[PATCH 1/4] serial: 8250_dw: Add support for big-endian MMIO accesses

[Noam Camus <noamc@xxxxxxxxxx>]

From: Noam Camus <noamc@xxxxxxxxxx>

Add support for UPIO_MEM32BE in addition to UPIO_MEM32.

Signed-off-by: Noam Camus <noamc@xxxxxxxxxx>
---
 drivers/tty/serial/8250/8250_dw.c |   42 ++++++++++++++++++++++++++++++------
 1 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 176f18f..d12b674 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -173,15 +173,13 @@ static void dw8250_serial_outq(struct uart_port *p, int offset, int value)
 }
 #endif /* CONFIG_64BIT */
 
-static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
+static void dw8250_check_control(struct uart_port *p, int offset, int value)
 {
 	struct dw8250_data *d = p->private_data;
 
 	if (offset == UART_MCR)
 		d->last_mcr = value;
 
-	writel(value, p->membase + (offset << p->regshift));
-
 	/* Make sure LCR write wasn't ignored */
 	if (offset == UART_LCR) {
 		int tries = 1000;
@@ -190,7 +188,12 @@ static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
 			if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
 				return;
 			dw8250_force_idle(p);
-			writel(value, p->membase + (UART_LCR << p->regshift));
+			if (p->iotype == UPIO_MEM32BE)
+				iowrite32be(value,
+					p->membase + (UART_LCR << p->regshift));
+			else
+				writel(value,
+					p->membase + (UART_LCR << p->regshift));
 		}
 		/*
 		 * FIXME: this deadlocks if port->lock is already held
@@ -199,6 +202,12 @@ static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
 	}
 }
 
+static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
+{
+	writel(value, p->membase + (offset << p->regshift));
+	dw8250_check_control(p, offset, value);
+}
+
 static unsigned int dw8250_serial_in32(struct uart_port *p, int offset)
 {
 	unsigned int value = readl(p->membase + (offset << p->regshift));
@@ -206,6 +215,19 @@ static unsigned int dw8250_serial_in32(struct uart_port *p, int offset)
 	return dw8250_modify_msr(p, offset, value);
 }
 
+static void dw8250_serial_out32be(struct uart_port *p, int offset, int value)
+{
+	iowrite32be(value, p->membase + (offset << p->regshift));
+	dw8250_check_control(p, offset, value);
+}
+
+static unsigned int dw8250_serial_in32be(struct uart_port *p, int offset)
+{
+	unsigned int value = ioread32be(p->membase + (offset << p->regshift));
+
+	return dw8250_modify_msr(p, offset, value);
+}
+
 static int dw8250_handle_irq(struct uart_port *p)
 {
 	struct dw8250_data *d = p->private_data;
@@ -322,9 +344,15 @@ static int dw8250_probe_of(struct uart_port *p,
 		case 1:
 			break;
 		case 4:
-			p->iotype = UPIO_MEM32;
-			p->serial_in = dw8250_serial_in32;
-			p->serial_out = dw8250_serial_out32;
+			p->iotype = of_device_is_big_endian(np) ?
+				    UPIO_MEM32BE : UPIO_MEM32;
+			if (p->iotype == UPIO_MEM32) {
+				p->serial_in = dw8250_serial_in32;
+				p->serial_out = dw8250_serial_out32;
+			} else {
+				p->serial_in = dw8250_serial_in32be;
+				p->serial_out = dw8250_serial_out32be;
+			}
 			break;
 		default:
 			dev_err(p->dev, "unsupported reg-io-width (%u)\n", val);
-- 
1.7.1

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