From mboxrd@z Thu Jan 1 00:00:00 1970 From: gregory.clement@bootlin.com (Gregory CLEMENT) Date: Wed, 28 Feb 2018 17:24:12 +0100 Subject: [PATCH 2/2] usb: host: xhci-plat: Fix clock resource by adding a register clock In-Reply-To: (Manu Gautam's message of "Wed, 28 Feb 2018 21:39:05 +0530") References: <20180214161620.4401-1-gregory.clement@bootlin.com> <20180214161620.4401-3-gregory.clement@bootlin.com> Message-ID: <87zi3tdqvn.fsf@bootlin.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Manu, On mer., f?vr. 28 2018, Manu Gautam wrote: > Hi, > > > On 2/14/2018 9:46 PM, Gregory CLEMENT wrote: >> On Armada 7K/8K we need to explicitly enable the register clock. This >> clock is optional because not all the SoCs using this IP need it but at >> least for Armada 7K/8K it is actually mandatory. >> >> The change was done at xhci-plat level and not at a xhci-mvebu.c because, >> it is expected that other SoC would have this kind of constraint. >> >> The binding documentation is updating accordingly. >> >> Signed-off-by: Gregory CLEMENT >> --- >> Documentation/devicetree/bindings/usb/usb-xhci.txt | 5 +++- >> drivers/usb/host/xhci-plat.c | 33 ++++++++++++++++++---- >> drivers/usb/host/xhci.h | 3 +- >> 3 files changed, 33 insertions(+), 8 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt >> index e2ea59bbca93..e4b14511f4f8 100644 >> --- a/Documentation/devicetree/bindings/usb/usb-xhci.txt >> +++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt >> @@ -27,7 +27,10 @@ Required properties: >> - interrupts: one XHCI interrupt should be described here. >> >> Optional properties: >> - - clocks: reference to a clock >> + - clocks: reference to the clocks >> + - clock-names: mandatory if there is a second clock, in this case >> + the name must be "core" for the first clock and "reg" for the >> + second one >> - usb2-lpm-disable: indicate if we don't want to enable USB2 HW LPM >> - usb3-lpm-capable: determines if platform is USB3 LPM capable >> - quirk-broken-port-ped: set if the controller has broken port disable mechanism >> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c >> index 79afaac57ef6..fd0c399013a2 100644 >> --- a/drivers/usb/host/xhci-plat.c >> +++ b/drivers/usb/host/xhci-plat.c >> @@ -157,6 +157,7 @@ static int xhci_plat_probe(struct platform_device *pdev) >> struct resource *res; >> struct usb_hcd *hcd; >> struct clk *clk; >> + struct clk *reg_clk; >> int ret; >> int irq; >> >> @@ -226,17 +227,27 @@ static int xhci_plat_probe(struct platform_device *pdev) >> hcd->rsrc_len = resource_size(res); >> >> /* >> - * Not all platforms have a clk so it is not an error if the >> - * clock does not exists. >> + * Not all platforms have clks so it is not an error if the >> + * clock do not exist. >> */ >> + reg_clk = devm_clk_get(&pdev->dev, "reg"); >> + if (!IS_ERR(reg_clk)) { >> + ret = clk_prepare_enable(reg_clk); >> + if (ret) >> + goto put_hcd; >> + } else if (PTR_ERR(reg_clk) == -EPROBE_DEFER) { >> + ret = -EPROBE_DEFER; >> + goto put_hcd; >> + } >> + > > How about using clk_bulk_ APIs? I didn't know this API, but after having a look on it, it didn't match what I need. Indeed the second clock is "optional" to handle the backward compatibility. With the clk_bulk_ APIS all the clocks are mandatory. Thanks, Gregory > >> clk = devm_clk_get(&pdev->dev, NULL); >> if (!IS_ERR(clk)) { >> ret = clk_prepare_enable(clk); >> > > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- Gregory Clement, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering http://bootlin.com