From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Andersson Subject: Re: [PATCH 01/21] of: device: Support loading a module with OF based modalias Date: Mon, 27 Jun 2016 21:17:50 -0700 Message-ID: <20160628041750.GA1190@tuxbot> References: <20160626072838.28082-1-stephen.boyd@linaro.org> <20160626072838.28082-2-stephen.boyd@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pf0-f175.google.com ([209.85.192.175]:33079 "EHLO mail-pf0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750704AbcF1ERz (ORCPT ); Tue, 28 Jun 2016 00:17:55 -0400 Received: by mail-pf0-f175.google.com with SMTP id i123so2292453pfg.0 for ; Mon, 27 Jun 2016 21:17:54 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20160626072838.28082-2-stephen.boyd@linaro.org> Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Stephen Boyd Cc: linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Andy Gross , Neil Armstrong , Arnd Bergmann , Felipe Balbi , Rob Herring , devicetree@vger.kernel.org On Sun 26 Jun 00:28 PDT 2016, Stephen Boyd wrote: > In the case of ULPI devices, we want to be able to load the > driver before registering the device so that we don't get stuck > in a loop waiting for the phy module to appear and failing usb > controller probe. Currently we request the ulpi module via the > ulpi ids, but in the DT case we might need to request it with the > OF based modalias instead. Add a common function that allows > anyone to request a module with the OF based modalias. > > Cc: Rob Herring > Cc: > Signed-off-by: Stephen Boyd > --- > drivers/of/device.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/of_device.h | 6 ++++++ > 2 files changed, 56 insertions(+) > > diff --git a/drivers/of/device.c b/drivers/of/device.c > index fd5cfad7c403..f275e5beb736 100644 > --- a/drivers/of/device.c > +++ b/drivers/of/device.c > @@ -226,6 +226,56 @@ ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) > return tsize; > } > > +static ssize_t of_device_modalias_size(struct device *dev) > +{ > + const char *compat; > + int cplen, i; > + ssize_t csize; > + > + if ((!dev) || (!dev->of_node)) > + return -ENODEV; > + > + /* Name & Type */ > + csize = 5 + strlen(dev->of_node->name) + strlen(dev->of_node->type); It would be clearer if you replaced 5 with strlen("of:NT"), but... > + > + /* Get compatible property if any */ > + compat = of_get_property(dev->of_node, "compatible", &cplen); > + if (!compat) > + return csize; > + > + /* Find true end (we tolerate multiple \0 at the end */ > + for (i = (cplen - 1); i >= 0 && !compat[i]; i--) > + cplen--; > + if (!cplen) > + return csize; > + cplen++; > + > + /* Check space (need cplen+1 chars including final \0) */ > + return csize + cplen; > +} ...if I understand of_device_get_modalias() correctly you should be able to replace this function with: size = of_device_get_modalias(dev, NULL, 0); snprintf() will not write to NULL, csize will be larger than 0 so tsize will be returned before it will memcpy() to the buffer. > + > +int of_device_request_module(struct device *dev) > +{ > + char *str; > + ssize_t size; > + int ret; > + > + size = of_device_modalias_size(dev); > + if (size < 0) > + return size; > + > + str = kmalloc(size + 1, GFP_KERNEL); > + if (!str) > + return -ENOMEM; > + > + of_device_get_modalias(dev, str, size); > + str[size] = '\0'; > + ret = request_module(str); > + kfree(str); > + > + return ret; > +} > + Regards, Bjorn From mboxrd@z Thu Jan 1 00:00:00 1970 From: bjorn.andersson@linaro.org (Bjorn Andersson) Date: Mon, 27 Jun 2016 21:17:50 -0700 Subject: [PATCH 01/21] of: device: Support loading a module with OF based modalias In-Reply-To: <20160626072838.28082-2-stephen.boyd@linaro.org> References: <20160626072838.28082-1-stephen.boyd@linaro.org> <20160626072838.28082-2-stephen.boyd@linaro.org> Message-ID: <20160628041750.GA1190@tuxbot> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sun 26 Jun 00:28 PDT 2016, Stephen Boyd wrote: > In the case of ULPI devices, we want to be able to load the > driver before registering the device so that we don't get stuck > in a loop waiting for the phy module to appear and failing usb > controller probe. Currently we request the ulpi module via the > ulpi ids, but in the DT case we might need to request it with the > OF based modalias instead. Add a common function that allows > anyone to request a module with the OF based modalias. > > Cc: Rob Herring > Cc: > Signed-off-by: Stephen Boyd > --- > drivers/of/device.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/of_device.h | 6 ++++++ > 2 files changed, 56 insertions(+) > > diff --git a/drivers/of/device.c b/drivers/of/device.c > index fd5cfad7c403..f275e5beb736 100644 > --- a/drivers/of/device.c > +++ b/drivers/of/device.c > @@ -226,6 +226,56 @@ ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) > return tsize; > } > > +static ssize_t of_device_modalias_size(struct device *dev) > +{ > + const char *compat; > + int cplen, i; > + ssize_t csize; > + > + if ((!dev) || (!dev->of_node)) > + return -ENODEV; > + > + /* Name & Type */ > + csize = 5 + strlen(dev->of_node->name) + strlen(dev->of_node->type); It would be clearer if you replaced 5 with strlen("of:NT"), but... > + > + /* Get compatible property if any */ > + compat = of_get_property(dev->of_node, "compatible", &cplen); > + if (!compat) > + return csize; > + > + /* Find true end (we tolerate multiple \0 at the end */ > + for (i = (cplen - 1); i >= 0 && !compat[i]; i--) > + cplen--; > + if (!cplen) > + return csize; > + cplen++; > + > + /* Check space (need cplen+1 chars including final \0) */ > + return csize + cplen; > +} ...if I understand of_device_get_modalias() correctly you should be able to replace this function with: size = of_device_get_modalias(dev, NULL, 0); snprintf() will not write to NULL, csize will be larger than 0 so tsize will be returned before it will memcpy() to the buffer. > + > +int of_device_request_module(struct device *dev) > +{ > + char *str; > + ssize_t size; > + int ret; > + > + size = of_device_modalias_size(dev); > + if (size < 0) > + return size; > + > + str = kmalloc(size + 1, GFP_KERNEL); > + if (!str) > + return -ENOMEM; > + > + of_device_get_modalias(dev, str, size); > + str[size] = '\0'; > + ret = request_module(str); > + kfree(str); > + > + return ret; > +} > + Regards, Bjorn