[2/2] serial: mps2-uart: support combined tx and rx irq

Commit Message

Vladimir Murzin Jan. 25, 2019, 2:13 p.m. UTC

It turns out that some designs went for implementing only combined tx
and rx interrupt, which is currently not supported by the driver.
Support of combined irq is built on top of existent irq handlers and
activated by the hint form device tree.

Signed-off-by: Vladimir Murzin <[e-mail]>
---
 drivers/tty/serial/mps2-uart.c | 89 ++++++++++++++++++++++++++++++------------
 1 file changed, 64 insertions(+), 25 deletions(-)

Comments

Vladimir Murzin Jan. 30, 2019, 9 a.m. UTC | #1

On 1/25/19 2:13 PM, Vladimir Murzin wrote:
> It turns out that some designs went for implementing only combined tx
> and rx interrupt, which is currently not supported by the driver.
> Support of combined irq is built on top of existent irq handlers and
> activated by the hint form device tree.
> 

It seems that folks combine rx, tx and overrun interrupts, so I'll send v2

Cheers
Vladimir

Patch

diff --git a/drivers/tty/serial/mps2-uart.c b/drivers/tty/serial/mps2-uart.c
index 6da0633..e5fe764 100644
--- a/drivers/tty/serial/mps2-uart.c
+++ b/drivers/tty/serial/mps2-uart.c
@@ -66,11 +66,17 @@ 
 
 #define MPS2_MAX_PORTS		3
 
+#define UART_PORT_COMBINED_IRQS	BIT(0)
+
 struct mps2_uart_port {
 	struct uart_port port;
 	struct clk *clk;
-	unsigned int tx_irq;
+	union {
+		unsigned int combined_irq;
+		unsigned int tx_irq;
+	};
 	unsigned int rx_irq;
+	unsigned int flags;
 };
 
 static inline struct mps2_uart_port *to_mps2_port(struct uart_port *port)
@@ -232,6 +238,17 @@  static irqreturn_t mps2_uart_txirq(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t mps2_uart_combinedirq(int irq, void *data)
+{
+	if (mps2_uart_rxirq(irq, data) == IRQ_HANDLED)
+		return IRQ_HANDLED;
+
+	if (mps2_uart_txirq(irq, data) == IRQ_HANDLED)
+		return IRQ_HANDLED;
+
+	return IRQ_NONE;
+}
+
 static irqreturn_t mps2_uart_oerrirq(int irq, void *data)
 {
 	irqreturn_t handled = IRQ_NONE;
@@ -275,26 +292,35 @@  static int mps2_uart_startup(struct uart_port *port)
 
 	mps2_uart_write8(port, control, UARTn_CTRL);
 
-	ret = request_irq(mps_port->rx_irq, mps2_uart_rxirq, 0,
-			  MAKE_NAME(-rx), mps_port);
-	if (ret) {
-		dev_err(port->dev, "failed to register rxirq (%d)\n", ret);
-		return ret;
-	}
-
-	ret = request_irq(mps_port->tx_irq, mps2_uart_txirq, 0,
-			  MAKE_NAME(-tx), mps_port);
-	if (ret) {
-		dev_err(port->dev, "failed to register txirq (%d)\n", ret);
-		goto err_free_rxirq;
-	}
-
 	ret = request_irq(port->irq, mps2_uart_oerrirq, IRQF_SHARED,
 			  MAKE_NAME(-overrun), mps_port);
 
 	if (ret) {
 		dev_err(port->dev, "failed to register oerrirq (%d)\n", ret);
-		goto err_free_txirq;
+		return ret;
+	}
+
+	if (mps_port->flags & UART_PORT_COMBINED_IRQS) {
+		ret = request_irq(mps_port->combined_irq, mps2_uart_combinedirq, 0,
+				  MAKE_NAME(-combined), mps_port);
+		if (ret) {
+			dev_err(port->dev, "failed to register combinedirq (%d)\n", ret);
+			goto err_free_oerrirq;
+		}
+	} else {
+		ret = request_irq(mps_port->rx_irq, mps2_uart_rxirq, 0,
+			  MAKE_NAME(-rx), mps_port);
+		if (ret) {
+			dev_err(port->dev, "failed to register rxirq (%d)\n", ret);
+			goto err_free_oerrirq;
+		}
+
+		ret = request_irq(mps_port->tx_irq, mps2_uart_txirq, 0,
+			  MAKE_NAME(-tx), mps_port);
+		if (ret) {
+			dev_err(port->dev, "failed to register txirq (%d)\n", ret);
+			goto err_free_rxirq;
+		}
 	}
 
 	control |= UARTn_CTRL_RX_GRP | UARTn_CTRL_TX_GRP;
@@ -303,10 +329,10 @@  static int mps2_uart_startup(struct uart_port *port)
 
 	return 0;
 
-err_free_txirq:
-	free_irq(mps_port->tx_irq, mps_port);
 err_free_rxirq:
 	free_irq(mps_port->rx_irq, mps_port);
+err_free_oerrirq:
+	free_irq(port->irq, mps_port);
 
 	return ret;
 }
@@ -320,8 +346,13 @@  static void mps2_uart_shutdown(struct uart_port *port)
 
 	mps2_uart_write8(port, control, UARTn_CTRL);
 
-	free_irq(mps_port->rx_irq, mps_port);
-	free_irq(mps_port->tx_irq, mps_port);
+	if (mps_port->flags & UART_PORT_COMBINED_IRQS) {
+		free_irq(mps_port->combined_irq, mps_port);
+	} else {
+		free_irq(mps_port->rx_irq, mps_port);
+		free_irq(mps_port->tx_irq, mps_port);
+	}
+
 	free_irq(port->irq, mps_port);
 }
 
@@ -511,6 +542,9 @@  static int mps2_of_get_port(struct platform_device *pdev,
 	if (id < 0)
 		return id;
 
+	if (of_property_read_bool(np, "arm,mps2-combined-irq-only"))
+		mps_port->flags |= UART_PORT_COMBINED_IRQS;
+
 	mps_port->port.line = id;
 
 	return 0;
@@ -529,11 +563,6 @@  static int mps2_init_port(struct platform_device *pdev,
 
 	mps_port->port.mapbase = res->start;
 	mps_port->port.mapsize = resource_size(res);
-
-	mps_port->rx_irq = platform_get_irq(pdev, 0);
-	mps_port->tx_irq = platform_get_irq(pdev, 1);
-	mps_port->port.irq = platform_get_irq(pdev, 2);
-
 	mps_port->port.iotype = UPIO_MEM;
 	mps_port->port.flags = UPF_BOOT_AUTOCONF;
 	mps_port->port.fifosize = 1;
@@ -552,6 +581,16 @@  static int mps2_init_port(struct platform_device *pdev,
 
 	clk_disable_unprepare(mps_port->clk);
 
+
+	if (mps_port->flags & UART_PORT_COMBINED_IRQS) {
+		mps_port->combined_irq = platform_get_irq(pdev, 0);
+		mps_port->port.irq = platform_get_irq(pdev, 1);
+	} else {
+		mps_port->rx_irq = platform_get_irq(pdev, 0);
+		mps_port->tx_irq = platform_get_irq(pdev, 1);
+		mps_port->port.irq = platform_get_irq(pdev, 2);
+	}
+
 	return ret;
 }