Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753980AbdLDOmb (ORCPT ); Mon, 4 Dec 2017 09:42:31 -0500 Received: from mga05.intel.com ([192.55.52.43]:13647 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752861AbdLDOm1 (ORCPT ); Mon, 4 Dec 2017 09:42:27 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.45,359,1508828400"; d="scan'208";a="12863910" Subject: Re: [PATCH] ACPI / LPSS: Add device link for CHT SD card dependency on I2C To: Hans de Goede , "Rafael J. Wysocki" , Mika Westerberg Cc: Andy Shevchenko , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Carlo Caione References: <1512390731-11171-1-git-send-email-adrian.hunter@intel.com> <1860f193-3300-c718-9a79-d6fb690810cf@intel.com> <626a88b4-cf71-fd94-d78f-3947bfc5f024@redhat.com> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: Date: Mon, 4 Dec 2017 16:41:45 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <626a88b4-cf71-fd94-d78f-3947bfc5f024@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7964 Lines: 225 On 04/12/17 16:33, Hans de Goede wrote: > Hi, > > On 04-12-17 15:30, Adrian Hunter wrote: >> On 04/12/17 15:48, Hans de Goede wrote: >>> Hi, >>> >>> Wouldn't it be easier to use the ACPI _DEP tracking for this, e.g. >> >> It is using _DEP, see acpi_lpss_dep() >> >>> add something like this to the the probe function: >>> >>>      struct acpi_device = ACPI_COMPANION(device); >>> >>>      if (acpi_device->dep_unmet) >>>          return -EPROBE_DEFER; >>> >>> No idea if this will work, but if it does work, using the deps described >>> in the ACPI tables seems like a better solution then hardcoding this. >> >> That would not work because there are other devices listed in the _DEP >> method so dep_unmet is always true.  So we are left checking _DEP but only >> for specific device dependencies. > > Ugh, understood thank you for explaining this. Perhaps it is a good idea > to mention in the commit message why acpi_dev->dep_unmet cannot be used > here? dep_unmet predates device links, but now we have device links, they are better anyway. > > Regards, > > Hans > > >>> On 04-12-17 13:32, 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". >>>> >>>> Signed-off-by: Adrian Hunter >>>> --- >>>>    drivers/acpi/acpi_lpss.c | 139 >>>> +++++++++++++++++++++++++++++++++++++++++++++++ >>>>    1 file changed, 139 insertions(+) >>>> >>>> diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c >>>> index 7f2b02cc8ea1..9d82f2f6c327 100644 >>>> --- a/drivers/acpi/acpi_lpss.c >>>> +++ b/drivers/acpi/acpi_lpss.c >>>> @@ -290,6 +290,11 @@ static void bsw_pwm_setup(struct lpss_private_data >>>> *pdata) >>>>        {} >>>>    }; >>>>    +static const struct x86_cpu_id cht_cpu[] = { >>>> +    ICPU(INTEL_FAM6_ATOM_AIRMONT),    /* Braswell, Cherry Trail */ >>>> +    {} >>>> +}; >>>> + >>>>    #else >>>>      #define LPSS_ADDR(desc) (0UL) >>>> @@ -427,6 +432,139 @@ 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; >>>> +    const struct x86_cpu_id *cpus; >>>> +    u32 flags; >>>> +}; >>>> + >>>> +static const struct lpss_device_links lpss_device_links[] = { >>>> +    {"808622C1", "7", "80860F14", "3", cht_cpu, 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 (link->cpus && !x86_match_cpu(link->cpus)) >>>> +            continue; >>>> + >>>> +        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 +638,7 @@ 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; >>>>        } >>>>   >>> >> >