From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dong Aisheng Subject: Re: [PATCH v3] mfd: syscon: Decouple syscon interface from platform devices Date: Wed, 17 Sep 2014 16:58:42 +0800 Message-ID: <20140917085818.GA10285@shlinux1.ap.freescale.net> References: <1410935510-1567-1-git-send-email-pankaj.dubey@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1410935510-1567-1-git-send-email-pankaj.dubey@samsung.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Pankaj Dubey Cc: kgene.kim@samsung.com, linux@arm.linux.org.uk, arnd@arndb.de, naushad@samsung.com, linux-kernel@vger.kernel.org, tomasz.figa@gmail.com, linux-samsung-soc@vger.kernel.org, thomas.ab@samsung.com, vikas.sajjan@samsung.com, chow.kim@samsung.com, joshi@samsung.com, lee.jones@linaro.org, linux-arm-kernel@lists.infradead.org List-Id: linux-samsung-soc@vger.kernel.org On Wed, Sep 17, 2014 at 12:01:50PM +0530, Pankaj Dubey wrote: > Currently a syscon entity can be only registered directly through a > platform device that binds to a dedicated syscon driver. However in > certain use cases it is desirable to make a device used with another > driver a syscon interface provider. > > For example, certain SoCs (e.g. Exynos) contain system controller > blocks which perform various functions such as power domain control, > CPU power management, low power mode control, but in addition contain > certain IP integration glue, such as various signal masks, > coprocessor power control, etc. In such case, there is a need to have > a dedicated driver for such system controller but also share registers > with other drivers. The latter is where the syscon interface is helpful. > > In case of DT based platforms, this patch decouples syscon object from > syscon platform driver, and allows to create syscon objects first time > when it is required by calling of syscon_regmap_lookup_by APIs and keep > a list of such syscon objects along with syscon provider device_nodes > and regmap handles. > > For non-DT based platforms, this patch keeps syscon platform driver > structure where is can be probed and such non-DT based drivers can use > syscon_regmap_lookup_by_pdev API and get access to regmap handles. > Once all users of "syscon_regmap_lookup_by_pdev" migrated to DT based, > we can completly remove platform driver of syscon, and keep only helper > functions to get regmap handles. > > Suggested-by: Arnd Bergmann > Suggested-by: Tomasz Figa > Tested-by: Vivek Gautam > Signed-off-by: Pankaj Dubey > --- > V2 of this patchset and related discussion can be found here [1]. > > Changes since v2: > - Added back platform device support from syscon, with one change that > syscon will not be probed for DT based platform. > - Added back syscon_regmap_lookup_by_pdevname API so that non-DT base > users of syscon will not be broken. > - Removed unwanted change in syscon.h. > - Modified Signed-off-by list, added Suggested-by of Tomasz Figa and > Arnd Bergmann. > - Added Tested-by of Vivek Gautam for testing on Exynos platform. > > Changes since v1: > - Removed of_syscon_unregister function. > - Modified of_syscon_register function and it will be used by syscon.c > to create syscon objects whenever required. > - Removed platform device support from syscon. > - Removed syscon_regmap_lookup_by_pdevname API support. > - As there are significant changes w.r.t patchset v1, I am taking over > author for this patchset from Tomasz Figa. > > [1]: https://lkml.org/lkml/2014/9/2/299 > > drivers/mfd/syscon.c | 78 ++++++++++++++++++++++++++++++++++++-------------- > 1 file changed, 57 insertions(+), 21 deletions(-) > > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c > index ca15878..4a4bad9 100644 > --- a/drivers/mfd/syscon.c > +++ b/drivers/mfd/syscon.c > @@ -15,40 +15,49 @@ > #include > #include > #include > +#include > #include > #include > -#include > #include > #include > #include > #include > +#include > > static struct platform_driver syscon_driver; > > +static DEFINE_SPINLOCK(syscon_list_slock); > +static LIST_HEAD(syscon_list); > + > struct syscon { > + struct device_node *np; > struct regmap *regmap; > + struct list_head list; > }; > > -static int syscon_match_node(struct device *dev, void *data) > -{ > - struct device_node *dn = data; > - > - return (dev->of_node == dn) ? 1 : 0; > -} > +static struct syscon *of_syscon_register(struct device_node *np); > > struct regmap *syscon_node_to_regmap(struct device_node *np) > { > - struct syscon *syscon; > - struct device *dev; > + struct syscon *entry, *syscon = NULL; > > - dev = driver_find_device(&syscon_driver.driver, NULL, np, > - syscon_match_node); > - if (!dev) > - return ERR_PTR(-EPROBE_DEFER); > + spin_lock(&syscon_list_slock); > > - syscon = dev_get_drvdata(dev); > + list_for_each_entry(entry, &syscon_list, list) > + if (entry->np == np) { > + syscon = entry; > + break; > + } > > - return syscon->regmap; > + spin_unlock(&syscon_list_slock); > + > + if (!syscon) > + syscon = of_syscon_register(np); > + > + if (!IS_ERR(syscon)) > + return syscon->regmap; > + > + return ERR_CAST(syscon); > } > EXPORT_SYMBOL_GPL(syscon_node_to_regmap); > > @@ -110,17 +119,45 @@ struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np, > } > EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle); > > -static const struct of_device_id of_syscon_match[] = { > - { .compatible = "syscon", }, > - { }, > -}; > - > static struct regmap_config syscon_regmap_config = { > .reg_bits = 32, > .val_bits = 32, > .reg_stride = 4, > }; > > +static struct syscon *of_syscon_register(struct device_node *np) > +{ > + struct syscon *syscon; > + struct regmap *regmap; > + void __iomem *base; > + > + if (!of_device_is_compatible(np, "syscon")) > + return ERR_PTR(-EINVAL); > + > + syscon = kzalloc(sizeof(*syscon), GFP_KERNEL); > + if (!syscon) > + return ERR_PTR(-ENOMEM); > + > + base = of_iomap(np, 0); > + if (!base) > + return ERR_PTR(-ENOMEM); > + > + regmap = regmap_init_mmio(NULL, base, &syscon_regmap_config); Does a NULL device pointer work? I just tested on MX6SX SDB board and it seemed crashed at here in regmap_init function. Regards Dong Aisheng > + if (IS_ERR(regmap)) { > + pr_err("regmap init failed\n"); > + return ERR_CAST(regmap); > + } > + > + syscon->regmap = regmap; > + syscon->np = np; > + > + spin_lock(&syscon_list_slock); > + list_add_tail(&syscon->list, &syscon_list); > + spin_unlock(&syscon_list_slock); > + > + return syscon; > +} > + > static int syscon_probe(struct platform_device *pdev) > { > struct device *dev = &pdev->dev; > @@ -167,7 +204,6 @@ static struct platform_driver syscon_driver = { > .driver = { > .name = "syscon", > .owner = THIS_MODULE, > - .of_match_table = of_syscon_match, > }, > .probe = syscon_probe, > .id_table = syscon_ids, > -- > 1.7.9.5 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 From: b29396@freescale.com (Dong Aisheng) Date: Wed, 17 Sep 2014 16:58:42 +0800 Subject: [PATCH v3] mfd: syscon: Decouple syscon interface from platform devices In-Reply-To: <1410935510-1567-1-git-send-email-pankaj.dubey@samsung.com> References: <1410935510-1567-1-git-send-email-pankaj.dubey@samsung.com> Message-ID: <20140917085818.GA10285@shlinux1.ap.freescale.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Sep 17, 2014 at 12:01:50PM +0530, Pankaj Dubey wrote: > Currently a syscon entity can be only registered directly through a > platform device that binds to a dedicated syscon driver. However in > certain use cases it is desirable to make a device used with another > driver a syscon interface provider. > > For example, certain SoCs (e.g. Exynos) contain system controller > blocks which perform various functions such as power domain control, > CPU power management, low power mode control, but in addition contain > certain IP integration glue, such as various signal masks, > coprocessor power control, etc. In such case, there is a need to have > a dedicated driver for such system controller but also share registers > with other drivers. The latter is where the syscon interface is helpful. > > In case of DT based platforms, this patch decouples syscon object from > syscon platform driver, and allows to create syscon objects first time > when it is required by calling of syscon_regmap_lookup_by APIs and keep > a list of such syscon objects along with syscon provider device_nodes > and regmap handles. > > For non-DT based platforms, this patch keeps syscon platform driver > structure where is can be probed and such non-DT based drivers can use > syscon_regmap_lookup_by_pdev API and get access to regmap handles. > Once all users of "syscon_regmap_lookup_by_pdev" migrated to DT based, > we can completly remove platform driver of syscon, and keep only helper > functions to get regmap handles. > > Suggested-by: Arnd Bergmann > Suggested-by: Tomasz Figa > Tested-by: Vivek Gautam > Signed-off-by: Pankaj Dubey > --- > V2 of this patchset and related discussion can be found here [1]. > > Changes since v2: > - Added back platform device support from syscon, with one change that > syscon will not be probed for DT based platform. > - Added back syscon_regmap_lookup_by_pdevname API so that non-DT base > users of syscon will not be broken. > - Removed unwanted change in syscon.h. > - Modified Signed-off-by list, added Suggested-by of Tomasz Figa and > Arnd Bergmann. > - Added Tested-by of Vivek Gautam for testing on Exynos platform. > > Changes since v1: > - Removed of_syscon_unregister function. > - Modified of_syscon_register function and it will be used by syscon.c > to create syscon objects whenever required. > - Removed platform device support from syscon. > - Removed syscon_regmap_lookup_by_pdevname API support. > - As there are significant changes w.r.t patchset v1, I am taking over > author for this patchset from Tomasz Figa. > > [1]: https://lkml.org/lkml/2014/9/2/299 > > drivers/mfd/syscon.c | 78 ++++++++++++++++++++++++++++++++++++-------------- > 1 file changed, 57 insertions(+), 21 deletions(-) > > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c > index ca15878..4a4bad9 100644 > --- a/drivers/mfd/syscon.c > +++ b/drivers/mfd/syscon.c > @@ -15,40 +15,49 @@ > #include > #include > #include > +#include > #include > #include > -#include > #include > #include > #include > #include > +#include > > static struct platform_driver syscon_driver; > > +static DEFINE_SPINLOCK(syscon_list_slock); > +static LIST_HEAD(syscon_list); > + > struct syscon { > + struct device_node *np; > struct regmap *regmap; > + struct list_head list; > }; > > -static int syscon_match_node(struct device *dev, void *data) > -{ > - struct device_node *dn = data; > - > - return (dev->of_node == dn) ? 1 : 0; > -} > +static struct syscon *of_syscon_register(struct device_node *np); > > struct regmap *syscon_node_to_regmap(struct device_node *np) > { > - struct syscon *syscon; > - struct device *dev; > + struct syscon *entry, *syscon = NULL; > > - dev = driver_find_device(&syscon_driver.driver, NULL, np, > - syscon_match_node); > - if (!dev) > - return ERR_PTR(-EPROBE_DEFER); > + spin_lock(&syscon_list_slock); > > - syscon = dev_get_drvdata(dev); > + list_for_each_entry(entry, &syscon_list, list) > + if (entry->np == np) { > + syscon = entry; > + break; > + } > > - return syscon->regmap; > + spin_unlock(&syscon_list_slock); > + > + if (!syscon) > + syscon = of_syscon_register(np); > + > + if (!IS_ERR(syscon)) > + return syscon->regmap; > + > + return ERR_CAST(syscon); > } > EXPORT_SYMBOL_GPL(syscon_node_to_regmap); > > @@ -110,17 +119,45 @@ struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np, > } > EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle); > > -static const struct of_device_id of_syscon_match[] = { > - { .compatible = "syscon", }, > - { }, > -}; > - > static struct regmap_config syscon_regmap_config = { > .reg_bits = 32, > .val_bits = 32, > .reg_stride = 4, > }; > > +static struct syscon *of_syscon_register(struct device_node *np) > +{ > + struct syscon *syscon; > + struct regmap *regmap; > + void __iomem *base; > + > + if (!of_device_is_compatible(np, "syscon")) > + return ERR_PTR(-EINVAL); > + > + syscon = kzalloc(sizeof(*syscon), GFP_KERNEL); > + if (!syscon) > + return ERR_PTR(-ENOMEM); > + > + base = of_iomap(np, 0); > + if (!base) > + return ERR_PTR(-ENOMEM); > + > + regmap = regmap_init_mmio(NULL, base, &syscon_regmap_config); Does a NULL device pointer work? I just tested on MX6SX SDB board and it seemed crashed at here in regmap_init function. Regards Dong Aisheng > + if (IS_ERR(regmap)) { > + pr_err("regmap init failed\n"); > + return ERR_CAST(regmap); > + } > + > + syscon->regmap = regmap; > + syscon->np = np; > + > + spin_lock(&syscon_list_slock); > + list_add_tail(&syscon->list, &syscon_list); > + spin_unlock(&syscon_list_slock); > + > + return syscon; > +} > + > static int syscon_probe(struct platform_device *pdev) > { > struct device *dev = &pdev->dev; > @@ -167,7 +204,6 @@ static struct platform_driver syscon_driver = { > .driver = { > .name = "syscon", > .owner = THIS_MODULE, > - .of_match_table = of_syscon_match, > }, > .probe = syscon_probe, > .id_table = syscon_ids, > -- > 1.7.9.5 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754399AbaIQJ6Y (ORCPT ); Wed, 17 Sep 2014 05:58:24 -0400 Received: from mail-bn1on0147.outbound.protection.outlook.com ([157.56.110.147]:64384 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753853AbaIQJ6W (ORCPT ); Wed, 17 Sep 2014 05:58:22 -0400 X-Greylist: delayed 1091 seconds by postgrey-1.27 at vger.kernel.org; Wed, 17 Sep 2014 05:58:21 EDT Date: Wed, 17 Sep 2014 16:58:42 +0800 From: Dong Aisheng To: Pankaj Dubey CC: , , , , , , , , , , , , Subject: Re: [PATCH v3] mfd: syscon: Decouple syscon interface from platform devices Message-ID: <20140917085818.GA10285@shlinux1.ap.freescale.net> References: <1410935510-1567-1-git-send-email-pankaj.dubey@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1410935510-1567-1-git-send-email-pankaj.dubey@samsung.com> User-Agent: Mutt/1.5.20 (2009-06-14) X-EOPAttributedMessage: 0 X-Forefront-Antispam-Report: CIP:192.88.168.50;CTRY:US;IPV:CAL;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10019020)(6009001)(51704005)(199003)(24454002)(189002)(104016003)(106466001)(33656002)(102836001)(76482002)(26826002)(85306004)(105606002)(95666004)(97736003)(110136001)(46406003)(50466002)(107046002)(77982003)(74502003)(90102001)(46102003)(81342003)(80022003)(74662003)(81542003)(79102003)(31966008)(15975445006)(83506001)(64706001)(47776003)(20776003)(84676001)(92566001)(92726001)(76176999)(54356999)(50986999)(99396002)(68736004)(83322001)(21056001)(44976005)(19580405001)(83072002)(4396001)(19580395003)(85852003)(6806004)(15202345003)(87936001)(23726002)(97756001)(42262002);DIR:OUT;SFP:1102;SCL:1;SRVR:CY1PR0301MB0634;H:tx30smr01.am.freescale.net;FPR:;MLV:ovrnspm;PTR:InfoDomainNonexistent;A:1;MX:1;LANG:en; X-Microsoft-Antispam: BCL:0;PCL:0;RULEID:;UriScan:; X-Forefront-PRVS: 0337AFFE9A Authentication-Results: spf=fail (sender IP is 192.88.168.50) smtp.mailfrom=Aisheng.Dong@freescale.com; X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 17, 2014 at 12:01:50PM +0530, Pankaj Dubey wrote: > Currently a syscon entity can be only registered directly through a > platform device that binds to a dedicated syscon driver. However in > certain use cases it is desirable to make a device used with another > driver a syscon interface provider. > > For example, certain SoCs (e.g. Exynos) contain system controller > blocks which perform various functions such as power domain control, > CPU power management, low power mode control, but in addition contain > certain IP integration glue, such as various signal masks, > coprocessor power control, etc. In such case, there is a need to have > a dedicated driver for such system controller but also share registers > with other drivers. The latter is where the syscon interface is helpful. > > In case of DT based platforms, this patch decouples syscon object from > syscon platform driver, and allows to create syscon objects first time > when it is required by calling of syscon_regmap_lookup_by APIs and keep > a list of such syscon objects along with syscon provider device_nodes > and regmap handles. > > For non-DT based platforms, this patch keeps syscon platform driver > structure where is can be probed and such non-DT based drivers can use > syscon_regmap_lookup_by_pdev API and get access to regmap handles. > Once all users of "syscon_regmap_lookup_by_pdev" migrated to DT based, > we can completly remove platform driver of syscon, and keep only helper > functions to get regmap handles. > > Suggested-by: Arnd Bergmann > Suggested-by: Tomasz Figa > Tested-by: Vivek Gautam > Signed-off-by: Pankaj Dubey > --- > V2 of this patchset and related discussion can be found here [1]. > > Changes since v2: > - Added back platform device support from syscon, with one change that > syscon will not be probed for DT based platform. > - Added back syscon_regmap_lookup_by_pdevname API so that non-DT base > users of syscon will not be broken. > - Removed unwanted change in syscon.h. > - Modified Signed-off-by list, added Suggested-by of Tomasz Figa and > Arnd Bergmann. > - Added Tested-by of Vivek Gautam for testing on Exynos platform. > > Changes since v1: > - Removed of_syscon_unregister function. > - Modified of_syscon_register function and it will be used by syscon.c > to create syscon objects whenever required. > - Removed platform device support from syscon. > - Removed syscon_regmap_lookup_by_pdevname API support. > - As there are significant changes w.r.t patchset v1, I am taking over > author for this patchset from Tomasz Figa. > > [1]: https://lkml.org/lkml/2014/9/2/299 > > drivers/mfd/syscon.c | 78 ++++++++++++++++++++++++++++++++++++-------------- > 1 file changed, 57 insertions(+), 21 deletions(-) > > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c > index ca15878..4a4bad9 100644 > --- a/drivers/mfd/syscon.c > +++ b/drivers/mfd/syscon.c > @@ -15,40 +15,49 @@ > #include > #include > #include > +#include > #include > #include > -#include > #include > #include > #include > #include > +#include > > static struct platform_driver syscon_driver; > > +static DEFINE_SPINLOCK(syscon_list_slock); > +static LIST_HEAD(syscon_list); > + > struct syscon { > + struct device_node *np; > struct regmap *regmap; > + struct list_head list; > }; > > -static int syscon_match_node(struct device *dev, void *data) > -{ > - struct device_node *dn = data; > - > - return (dev->of_node == dn) ? 1 : 0; > -} > +static struct syscon *of_syscon_register(struct device_node *np); > > struct regmap *syscon_node_to_regmap(struct device_node *np) > { > - struct syscon *syscon; > - struct device *dev; > + struct syscon *entry, *syscon = NULL; > > - dev = driver_find_device(&syscon_driver.driver, NULL, np, > - syscon_match_node); > - if (!dev) > - return ERR_PTR(-EPROBE_DEFER); > + spin_lock(&syscon_list_slock); > > - syscon = dev_get_drvdata(dev); > + list_for_each_entry(entry, &syscon_list, list) > + if (entry->np == np) { > + syscon = entry; > + break; > + } > > - return syscon->regmap; > + spin_unlock(&syscon_list_slock); > + > + if (!syscon) > + syscon = of_syscon_register(np); > + > + if (!IS_ERR(syscon)) > + return syscon->regmap; > + > + return ERR_CAST(syscon); > } > EXPORT_SYMBOL_GPL(syscon_node_to_regmap); > > @@ -110,17 +119,45 @@ struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np, > } > EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle); > > -static const struct of_device_id of_syscon_match[] = { > - { .compatible = "syscon", }, > - { }, > -}; > - > static struct regmap_config syscon_regmap_config = { > .reg_bits = 32, > .val_bits = 32, > .reg_stride = 4, > }; > > +static struct syscon *of_syscon_register(struct device_node *np) > +{ > + struct syscon *syscon; > + struct regmap *regmap; > + void __iomem *base; > + > + if (!of_device_is_compatible(np, "syscon")) > + return ERR_PTR(-EINVAL); > + > + syscon = kzalloc(sizeof(*syscon), GFP_KERNEL); > + if (!syscon) > + return ERR_PTR(-ENOMEM); > + > + base = of_iomap(np, 0); > + if (!base) > + return ERR_PTR(-ENOMEM); > + > + regmap = regmap_init_mmio(NULL, base, &syscon_regmap_config); Does a NULL device pointer work? I just tested on MX6SX SDB board and it seemed crashed at here in regmap_init function. Regards Dong Aisheng > + if (IS_ERR(regmap)) { > + pr_err("regmap init failed\n"); > + return ERR_CAST(regmap); > + } > + > + syscon->regmap = regmap; > + syscon->np = np; > + > + spin_lock(&syscon_list_slock); > + list_add_tail(&syscon->list, &syscon_list); > + spin_unlock(&syscon_list_slock); > + > + return syscon; > +} > + > static int syscon_probe(struct platform_device *pdev) > { > struct device *dev = &pdev->dev; > @@ -167,7 +204,6 @@ static struct platform_driver syscon_driver = { > .driver = { > .name = "syscon", > .owner = THIS_MODULE, > - .of_match_table = of_syscon_match, > }, > .probe = syscon_probe, > .id_table = syscon_ids, > -- > 1.7.9.5 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel