTER_SPACE);  in cdns_uart_release_port()
1125 	iounmap(port->membase);  in cdns_uart_release_port()
1126 	port->membase = NULL;  in cdns_uart_release_port()
1130  * cdns_uart_config_port - Configure UART port
1137 		port->type = PORT_XUARTPS;  in cdns_uart_config_port()
1141  * cdns_uart_get_mctrl - Get the modem control state
1150 	struct cdns_uart *cdns_uart_data = port->private_data;  in cdns_uart_get_mctrl()
1152 	if (cdns_uart_data->cts_override)  in cdns_uart_get_mctrl()
1155 	val = readl(port->membase + CDNS_UART_MODEMSR);  in cdns_uart_get_mctrl()
1172 	struct cdns_uart *cdns_uart_data = port->private_data;  in cdns_uart_set_mctrl()
1174 	if (cdns_uart_data->cts_override)  in cdns_uart_set_mctrl()
1177 	val = readl(port->membase + CDNS_UART_MODEMCR);  in cdns_uart_set_mctrl()
1178 	mode_reg = readl(port->membase + CDNS_UART_MR);  in cdns_uart_set_mctrl()
1185 	if (cdns_uart_data->gpiod_rts)  in cdns_uart_set_mctrl()
1186 		gpiod_set_value(cdns_uart_data->gpiod_rts, !(mctrl & TIOCM_RTS));  in cdns_uart_set_mctrl()
1194 	writel(val, port->membase + CDNS_UART_MODEMCR);  in cdns_uart_set_mctrl()
1195 	writel(mode_reg, port->membase + CDNS_UART_MR);  in cdns_uart_set_mctrl()
1207 	if (readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_RXEMPTY)  in cdns_uart_poll_get_char()
1210 		c = (unsigned char) readl(port->membase + CDNS_UART_FIFO);  in cdns_uart_poll_get_char()
1224 	while (!(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXEMPTY))  in cdns_uart_poll_put_char()
1228 	writel(c, port->membase + CDNS_UART_FIFO);  in cdns_uart_poll_put_char()
1231 	while (!(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXEMPTY))  in cdns_uart_poll_put_char()
1243 		pm_runtime_mark_last_busy(port->dev);  in cdns_uart_pm()
1244 		pm_runtime_put_autosuspend(port->dev);  in cdns_uart_pm()
1247 		pm_runtime_get_sync(port->dev);  in cdns_uart_pm()
1279  * cdns_uart_console_putchar - write the character to the FIFO buffer
1289 	while (1) {  in cdns_uart_console_putchar()
1290 		ctrl_reg = readl(port->membase + CDNS_UART_CR);  in cdns_uart_console_putchar()
1294 			dev_warn(port->dev,  in cdns_uart_console_putchar()
1302 	while (1) {  in cdns_uart_console_putchar()
1303 		ctrl_reg = readl(port->membase + CDNS_UART_SR);  in cdns_uart_console_putchar()
1308 			dev_warn(port->dev,  in cdns_uart_console_putchar()
1314 	writel(ch, port->membase + CDNS_UART_FIFO);  in cdns_uart_console_putchar()
1320 	struct earlycon_device *dev = con->data;  in cdns_early_write()
1322 	uart_console_write(&dev->port, s, n, cdns_uart_console_putchar);  in cdns_early_write()
1328 	struct uart_port *port = &device->port;  in cdns_early_console_setup()
1330 	if (!port->membase)  in cdns_early_console_setup()
1331 		return -ENODEV;  in cdns_early_console_setup()
1335 	       port->membase + CDNS_UART_CR);  in cdns_early_console_setup()
1337 	/* only set baud if specified on command line - otherwise  in cdns_early_console_setup()
1340 	if (port->uartclk && device->baud) {  in cdns_early_console_setup()
1345 		cdns_uart_calc_baud_divs(port->uartclk, device->baud,  in cdns_early_console_setup()
1351 		writel(mr,   port->membase + CDNS_UART_MR);  in cdns_early_console_setup()
1352 		writel(cd,   port->membase + CDNS_UART_BAUDGEN);  in cdns_early_console_setup()
1353 		writel(bdiv, port->membase + CDNS_UART_BAUDDIV);  in cdns_early_console_setup()
1356 	device->con->write = cdns_early_write;  in cdns_early_console_setup()
1361 OF_EARLYCON_DECLARE(cdns, "cdns,uart-r1p8", cdns_early_console_setup);
1362 OF_EARLYCON_DECLARE(cdns, "cdns,uart-r1p12", cdns_early_console_setup);
1363 OF_EARLYCON_DECLARE(cdns, "xlnx,zynqmp-uart", cdns_early_console_setup);
1370  * cdns_uart_console_write - perform write operation
1381 	int locked = 1;  in cdns_uart_console_write()
1383 	if (port->sysrq)  in cdns_uart_console_write()
1391 	imr = readl(port->membase + CDNS_UART_IMR);  in cdns_uart_console_write()
1392 	writel(imr, port->membase + CDNS_UART_IDR);  in cdns_uart_console_write()
1398 	ctrl = readl(port->membase + CDNS_UART_CR);  in cdns_uart_console_write()
1401 	writel(ctrl, port->membase + CDNS_UART_CR);  in cdns_uart_console_write()
1408 	writel(imr, port->membase + CDNS_UART_IER);  in cdns_uart_console_write()
1415  * cdns_uart_console_setup - Initialize the uart to default config
1431 	if (!port->membase) {  in cdns_uart_console_setup()
1433 			 co->index);  in cdns_uart_console_setup()
1434 		return -ENODEV;  in cdns_uart_console_setup()
1456 	.index	= -1, /* Specified on the cmdline (e.g. console=ttyPS ) */
1463  * cdns_uart_suspend - suspend event
1471 	struct cdns_uart *cdns_uart = port->private_data;  in cdns_uart_suspend()
1480 		/* Empty the receive FIFO 1st before making changes */  in cdns_uart_suspend()
1481 		while (!(readl(port->membase + CDNS_UART_SR) &  in cdns_uart_suspend()
1483 			readl(port->membase + CDNS_UART_FIFO);  in cdns_uart_suspend()
1484 		/* set RX trigger level to 1 */  in cdns_uart_suspend()
1485 		writel(1, port->membase + CDNS_UART_RXWM);  in cdns_uart_suspend()
1487 		writel(CDNS_UART_IXR_TOUT, port->membase + CDNS_UART_IDR);  in cdns_uart_suspend()
1495 	return uart_suspend_port(cdns_uart->cdns_uart_driver, port);  in cdns_uart_suspend()
1499  * cdns_uart_resume - Resume after a previous suspend
1507 	struct cdns_uart *cdns_uart = port->private_data;  in cdns_uart_resume()
1516 		ret = clk_enable(cdns_uart->pclk);  in cdns_uart_resume()
1520 		ret = clk_enable(cdns_uart->uartclk);  in cdns_uart_resume()
1522 			clk_disable(cdns_uart->pclk);  in cdns_uart_resume()
1529 		ctrl_reg = readl(port->membase + CDNS_UART_CR);  in cdns_uart_resume()
1531 		writel(ctrl_reg, port->membase + CDNS_UART_CR);  in cdns_uart_resume()
1532 		while (readl(port->membase + CDNS_UART_CR) &  in cdns_uart_resume()
1537 		writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);  in cdns_uart_resume()
1539 		ctrl_reg = readl(port->membase + CDNS_UART_CR);  in cdns_uart_resume()
1542 		writel(ctrl_reg, port->membase + CDNS_UART_CR);  in cdns_uart_resume()
1544 		clk_disable(cdns_uart->uartclk);  in cdns_uart_resume()
1545 		clk_disable(cdns_uart->pclk);  in cdns_uart_resume()
1550 		writel(rx_trigger_level, port->membase + CDNS_UART_RXWM);  in cdns_uart_resume()
1552 		writel(CDNS_UART_IXR_TOUT, port->membase + CDNS_UART_IER);  in cdns_uart_resume()
1556 	return uart_resume_port(cdns_uart->cdns_uart_driver, port);  in cdns_uart_resume()
1562 	struct cdns_uart *cdns_uart = port->private_data;  in cdns_runtime_suspend()
1564 	clk_disable(cdns_uart->uartclk);  in cdns_runtime_suspend()
1565 	clk_disable(cdns_uart->pclk);  in cdns_runtime_suspend()
1572 	struct cdns_uart *cdns_uart = port->private_data;  in cdns_runtime_resume()
1575 	ret = clk_enable(cdns_uart->pclk);  in cdns_runtime_resume()
1579 	ret = clk_enable(cdns_uart->uartclk);  in cdns_runtime_resume()
1581 		clk_disable(cdns_uart->pclk);  in cdns_runtime_resume()
1599 	{ .compatible = "cdns,uart-r1p8", },
1600 	{ .compatible = "cdns,uart-r1p12", .data = &zynqmp_uart_def },
1601 	{ .compatible = "xlnx,zynqmp-uart", .data = &zynqmp_uart_def },
1610  * cdns_rs485_config - Called when an application calls TIOCSRS485 ioctl.
1621 	struct cdns_uart *cdns_uart = port->private_data;  in cdns_rs485_config()
1623 	if (rs485->flags & SER_RS485_ENABLED) {  in cdns_rs485_config()
1624 		dev_dbg(port->dev, "Setting UART to RS485\n");  in cdns_rs485_config()
1626 		val = readl(port->membase + CDNS_UART_MODEMCR);  in cdns_rs485_config()
1628 		writel(val, port->membase + CDNS_UART_MODEMCR);  in cdns_rs485_config()
1631 		hrtimer_init(&cdns_uart->tx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);  in cdns_rs485_config()
1632 		cdns_uart->tx_timer.function = &cdns_rs485_tx_callback;  in cdns_rs485_config()
1637 		hrtimer_cancel(&cdns_uart->tx_timer);  in cdns_rs485_config()
1643  * cdns_uart_probe - Platform driver probe
1656 	cdns_uart_data = devm_kzalloc(&pdev->dev, sizeof(*cdns_uart_data),  in cdns_uart_probe()
1659 		return -ENOMEM;  in cdns_uart_probe()
1660 	port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);  in cdns_uart_probe()
1662 		return -ENOMEM;  in cdns_uart_probe()
1665 	id = of_alias_get_id(pdev->dev.of_node, "serial");  in cdns_uart_probe()
1670 		dev_err(&pdev->dev, "Cannot get uart_port structure\n");  in cdns_uart_probe()
1671 		return -ENODEV;  in cdns_uart_probe()
1687 			dev_err(&pdev->dev, "Failed to register driver\n");  in cdns_uart_probe()
1692 	cdns_uart_data->cdns_uart_driver = &cdns_uart_uart_driver;  in cdns_uart_probe()
1694 	match = of_match_node(cdns_uart_of_match, pdev->dev.of_node);  in cdns_uart_probe()
1695 	if (match && match->data) {  in cdns_uart_probe()
1696 		const struct cdns_platform_data *data = match->data;  in cdns_uart_probe()
1698 		cdns_uart_data->quirks = data->quirks;  in cdns_uart_probe()
1701 	cdns_uart_data->pclk = devm_clk_get(&pdev->dev, "pclk");  in cdns_uart_probe()
1702 	if (PTR_ERR(cdns_uart_data->pclk) == -EPROBE_DEFER) {  in cdns_uart_probe()
1703 		rc = PTR_ERR(cdns_uart_data->pclk);  in cdns_uart_probe()
1707 	if (IS_ERR(cdns_uart_data->pclk)) {  in cdns_uart_probe()
1708 		cdns_uart_data->pclk = devm_clk_get(&pdev->dev, "aper_clk");  in cdns_uart_probe()
1709 		if (IS_ERR(cdns_uart_data->pclk)) {  in cdns_uart_probe()
1710 			rc = PTR_ERR(cdns_uart_data->pclk);  in cdns_uart_probe()
1713 		dev_err(&pdev->dev, "clock name 'aper_clk' is deprecated.\n");  in cdns_uart_probe()
1716 	cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "uart_clk");  in cdns_uart_probe()
1717 	if (PTR_ERR(cdns_uart_data->uartclk) == -EPROBE_DEFER) {  in cdns_uart_probe()
1718 		rc = PTR_ERR(cdns_uart_data->uartclk);  in cdns_uart_probe()
1722 	if (IS_ERR(cdns_uart_data->uartclk)) {  in cdns_uart_probe()
1723 		cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "ref_clk");  in cdns_uart_probe()
1724 		if (IS_ERR(cdns_uart_data->uartclk)) {  in cdns_uart_probe()
1725 			rc = PTR_ERR(cdns_uart_data->uartclk);  in cdns_uart_probe()
1728 		dev_err(&pdev->dev, "clock name 'ref_clk' is deprecated.\n");  in cdns_uart_probe()
1731 	cdns_uart_data->rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);  in cdns_uart_probe()
1732 	if (IS_ERR(cdns_uart_data->rstc)) {  in cdns_uart_probe()
1733 		rc = PTR_ERR(cdns_uart_data->rstc);  in cdns_uart_probe()
1734 		dev_err_probe(&pdev->dev, rc, "Cannot get UART reset\n");  in cdns_uart_probe()
1738 	rc = clk_prepare_enable(cdns_uart_data->pclk);  in cdns_uart_probe()
1740 		dev_err(&pdev->dev, "Unable to enable pclk clock.\n");  in cdns_uart_probe()
1743 	rc = clk_prepare_enable(cdns_uart_data->uartclk);  in cdns_uart_probe()
1745 		dev_err(&pdev->dev, "Unable to enable device clock.\n");  in cdns_uart_probe()
1751 		rc = -ENODEV;  in cdns_uart_probe()
1762 	cdns_uart_data->clk_rate_change_nb.notifier_call =  in cdns_uart_probe()
1764 	if (clk_notifier_register(cdns_uart_data->uartclk,  in cdns_uart_probe()
1765 				&cdns_uart_data->clk_rate_change_nb))  in cdns_uart_probe()
1766 		dev_warn(&pdev->dev, "Unable to register clock notifier.\n");  in cdns_uart_probe()
1770 	spin_lock_init(&port->lock);  in cdns_uart_probe()
1771 	port->type	= PORT_UNKNOWN;  in cdns_uart_probe()
1772 	port->iotype	= UPIO_MEM32;  in cdns_uart_probe()
1773 	port->flags	= UPF_BOOT_AUTOCONF;  in cdns_uart_probe()
1774 	port->ops	= &cdns_uart_ops;  in cdns_uart_probe()
1775 	port->fifosize	= CDNS_UART_FIFO_SIZE;  in cdns_uart_probe()
1776 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_XILINX_PS_UART_CONSOLE);  in cdns_uart_probe()
1777 	port->line	= id;  in cdns_uart_probe()
1784 	port->mapbase = res->start;  in cdns_uart_probe()
1785 	port->irq = irq;  in cdns_uart_probe()
1786 	port->dev = &pdev->dev;  in cdns_uart_probe()
1787 	port->uartclk = clk_get_rate(cdns_uart_data->uartclk);  in cdns_uart_probe()
1788 	port->private_data = cdns_uart_data;  in cdns_uart_probe()
1789 	port->read_status_mask = CDNS_UART_IXR_TXEMPTY | CDNS_UART_IXR_RXTRIG |  in cdns_uart_probe()
1791 	port->rs485_config = cdns_rs485_config;  in cdns_uart_probe()
1792 	port->rs485_supported = cdns_rs485_supported;  in cdns_uart_probe()
1793 	cdns_uart_data->port = port;  in cdns_uart_probe()
1800 	cdns_uart_data->gpiod_rts = devm_gpiod_get_optional(&pdev->dev, "rts",  in cdns_uart_probe()
1802 	if (IS_ERR(cdns_uart_data->gpiod_rts)) {  in cdns_uart_probe()
1803 		rc = PTR_ERR(cdns_uart_data->gpiod_rts);  in cdns_uart_probe()
1804 		dev_err(port->dev, "xuartps: devm_gpiod_get_optional failed\n");  in cdns_uart_probe()
1808 	pm_runtime_use_autosuspend(&pdev->dev);  in cdns_uart_probe()
1809 	pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT);  in cdns_uart_probe()
1810 	pm_runtime_set_active(&pdev->dev);  in cdns_uart_probe()
1811 	pm_runtime_enable(&pdev->dev);  in cdns_uart_probe()
1812 	device_init_wakeup(port->dev, true);  in cdns_uart_probe()
1826 	if (cdns_uart_data->port->rs485.flags & SER_RS485_ENABLED)  in cdns_uart_probe()
1831 		dev_err(&pdev->dev,  in cdns_uart_probe()
1841 		cdns_uart_console.index = -1;  in cdns_uart_probe()
1845 	cdns_uart_data->cts_override = of_property_read_bool(pdev->dev.of_node,  in cdns_uart_probe()
1846 							     "cts-override");  in cdns_uart_probe()
1853 	pm_runtime_disable(&pdev->dev);  in cdns_uart_probe()
1854 	pm_runtime_set_suspended(&pdev->dev);  in cdns_uart_probe()
1855 	pm_runtime_dont_use_autosuspend(&pdev->dev);  in cdns_uart_probe()
1858 	clk_notifier_unregister(cdns_uart_data->uartclk,  in cdns_uart_probe()
1859 			&cdns_uart_data->clk_rate_change_nb);  in cdns_uart_probe()
1862 	clk_disable_unprepare(cdns_uart_data->uartclk);  in cdns_uart_probe()
1864 	clk_disable_unprepare(cdns_uart_data->pclk);  in cdns_uart_probe()
1867 		uart_unregister_driver(cdns_uart_data->cdns_uart_driver);  in cdns_uart_probe()
1872  * cdns_uart_remove - called when the platform driver is unregistered
1878 	struct cdns_uart *cdns_uart_data = port->private_data;  in cdns_uart_remove()
1882 	clk_notifier_unregister(cdns_uart_data->uartclk,  in cdns_uart_remove()
1883 			&cdns_uart_data->clk_rate_change_nb);  in cdns_uart_remove()
1885 	uart_remove_one_port(cdns_uart_data->cdns_uart_driver, port);  in cdns_uart_remove()
1886 	port->mapbase = 0;  in cdns_uart_remove()
1887 	clk_disable_unprepare(cdns_uart_data->uartclk);  in cdns_uart_remove()
1888 	clk_disable_unprepare(cdns_uart_data->pclk);  in cdns_uart_remove()
1889 	pm_runtime_disable(&pdev->dev);  in cdns_uart_remove()
1890 	pm_runtime_set_suspended(&pdev->dev);  in cdns_uart_remove()
1891 	pm_runtime_dont_use_autosuspend(&pdev->dev);  in cdns_uart_remove()
1892 	device_init_wakeup(&pdev->dev, false);  in cdns_uart_remove()
1898 	reset_control_assert(cdns_uart_data->rstc);  in cdns_uart_remove()
1900 	if (!--instances)  in cdns_uart_remove()
1901 		uart_unregister_driver(cdns_uart_data->cdns_uart_driver);  in cdns_uart_remove()