linux-kernel - Re: [PATCH 5/7] usb: gadget: udc: add Renesas RZ/N1 USBF controller support

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Message-ID: <20221107162319.7945f241@bootlin.com>
Date:   Mon, 7 Nov 2022 16:23:19 +0100
From:   Herve Codina <herve.codina@...tlin.com>
To:     Geert Uytterhoeven <geert@...ux-m68k.org>
Cc:     Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Magnus Damm <magnus.damm@...il.com>,
        Gareth Williams <gareth.williams.jx@...esas.com>,
        linux-renesas-soc@...r.kernel.org, linux-clk@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-usb@...r.kernel.org,
        Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
        Miquel Raynal <miquel.raynal@...tlin.com>
Subject: Re: [PATCH 5/7] usb: gadget: udc: add Renesas RZ/N1 USBF controller
 support

Hi Geert,

On Mon, 7 Nov 2022 15:37:40 +0100
Geert Uytterhoeven <geert@...ux-m68k.org> wrote:

> Hi Hervé,
> 
> On Mon, Nov 7, 2022 at 3:00 PM Herve Codina <herve.codina@...tlin.com> wrote:
> > Add support for the Renesas USBF controller.
> > This controller is an USB2.0 UDC controller available in the
> > Renesas r9a06g032 SoC (RZ/N1 family).
> >
> > Signed-off-by: Herve Codina <herve.codina@...tlin.com>  
> 
> > --- /dev/null
> > +++ b/drivers/usb/gadget/udc/renesas_usbf.c  
> 
> > +struct usbf_udc {
> > +       struct usb_gadget               gadget;
> > +       struct usb_gadget_driver        *driver;
> > +       struct device                   *dev;
> > +       struct clk_bulk_data            *clocks;
> > +       int                             nclocks;
> > +       void __iomem                    *regs;
> > +       spinlock_t                      lock;
> > +       bool                            is_remote_wakeup;
> > +       bool                            is_usb_suspended;
> > +       struct usbf_ep                  ep[USBF_NUM_ENDPOINTS];
> > +       /* for EP0 control messages */
> > +       enum usbf_ep0state              ep0state;
> > +       struct usbf_req                 setup_reply;
> > +       u8                              ep0_buf[USBF_EP0_MAX_PCKT_SIZE];
> > +};  
> 
> > +static int usbf_probe(struct platform_device *pdev)
> > +{
> > +       struct device *dev = &pdev->dev;
> > +       struct usbf_udc *udc;
> > +       struct usbf_ep *ep;
> > +       bool h2mode;
> > +       int irq;
> > +       int ret;
> > +       int i;
> > +
> > +       ret = r9a06g032_sysctrl_get_usb_h2mode(&h2mode);
> > +       if (ret)
> > +               return ret;
> > +       if (h2mode) {
> > +               dev_warn(dev, "Disabled in H2 (host) mode\n");
> > +               return -ENODEV;
> > +       }
> > +
> > +       udc = devm_kzalloc(dev, sizeof(*udc), GFP_KERNEL);
> > +       if (!udc)
> > +               return -ENOMEM;
> > +       platform_set_drvdata(pdev, udc);
> > +
> > +       udc->dev = dev;
> > +       spin_lock_init(&udc->lock);
> > +
> > +       udc->regs = devm_platform_ioremap_resource(pdev, 0);
> > +       if (IS_ERR(udc->regs))
> > +               return PTR_ERR(udc->regs);
> > +
> > +       devm_pm_runtime_enable(&pdev->dev);
> > +       ret = pm_runtime_resume_and_get(&pdev->dev);
> > +       if (ret < 0)
> > +               return ret;
> > +
> > +       ret = devm_clk_bulk_get_all(dev, &udc->clocks);
> > +       if (ret < 1) {
> > +               dev_err(dev, "failed to get clocks %d\n", ret);
> > +               return ret;
> > +       }
> > +       udc->nclocks = ret;
> > +
> > +       ret = clk_bulk_prepare_enable(udc->nclocks, udc->clocks);
> > +       if (ret) {
> > +               dev_err(dev, "can not enable the clock\n");
> > +               return ret;
> > +       }  
> 
> As this driver only enables/disables the clocks, perhaps you could
> just delegate this to Runtime PM (through the clock domain pointed
> by the power-domains property in DT), and drop the .clocks and
> .nclocks fields?

Yes, indeed.
I tested it and it works.
I will remove the the clocks handling from this driver in v2 series.

> 
> > +clk_disable:
> > +       clk_bulk_disable_unprepare(udc->nclocks, udc->clocks);
> > +       return ret;
> > +}
> > +
> > +static int usbf_remove(struct platform_device *pdev)
> > +{
> > +       struct usbf_udc *udc = platform_get_drvdata(pdev);
> > +
> > +       usb_del_gadget_udc(&udc->gadget);
> > +
> > +       clk_bulk_disable_unprepare(udc->nclocks, udc->clocks);
> > +
> > +       pm_runtime_put(&pdev->dev);
> > +
> > +       return 0;
> > +}  
> 
> > +MODULE_AUTHOR("Herve Codina <herve.codina@...tlin.com>");  
> 
> Hervé? ;-)

Just to be consistent with other places where my email appears,
I keep "Herve" :)

> 
> > +MODULE_DESCRIPTION("Renesas R-Car Gen3 & RZ/N1 USB Function driver");
> > +MODULE_LICENSE("GPL");  
> 
> > --
> > 2.37.3
> >  
> 
> 
> --
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds

Thanks for this review,
Hervé

-- 
Hervé Codina, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com