From mboxrd@z Thu Jan 1 00:00:00 1970 From: balbi@ti.com (Felipe Balbi) Date: Tue, 16 Sep 2014 13:29:21 -0500 Subject: [Patch v9 1/3] usb: dwc3: qcom: Add device tree binding In-Reply-To: <20140916181543.GA19101@usblab-sd-06.qualcomm.com> References: <1410550088-8754-1-git-send-email-agross@codeaurora.org> <1410550088-8754-2-git-send-email-agross@codeaurora.org> <20140916181543.GA19101@usblab-sd-06.qualcomm.com> Message-ID: <20140916182920.GF19010@saruman.home> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, On Tue, Sep 16, 2014 at 11:15:43AM -0700, Jack Pham wrote: > Hi Andy, > > On Fri, Sep 12, 2014 at 02:28:06PM -0500, Andy Gross wrote: > > +Example device nodes: > > + > > + hs_phy: phy at 100f8800 { > > + compatible = "qcom,dwc3-hs-usb-phy"; > > + reg = <0x100f8800 0x30>; > > Just wanted to point out that in our downstream code, the glue > device/driver, i.e. "qcom,dwc3", does claim an entire register region > that encompasses the same registers used by these PHYs. I noticed you're > not adding a reg resource to the glue node below in this patchset. In > order to allow multiple devices to use the overlapping regions, we avoid > calling devm_ioremap_resource() and instead call devm_ioremap_nocache() > directly which bypasses the request_mem_region() call, which I don't > think is an entirely correct thing to do. > > On the other hand I'm trying to think of use cases on our other SOCs > (MSM8974, APQ8084) where the glue actually would need access to the same > or adjacent IO registers that couldn't just be handled directly by these > PHY drivers. Should we accommodate for the potential of overlapping > regions or should we just hold the line here and maybe only expose with > finer granularity the registers that will actually be needed by the PHYs > & glue respectively? I prefer to keep things separated. Glue only needs to access whatever belongs to glue. If a register related to PHY settings, it should be in the PHY address space. cheers -- balbi -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: