[PATCH v4 1/2] modify pl011 driver to let it work as wakeup source

[PATCH v4 1/2] modify pl011 driver to let it work as wakeup source

[Zhaoyang Huang]

the commit use the latest dev_pm_set_wake_irq API instead
of the enable_irq_wake and IRQF_NO_SUSPEND to configure the
ttyAMA device to work as the wakeup source

Signed-off-by: Zhaoyang Huang <zhaoyang.huang@linaro.org>
---
 drivers/tty/serial/amba-pl011.c |   47 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 46 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index fd27e98..1923b94 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -59,6 +59,11 @@
 #include <linux/sizes.h>
 #include <linux/io.h>
 #include <linux/acpi.h>
+#include <linux/suspend.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/irq.h>
+
+static struct device *uart_dev;
 
 #define UART_NR			14
 
@@ -2353,11 +2358,29 @@ static int pl011_register_port(struct uart_amba_port *uap)
 	return ret;
 }
 
+struct uart_match {
+	struct uart_port *port;
+	struct uart_driver *driver;
+};
+
+static int match_uart_port(struct device *dev, void *data)
+{
+	struct uart_match *match = data;
+
+	dev_t devt = MKDEV(match->driver->major, match->driver->minor) +
+		match->port->line;
+
+	pr_info("the match data of ttyAMA0 is %d %d\n",
+			(int)devt, (int)dev->devt);
+
+	return dev->devt == devt; /* Actually, only one tty per port */
+}
 static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 {
 	struct uart_amba_port *uap;
 	struct vendor_data *vendor = id->data;
 	int portnr, ret;
+	struct uart_match match;
 
 	portnr = pl011_find_free_port();
 	if (portnr < 0)
@@ -2387,13 +2410,35 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 
 	amba_set_drvdata(dev, uap);
 
-	return pl011_register_port(uap);
+	ret = pl011_register_port(uap);
+
+	if (!of_find_property(dev->dev.of_node, "linux,wakeup", NULL)) {
+		uart_dev = NULL;
+		return ret;
+	}
+
+	match.port = &uap->port;
+	match.driver = &amba_reg;
+
+	uart_dev = device_find_child(&dev->dev, &match, match_uart_port);
+
+	if (uart_dev) {
+		device_init_wakeup(uart_dev, true);
+		dev_pm_set_wake_irq(uart_dev, uap->port.irq);
+	}
+
+	return ret;
 }
 
 static int pl011_remove(struct amba_device *dev)
 {
 	struct uart_amba_port *uap = amba_get_drvdata(dev);
 
+	if (uart_dev) {
+		dev_pm_clear_wake_irq(uart_dev);
+		device_init_wakeup(uart_dev, false);
+	}
+
 	uart_remove_one_port(&amba_reg, &uap->port);
 	pl011_unregister_port(uap);
 	return 0;
-- 
1.7.9.5

[PATCH v4 2/2] add property of "linux,wakeup" for juno.dts

[Zhaoyang Huang]

add property of "linux,wakeup" to let the driver know
if the device should work as wakeup source

Signed-off-by: Zhaoyang Huang <zhaoyang.huang@linaro.org>
---
 Documentation/devicetree/bindings/serial/pl011.txt |    3 ++-
 arch/arm64/boot/dts/arm/juno-base.dtsi             |    1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/serial/pl011.txt b/Documentation/devicetree/bindings/serial/pl011.txt
index cbae3d9..609e8e9 100644
--- a/Documentation/devicetree/bindings/serial/pl011.txt
+++ b/Documentation/devicetree/bindings/serial/pl011.txt
@@ -35,7 +35,8 @@ Optional properties:
 - poll-timeout-ms:
 	   Poll timeout when auto-poll is set, default
 	   3000ms.
-
+- linux,wakeup:
+	   set the pl011 work as wakeup source for suspend to ram/idle
 See also bindings/arm/primecell.txt
 
 Example:
diff --git a/arch/arm64/boot/dts/arm/juno-base.dtsi b/arch/arm64/boot/dts/arm/juno-base.dtsi
index a3d5a77..f7bb150 100644
--- a/arch/arm64/boot/dts/arm/juno-base.dtsi
+++ b/arch/arm64/boot/dts/arm/juno-base.dtsi
@@ -152,6 +152,7 @@
 		interrupts = <GIC_SPI 83 IRQ_TYPE_LEVEL_HIGH>;
 		clocks = <&soc_uartclk>, <&soc_refclk100mhz>;
 		clock-names = "uartclk", "apb_pclk";
+		linux,wakeup;
 	};
 
 	i2c@7ffa0000 {
-- 
1.7.9.5

Re: [PATCH v4 2/2] add property of "linux,wakeup" for juno.dts

[Sudeep Holla]

On 16/09/15 07:47, Zhaoyang Huang wrote:
> add property of "linux,wakeup" to let the driver know
> if the device should work as wakeup source
>

I think I made it *pretty clear multiple times by now* that PL011 is
*not a wakeup source* on Juno. I have no idea what you are testing, it
simply can't wakeup the system for suspended state. So I seriously doubt
now what is that you are testing.

So, this patch clearly gets NACK.

Regards,
Sudeep

Re: [PATCH v4 2/2] add property of "linux,wakeup" for juno.dts

[Sudeep Holla]

Hi Zhaouyang,

On 16/09/15 09:53, Zhaoyang Huang wrote:
> Hi Sudeep,

Please stop top-posting, I have told you many times now in private.

> Sorry for the confusions I made. I am testing the suspend to idle on
> juno, which is similar to suspend to ram, while the difference is the
> cpu will go into idle itself(you can refer the function freeze_enter())
> instead of running cpu_suspend finally. I find that the pl011 can wakeup
> the system by receiving from the tty.
>

No, it shouldn't be allowed to be configured as wakeup if it can't
wakeup from S2R. So please stop sending this patch. I need to see real
use case for PL011 as a wakeup source.

Also, if we go by your definition, we can make any interrupt as wakeup
source. You need to understand that we hardware support for an interrupt
to be a wakeup irq.

Regards,
Sudeep