1 files changed, 54 insertions, 89 deletions

diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index e55615eb34a..86de4477d98 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -32,14 +32,14 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/io.h>
-#include <linux/pinctrl/consumer.h>
 #include <linux/of_device.h>
 #include <linux/dma-mapping.h>
-#include <linux/fsl/mxs-dma.h>
+#include <linux/dmaengine.h>
 
 #include <asm/cacheflush.h>
 
 #define MXS_AUART_PORTS 5
+#define MXS_AUART_FIFO_SIZE		16
 
 #define AUART_CTRL0			0x00000000
 #define AUART_CTRL0_SET			0x00000004
@@ -134,10 +134,10 @@ enum mxs_auart_type {
 struct mxs_auart_port {
 	struct uart_port port;
 
-#define MXS_AUART_DMA_CONFIG	0x1
 #define MXS_AUART_DMA_ENABLED	0x2
 #define MXS_AUART_DMA_TX_SYNC	2  /* bit 2 */
 #define MXS_AUART_DMA_RX_READY	3  /* bit 3 */
+#define MXS_AUART_RTSCTS	4  /* bit 4 */
 	unsigned long flags;
 	unsigned int ctrl;
 	enum mxs_auart_type devtype;
@@ -148,11 +148,6 @@ struct mxs_auart_port {
 	struct device *dev;
 
 	/* for DMA */
-	struct mxs_dma_data dma_data;
-	int dma_channel_rx, dma_channel_tx;
-	int dma_irq_rx, dma_irq_tx;
-	int dma_channel;
-
 	struct scatterlist tx_sgl;
 	struct dma_chan	*tx_dma_chan;
 	void *tx_dma_buf;
@@ -205,7 +200,7 @@ static void dma_tx_callback(void *param)
 
 	/* clear the bit used to serialize the DMA tx. */
 	clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags);
-	smp_mb__after_clear_bit();
+	smp_mb__after_atomic();
 
 	/* wake up the possible processes. */
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
@@ -280,7 +275,7 @@ static void mxs_auart_tx_chars(struct mxs_auart_port *s)
 			mxs_auart_dma_tx(s, i);
 		} else {
 			clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags);
-			smp_mb__after_clear_bit();
+			smp_mb__after_atomic();
 		}
 		return;
 	}
@@ -364,7 +359,6 @@ out:
 
 static void mxs_auart_rx_chars(struct mxs_auart_port *s)
 {
-	struct tty_struct *tty = s->port.state->port.tty;
 	u32 stat = 0;
 
 	for (;;) {
@@ -375,7 +369,7 @@ static void mxs_auart_rx_chars(struct mxs_auart_port *s)
 	}
 
 	writel(stat, s->port.membase + AUART_STAT);
-	tty_flip_buffer_push(tty);
+	tty_flip_buffer_push(&s->port.state->port);
 }
 
 static int mxs_auart_request_port(struct uart_port *u)
@@ -441,25 +435,11 @@ static u32 mxs_auart_get_mctrl(struct uart_port *u)
 	return mctrl;
 }
 
-static bool mxs_auart_dma_filter(struct dma_chan *chan, void *param)
-{
-	struct mxs_auart_port *s = param;
-
-	if (!mxs_dma_is_apbx(chan))
-		return false;
-
-	if (s->dma_channel == chan->chan_id) {
-		chan->private = &s->dma_data;
-		return true;
-	}
-	return false;
-}
-
 static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s);
 static void dma_rx_callback(void *arg)
 {
 	struct mxs_auart_port *s = (struct mxs_auart_port *) arg;
-	struct tty_struct *tty = s->port.state->port.tty;
+	struct tty_port *port = &s->port.state->port;
 	int count;
 	u32 stat;
 
@@ -470,10 +450,10 @@ static void dma_rx_callback(void *arg)
 			AUART_STAT_PERR | AUART_STAT_FERR);
 
 	count = stat & AUART_STAT_RXCOUNT_MASK;
-	tty_insert_flip_string(tty, s->rx_dma_buf, count);
+	tty_insert_flip_string(port, s->rx_dma_buf, count);
 
 	writel(stat, s->port.membase + AUART_STAT);
-	tty_flip_buffer_push(tty);
+	tty_flip_buffer_push(port);
 
 	/* start the next DMA for RX. */
 	mxs_auart_dma_prep_rx(s);
@@ -546,21 +526,11 @@ static void mxs_auart_dma_exit(struct mxs_auart_port *s)
 
 static int mxs_auart_dma_init(struct mxs_auart_port *s)
 {
-	dma_cap_mask_t mask;
-
 	if (auart_dma_enabled(s))
 		return 0;
 
-	/* We do not get the right DMA channels. */
-	if (s->dma_channel_rx == -1 || s->dma_channel_rx == -1)
-		return -EINVAL;
-
 	/* init for RX */
-	dma_cap_zero(mask);
-	dma_cap_set(DMA_SLAVE, mask);
-	s->dma_channel = s->dma_channel_rx;
-	s->dma_data.chan_irq = s->dma_irq_rx;
-	s->rx_dma_chan = dma_request_channel(mask, mxs_auart_dma_filter, s);
+	s->rx_dma_chan = dma_request_slave_channel(s->dev, "rx");
 	if (!s->rx_dma_chan)
 		goto err_out;
 	s->rx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);
@@ -568,9 +538,7 @@ static int mxs_auart_dma_init(struct mxs_auart_port *s)
 		goto err_out;
 
 	/* init for TX */
-	s->dma_channel = s->dma_channel_tx;
-	s->dma_data.chan_irq = s->dma_irq_tx;
-	s->tx_dma_chan = dma_request_channel(mask, mxs_auart_dma_filter, s);
+	s->tx_dma_chan = dma_request_slave_channel(s->dev, "tx");
 	if (!s->tx_dma_chan)
 		goto err_out;
 	s->tx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);
@@ -581,6 +549,9 @@ static int mxs_auart_dma_init(struct mxs_auart_port *s)
 	s->flags |= MXS_AUART_DMA_ENABLED;
 	dev_dbg(s->dev, "enabled the DMA support.");
 
+	/* The DMA buffer is now the FIFO the TTY subsystem can use */
+	s->port.fifosize = UART_XMIT_SIZE;
+
 	return 0;
 
 err_out:
@@ -633,7 +604,7 @@ static void mxs_auart_settermios(struct uart_port *u,
 
 	if (termios->c_iflag & INPCK)
 		u->read_status_mask |= AUART_STAT_PERR;
-	if (termios->c_iflag & (BRKINT | PARMRK))
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
 		u->read_status_mask |= AUART_STAT_BERR;
 
 	/*
@@ -672,7 +643,8 @@ static void mxs_auart_settermios(struct uart_port *u,
 		 * we can only implement the DMA support for auart
 		 * in mx28.
 		 */
-		if (is_imx28_auart(s) && (s->flags & MXS_AUART_DMA_CONFIG)) {
+		if (is_imx28_auart(s)
+				&& test_bit(MXS_AUART_RTSCTS, &s->flags)) {
 			if (!mxs_auart_dma_init(s))
 				/* enable DMA tranfer */
 				ctrl2 |= AUART_CTRL2_TXDMAE | AUART_CTRL2_RXDMAE
@@ -710,11 +682,18 @@ static void mxs_auart_settermios(struct uart_port *u,
 
 static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
 {
-	u32 istatus, istat;
+	u32 istat;
 	struct mxs_auart_port *s = context;
 	u32 stat = readl(s->port.membase + AUART_STAT);
 
-	istatus = istat = readl(s->port.membase + AUART_INTR);
+	istat = readl(s->port.membase + AUART_INTR);
+
+	/* ack irq */
+	writel(istat & (AUART_INTR_RTIS
+		| AUART_INTR_TXIS
+		| AUART_INTR_RXIS
+		| AUART_INTR_CTSMIS),
+			s->port.membase + AUART_INTR_CLR);
 
 	if (istat & AUART_INTR_CTSMIS) {
 		uart_handle_cts_change(&s->port, stat & AUART_STAT_CTS);
@@ -734,12 +713,6 @@ static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
 		istat &= ~AUART_INTR_TXIS;
 	}
 
-	writel(istatus & (AUART_INTR_RTIS
-		| AUART_INTR_TXIS
-		| AUART_INTR_RXIS
-		| AUART_INTR_CTSMIS),
-			s->port.membase + AUART_INTR_CLR);
-
 	return IRQ_HANDLED;
 }
 
@@ -761,9 +734,12 @@ static void mxs_auart_reset(struct uart_port *u)
 
 static int mxs_auart_startup(struct uart_port *u)
 {
+	int ret;
 	struct mxs_auart_port *s = to_auart_port(u);
 
-	clk_prepare_enable(s->clk);
+	ret = clk_prepare_enable(s->clk);
+	if (ret)
+		return ret;
 
 	writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR);
 
@@ -772,6 +748,9 @@ static int mxs_auart_startup(struct uart_port *u)
 	writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN,
 			u->membase + AUART_INTR);
 
+	/* Reset FIFO size (it could have changed if DMA was enabled) */
+	u->fifosize = MXS_AUART_FIFO_SIZE;
+
 	/*
 	 * Enable fifo so all four bytes of a DMA word are written to
 	 * output (otherwise, only the LSB is written, ie. 1 in 4 bytes)
@@ -882,9 +861,9 @@ auart_console_write(struct console *co, const char *str, unsigned int count)
 	struct mxs_auart_port *s;
 	struct uart_port *port;
 	unsigned int old_ctrl0, old_ctrl2;
-	unsigned int to = 1000;
+	unsigned int to = 20000;
 
-	if (co->index >	MXS_AUART_PORTS || co->index < 0)
+	if (co->index >= MXS_AUART_PORTS || co->index < 0)
 		return;
 
 	s = auart_port[co->index];
@@ -903,18 +882,23 @@ auart_console_write(struct console *co, const char *str, unsigned int count)
 
 	uart_console_write(port, str, count, mxs_auart_console_putchar);
 
-	/*
-	 * Finally, wait for transmitter to become empty
-	 * and restore the TCR
-	 */
+	/* Finally, wait for transmitter to become empty ... */
 	while (readl(port->membase + AUART_STAT) & AUART_STAT_BUSY) {
+		udelay(1);
 		if (!to--)
 			break;
-		udelay(1);
 	}
 
-	writel(old_ctrl0, port->membase + AUART_CTRL0);
-	writel(old_ctrl2, port->membase + AUART_CTRL2);
+	/*
+	 * ... and restore the TCR if we waited long enough for the transmitter
+	 * to be idle. This might keep the transmitter enabled although it is
+	 * unused, but that is better than to disable it while it is still
+	 * transmitting.
+	 */
+	if (!(readl(port->membase + AUART_STAT) & AUART_STAT_BUSY)) {
+		writel(old_ctrl0, port->membase + AUART_CTRL0);
+		writel(old_ctrl2, port->membase + AUART_CTRL2);
+	}
 
 	clk_disable(s->clk);
 }
@@ -976,7 +960,9 @@ auart_console_setup(struct console *co, char *options)
 	if (!s)
 		return -ENODEV;
 
-	clk_prepare_enable(s->clk);
+	ret = clk_prepare_enable(s->clk);
+	if (ret)
+		return ret;
 
 	if (options)
 		uart_parse_options(options, &baud, &parity, &bits, &flow);
@@ -1021,7 +1007,6 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s,
 		struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
-	u32 dma_channel[2];
 	int ret;
 
 	if (!np)
@@ -1035,20 +1020,9 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s,
 	}
 	s->port.line = ret;
 
-	s->dma_irq_rx = platform_get_irq(pdev, 1);
-	s->dma_irq_tx = platform_get_irq(pdev, 2);
-
-	ret = of_property_read_u32_array(np, "fsl,auart-dma-channel",
-					dma_channel, 2);
-	if (ret == 0) {
-		s->dma_channel_rx = dma_channel[0];
-		s->dma_channel_tx = dma_channel[1];
+	if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
+		set_bit(MXS_AUART_RTSCTS, &s->flags);
 
-		s->flags |= MXS_AUART_DMA_CONFIG;
-	} else {
-		s->dma_channel_rx = -1;
-		s->dma_channel_tx = -1;
-	}
 	return 0;
 }
 
@@ -1060,7 +1034,6 @@ static int mxs_auart_probe(struct platform_device *pdev)
 	u32 version;
 	int ret = 0;
 	struct resource *r;
-	struct pinctrl *pinctrl;
 
 	s = kzalloc(sizeof(struct mxs_auart_port), GFP_KERNEL);
 	if (!s) {
@@ -1074,12 +1047,6 @@ static int mxs_auart_probe(struct platform_device *pdev)
 	else if (ret < 0)
 		goto out_free;
 
-	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
-	if (IS_ERR(pinctrl)) {
-		ret = PTR_ERR(pinctrl);
-		goto out_free;
-	}
-
 	if (of_id) {
 		pdev->id_entry = of_id->data;
 		s->devtype = pdev->id_entry->driver_data;
@@ -1101,10 +1068,10 @@ static int mxs_auart_probe(struct platform_device *pdev)
 	s->port.membase = ioremap(r->start, resource_size(r));
 	s->port.ops = &mxs_auart_ops;
 	s->port.iotype = UPIO_MEM;
-	s->port.fifosize = 16;
+	s->port.fifosize = MXS_AUART_FIFO_SIZE;
 	s->port.uartclk = clk_get_rate(s->clk);
 	s->port.type = PORT_IMX;
-	s->port.dev = s->dev = get_device(&pdev->dev);
+	s->port.dev = s->dev = &pdev->dev;
 
 	s->ctrl = 0;
 
@@ -1135,7 +1102,6 @@ out_free_irq:
 	auart_port[pdev->id] = NULL;
 	free_irq(s->irq, s);
 out_free_clk:
-	put_device(s->dev);
 	clk_put(s->clk);
 out_free:
 	kfree(s);
@@ -1151,7 +1117,6 @@ static int mxs_auart_remove(struct platform_device *pdev)
 
 	auart_port[pdev->id] = NULL;
 
-	put_device(s->dev);
 	clk_put(s->clk);
 	free_irq(s->irq, s);
 	kfree(s);