From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756027AbdLORGJ (ORCPT ); Fri, 15 Dec 2017 12:06:09 -0500 Received: from mga02.intel.com ([134.134.136.20]:38156 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755715AbdLORGF (ORCPT ); Fri, 15 Dec 2017 12:06:05 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.45,405,1508828400"; d="scan'208";a="12618707" Message-ID: <1513357470.7000.121.camel@linux.intel.com> Subject: Re: [PATCH V3] ACPI / LPSS: Add device link for CHT SD card dependency on I2C From: Andy Shevchenko To: Adrian Hunter , "Rafael J. Wysocki" , Mika Westerberg Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Carlo Caione , Hans de Goede Date: Fri, 15 Dec 2017 19:04:30 +0200 In-Reply-To: <1513342127-26646-1-git-send-email-adrian.hunter@intel.com> References: <1513342127-26646-1-git-send-email-adrian.hunter@intel.com> Organization: Intel Finland Oy Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.3-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2017-12-15 at 14:48 +0200, Adrian Hunter wrote: > Some Cherry Trail boards have a dependency between the SDHCI host > controller used for SD cards and an external PMIC accessed via I2C. > Add a > device link between the SDHCI host controller (consumer) and the I2C > adapter (supplier). > > This patch depends on a fix to devices links, namely commit > 0ff26c662d5f > ("driver core: Fix device link deferred probe"). And also either, > commit 126dbc6b49c8 ("PM: i2c-designware-platdrv: Clean up PM handling > in > probe"), or patch "PM / runtime: Fix handling of suppliers with > disabled > runtime PM". Reviewed-by: Andy Shevchenko > Signed-off-by: Adrian Hunter > --- > > > Changes in V3: > > I2C HID is from CHT so the cpu check is not necessary for now, > so > it was removed. > > Changes in V2: > > Add a comment about why it is necessary to hardcode the links > information in the code > > > drivers/acpi/acpi_lpss.c | 137 > +++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 137 insertions(+) > > diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c > index 7f2b02cc8ea1..d78c57a95b86 100644 > --- a/drivers/acpi/acpi_lpss.c > +++ b/drivers/acpi/acpi_lpss.c > @@ -427,6 +427,142 @@ static int register_device_clock(struct > acpi_device *adev, > return 0; > } > > +struct lpss_device_links { > + const char *supplier_hid; > + const char *supplier_uid; > + const char *consumer_hid; > + const char *consumer_uid; > + u32 flags; > +}; > + > +/* > + * The _DEP method is used to identify dependencies but instead of > creating > + * device links for every handle in _DEP, only links in the following > list are > + * created. That is necessary because, in the general case, _DEP can > refer to > + * devices that might not have drivers, or that are on different > buses, or where > + * the supplier is not enumerated until after the consumer is probed. > + */ > +static const struct lpss_device_links lpss_device_links[] = { > + {"808622C1", "7", "80860F14", "3", DL_FLAG_PM_RUNTIME}, > +}; > + > +static bool hid_uid_match(const char *hid1, const char *uid1, > + const char *hid2, const char *uid2) > +{ > + return !strcmp(hid1, hid2) && uid1 && uid2 && !strcmp(uid1, > uid2); > +} > + > +static bool acpi_lpss_is_supplier(struct acpi_device *adev, > + const struct lpss_device_links > *link) > +{ > + return hid_uid_match(acpi_device_hid(adev), > acpi_device_uid(adev), > + link->supplier_hid, link->supplier_uid); > +} > + > +static bool acpi_lpss_is_consumer(struct acpi_device *adev, > + const struct lpss_device_links > *link) > +{ > + return hid_uid_match(acpi_device_hid(adev), > acpi_device_uid(adev), > + link->consumer_hid, link->consumer_uid); > +} > + > +struct hid_uid { > + const char *hid; > + const char *uid; > +}; > + > +static int match_hid_uid(struct device *dev, void *data) > +{ > + struct acpi_device *adev = ACPI_COMPANION(dev); > + struct hid_uid *id = data; > + > + if (!adev) > + return 0; > + > + return hid_uid_match(acpi_device_hid(adev), > acpi_device_uid(adev), > + id->hid, id->uid); > +} > + > +static struct device *acpi_lpss_find_device(const char *hid, const > char *uid) > +{ > + struct hid_uid data = { > + .hid = hid, > + .uid = uid, > + }; > + > + return bus_find_device(&platform_bus_type, NULL, &data, > match_hid_uid); > +} > + > +static bool acpi_lpss_dep(struct acpi_device *adev, acpi_handle > handle) > +{ > + struct acpi_handle_list dep_devices; > + acpi_status status; > + int i; > + > + if (!acpi_has_method(adev->handle, "_DEP")) > + return false; > + > + status = acpi_evaluate_reference(adev->handle, "_DEP", NULL, > + &dep_devices); > + if (ACPI_FAILURE(status)) { > + dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n"); > + return false; > + } > + > + for (i = 0; i < dep_devices.count; i++) { > + if (dep_devices.handles[i] == handle) > + return true; > + } > + > + return false; > +} > + > +static void acpi_lpss_link_consumer(struct device *dev1, > + const struct lpss_device_links > *link) > +{ > + struct device *dev2; > + > + dev2 = acpi_lpss_find_device(link->consumer_hid, link- > >consumer_uid); > + if (!dev2) > + return; > + > + if (acpi_lpss_dep(ACPI_COMPANION(dev2), ACPI_HANDLE(dev1))) > + device_link_add(dev2, dev1, link->flags); > + > + put_device(dev2); > +} > + > +static void acpi_lpss_link_supplier(struct device *dev1, > + const struct lpss_device_links > *link) > +{ > + struct device *dev2; > + > + dev2 = acpi_lpss_find_device(link->supplier_hid, link- > >supplier_uid); > + if (!dev2) > + return; > + > + if (acpi_lpss_dep(ACPI_COMPANION(dev1), ACPI_HANDLE(dev2))) > + device_link_add(dev1, dev2, link->flags); > + > + put_device(dev2); > +} > + > +static void acpi_lpss_create_device_links(struct acpi_device *adev, > + struct platform_device > *pdev) > +{ > + int i; > + > + for (i = 0; i < ARRAY_SIZE(lpss_device_links); i++) { > + const struct lpss_device_links *link = > &lpss_device_links[i]; > + > + if (acpi_lpss_is_supplier(adev, link)) > + acpi_lpss_link_consumer(&pdev->dev, link); > + > + if (acpi_lpss_is_consumer(adev, link)) > + acpi_lpss_link_supplier(&pdev->dev, link); > + } > +} > + > static int acpi_lpss_create_device(struct acpi_device *adev, > const struct acpi_device_id *id) > { > @@ -500,6 +636,7 @@ static int acpi_lpss_create_device(struct > acpi_device *adev, > adev->driver_data = pdata; > pdev = acpi_create_platform_device(adev, dev_desc- > >properties); > if (!IS_ERR_OR_NULL(pdev)) { > + acpi_lpss_create_device_links(adev, pdev); > return 1; > } > -- Andy Shevchenko Intel Finland Oy