Re: [PATCH v5 03/23] usb: ulpi: Support device discovery via DT

[Heikki Krogerus]

On Mon, Oct 17, 2016 at 06:56:16PM -0700, Stephen Boyd wrote:
> The qcom HSIC ULPI phy doesn't have any bits set in the vendor or
> product ID registers. This makes it impossible to make a ULPI
> driver match against the ID registers. Add support to discover
> the ULPI phys via DT help alleviate this problem. In the DT case,
> we'll look for a ULPI bus node underneath the device registering
> the ULPI viewport (or the parent of that device to support
> chipidea's device layout) and then match up the phy node
> underneath that with the ULPI device that's created.
> 
> The side benefit of this is that we can use standard properties
> in the phy node like clks, regulators, gpios, etc. because we
> don't have firmware like ACPI to turn these things on for us. And
> we can use the DT phy binding to point our phy consumer to the
> phy provider.
> 
> The ULPI bus code supports native enumeration by reading the
> vendor ID and product ID registers at device creation time, but
> we can't be certain that those register reads will succeed if the
> phy is not powered up. To avoid any problems with reading the ID
> registers before the phy is powered we fallback to DT matching
> when the ID reads fail.
> 
> If the ULPI spec had some generic power sequencing for these
> registers we could put that into the ULPI bus layer and power up
> the device before reading the ID registers. Unfortunately this
> doesn't exist and the power sequence is usually device specific.
> By having the device matched up with DT we can avoid this
> problem.
> 
> Cc: Greg Kroah-Hartman 
> Cc: Heikki Krogerus 
> Cc: 
> Cc: Rob Herring 
> Signed-off-by: Stephen Boyd 

Acked-by: Heikki Krogerus 

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Re: [PATCH v5 03/23] usb: ulpi: Support device discovery via DT

[Rob Herring]

On Mon, Oct 17, 2016 at 06:56:16PM -0700, Stephen Boyd wrote:
> The qcom HSIC ULPI phy doesn't have any bits set in the vendor or
> product ID registers. This makes it impossible to make a ULPI
> driver match against the ID registers. Add support to discover
> the ULPI phys via DT help alleviate this problem. In the DT case,
> we'll look for a ULPI bus node underneath the device registering
> the ULPI viewport (or the parent of that device to support
> chipidea's device layout) and then match up the phy node
> underneath that with the ULPI device that's created.
> 
> The side benefit of this is that we can use standard properties
> in the phy node like clks, regulators, gpios, etc. because we
> don't have firmware like ACPI to turn these things on for us. And
> we can use the DT phy binding to point our phy consumer to the
> phy provider.
> 
> The ULPI bus code supports native enumeration by reading the
> vendor ID and product ID registers at device creation time, but
> we can't be certain that those register reads will succeed if the
> phy is not powered up. To avoid any problems with reading the ID
> registers before the phy is powered we fallback to DT matching
> when the ID reads fail.
> 
> If the ULPI spec had some generic power sequencing for these
> registers we could put that into the ULPI bus layer and power up
> the device before reading the ID registers. Unfortunately this
> doesn't exist and the power sequence is usually device specific.
> By having the device matched up with DT we can avoid this
> problem.
> 
> Cc: Greg Kroah-Hartman 
> Cc: Heikki Krogerus 
> Cc: 
> Cc: Rob Herring 
> Signed-off-by: Stephen Boyd 
> ---
>  Documentation/devicetree/bindings/usb/ulpi.txt | 20 +++
>  drivers/usb/common/ulpi.c  | 79 
> --
>  2 files changed, 93 insertions(+), 6 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/usb/ulpi.txt

Acked-by: Rob Herring 
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[PATCH v5 03/23] usb: ulpi: Support device discovery via DT

[Stephen Boyd]

The qcom HSIC ULPI phy doesn't have any bits set in the vendor or
product ID registers. This makes it impossible to make a ULPI
driver match against the ID registers. Add support to discover
the ULPI phys via DT help alleviate this problem. In the DT case,
we'll look for a ULPI bus node underneath the device registering
the ULPI viewport (or the parent of that device to support
chipidea's device layout) and then match up the phy node
underneath that with the ULPI device that's created.

The side benefit of this is that we can use standard properties
in the phy node like clks, regulators, gpios, etc. because we
don't have firmware like ACPI to turn these things on for us. And
we can use the DT phy binding to point our phy consumer to the
phy provider.

The ULPI bus code supports native enumeration by reading the
vendor ID and product ID registers at device creation time, but
we can't be certain that those register reads will succeed if the
phy is not powered up. To avoid any problems with reading the ID
registers before the phy is powered we fallback to DT matching
when the ID reads fail.

If the ULPI spec had some generic power sequencing for these
registers we could put that into the ULPI bus layer and power up
the device before reading the ID registers. Unfortunately this
doesn't exist and the power sequence is usually device specific.
By having the device matched up with DT we can avoid this
problem.

Cc: Greg Kroah-Hartman 
Cc: Heikki Krogerus 
Cc: 
Cc: Rob Herring 
Signed-off-by: Stephen Boyd 
---
 Documentation/devicetree/bindings/usb/ulpi.txt | 20 +++
 drivers/usb/common/ulpi.c  | 79 --
 2 files changed, 93 insertions(+), 6 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/usb/ulpi.txt

diff --git a/Documentation/devicetree/bindings/usb/ulpi.txt 
b/Documentation/devicetree/bindings/usb/ulpi.txt
new file mode 100644
index ..ca179dc4bd50
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/ulpi.txt
@@ -0,0 +1,20 @@
+ULPI bus binding
+
+
+Phys that are behind a ULPI connection can be described with the following
+binding. The host controller shall have a "ulpi" named node as a child, and
+that node shall have one enabled node underneath it representing the ulpi
+device on the bus.
+
+EXAMPLE
+---
+
+usb {
+   compatible = "vendor,usb-controller";
+
+   ulpi {
+   phy {
+   compatible = "vendor,phy";
+   };
+   };
+};
diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
index 8b317702d761..c9480d77810c 100644
--- a/drivers/usb/common/ulpi.c
+++ b/drivers/usb/common/ulpi.c
@@ -16,6 +16,9 @@
 #include 
 #include 
 #include 
+#include 
+#include 
+#include 
 
 /* -- 
*/
 
@@ -39,6 +42,10 @@ static int ulpi_match(struct device *dev, struct 
device_driver *driver)
struct ulpi *ulpi = to_ulpi_dev(dev);
const struct ulpi_device_id *id;
 
+   /* Some ULPI devices don't have a vendor id so rely on OF match */
+   if (ulpi->id.vendor == 0)
+   return of_driver_match_device(dev, driver);
+
for (id = drv->id_table; id->vendor; id++)
if (id->vendor == ulpi->id.vendor &&
id->product == ulpi->id.product)
@@ -50,6 +57,11 @@ static int ulpi_match(struct device *dev, struct 
device_driver *driver)
 static int ulpi_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
struct ulpi *ulpi = to_ulpi_dev(dev);
+   int ret;
+
+   ret = of_device_uevent_modalias(dev, env);
+   if (ret != -ENODEV)
+   return ret;
 
if (add_uevent_var(env, "MODALIAS=ulpi:v%04xp%04x",
   ulpi->id.vendor, ulpi->id.product))
@@ -60,6 +72,11 @@ static int ulpi_uevent(struct device *dev, struct 
kobj_uevent_env *env)
 static int ulpi_probe(struct device *dev)
 {
struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
+   int ret;
+
+   ret = of_clk_set_defaults(dev->of_node, false);
+   if (ret < 0)
+   return ret;
 
return drv->probe(to_ulpi_dev(dev));
 }
@@ -87,8 +104,13 @@ static struct bus_type ulpi_bus = {
 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 char *buf)
 {
+   int len;
struct ulpi *ulpi = to_ulpi_dev(dev);
 
+   len = of_device_get_modalias(dev, buf, PAGE_SIZE - 1);
+   if (len != -ENODEV)
+   return len;
+
return sprintf(buf, "ulpi:v%04xp%04x\n",
   ulpi->id.vendor, ulpi->id.product);
 }
@@ -153,23 +175,45 @@ EXPORT_SYMBOL_GPL(ulpi_unregister_driver);
 
 /* -- 
*/
 
-static int