From: Martin Aberg <mab...@gaisler.com>
Utilize the APBUART RX delayed interrupt if available. It also
enables RX FIFO interrupt when used.
The APBUART RX delayed interrupt is supported by the GR740.
---
c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c | 44 +++++++++++++++++++++--
1 file changed, 42 insertions(+), 2 deletions(-)
diff --git a/c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c
b/c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c
index b070db5..fedcf07 100644
--- a/c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c
+++ b/c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c
@@ -50,6 +50,11 @@ extern void apbuart_outbyte_polled(
extern int apbuart_inbyte_nonblocking(struct apbuart_regs *regs);
extern struct apbuart_regs *dbg_uart; /* The debug UART */
+/* Probed hardware capabilities */
+enum {
+ CAP_FIFO = 0x01, /* FIFO available */
+ CAP_DI = 0x02, /* RX delayed interrupt available */
+};
struct apbuart_priv {
struct console_dev condev;
struct drvmgr_dev *dev;
@@ -58,6 +63,7 @@ struct apbuart_priv {
char devName[32];
volatile int sending;
int mode;
+ int cap;
};
/* Getters for different interfaces. It happens to be just casting which we do
@@ -186,6 +192,30 @@ static const rtems_termios_device_handler handler_polled =
{
.mode = TERMIOS_POLLED
};
+/*
+ * APBUART hardware instantiation is flexible. Probe features here and driver
+ * can select appropriate routines for the hardware. probecap() return value
+ * is a CAP_ bitmask.
+ */
+static int probecap(struct apbuart_regs *regs)
+{
+ int cap = 0;
+
+ /* Probe FIFO */
+ if (regs->ctrl & APBUART_CTRL_FA) {
+ cap |= CAP_FIFO;
+
+ /* Probe RX delayed interrupt */
+ regs->ctrl |= APBUART_CTRL_DI;
+ if (regs->ctrl & APBUART_CTRL_DI) {
+ regs->ctrl &= ~APBUART_CTRL_DI;
+ cap |= CAP_DI;
+ }
+ }
+
+ return cap;
+}
+
int apbuart_init1(struct drvmgr_dev *dev)
{
struct apbuart_priv *priv;
@@ -254,6 +284,8 @@ int apbuart_init1(struct drvmgr_dev *dev)
priv->regs->ctrl = db;
+ priv->cap = probecap(priv->regs);
+
/* The system console and Debug console may depend on this device, so
* initialize it straight away.
*
@@ -417,6 +449,7 @@ static bool first_open(
if (uart->mode != TERMIOS_POLLED) {
int ret;
+ uint32_t ctrl;
/* Register interrupt and enable it */
ret = drvmgr_interrupt_register(
@@ -427,8 +460,15 @@ static bool first_open(
}
uart->sending = 0;
+
/* Turn on RX interrupts */
- uart->regs->ctrl |= APBUART_CTRL_RI;
+ ctrl = uart->regs->ctrl;
+ ctrl |= APBUART_CTRL_RI;
+ if (uart->cap & CAP_DI) {
+ /* Use RX FIFO interrupt only if delayed interrupt
available. */
+ ctrl |= (APBUART_CTRL_DI | APBUART_CTRL_RF);
+ }
+ uart->regs->ctrl = ctrl;
}
return true;
@@ -446,7 +486,7 @@ static void last_close(
if (uart->mode != TERMIOS_POLLED) {
/* Turn off RX interrupts */
rtems_termios_device_lock_acquire(base, &lock_context);
- uart->regs->ctrl &= ~(APBUART_CTRL_RI);
+ uart->regs->ctrl &= ~(APBUART_CTRL_RI | APBUART_CTRL_RF);
rtems_termios_device_lock_release(base, &lock_context);
/**** Flush device ****/
--
2.7.4
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