[v11,4/5] uart: pl011: Improve LCRH register access decision

Message ID 1435050149-21153-5-git-send-email-jun.nie@linaro.org
State New
Headers show

Commit Message

Jun Nie June 23, 2015, 9:02 a.m.
Improve LCRH register access decision as ARM PL011 lcrh
register serve as both TX and RX, while other SOC may
implement TX and RX function with separated register.

Signed-off-by: Jun Nie <jun.nie@linaro.org>
---
 drivers/tty/serial/amba-pl011.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

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diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 5795b18..5e92d57 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -235,6 +235,11 @@  struct uart_amba_port {
 #endif
 };
 
+static bool is_implemented(struct uart_amba_port *uap, unsigned int reg)
+{
+	return uap->reg_lut[reg] != (u16)~0;
+}
+
 static unsigned int pl011_readw(struct uart_amba_port *uap, int index)
 {
 	WARN_ON(index > REG_NR);
@@ -1684,7 +1689,7 @@  static int pl011_hwinit(struct uart_port *port)
 static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h)
 {
 	pl011_writew(uap, lcr_h, uap->lcrh_rx);
-	if (uap->lcrh_rx != uap->lcrh_tx) {
+	if (is_implemented(uap, REG_ST_LCRH_RX)) {
 		int i;
 		/*
 		 * Wait 10 PCLKs before writing LCRH_TX register,
@@ -1812,7 +1817,7 @@  static void pl011_shutdown(struct uart_port *port)
 	 * disable break condition and fifos
 	 */
 	pl011_shutdown_channel(uap, uap->lcrh_rx);
-	if (uap->lcrh_rx != uap->lcrh_tx)
+	if (is_implemented(uap, REG_ST_LCRH_RX))
 		pl011_shutdown_channel(uap, uap->lcrh_tx);
 
 	/*