From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751461AbeEDMaT (ORCPT ); Fri, 4 May 2018 08:30:19 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:7653 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751272AbeEDMaS (ORCPT ); Fri, 4 May 2018 08:30:18 -0400 Subject: Re: [PATCH 1/2] HISI LPC: Reference static MFD cells for ACPI support To: Andy Shevchenko , , , References: <1525360119-102166-1-git-send-email-john.garry@huawei.com> <1525360119-102166-2-git-send-email-john.garry@huawei.com> <1525366486.21176.653.camel@linux.intel.com> CC: , , , , , , From: John Garry Message-ID: <8c2627fa-a350-9a39-6a54-c789b6a3546a@huawei.com> Date: Fri, 4 May 2018 13:29:53 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <1525366486.21176.653.camel@linux.intel.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.238] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/05/2018 17:54, Andy Shevchenko wrote: > On Thu, 2018-05-03 at 23:08 +0800, John Garry wrote: >> Currently for ACPI support the driver models the host as >> an MFD. For a device connected to the LPC bus, we dynamically >> create an MFD cell for that device, configuring the cell >> name and ACPI match parameters manually. This makes supporting >> named devices and also special setup handling for certain devices >> awkward, as we would need to introduce some special ACPI device >> handling according to device HID. >> >> To avoid this, create reference static MFD cells for known >> child devices, so when adding an MFD cell we can fix the cell >> platform data as required. For this, a setup callback function >> is added. Hi Andy, >> >> For now, only the IPMI cell is added. > >> +static const struct mfd_cell *hisi_lpc_acpi_mfd_get_cell(const char >> *hid) >> +{ >> + const struct hisi_lpc_acpi_mfd_cell *cell = >> hisi_lpc_acpi_mfd_cells; >> + >> + for (; cell && cell->mfd_cell.name; cell++) { >> + const struct mfd_cell *mfd_cell = &cell->mfd_cell; >> + const struct mfd_cell_acpi_match *acpi_match; >> + >> + acpi_match = mfd_cell->acpi_match; >> + if (!strcmp(acpi_match->pnpid, hid)) >> + return mfd_cell; >> + } >> + >> + return NULL; >> +} > > I'm not sure I understand why MFD core can't do it (as seen in lines > drivers/mfd/core.c:105 and below). > Right, I think MFD core does the same. >> + /* allocate the mfd cells, one per child */ >> + size = sizeof(*mfd_cells); >> mfd_cells = devm_kcalloc(hostdev, cell_num, size, >> GFP_KERNEL); >> if (!mfd_cells) >> return -ENOMEM; > > And since you have structures already, I'm not sure why you need another > allocation for them. Only what you would need is to apply resources and > call devm_mfd_add_devices() per each found device. I was creating a copy as the originals are in the hisi_lpc_acpi_mfd_cell struct type, while we would require an array of mfd_cells. > >> + cell = container_of(mfd_cell_ref, typeof(*cell), >> mfd_cell); > > Why we can't iterate over inherited type of objects directly? > We could do. Thanks, John