Subject: [PATCH v8 2/3] usb: dwc3: Add Qualcomm DWC3 glue layer driver

From: [email-masked] (Andy Gross)
Date: Fri, 12 Sep 2014 13:53:43 -0500

On Fri, Sep 12, 2014 at 12:47:04PM -0500, Felipe Balbi wrote:
> Hi,
> 
> On Fri, Sep 12, 2014 at 12:29:45PM -0500, Andy Gross wrote:
> > From: "Ivan T. Ivanov" <[email-masked]>
> > 
> > DWC3 glue layer is hardware layer around Synopsys DesignWare
> > USB3 core. Its purpose is to supply Synopsys IP with required
> > clocks, voltages and interface it with the rest of the SoC.
> > 
> > Signed-off-by: Ivan T. Ivanov <[email-masked]>
> > Signed-off-by: Andy Gross <[email-masked]>
> > ---
> >  drivers/usb/dwc3/Kconfig     |    9 +++
> >  drivers/usb/dwc3/Makefile    |    1 +
> >  drivers/usb/dwc3/dwc3-qcom.c |  133 ++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 143 insertions(+)
> >  create mode 100644 drivers/usb/dwc3/dwc3-qcom.c
> > 
> > diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> > index 785510a..e9f258e 100644
> > --- a/drivers/usb/dwc3/Kconfig
> > +++ b/drivers/usb/dwc3/Kconfig
> > @@ -80,6 +80,15 @@ config USB_DWC3_KEYSTONE
> >  	  Support of USB2/3 functionality in TI Keystone2 platforms.
> >  	  Say 'Y' or 'M' here if you have one such device
> >  
> > +config USB_DWC3_QCOM
> > +	tristate "Qualcomm Platforms"
> > +	depends on ARCH_QCOM || COMPILE_TEST
> > +	default USB_DWC3
> > +	select PHY_QCOM_DWC3
> 
> I would rather steer away from selecting the PHY as it prevents having
> PHYs as modules. Also, this will add a Kconfig warning for selecting a
> symbol that doesn't exist (yet).

True.  The one downside is people having to fish around to find the phy config
option.

> 
> If it's all the same with you, I can clean this up when applying.
> 

Thats fine.

> > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> > new file mode 100644
> > index 0000000..2067c04
> > --- /dev/null
> > +++ b/drivers/usb/dwc3/dwc3-qcom.c
> > @@ -0,0 +1,133 @@
> > +/* Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 and
> > + * only version 2 as published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + * GNU General Public License for more details.
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/err.h>
> > +#include <linux/io.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regulator/consumer.h>
> > +#include <linux/usb/phy.h>
> 
> doesn't look like you need regulator/consumer.h and usb/phy.h. I can
> clean it up when applying.

Ack, interim changes that should have been removed.  you can do that or I can
respin.... no big deal.

> 
> > +struct dwc3_qcom {
> > +	struct device		*dev;
> > +
> > +	struct clk		*core_clk;
> > +	struct clk		*iface_clk;
> > +	struct clk		*sleep_clk;
> > +};
> > +
> > +static int dwc3_qcom_probe(struct platform_device *pdev)
> > +{
> > +	struct device_node *node = pdev->dev.of_node;
> > +	struct dwc3_qcom *qdwc;
> > +	int ret = 0;
> > +
> > +	qdwc = devm_kzalloc(&pdev->dev, sizeof(*qdwc), GFP_KERNEL);
> > +	if (!qdwc)
> > +		return -ENOMEM;
> > +
> > +	platform_set_drvdata(pdev, qdwc);
> > +
> > +	qdwc->dev = &pdev->dev;
> > +
> > +	qdwc->core_clk = devm_clk_get(qdwc->dev, "core");
> > +	if (IS_ERR(qdwc->core_clk)) {
> > +		dev_dbg(qdwc->dev, "failed to get core clock\n");
> 
> this one would be a dev_err() since core can't work without its clock. I
> can fix when applying.

Right.  That's fine.

> -- 
> balbi

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