[PATCH 02/21] usb: ulpi: Support device discovery via DT
From: Stephen Boyd <hidden>
Date: 2016-06-27 22:10:40
Also in:
linux-arm-msm, linux-devicetree
Quoting Heikki Krogerus (2016-06-27 07:34:22)
Hi, I'm fine with most of the patch, except.. On Sun, Jun 26, 2016 at 12:28:19AM -0700, Stephen Boyd wrote:quoted
@@ -39,7 +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; - for (id = drv->id_table; id->vendor; id++) + if (of_driver_match_device(dev, driver)) + return 1;I don't like this part. We should match separately like that only if the bus does not support native enumeration, and of course ULPI with its vendor and product IDs does. There really should always be IDs to match with here. So exceptions have to be solved before we attempt matching. Since we also have to support platforms where the PHY is initially powered off and reading the IDs from the registers is not possible because of that, I think we should consider getting the product and vendor IDs optionally from device properties. Something like this:
Ok, I'm a little worried about conflating the powered off problem with this product/vendor ID missing problem. But if you're ok with that I'll combine the two patches into one using your approach below.
quoted hunk ↗ jump to hunk
diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c index 01c0c04..6228a85 100644 --- a/drivers/usb/common/ulpi.c +++ b/drivers/usb/common/ulpi.c@@ -152,7 +152,7 @@ EXPORT_SYMBOL_GPL(ulpi_unregister_driver); /* -------------------------------------------------------------------------- */ -static int ulpi_register(struct device *dev, struct ulpi *ulpi) +static int ulpi_read_id(struct ulpi *ulpi) { int ret;@@ -174,6 +174,21 @@ 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; + + ret = device_property_read_u16(dev, "ulpi-vendor", &ulpi->id.vendor); + ret |= device_property_read_u16(dev, "ulpi-product", &ulpi->id.product); + if (ret) { + ret = ulpi_read_id(ulpi); + if (ret) + return ret; + } + ulpi->dev.parent = dev; ulpi->dev.bus = &ulpi_bus; ulpi->dev.type = &ulpi_dev_type;That should cover both cases. You would just have to create the IDs yourself in this case.
Right, I would have to make up some IDs in this case. I suppose I can use the qcom vendor ID 0x05c6 and then product ids 0 and 1 for HS phy and HSIC phy? That doesn't make me feel great because it's all made up, but I guess there's no other option. I hope they don't decide to start populating these ids in the future though and then we may have conflicting product ids. If that happens I suppose we can do a workaround based on compatible strings in the DT node. Fun! Nice side effect of all that is I can drop requesting the module by DT aliases and things become simpler. I'll try this out.