diff mbox

[RFC,v2,11/13] usb: port: Parse pwrseq phandle from Device Tree

Message ID 1462451666-17945-12-git-send-email-k.kozlowski@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Krzysztof Kozlowski May 5, 2016, 12:34 p.m. UTC
Parse usb-pwrseq property from Device Tree to get the phandle to pwrseq
device. The pwrseq device will be used by USB hub to cycle the power
before activating ports.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
---
 drivers/usb/core/hub.h  |  3 +++
 drivers/usb/core/port.c | 15 +++++++++++++++
 2 files changed, 18 insertions(+)

Comments

Javier Martinez Canillas May 5, 2016, 8:10 p.m. UTC | #1
Hello Krzysztof,

On 05/05/2016 08:34 AM, Krzysztof Kozlowski wrote:
> Parse usb-pwrseq property from Device Tree to get the phandle to pwrseq
> device. The pwrseq device will be used by USB hub to cycle the power
> before activating ports.
> 
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> ---

[snip]

>  
> @@ -532,6 +534,14 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
>  		return retval;
>  	}
>  
> +	port_dev->dev.of_node = usb_of_get_child_node(hub->hdev->dev.of_node, port1);
> +	port_dev->pwrseq = pwrseq_alloc(&port_dev->dev);
> +	if (IS_ERR(port_dev->pwrseq)) {
> +		device_unregister(&port_dev->dev);
> +		/* TODO: what about EPROBE_DEFER? */

I think it's OK since the call chain is:

hub_probe()
       hub_configure()
              usb_hub_create_port_device()

so the hub_probe() will be deferred if the usb-pwrseq was not registered yet.
Unless I misunderstood your question :)

Anyway, patch looks good to me:

Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
 
Best regards,
Krzysztof Kozlowski May 6, 2016, 6:27 a.m. UTC | #2
On 05/05/2016 10:10 PM, Javier Martinez Canillas wrote:
> Hello Krzysztof,
> 
> On 05/05/2016 08:34 AM, Krzysztof Kozlowski wrote:
>> Parse usb-pwrseq property from Device Tree to get the phandle to pwrseq
>> device. The pwrseq device will be used by USB hub to cycle the power
>> before activating ports.
>>
>> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
>> ---
> 
> [snip]
> 
>>  
>> @@ -532,6 +534,14 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
>>  		return retval;
>>  	}
>>  
>> +	port_dev->dev.of_node = usb_of_get_child_node(hub->hdev->dev.of_node, port1);
>> +	port_dev->pwrseq = pwrseq_alloc(&port_dev->dev);
>> +	if (IS_ERR(port_dev->pwrseq)) {
>> +		device_unregister(&port_dev->dev);
>> +		/* TODO: what about EPROBE_DEFER? */
> 
> I think it's OK since the call chain is:
> 
> hub_probe()
>        hub_configure()
>               usb_hub_create_port_device()
> 
> so the hub_probe() will be deferred if the usb-pwrseq was not registered yet.
> Unless I misunderstood your question :)
> 
> Anyway, patch looks good to me:
> 
> Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>

Yes and deferred probing works in my case. That is an older comment
actually.

Thanks for review,
Krzysztof

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diff mbox

Patch

diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index 34c1a7e22aae..68ca89780d26 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -24,6 +24,8 @@ 
 #include <linux/usb/hcd.h>
 #include "usb.h"
 
+struct pwrseq;
+
 struct usb_hub {
 	struct device		*intfdev;	/* the "interface" device */
 	struct usb_device	*hdev;
@@ -101,6 +103,7 @@  struct usb_port {
 	struct usb_dev_state *port_owner;
 	struct usb_port *peer;
 	struct dev_pm_qos_request *req;
+	struct pwrseq *pwrseq;
 	enum usb_port_connect_type connect_type;
 	usb_port_location_t location;
 	struct mutex status_lock;
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 14718a9ffcfb..a875bd342452 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -18,6 +18,8 @@ 
 
 #include <linux/slab.h>
 #include <linux/pm_qos.h>
+#include <linux/pwrseq.h>
+#include <linux/usb/of.h>
 
 #include "hub.h"
 
@@ -532,6 +534,14 @@  int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 		return retval;
 	}
 
+	port_dev->dev.of_node = usb_of_get_child_node(hub->hdev->dev.of_node, port1);
+	port_dev->pwrseq = pwrseq_alloc(&port_dev->dev);
+	if (IS_ERR(port_dev->pwrseq)) {
+		device_unregister(&port_dev->dev);
+		/* TODO: what about EPROBE_DEFER? */
+		return PTR_ERR(port_dev->pwrseq);
+	}
+
 	find_and_link_peer(hub, port1);
 
 	/*
@@ -573,8 +583,13 @@  void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
 	struct usb_port *port_dev = hub->ports[port1 - 1];
 	struct usb_port *peer;
 
+	pwrseq_power_off(port_dev->pwrseq);
+
 	peer = port_dev->peer;
 	if (peer)
 		unlink_peers(port_dev, peer);
+
+	pwrseq_free(port_dev->pwrseq);
+	port_dev->pwrseq = NULL;
 	device_unregister(&port_dev->dev);
 }