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-rw-r--r--arch/arm/boot/dts/armada-38x.dtsi4
-rw-r--r--drivers/tty/serial/8250/8250_dw.c31
2 files changed, 29 insertions, 6 deletions
diff --git a/arch/arm/boot/dts/armada-38x.dtsi b/arch/arm/boot/dts/armada-38x.dtsi
index 4cc09e43eea2..6916d7532ad2 100644
--- a/arch/arm/boot/dts/armada-38x.dtsi
+++ b/arch/arm/boot/dts/armada-38x.dtsi
@@ -163,7 +163,7 @@
};
uart0: serial@12000 {
- compatible = "snps,dw-apb-uart";
+ compatible = "marvell,armada-38x-uart";
reg = <0x12000 0x100>;
reg-shift = <2>;
interrupts = <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>;
@@ -173,7 +173,7 @@
};
uart1: serial@12100 {
- compatible = "snps,dw-apb-uart";
+ compatible = "marvell,armada-38x-uart";
reg = <0x12100 0x100>;
reg-shift = <2>;
interrupts = <GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>;
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 6fcdb90f616a..0529b5cc094b 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -121,25 +121,44 @@ static void dw8250_check_lcr(struct uart_port *p, int value)
}
/* Returns once the transmitter is empty or we run out of retries */
-static void dw8250_tx_wait_empty(struct uart_port *p, int tries)
+static void dw8250_tx_wait_empty(struct uart_port *p)
{
+ unsigned int tries = 20000;
+ unsigned int delay_threshold = tries - 1000;
unsigned int lsr;
while (tries--) {
lsr = readb (p->membase + (UART_LSR << p->regshift));
if (lsr & UART_LSR_TEMT)
break;
- udelay (10);
+
+ /* The device is first given a chance to empty without delay,
+ * to avoid slowdowns at high bitrates. If after 1000 tries
+ * the buffer has still not emptied, allow more time for low-
+ * speed links. */
+ if (tries < delay_threshold)
+ udelay (1);
}
}
-static void dw8250_serial_out(struct uart_port *p, int offset, int value)
+static void dw8250_serial_out38x(struct uart_port *p, int offset, int value)
{
struct dw8250_data *d = p->private_data;
/* Allow the TX to drain before we reconfigure */
if (offset == UART_LCR)
- dw8250_tx_wait_empty(p, 1000);
+ dw8250_tx_wait_empty(p);
+
+ writeb(value, p->membase + (offset << p->regshift));
+
+ if (offset == UART_LCR && !d->uart_16550_compatible)
+ dw8250_check_lcr(p, value);
+}
+
+
+static void dw8250_serial_out(struct uart_port *p, int offset, int value)
+{
+ struct dw8250_data *d = p->private_data;
writeb(value, p->membase + (offset << p->regshift));
@@ -357,6 +376,9 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
p->serial_in = dw8250_serial_in32be;
p->serial_out = dw8250_serial_out32be;
}
+ if (of_device_is_compatible(np, "marvell,armada-38x-uart"))
+ p->serial_out = dw8250_serial_out38x;
+
} else if (acpi_dev_present("APMC0D08", NULL, -1)) {
p->iotype = UPIO_MEM32;
p->regshift = 2;
@@ -666,6 +688,7 @@ static const struct dev_pm_ops dw8250_pm_ops = {
static const struct of_device_id dw8250_of_match[] = {
{ .compatible = "snps,dw-apb-uart" },
{ .compatible = "cavium,octeon-3860-uart" },
+ { .compatible = "marvell,armada-38x-uart" },
{ /* Sentinel */ }
};
MODULE_DEVICE_TABLE(of, dw8250_of_match);