Sorry I forgot to add maintainer into CC. +Lee Jones Any comments on this patch. As a lot of Exynos PMU patch sets are dependent on this patch. Thanks, Pankaj Dubey > -----Original Message----- > From: Pankaj Dubey [mailto:pankaj.dubey@xxxxxxxxxxx] > Sent: Friday, August 22, 2014 1:40 PM > To: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-samsung-soc@xxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx > Cc: kgene.kim@xxxxxxxxxxx; linux@xxxxxxxxxxxxxxxx; arnd@xxxxxxxx; > vikas.sajjan@xxxxxxxxxxx; joshi@xxxxxxxxxxx; naushad@xxxxxxxxxxx; > thomas.ab@xxxxxxxxxxx; chow.kim@xxxxxxxxxxx; Tomasz Figa; Pankaj Dubey > Subject: [PATCH] mfd: syscon: Decouple syscon interface from syscon devices > > From: Tomasz Figa <t.figa@xxxxxxxxxxx> > > Currently a syscon entity can be only registered directly through a platform device > that binds to a dedicated 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. > > This patch decouples syscon object from syscon driver, so that it can be registered > from any driver in addition to the original "syscon" platform driver. > > Signed-off-by: Tomasz Figa <t.figa@xxxxxxxxxxx> > Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx> > --- > > RFC patch [1] was posted by Tomasz Figa. This patch addresses some of comments > given by Arnd to RFC patch, and further decouples syscon from device model. It also > gives flexibility of registering with syscon at early stage using device_node object. > > [1]: https://lkml.org/lkml/2014/6/17/331 > > drivers/mfd/syscon.c | 112 ++++++++++++++++++++++++++++---- > ------------ > include/linux/mfd/syscon.h | 14 ++++++ > 2 files changed, 86 insertions(+), 40 deletions(-) > > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index ca15878..a91db30 > 100644 > --- a/drivers/mfd/syscon.c > +++ b/drivers/mfd/syscon.c > @@ -14,6 +14,7 @@ > > #include <linux/err.h> > #include <linux/io.h> > +#include <linux/list.h> > #include <linux/module.h> > #include <linux/of.h> > #include <linux/of_address.h> > @@ -22,33 +23,32 @@ > #include <linux/platform_device.h> > #include <linux/regmap.h> > #include <linux/mfd/syscon.h> > +#include <linux/slab.h> > > -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; > -} > - > 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); > + > + return syscon ? syscon->regmap : ERR_PTR(-EPROBE_DEFER); > } > EXPORT_SYMBOL_GPL(syscon_node_to_regmap); > > @@ -68,24 +68,22 @@ struct regmap > *syscon_regmap_lookup_by_compatible(const char *s) } > EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible); > > -static int syscon_match_pdevname(struct device *dev, void *data) -{ > - return !strcmp(dev_name(dev), (const char *)data); > -} > - > struct regmap *syscon_regmap_lookup_by_pdevname(const char *s) { > - struct device *dev; > - struct syscon *syscon; > - > - dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s, > - syscon_match_pdevname); > - if (!dev) > - return ERR_PTR(-EPROBE_DEFER); > - > - syscon = dev_get_drvdata(dev); > + struct syscon *entry, *syscon = NULL; > + struct platform_device *pdev = NULL; > + > + spin_lock(&syscon_list_slock); > + list_for_each_entry(entry, &syscon_list, list) { > + pdev = of_find_device_by_node(entry->np); > + if (pdev && !strcmp(dev_name(&pdev->dev), s)) { > + syscon = entry; > + break; > + } > + } > + spin_unlock(&syscon_list_slock); > > - return syscon->regmap; > + return syscon ? syscon->regmap : ERR_PTR(-EPROBE_DEFER); > } > EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname); > > @@ -121,17 +119,49 @@ static struct regmap_config syscon_regmap_config = { > .reg_stride = 4, > }; > > +void of_syscon_unregister(struct device_node *np) { > + struct syscon *entry; > + > + spin_lock(&syscon_list_slock); > + > + list_for_each_entry(entry, &syscon_list, list) > + if (entry->np == np) { > + list_del(&entry->list); > + break; > + } > + > + spin_unlock(&syscon_list_slock); > +} > +EXPORT_SYMBOL_GPL(of_syscon_unregister); > + > +int of_syscon_register(struct device_node *np, struct regmap *regmap) { > + struct syscon *syscon; > + > + syscon = kzalloc(sizeof(*syscon), GFP_KERNEL); > + if (!syscon) > + return -ENOMEM; > + > + syscon->regmap = regmap; > + syscon->np = np; > + > + spin_lock(&syscon_list_slock); > + list_add_tail(&syscon->list, &syscon_list); > + spin_unlock(&syscon_list_slock); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(of_syscon_register); > + > static int syscon_probe(struct platform_device *pdev) { > struct device *dev = &pdev->dev; > struct syscon_platform_data *pdata = dev_get_platdata(dev); > - struct syscon *syscon; > + struct regmap *regmap; > struct resource *res; > void __iomem *base; > - > - syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL); > - if (!syscon) > - return -ENOMEM; > + int ret; > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > if (!res) > @@ -144,14 +174,16 @@ static int syscon_probe(struct platform_device *pdev) > syscon_regmap_config.max_register = res->end - res->start - 3; > if (pdata) > syscon_regmap_config.name = pdata->label; > - syscon->regmap = devm_regmap_init_mmio(dev, base, > + regmap = devm_regmap_init_mmio(dev, base, > &syscon_regmap_config); > - if (IS_ERR(syscon->regmap)) { > + if (IS_ERR(regmap)) { > dev_err(dev, "regmap init failed\n"); > - return PTR_ERR(syscon->regmap); > + return PTR_ERR(regmap); > } > > - platform_set_drvdata(pdev, syscon); > + ret = of_syscon_register(dev->of_node, regmap); > + if (ret) > + return ret; > > dev_dbg(dev, "regmap %pR registered\n", res); > > diff --git a/include/linux/mfd/syscon.h b/include/linux/mfd/syscon.h index > 75e543b..dc2807b 100644 > --- a/include/linux/mfd/syscon.h > +++ b/include/linux/mfd/syscon.h > @@ -18,8 +18,12 @@ > #include <linux/err.h> > > struct device_node; > +struct regmap; > > #ifdef CONFIG_MFD_SYSCON > +extern int of_syscon_register(struct device_node *np, struct regmap > +*regmap); extern void of_syscon_unregister(struct device_node *np); > + > extern struct regmap *syscon_node_to_regmap(struct device_node *np); extern > struct regmap *syscon_regmap_lookup_by_compatible(const char *s); extern struct > regmap *syscon_regmap_lookup_by_pdevname(const char *s); @@ -27,6 +31,16 > @@ extern struct regmap *syscon_regmap_lookup_by_phandle( > struct device_node *np, > const char *property); > #else > +static inline int of_syscon_register(struct device_node *np, > + struct regmap *regmap) > +{ > + return -ENOSYS; > +} > + > +static inline void of_syscon_unregister(struct device_node *np) { } > + > static inline struct regmap *syscon_node_to_regmap(struct device_node *np) { > return ERR_PTR(-ENOSYS); > -- > 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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