229  * @ssp: pointer to a struct sifive_serial_port record
232  * IP block base, given a pointer @ssp to a struct sifive_serial_port record.
236 static void __ssp_writel(u32 v, u16 offs, struct sifive_serial_port *ssp)  in __ssp_writel()  argument
238 	__ssp_early_writel(v, offs, &ssp->port);  in __ssp_writel()
243  * @ssp: pointer to a struct sifive_serial_port record
247  * IP block base, given a pointer @ssp to a struct sifive_serial_port record.
253 static u32 __ssp_readl(struct sifive_serial_port *ssp, u16 offs)  in __ssp_readl()  argument
255 	return __ssp_early_readl(&ssp->port, offs);  in __ssp_readl()
260  * @ssp: pointer to a struct sifive_serial_port
269 static int sifive_serial_is_txfifo_full(struct sifive_serial_port *ssp)  in sifive_serial_is_txfifo_full()  argument
271 	return __ssp_readl(ssp, SIFIVE_SERIAL_TXDATA_OFFS) &  in sifive_serial_is_txfifo_full()
277  * @ssp: pointer to a struct sifive_serial_port
280  * Enqueue a byte @ch onto the transmit FIFO, given a pointer @ssp to the
286 static void __ssp_transmit_char(struct sifive_serial_port *ssp, int ch)  in __ssp_transmit_char()  argument
288 	__ssp_writel(ch, SIFIVE_SERIAL_TXDATA_OFFS, ssp);  in __ssp_transmit_char()
293  * @ssp: pointer to a struct sifive_serial_port
298  * Context: Any context.  Expects @ssp->port.lock to be held by caller.
300 static void __ssp_transmit_chars(struct sifive_serial_port *ssp)  in __ssp_transmit_chars()  argument
302 	struct circ_buf *xmit = &ssp->port.state->xmit;  in __ssp_transmit_chars()
305 	if (ssp->port.x_char) {  in __ssp_transmit_chars()
306 		__ssp_transmit_char(ssp, ssp->port.x_char);  in __ssp_transmit_chars()
307 		ssp->port.icount.tx++;  in __ssp_transmit_chars()
308 		ssp->port.x_char = 0;  in __ssp_transmit_chars()
311 	if (uart_circ_empty(xmit) || uart_tx_stopped(&ssp->port)) {  in __ssp_transmit_chars()
312 		sifive_serial_stop_tx(&ssp->port);  in __ssp_transmit_chars()
317 		__ssp_transmit_char(ssp, xmit->buf[xmit->tail]);  in __ssp_transmit_chars()
319 		ssp->port.icount.tx++;  in __ssp_transmit_chars()
325 		uart_write_wakeup(&ssp->port);  in __ssp_transmit_chars()
328 		sifive_serial_stop_tx(&ssp->port);  in __ssp_transmit_chars()
333  * @ssp: pointer to a struct sifive_serial_port
336  * on the SiFive UART referred to by @ssp.
338 static void __ssp_enable_txwm(struct sifive_serial_port *ssp)  in __ssp_enable_txwm()  argument
340 	if (ssp->ier & SIFIVE_SERIAL_IE_TXWM_MASK)  in __ssp_enable_txwm()
343 	ssp->ier |= SIFIVE_SERIAL_IE_TXWM_MASK;  in __ssp_enable_txwm()
344 	__ssp_writel(ssp->ier, SIFIVE_SERIAL_IE_OFFS, ssp);  in __ssp_enable_txwm()
349  * @ssp: pointer to a struct sifive_serial_port
352  * on the SiFive UART referred to by @ssp.
354 static void __ssp_enable_rxwm(struct sifive_serial_port *ssp)  in __ssp_enable_rxwm()  argument
356 	if (ssp->ier & SIFIVE_SERIAL_IE_RXWM_MASK)  in __ssp_enable_rxwm()
359 	ssp->ier |= SIFIVE_SERIAL_IE_RXWM_MASK;  in __ssp_enable_rxwm()
360 	__ssp_writel(ssp->ier, SIFIVE_SERIAL_IE_OFFS, ssp);  in __ssp_enable_rxwm()
365  * @ssp: pointer to a struct sifive_serial_port
368  * on the UART referred to by @ssp.
370 static void __ssp_disable_txwm(struct sifive_serial_port *ssp)  in __ssp_disable_txwm()  argument
372 	if (!(ssp->ier & SIFIVE_SERIAL_IE_TXWM_MASK))  in __ssp_disable_txwm()
375 	ssp->ier &= ~SIFIVE_SERIAL_IE_TXWM_MASK;  in __ssp_disable_txwm()
376 	__ssp_writel(ssp->ier, SIFIVE_SERIAL_IE_OFFS, ssp);  in __ssp_disable_txwm()
381  * @ssp: pointer to a struct sifive_serial_port
384  * on the UART referred to by @ssp.
386 static void __ssp_disable_rxwm(struct sifive_serial_port *ssp)  in __ssp_disable_rxwm()  argument
388 	if (!(ssp->ier & SIFIVE_SERIAL_IE_RXWM_MASK))  in __ssp_disable_rxwm()
391 	ssp->ier &= ~SIFIVE_SERIAL_IE_RXWM_MASK;  in __ssp_disable_rxwm()
392 	__ssp_writel(ssp->ier, SIFIVE_SERIAL_IE_OFFS, ssp);  in __ssp_disable_rxwm()
397  * @ssp: pointer to a struct sifive_serial_port
401  * @ssp, and to return it.  Also returns the RX FIFO empty bit in
407 static char __ssp_receive_char(struct sifive_serial_port *ssp, char *is_empty)  in __ssp_receive_char()  argument
412 	v = __ssp_readl(ssp, SIFIVE_SERIAL_RXDATA_OFFS);  in __ssp_receive_char()
428  * @ssp: pointer to a struct sifive_serial_port
431  * to by @ssp and pass them up to the Linux serial layer.
433  * Context: Expects ssp->port.lock to be held by caller.
435 static void __ssp_receive_chars(struct sifive_serial_port *ssp)  in __ssp_receive_chars()  argument
442 		ch = __ssp_receive_char(ssp, &is_empty);  in __ssp_receive_chars()
446 		ssp->port.icount.rx++;  in __ssp_receive_chars()
447 		uart_insert_char(&ssp->port, 0, 0, ch, TTY_NORMAL);  in __ssp_receive_chars()
450 	spin_unlock(&ssp->port.lock);  in __ssp_receive_chars()
451 	tty_flip_buffer_push(&ssp->port.state->port);  in __ssp_receive_chars()
452 	spin_lock(&ssp->port.lock);  in __ssp_receive_chars()
457  * @ssp: pointer to a struct sifive_serial_port
460  * and target line rate referred to by @ssp and write it into the
463 static void __ssp_update_div(struct sifive_serial_port *ssp)  in __ssp_update_div()  argument
467 	div = DIV_ROUND_UP(ssp->clkin_rate, ssp->baud_rate) - 1;  in __ssp_update_div()
469 	__ssp_writel(div, SIFIVE_SERIAL_DIV_OFFS, ssp);  in __ssp_update_div()
474  * @ssp: pointer to a struct sifive_serial_port
478  * SiFive UART described by @ssp and program it into the UART.  There may
482 static void __ssp_update_baud_rate(struct sifive_serial_port *ssp,  in __ssp_update_baud_rate()  argument
485 	if (ssp->baud_rate == rate)  in __ssp_update_baud_rate()
488 	ssp->baud_rate = rate;  in __ssp_update_baud_rate()
489 	__ssp_update_div(ssp);  in __ssp_update_baud_rate()
494  * @ssp: pointer to a struct sifive_serial_port
497  * Program the SiFive UART referred to by @ssp to use @nstop stop bits.
499 static void __ssp_set_stop_bits(struct sifive_serial_port *ssp, char nstop)  in __ssp_set_stop_bits()  argument
508 	v = __ssp_readl(ssp, SIFIVE_SERIAL_TXCTRL_OFFS);  in __ssp_set_stop_bits()
511 	__ssp_writel(v, SIFIVE_SERIAL_TXCTRL_OFFS, ssp);  in __ssp_set_stop_bits()
516  * @ssp: pointer to a struct sifive_serial_port
518  * Delay while the UART TX FIFO referred to by @ssp is marked as full.
522 static void __maybe_unused __ssp_wait_for_xmitr(struct sifive_serial_port *ssp)  in __ssp_wait_for_xmitr()  argument
524 	while (sifive_serial_is_txfifo_full(ssp))  in __ssp_wait_for_xmitr()
534 	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);  in sifive_serial_stop_tx()  local
536 	__ssp_disable_txwm(ssp);  in sifive_serial_stop_tx()
541 	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);  in sifive_serial_stop_rx()  local
543 	__ssp_disable_rxwm(ssp);  in sifive_serial_stop_rx()
548 	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);  in sifive_serial_start_tx()  local
550 	__ssp_enable_txwm(ssp);  in sifive_serial_start_tx()
555 	struct sifive_serial_port *ssp = dev_id;  in sifive_serial_irq()  local
558 	spin_lock(&ssp->port.lock);  in sifive_serial_irq()
560 	ip = __ssp_readl(ssp, SIFIVE_SERIAL_IP_OFFS);  in sifive_serial_irq()
562 		spin_unlock(&ssp->port.lock);  in sifive_serial_irq()
567 		__ssp_receive_chars(ssp);  in sifive_serial_irq()
569 		__ssp_transmit_chars(ssp);  in sifive_serial_irq()
571 	spin_unlock(&ssp->port.lock);  in sifive_serial_irq()
598 	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);  in sifive_serial_startup()  local
600 	__ssp_enable_rxwm(ssp);  in sifive_serial_startup()
607 	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);  in sifive_serial_shutdown()  local
609 	__ssp_disable_rxwm(ssp);  in sifive_serial_shutdown()
610 	__ssp_disable_txwm(ssp);  in sifive_serial_shutdown()
630 	struct sifive_serial_port *ssp = notifier_to_sifive_serial_port(nb);  in sifive_serial_clk_notifier()  local
639 		__ssp_wait_for_xmitr(ssp);  in sifive_serial_clk_notifier()
649 		udelay(DIV_ROUND_UP(12 * 1000 * 1000, ssp->baud_rate));  in sifive_serial_clk_notifier()
652 	if (event == POST_RATE_CHANGE && ssp->clkin_rate != cnd->new_rate) {  in sifive_serial_clk_notifier()
653 		ssp->clkin_rate = cnd->new_rate;  in sifive_serial_clk_notifier()
654 		__ssp_update_div(ssp);  in sifive_serial_clk_notifier()
664 	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);  in sifive_serial_set_termios()  local
671 		dev_err_once(ssp->port.dev, "only 8-bit words supported\n");  in sifive_serial_set_termios()
673 		dev_err_once(ssp->port.dev, "parity checking not supported\n");  in sifive_serial_set_termios()
675 		dev_err_once(ssp->port.dev, "BREAK detection not supported\n");  in sifive_serial_set_termios()
679 	__ssp_set_stop_bits(ssp, nstop);  in sifive_serial_set_termios()
682 	rate = uart_get_baud_rate(port, termios, old, 0, ssp->clkin_rate / 16);  in sifive_serial_set_termios()
683 	__ssp_update_baud_rate(ssp, rate);  in sifive_serial_set_termios()
685 	spin_lock_irqsave(&ssp->port.lock, flags);  in sifive_serial_set_termios()
690 	ssp->port.read_status_mask = 0;  in sifive_serial_set_termios()
693 	v = __ssp_readl(ssp, SIFIVE_SERIAL_RXCTRL_OFFS);  in sifive_serial_set_termios()
700 		__ssp_writel(v, SIFIVE_SERIAL_RXCTRL_OFFS, ssp);  in sifive_serial_set_termios()
702 	spin_unlock_irqrestore(&ssp->port.lock, flags);  in sifive_serial_set_termios()
716 	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);  in sifive_serial_config_port()  local
718 	ssp->port.type = PORT_SIFIVE_V0;  in sifive_serial_config_port()
735 	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);  in sifive_serial_poll_get_char()  local
738 	ch = __ssp_receive_char(ssp, &is_empty);  in sifive_serial_poll_get_char()
748 	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);  in sifive_serial_poll_put_char()  local
750 	__ssp_wait_for_xmitr(ssp);  in sifive_serial_poll_put_char()
751 	__ssp_transmit_char(ssp, c);  in sifive_serial_poll_put_char()
806 	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);  in sifive_serial_console_putchar()  local
808 	__ssp_wait_for_xmitr(ssp);  in sifive_serial_console_putchar()
809 	__ssp_transmit_char(ssp, ch);  in sifive_serial_console_putchar()
815 	struct sifive_serial_port *ssp = sifive_serial_console_ports[co->index];  in sifive_serial_console_write()  local
820 	if (!ssp)  in sifive_serial_console_write()
824 	if (ssp->port.sysrq)  in sifive_serial_console_write()
827 		locked = spin_trylock(&ssp->port.lock);  in sifive_serial_console_write()
829 		spin_lock(&ssp->port.lock);  in sifive_serial_console_write()
831 	ier = __ssp_readl(ssp, SIFIVE_SERIAL_IE_OFFS);  in sifive_serial_console_write()
832 	__ssp_writel(0, SIFIVE_SERIAL_IE_OFFS, ssp);  in sifive_serial_console_write()
834 	uart_console_write(&ssp->port, s, count, sifive_serial_console_putchar);  in sifive_serial_console_write()
836 	__ssp_writel(ier, SIFIVE_SERIAL_IE_OFFS, ssp);  in sifive_serial_console_write()
839 		spin_unlock(&ssp->port.lock);  in sifive_serial_console_write()
845 	struct sifive_serial_port *ssp;  in sifive_serial_console_setup()  local
854 	ssp = sifive_serial_console_ports[co->index];  in sifive_serial_console_setup()
855 	if (!ssp)  in sifive_serial_console_setup()
861 	return uart_set_options(&ssp->port, co, baud, parity, bits, flow);  in sifive_serial_console_setup()
884 static void __ssp_add_console_port(struct sifive_serial_port *ssp)  in __ssp_add_console_port()  argument
886 	sifive_serial_console_ports[ssp->port.line] = ssp;  in __ssp_add_console_port()
889 static void __ssp_remove_console_port(struct sifive_serial_port *ssp)  in __ssp_remove_console_port()  argument
891 	sifive_serial_console_ports[ssp->port.line] = 0;  in __ssp_remove_console_port()
900 static void __ssp_add_console_port(struct sifive_serial_port *ssp)  in __ssp_add_console_port()  argument
902 static void __ssp_remove_console_port(struct sifive_serial_port *ssp)  in __ssp_remove_console_port()  argument
939 	struct sifive_serial_port *ssp;  in sifive_serial_probe()  local
975 	ssp = devm_kzalloc(&pdev->dev, sizeof(*ssp), GFP_KERNEL);  in sifive_serial_probe()
976 	if (!ssp)  in sifive_serial_probe()
979 	ssp->port.dev = &pdev->dev;  in sifive_serial_probe()
980 	ssp->port.type = PORT_SIFIVE_V0;  in sifive_serial_probe()
981 	ssp->port.iotype = UPIO_MEM;  in sifive_serial_probe()
982 	ssp->port.irq = irq;  in sifive_serial_probe()
983 	ssp->port.fifosize = SIFIVE_TX_FIFO_DEPTH;  in sifive_serial_probe()
984 	ssp->port.ops = &sifive_serial_uops;  in sifive_serial_probe()
985 	ssp->port.line = id;  in sifive_serial_probe()
986 	ssp->port.mapbase = mem->start;  in sifive_serial_probe()
987 	ssp->port.membase = base;  in sifive_serial_probe()
988 	ssp->dev = &pdev->dev;  in sifive_serial_probe()
989 	ssp->clk = clk;  in sifive_serial_probe()
990 	ssp->clk_notifier.notifier_call = sifive_serial_clk_notifier;  in sifive_serial_probe()
992 	r = clk_notifier_register(ssp->clk, &ssp->clk_notifier);  in sifive_serial_probe()
1000 	ssp->clkin_rate = clk_get_rate(ssp->clk);  in sifive_serial_probe()
1001 	ssp->baud_rate = SIFIVE_DEFAULT_BAUD_RATE;  in sifive_serial_probe()
1002 	__ssp_update_div(ssp);  in sifive_serial_probe()
1004 	platform_set_drvdata(pdev, ssp);  in sifive_serial_probe()
1009 		     SIFIVE_SERIAL_TXCTRL_OFFS, ssp);  in sifive_serial_probe()
1014 		     SIFIVE_SERIAL_RXCTRL_OFFS, ssp);  in sifive_serial_probe()
1016 	r = request_irq(ssp->port.irq, sifive_serial_irq, ssp->port.irqflags,  in sifive_serial_probe()
1017 			dev_name(&pdev->dev), ssp);  in sifive_serial_probe()
1023 	__ssp_add_console_port(ssp);  in sifive_serial_probe()
1025 	r = uart_add_one_port(&sifive_serial_uart_driver, &ssp->port);  in sifive_serial_probe()
1034 	__ssp_remove_console_port(ssp);  in sifive_serial_probe()
1035 	free_irq(ssp->port.irq, ssp);  in sifive_serial_probe()
1037 	clk_notifier_unregister(ssp->clk, &ssp->clk_notifier);  in sifive_serial_probe()
1044 	struct sifive_serial_port *ssp = platform_get_drvdata(dev);  in sifive_serial_remove()  local
1046 	__ssp_remove_console_port(ssp);  in sifive_serial_remove()
1047 	uart_remove_one_port(&sifive_serial_uart_driver, &ssp->port);  in sifive_serial_remove()
1048 	free_irq(ssp->port.irq, ssp);  in sifive_serial_remove()
1049 	clk_notifier_unregister(ssp->clk, &ssp->clk_notifier);  in sifive_serial_remove()