Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753320Ab1BEDZl (ORCPT ); Fri, 4 Feb 2011 22:25:41 -0500 Received: from LUNGE.MIT.EDU ([18.54.1.69]:36531 "EHLO lunge.queued.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751523Ab1BEDZj (ORCPT ); Fri, 4 Feb 2011 22:25:39 -0500 Date: Fri, 4 Feb 2011 19:25:35 -0800 From: Andres Salomon To: Mark Brown Cc: Dmitry Torokhov , Samuel Ortiz , linux-kernel@vger.kernel.org, Peter Ujfalusi , Liam Girdwood , Jaroslav Kysela , Takashi Iwai , Timur Tabi , linux-input@vger.kernel.org, alsa-devel@alsa-project.org Subject: Re: [PATCH 12/19] twl4030: mfd_cell is now implicitly available to drivers Message-ID: <20110204192535.329d2280@queued.net> In-Reply-To: <20110204183913.318e6664@debxo> References: <20110202195417.228e2656@queued.net> <20110202201522.72d37f1e@queued.net> <20110203060521.GA25739@core.coreip.homeip.net> <20110202223959.244b4a01@queued.net> <20110203065339.GA5592@core.coreip.homeip.net> <20110202230326.167fe873@queued.net> <20110203093154.GC21591@opensource.wolfsonmicro.com> <20110204183913.318e6664@debxo> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.20.1; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3724 Lines: 119 On Fri, 4 Feb 2011 18:39:13 -0800 Andres Salomon wrote: > On Thu, 3 Feb 2011 09:31:54 +0000 > Mark Brown wrote: > > > On Wed, Feb 02, 2011 at 11:03:26PM -0800, Andres Salomon wrote: > > > Dmitry Torokhov wrote: > > > > > > Then they are doing it incorrectly. One possible way is to have > > > > parent device carry relevant data in its drvdata and have > > > > children get it from there. > > > > > I believe some drivers are even using the parent device already. > > > See drivers/leds/leds-mc13783.c, for example, whose parent device > > > drvdata is used to pass around a struct mc13783 to its children. > > > Sounds like a possibility, will need to look into it further. > > > > That's the current best practice approach. > [rambling] > Even that would require the weird API of mfd_add_devices needing to be > passed the type of what's pointed to by the parent's drvdata. > Actually, how about something like the following? This would leave drvdata unaffected. diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c index d83ad0f..a324a83 100644 --- a/drivers/mfd/mfd-core.c +++ b/drivers/mfd/mfd-core.c @@ -25,6 +25,7 @@ static int mfd_add_device(struct device *parent, int id, { struct resource *res; struct platform_device *pdev; + struct mfd_platform_data pdata = { NULL, NULL }; int ret = -ENOMEM; int r; @@ -39,12 +40,18 @@ static int mfd_add_device(struct device *parent, int id, pdev->dev.parent = parent; platform_set_drvdata(pdev, cell->driver_data); + pdata.cell = cell; if (cell->data_size) { - ret = platform_device_add_data(pdev, - cell->platform_data, cell->data_size); - if (ret) + pdata.platform_data = kmemdup(cell->platform_data, + cell->data_size, GFP_KERNEL); + if (!pdata.platform_data) { + ret = -ENOMEM; goto fail_res; + } } + ret = platform_device_add_data(pdev, &pdata, sizeof(pdata)); + if (ret) + goto fail_pdata; for (r = 0; r < cell->num_resources; r++) { res[r].name = cell->resources[r].name; @@ -91,6 +98,9 @@ static int mfd_add_device(struct device *parent, int id, return 0; /* platform_device_del(pdev); */ +fail_pdata: + if (pdata.platform_data) + kfree(pdata.platform_data); fail_res: kfree(res); fail_device: @@ -122,6 +132,7 @@ EXPORT_SYMBOL(mfd_add_devices); static int mfd_remove_devices_fn(struct device *dev, void *unused) { + /* TODO: nuke pdata memory */ platform_device_unregister(to_platform_device(dev)); return 0; } diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h index 835996e..dbc52a2 100644 --- a/include/linux/mfd/core.h +++ b/include/linux/mfd/core.h @@ -55,6 +55,26 @@ struct mfd_cell { bool pm_runtime_no_callbacks; }; +/* simple wrapper for a platform device's pdata */ +struct mfd_platform_data { + void *platform_data; + struct mfd_cell *cell; +}; + +/* + * Given a platform device that's been created by mfd_add_devices(), fetch + * the mfd_cell that created it. + */ +static inline const struct mfd_cell *mfd_get_cell(struct platform_device *pdev) +{ + return ((struct mfd_platform_data *)pdev->dev.platform_data)->cell; +} + +static inline void *mfd_platform_data(struct platform_device *pdev) +{ + return ((struct mfd_platform_data *)pdev->dev.platform_data)->data; +} + extern int mfd_add_devices(struct device *parent, int id, const struct mfd_cell *cells, int n_devs, struct resource *mem_base, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/