devicetree.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] ARM: dts: omap4-droid4: Fix occasional lost wakeirq for uart1
@ 2020-04-30 16:52 Tony Lindgren
  0 siblings, 0 replies; only message in thread
From: Tony Lindgren @ 2020-04-30 16:52 UTC (permalink / raw)
  To: linux-omap
  Cc: Benoît Cousson, devicetree, maemo-leste, Merlijn Wajer,
	Pavel Machek, Sebastian Reichel

Looks like using the UART CTS pin does not always trigger for a wake-up
when the SoC is idle.

This is probably because the modem first uses gpio_149 to signal the SoC
that data will be sent, and the CTS will only get used later when the
data transfer is starting.

Let's fix the issue by configuring the gpio_149 pad as the wakeirq for
UART. We have gpio_149 managed by the USB PHY for powering up the right
USB mode, and after that, the gpio gets recycled as the modem wake-up
pin. If needeed, the USB PHY can also later on be configured to use
gpio_149 pad as the wakeirq as a shared irq.

Let's also configure the missing properties for uart-has-rtscts and
current-speed for the modem port while at it. We already configure the
hardware flow control pins with uart1_pins pinctrl setting.

Cc: maemo-leste@lists.dyne.org
Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/boot/dts/motorola-mapphone-common.dtsi | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/arm/boot/dts/motorola-mapphone-common.dtsi b/arch/arm/boot/dts/motorola-mapphone-common.dtsi
--- a/arch/arm/boot/dts/motorola-mapphone-common.dtsi
+++ b/arch/arm/boot/dts/motorola-mapphone-common.dtsi
@@ -690,14 +690,18 @@ &timer9 {
 };
 
 /*
- * As uart1 is wired to mdm6600 with rts and cts, we can use the cts pin for
- * uart1 wakeirq.
+ * The uart1 port is wired to mdm6600 with rts and cts. The modem uses gpio_149
+ * for wake-up events for both the USB PHY and the UART. We can use gpio_149
+ * pad as the shared wakeirq for the UART rather than the RX or CTS pad as we
+ * have gpio_149 trigger before the UART transfer starts.
  */
 &uart1 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&uart1_pins>;
 	interrupts-extended = <&wakeupgen GIC_SPI 72 IRQ_TYPE_LEVEL_HIGH
-			       &omap4_pmx_core 0xfc>;
+			       &omap4_pmx_core 0x110>;
+	uart-has-rtscts;
+	current-speed = <115200>;
 };
 
 &uart3 {
-- 
2.26.2

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2020-04-30 16:52 UTC | newest]

Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2020-04-30 16:52 [PATCH] ARM: dts: omap4-droid4: Fix occasional lost wakeirq for uart1 Tony Lindgren

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).