Re: [PATCH v3 03/22] usb: ulpi: Support device discovery via device properties
From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Date: 2016-09-02 14:10:56
Also in:
linux-arm-kernel, linux-arm-msm, lkml
Subsystem:
the rest, ulpi bus, usb subsystem · Maintainers:
Linus Torvalds, Heikki Krogerus, Greg Kroah-Hartman
Hi, On Wed, Aug 31, 2016 at 05:40:17PM -0700, Stephen Boyd wrote:
quoted hunk ↗ jump to hunk
@@ -174,14 +219,37 @@ static int ulpi_register(struct device *dev, struct ulpi *ulpi) ulpi->id.product = ulpi_read(ulpi, ULPI_PRODUCT_ID_LOW); ulpi->id.product |= ulpi_read(ulpi, ULPI_PRODUCT_ID_HIGH) << 8; + return 0; +} + +static int ulpi_register(struct device *dev, struct ulpi *ulpi) +{ + int ret; + ulpi->dev.parent = dev; ulpi->dev.bus = &ulpi_bus; ulpi->dev.type = &ulpi_dev_type; dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev)); + if (IS_ENABLED(CONFIG_OF)) {
I don't think you need to check that in this case.
+ ret = ulpi_of_register(ulpi); + if (ret) + return ret; + } + ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev));
ACPI_COMPANION_SET will overwrite the primary fwnode unconditionally, so just to play it safe, do this before you call ulpi_of_register().
- request_module("ulpi:v%04xp%04x", ulpi->id.vendor, ulpi->id.product);
+ ret = ulpi_read_id(ulpi);
+ /*
+ * Ignore failure in case of DT node because the device may
+ * not be powered up yet but we can still match by compatible
+ */
+ if (ret && !ulpi->dev.of_node)
+ return ret;
+
+ if (of_device_request_module(&ulpi->dev))
+ request_module("ulpi:v%04xp%04x", ulpi->id.vendor,
+ ulpi->id.product);I don't think this works in all cases. If of_device_request_module() fails and we don't have the id.vendor/product set, we should not register the device. It also looks a bit messy. How about just using of_device_request_module() call as fallback in ulpi_read_id() and moving also request_module() call there:
diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
index 30ea770..667246c 100644
--- a/drivers/usb/common/ulpi.c
+++ b/drivers/usb/common/ulpi.c@@ -205,14 +205,14 @@ static int ulpi_read_id(struct ulpi *ulpi) /* Test the interface */ ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa); if (ret < 0) - return ret; + goto err; ret = ulpi_read(ulpi, ULPI_SCRATCH); if (ret < 0) - return ret; + goto err; if (ret != 0xaa) - return -ENODEV; + goto err; ulpi->id.vendor = ulpi_read(ulpi, ULPI_VENDOR_ID_LOW); ulpi->id.vendor |= ulpi_read(ulpi, ULPI_VENDOR_ID_HIGH) << 8;
@@ -220,7 +220,11 @@ static int ulpi_read_id(struct ulpi *ulpi) ulpi->id.product = ulpi_read(ulpi, ULPI_PRODUCT_ID_LOW); ulpi->id.product |= ulpi_read(ulpi, ULPI_PRODUCT_ID_HIGH) << 8; + request_module("ulpi:v%04xp%04x", ulpi->id.vendor, ulpi->id.product); + return 0; +err: + return of_device_request_module(&ulpi->dev); } static int ulpi_register(struct device *dev, struct ulpi *ulpi)
@@ -232,25 +236,15 @@ static int ulpi_register(struct device *dev, struct ulpi *ulpi) ulpi->dev.type = &ulpi_dev_type; dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev)); - if (IS_ENABLED(CONFIG_OF)) { - ret = ulpi_of_register(ulpi); - if (ret) - return ret; - } - ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev)); - ret = ulpi_read_id(ulpi); - /* - * Ignore failure in case of DT node because the device may - * not be powered up yet but we can still match by compatible - */ - if (ret && !ulpi->dev.of_node) + ret = ulpi_of_register(ulpi); + if (ret) return ret; - if (of_device_request_module(&ulpi->dev)) - request_module("ulpi:v%04xp%04x", ulpi->id.vendor, - ulpi->id.product); + ret = ulpi_read_id(ulpi); + if (ret) + return ret; ret = device_register(&ulpi->dev); if (ret)
Cheers, -- heikki