From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Chen Subject: Re: [PATCH 1/3] usb: misc: generic_onboard_hub: add generic onboard USB HUB driver Date: Tue, 8 Dec 2015 17:26:56 +0800 Message-ID: <20151208092655.GC16881@shlinux2> References: <1449538670-7954-1-git-send-email-peter.chen@freescale.com> <1449538670-7954-2-git-send-email-peter.chen@freescale.com> <20151208061905.GM11966@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <20151208061905.GM11966-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sascha Hauer Cc: shawnguo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, stern-nwvwT67g6+6dFdvTe/nMLpVzexx5G7lz@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, festevam-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, patryk-6+2coLtxvIyvnle+31E0rA@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On Tue, Dec 08, 2015 at 07:19:05AM +0100, Sascha Hauer wrote: > > + hub_data = devm_kzalloc(dev, sizeof(*hub_data), GFP_KERNEL); > > + if (!hub_data) > > + return -ENOMEM; > > + > > + if (dev->of_node) { > > + struct device_node *node = dev->of_node; > > + > > + hub_data->clk = devm_clk_get(dev, "external_clk"); > > Please drop such _clk suffixes. The context already makes it clear that > it's a clock. > Will change. > > + if (IS_ERR(hub_data->clk)) { > > + dev_dbg(dev, "Can't get external clock: %ld\n", > > + PTR_ERR(hub_data->clk)); > > + } > > + > > + /* > > + * Try to get the information for HUB reset, the > > + * default setting like below: > > + * > > + * - Reset state is low > > + * - The duration is 50us > > + */ > > + if (of_find_property(node, "hub-reset-active-high", NULL)) > > + reset_pol = 1; > > + > > + of_property_read_u32(node, "hub-reset-duration-us", > > + &duration_us); > > + > > + gpiod_reset = devm_gpiod_get_optional(dev, "hub-reset", > > + reset_pol ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW); > > + ret = PTR_ERR_OR_ZERO(gpiod_reset); > > + if (ret) { > > + dev_err(dev, "Failed to get reset gpio, err = %d\n", > > + ret); > > + return ret; > > + } > > + } else if (pdata) { > > + hub_data->clk = pdata->ext_clk; > > Passing clocks in platform_data is a no go. clocks must always be > retrieved with clk_get. Yes, you are right. > > > + duration_us = pdata->gpio_reset_duration_us; > > + reset_pol = pdata->gpio_reset_polarity; > > + > > + if (gpio_is_valid(pdata->gpio_reset)) { > > + ret = devm_gpio_request_one( > > + dev, pdata->gpio_reset, reset_pol > > + ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW, > > + dev_name(dev)); > > + if (!ret) > > + gpiod_reset = gpio_to_desc(pdata->gpio_reset); > > If the gpio is valid then being unable to get it is an error. I can't catch you, if the gpio is invalid, its descriptor will be NULL, then, the code will not do any gpio operation. > > Do you need this platform_data stuff at all? > If not, how can I cover the platform which does not use dts, but still uses these kinds of HUBs? -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html