1 files changed, 135 insertions, 90 deletions

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index cf2c890a560f..04212c823a91 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -248,6 +248,13 @@ struct pl011_dmatx_data {
 	bool			queued;
 };
 
+enum pl011_rs485_tx_state {
+	OFF,
+	WAIT_AFTER_RTS,
+	SEND,
+	WAIT_AFTER_SEND,
+};
+
 /*
  * We wrap our port structure around the generic uart_port.
  */
@@ -256,16 +263,18 @@ struct uart_amba_port {
 	const u16		*reg_offset;
 	struct clk		*clk;
 	const struct vendor_data *vendor;
-	unsigned int		dmacr;		/* dma control reg */
 	unsigned int		im;		/* interrupt mask */
 	unsigned int		old_status;
 	unsigned int		fifosize;	/* vendor-specific */
 	unsigned int		fixed_baud;	/* vendor-set fixed baud rate */
 	char			type[12];
-	bool			rs485_tx_started;
-	unsigned int		rs485_tx_drain_interval; /* usecs */
+	ktime_t			rs485_tx_drain_interval; /* nano */
+	enum pl011_rs485_tx_state	rs485_tx_state;
+	struct hrtimer		trigger_start_tx;
+	struct hrtimer		trigger_stop_tx;
 #ifdef CONFIG_DMA_ENGINE
 	/* DMA stuff */
+	unsigned int		dmacr;		/* dma control reg */
 	bool			using_tx_dma;
 	bool			using_rx_dma;
 	struct pl011_dmarx_data dmarx;
@@ -348,10 +357,7 @@ static int pl011_fifo_to_tty(struct uart_amba_port *uap)
 				flag = TTY_FRAME;
 		}
 
-		uart_port_unlock(&uap->port);
-		sysrq = uart_handle_sysrq_char(&uap->port, ch & 255);
-		uart_port_lock(&uap->port);
-
+		sysrq = uart_prepare_sysrq_char(&uap->port, ch & 255);
 		if (!sysrq)
 			uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag);
 	}
@@ -538,6 +544,7 @@ static void pl011_start_tx_pio(struct uart_amba_port *uap);
 static void pl011_dma_tx_callback(void *data)
 {
 	struct uart_amba_port *uap = data;
+	struct tty_port *tport = &uap->port.state->port;
 	struct pl011_dmatx_data *dmatx = &uap->dmatx;
 	unsigned long flags;
 	u16 dmacr;
@@ -561,7 +568,7 @@ static void pl011_dma_tx_callback(void *data)
 	 * get further refills (hence we check dmacr).
 	 */
 	if (!(dmacr & UART011_TXDMAE) || uart_tx_stopped(&uap->port) ||
-	    uart_circ_empty(&uap->port.state->xmit)) {
+	    kfifo_is_empty(&tport->xmit_fifo)) {
 		uap->dmatx.queued = false;
 		uart_port_unlock_irqrestore(&uap->port, flags);
 		return;
@@ -591,7 +598,7 @@ static int pl011_dma_tx_refill(struct uart_amba_port *uap)
 	struct dma_chan *chan = dmatx->chan;
 	struct dma_device *dma_dev = chan->device;
 	struct dma_async_tx_descriptor *desc;
-	struct circ_buf *xmit = &uap->port.state->xmit;
+	struct tty_port *tport = &uap->port.state->port;
 	unsigned int count;
 
 	/*
@@ -600,7 +607,7 @@ static int pl011_dma_tx_refill(struct uart_amba_port *uap)
 	 * the standard interrupt handling.  This ensures that we
 	 * issue a uart_write_wakeup() at the appropriate time.
 	 */
-	count = uart_circ_chars_pending(xmit);
+	count = kfifo_len(&tport->xmit_fifo);
 	if (count < (uap->fifosize >> 1)) {
 		uap->dmatx.queued = false;
 		return 0;
@@ -616,21 +623,7 @@ static int pl011_dma_tx_refill(struct uart_amba_port *uap)
 	if (count > PL011_DMA_BUFFER_SIZE)
 		count = PL011_DMA_BUFFER_SIZE;
 
-	if (xmit->tail < xmit->head) {
-		memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], count);
-	} else {
-		size_t first = UART_XMIT_SIZE - xmit->tail;
-		size_t second;
-
-		if (first > count)
-			first = count;
-		second = count - first;
-
-		memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], first);
-		if (second)
-			memcpy(&dmatx->buf[first], &xmit->buf[0], second);
-	}
-
+	count = kfifo_out_peek(&tport->xmit_fifo, dmatx->buf, count);
 	dmatx->len = count;
 	dmatx->dma = dma_map_single(dma_dev->dev, dmatx->buf, count,
 				    DMA_TO_DEVICE);
@@ -673,7 +666,7 @@ static int pl011_dma_tx_refill(struct uart_amba_port *uap)
 	 */
 	uart_xmit_advance(&uap->port, count);
 
-	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
 		uart_write_wakeup(&uap->port);
 
 	return 1;
@@ -1017,7 +1010,7 @@ static void pl011_dma_rx_callback(void *data)
 	ret = pl011_dma_rx_trigger_dma(uap);
 
 	pl011_dma_rx_chars(uap, pending, lastbuf, false);
-	uart_port_unlock_irq(&uap->port);
+	uart_unlock_and_check_sysrq(&uap->port);
 	/*
 	 * Do this check after we picked the DMA chars so we don't
 	 * get some IRQ immediately from RX.
@@ -1276,30 +1269,31 @@ static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
 
 static void pl011_rs485_tx_stop(struct uart_amba_port *uap)
 {
-	/*
-	 * To be on the safe side only time out after twice as many iterations
-	 * as fifo size.
-	 */
-	const int MAX_TX_DRAIN_ITERS = uap->port.fifosize * 2;
 	struct uart_port *port = &uap->port;
-	int i = 0;
 	u32 cr;
 
-	/* Wait until hardware tx queue is empty */
-	while (!pl011_tx_empty(port)) {
-		if (i > MAX_TX_DRAIN_ITERS) {
-			dev_warn(port->dev,
-				 "timeout while draining hardware tx queue\n");
-			break;
-		}
+	if (uap->rs485_tx_state == SEND)
+		uap->rs485_tx_state = WAIT_AFTER_SEND;
 
-		udelay(uap->rs485_tx_drain_interval);
-		i++;
+	if (uap->rs485_tx_state == WAIT_AFTER_SEND) {
+		/* Schedule hrtimer if tx queue not empty */
+		if (!pl011_tx_empty(port)) {
+			hrtimer_start(&uap->trigger_stop_tx,
+				      uap->rs485_tx_drain_interval,
+				      HRTIMER_MODE_REL);
+			return;
+		}
+		if (port->rs485.delay_rts_after_send > 0) {
+			hrtimer_start(&uap->trigger_stop_tx,
+				      ms_to_ktime(port->rs485.delay_rts_after_send),
+				      HRTIMER_MODE_REL);
+			return;
+		}
+		/* Continue without any delay */
+	} else if (uap->rs485_tx_state == WAIT_AFTER_RTS) {
+		hrtimer_try_to_cancel(&uap->trigger_start_tx);
 	}
 
-	if (port->rs485.delay_rts_after_send)
-		mdelay(port->rs485.delay_rts_after_send);
-
 	cr = pl011_read(uap, REG_CR);
 
 	if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
@@ -1312,7 +1306,7 @@ static void pl011_rs485_tx_stop(struct uart_amba_port *uap)
 	cr |= UART011_CR_RXE;
 	pl011_write(cr, uap, REG_CR);
 
-	uap->rs485_tx_started = false;
+	uap->rs485_tx_state = OFF;
 }
 
 static void pl011_stop_tx(struct uart_port *port)
@@ -1320,11 +1314,18 @@ static void pl011_stop_tx(struct uart_port *port)
 	struct uart_amba_port *uap =
 	    container_of(port, struct uart_amba_port, port);
 
+	if (port->rs485.flags & SER_RS485_ENABLED &&
+	    uap->rs485_tx_state == WAIT_AFTER_RTS) {
+		pl011_rs485_tx_stop(uap);
+		return;
+	}
+
 	uap->im &= ~UART011_TXIM;
 	pl011_write(uap->im, uap, REG_IMSC);
 	pl011_dma_tx_stop(uap);
 
-	if ((port->rs485.flags & SER_RS485_ENABLED) && uap->rs485_tx_started)
+	if (port->rs485.flags & SER_RS485_ENABLED &&
+	    uap->rs485_tx_state != OFF)
 		pl011_rs485_tx_stop(uap);
 }
 
@@ -1344,10 +1345,19 @@ static void pl011_rs485_tx_start(struct uart_amba_port *uap)
 	struct uart_port *port = &uap->port;
 	u32 cr;
 
+	if (uap->rs485_tx_state == WAIT_AFTER_RTS) {
+		uap->rs485_tx_state = SEND;
+		return;
+	}
+	if (uap->rs485_tx_state == WAIT_AFTER_SEND) {
+		hrtimer_try_to_cancel(&uap->trigger_stop_tx);
+		uap->rs485_tx_state = SEND;
+		return;
+	}
+	/* uap->rs485_tx_state == OFF */
 	/* Enable transmitter */
 	cr = pl011_read(uap, REG_CR);
 	cr |= UART011_CR_TXE;
-
 	/* Disable receiver if half-duplex */
 	if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
 		cr &= ~UART011_CR_RXE;
@@ -1359,10 +1369,14 @@ static void pl011_rs485_tx_start(struct uart_amba_port *uap)
 
 	pl011_write(cr, uap, REG_CR);
 
-	if (port->rs485.delay_rts_before_send)
-		mdelay(port->rs485.delay_rts_before_send);
-
-	uap->rs485_tx_started = true;
+	if (port->rs485.delay_rts_before_send > 0) {
+		uap->rs485_tx_state = WAIT_AFTER_RTS;
+		hrtimer_start(&uap->trigger_start_tx,
+			      ms_to_ktime(port->rs485.delay_rts_before_send),
+			      HRTIMER_MODE_REL);
+	} else {
+		uap->rs485_tx_state = SEND;
+	}
 }
 
 static void pl011_start_tx(struct uart_port *port)
@@ -1371,13 +1385,44 @@ static void pl011_start_tx(struct uart_port *port)
 	    container_of(port, struct uart_amba_port, port);
 
 	if ((uap->port.rs485.flags & SER_RS485_ENABLED) &&
-	    !uap->rs485_tx_started)
+	    uap->rs485_tx_state != SEND) {
 		pl011_rs485_tx_start(uap);
+		if (uap->rs485_tx_state == WAIT_AFTER_RTS)
+			return;
+	}
 
 	if (!pl011_dma_tx_start(uap))
 		pl011_start_tx_pio(uap);
 }
 
+static enum hrtimer_restart pl011_trigger_start_tx(struct hrtimer *t)
+{
+	struct uart_amba_port *uap =
+	    container_of(t, struct uart_amba_port, trigger_start_tx);
+	unsigned long flags;
+
+	uart_port_lock_irqsave(&uap->port, &flags);
+	if (uap->rs485_tx_state == WAIT_AFTER_RTS)
+		pl011_start_tx(&uap->port);
+	uart_port_unlock_irqrestore(&uap->port, flags);
+
+	return HRTIMER_NORESTART;
+}
+
+static enum hrtimer_restart pl011_trigger_stop_tx(struct hrtimer *t)
+{
+	struct uart_amba_port *uap =
+	    container_of(t, struct uart_amba_port, trigger_stop_tx);
+	unsigned long flags;
+
+	uart_port_lock_irqsave(&uap->port, &flags);
+	if (uap->rs485_tx_state == WAIT_AFTER_SEND)
+		pl011_rs485_tx_stop(uap);
+	uart_port_unlock_irqrestore(&uap->port, flags);
+
+	return HRTIMER_NORESTART;
+}
+
 static void pl011_stop_rx(struct uart_port *port)
 {
 	struct uart_amba_port *uap =
@@ -1457,7 +1502,7 @@ static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c,
 /* Returns true if tx interrupts have to be (kept) enabled  */
 static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq)
 {
-	struct circ_buf *xmit = &uap->port.state->xmit;
+	struct tty_port *tport = &uap->port.state->port;
 	int count = uap->fifosize >> 1;
 
 	if (uap->port.x_char) {
@@ -1466,7 +1511,7 @@ static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq)
 		uap->port.x_char = 0;
 		--count;
 	}
-	if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
+	if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(&uap->port)) {
 		pl011_stop_tx(&uap->port);
 		return false;
 	}
@@ -1475,20 +1520,25 @@ static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq)
 	if (pl011_dma_tx_irq(uap))
 		return true;
 
-	do {
+	while (1) {
+		unsigned char c;
+
 		if (likely(from_irq) && count-- == 0)
 			break;
 
-		if (!pl011_tx_char(uap, xmit->buf[xmit->tail], from_irq))
+		if (!kfifo_peek(&tport->xmit_fifo, &c))
+			break;
+
+		if (!pl011_tx_char(uap, c, from_irq))
 			break;
 
-		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
-	} while (!uart_circ_empty(xmit));
+		kfifo_skip(&tport->xmit_fifo);
+	}
 
-	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
 		uart_write_wakeup(&uap->port);
 
-	if (uart_circ_empty(xmit)) {
+	if (kfifo_is_empty(&tport->xmit_fifo)) {
 		pl011_stop_tx(&uap->port);
 		return false;
 	}
@@ -1540,11 +1590,10 @@ static void check_apply_cts_event_workaround(struct uart_amba_port *uap)
 static irqreturn_t pl011_int(int irq, void *dev_id)
 {
 	struct uart_amba_port *uap = dev_id;
-	unsigned long flags;
 	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
 	int handled = 0;
 
-	uart_port_lock_irqsave(&uap->port, &flags);
+	uart_port_lock(&uap->port);
 	status = pl011_read(uap, REG_RIS) & uap->im;
 	if (status) {
 		do {
@@ -1573,7 +1622,7 @@ static irqreturn_t pl011_int(int irq, void *dev_id)
 		handled = 1;
 	}
 
-	uart_port_unlock_irqrestore(&uap->port, flags);
+	uart_unlock_and_check_sysrq(&uap->port);
 
 	return IRQ_RETVAL(handled);
 }
@@ -1831,6 +1880,13 @@ static void pl011_unthrottle_rx(struct uart_port *port)
 
 	pl011_write(uap->im, uap, REG_IMSC);
 
+#ifdef CONFIG_DMA_ENGINE
+	if (uap->using_rx_dma) {
+		uap->dmacr |= UART011_RXDMAE;
+		pl011_write(uap->dmacr, uap, REG_DMACR);
+	}
+#endif
+
 	uart_port_unlock_irqrestore(&uap->port, flags);
 }
 
@@ -1958,7 +2014,7 @@ static void pl011_shutdown(struct uart_port *port)
 
 	pl011_dma_shutdown(uap);
 
-	if ((port->rs485.flags & SER_RS485_ENABLED) && uap->rs485_tx_started)
+	if ((port->rs485.flags & SER_RS485_ENABLED && uap->rs485_tx_state != OFF))
 		pl011_rs485_tx_stop(uap);
 
 	free_irq(uap->port.irq, uap);
@@ -2103,7 +2159,7 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
 	 * with the given baud rate. We use this as the poll interval when we
 	 * wait for the tx queue to empty.
 	 */
-	uap->rs485_tx_drain_interval = DIV_ROUND_UP(bits * 1000 * 1000, baud);
+	uap->rs485_tx_drain_interval = ns_to_ktime(DIV_ROUND_UP(bits * NSEC_PER_SEC, baud));
 
 	pl011_setup_status_masks(port, termios);
 
@@ -2214,7 +2270,7 @@ static int pl011_verify_port(struct uart_port *port, struct serial_struct *ser)
 
 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
 		ret = -EINVAL;
-	if (ser->irq < 0 || ser->irq >= nr_irqs)
+	if (ser->irq < 0 || ser->irq >= irq_get_nr_irqs())
 		ret = -EINVAL;
 	if (ser->baud_base < 9600)
 		ret = -EINVAL;
@@ -2322,13 +2378,10 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
 
 	clk_enable(uap->clk);
 
-	local_irq_save(flags);
-	if (uap->port.sysrq)
-		locked = 0;
-	else if (oops_in_progress)
-		locked = uart_port_trylock(&uap->port);
+	if (oops_in_progress)
+		locked = uart_port_trylock_irqsave(&uap->port, &flags);
 	else
-		uart_port_lock(&uap->port);
+		uart_port_lock_irqsave(&uap->port, &flags);
 
 	/*
 	 *	First save the CR then disable the interrupts
@@ -2354,8 +2407,7 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
 		pl011_write(old_cr, uap, REG_CR);
 
 	if (locked)
-		uart_port_unlock(&uap->port);
-	local_irq_restore(flags);
+		uart_port_unlock_irqrestore(&uap->port, flags);
 
 	clk_disable(uap->clk);
 }
@@ -2496,7 +2548,7 @@ static int pl011_console_match(struct console *co, char *name, int idx,
 			continue;
 
 		co->index = i;
-		port->cons = co;
+		uart_port_set_cons(port, co);
 		return pl011_console_setup(co, options);
 	}
 
@@ -2708,18 +2760,6 @@ static int pl011_find_free_port(void)
 	return -EBUSY;
 }
 
-static int pl011_get_rs485_mode(struct uart_amba_port *uap)
-{
-	struct uart_port *port = &uap->port;
-	int ret;
-
-	ret = uart_get_rs485_mode(port);
-	if (ret)
-		return ret;
-
-	return 0;
-}
-
 static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap,
 			    struct resource *mmiobase, int index)
 {
@@ -2740,7 +2780,7 @@ static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap,
 	uap->port.flags = UPF_BOOT_AUTOCONF;
 	uap->port.line = index;
 
-	ret = pl011_get_rs485_mode(uap);
+	ret = uart_get_rs485_mode(&uap->port);
 	if (ret)
 		return ret;
 
@@ -2828,6 +2868,11 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 		}
 	}
 
+	hrtimer_init(&uap->trigger_start_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_init(&uap->trigger_stop_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	uap->trigger_start_tx.function = pl011_trigger_start_tx;
+	uap->trigger_stop_tx.function = pl011_trigger_stop_tx;
+
 	ret = pl011_setup_port(&dev->dev, uap, &dev->res, portnr);
 	if (ret)
 		return ret;
@@ -2965,7 +3010,7 @@ MODULE_DEVICE_TABLE(acpi, sbsa_uart_acpi_match);
 
 static struct platform_driver arm_sbsa_uart_platform_driver = {
 	.probe		= sbsa_uart_probe,
-	.remove_new	= sbsa_uart_remove,
+	.remove		= sbsa_uart_remove,
 	.driver	= {
 		.name	= "sbsa-uart",
 		.pm	= &pl011_dev_pm_ops,