From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933083AbcKIN30 (ORCPT ); Wed, 9 Nov 2016 08:29:26 -0500 Received: from mga01.intel.com ([192.55.52.88]:39563 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932642AbcKIN3V (ORCPT ); Wed, 9 Nov 2016 08:29:21 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,614,1473145200"; d="scan'208";a="1082814761" Subject: Re: [RFC 2/2] mmc: sdhci-pci: Use ACPI to get max frequency for Intel byt sdio host controller sub-vended by NI To: Zach Brown , ulf.hansson@linaro.org References: <1478635635-14953-1-git-send-email-zach.brown@ni.com> <1478635635-14953-3-git-send-email-zach.brown@ni.com> Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: Date: Wed, 9 Nov 2016 15:24:24 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <1478635635-14953-3-git-send-email-zach.brown@ni.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/11/16 22:07, Zach Brown wrote: > On NI 9037 boards the max SDIO frequency is limited by trace lengths > and other layout choices. The max SDIO frequency is stored in an ACPI > table, as MXFQ. > > The driver reads the ACPI entry MXFQ during sdio_probe_slot and sets the > f_max field of the host with it. > > Signed-off-by: Nathan Sullivan > Reviewed-by: Jaeden Amero > Reviewed-by: Josh Cartwright > Signed-off-by: Zach Brown > --- > drivers/mmc/host/sdhci-pci-core.c | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c > index c333ce2..4ac7f16 100644 > --- a/drivers/mmc/host/sdhci-pci-core.c > +++ b/drivers/mmc/host/sdhci-pci-core.c > @@ -27,6 +27,7 @@ > #include > #include > #include > +#include > > #include "sdhci.h" > #include "sdhci-pci.h" > @@ -377,6 +378,35 @@ static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot) > > static int ni_byt_sdio_probe_slot(struct sdhci_pci_slot *slot) > { > +#ifdef CONFIG_ACPI > + /* Get max freq from ACPI for NI hardware */ > + acpi_handle acpi_hdl; > + acpi_status status; > + struct acpi_buffer acpi_result = { > + ACPI_ALLOCATE_BUFFER, NULL }; > + union acpi_object *acpi_buffer; > + int max_freq; > + > + status = acpi_get_handle(ACPI_HANDLE(&slot->chip->pdev->dev), "MXFQ", > + &acpi_hdl); Is "MXFQ" an object that has already been deployed or are you inventing it now? In the latter case, did you consider device properties as an alternative? > + if (ACPI_FAILURE(status)) > + return -ENODEV; > + > + status = acpi_evaluate_object(acpi_hdl, NULL, > + NULL, &acpi_result); > + if (ACPI_FAILURE(status)) > + return -EINVAL; > + > + acpi_buffer = (union acpi_object *)acpi_result.pointer; > + > + if (acpi_buffer->type != ACPI_TYPE_INTEGER) > + return -EINVAL; > + > + max_freq = acpi_buffer->integer.value; > + > + slot->host->mmc->f_max = max_freq * 1000000; > +#endif > + > slot->host->mmc->caps |= MMC_CAP_POWER_OFF_CARD | MMC_CAP_NONREMOVABLE; > return 0; > } >